Modeling the size-frequency distribution of forest disturbances

Danxia Song, Department of Geographical Sciences, University of Maryland, dxsong@umd.edu (Presenter)
Chengquan Huang, University of Maryland, cqhuang@umd.edu
Joe Sexton, University of Maryland, jsexton@umd.edu
John R. Townshend, University of Maryland, jtownshe@umd.edu

Forest disturbance is one of the most significant land cover changes in the Earth System because of the resultant transformation in biophysical and ecological properties. The size of a disturbance event can range from individual treefalls to large area clearing due to natural and/or human driving factors. The size distribution of disturbances over an area can shape the structural and functional characteristics of the forests over that area and hence may have implications for important carbon and ecological processes. Therefore, accurate modeling of the size-frequency distribution of forest disturbance is necessary for realistic representation of past disturbances and for prescribing future disturbances in ecosystem models. Existing methods for modeling patch size distribution do not provide an accurate representation of forest disturbances, especially for very large but rare disturbance patches. In this study, we proposed a novel method to model disturbance size-frequency distribution. This method was established based on the widely used power-law model, but had a few added parameters to describe the scattered pattern of disturbance sizes especially at low frequency levels. We have tested this method over China using the Global Forest Cover Change (GFCC) 2000-2005 map. Our results show that this method could significantly improve the representation of the size-frequency distribution while remain the accuracy of total area estimation.

Presentation Type:  Poster

Session:  General Contributions   (Tue 4:35 PM)

Associated Project(s): 

• Related Activity: Related Activity or Previously Funded CC&E Activity not listed ...details

Poster Location ID: 242