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ForestGALES 2.5 User Manual

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1. A Forest GALES A wind risk decision support tool for forest management in Britain Version 2 5 CA Forest Research User manual C 2 Forest GALES A wind risk decision support tool for forest management in Britain Forestry Commission Edinburgh In association with Forest Research Crown Copyright 2015 Version 1 0 published by the Forestry Commission in 2000 Version 2 0 published in 2006 This Version 2 5 published in 2015 ISBN 978 0 85538 932 1 Keywords climate forestry forest management gales storm damage wind windthrow FCSWO001 FC JW WWW OCT15 Enquiries relating to this publication should be addressed to Forest Research Northern Research Station Roslin Midlothian EH25 9SY 0300 067 5900 forestgales support forestry gsi gov uk Acknowledgements The initial development of Forest GALES was part funded by the European Union as part of the STORMS Self Organising Thermal Operational Resource Management project Recent developments have been a partnership between Forest Research and INRA French National Institute for Agricultural Research Forest GALES project team Bruce Nicoll Sophie Hale Barry Gardiner Andrew Peace and Bill Rayner of Forest Research Software development Barry Gardiner Sophie Hale Juan Suarez Stephen Bathgate and Mark Brady of Forest Research Forest Research is the Forestry Commission s Research Agency and is the UK s foremost body for forest and tree rel
2. The initial spacing in metres based on square planting should be selected The range varies from 0 9 4 5 m depending on yield models available Age The age of the crop to be modelled The valid range varies between yield models Ages between published values are calculated using linear interpolation between the nearest younger and nearest older published value By default if the date of planting has been entered then the age of the stand will be calculated This will give the risk now It is possible however to change the date allowing the risk to be calculated at some other time The Tree details button If this button is pressed then the height diameter current spacing and volume of the trees will be displayed This is designed to provide information about the type of stand being modelled Other boxes The DAMS box the Controls box the Upwind edge effect box and the Wind damage risk box are identical to those described on pages 20 to 22 User defined yield models New yield models can be constructed for use within Forest GALES using a word processor or spreadsheet program Currently Forest GALES doesn t contain a user defined yield model helper Yield models must therefore be created using a word processor or Windows Excel The general layout of the yield model file is described below A Windows Excel template is included with Forest GALES in directory yldmodls userdefined and is called yieldmodel xls The format
3. 3 Type NY659932 in the Grid reference box 4 Left click Apply gt 17 will appear in the DAMS box Again try changing other options to see what happens EXAMPLES 3 38 ForestGALES 2 5 7 DAMS calculate DAMS score This example demonstrates how to obtain the DAMS score for a location based on ground measurements 1 Start ForestGALES and open a query form for Single stands predictions using yield models 2 Within the DAMS box select the Calculation button then left click Apply gt A new form will appear 3 Left click on the Exact calculation tab gt New options will appear By default 23 will appear in the DAMS box This would relate to a hill top site at 200 m elevation in the west of Scotland Pressing Apply would copy this value to the query form 4 To change the location left click on View map gt This will cause a new window to appear 5 Left click in the dark blue area in central Scotland north west of the Tay estuary 6 Press OK gt The wind zone value 3 should be placed into the Wind zone box and 15 will appear in the DAMS box 7 Select 100 in the Elevation box gt 13 will appear in the DAMS box 8 Enter Topex scores as shown in Table 6 Table 6 Example Topex values North 0 North east 3 South west East 5 West 1 FSA yY PU South east 10 gt 10 will appear in the DAMS box Again try changing other options to see what happens Research mode To access Research
4. In D h 4 2 gfadj where x is the distance from the forest edge m Note that it is necessary to ensure that 2 1 D h 0 91 gt 0 The factor gfadj 1 0 replaces the value of 1 5 used in versions of ForestGALES which was found during a comparison against observed damage to give critical wind speeds that were too low Hale et al 2015 Aerodynamic parameters The aerodynamic parameters in Equation 4 Zo and d can be calculated using the method of Raupach 1994 7 def J exp ved1 A Vcd1 A 8 Zo h d exp k y Y 9 A Ee de canopydepth Cp D 2 10 y gt max A 0 6 c A s R 2 1 11 In C 1 Wn In Cy where cdl 7 5 Cs 0 003 Cg 0 3 and Cw 2 canopybreadth is the maximum width of the canopy m canopydepth is the length of the live crown m and Cp drag coefficient is a measure of the streamlining of the crown in the wind which can be calculated from the experimental data in Mayhead 1973 Rudnicki et al 2004 or Vollsinger et al 2005 12 Co C u where u is the wind speed of interest m s As examples C 2 35 and n 0 51 for Sitka spruce and C 3 07 and n 0 75 for Scots pine with a maximum value of drag coefficient set at u 10 ms and a minimum value at u 25 m s Note that we divide the value of canopybreadth by 2 to get the average canopy width for the tree because we assume a rhomboid shape for the crown with the maximum width of the canopy defining the width of the rhomboi
5. Using the Tab key Pressing Tab causes the focus to move through each of the controls in turn The appearance of focus depends on the type of control For text boxes up down boxes and menus the focus is indicated by the background becoming blue For the buttons focus is indicated by a thin black border and a black dashed box around the caption and picture if present on the button When a control has focus pressing F1 will result in help being displayed that relates to the control A control which has focus can also be edited changed or activated as follows Text boxes Edit using the keyboard e g Stand 1D Up down boxes Edit using the keyboard e g spacing Menu boxes Edit using the up and down keys e g species Radio buttons Select using the up and down keys e g windfirm brown edge Buttons Use the Enter key to press the button e g Calculate DAMS or RUN Using shortcuts Shortcuts allow a combination of the ALT key plus a letter to be used to select an option The Alt key shortcuts in the main menu are Alt F Open File menu Alt M Open Mode menu Alt A Open DAMS menu Alt I Open Options menu Alt W Open Window menu Alt H Open Help menu Within ForestGALES the shortcut for a particular button is indicated by an underlined letter in the button caption USING ForestGALES 13 Getting help Help can be obtained either by clicking on a Help button selecting Help from the main menu or by pressing F1
6. directory is actually open as shown in Figure 9 by double clicking on it Otherwise you will get the message DAMS data not found in selected directory Figure 9 Windscores directory Directory Controla ieee H OK de Help windy mindig wind wind wind 1 ae mad XX Cancel Controls box Allows the user to run the model save inputs load a saved file print results close the form save defaults and obtain help Wind damage risk box Indicates the risk of uprooting or stem breakage occurring and the estimated return period The query forms for other modes are described in later sections of this manual Navigating Forest GALES Using the mouse As the mouse is moved over the query form any of the components can be selected by clicking the left mouse button If text boxes such as Stand ID up down boxes such as spacing or menu boxes such as species are selected then changes can be made to the box by either typing in text for the text and up down boxes or by selecting the arrow buttons at the right edge of the box for menus and up down boxes When one of these boxes is selected then pressing F1 will result in Help being displayed to describe the use of the box If the mouse is moved over one of the buttons then the appearance of the button will change Clicking the left hand mouse button will cause the button on the form to be pressed This can be used to run the model print the form etc
7. 39 40 43 44 46 47 50 52 53 E 54 J9 9 37 Introduction Wind is the major disturbance factor in European forests and it is responsible for more than 50 of all damage by volume The risk of wind damage is a significant constraint to forest management in Britain The first major storm to affect British commercial forests since major replanting started after World War I was in 1953 in northeast Scotland This has been followed by major storms in 1968 central Scotland 1976 Wales and central England 1987 southeast England 1990 southwest England and south Wales 2005 northwest England and northwest Scotland and 2012 central Scotland Damage levels ranged from 0 5 to almost 4 million cubic metres representing up to five times the normal annual cut for the affected region Wind damage results in both direct costs e g the additional cost of harvesting and indirect costs e g loss of amenity It impacts on silvicultural practice by restricting thinning and shortening rotations and it can lead to precautionary felling in forests at risk of windthrow in many parts of the country Wind damage is of particular concern on exposed sites or sites with soils that restrict the rooting depth of trees Windthrow is normally the main form of damage but wind snap can be locally important when trees are particularly well anchored Good forest management can significantly reduce the vulnerability of a forest to wind damage However
8. Dams Scoe al K Close Stand characteristics box This is identical to the Stand characteristics box in predictions using yield models see page 23 except that year of planting is not available since predictions through time calculates risk over the whole rotation not at just a single age Tree characteristics box This is identical to the Tree characteristics box described on page 24 except that age is not available DAMS box This is identical to the DAMS box described on page 20 Controls box This is identical to the Controls box described on page 21 except that a report cannot be created PREDICTIONS THROUGH TIME va User defined yield tables New yield tables can be constructed using the method described on pages 25 to 26 Viewing the results Figure 21 shows a typical results form The form has four areas a graphics window two tabular windows and a Controls box These are described below Figure 21 Results form for Single stand predictions through time a Stand Predictions Through Time ForesiGALES IED a Emi Foor Bren BP ico HE Excel Expor Average number of years until damage ge SNA 1 F Ratum Period pra A Age yrs Age Tun rss DEH Tephi Spacing Masiva vota Wit rmbabor described n Lee yeki Lae 2 20 2 120 30 0 010 5 T 20 A 140 1 5 Me ie o AI Trl 154 1151 11 El 6 d a cl a 4 Pa itd Bi A ih m 2 40 H Dd NO 5 E 7 8200 i7 0 M0 i 41 fi Ea ue _
9. PELTOLA H and KELLOMAKI S 2000 Comparison of two models for predicting the critical wind speeds required to damage coniferous trees Ecological Modelling 129 1 23 HALE S E GARDINER B PEACE A NICOLL B TAYLOR P and PIZZIRANI S 2015 Comparison and validation of three versions of a forest wind risk model Environmental Modelling and Software 68 27 41 LAVERS G M 1969 The strength properties of timbers Forest Product Research Laboratory Bulletin 50 2nd edition HMSO London MAYHEAD GJ 1973 Some drag coefficients for British forest trees derived from wind tunnel studies Agricultural Meteorology 12 123 130 NEILD S A and WOOD CJ 1999 Estimating stem and root anchorage flexibility in trees Tree Physiology 19 141 151 NICOLL B C GARDINER B A RAYNER B and PEACE AJ 2006 Anchorage of coniferous trees in relation to species soil type and rooting depth Canadian Journal of Forest Research 36 191 1883 QUINE C P 2000 Estimation of mean wind climate and probability of strong winds for wind risk assessment Forestry 73 247 258 QUINE C P and GARDINER B A 2007 Understanding how the interaction of wind and trees results in windthrow stem breakage and canopy gap formation In E Johnson and K Miyanishi eds Plant disturbance ecology the process and the response Academic Press Burlington MA USA 698p RAUPACH M R 1994 Simplified expressions for vegetation roughness length and z
10. Soil A Rooting depth 1 2 User 43 153 2 44 178 1 45 156 2 46 Soil B Rooting depth 1 2 User 47 135 8 48 157 9 49 138 5 50 Soil C Rooting depth 1 2 User 51 148 3 52 1725 RESEARCH MODE 45 46 ForestGALES 2 5 Ss loz 54 Soil D Rooting depth 1 2 User 55 1697 56 196 2 oy a 58 L58 OTM Scaling value 59 100 60 Maximum stem weight in each category kg 61 Soil A Rooting depth 1 2 User 62 519 63 893 64 519 65 Soil B Rooting depth 1 2 User 66 2068 67 1042 68 2068 69 L69 Soil C Rooting depth 1 2 User 70 1205 Vi 2o7 72 1205 73 L73 Soil D Rooting depth 1 2 User 74 1070 75 1012 76 1070 Weibull parameters In previous versions of ForestGALES Weibull_K was embedded as a constant within the code and Weibull_A was calculated from DAMS for each site Using Research mode in Forest GALES 2 5 in the six standard three single stand and three batch modes e Weibull_K is held within the external parameter file FGparameters txt and can easily be altered e Weibull_A can be read directly from the external parameter file or it can be calculated from DAMS if preferred A code within the parameter file switches between these two options If Weibull_A is calculated from DAMS the variables relating Weibull_A to DAMS can be altered in the parameter file See Equation 17 in the Technical appendix If you are working in a Batch mode the same settings apply to all stands in th
11. dbh for stem breakage SW is the weight of the bole of the tree kg multiplied by an average green density value typically 850 1000 kg m The remaining parameters are species specific Ceg Nm kg is an anchorage coefficient obtained from tree pulling experiments and is a function of species soil type and rooting depth The C eg values used in Forest GALES 2 5 were derived from reanalysis of data presented in Nicoll et al 2006 and provide a more consistent change in value for different depths of rooting than the values presented in that paper The parameter fino Is a factor to reduce wood strength due to the presence of knots usually between 0 8 to 1 Ruel et al 2010 and MOR is the green wood Modulus of Rupture Pa for the particular species derived from bending tests e g Lavers 1969 Gardiner et al 2000 and Quine and Gardiner 2007 showed that the mean bending moment at any height z in m on a tree can be derived from the aerodynamic stress on the forest canopy T PU the average spacing between trees D in m and the assumption that the wind loading acts on average at the height of the zero plane displacement d in m Thom 1971 3 M mean 2 d z pu D where wis the friction velocity m s and pis air density kg m This can be used to calculate the turning moment on a tree at height z above the ground in terms of the canopy top wind speed u h m s7 by assuming a logarithmic wind profile abov
12. group The Soil group option allows you to select whether the main soil type in the stand is a freely draining mineral soil a gleyed mineral soil a peaty mineral soil or a peat These four soil groups appear in the Soil group drop down menu Table 1 shows which individual soil types fall within each group All soils within each group are treated as having the same characteristics For example if you are not sure whether your soil is ironpan freely draining or brown earth freely draining it does not matter both will give the same result PREDICTIONS USING FIELD MEASUREMENTS 15 16 ForestGALES 2 5 Table 1 Soil groups available within Forest GALES indicating the soil types within each group A Freely draining B Gleyed mineral C Peaty mineral soils D Deep peats mineral soils soils Brown earth lronpan gleyed lronpan peaty Juncus or basin bogs freely draining Podzol gleyed Podzol peaty Molinia or flushed lronpan blanket bogs freely draining Brown earth gleyed Peaty gley Surface water gley CE Podzol or raised bogs freely draining Ground water gley Unflushed blanket bog Calcareous soil Eroded bog Rankers and skeletal soils Littoral soils Man made soils Rooting This describes the depth of rootable soil in the stand The options are 1 Shallow lt 80 cm and 2 Deep 280 cm Soil and rooting help If you need help deciding which soil group or rooting depth to choose for your site cl
13. in order to manage and minimise risk forest managers need information on the likely timing and magnitude of damage so that they are able to predict the level of risk and assess the implications of different management options The Forest GALES software Forest GALES is a computer based decision support system that assesses the risk of wind damage to conifer forests in Britain and compares the impacts of different silvicultural practices Forest GALES is recommended for use at forest scales rather than for individual stands because of inherent variability in predictions It is currently designed for use in stands of uniform age and species It works by calculating the wind speed at which damage is expected to occur based on stand and soil characteristics the critical wind speed It then uses this critical wind speed and the wind climate predicted from the stand location to calculate the probability of damage The model calculates the risk for a representative average tree within the stand and by implication the stand as a whole Forest GALES calculates both the risk of overturning windthrow and stem breakage allowing managers to assess the likelihood of the different types of damage For example comparable values of critical wind speeds indicate that similar proportions of overturning and breakage are likely if damage occurs whereas large differences e g gt 5 m per second would indicate much higher levels of the damage t
14. j E 7 Sint Foi A aoe Stand characteristics box Siandi FomdliALes Enorans Siti Spruce E Bun Sod Goran E laleyed mensia Hali lt 8h Piri Fam Tree characteristics box A Y Aulos Hit e A em El Repu lt Controls box Soa and Rooting Help Too height standin 00 El l Cuert Spatiala Pe al Mean DEH Jemi mo de Help Buren och hal E Open Fis ll pave File Dans lt Upandi Edge Effect Gu Gid Reletences Calodeton ond ed G DAMS box hiso da laal yl Cuida Ea lt ton Edge effect box wire Damage Rea a pand wind Damage Aik Srahe Cstealyandspeed Coieal wind sperd al h lt Wi nd damage risk box meatu 20 A Ges 1214585 meaa a 1 a rm TET nc 7 Wheeled acid ln FAS Stand characteristics box Describes the soil rooting depth spacing and where appropriate planting year Tree characteristics box Describes the size of the trees within the stand being modelled Upwind edge effect box States whether a new brown edge is present and if so the size of the gap created DAMS box Describes how windy the site is DAMS can be entered directly calculated exactly extracted from a pre calculated data file for a particular location or estimated roughly The layout of the box depends on which selection is chosen To locate the DAMS dataset required for pre calculated DAMS values select DAMS Alt D from the main menu and locate the directory Windscores Make sure that the Windscores
15. m a ran of a a Tik 2200 acaso hal ihe VDA A nol reached ay ih W cL ae Fora Sa Trion 07 WEAS d Te halo The WHC la The graphics window The graphics window indicates the return period in years for damaging storms at intervals throughout the rotation Typically as the trees grow older and taller the risk of wind damage increases and the return period therefore decreases The graph contains two lines The red line indicates the risk of overturning and the blue line indicates the risk of stem breakage The data relate to average trees i e with mean diameter and height based on the yield tables Details of the graph can be investigated as follows Zooming into the graph e Place the mouse cursor at the top left hand corner of the area you wish to zoom in to e Hold down the left mouse button e With the mouse button held down move the mouse to the lower right hand corner of the area you wish to zoom in to e Release the mouse button e The display will then change to the selected area Note there is a minimum area which can be selected and if a smaller area is selected then no zooming will occur 28 ForestGALES 2 5 Scrolling around the graph e Place the mouse cursor somewhere on the graph e Hold down the right mouse button e With the right button held down move the mouse e The graph will move as you do this Resetting the graph e Place the mouse cursor on the graph e Hold down the left hand
16. menu of thinning options will appear as you move the mouse over the options they are highlighted in turn 6 Left click on Intermediate with no delay 7 Left click on Run gt The values in the Probabilities boxes will change and should become 200 years for the Return period for overturning and 200 years for the Return period for breakage Again try changing other options to see what happens EXAMPLES 35 36 ForestGALES 2 5 4 DAMS This example demonstrates the use of DAMS as an input for the model 1 Start ForestGALES and open a query form for Single stand predictions using yield models in the same way as the previous example Set the options to Species Sitka spruce Soil group Gleyed mineral soil B Rooting Shallow lt 80 cm Yield classs 14 Thinning regime Crown thinning Initial spacing 1 7 m Age 44 DAMS Score 15 Windfirm edge Left click on Run gt This will give the probabilities of damage for a typical tree in a stand of YC 14 Sitka spruce planted at 1 7 m spacing with a crown thinning regime at an age of 44 The values in the Probabilities boxes will change and should become 200 years for Return period for overturning and 200 years for Return period for breakage Within the DAMS box use the up and down arrows to select 17 as the value of DAMS score The higher the DAMS score the windier the site Leave the options as they are and left click on Run gt The return periods should change to
17. mode click Options and then click Research mode or click Ctrl R see Figure 25 Figure 25 Research mode File Mode DAMS Options Window Help Select Wind Speed Units gt Research Mode _ _ e Research mode allows users greater flexibility in some aspects of using Forest GALES Specifically e A wide range of parameters have been extracted into external parameter files both general to the whole model and species specific e There is a facility to add user defined species yield models and rooting depth anchorage coefficient e There is a facility to set Weibull_A directly in the parameter file rather than calculate it from DAMS This can be used in the single stand modes and in the standard batch modes if the same Weibull_A and Weibull_K are to be applied to all stands being analysed e An additional batch mode has been included using field measurements where Weibull_A and Weibull_K are entered on the input form instead of DAMS This enables the Weibull parameters to be varied for each stand being analysed This mode is shown using an additional icon to the right of the six standard modes at the top of the Forest GALES main window This mode also allows very long files longer than 32994 lines to be processed e A detailed range of outputs are now optionally saved to file Click Help Help to access help files for Research mode There is also a Technical appendix detailing the equations
18. mouse button e With the left button held down move the mouse to the left and upwaras e The display will then revert to the original state Note there is a minimum area which can be selected and if a smaller area is selected then the graph will not reset Displaying new results The effect of changing the yield model used can be observed directly in the graphics window Go to the query form change any parameter press the Run button and the graphics display will change This allows the user to easily observe the effect of changing the thinning model or soil type or species for example The tabular data windows The table window on the left hand side indicates how return period changes with age and provides details on height diameter spacing and volume of the crop with age The date when the crop enters each Wind damage risk status WDRS is displayed in the table window on the right hand side Data can be exported as described below The results form controls box The controls that can be used on the results form are Print Form Alt P Prints the current query form Report Alt T Creates a report that contains all the information on the form The report can be printed or saved for later use Help Alt H Starts the Help system Excel Export Alt X Allows the user to export the tabular results to Windows Excel PREDICTIONS THROUGH TIME 29 30 ForestGALES 2 5 Batch mode Forest GALES has been designed t
19. predictions using field measurements A ap wed Dep Glee Cade ee arr ew vesaer dem ol CI How the model works The model uses data relating to individual trees to estimate the risk of damage to stands of trees by answering three questions 1 What force would be needed to uproot or break the tree 2 What wind speed would create the force required to damage the tree i e what is the threshold or critical wind speed 3 What is the probability of the threshold wind speed being exceeded What force would be needed to uproot or break the tree Trees fail in high winds either by stem breakage or by overturning as tree are uprooted depending largely on how well anchored they are Forest GALES calculates both the resistance of the stem to breakage and the resistance of the tree to uprooting Resistance to breakage is calculated based on theoretical work on stem strength that regards tree stems as structures combined with data on the wood strength and stiffness of different tree species Resistance to uprooting is calculated based on an extensive database of tree pulling experiments that relate tree characteristics to the force required to pull a tree over These experiments were conducted on a range of soil and cultivation types for many species The influence of cultivation and drainage is represented within ForestGALES by rooting depth However for some combinations of species soil type and rooting depth data are no
20. used to calculate Roughness 2 e Height above zero plane displacement at which we require wind speed m e Roughness of land surrounding forest m not used in this version of Forest GALES e Ua used in calculation of annual exceedance probability gt e Four parameters used in calculation of Uc used in calculation of annual exceedance probability e Weibull_K 4 e Code for Weibull_A calculation method 1 Entered directly or 2 Calculated from DAMS e Weibull_A used if code is 1 e Two parameters for calculating Weibull_A from DAMS used if code is 2 Refer to the Technical appendix to see how these values are used See Equation 10 See Equation 11 See Equation 18 See Equation 19 gt See Equation 20 See Equation 17 These Weibull parameters are not used in Batch Weibull mode The structure of the FGParameters txt file is shown below Lines with comments and parameter names begin with Parameter values are on the line below the parameter name RESEARCH MODE 4 42 ForestGALES 2 5 FGParameters txt FG2 5Res File containing constants model limits and aerodynamic parameters it Each comment describes the line below it SNOWDENSITY snow density kg m 150 K von Karman constant 9 0 4 10 RO air density kg m 11 1 2226 12 G acceleration due to gravity m s 18 281 14 TREE_HEIGHTS_FROM_EDGE number of tree heights from edge assumed to be in forest 182 16 BIGG
21. windier the climate on average GLOSSARY 32 ForestGALES 2 5 Further reading and useful sources of information Forestry Commission publications www forestry gov uk publications e Forest mensuration a handbook for practitioners FCBK039 e Forests and wind management to minimise damage FCBU1 14 e Rooting and stability in Sitka spruce FCBU040 e The identification of soils for forest management FCFG001 e Forest Yield a PC based yield model for forest management in Britain FCSW002 in prep Other publications e Wind and wind related damage to trees Cambridge University Press e Joint evaluation of storms forests vulnerability and their restoration Discussion Paper 9 European Forest Institute e Living with storm damage to forests what science can tell us 3 European Forest Institute Websites e Forest GALES www forestry gov uk fr forestgales Technical appendix Critical turning moments for overturning and breakage The critical turning moments for overturning and breaking of a tree can be derived using the formula in Gardiner et al 2000 1 M crit_over Creg SW 2 Merit break ZL fino MOR diam 32 where M is the total overturning moment in Nm resulting from wind loading and from the weight of the overhanging crown and diam is the diameter of the stem m M is calculated at the base of the tree diam do for overturning and either at the base of the tree or at breast height diam
22. 30 years for the Return period for overturning and 28 years for Return period for breakage It should be apparent that relatively small changes in DAMS result in large changes in calculated risk Again try changing other options to see what happens 5 DAMS rough guess This example demonstrates using a rough estimate of DAMS as an input for the model 1 Start ForestGALES and open a query form for Single stands predictions using yield models 2 Within the DAMS box select the Calculation button then click Apply gt A new form will appear 3 Left click on the Rough guess tab gt New options will appear 4 Select GB Region Scottish amp English Borders Elevation Mid Slope Shelter Exposed Aspect West gt 18 will appear in the DAMS box Pressing Apply would copy this value to the query form 5 In the GB Region box select central Wales gt 17 will appear in the DAMS box Again try changing other options to see what happens 6 DAMS grid reference This example demonstrates how to obtain the DAMS score for a specific grid reference 1 Start ForestGALES and open a query form for Single stands predictions using yield models 2 Within the DAMS box click the Grid Reference button Press Apply gt 15 will appear in the DAMS box This is the value of DAMS for NH180150 If Forest GALES cannot find the DAMS data it will ask you to locate it The Find files option in the Windows start up menu may be useful for this
23. 50 years may occur within a few years of each other The occurrence of a damaging storm does not alter the risk of further damage in subsequent years Wind damage risk status WDRS Wind damage risk status is a measure of the risk of damage either by overturning or stem breakage Six classes of WDRS exist These are colour coded as a visual guide to the user 1 2 green 3 4 orange 5 6 red as shown in Table 2 Table 2 Wind damage risk status WDRS and associated return periods oye Unlike the Windthrow hazard class WHC classes the risk status of a site will change over time If the risk status for stem breakage is greater than for overturning then stem breakage is likely to be the predominant form of damage whereas if the risk status Is greater for overturning than for breakage then uprooting is likely to be the predominant form of damage Windthrow hazard classification WHC The WHC class for the site based on the traditional system described in Forestry Commission Leaflet 85 Windthrow hazard classification using the DAMS score and soil type This is provided to allow comparisons to be made between the old and new system Predictions using yield models This type of prediction allows the user to calculate the risk of damage at a single point in time based on stand characteristics defined in yield models It is particularly useful when the mensurational characteristics of a stand are not known or
24. AMS score to the query form or Cancel to close the window without copying the value across This method is particularly useful for making general comparisons between sites An example of this method of obtaining DAMS is shown on page 37 Example 5 Figure 14 Rough guess box Result GB Region West amp North Coast Scotland amp Islands DAMS 23 Elevation Top of Hill E Controls meter wel Sheltered F Apply Aspect All F Y Help X Cancel Grid reference method In the DAMS box the user can select Grid reference and then enter the grid reference of the site the DAMS score if available will be displayed Example 6 page 37 shows the use of the grid reference method for obtaining DAMS Exact calculation method In the DAMS box select Calculation then click the Apply button The calculation box will appear Selecting the Exact calculation box Figure 15 will give the opportunity to calculate the exact DAMS score The Wind zone for the location can be found using the map that is displayed when View map is pressed DAMS scores and wind zone boundaries are discussed in Forestry Commission Research Information Note 230 Revised windiness scores for the windthrow hazard classification Elevation is entered together with the Topex values for each of eight compass directions TOPEX is the angle to the horizon in whole degrees in the particular compass direction with values less than zero being entered as zero The resultin
25. AP size of gap regarded as infinite 17 10 18 LIMIT defines resolution of Forest GALES model 19 0 01 20 CR Element drag coefficient 21 0 3 22 CS Surface drag coefficient 23 0 003 24 CW Constant ase 26 CALC_HT height above zpd at which we require wind speed 2il WO 28 FIELD_ZO Roughness of land surrounding forest 27 000 30 Ua 31 5 32 U_CT parameter for calculating U_C SUL Os 34 U_C2 parameter for calculating U_C 35 4 4345 36 U_C3 parameter for calculating U_C of SOS 38 U_C4 parameter for calculating U_C 29 12 9097 40 Weibull_K 41 1 85 42 Weibull A method Entered directly 1 Calc from DAMS 2 43 1 44 Weibull_A_Entered 45 6 46 Params for calc Weibull A A_Weibull DAMStoWeibullA1 DAMStoWeibullA2 DAMS 47 DAMStoWeibullAl 48 0 9626 49 DAMStoWeibullA2 50 0 4279 51 Number of sections in each metre length of trunk 52 1 Of E a aS Species parameter files Species parameter files must be stored in a directory called SpeciesParamFiles held in the root directory of Forest GALES 2 5 i e ForestGALES_2 5 SpeciesParamFiles it must not be moved from here Individual species parameter files are named XXParameters txt where XX is the two letter species code CP LP SP EL HL JL NS SS DF NF GF WH Forest GALES looks for SpeciesParamFiles XXParameters txt Three user defined species are also available in Research mode
26. Forest GALES draws together more than 30 years of knowledge and research into a user friendly decision support tool that will enable forest managers to estimate the probability of wind damage to conifer stands in Britain The software calculates the wind speed that would be expected to damage a stand of trees and it provides windiness scores DAMS for the whole of Britain It assesses the current level of risk of overturning and stem breakage and the change in risk over the lifetime of the crop in addition to assessing the effect on risk of thinning and the creation of brown edges ForestGALES is able to calculate the risk to any number of stands simultaneously Forestry Commission Silvan House 231 Corstorphine Road Edinburgh EH12 7AT www forestry gov uk
27. NIN 300 T ETIN 25 0 m s ism 12314536 BREAKAGE 20 HN eae MEF m s wHe E Weibull cakuleted from DAMS Stand characteristics box As for Predictions using field measurements the Stand characteristics box contains the Stand ID Soil group and Rooting options see page 15 The current stocking cannot be specified as this is taken from the yield tables Planting year A planting year can be specified This will automatically adjust the stand age to the present in the Tree characteristics box If you want to make a prediction into the future adjust the age of the stand see below instead of specifying a planting year PREDICTIONS USING YIELD MODELS 23 24 ForestGALES 2 5 Tree characteristics box When predictions are made using yield models the Tree characteristics box shows the same Species option as found in the predictions using field measurements see page 17 However the other options are different Yield class The thinning model regimes displayed will depend on the yield models available as described in the Forestry Commission software Forest Yield a PC based yield model for forest management in Britain Thinning regime e Intermediate thinning with no delay e Intermediate thinning with five year delay e Intermediate thinning with ten year delay e Line thinning with no delay e Line thinning with five year delay e Line thinning with ten year delay e Crown thinning e No thinning Initial spacing
28. NS Norway spruce IF Intermediate thinning five years delay SP Scots pine IT Intermediate thinning ten years delay LP Lodgepole pine LZ line thinning no delay CP Corsican pine LF line thinning five years delay EL European larch LT line thinning ten years delay JL Japanese larch CZ crown thinning HL Hybrid larch NO non thinning DF Douglas fir TI user defined thinning regime GF Grand fir T2 user defined thinning regime NF Noble fir T3 user defined thinning regime WH Western hemlock A user defined model for yield class 18 Sitka spruce for a non standard thinning regime planted initially at 2 0 m spacing would therefore be saved as 5518T120 yld The file should be saved in the directory yldmdls XxX where XX is the two letter species code indicated in Table 4 Ifa new model is created with an identical name to a model that already exists then the old model will be lost Using Windows Excel to create user defined yield models 1 Open the file yieldmodel xls in Windows Excel It is in the directory yldmdls userdefined wherever you have installed Forest GALES 2 Type data for the yield model into the template 3 Extra lines can be added as necessary If the template contains more lines than are needed then remember to delete the extra lines 4 Press File Save As 5 Choose the option Formatted Text Space delimited prn 6 The file must be saved in the directory XX where XX is the two character species code indicated in Tabl
29. Pressing Help starts the help system this allows the user to search for a particular topic or keyword Pressing F1 will display help relating to the component that has focus usually the last item where you clicked the mouse These help pages are therefore context sensitive 14 ForestGALES 2 5 Predictions using tield measurements This is the standard type of prediction It allows the user to calculate the risk of damage based on the stand s mensurational characteristics at a single point in time An example of this type of prediction is shown on page 33 Example 1 The user enters data that describe the site the tree crop and whether or not a new edge is present In individual stand predictions pressing Run will then calculate the probabilities of damage occurring based on the selected options Making predictions for multiple stands is explained on page 30 in the Batch mode section Stand characteristics box The Stand characteristics box Figure 10 allows you to describe the stand for which you wish to calculate the risk of damage Figure 10 Stand characteristics box Stand Characteristics Stand ID ForestGALES Sail Group B Gleyed mineral soils 7 Rooting E Shallow Rooting lt 80 cm Sol and Rooting Help f Curent Spacing m 2 0 f Curent Stocking Nha Stand ID An identification for the stand Note names longer than 25 characters will not print correctly if a report is produced Soil
30. above to an area of the hard disc where you know there are no requirements for administrator privileges the desktop is a good location This should avoid most security issues 3 Try running the installation file or Forest GALES2 5 as an administrator Right mouse click on the executable file and choose Run as administrator from the menu Figure 3 Figure 3 Run as administrator ForestGALES 2 5 Bin w amp Search E D r A p r r Marne late morder Y copyrightt 2602 20 _ FRROR L OG 1008 0015 1304 E ForestGAl FS Oven E bas indiv _rt rtf TE IER i Run as administrator rt otf A a repo Troubleshoot compatibility H report rif eS Help tiles By default Forest GALES accesses all help information from the file forestgales25_help_manual chm This is a compiled html file and should work in all versions of Windows If you are having problems with forestgales25_help_manual chm an optional alternative version of the help information is provided as the file forestgales25_help_manual hlp which is the classic type of Windows help file This can be set as the default help file in Forest GALES under the Help drop down menu in the Main form Figure 4 This file should work For versions of Windows earlier than Windows 7 2 For Windows 7 and Windows 8 under most circumstances after downloading and installing the Windows Help program WinHIp32 exe from http www microsoft com en us download details aspx id 91 Fig
31. ameters so the use of the Batch mode helper application is recommended However the input files can also be created from a spreadsheet If doing so it is recommended to add a line of input to the form using the Batch mode helper then clicking Save inputs Open the resulting file in Excel and use it to ensure correct formatting Note that DBH values can be entered in either cm 1 99 cm or in metres 0 01 0 99 m All outputs are written in cm When a batch file is opened using Open file on the query form a progress box appears When the file is loaded this is replaced with the message File successfully opened For very large files thousands of lines on occasion this progress box may appear to freeze Be patient and the file will open Batch mode helper The Batch mode helper allows the user to select inputs from menus and these are then written to the input area of the query form This is useful because Forest GALES uses coded values to describe the species and site rather than descriptions and these values may be difficult to remember For each prediction type the options are identical to those described for the corresponding query form in the Single stand prediction mode See the sections starting on pages 15 23 and 27 Note Clicking on Close causes both the helper and the Batch mode query form to be closed Unless you want to discard the inputs click on Calculate risk before closing the helper Controls box The controls
32. and small changes in the wind speed required to cause damage can be associated with large changes in the probability of damage occurring Having calculated the probability of damage this is converted to a return period for a damaging wind speed occurring This is the average interval between storms that are associated with damaging winds Wind damage risk status provides a rough estimate of risk ranging from Status 1 return period for damaging winds more than 100 years to Status 6 return period less than 10 years Using Forest GALES There are several ways to start the program The easiest is to press Start followed by Programs ForestGALES 2 5 ForestGALES When this is done the program will start and the main menu Figure 6 will load onto the screen Forest GALES has been designed as a complete Windows application Menus are easily accessible with the mouse in the top part of the main window or they can be accessed using pop up windows shortcut keys or speed buttons Operating modes Forest GALES can be used interactively in two operating modes e Single stand mode calculates the risk for one particular stand e Batch mode calculates the risk for a number of stands one after another There are three ways of making predictions within these modes e Predictions using field measurements calculates the risk of damage at a single point in time from stand characteristics defined by the user e Predictions using yield mo
33. at had occurred This confirmed users observations that Forest GALES 2 1 was pessimistic in its predictions of damage i e it was predicting more damage than actually occurred This coupled with new measurements of the gustiness of wind in forests has led to a reduction in the gust factor used in the software As a result the estimated critical wind speeds in Forest GALES 2 5 are higher and stands are now predicted to be more stable and at less at risk of damage This is the most significant change to the model output and largely over rides differences introduced by the other changes described below For example some thinnings that were restricted to sites with DAMS of 17 or below might now be possible on sites with DAMS up to 19 Note that this is only a general indication of the differences between ForestGALES 2 1 and Forest GALES 2 5 it is important that each site is assessed individually with the new version of Forest GALES QUINE C P and WHITE I M S 1994 Using the relationship between rate of tatter and topographic variables to predict site windiness in upland Britain Forestry 67 245 256 Change to inputs The resistance to overturning anchorage of a tree in Forest GALES 2 1 was calculated using information on soil type cultivation and drainage In Forest GALES 2 5 the effects of cultivation and drainage have been combined and replaced by rooting depth The grouping of soil types within Forest GALES 2 5 has also changed A So
34. ated research including tree health issues surveying and monitoring silviculture ecology and social science We also have expertise in hydrology land stability and urban greening and we lead in forestry adaptation and the contribution of forestry to climate change mitigation Forest Research s work informs the development and delivery of UK Government and devolved administration policies for sustainable management and protection of trees woods and forests www forestry gov uk forestresearch The Forestry Commission will consider all requests to make the content of publications available in alternative formats Please send any such requests to the Diversity Team at diversity forestry gsi gov uk or call 0300 067 5046 ForestGALES 2 5 Contents Introduction The Forest GALES software Background to the development of Forest GALES DAMS Detailed Aspect Method of Scoring Whats new in Forest GALES 2 5 Installing Forest GALES System requirements How to install Forest GALES Administration privileges in Windows 7 and 8 Help files Uninstalling Forest GALES Running the model for the first time How the model works What force would be needed to uproot or break the tree What wind speed would create the force required to damage the tree What is the probability of a damaging wind speed occurring Using Forest GALES Operating modes Selecting a mode and opening a query form Forest GALES query forms Navigating Forest GALES Getting help Pred
35. dThe AEP for a particular critical wind speed Windspeed is given by Critical wind speed By equating Equations 1 and 2 with Equation 5 it is possible to calculate the critical wind speed at canopy top for overturning and stem breakage U h crit over and U A erit break respectively in m s 13 u h ir over 1 pay In e d kD pGd on i 14 reos Morr et In Es kD 320G d 1 3 e a These equations have to be solved iteratively because porosity is a function of wind speed and therefore so are d and zo These critical wind speeds need to be converted to the corresponding wind speeds at 10 m above the zero plane displacement u d 70 qic in order to utilise meteorological data to calculate probabilities of occurrence and return periods 15 U d O crit u h crit where Usi is either U d 10 crit over OF U Ad 1O crit break Return period The return period for this critical wind speed u d 70 ci can be calculated from the Weibull distribution which describes well the wind speed distribution at individual locations in Britain Cook 1985 the Weibull shape parameter Weibull_K is relatively constant 1 85 and the scale parameter Weibull_A is related to the mean wind speed WSmean through the expression 16 WS mean Weibull_A T 1 1 1 85 Weibull_A 0 888 where T is the gamma function see Troen and Petersen 1989 The Weibull parameters are used to calculate the annual exceedance probability o
36. dels calculates the risk of damage at a single point in time from stand characteristics contained in yield models e Predictions through time calculates the risk of damage over a typical rotation from stand characteristics contained in yield models Selecting a mode and opening a query form Having started the program to select a particular mode left click on Mode at the top of the main menu A menu will appear Left click on the mode that you want and the menu will disappear and a form will appear automatically Alternatively a new form can be created using the shortcut buttons at the top of the main window The meaning of each shortcut button is indicated by a hint message that appears when the mouse is positioned over the button It is possible to have several copies of a query form open at the same time This may be useful if you wish to compare alternative scenarios Forest GALES query forms Forest GALES collects data from and writes results to query forms The exact layout of the form depends on the mode single stand or batch in which the model is being used and the type of prediction being made using field measurements using yield models through time Figure 8 shows the layout of the form for Single stand predictions using field measurements USING ForestGALES 11 12 ForestGALES 2 5 Figure 8 Query form for Single stand predictions using field measurements Single stand predictions using field measurements T
37. e By default the program will be installed into the directory C Program Files x86 Forest Research ForestGALES_ 2 5 However it can be placed elsewhere if required during the installation process The installation program will automatically place all the files where they are needed and add an option to run Forest GALES2 5 from the programs list Figure 1 or from the start screen in Windows 8 Figure 1 Programs list ForestGALES2 5 Eb ForestGALES2 5 Help ForestGALES2 5 4 Uninstall ForestGALES2 5 E q Back Search programs and files During installation you will be given information about copyright and the changes in Forest GALES2 5 in comparison with previous versions Method 2 if Method 1 does not work gt Unzip all the files required from the self extracting file ForestGALES25_Extract exe This file can be put anywhere on your hard disc The only difference from Option 1 above is that there is no dialog during extraction You must read Readme pdf or Readme txt for Users must agree to the PoresiG BES licence agreement during installation The licence agreement should be printed and kept for future reference and may be viewed or printed at any time from www forestry gov uk forestgales INSTALLING ForestGALES 3 6 ForestGALES 2 5 information on copyright and the changes in Forest GALES2 5 This method does not make a link to the programs list but you can add a shortcut to the desktop An e
38. e or good quality intensive drainage network Frequency of oscillation The number of sway cycles of the tree per second Fulcrum The position on the lee side of the tree where the root system pivots when the tree is bent by the wind hinge General yield class An index used in Britain expressing the potential stem volume productivity of even aged stands of trees in units of cubic metres per hectare per year based on an assessment of top height at a given stand age Gust A rapid increase in wind speed over a short period of time seconds rather than minutes Gust factor Ratio of the maximum turning moment to the mean turning moment on a tree from wind over the period of an hour Hinge See Fulcrum Leeward The side of the tree facing away from the wind Lever The distance between the point of action of a force and the fulcrum Modulus of elasticity A measure of stiffness Modulus of elasticity is the load that theoretically would be required to make a material double or halve in length were it to behave perfectly elastically In practice timber generally stops behaving elastically when its length changes by 1 and breaks when the change exceeds 2 Modulus of rupture The force per unit area that is required to break a material when a bending load is applied Moment Force multiplied by distance torque Overturning moment The force on the tree multiplied by the distance from where the force acts the centre of pressure to the fulc
39. e 4 7 Type the filename according to the format described on page 25 to 26 Note The filename must be enclosed in quotes e g SS201Z20 yld otherwise the file extension prn will be added resulting in a filename called something like SS20IZ20 yld prn 8 Press Save The new model will be accessible within Forest GALES when a new Predictions using yield models query form is opened Predictions through time Predictions through time allow the user to calculate the risk of damage to a stand over part or all of its rotation rather than at just a single age Figure 20 shows the predictions through time query form for single stands Making predictions for multiple stands is explained in the section on page 30 Batch mode section The main difference between predictions through time and predictions at a single point in time is that the results are displayed on a separate form when the model is run Also there is no option for modelling the effect of a new edge Figure 20 Query form for Single stand predictions through time g Single stand predictions through time ae Shand Choenctenstics Tree Chunciracitos Combos lard ID Porstadles Speri Saka Sin E Furi Sed Group E Bleyen mineral ans amp Pret Form Festina fi Shalkew Finntieg t Ef em l Sail and Mooting Help Tidi Chis 14 Thining rome Crann Tha Ph Irbrad spa ml Ge pen File El Save File Dams Th polaul Gm Reletence 7 Lalculsbun heman Apeh
40. e batch When Forest GALES is run a message appears in the bottom of the open window saying whether Weibull_A was entered directly or calculated using DAMS Batch Welbull mode There is also a new mode Batch Weibull mode When Research mode is selected an icon for this mode appears at the top of the Forest GALES window Figure 26 Click this to open the Batch Weibull window Figure 26 Batch Weibull mode icon File Mode DAMS Options Window Help A A This mode uses field measurements see the sections starting on page 15 and page 30 of User manual and Table 7 but Weibull_A and Weibull_K are entered individually for each stand in the Weibull Box Figure 27 DESF A Figure 27 Weibull box Weibull Weibull A EL a weibullK 1 85 E Table 7 Summary of derivation of Weibull parameters in each mode Single stand modes Read from parameter file Either calculated from DAMS or read field measurement from parameter file depending on yield model through time code in parameter file Batch modes Read from parameter file Either calculated from DAMS or read field measurement from parameter file depending on yield model through time code in parameter file Weibull_K and Weibull_A the same for all stands analysed in one batch Batch mode Weibull Entered separately for each stand in the batch field measurement irrespective of code in parameter file Long files The standard batch modes in Forest GALES 2 5 have a limi
41. e exception of files created while using the program Exceptions include saved exported data files and new yield models These may have to be manually deleted The DAMS folder can be deleted manually INSTALLING ForestGALES 7 8 ForestGALES 2 5 Running the model for the first time Start the program from the Windows Start button After the initial welcome screen you will be presented with the main menu window as shown in Figure 6 Choose Mode Single stand Prediction using field measurements and a new query form will appear as shown in Figure 7 The initial default values are as follows e Species to Sitka spruce e Soil group to Gleyed mineral soils B e Rooting to Shallow lt 80 cm e Current spacing to 2 8 m e Top height to 20 m e DBH to 20 cm e DAMS score of 15 Press the Run button and the Return period Wind damage risk status and Critical wind speeds for overturning and breakage will appear in the previously empty boxes at the bottom of the form Return periods will be 200 years for both overturning and breakage Change the top height to 22 m using the up arrow next to the top height edit box and press the Run button again The return periods will change to 13 years for breakage and 133 years for overturning You are running Forest GALES The various options available for the model are explained in later sections of this manual Figure 6 ForestGALES main menu Figure 7 Query form for Single stand
42. e guided by the windthrow hazard classification WHC system described in Forestry Commission Leaflet 85 Windthrow hazard classification This provided a method to zone forest areas of 500 ha or more by adding scores for windiness and soil together to estimate a hazard class Although the WHC provided a successful basis for comparing sites and guiding decisions on thinning it did not predict the timing or amount of damage with acceptable accuracy Furthermore it was not possible to test the influence of species choice or type of thinning For these reasons Forest GALES has now replaced the WHC as the recommended decision support tool for managing wind risk for forest management in Britain However it is possible to calculate WHC in Forest GALES so that users can make comparisons between the two methoas DAMS Detailed Aspect Method of Scoring The average windiness of a site is measured using the DAMS system DAMS is based on location elevation and topographic exposure and gives a good representation of both the average wind speed and the frequency of strong winds at a site Values of DAMS in Britain typically range from 10 sheltered to 24 exposed Small differences in DAMS can result in large differences in predictions of wind damage What s new in Forest GALES 2 5 Improved predictions A study of wind damage following a storm at a site in the west of Scotland in 2012 compared the damage predicted by ForestGALES and the actual damage th
43. e the canopy Gardiner et al 2000 Quine and Gardiner 2007 Du h k In where h is the average tree height m Zo is the aerodynamic roughness m and k 0 4 Von 2 4 M mean Z d z p Karman s constant This is then converted into a calculation of the maximum turning moment by multiplying by a gust factor G Du h k Pet where faw is a factor to account for the additional moment provided by the overhanging Mmax 2 fow d z 0G TECHNICAL APPENDIX 54 ForestGALES 2 5 displaced mass of the canopy This can be calculated directly using the tree bending equations described by Neild and Wood 1999 their Equation 7 if the force of the wind pu D the point of action of the wind d and the mass distribution with height in the tree are known A gust factor G is required because the maximum wind loading occurs during short term gusts of a few seconds but maximum wind loading is predicted from the mean hourly wind speed u h in order to match with standard climatological wind data G is the ratio between maximum and mean turning moment and is calculated as a function of the spacing to tree height ratio based on wind tunnel measurements Gardiner et al 1997 The original formula used by Gardiner et al 2000 was found to be unstable at low values of D h close spacing and was replaced by the following equation which gave a more robust fit to the data 6 G 2 1 D h 0 91 x h 1 0611
44. e what happens 3 Single stand predictions using yield models This example shows how to use yield models to provide input data for the model 1 Left click on Mode gt The Mode dialog box will open 2 Choose Single stand Predictions using yield models gt A new query form will open This form has a range of pre selected options However no value will be present in the Wind damage risk box For the purpose of this exercise make sure the default options are set to the following values Species Sitka spruce Soil group Gleyed mineral soil B Rooting Shallow lt 80 cm Yield class 14 Thinning regime Crown thinning Initial spacing 1 7 m Age 44 DAMS Score 15 Windfirm edge 3 Left click on Run gt This will give the probabilities of damage for a stand of YC 14 Sitka spruce planted at 1 7 m spacing with a crown thinning regime at an age of 44 The values in the Probabilities boxes will change and should become 200 years for Return period for overturning and 200 years for Return period for breakage The size and spacing of the modelled trees can be viewed using the Tree details button 4 Now change the age to 50 and left click on Run gt The values in the Probabilities boxes will change and should become 96 years for Return period for overturning and 83 years for Return period for breakage This indicates that the risk is increasing with stand age 5 Now left click on the down arrow to the right of Thinning regime gt A
45. edge This example shows how creating new edges affects the risk of damage i 2 es IS Start Forest GALES and open a query form for Single stands predictions using field measurements in the same way as the previous example Set the options to Species Sitka spruce Soil group Gleyed mineral soil B Rooting Shallow lt 80 cm Spacing 2 8 m Top height of stand 20 m Mean DBH 20 cm DAMS Score 15 Windfirm edge Left click on Run gt This will give the return periods for damage for the default parameters and no new edge Left click on the Brown edge button gt A black dot will appear on the button and the value for size of upwind gap will become black Change the Size of gap to 400 m Using the pre selected values left click on Run gt The values in the Probabilities boxes will change and should become 8 years for Return period for overturning and 3 years for Return period for breakage This indicates that the risk of damage is much greater if a new edge is present than if no new edge is present The Gap size box will also have changed to 188 m This is 10 x the mean tree height Gap widths greater than this have no additional effect on stability Now try changing the size of the gap to 20 m and left click on Run gt The values in the Probabilities boxes will change and should become 16 years for Return period for overturning and 5 years for Return period for breakage Again try changing other options to se
46. eight is used to raise a warning to the user for extrapolated values or where no data were available for the soil rooting depth combination Refer to the section starting on page 15 of the User guide for information on soil groupings and rooting depth Scaling parameter A scaling parameter has been included OTM scaling value to enable percentage changes to the anchorage coefficient to be applied without altering the actual values of the coefficients in the parameter file If the OTM scaling value is set at 100 this is equivalent to using the actual anchorage coefficient The structure of the species paramater file is shown on page 45 to 46 this must be adhered to e Within the species parameter file all comment lines begin with e At intervals after the a line number is given e g L8 These have been included to help ensure that the file format is correct They should correspond with the line numbers in the text editor User defined species Three user defined species can be used when working in Research mode The species parameter files for these are named U1Parameters txt U2Parameters txt and U3Parameters txt and are located in the directory SpeciesParamFiles Simply edit these to contain values for your own species the structure is identical to that described earlier In Research mode the Species drop down menu in the Tree characteristics box of all Forest GALES modes will show User defined species 1 User defined speci
47. ero plane displacement as functions of canopy height and area index Boundary Layer Meteorology 71 21 1 216 RUDNICKI M MITCHELL SJ and NOVAK M D 2004 Wind tunnel measurements of crown streamlining and drag relationships for three conifer species Canadian Journal of Forest Research 34 666 676 RUEL J C ACHIM A ESPINOZA R H CLOUTIER A and BROSSIER B 2010 Wood degradation after windthrow in a northern environment Forest Products Journal 60 200 206 THOM A S 1971 Momentum absorption by vegetation Quarterly Journal of the Royal Meteorological Society 97 414 428 TROEN I and PETERSEN E L 1989 European wind atlas Rise National Laboratory Denmark VOLLSINGER S MITCHELL SJ BYRNE K E NOVAK M D and RUDNICKI M 2005 Wind tunnel measurements of crown streamlining and drag relationships for several hardwood species Canadian Journal of Forest Research 35 1238 1249 REFERENCES a 58 ForestGALES 2 5 Wind damage is a major challenge for the management of forests in Britain and it has economic environmental and social consequences In some areas the threat of wind damage restricts silvicultural options and leads to the use of shortened rotations giving lower income from timber sales In order to minimise risk forest managers need information on the likely timing and magnitude of damage so that they are able to predict the level of risk and assess the implications of different management options
48. es 2 and User defined species 3 at the bottom of the species list This can be used to select your species If you make a batch input file for your user defined species the species codes should be entered as U1 U2 U3 If you are using these species for Predictions using yield models or Predictions through time ensure that you have made corresponding yield tables see User defined yield models on P27 of the User manual stored in the folder yldmodls XX where XX SUI OZ or Us Forest GALES 2 5Res Sitka spruce parameter file SS L3 Conversion Top height m to mean height m MeanHt Multiplier TopHt intercept Multiplier 1 0467 Intercept 2 1452 L8 CanopyBreadth m as function of DBH cm Equation form 1 linear Param1 DBH 100 param2 2 Power Param1 DBH Param2 O O AS O A Param3 10 1 11 4 Param 12 0 1346 13 Param2 14 0 6418 15 Param3 16 0 17 L17 CanopyDepth m as function of height m Mulitplier Height intercept m 18 Equation form 1 linear Param 1 Height param2 2 Exp Parar1 exp Param2 height 19 1 20 Param 21 0260 22 Param2 23 2 4682 24 L24 Stem Density 25 0390 26 Canopy Density LS 28 Modulus of rupture 29 3 4E7 30 L30 Knot factor gt ES 32 Modulus of elasticity Bee do ey 34 L34 Streamlining parameters 35 C 20 230 37 N 38 0 51 39 Root bending term RootBendK 40 0 0 A L41 Overturning Moment Multipliers 42
49. f the critical wind speed In Forest GALES 2 5 Standard mode Weibull_K is set at a constant value of 1 85 and Weibull_A is calculated from DAMS as follows Quine 2000 17 Weibull A a DAMS b For the forested areas where this relationship was parameterised values are a 0 4279 b 0 9626 TECHNICAL APPENDIX 56 ForestGALES 2 5 In the Research mode of Forest GALES 2 5 Weibull_A and Weibull_K can be entered directly by the user To calculate the annual exceedance probabilbity AEP we use a method developed by ESDU that links the Weibull distribution to the Fisher Tippet Type 1 extreme value distribution The AEP for a particular critical wind speed Windspeed is given by 18 AEP 1 exp exp 1 Windspeed 1 U Ua where from Quine 2000 19 U C U C1 Weibull K U_C2 Weibull K U_C3 Weibull K U_C4 20 U Weibull_A U_C The return period average number of years between damaging events is given by 1 AEP with U_C1 0 5903 U_C2 4 4345 U_C3 11 8633 U_C4 13 569 and U is taken as equal to 5 Quine 2000 References COOK Ny 1985 The designer s guide to wind loading of building structures Part 1 Background damage survey wind data and structural classification Butterworths London pp 371 GARDINER B A STACEY G R BELCHER R E and WOOD CJ 1997 Field and wind tunnel assessments of the implications of respacing and thinning on tree stability Forestry 70 2334292 GARDINER B
50. g DAMS score can be copied to the main form by pressing Apply or discarded by pressing Cancel Example 7 page 38 illustrates use of exact calculation for obtaining DAMS Figure 15 Exact calculation box Rough Guess Result WindZone 11 ViewMap DAMS 23 Elevation m 200 dl propos E Apply North 0 South North East 0 j SouthWest Help East 0 j West at j Y South East O North West X Cancel Upwind edge effect box The Upwind edge effect box Figure 16 is used to describe whether a new non wind firm edge has been created adjacent to the stand being modelled Brown edges i e edges that were originally not at the stand edge are often a place where wind damage starts If a new edge has been created then the Brown edge button should be pressed The size of the gap can then be altered The default value is O m The effect of a gap increases with gap width until the size equals 10 x mean tree height after which the effect remains at a maximum An example of changes to the upwind edge is shown on page 34 Example 2 Figure 16 Upwind edge effect box Upwind Edge Effect te Windir edge Brown edge Size of gap m o Controls box The Controls box Figure 17 allows the user to control Forest GALES The options are described below Figure 17 Controls box H Run lt Runs the model using the selected values Shortcut is Alt R ant For Prints the current quer
51. ick Soil and rooting help in the Stand characteristics box This will give a default rooting depth for each site Alternatively use the Soil and rooting help see Box 1 on page 18 Current spacing The average spacing between trees at the time of risk assessment It must be between 0 6 and 10 metres Current stocking The number of trees per hectare at the time of risk assessment The user has the choice between this option and the previous one Tree characteristics box The characteristics of the average tree of the stand are entered in the Tree characteristics box Figure 12 Figure 12 Tree characteristics box Tree Characteristics Species Sitka Spruce tal Top height of stand ri 20 0 l Mean DBH cr 20 0 3 The options that can be selected from the Tree characteristics box are Species The main species in the stand Options are Scots pine e Douglas fir e Corsican pine e Noble fir e Lodgepole pine e Grand fir e European larch e Sitka spruce e Japanese larch e Norway spruce e Hybrid larch e Western hemlock Top height Top height in metres of the stand being assessed This must be between 5 and 75 m Diameter at breast height dbh Mean diameter in cm of the stand being assessed This must be between 5 and 50 cm PREDICTIONS USING FIELD MEASUREMENTS 17 Box 1 Soil and rooting help Soil and rooting depth help is available in Forest GALES either by clicking on S
52. ictions using field measurements Stand characteristics box Tree characteristics box DAMS box Upwind edge effect box Controls box Wind damage risk box Predictions using yield models Stand characteristics box Tree characteristics box Other boxes User defined yield tables Predictions through time Stand characteristics box Tree characteristics box DAMS box Controls box User defined yield tables Viewing the results CON N OD WI UY WI NO BRO NB NO MO MO MO 11 17 17 11 13 14 15 15 17 20 21 21 22 23 23 24 24 25 27 Zi 24 21 Zi 28 28 ForestGALES 2 5 IV ForestGALES 2 5 Batch mode Creating batch input files Batch mode helper Batch mode query form Year of calculation Examples 1 Single stand predictions using field measurements getting started 2 Single stand predictions using field measurements the effect of a new edge 3 Single stand predictions using yield models 4 DAMS 5 DAMS rough guess 6 DAMS grid reference 7 DAMS calculate DAMS score Research mode Changing parameters Constants and limits input file Species parameter files User defined species Weibull parameters Batch Weibull mode Glossary Further reading and useful sources of information Technical appendix Critical turning moments for overturning and breakage Aerodynamic parameters Critical wind speed Return period References 30 S 31 al SL 33 233 34 ee 36 37 a 38 39
53. il and rooting helper is now available to help users choose the correct combination of soil and rooting for a given site As a result of these developments the inputs to ForestGALES 2 5 have changed However overall there is no substantial or systematic difference to the critical wind speed for overturning as a result of these changes and there is also less of a difference between soil types than there was in Forest GALES 2 1 Sites previously classed as having poor or good drainage will become slightly more and less stable respectively Crown size calculations The calculations of crown size within Forest GALES 2 5 have been revised and are now based on a much larger dataset than was previously available For most species this makes little difference For Scots pine and Corsican pine spuriously high values of critical wind speed no longer occur The larger dataset has produced substantially more robust calculations of crown size for western hemlock Douglas fir and lodgepole pine Normal and Research mode Forest GALES 2 5 runs in two modes The default Normal mode provides a standardised version that should give the majority of users all the facilities they require to make wind risk calculations and export results to Microsoft Word or Excel The alternative Research mode has added features that make the software more flexible for research users Species specific external parameter files make it easier to alter para
54. ils Shallow Cc 1 J J X Peaty mineral soils Deep GZ J x J Gleyed mineral soils Shallow B 1 J X X Freely draining mineral soils Deep A 2 X J Peaty mineral soils Shallow C 1 x x J Gleyed mineral soils Shallow B 1 X X X Freely draining mineral soils Shallow A 1 Freely draining mineral soils Shallow A X Gleyed mineral soils Shallow B J Peaty mineral soils Shallow Cc 1 X J Gleyed mineral soils Shallow B 1 X X Freely draining mineral soils Shallow A 1 PREDICTIONS USING FIELD MEASUREMENTS 1 20 ForestGALES 2 5 DAMS box DAMS is a measure of site windiness The greater the value the windier the site Only values between 5 and 32 the range of values found in Britain will be accepted by the model If the DAMS score for the site is known then it can be entered directly If it is not known then it can be estimated looked up or calculated by the program The DAMS box is displayed in Figure 13 The effect of changing the DAMS value is shown in Example 4 page 36 Figure 13 DAMS box DAMS Grid Reference C0 Calculation NH180150 Apply DAMS Score 15 3 Rough guess method In the DAMS box select Calculation then click the Apply button The calculation box will appear Selecting the Rough guess box Figure 14 will give the opportunity to estimate the DAMS score Select the options that best describe the site based on region within GB elevation shelter and aspect Press Apply to copy the resulting D
55. in the Batch mode helper are Add Alt A Adds the selected values to the input area of the query form Print Form Alt P Prints the current query form Help Alt H Starts the Help system Defaults Alt D Changes the saved default values saved to the ones included in the query form Close Alt C Closes both the helper and the query form Batch mode query form The characteristics of the stand are entered in the input area All data relating to a single stand are displayed on the same line After running the program the results of the model are displayed in the output area If the data have been saved then the filename will be displayed at the top of the output area The outputs vary slightly depending on the mode you are running in see Table 5 There is a slight difference when making predictions for Batch mode using yield models The year at which you wish to calculate the risk has to be specified on the query form rather than in the helper BATCH MODE z 32 ForestGALES 2 5 Table 5 Modes available for multiple stand predictions E Tos Predictions using field Return period for overturning wind damage risk status for measurements overturning return period for breakage wind damage risk status for breakage Predictions using yield models Model used current top height m current DBH m current spacing m return period for overturning wind damage risk status for overturning return period for breakage w
56. ind damage risk status for breakage Predictions through time Model used age to reach WDRS 1 to 6 for overturning age to reach WDRS 1 to 6 for breakage Double clicking on any of the input lines in this mode will open the graphics display window as for a single stand In this way it is possible to observe differences between the risk for all the stands entered as inputs Controls box The controls in the Batch mode query form are Calculate Risks Alt R Runs the model using the selected values Delete Row Alt E Deletes a row of data from the input area Open File Alt O Opens a previously saved query form Save Inputs Alt N Saves the input file for later use Save Outputs Alt U Save the output file so that it can be exported to another application Help Alt H Starts the Help system Excel Export Alt X Allows the user to export the tabular results to Excel Year of calculation When you are in the Predictions using yield models mode then the option is provided to modify the Year of calculation in the bottom right corner The default is the current year but any year in the past or future up to 2100 can be chosen If the age is less than the minimum in the yield table the model defaults to the minimum age If the age is beyond the maximum age in the yield tables the model defaults to the maximum age Examples 1 Single stand predictions using field measurements getting started Start Fore
57. ing moment Nm Max breakage moment Nm X X X CWS overturning at canopy top m s 3 i CWS breakage at canopy top m s i a Gustiness X X X X Edge factor X X X X Gust factor Edge factor Gustiness gt ZPD m X X X X ZO m X X X X Drag coefficient X X X X A Weibull X X X X K Weibull X X x X A Weibull method X X X Comments X X X X For Through time outputs in the table listed from Age downwards are output for each age in the selected yield table The values for Age to reach WDRS 1 6 apply to the whole rotation 1 CWS is critical wind speed at 10 m above zero plane displacement Canopy top is mean tree height RESEARCH MODE 49 50 ForestGALES 2 5 Glossary Anchorage The complex of mechanisms by which the root system and soil resist the wind forces on the stem and crown Brown edge An edge of a stand that was created by felling part or all of the adjacent crop rather than being a crop boundary since the time of planting Centre of pressure The average position in the crown of the tree where the total force of the wind can be said to act Coherent gusts Organised rotational motions in the air Vortices Critical wind speed Threshold hourly wind speed above which the average tree of a stand is expected to be overturned or snapped Critical height The top height of the stand at which damage was expected to start within the WHC system Cultivation The method of preparing the soil pri
58. lations have completed Specify a filename and path of your choice Note If you wish to use Save All for a given run of Forest GALES do so before running the model again as the default output file is automatically overwritten each time the program is run Table 8 Outputs saved using Save all button in Research mode DA ne Tech oh StandID Age Overturn WDRS1 Species X X X X Age Overturn WDRS2 x Yield class m ha yr X X Age Overturn WDRS3 x Thinning regime X X Age Overturn WDRS4 x Initial spacing m X X Age Overturn WDRS5 x Model used X X Age Overturn WDRS6 x Species file used X X X X Age Break WDRS1 X Soil group X X X X Age Break WDRS2 X Rooting depth X X X X Age Break WDRS3 X Spacing m X X X X Age Break WDRS4 X P Year X Age Break WDRS5 X Year of calc X Age Break WDRS6 X DAMS X X X Age yr X X Top height m X X X X DBH cm X X X X Mean vol m X Vol per ha m ha X Gap size m X X X CWS overturning m s x X X X Return period over yr X X X X WDRS overturning X X X X CWS breakage m s X X X x i en Weibull Through time Through time Return period breakage yr WDRS breakage X X X X CWS damage m s X X X X Return period damage yr Ie i WDRS damage X X X X Mode of damage X X X X Mean height m X X X X Canopy width m X X x X Canopy depth m X X X X Crown base m X X X X Stem wt kg X X X x Stem vol kg m X X X X Branch wt kg X X X X Branch vol kg m x X X X Max overturn
59. meters such as crown relationships or anchorage coefficients New species can also be added Weibull parameters describing the wind regime can be entered directly rather than by being calculated from DAMS A wide range of outputs can now be saved to a file ForestGALES 2 5 3 4 ForestGALES 2 5 Installing Forest GALES system requirements e Windows operating system Windows 3 to 8 e 30 MB of available hard disk space if DAMS scores not installed on hard disk or 535 MB for full installation The system requirements are minimal and Forest GALES makes no use of the Registry in order to reduce issues with Windows security In Windows 7 and 8 there may be some issues installing and running Forest GALES due to security settings see box below It is recommended to have Microsoft Excel and Word installed to help produce reports Results can be exported to Microsoft Excel Word or as ASCII text files A zipped directory containing DAMS values approximately 240 MB can be downloaded from the Forest GALES website www forestry gov uk forestgales and extracted to anywhere on your computer DAMS values are unchanged from earlier versions of Forest GALES so existing DAMS CDs can also be used How to Install Forest GALES Forest GALES can be installed in two ways depending on your computer s security settings Method 1 this should work on most computers gt Run the installation file called ForestGALES25_SetUp ex
60. o allow batch files of data i e multiple stands to be processed in addition to assessing the risk to stands one at a time This allows data for a whole forest property or coupe to be stored and calculated together In this mode data are read in from one file and output to a different file This can be very helpful if a large number of stands need to be assessed at the same time Those stands would not necessarily have to be linked to each other as the calculations are made independently The Batch mode can be used with each type of prediction The interface of Forest GALES in Batch mode is different from that used for individual stands and contains input and output areas as well as the control panel Figures 22 24 show the interface for each type of prediction Figure 22 Query form for Batch mode predictions using field measurements E Field measurements batch mode Ss In DANS Bas Sie Comins E Caine Boks Dhite Flue AE o A aaa E laa A ey HELPER Field measurements batch mode ela rro Shand Charschoiibcr Tiree Chansctensticw Control Sil Gidea E Died m end amp birt Fom Plot lr Shallow Poo e 3 cr Soll and Rooting Help Top height of manan a0 al E Onen Spargi 28 A Mean DOF fem EE z E He Curent Diesking Aha DAMS Und Edge Citect Y Dols E GrdiPeference amp Calculation Earn edge EE Apri DAMS Score 15 E Brown edge Size of pas im E al K Os Figure 23 Query form for Batch mode predicti
61. of the model is illustrated in Table 3 and is Line one a header to describe what is in each field Line two onwards fields separated by a single space to define Age years e Top height m e Stocking density trees ha e DBH cm e Basal area m ha e Mean tree volume m tree e Volume per hectare m ha In each case data refer to the main crop after thinning This is the format of the Forestry Commission yield models Table 3 Layout of a yield model for use in ForestGALES Age years Top height Trees ha Mean DBH Basalarea Mean tree Volume m cm m ha volume m ha m 7 4 2781 11 26 0 03 71 25 9 2 2300 13 32 0 06 90 30 10 9 1900 15 38 0 10 120 Naming user defined yield models The file should be saved as a text file with a file extension of yld If Forest GALES is to recognise the model then it must be named in a specific way This consists of an 8 character name 1 The first two characters indicate species these are shown in Table 4 2 The second two characters refer to the yield class 02 30 3 The third two characters refer to thinning regime and are shown in Table 4 4 The final two characters refer to initial spacing in metres x 10 Therefore 0 9 m spacing becomes 09 and 2 1 m spacing becomes 21 PREDICTIONS USING YIELD MODELS 25 26 ForestGALES 2 5 Table 4 Species and thinning codes for naming user defined yield models Sitka spruce Intermediate thinning no delay
62. oil and rooting help in the Stand characteristics box or by using the table shown opposite These can be used to identify which soil group and rooting depth to allocate to your site The numbered soil types listed in the table correspond to the Forestry Commission soil type classification set out in the Forestry Commission Field Guide The identification of soils for forest management Choose the numbered soil type in the table that best matches your site soil type Referring to the soil characteristics at the top answer the questions yes or no that apply to determine which soil group and default rooting depth to use in Forest GALES Cells shaded grey can be ignored Note that some of the numbered soil types match a soil group and default rooting depth with no questions The Rooting depth that is indicated by the helper is a default rooting depth that you can use if you have no information about rooting in the stand However if the rootable depth is known to be limited to lt 80 cm on a site a default deep rooting should be adjusted to shallow as appropriate Similarly if rooting depth is known to be gt 80 cm a default shallow rooting should be adjusted to deep In Single stand mode the Soil group and rooting depth are selected using the drop down menus in the Stand characteristics box If you are using Batch mode enter the appropriate codes in your input file see page 19 Soil and rooting help box Soil and Rooting Helpe
63. ons using yield models Yield models batch mode STE inputs Stand 0 Species y Clast Thinning za B Cause Baka E Diglete Rowe Sind Charachenahicy Tree Oharsckentticr 3 Conbrala Shared 1D FoeestaLES Sper Sika Spruce E Add Sed Group E Gleped waneral toli dd Diri Fam Fite fi Shales ostra ke 00 er Sai and Rooting Help Yield Chant 14 Thinning regina Cnn Tiircirg Bue brates epusciraj en hi t Planta yes 1970 El DAME Upvand Edge Ciest Th Desi 1 Grd Aeee C Casu rd edo Hiin p DAMS Semin 5 E O Benoe Sisa of gap ni p a X hos Figure 24 Query form for Batch mode predictions through time 5 Predictions through time batch mode elm A thail predican He mp i fm tng ah bina Contrasts f Cause Bak Ee Deise Haw re A A aa OO 5 k Se cd ys T HELPER Predictions through time batch mode o fa Stand Charactensicr Tree Charscteniior Contaly Stand ID F ceosiisAL Es Specs Sica Spe E Add Sod Group B Gileped mineral rods dd Piri Fom Frosting 1 Shallow Posting a BO cre S ana fisting Helo Yeda fi Thinang regens Excma Terr Bco h opercingy jn 7 AHS Ty Delme GidAeterence O Calculation en eph DAMS See 15 El K Lines Creating batch input tiles Input files can be created using the Batch mode helper window that appears in front of the query form when working in the Batch mode see Figures 22 24 Special codes are needed for some par
64. or to tree establishment This may have been done by many means such as ploughing mounding or producing turves Damping The processes by which oscillations are reduced in size and tend to stop Damping includes canopy clashing canopy drag through the air and frictional movement of stem fibres DAMS score Detailed Aspect Method of Scoring a system for scoring windiness derived from tatter flags and using representation of location and terrain to calculate a score DBH Diameter of a tree at 1 3 m above ground level Dominance The social status of a tree within a crop Five categories are usually defined dominant trees with a crown entirely within the canopy codominant trees with much of their crown in the canopy subdominant trees with their crowns generally below the canopy suppressed trees with small crowns entirely beneath the canopy which are gradually dying from lack of light and dead Drag area The surface area of the tree canopy and stem presented to the wind Drag area is reduced as wind speed increases due to streamlining of the tree Drag force The force on the tree caused by the pressure exerted by the wind on the crown wind loading Drainage A description of site wetness poor refers to a wet site where rooting is severely restricted by a shallow watertable due to local topography or failure of lack of installed drainage system good refers to better than average site due to topography e g shedding slop
65. r loj x Sod Clara a e S Select a soil from one of the 4 soil groups 4 E C or D Ref kennedy 2002 and FG User Guide Tor some soils Droen earths Ironpans Podzols end Mankers please also check whether the sod is gleyed or peaty A Freeda navel ede 8 Clete cle 2 Peyma D Deep pad Brown earth feeh draining Brown earth oleped Pa Juncus lor basin bogs i ronparn freet draining C rompan oleyed o Molinia for flushed blanket bogs C Podzol freely draining Podzol gered Podzal peaty C Caleareoue cod fraaly drainira Calesraous coil oleped O Ephaonum or Hat of raised boge C Ranker and skeletal brown C Rankers and skeletale gleyed C Rankers and Skeletals peaty a bial i Unflushed blanket bog Litoral soils C Surface water gley O Featy gley C Marmade soils C Groundwater gey C Eroded bog Soil Rooting Click Okay to accept 18 ForestGALES 2 5 Forestry Soil characteristics Entry for Stand characteristics box ate Indurated Iron pan Peaty Gleyed Brown Soil group Rooting euch plough pan broken depth hard pan Y Freely draining mineral soils Shallow A 1 X X Freely draining mineral soils Deep A 2 Gleyed mineral soils Shallow B 1 Y Freely draining mineral soils Shallow A 1 X Y J Peaty mineral soils Shallow Cc 1 X J X Peaty mineral soils Deep C 2 x x J Gleyed mineral soils Shallow B 1 X X X Freely draining mineral soils Deep A 2 J J J Peaty mineral so
66. rum plus the additional moment due to the weight of the over hanging crown Risk for a tree The probability in a particular year of the critical wind speed being exceeded see Vulnerability Risk status A measurement of the probability of the critical wind speed being exceeded in a particular year grouped into six categories Status 1 return period gt 100 years Status 2 return period 50 100 years Status 3 return period 33 50 years Status 4 return period 20 33 years Status 5 return period 10 20 years Status 6 return period lt 10 years Root architecture The appearance and structure of the root system particularly the number and arrangement in three dimensions of the thickest roots Rooting depth The average maximum depth of tree roots below the soil surface On many sites this is constrained by limiting soil conditions such as a water table induration or the underlying bedrock Rooting depth may be measured in a soil pit or estimated based on soil type and conditions Spacing Current The average spacing between trees at the time of risk assessment Spacing Initial The average spacing between trees at the time of planting Stocking The number of trees per hectare at the time of risk assessment Terminal height The top height of a stand at which wind damage was expected to reach a level necessitating clearance Thinning The removal of a proportion of the tree crop for silvicultural or economic reasons Forest GALES can extrac
67. st GALES _ Left click on Mode NO gt The Mode dialog box will open OU Choose Single stand Predictions using field measurements gt A new query form will open This form has a range of pre selected options However no value will be present in the Wind damage risk box For the purpose of this exercise make sure the default options are set to the following values Species Sitka spruce Soil group Gleyed mineral soil B Rooting Shallow lt 80 cm Spacing 2 8 m Top height of stand 20 m Mean DBH 20 cm DAMS Score 15 Windfirm edge IS _ Left click on Run gt Values of 200 years will appear in the Wind damage risk box for the Return period for both overturning and breakage UI Left click on the up button to the right of the Mean DBH box gt The DBH will increase by 0 1 cm per click ON Keep changing the DBH in this way until a value of 22 cm appears in the box gt Change Top height until it reads 22 m po Change Current spacing until it reads 3 5 m Left click on Run NO gt The values in the Wind damage risk boxes will change to 30 years for Return period for overturning and 8 years for Return period for breakage This indicates that the risk of damage changes rapidly with changes in DBH height ana spacing Other parameters can be changed in a similar way EXAMPLES 23 34 ForestGALES 2 5 2 Single stand predictions using field measurements the effect of a new
68. t available and in these cases assumptions are made to allow data to be extrapolated When this happens a warning message box will appear What wind speed would create the force required to damage the tree In Forest GALES the wind loading on trees is calculated from the drag the forest exerts on the flow above the canopy The drag is a function of the wind speed and the aerodynamic roughness of the canopy which is dependent on the crown size and the area of ground occupied by each tree Crown size is modelled using regressions based on the height and diameter of the tree From a knowledge of the average wind loading on each tree and the resistance to breakage and overturning the wind speed that would just cause the tree to overturn or break is calculated This includes calculating the extra force due to the overhanging weight of the crown and stem as the tree bends What is the probability of a damaging wind speed occurring Having calculated the wind speed required to damage the tree the probability of such a wind speed is estimated HOW THE MODEL WORKS 9 10 ForestGALES 2 5 The average windiness of the site is measured using the DAMS system which is based on location elevation and exposure However average winds are unlikely to damage the tree and the risk of extreme winds that are sufficiently strong to cause damage must be derived from DAMS using a Weibull distribution This distribution is extremely sensitive
69. t data from yield models categorised according to thinning regime and initial spacing The regimes used in the yield models are non thinning no trees actively removed though some may die naturally intermediate thinning removal of trees from throughout the crop with the smaller trees being preferentially removed line thinning removal of trees in straight lines and crown thinning removal of trees that are competing with the crowns of the highest quality trees Models have also been produced for delayed thinnings Top height The average height of the 100 trees of largest diameter per hectare usually measured as the average height of the largest diameter trees in a sample of 0 01 ha plots Topex A measure of exposure based on the sum of the angles to the horizon in eight compass directions Turbulence The random variations in wind speed and direction Vortices See Coherent gusts Vulnerability The threshold wind speed required to blow over a particular tree on a particular site WHC See Windthrow hazard classification Wind loading See Drag force Windthrow hazard classification A method to zone forest areas of 500 ha or more by adding classification scores for windiness and soil together to estimate a hazard class Each class was associated with a critical height and a terminal height Windward The side of the tree facing towards the wind Wind zone A range of windiness categories for the whole of Britain The higher the wind zone the
70. t of 32994 lines of data While this is sufficient for most purposes on occasion a longer file might be needed The Batch Weibull mode includes a feature allowing files of unlimited length to be read in Files in Batch Weibull mode are of the type bmw For guidance of how to easily create a batch input file refer to Creating batch input files on page 31 Open Batch Weibull mode Select the Field measurements Weibull batch mode window Click the Run long file button or Alt L Select the file and click Open RESEARCH MODE 47 48 ForestGALES 2 5 Forest GALES will then process the selected file Outputs are automatically saved as a csv file with the same name and in the same directory as the input file Outputs In addition to the basic outputs saved in Normal mode of Forest GALES 2 5 Save Outputs button See Table 5 in Research mode there is a Save All which saves inputs and basic and detailed outputs Table 8 In Batch mode using field measurements Batch mode using yield models and Batch mode using Weibull parameters Save All saves information for all stands included in the batch For predictions through time Save All is available in Single stand mode and in Batch mode when you double click a single row of data to view outputs for an individual stand Clicking Save All at this point will save information for the selected stand The outputs saved are shown in Table 6 To use Save All click on the button when calcu
71. ure 4 Default file selection File Mode DAMS Options Window la TENY Help Ctrl 4 H A iw A iA About Cols i Default Help File i forestgales25 help_manual hlp ha i ae forestyales25_help_marmwal chrm Uninstalling Forest GALES To uninstall the program 1 Press Start or click the PC settings button in Windows 8 2 Choose Control panel 3 Choose Programs Uninstall a program or put Control Panel Programs Programs and Features into Windows Explorer 4 Select ForestGALES2 5 from the list of programs Figure 5 5 Left click on Uninstall in the banner above the list of programs Figure 5 Uninstall r a F Cantal Panel F Programs b Programms and Features Control Panel Horne 5 Uninstall or change program View mslalled updates Ter ur nstall a pgearce select it frorn thee fist and ther click Uninstall Charge ar Repair Tum Windows features on or oft Organise Uninstall Change Repair Mame i Publisher Installed Om Size Version a Canon Utilities Solution Menu 144112013 Fal tnatote AL lhomson Researchsott Can LSM 1200324 dee Forest Yield 1 0 Forestry Comrrassaon Research MR 3256 MA 10 64 Al ForestGALES 2 5 Forest Research Google Chrome Google Inc 31 03 2015 40 403 137 G Forest Research Product version 2 5 5 Support fink hiper forestry go uk mM GINA Help fink http ww forest Os Size 8 7 ME This will remove all the components and data files of Forest GALES2 5 with th
72. ure that the file is in the correct location and click Run again The format of the two types of parameter files are shown within this document In addition Read only versions of example files are provided ExampleFGParameters txt and ExampleSpeciesParameters txt A Restore defaults option is available which will return all values in all external parameters files to the installation values Click Options Restore defaults or Ctrl shift Z Constants and limits input file The file containing constants and model limits is called FGParameters txt It is held in the root directory of Forest GALES_2 5 i e ForestGALES_2 5 FGParameters txt and must not be moved from here The parameters held in this parameter file are Physical constants e Snow density kg m e Von Karman constant e Air density kg m e Acceleration due to gravity m s Model limits e Number of tree heights from edge assumed to be in forest e Size of gap regarded as infinite in tree heights e Limit defining resolution of ForestGALES model e Multiplier defining number of sections in each metre length of trunk e g multiplier 2 to have 0 5 m sections multiplier 0 5 to have 2 m sections more sections means more accuracy but slower computation time Aerodynamic parameters e Element drag coefficient CR used to calculate zero plane displacement e Surface drag coefficient CS used to calculate zero plane displacement e Constant CW
73. used within Forest GALES Changing parameters In earlier versions of Forest GALES parameters were hard to change because they were embedded in the code Forest GALES 2 5 has external parameter files enabling users to easily alter parameters One file contains universal constants physical and aerodynamic parameters A separate set of files one for each species contain parameters and variables that differ according to species These files can be edited using any text editor However it is easiest to use a text editor that enables Forest GALES to access the file while it is open within the editor so the file need not be closed each time the program is run RESEARCH MODE 39 40 ForestGALES 2 5 These files are read each time Forest GALES is run i e Run or Calculate risks button pressed This means that they can be altered saved and the model rerun without needing to close ForestGALES between runs The name file location with respect to the executable Forest GALES file and file formatting are hardwired into Forest GALES 2 5 If a parameter file is not found or is formatted incorrectly an error message will appear and the program will do no calculations In Batch mode no calculations will be done for the affected input row and all subsequent rows The program does not need to be closed while the problem is resolved For example if the message File FGParameters txt not found appears after clicking Run click OK then ens
74. when wanting predictions made at a single point in the future Figure 19 shows the predictions using yield models query form for single stands Making predictions for multiple stands is explained in the Batch mode section An example of this type of prediction is shown on page 35 Example 3 A selection of yield tables is distributed with Forest GALES and is stored in the directory Xyldmdls To select a yield model choose the species then select the yield class thinning regime and initial stocking that apply Only the yield models which are available can be selected from the program It is however possible to create new yield models which can be used as input for Forest GALES This is described on pages 25 to 26 Figure 19 Query form for Single stand predictions using yield models oh Single stand predictions using Yield Models rca E Stand Cheeattensbcr Tres Chslscienttco Control ElandiD fas dGALES Species Sitka Speuce Sed Cr IB Gleped Sirera codo a Pret Form Ficat T Shaka Rob El an EJ Feron Sail ard Aentieg Heip Wed Clases m gt Thinning rege Crown Thinning Heb Initial escia it 17 x G Dren Fie Planting pear ii a E Aga u Z Tee eta Ga Sieve Fin DAMS Upward dos Elec ti Delauk m Ord Relevance 77 Cauda e Aa ela RATEOISO Apph DAMS Sewe g C Beomedgn Size ot geo im E 2 X One wird Damnga Bick ae Hasian ped Wirel Damage Hick Shah Liberal vere speed Cobcal eared speed at h CER LE
75. with species codes U1 U2 and U3 The species parameter file includes e 2 characters species code e g SS for Sitka spruce When Save All is clicked this code is written to the output file to provide a check that the correct species parameter file has been used Parameters for equations e Multiplier and intercept for linear conversion from Top height m to Mean height m MeanHt Multiplier TopHt intercept e Parameters to calculate Canopy breadth m as function of DBH cm and code for form of equation Code 1 Linear Paraml DBH 100 Param2 set param3 0 Code 2 Power Paraml DBH Param2 Param3 e Parameters to calculate Canopy depth m as function of height m and code for form of equation Code 1 Linear Paraml Height Param2 Code 2 Exponential Paraml exp Param2 height Set values e Stem density kg m e Canopy density kg m e Modulus of rupture e Knot factor e Modulus of elasticity e Streamlining parameters C N e Root bending term RootBendK See Equation 12 in Technical appendix Normally set 0 RESEARCH MODE 43 LA ForestGALES 2 5 Overturning moment calculation Anchorage coefficients For each of the four soil groups A B C D there are three anchorage coefficients one for each rooting depth shallow deep and one user defined See Equation 1 in Technical appendix Maximum stem weight kg For each soil rooting depth combination the maximum stem w
76. xample shortcut ForestGALES25 Ink is provided in the folder ForestGALES_2 5 Templates which links to ForestGALES exe extracted to the desktop The shortcut must be placed on the desktop and its target properties edited to match with the particular user and extraction location of Forest GALES2 5 Figure 2 Figure 2 Shortcut settings Go ForestGALES25 exe Properties ln Security Dotala Previous Versions General shortcut Compatibility cA Fora AI F525 ewe a Target type Anplcathan Target location Din Target arch ForeshGALES 2 5 Bin ForestGALES exe Start in C Program Files c26 Foreet Rersarch ForsetG Shotcut key Mone Run Normal window Comment Open File Location Change Icon Advanced Cancel Apply Administration privileges in Windows 7 and 8 The level of security has increased in Windows 7 and 8 compared with previous versions This means that there can be problems in installing running or saving files if Windows requires administrator rights The installation program described in Method 1 above has been set up to try to minimise these problems and give the user control over all the files in the installation file space However if you have any problems with lack of privileges you have three options 1 Install the program to an area of the hard disc where you know you have read write and execute privileges 2 Install the self extracting version Method 2
77. y form Shortcut is Alt P Creates a report that contains all the information on the form The report can be printed or saved for later use Shortcut is Alt T Help lt Starts the Help system Shortcut is Alt H C Open File lt Opens a previously saved query form Shortcut is Alt O Save File lt Saves a query form so that it can be reused at a later date Shortcut is Alt S Th Defaults Changes the saved default values to the ones included in the query form Shortcut is Alt D Close lt Closes the current query form Shortcut is Alt C PREDICTIONS USING FIELD MEASUREMENTS 21 22 ForestGALES 2 5 Wind damage risk box Model outputs are displayed in this box Figure 18 Figure 18 Wind damage risk box Wind Damage Fisk Retum period wind Damage Risk Satus Critical wind speed OVERTURNING hS sf TO 274 m s 123456 BREAKAGE 83 ma pr wee Critical wind speed The critical wind speeds i e the lowest wind speeds that will cause overturning or breakage are presented By default these are presented in m s Wind speed units can be changed in the Options menu Return period The average length in years between wind speeds exceeding the critical wind speed occurring at the site This is the average interval between gales that will damage the site The statistical nature of the wind climate means that strong winds with long return periods i e gt
78. ype with the lower critical wind speed Forest GALES also allows the user to test the impact of standard thinnings or alternative thinnings defined by the user Forest GALES is the recommended tool for testing the impact of thinning in operational guidance for Forestry Commission staff Upaates and further information For latest updates and on line version of this manual go to www forestry gov uk forestgales ForestGALES 2 5 2 ForestGALES 2 5 Background to the development of ForestGALES Forest GALES is based on research conducted by the Forestry Commission and Forest Research over the past 50 years Version 2 5 represents over a decade of development since Version 1 0 was first published in 2000 and it contains significant improvements from Version 2 1 published in 2006 For example there have been improvements in the way the model simulates the gustiness of the wind the description of tree crown characteristics the classification of soil and rooting and the representation of the wind climate In particular there has now been validation of the model against wind damage in Cowal and Trossachs Forest District following a storm in January 2012 Work is currently underway on prototype models that calculate the risk to every individual tree within a stand rather than an average tree and work with mixed structure and species stands Prior to the availability ofthe ForestGALES software strategies for minimising wind damage wer

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