Detecting changes in riparian habitat conditions based on patterns of greenness change: a case study from the upper San Pedro River Basin, USAAuthor(s): K. Bruce Jones; Curtis E. Edmonds; E. Terrance Slonecker; James D. Wickham; Anne C. Neale; Timothy G. Wade; Kurt H. Riitters; William G. Kepner
Source: Ecological Indicators, Vol. 8: 89-99
Publication Series: Miscellaneous Publication
PDF: Download Publication (1.04 MB)
Healthy riparian ecosystems in arid and semi-arid regions exhibit shifting patterns of vegetation in response to periodic flooding. Their conditions also depend upon the amount of grazing and other human uses. Taking advantage of these system properties, we developed and tested an approach that utilizes historical Landsat data to track changes in the patterns of greenness (Normalized Difference Vegetation Index) within riparian zones. We tested the approach in the Upper San Pedro River of southeastern Arizona of the US, an unimpounded river system that flows north into the US from northern Mexico. We evaluated changes in the pattern of greenness in the San Pedro River National Conservation Area (SPRNCA), an area protected from grazing and development since 1988, and in a relatively unprotected area north of the SPRNCA (NA). The SPRNCA exhibited greater positive changes in greenness than did the NA. The SPRNCA also exhibited larger, more continuous patches of positive change than did the NA. These pattern differences may reflect greater pressures from grazing and urban sprawl in the NA than in the SPRNCA, as well as differences in floodplain width, depth to ground water, and base geology. The SPRNCA has greater amounts of ground and surface water available to support a riparian gallery forest than does the NA, and this may have influenced changes during the study period.
Estimates of the direction of greenness change (positive or negative) from satellite imagery were similar to estimates derived from aerial photography, except in areas where changes were from one type of shrub community to another, and in areas with agriculture. Change estimates in these areas may be more difficult because of relatively low greenness values, and because of differences in soil moisture, sun-angle, and crop rotations among the dates of data collection. The potential for applying a satellite-based, greenness change approach to evaluate riparian ecosystem condition over broad geographic areas is also discussed.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- 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.
CitationJones, K. Bruce; Edmonds, Curtis E.; Slonecker, E. Terrance; Wickham, James D.; Neale, Anne C.; Wade, Timothy G.; Riitters, Kurt H.; Kepner, William G. 2008. Detecting changes in riparian habitat conditions based on patterns of greenness change: a case study from the upper San Pedro River Basin, USA. Ecological Indicators, Vol. 8: 89-99
Keywordsgreenness change, NDVI, riparian ecosystems
- Quantifying the effects of overgrazing on mountainous watershed vegetation dynamics under a changing climate
- Detection of the Coupling between Vegetation Leaf Area and Climate in a Multifunctional Watershed, Northwestern China
- Combined effects of climate and land management on watershed vegetation dynamics in an arid environment
XML: View XML