You are here: Home
/ Publication Information
Title: Climate change and land use drivers of fecal bacteria in tropical Hawaiian rivers
Author: Strauch, Ayron M.; Mackenzie, Richard A.; Bruland, Gregory L.; Tingley, Ralph; Giardina, Christian P.;
Source: Journal of Environmental Quality. 43(4): 1475-1483
Publication Series: Scientific Journal (JRNL)
Description: Potential shifts in rainfall driven by climate change are anticipated to affect watershed processes (e.g., soil moisture, runoff, stream flow), yet few model systems exist in the tropics to test hypotheses about how these processes may respond to these shifts. We used a sequence of nine watersheds on Hawaii Island spanning 3000 mm (7500–4500 mm) of mean annual rainfall (MAR) to investigate the effects of short-term (24-h) and long-term (MAR) rainfall on three fecal indicator bacteria (FIB) (enterococci, total coliforms, and Escherichia coli). All sample sites were in native Ohia dominated forest above 600 m in elevation. Additional samples were collected just above sea level where the predominant land cover is pasture and agriculture, permitting the additional study of interactions between land use across the MAR gradient. We found that declines in MAR significantly amplified concentrations of all three FIB and that FIB yield increased more rapidly with 24-h rainfall in low-MAR watersheds than in high-MAR watersheds. Because storm frequency decreases with declining MAR, the rate of change in water potential affects microbial growth, whereas increased rainfall intensity dislodges more soil and bacteria as runoff compared with water-logged soils of high-MAR watersheds. As expected, declines in % forest cover and increased urbanization increased FIB. Taken together, shifts in rainfall may alter bacterial inputs to tropical streams, with land use change also affecting water quality in streams and nearshore environments.
- 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.
XML: View XML
Strauch, Ayron M.; Mackenzie, Richard A.; Bruland, Gregory L.; Tingley, Ralph; Giardina, Christian P. 2014. Climate change and land use drivers of fecal bacteria in tropical Hawaiian rivers. Journal of Environmental Quality. 43(4): 1475-1483.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility