SILVICULTURAL STRATEGIES FOR PREDICTING DAMAGE TO FORESTS FROM WIND

SILVICULTURAL STRATEGIES FOR PREDICTING DAMAGE TO FORESTS FROM WIND, FIRE AND SNOW: INTEGRATING TREE, SITE AND STAND PROPERTIES WITH GEOGRAPHICAL INFORMATION SYSTEMS AND REGIONAL ENVIRONMENTAL MODELS TO EVALUATE OPTIONS FOR FOREST MANAGEMENT

CONTRACT NUMBER - AIR3-CT94/2392

Participants:

P01 Faculty of Forestry, University of Joensuu, Joensuu, Finland

P02 Department of Forestry, The University of Aberdeen, Aberdeen, UK

P03 Centro Nacional de Informacao Geografica, Lisbon, Portugal

P04 Forestry Commission, Northern Research Station, UK

P05 Macaulay Land Use Research Institute, Aberdeen, UK

P06 Direcção Geral das Florestas, Ministério da Agricultura, Lisbon, Portugal

P07 Faculty of Forestry, The Swedish University of Agricultural Sciences, Umeå, Sweden

P08 School of Engineering, University College, Galway, Ireland

Period of report: January 1995 - June 1997

SUMMARY

WIND, FIRE AND SNOW: INTEGRATING TREE, SITE AND STAND PROPERTIES WITH GEOGRAPHICAL INFORMATION SYSTEMS AND REGIONAL ENVIRONMENTAL MODELS TO EVALUATE OPTIONS FOR FOREST MANAGEMENT

Participants

P01 Faculty of Forestry, University of Joensuu, Joensuu, Finland

P02 Department of Forestry, The University of Aberdeen, Aberdeen, UK

P03 Centro Nacional de Informacao Geografica, Lisbon, Portugal

P04 The Forestry Authority, Northern Research Station, UK

P05 Macaulay Land Use Research Institute, Aberdeen, UK

P06 Instituto Florestal, Ministerio da Agricultura, Lisbon, Portugal

P07 Faculty of Forestry, The Swedish University of Agricultural Sciences, Umeå, Sweden

P08 School of Engineering, University College, Galway, Ireland

Scientific objectives

This project aims at producing generic models which use the factors common to wind, snow and fire damage; to underpin those models with an understanding of the forces and site factors acting on single trees or the fuel hazard risks associated with site factors to produce risk assessments to forestry to minor or catastrophic damage; to test these models as a way to derive long term strategies of silvicultural methods for managing forests against wind, snow and fire damage, that optimize wood production while appraised of the risk of forest damage. This project utilizes methodology where models for estimating the overturning and breakage due to wind and snow load and models to estimate fuel are integrated with the data bases for properties of climate and vegetation controlling the wind, snow and fire damages to forests in order to optimize wood production considering the risks to forests.

The progress within the period of report

Task 1. Project Planning

Sub-task 1.1. Planning Design

The planning report has been undergoing continual update throughout the period of the Project. However, the complete report is now available on the web and P05 ftp sites. Making the document "live" in this way has meant it is continuously available for update and perusal by all participants, without the need for temporally discrete stages of update and dissemination which leaves participants guessing as to the most recent updates. This is particularly crucial for such a large and geographically distributed group who are working in close collaboration. Metamodel and metadata forms, as detailed in Task 6 are also available on the web, and participants have been actively completing these forms in remote locations to provide instantly available documentation to the rest of the group. This has greatly enhanced the planning and management of the project, and facilitated a process of documentation for models and data which can be used as input to Task 6, and to increase inter-participant understanding of other participant's work which is vital when models developed by one participant are being tested on data supplied by another.

Sub-task 1.2. Scale

The planning report allowed the issues of scale to be identified through a comprehensive review of the scales at which it is planned that the different models should operate, and the resolution of the information of the data available. The results of this feed into the integration and scale assessment issues in Task 6.

Task 2. Quantification of Component Factors Controlling Snow, Wind and Fire Damage

Sub-task 2.1. Wood Property Factors Controlling Wind Damage

Two severely wind damaged Sitka spruce stands have been studied in 1995 and wood samples have been taken from a total of 72 of snapped, over-turned, and undamaged trees by P02. In 1996 two further badly wind/snow damaged sites, one Sitka spruce, the other Scots pine, have been sampled. Laboratory analysis of all these samples has now been completed and results have been obtained for ring width, density, and compression wood characteristics of wind/snow damaged and undamaged trees. Based on small clear wood samples removed from the outer part of the stems of Sitka spruce and Scots pine trees, no link was found between type of damage and modulus of rupture (MOR). A link has, on the other hand, been found between modulus of elasticity (MOE) and damage type, with the MOE of wood samples taken from snapped trees being significantly lower than for samples taken from undamaged trees in both Sitka spruce and Scots pine. The cause of this link between stiffness and damage type is unclear. Futhermore, the length of the clear bole (i.e. stem without living branches) and length of living crown was not found to have any clear relationship with damage type in each forest sampled. Spruce trees with a large crown area, however, appeared to have a reduced risk of damage. These trees may be the local dominants that have developed larger crowns from an early age and thus have been influenced by the wind for a long period.

Sub-task 2.2. Wood Property Factors Controlling Snow Damage

Critical tree parameters controlling snow and wind damage for a sub-sample of sample plots from the existing Swedish National Forest Inventory (NFI) was determined by P07 and a data base from the same sub-samples made available to P02. Logistic models developed for Scots pine showed that it is possible to predict future damage from snow and wind by using single tree characteristics from the thickest tree at a sample plot as indicators of site risk (see Valinger and Fridman, 1997). For Scots pine the predicted damage probability to a site was found to be higher if the largest, i.e. thickest, tree has a tapered stem form, i.e. low ratio of height/diameter at breast height. Although the overall damage frequency for Västerbotten was low, the preliminary logistic model developed show that it is possible to predict future damage from snow and wind by using single tree characteristics as indicators of site risk.

The additional models were also developed using tree characteristics for Norway spruce, Scots pine, and birch to predict the susceptibility to damage from snow and wind in the whole country of Sweden. In this work, all NFI permanent sample plots dominated (>70% of basal area) by Norway spruce, Scots pine, and birch have been used and tree charcteristics as height, diameters at stump height, and breast height have been used for models assessing future risk of snow and wind damage. The data base from the sub-samples used for hypothesis testing is available at P07 ftp-site. All information from this sub-task have been delivered for Task 3, 4, 5, and 6.

Sub-task 2.3. Tree and Soil Factors Controlling Wind Damage

The extensive tree pulling database of total number of over 1800 trees has been constructed by P04, and linked to this work P01 has constructed Finnish tree pulling database of 115 trees of Scots pine, Norway spruce and birch spp on podzolic soils (see Peltola et al. 1997d). Regressions have also been calculated between various tree and site characteristics and critical turning moments needed to cause uprooting of single trees or stem breakage based on these tree pulling databases by P01 and P04 for determination of values for the critical parameters required to support the development of the models to be done in Subtasks 3.1 and 3.3 (see Granander 1996; Peltola et al. 1997d). P01 has also made wind and tree swaying measurements at the edge of a Scots pine stand and within the stand especially two tree heights from the edge prior and after two thinnings (see Peltola 1995, 1996a, Hassinen et al. 1997). To date, mean wind profiles and stem bending of trees at the stand edge and within the stand have been analysed in a Scots pine stand having stand density of 2700, 1500 and 1100 stems/ha, i.e. prior and after first two thinnings (see Peltola 1995, 1996a, Hassinen et al. 1997). The wind and tree swaying experiment carried out by P01 have provided further information on mean windspeed profiles and tree stem bending for varying stand densities, and have given further information for subsequent modelling work and models testing to be carried out in Subtasks 3.1 and 3.3.

Within this sub-task 2.3, P08 has also developed a new video analysis technique for estimation of the overturning moments experienced by a tree during a storm event. P08 has currently carried out a field testing programme on test sites with test trees, i.e. on three site preparations on surface water gley in Ireland. To date some preliminary results are already available on these field testings of both monotonic and dynamic loading tests of trees on the various site preparations as well as on a long term tensiometry study of the characteristics of the three site preparations. Efforts to estimate a factor to relate the ultimate overturning moments found from destructive pulling tests to those which results in trees being windthrown have also been ongoing. Dissemination of research findings is currently under work in this Sub-task 2.3 (see Granander 1996; Peltola 1995, 1996a, Peltola et al. 1997f, Hassinen et al. 1997).

Sub-task 2.4. Vegetation Characteristics Controlling Fire Damage

Sets of spectral and biometric data have been collected in two field campaigns in 1995 and 1996 for pine stands and shrublands for supporting the regional classification of fuel types using satellite imagery. In addition, a controlled experiment to develop methodologies for unmixing narrow band-spectra of tree-soil-understorey composites has been performed.

Task 3. Tree-level Models to Predict Circumstances for Damage

Sub-task 3.1. Empirical models of breakage and overturning of single tree by wind

P04 has developed and made available an empirical model predicting the wind speeds required to break or overturn trees. The model is based on a knowledge of the tree species, tree height, tree stem diameter, inter-tree spacing, soil type, cultivation and drainage treatment, distance from forest edge and size of upwind gap. It makes use of the fundamental information on wood properties and resistance to overturning obtained in Sub-tasks 2.1, 2.2, and 2.3 (see Gardiner and Peltola 1997). The model can be run in interactive or batch mode and can be integrated with a GIS.

Sub-task 3.2. Empirical models of breakage of single tree by snow

The logistic models developed under Sub-task 2.2 have been further developed by P07, not only for separate species, but also for different sites and soil types. To apply logistic statistical analysis technique the existing permanent sample plots Swedish National Forest Inventory (NFI) data base have been used (so that the progress of damage can be monitored), i.e. data separated according to species, site type, and management treatment. Data inputs used are tree species, various tree, stand and site characteristics (i.e. height, diameters at stump height, breast height, and at 5m, stand density, standing volume, co-ordinate of sample plot, height above sea level, etc.). According to the preliminary work on Scots pine, it was indicated that damage from snow and wind to a site can also be predicted using only the stand variables; stand age and stand volume density (P=0.0001). When using site variables only, the predictability using the variables northern co-ordinates in the Swedish system of co-ordinates, and height above sea level also was high (P=0.0001). When combining tree-, stand-, and site data the fitness of the developed model did not improve as much as expected (P=0.0001) (Fridman and Valinger, 1997). To date, models are available for the whole country using NFI data on tree, stand, and site characteristics for Norway spruce, Scots pine, and birch sites.

Sub-task 3.3. Mechanistic model for wind and snow damage of single tree

The mechanistic model of wind and snow damage of single trees (HWIND) developed under Subtask 3.3 by P01 will be capable of calculating the mean windspeed to uproot or break a tree along with critical snow loading for various distances from the stand edge at the margins of clear-felled areas (upwind gaps of various sizes). To date the model covers especially Scots pine, Norway spruce and birch sp. growing on podzolic soils (moraine formation) in Finnish conditions. However, other tree species and soil types (for various geographical locations) can be used by changing the controlling parameters and equations for species (and soils). The HWIND can be run using PC (Windows95) but also UNIX-version is available.

To date, HWINDmodel testing/improvement has been completed based on Finnish tree pulling database constructed in Subtask 2.3 for Scots pine, Norway spruce and birch spp, and based on measurements of windspeed and tree movement prior and after thinnings (from Sub-task 2.3). Results of sensitivity tests are also available for HWIND-model by P01 to determine the critical parameters involved and the reliability that can be placed on the critical windspeed predictions.

HWINDmodel predictions by P01 have also been compared with the predictions based on empirical wind damage model developed by P04 in Subtask 3.1 to improve the methods for estimating critical windspeed (see Gardiner and Peltola 1996, 1997). In addition, a literature review has been finished on the factors affecting the snow damage of trees to support the mechanistic model development and its validation within Subtask 3.3, in a cooperation by P01, P04 and P05 (see Nykänen et al. 1997). Dissimination of research findings within this Subtask 3.3 is currently under work (Gardiner and Peltola 1996, 1997; Nykänen et al. 1997; Peltola 1995, 1996c, 1996d; Peltola and Kellomäki, 1997; Peltola et al. 1995, 1996, 1997a, 1997b, 1997c; Päätalo et al. 1997; see also Metamodel form for HWIND, 1996).

Sub-task 3.4. Leaf area index (LAI) estimation

P03 has eveloped two indirect methods to estimate the Leaf Area Index (LAI) of maritime pine stands which enable a precise evaluation of this parameter by ground measurements, and support the image processing developed in sub-task 5.4. One model is tree based, and predicts single tree leaf area using as independent variables three, easy to measure, standard dendrometic parameters. The other model evaluates LAI using measurements of canopy PAR (Photosynthetically Active Radiation) transmittance obtained with a portable ceptometer. For the development of the models, 30 individual trees and 25 stand plots were measured during two field campaigns held in 1995 and 1996. This task had the collaboration of P06, who provided logistic and field support. The work planned for this task has been completed and the predefined objectives have been fully achieved.

Task 4. Defining stand-level Variability to Permit Application of Tree-level Models

Sub-task 4.1. Wind Flow across and within Stands Using Airflow Models

P01 has calculated the wind loading on individual Scots pines as a function to distance from stand edge, stand density (in terms of leaf area index) and tree height and width of upwind gaps using airflow model developed by Miller at the University of Connecticut (see Peltola 1996b). In addition, because there has been delay (and still exists) in getting the more sophisticated airflow modelling efforts available by P04, empirical relationships have been derived from existing wind tunnel studies to relate mean and extreme wind loading to distance from stand edge, stand density and tree height. These empirical relationships derived from existing wind tunnel studies by P04, and used in the HWIND-model (Sub-task 3.3) has allowed progress within this Sub-task in simulation of the wind loading and critical windspeed to uprooting and stem breakage of individual Scots pines, Norway spruces and birch spp as a function to distance from stand edge, stand density (stems/ha) and tree height (see Gardiner and Peltola 1997; Peltola et al. 1997c).

Sub-task 4.2. Variation in Measured Tree Characteristics within Stands Using Various Methods Including Remote Sensing

This Sub-task task involves an integrated approach to investigating the effects of variability by using existing data sets, making new measurements and developing mathematical models. Efforts have been made to identify suitable data sets for analysis, testing methodologies for measuring stand variability, investigating the importance of variability in stand growth model. Good progress has been made particularly with regard to the remote sensing aspects.

Within this sub-task, also the logistic models (using tree characteristics) developed by P07 in Sub-tasks 2.2 and 3.2 have been used to calculate probability of damage from snow and wind for the site were each of the NFI permanent sample plots are situated. The probabilities have been mapped for the whole country during spring 1997. The resulting probabilities of damage for the whole country show a higher risk at Norway spruce sites than for sites dominated by the other native species. The risk is higher in southern Sweden than in the north.

In addition, digital elevation models have also been been derived by P05 for all or part of the Cwm Berwyn study forest for each of the following dates: 1957, 1977, 1992 and 1995. Evidence of changes in forest management and areas of damage caused by wind are being measured and accuracy estimates being made. Different measures of stand variability are curren in the forest canopy reflecting landform and forest management. In addition, the position of pockets of damage within the forest stand and with respect to the edge of the stand, in eight different directions, have been measured and are being studied to check for any relationship between damage and position within the stand. There has been a delay within this work because of a delay in obtaining the original aerial photographs and the processing requirements.

Sub-task 4.3. Plot-level Mixture Modelling

Spectral mixture models, that take into account non-linearity, are under development for understory characterization. So far, factor analysis has been used to identify the shrubs that can be spectrally discriminated from the pine canopy and the ones that can not.

Sub-task 4.4. Preparation of Knowledge Base for Fuel Hazard Mapping

The preparation of the Knowledge Based for fuel models mapping involved the collection of field data points and calculation of several environmental variables within the GIS database. The field work of fuel model point sampling was initiated in 1996 and 45 points have been collected and processed so far. For each point, extraction of geographical environmental data has been performed and organised in a relational database. Field data collection continues during the summer period of 1997 in order to fine tune the Knowledge Based System.

Task 5. Regional-level Snow, Wind and Fire Risk Models

Sub-task 5.1. Climatology of Wind and Snow in Relation to Topographic Variability

and Temporal Incidence

A snow review paper has been prepared in collaboration with 3 participants (P01, P04 and P05) within Sub-task 3.3 (see Nykänen et al. 1997) which summarises also the current state of knowledge of snow damage to trees for Sub-task 5.1. This information provides a means of identifying the key site and climatological elements which require to be modelled. A strategy has been identified for developing a snow model for the UK and it is currently being implemented. Further work is also being developed to look at the joint occurrence of wind and snow, so that the correct interactions are included in the climatological modelling. Within the period of report P01 has collected also wind data for generating the surface of windspeed for Finnish test area. Also a landuse classification for calculating the regional wind pattern for the Finnish test area has been made by P01.

The statistical model (Jackson, 1977) has been implemented using GIS by P05, and layers of snow incidence statistics have been calculated for the UK. Some difficulties were experienced with model validation because the available Meteorological Office Data is largely unsuitable. Modelling snow incidence is a persistent problem and a special session was held to discuss the issues at the EC Project meeting in Umea. The issues experienced are similar for Sweden, Finland and the UK, and generally stem from inadequate meteorological information. The model has been used to calculate snow accumulation for 24 hour periods with different return periods, and this was validated using snow lie data with reasonably consistent results. Sensitivity testing of the model will be completed within a fortcoming couple of months. The snow, wind and tree mechanistic models are also now being combined. The combination of snow and wind is being investigated by assessment of the joint probabilities statistics since the interaction of these two damage agents is critical for assessing damage risk, particularly in the UK.

Within this Sub-task, P07 has also made Swedish snow and wind atlases available for GIS-layers for the continuous work within Task 6. P04 has tested a variety of methods of predicting windspeeds in complex terrain. A form of geographic predictors proved to be as successful as numerical airflow models (Suarez et al, in prep). Digital layers of elevation and surface roughness have also been used by P04 to run an airflow model for test sites of P01 and P03; the wind surfaces that the model produces will be used for validation and further model development.

Sub-task 5.2. Construction of Geographical Database and Use of Image Processing

The compilation of geographic database for the study areas has been continued and spatial data has been converted to agreed format. For Finnish test areas, P01 has made available all the preprocessing of satellite images and field measurements of occurred wind damage. The data has been stored to the geographic database. Since the beginning of the project we are making the compilation of all the relevant analogic and digital available datasets, for the defined study area. Some layers are ready to use. The layers that are actually present in the geographic digital database are listed in this report. Most of the layers needed for the portuguese study area spatial database are already organized in a unified cartographic system and satellite imagery has been geographic and radiometricly corrected for use in Sub-task 5.4. The metadata forms, organised by the P05 are being used to collect and collate information about the datasets through the project World Wide Web (WWW) site. This is an efficient, simple and timely mode of gathering the information and storing it in a central location for viewing by all participants. The form ensures complete documentation of the information about the data in a standard format, and thus facilitates effective communication between participants, and provides documentation for present and future use.

Sub-task 5.3. Explore Relevance of Pan-European Datasets of Eurostat and CORINE

Although this task comprises a live document which will be continuously updated, the groundwork for the majority of the information has been completed, and further updates will occur using input from the completed metadata forms on the WWW.

Sub-task 5.4. Regional Classification of Fuel Types Using Mixture Models and Functional Vegetation Classification

The data produced in Sub-tasks 2.4, 3.4 and 4.3, by P03 and P06 have been integrated in the geographic database and used for processing and analysis of the Landsat5-TM image acquired in 1996. Models for predicting shrub and pine stand biometrics parameters from spectral vegetation indices and linear mixture models (LMM) techniques has been developed. Vegetation Indices, resistant to the atmospheric effect, yield good results on the appraisal of stand structural characteristics, namely timber volume and basal area per hectare, and weaker correlations are obtained with LAI and the number of trees per hectare. The LMM models, independently of using image or reference endmembers, have shown to be efficient for discriminating pine stands from shrublands, based on the proportion of the shade endmember. The LMM models for understory characterization need to be built with reference endmembers. In the study area coexist different species of shrubs and results show that LMM are shrub species dependent. Because of the dimensionality of the remotely sensed data used in this study, the LMM can only include one shrub species. Because of the sensitivity of the models to the shrub species and because of the dimensionality of the multispectral data used in this study, LMM with a single set of endmembers cannot be applied to all the pine stands of the regional area. P03 is now therefore developing a multi-endmember approach, where the set of endmembers used in the LMM may change from pixel to pixel.

Sub-task 5.5. Knowledge Base System Construction for Fuel Hazard Mapping

A Neural Network based on a standard backpropagation algorithm is ready and under test in the dataset compiled in task 4.4. The Neural Network was programmed in Delphi from scratch to be used for better control of all the parameters. After the test fase the Neural Network will be applied to the larger dataset that includes the additional fuel points collected during the summer. Other methods for detecting the patterns of fuel distributions are under study for imediate implementation (a genetic algorithm and a fuzzy Neural Network).

Sub-task 5.6. Fire Risk Model Construction

A piece of software named FireMap was conceived, developed and implemented for the evaluation of fire risk. This stand-alone GIS application uses three types of information - Topography, Fuels and Wheaher conditions - and generates fire risk digital maps as well as others fire characteristics maps by application of Rothermel (1972) Fire Behaviour model. FireMap is a PC (Windows95) based application developed from scratch in Delphi and C++ and implemented in a user-friendly environment for visualisation of information inputs and outputs. FireMap is used to produce fire risk maps based on the fuel models map which is being produced in Sub-task 5.5 and on topographic information already compiled in Sub-task 5.2. The weather information can be supplied in the form of scenarios for mean summer conditions. However, the applicability of FireMap is beyond the production of a fixed fire risk map, for it consists of a tool for evaluating the impact on fire risk of different fuel management strategies and changing whether scenarios, at a local to regional level.

Task 6. Integrating Components from Tree/Stand Regional-level to Produce an Unified Risk Model

Sub-task 6.1. Integrating the Component Models

The demonstration which was set up in 1996 allowed several issues to be identified and explored by the project group. This demonstration involved the formal documentation of selected models through the web metadata forms, and trial exchanges of data and models between participants in different countries. The issues arising from this exchange, together with the success of the web, have permitted the formulation of a prototype Integration Framework during the October 1996 meeting in Umea. These plans have been implemented on the WWW so that a working prototype could be discussed at the project meeting in Braemar, March 1997. The prototype is being developed "live" on the private WWW pages so that it can be viewed by project participants who can give immediate feedback on the developments as they progress. The prototype includes: an introduction to integrated risk assessment and application of silvicultural strategies to reduce risk using a demonstration forest; access to comprehensive model descriptions, model output, information about model reliability and use to derive silvicultural strategies; data for model development, validation and demonstration runs; data issues of quality, availability, scale and relevance; information about and links to project participants and their roles in the project; information about silvicultural advice in the context of the project findings. The logic behind this approach to integration is that the formal descriptions of models and data, pointers to demonstrations of their use, and on-line illustrations of their applicability, through a single point of access, provides a flexible and robust framework.

Within this sub-task 6.1, empirical and mechanistic models have been made available by participants to be used for the integration of the component models for the predictions of wind damage and snow damage (see sub-tasks 3.1, 3.2 and 3.3).

Sub-task 6.2. Scale Issues and Error Propagation

Scale and error studies explored using the models will be an important component in the prototype and a lot of work is ongoing to be completed for this Sub-task within next months by participants. However, P07 has already tested the logistic models (14) for predictions of snow and wind damage. Initially preliminary models have been developed using a sub-sample of data from P07 Nationwide NFI data-base (the county of Västerbotten in northern Sweden). However, lately all permanent sample plots have been used for model development with great statistical care regarding inclusion of variables have been taken, i.e. all of the included variables are statistically significant (P<0.05). The developed preliminary model using tree characteristics have, so far, only been tested against Swedish data base (NFI) for two other counties, one adjacent to Västerbotten and one in southern Sweden. The predictability was better for the adjacent county, partly depending on the different origin of the Scots pine trees in northern and southern Sweden. Another explanation could be that no actual damage was present at sites with the highest estimated probabilities. Respectively, the developed preliminary models using tree, stand, and site data have been tested against temporary sample plots from Västerbotten and have shown good predictability. When testing the preliminary three models (stand, site, and tree, stand, and site data) the predictability for the county in southern Sweden was, however, also low. To date, all the models using tree characteristics and tree, stand, and site characteristics as input variables developed for the whole country of Sweden have been evaluated.

P05 and P04 are currently investigating the implications of using different scales of soils data for the wind risk modelling, and assessing the applicability of the European 1:1million scale soils map, and the Macaulay Land Use Research Institute soils data for Scotland. A report will be made on these investigations, and the results will be available as part of the WWW interface.

Task 7. Testing Models against Independent Data and Outlining Implications for Silvicultural Strategies

Sub-task 7.1. Model Testing by Application of Change Detection System to Finnish Test Area; Detecting Wind Damages on Stand Level by Landsat TM Images

The change detection method was developed by P01 and tested using Landsat TM images. The key results was that drastic damages could be classified correctly, but partial damages were classified half correctly and half wrong (see Varjo 1996). The testing of the mechanistic wind damage model (HWIND) against field detected wind damage in Finnish test area has been started at the end of 1996 and some preliminary computations are already available by P01 for simulated critical windspeeds for wind damage. The testing will now be completed within a couple of months using airflow model results made available for test site by P04 based on actual windspeeds measured at the time of damage events in nearby climate station (Talkkari et al. 1997). As an additional work (not mentioned in technical annex), P07 will try to test their models on Finnish test site data.

Sub-task 7.2. Model Testing Through Portuguese Forest Service

An approach for testing the fire risk maps produced by FireMap has been outlined and part of the required data has been provided by P06 and organised in a unified spatial dataset (Sub-Task 5.2). The conceived strategy consists on the study of patterns between the high risk areas and the burned areas during the past five years in a predefined location of high fire occurrence. The feasibility of test of concordance between this two datasets is dependent on the outputs of Sub-task 5.5 which are still under processing. The results of this test will provide not only a check on the fire risk evaluation procedure but also an assessment of FireMap usage in an operational framework.

Sub-task 7.3. Model Testing through Forestry Commission Windthrow Monitoring Areas

and Forest Districts

To be completed within a couple of months.

Task 8. Final Products, Documentation and Identification of New Opportunities

Sub-tasks 8.1. Dissemination of Project Information and Results

The World Wide Web (WWW) pages of the STORMS project (also by individual participants with the links to the project pages) are continuing as a valuable dissemination medium to communicate the aims, methods and findings of the project. The web site is also being used as a means of formally documenting the models and data for use in Task 6. The project publicity leaflets have been distributed to all participants and also sent to DGXII. A poster for the project was presented at GIS Research UK Conference (STORMS, 1996) and was well received. For example, for Swedish readers the STORMS project will be referred to in the forthcoming issue of the magazine ERA (pp. 2-3, No 6-7: 1997), which covers the topic of rational use of electricity. Furthermore, discussions have been carried out by P07 with the Swedish Forest Company MoDo on how to implement the developed models into forestry management practices (May 23, 1997). The public and private project web pages are being demonstrated to interested parties. The participants agreed to "responsible" demonstrations of the work, which would allow visitors to understand the contributions the project was making without compromising the publication potential of the materials contained within the pages. A list of official web page visitors is available on the web for participant perusal.

Sub-task 8.2. Documentation of Project Achievements

Documentation of many research findings is currently under work in many Sub-tasks , i.e. within scientic journals and conference papers etc as well as within STORMS www-pages (see Appendix 1). In addition, there are several linked initiatives into defining standards for metadata for spatial data in Europe. The metadata/model forms (being used within Task 5.3) disseminated through the World Wide Web (Task 8) provide an infrastructure for the compilation of (http://www2.echo.lu/gi/gi2000/en/egii/gi2000dd.html), within the Geographic Information 2000 programme. The Tasks address two aspects of the document in particular: 1. metadata dissemination; and 2. a metadata service (for the STORMS project). Additional outputs from project tasks, specifically aimed at communication and dissemination of the issues being tackled include a `flythrough' of the Cwm Berwyn study forest to shows the pockets of damage within the forest and their association with the underlying elevation and historic patterns of drainage. This flythrough is being converted into a form which will be accessible through the WWW pages as part of the Task 6 demonstrator.

Appendix 1. Dissemination of the STORMS project.

DISSEMINATION within STORMS between 1995-1997

The following publications and scientific manuscripts have been published, are in press, accepted or submitted within the first 30 months of Project by Participants:

Bell, P. D., Quine, C. P. and Wright, J. A. 1995. The use of digital terrain models to calculate windiness scores for the windthrow hazard classification. Scottish Forestry 49(4): 217-225.

Caetano, M.S., Mertes, L.A.K., Cadete, L.and Pereira J.M.S. 1996. Assessment of AVHRR data for characterizing burned areas and postfire vegetation recovery. EARSEL International Workshop: Remote Sensing and GIS Applications to Forest Fire Management. Alcalá de Henares, Spain Sept 79 . 4952pp.

Chalmers, S. 1996. The use of the Criterion Survey Laser and ARC/INFO Geographic Information System (GIS) to Survey, Analyse and Predict Windthrow. BSc thesis. University of Aberdeen (unpubl.).

Dunham, R.A. 1996. The influence of growth rate on the wood and stem

properties of silver birch (Betula pendula Roth)" PhD thesis, Aberdeen University, Scotland.

Gardiner, B.A., 1997. Standing up to Storms, Biologist 44(2), 318-321.

Fridman, J. and Valinger, E. 1997. Modelling probability of snow and wind damage at sites using Scots pine sample plot tree, stand, and site characteristics. Scandinavian Journal of Forest Research (in press).

Gardiner, B.A. and Stacey, G.R. 1995. Designing Forest Edges to Improve Wind Stability. Forestry Commission Technical Paper 16, Forestry Commission, Edinburgh.

Gardiner, B.A., Stacey, G.R., Belcher, R.E. and Wood, C.J. 1996. Field and wind tunnel assessments of the implications of respacing and thinning for tree stability. Forestry 70:(3), in press.

Granander, M. 1996. Vääntömomentti koivun (Betula pendula), kuusen (Picea abies) ja männyn (Pinus sylvestris) kaatamiseksi ja katkaisemiseksi staattisella voimalla kuormitettaessa. Metsäteknologian ja puutalouden pro-gradu. Joensuun yliopisto, Metsätieteellinen tiedekunta (in Finnish). (English translation: Critical applied moments for uprooting and stem breakage of Birch spp, Norway spruce and Scots pine in tatic loading tests, Thesis for M.Sc., Faculty of Forestry, University of Joensuu).

Lundqvist, L. and Valinger, E. 1996. Stem diameter growth of Scots pine trees after increased mechanical load in the crown during dormancy and (or) growth. Annals of Botany 77, 59-62.

Mackie, A., Bell,P.D., and Quine, C.P. 1996. Where on earth are we with GPS? (Use of Global positioning systems in forests). Forestry and British Timber, October 1996, 3941.

Nykänen, M-L, Peltola, H., Quine, C., Kellomäki, S., Broadgate, M. 1997. Factors affecting snow damage of trees with particular reference to European conditions. Silva Fennica (in print).

Peltola, H. 1995. Studies on the mechanism of wind-induced damage of Scots pine. Research Notes 32, University of Joensuu, Faculty of Forestry. D.Sc. (Agr. and For.) thesis. 28 p.

Peltola, H. 1996a. Swaying of trees in response to wind and thinning in a stand of Scots pine. Boundary-Layer Meteorology 77:285-304.

Peltola, H. 1996b. Model computations on the wind flow and turning moment by wind for Scots pine along the margins of clear-cut areas. Forest Ecology and Management 83:203-215.

Peltola, H. 1996c. Modelling the mechanism of wind-induced damage of Scots pine. In: The Finnish Research Programme on Climatic Change. Final Report. (Ed. Jaana Roos). Publications of the Academy of Finland 4/96. pp. 260-263.

Peltola, H., Kellomäki, S. and Väisänen, H. 1997a. Model computations on the impacts of climatic change on soil frost with implications for windthrow risk of trees. Climatic Change (Submitted).

Peltola, H., Nykänen, ML. and Kellomäki, S. 1997b. Model computations on the critical combination of snow loading and windspeed for snow damage of Scots pine, Norway spruce and Birch sp. at stand edge. Forest Ecology and Management (in print).

Quine, C.P. 1996. The chance of a windfall. Forestry and British Timber, August 1996, 1719.

Quine,C.P., Mackie,A.L., and Bell,P.D. 1997. In the woods with GPS - Global positioning systems in forest use. Mapping Awareness,11(1), 28-30

Suarez, J. 1995. The Use of WaSP Airflow Model to Estimate the Wind speed in Kintyre. Unpublished Forestry Commission Report.

Suarez, J. 1996. A comparison of methods of estimating the windspeed in Cowal. Unpublished Forestry Commission Report.

Valinger, E. and Fridman, J. 1997. Modelling probability of snow and wind damage at sites using Scots pine tree characteristics. Forest Ecology and Management (in press).

Valinger, E. and Pettersson, N. 1996. Wind and snow damage in a thinning and fertilization experiment in Picea abies in southern Sweden . Forestry 69, 25-33.

Valinger, E., Lundqvist, L. and Sundberg, B. 1995. Mechanical bending stress applied during periods of cambial dormancy and (or) activity stimulates diameter growth of Scots pine seedlings. Canadian Journal of Forest Research 25, 886-890.

Varjo, J. 1996. Controlling continuously updated forest data by satellite remote sensing. International Journal of Remote Sensing 17(1):43-67.

Vasconcelos, Maria J. Perestrelo. 1995. Integration of remote sensing and geographic information systems for fire risk management. EARSEL International Workshop: Remote Sensing and GIS Applications to Forest Fire Management. Alcalá de Henares, Spain Sept 7-9 129-149 pp.

Wade, N. 1996. A comparison of the strength properties of windthrown, windsnapped and standing timber, derived from testing of small clear specimens of Picea sitchensis. BSc thesis. University of Aberdeen (unpubl.).

Zipse, Mattheck C. , Grabe and Gardiner, B.A. 1997. The effects of wind on the mechanical properties of wood in Scottish Beech trees. Scottish Forestry (in press).

Conference presentations

Blackburn,G. and Gardiner,B.A. 1997. The growth response of Sitka spruce trees to changes in wind-loading. For International Symposium on Plant Biomechanics, Univ of Reading, 7-12 Sept 1997 and written for proceedings.

Broadgate, M. 1996. STORMS Project Group 1996 Integrating tree and environmental models using GIS to develop silvicultural strategies for minimising forest damage. GIS Research UK Conference Proceedings, April 1996 (Poster presentation).

Caetano, M.S., and Pereira, J.M.S. 1996. The effect of the understorey on the estimation of coniferous forest leaf area index (LAI) based on remotely sensed data. Presented on the conference on Signal and Image Processing for Remote Sensing, Taormina, Italy, 23-27 September, 1996. Caetano, M. and J. Pereira (1997), Analysis of the integrated (overstory/background) hyperspectral response of pine stands. Accepted for presentation on the Aerospace Remote Sensing: Remote Sensing for Agriculture, Ecosystems, and Hydrology.

Caetano, M., J. Paúl, T. Oliveira, J. Pereira and M. Vasconcelos. 1997. Forest understory characterization with Landsat TM data. Accepted for presentation on the Conference of the Remote Sensing Society 1997: Observations and Interactions.

Caetano, M., T. Oliveira, J. Paúl, M. Vasconcelos and J. Pereira. 1997. Mapping shrublands and forests with multispectral satellite images based on spectral unmixing of scene components. Accepted for presentation on the Aerospace Remote Sensing: Remote Sensing for Agriculture, Ecosystems, and Hydrology.

Gardiner, B.A. and Peltola, H. 1996. The development and testing of models for predicting the critical windspeed to damage trees. In Conference Abstracts: Second International workshop on disturbance dynamics in boreal forests, in Quebec, Canada, in August 26-30, 1996. Poster presentation.

Gardiner, B.A. and Quine, C. 1997. Forecasting for wind damage to forests, Oral presentation to Royal Meteorological Society conference 'Orographic processes in weather forecasting and climate modelling', London, 16.4.97.

Miller, D., Quine, C. and Broadgate, M. 1996. The application of digital photogrammetry for monitoring forest stands. In: The Proceedings of Application of Remote Sensing in European Forest Monitoring, Joint Research Centre, in Vienna, October 1996.

Peltola, H. 1996d. Model computations by the mechanistic model for wind and snow damage of single tree. In Conference Abstracts: Second International workshop on disturbance dynamics in boreal forests, in Quebec, Canada, in August 26-30, 1996. Oral presentation.

Peltola, H., Kellomäki, S., and Väisänen, H. 1995. Model computations on the impacts of the climatic change on the soil frost and the risk of trees for windthrows. In: Climate Change, Biodiversity and Boreal Forest Ecosystems -Conference Abstracts, in Joensuu, in Finland, 30th July to 5th August, 1995. (IBFRA). Poster presentation.

Peltola, H., Kellomäki, S., Väisänen, H. and Nykänen, M-L. 1996. Impacts of climatic change on soil frost and the risk of trees to windthrows. In: Finnish Climate Change- Conference in Tampere 4-5, June 1996. Poster presentation.

Quine, C. On site presentation to Forestry Commission Research Advisory Committee meeting in Wales, May 1997.

Quine, C. and Suarez, J. 1997. The wind risk model as an example of multi-scale GIS modelling for Institute of British Geographers Conference, Exeter, January 1997. Oral presentation.

Valinger, E. and Fridman, J. 1997. Models for snow and wind damage assessments in boreal pine, spruce, and birch forests. Abstract submitted to IBFRA (International Boreal Forest Research Associations) Conference "Disturbance in Boreal Ecosystems; Human Impacts and Natural Processes", Duluth, USA, August 4-8, 1997.

Miller, D. "Risk appraisal for environmental management. In: Proceedings of the Joint European Conference on Geographical Information Systems, Vienna, April 1997. Oral Presentation

Manuscripts in preparation

Blackburn,G. and Gardiner, B.A. 1997.The physiological response of trees to strong winds. For Tree Physiology.

Caetano, M. (1998) "Understory charcterization with remotelly sensed data" PhD dissertation to be presented at Instute of Agronomy, Techical University of Lisbon.

Gardiner, B.A. and Peltola, H. 1997. The development and testing of models for predicting the critical windspeed to damage trees. To be submitted.

Hassinen, A., Lemettinen, M., Peltola, H., Kellomäki, S., and Gardiner, B.A. 1997. Prism based measurement system to monitor tree swaying under wind loading. Submitted to Agriculture and Forest Meteorology.

Kerzenmacher T. and Gardiner, B. A. 1997. A mathematical model to describe the dynamic behaviour of a spruce tree to the wind. Submitted to Trees.

Oliveira, T. M. 1997. MSc Thesis submitted to Instute of Agronomy, Techical University of Lisbon.

Paúl, J.C. 1997. "Estimation of Leaf Area Index in maritime pine stands. From stand-level to regional-level" MSc Thesis submitted to Instute of Agronomy, Techical University of Lisbon.

Paúl, J.C., J.M. Pereira. 1997. "Leaf Area Index Measurement by Allometric Relations and Canopy Transmittance in Maritime Pine Stands".

Paúl, J.C., J.M. Pereira. 1997. "Satellite Remote Sensing of Forest Stands Variables in Maritime Pine Plantations".

Peltola, H. and Kellomäki, S. 1997. Assessing risk of wind damage to forests for forest management. Manuscript in preparation.

Peltola, H., Kellomäki, S., Väisänen, H., Ikonen, V-P. 1997c. HWIND: A mechanistic model for wind and snow damage of Scots pine, Norway spruce and birch sp. Manuscript in preparation.

Peltola, H., Kellomäki, S., Hassinen, A., and Granander, M. 1997d. Mechanical stability of Scots pine, Norway spruce and Birch spp. in Finnish tree pulling experiments. Manuscript in preparation.

Päätalo, M-L, Peltola, H. and Kellomäki, S. 1997. Assessing risk of snow damage to forests for forest management. Manuscript in preparation.

Päätalo, M. 1997. Factots affecting risk of fire damage with special reference to northern and southern Europe. Sent for submission to Silva Fennica (6/97).

Quine, C.P. and Bell,P.D. 1997. Forest monitoring of windthrow occurrence and progression. Forestry (submitted).

Quine, C.P. and White, I.M.S. 1997. The use of distance limited TOPEX. For Forestry.

Suarez, J.C., Gardiner,B.A. and Quine,C.P. 1997. Comparison of windspeed methods in complex terrain. For Meterological Applications.

Talkkari, A., Peltola, H., Kellomäki, S., Suarez, J. and Gardiner, B.A. 1997. Testing the mechanistic wind damage model against independent data: A GIS based application. Manuscript in preparation.

Valinger, E. and Fridman, J. 1997. Models for snow and wind damage assessments in boreal pine, spruce, and birch forests. (In prep.)

Other related papers to Storms project finished within the period of report by participants:

Gardiner, B.A. 1995. The interaction of wind and tree movement in forest canopies. In: Wind and trees. (Eds. Coutts, M. P. and Grace, J.). Cambridge University press, Cambridge. pp. 41-59.

Hannah, P., Palutikof, J. P. and Quine, C. P. 1995. predicting windspeeds for forest areas in complex terrain. In: Wind and trees. (Eds. Coutts, M. P. and Grace, J.). Cambridge University press, Cambridge. pp. 113-129.

Inglis, D. W. F., Choularton, T. W., Stromberg, I. M. F., Gardiner, B. A. and Hill, M. 1995. Testing of a linear airflow model for flow over complex terrain and subject to stable, structured stratification. In: Wind and trees. (Eds. Coutts, M. P. and Grace, J.). Cambridge University press, Cambridge. pp. 88-112.

Quine, C. P. 1995. Assessing the risk of wind damage to forests: practice and pitfalls. In: Wind and trees. (Eds. Coutts, M. P. and Grace, J.). Cambridge University press, Cambridge. pp. 379-403.

Rodgers, M., Casey, A., McMenamin, C. and Hendrick, E. 1995. An experimental investigation of the effects of dynamic loading on coniferous trees planted on wet mineral soils. In: Wind and trees. (Eds. Coutts, M. P. and Grace, J.). Cambridge University press, Cambridge. pp. 204-219.

Askaner, M. 1997. Fler stormar hot mot elnät och vindkraftverk. ERA 6-7, 2-3. (In press.)

Meetings:

Project planning meeting was arranged on 24-25th February 1995 in Lisbon, Portugal.

Second project meeting was arranged on 10-13th, August 1995 in Tampere and Joensuu, Finland.

Third project meeting was arranged on 13-17th, March 1996 in Inverary, Scotland.

Project mid-term meeting was arranged on 4-5th, July 1996 in Brussels, Belgium.

Fifth project meeting was arranged on 23-27th, October 1996 in Umeå, Sweden.

Sixth project meeting was arranged on 28th March to 4th April 1997 in Braemar, Scotland.

Models developed:

A self extracting copy HWIND-model for Windows 3.1 is available on Joensuu University ftp-site (gis.joensuu.fi /hwind/windows/hwind09.exe).

The first version of the stand alone empirical model (treesnap.exe) to calculate critical wind speeds for damage and base bending moments has been made available to participants on the Edinburgh University ftp site (ftp.ed.ac.uk/pub/risk).

Growth models developed by Soederberg and Ekoe at Swedish University of Agricultural Sciences in Umea, Sweden using single tree and stand characteristics were made available to other participants.

FireMap v1.0 (for Windows95 or WindowsNT3.51). A software for generating fire risk maps under alternative weather scenarios and fuel management strategies.

A model for estimating single tree (Pinus pinaster) Leaf Area, based on measurements of standard dendrometric variables.

A model for evaluating maritime pine stand Leaf Area Index, based on measurements of light transmittance through the canopy.

A regression model between biomass and spectral characteristics for mediterranean shrubs.

Databases constructed:

Finda.xls (Finnish tree pulling database during unfrozen soil conditions for Scots pine, Norway spruce and birch spp) is available on Joensuu University ftp-site.

Finfrost.xls (Finnish tree pulling database during frozen soil conditions for Scots pine) is available on Joensuu University ftp-site.

EDGE.XLS: Data on bending moment as function of distance from forest edge and stand density (Excel 5.0 format) has been placed on the Joensuu ftp site (gis.joensuu.fi/metsa3/users/damage/incoming/fc/).

ACSCOTP.XLS: Spreadsheet which provides the calculated wind and snow risk values for the sample plots within the County of Vasterbotten in Sweden based on single tree characteristics (Excel Format)

A spectral library for seven mediterranean shrubs.

A fuel point sample database resulting from field surveys, geographical and spectral analysis.

A tree-level dendrometric database obtained from mesurements by destructive methods in 30 maritime pine trees.

A stand-level dendrometric and radiometric database resulting from measurements of dendrometric variables and light transmittance in 25 field plots of maritime pine stands.

A shrubs biometric database obtained from measurements in 21 plots.

Other documentation:

The results of each task and participant work are being made available on the World Wide Web site for dissemination (both in Storms pages and individual participant pages).

The updated Task 1 document pages and summary diagrams can be found on the ftp site in the directory air/task1/.

A report has been produced as a result of the snow modelling workshop and has been distributed to both workshop and project participants. A subsequent workshop is planned to discuss the success of the adopted strategies to the modelling approach (Sub-task 5.1).

Metamodel and metadata forms are all currently available on the web. As the project progresses more of this will be transferred to the public pages. Eventually the developed Integrated Risk Model interface will be publicly available over the web. The information added using the form will be stored automatically on the ftp site, and will thus be available for perusal by all participants (Sub-task 5.2).

The report detailing information about Pan-European data sets will be available on the ftp site and accessible via the WWW pages (Sub-task 5.3).

The summary diagrams are currently available on the ftp site and can be accessed by all participants there. They are also to be added to the Task 1 planning document (Task 6).

BENDMOM.WP6: Document discussing the derivation of empirical relationships to describe the change in wind loading as a function of stand spacing, tree height and distance from the forest edge has been placed on the Joensuu ftp site (gis.joensuu.fi/metsa3/users/damage/incoming/fc/).