Pacific Northwest Research Station

Title: A simple method for estimating potential relative radiation (PRR) for landscape-vegetation analysis.

Author: Pierce, Kenneth B. Jr.; Lookingbill, Todd; Urban, Dean.

Date: 2005

Source: Landscape Ecology. 20: 137-147

Description: Radiation is one of the primary influences on vegetation composition and spatial pattern. Topographic orientation is often used as a proxy for relative radiation load due to its effects on evaporative demand and local temperature. Common methods for incorporating this information (i.e., site measures of slope and aspect) fail to include daily or annual changes in solar orientation and shading effects from local topography. As a result, these static measures do not incorporate the level of spatial and temporal heterogeneity required to examine vegetation patterns at the landscape level. We developed a widely applicable method for estimating potential relative radiation (PRR) using digital elevation data and a widely used geographic information system (Arc/Info). We found significant differences among four increasingly comprehensive radiation proxies. Our GIS-based proxy compared well with estimates from more data-intensive and computationally rigorous radiation models. We note that several recent studies have not found strong correlations between vegetation pattern and landscape-scale differences in radiation. We suggest that these findings may be due to the use of proxies that were not accurately capturing variability in radiation, and we recommend PRR or similar measures for use in future vegetation analyses.

Keywords: aspect, DEM, GIS, solar insolation, species-environment interactions, topographic effects, vegetation distribution

View and Print this Publication (949 KB)

Pristine Version:  An uncaptured or "pristine" version of this publication is available. It has not been subjected to OCR (Optical Character Recognition) and therefore does not have any errors in the text. However it is a larger file size and some people may experience long download times. The "pristine" version of this publication is available here:

View and Print the PRISTINE copy of this Publication (1.17 MB)

Publication Notes: 

• We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
• This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

 Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

Citation

Pierce, Kenneth B. Jr.; Lookingbill, Todd; Urban, Dean.  2005.  A simple method for estimating potential relative radiation (PRR) for landscape-vegetation analysis..   Landscape Ecology. 20: 137-147