Andrew J. Hansen, Linda Phillips, Ralph Dubaya, Scott Goetz, Michele Hofton


National Aeronautics and Space Administration (NASA)

Resulting Manuscript

Hansen, A.J., L.B. Phillips, R. Dubayah, S. Goetz, and M. Hofton. 2014. Regional-scale application of Lidar: Variation in forest canopy structure across the southeastern US, Forest Ecology and Management. .pdf

Project Overview

The science goal of this project is to better understand the relationship between biophysical factors and canopy structure at the landscape scale, and also to link remote sensing of vegetation structure with species distribution and abundance modeling . Our previous research suggests species richness has a positive decelerating or unimodal relationship with productivity at broad spatial scales and that a unimodal relationship for bird species richness exists in North America. The current research will address questions regarding the causal factors of this relationship by incorporating state of the art vegetation structure data obtained from the LVIS sensor.

In particular we seek to answer the following four questions:

  1. For undisturbed areas, how much variation in forest canopy structure is there within and among ecoregions in the southeast US and what are the biophysical factors that explain this variation?
  2. How much difrerence is there in canopy structure amont undistrubed, disturbed and plantation forests?
  3. For natural routes, how much does vegetation structure versus biophysical factors contribute to models of bird species richness and guild richness?
  4. For all routes, how does land use modify richness from the biophysical expectation?
  5. What explains the downturn in richness at the highest annual GPP levels? Competitive dominance? Soil fertility? Disturbance history? Land use?

This work will be performed for 59 Breeding Bird Survey routes that overlap the 2400 mile LVIS transect in the Southeast US. This southeast US transect was selected to sample the region of North America where primary productivity is intermediate and high and the relationship between productivity and bird species richness is negative (Phillips et al. 2010). The analysis will be performed at three spatial scales: BBS stop locations, 5 mean summary of stop locations, and entire BBS route. The general approach to the research is illustrated here.

updated August 26, 2014