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Characterizing environmental change in interior Alaska (1982-2012) using multi-temporal, multi-scale remote sensing data and field measurements

Informally Refereed

Abstract

We investigate how vegetation in the Tanana Valley of interior Alaska (120,000 km2) has responded to a changing climate over the preceding three decades (1982-2012). Expected impacts include: 1) drying of wetlands and subsequent encroachment of woody vegetation into areas previously dominated by herbaceous and bryoid vegetation types, 2) changes in forest composition resulting from succession processes within burned areas, 3) mortality and defoliation from increased insect activity attributable to a warming climate, 4) effects on tree growth attributable to drought stress and/or reduced photosynthetic capacity, and 5) expansion of woody vegetation at the tree line. To characterize and quantify these changes occurring over the full range of environmental conditions present in this vast region, we plan to use a unique resource of multi-temporal and multi-scale remote sensing data to analyze changes observed between 1) field data and large-scale photographs collected in 1982 over a selection of inventory plots within the western Tanana Valley region, and 2) low-altitude airborne digital imagery collected over these same inventory plots in 2012. Detailed stand- and plant-level changes observed over 40-ha remeasured photo plots will be scaled up and used to inform an analysis of changes in vegetation condition observed in spectral trajectories obtained from a time series of Landsat Thematic Mapper/Enhanced Thematic Mapper Plus imagery over this 30-year period.

Parent Publication

Keywords

statistics, estimation, sampling, modeling, remote sensing, forest health, data integrity, environmental monitoring, cover estimation, international forest monitoring

Citation

Andersen, Hans-Erik; Pattison, Robert. 2012. Characterizing environmental change in interior Alaska (1982-2012) using multi-temporal, multi-scale remote sensing data and field measurements. In: Morin, Randall S.; Liknes, Greg C., comps. Moving from status to trends: Forest Inventory and Analysis (FIA) symposium 2012; 2012 December 4-6; Baltimore, MD. Gen. Tech. Rep. NRS-P-105. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. [CD-ROM]: 310-313.
https://www.fs.usda.gov/research/treesearch/42768