Determining the size of a complete disturbance landscape: multi-scale, continental analysis of forest change
- 211 Downloads
The scale of investigation for disturbance-influenced processes plays a critical role in theoretical assumptions about stability, variance, and equilibrium, as well as conservation reserve and long-term monitoring program design. Critical consideration of scale is required for robust planning designs, especially when anticipating future disturbances whose exact locations are unknown. This research quantified disturbance proportion and pattern (as contagion) at multiple scales across North America. This pattern of scale-associated variability can guide selection of study and management extents, for example, to minimize variance (measured as standard deviation) between any landscapes within an ecoregion. We identified the proportion and pattern of forest disturbance (30 m grain size) across multiple landscape extents up to 180 km2. We explored the variance in proportion of disturbed area and the pattern of that disturbance between landscapes (within an ecoregion) as a function of the landscape extent. In many ecoregions, variance between landscapes within an ecoregion was minimal at broad landscape extents (low standard deviation). Gap-dominated regions showed the least variance, while fire-dominated showed the largest. Intensively managed ecoregions displayed unique patterns. A majority of the ecoregions showed low variance between landscapes at some scale, indicating an appropriate extent for incorporating natural regimes and unknown future disturbances was identified. The quantification of the scales of disturbance at the ecoregion level provides guidance for individuals interested in anticipating future disturbances which will occur in unknown spatial locations. Information on the extents required to incorporate disturbance patterns into planning is crucial for that process.
KeywordsDisturbance Scale Extent Ecoregion Spatial statistics Heterogeneity Landscape variability North America Reserve design Contagion
This work was partially supported by NSF Alaska EPSCoR award #OIA-1208927 and the state of Alaska. Thanks is also expressed to Hansen et al. and Google Earth Engine for supplying the data on forest disturbances. Four anonymous reviewers provided helpful feedback.
- Bissonette, J. A. (2012). Wildlife and landscape ecology: effects of pattern and scale. Chicago: Springer Science and Business Media.Google Scholar
- Core Team, R. (2015). R: a language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.Google Scholar
- Hansen, M. C., Potapov, P. V., Moore, R., Hancher, M., Turubanova, S. A., Tyukavina, A., Thau, D., Stehman, S. V., Goetz, S. J., Loveland, T. R., & Kommareddy, A. (2013). High-resolution global maps of 21st-century forest cover change. Science, 342(6160), 850–853. https://doi.org/10.1126/science.1244693.CrossRefGoogle Scholar
- Hijmans, R.J., van Etten, J. (2015). Raster: geographic analysis and modeling with raster data. R Package Version 2.0–12 http://CRAN.R-project.org/package=raster.
- McGarigal, K., Cushman, S.A., Neel, M.C., Ene, E. (2012). FRAGSTATS v3: spatial pattern analysis program for categorical maps. Amherst, MA, USA.Google Scholar
- Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., D'amico, J. A., Itoua, I., Strand, H. E., Morrison, J. C., Loucks, C. J., Allnutt, T. F., Ricketts, T. H., Kura, Y., Lamoreux, J. F., Wettengel, W. W., Hedao, P., & Kassem, K. R. (2001). Terrestrial ecoregions of the world: a new map of life on earth. Bioscience, 51(11), 933–938. https://doi.org/10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2.CrossRefGoogle Scholar
- Pickett, S. T., & White, P. S. (1985). The ecology of natural disturbances. New York: Elsevier.Google Scholar
- Riitters, K., Wickham, J., O'Neill, R.V., Jones, B., Smith, E. (2000). Global-scale patterns of forest fragmentation. Conservation Ecology, 4(2):online.Google Scholar
- Sayler, K. L., Acevedo, W., & Taylor, J. L. (2016). Status and trends of land change in selected US ecoregions-2000 to 2011. Photogrammetric Engineering & Remote Sensing, 82(9), 687–697. https://doi.org/10.1016/S0099-1112(16)30120-3
- Turner, M. G. (1989). Landscape ecology: the effect of pattern on process. Annual Review of Ecology and Systematics, 20(1), 171–197. https://doi.org/10.1146/annurev.es.20.110189.001131.CrossRefGoogle Scholar