Quantifying spatial and temporal patterns of forest disturbance over a quarter century and across three distinct regions of the US

Katelyn Dolan, University of Maryland, kdolan@umd.edu (Presenter)
George Hurtt, University of Maryland, gchurtt@umd.edu
Chang Huang, University of maryland, chhuang@umd.edu
Jeffrey Masek, NASA GSFC, jeffrey.g.masek@nasa.gov
Justin Fisk, University of Maryland, fisk@umd.edu
Ralph Dubayah, University of Maryland, dubayah@umd.edu

Forest disturbance and recovery strongly influence forest structure, function and the ecosystem services they provide. The aim of this study was to utilize the long temporal record of the Landsat data archive and the highly automated Vegetation Change Tracker (VCT) to quantify spatial and temporal patterns of disturbance rates and patches across three distinct regions of the conterminous US. Results show significant distinctions in disturbance rates, gap sizes and patterns of disturbance between the Northeast (UL-p012r29* LR- p013r30), Northwest (p045r029), and Southeast (p016r035) study regions. The Southeast study region had both the highest average annual rate of forest disturbance at 2% and the highest inter- annual variability. The Northwest study region fell in the middle with an average annual rate of disturbance of 1.1%, while Northeastern site had the lowest average annual rate at 0.6% In an analysis of the percent of forest area disturbed over a range of gap sizes, nearly 100% of disturbed area in the two Eastern sites came from gaps smaller than 100 ha, whereas approximately 10% of annual disturbed area in the Northwestern study site was caused from disturbances effecting areas greater than 100 ha. The northeastern site was dominated by smaller disturbances with ~50% of all forest area disturbed annually occurring in patch sizes less 1ha. The Northeastern site was the only region to show a significant temporal trend between the 1986 to 2010 study period. Within regions strong inter regional patterns of disturbance could be observed between geophysical and political boundaries. Continued research is needed on the severity and mechanism classification forest disturbance. A more detailed intra-regional analysis preformed in New Hampshire, the Northeastern region, showed strong intra-regional trends in rates, sizes and severity of detected disturbance between physical and political boundaries being. Results have implications on various sampling regimes ability to adequately capture disturbance across the regions and thus implications on estimates of forest carbon storage and flux.

Presentation Type:  Poster

Session:  General Contributions   (Tue 4:35 PM)

Associated Project(s): 

• Hurtt, George: Using NASA Remote Sensing and Models to Advance Integrated Assessments of Coupled Human-Forest Dynamics for North America ...details

Poster Location ID: 116