A Spatial Landscape Model of Forest Patch Dynamics and Climate Change Scientific Investigations Report 2007-5040 U.S. Department of the Interior U.S. Geological Survey A Spatial Landscape Model of Forest Patch Dynamics and Climate Change By Richard T. Busing Scientific Investigations Report 2007-5040 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark Myers, Director U.S. Geological Survey, Reston, Virginia: 2007 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Suggested citation: Busing, Richard, 2007, A Spatial Landscape Model of Forest Patch Dynamics and Climate Change: U.S. Geological Survey Scientific Investigations Report 2007-5040, 50 p. iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Purpose and scope ........................................................................................................................................1 Methods and model constructs ..................................................................................................................2 The patch dynamics framework .........................................................................................................2 Modeling forest patch dynamics ..............................................................................................2 The FORCLIM patch model .........................................................................................................2 General background and unique features ......................................................................2 Strengths of the FORCLIM version 2.9 modeling approach .........................................2 Weaknesses of the FORCLIM version 2.9 modeling approach ...................................4 The landscape model framework ......................................................................................................5 Patch, block and landscape units .............................................................................................5 Simulation tract size, shape and structure ..............................................................................5 Capabilities of the FOREL Model ........................................................................................................5 Transect simulations ..................................................................................................................5 Dispersal simulations ..................................................................................................................6 Climate change simulations .......................................................................................................6 Results .............................................................................................................................................................7 Transect simulations ............................................................................................................................7 Dispersal simulations ...........................................................................................................................8 Climate change simulations ................................................................................................................8 Model program structure and use .....................................................................................................8 Summary........................................................................................................................................................11 Acknowledgements .....................................................................................................................................12 References Cited..........................................................................................................................................12 Appendix A Program listing........................................................................................................................14 Appendix B Program inputs and outputs .................................................................................................43 Input files and commands .................................................................................................................43 Example input file for species parameters: ...........................................................................43 Example input file for site parameters: ..................................................................................44 Output file .............................................................................................................................................45 Example of an output file portion: ...........................................................................................45 iv Figures Figure 1. Thinning curve for simulated Pseudotsuga stands using FORCLIM. .................................3 Figure 2. Vegetation map of western Oregon showing the locations of sites along the study transect at 44.13o N latitude. ......................................................................................3 Graphs Showing: Figure 3. Elevations of sites along the study transect at 44.13o N latitude. .........................................3 Figure 4. Forest species composition and basal area along the study transect at 44.13o N latitude. .......................................................................................................................4 Figure 5. Actual and simulated size-class structure in the Cascades Montane Highlands ecoregion characterized by Pseudotsuga-dominated forests. ..........................................4 Figure 6. Nested structure of the landscape simulation grid (or tract). .............................................5 Figure 7. Climate changes along the study transect at 44.13o N latitude. ..........................................6 Figure 8. Simulation landscape surface of a hypothetical mountain with variation in elevation and slope aspect. ..................................................................................................6 Figure 9. Simulated climate variables along the study transect at 44.13o N latitude using the FOREL model. .............................................................................................................7 Figure 10. Simulated climate response variables affecting the growth of Pseudotsuga along the study transect at 44.13o N latitude using the FOREL model. .............................8 Figure 11. Simulated species composition and basal area along the study transect at 44.13o N latitude using the FOREL model. ..............................................................................8 Figure 12. Landscape dynamics after cutting of a 200-year-old Pseudotsuga-dominated forest simulated by FOREL. .......................................................10 Abstract A Spatial Landscape Model of Forest Patch Dynamics and Climate Change By Richard T. Busing Abstract FOREL (a FOREst Landscape model) is an individual-based, multi-scale simulator of forest and climate dynamics. Ratio- nale and design of the model are presented in relation to other forest patch models. Information on implementation of the model is also provided. Capabilities of the FOREL model are demonstrated for forest composition, structure and dynamics along cli- matic gradients. The model relies on a patch simulation approach that has been tested and developed by independent ecologists for more than three decades. Improvements made over the last decade to the simulation of climate effects on trees are incorpo- rated in the landscape model. A single parameterization of the model is capable of simulating major shifts in forest composition and structure across broad climatic gradients. It is responsive along moisture gradients and temperature gradients. The land- scape model is flexible and can be altered easily to test various assumptions about the effects of climate on trees, and the effects of spatial pattern on processes operating within and among forest stands. The spatial structure of the model makes interaction of patches possible. Interactions may include dispersal of propagules and competition for light. The model is a useful tool for projecting temporal climate change effects on forested sites, landscapes and regions. Introduction An individual-based model (sensu DeAngelis and Gross Progress can be made with careful attention to critical assump- 1992) of forest stand and landscape dynamics is a useful tions concerning climate and tree performance (e.g., Bug- tool for multi-scale analyses of issues in forest ecology and mann and Solomon 2000). Patch models, revised and tested, management. Many forest landscape modeling efforts have continue to advance the field of forest-climate