Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Ayron M. Strauch; Richard A. Mackenzie; Gregory L. Bruland; Ralph Tingley; Christian P. Giardina
    Date: 2014
    Source: Journal of Environmental Quality. 43(4): 1475-1483
    Publication Series: Scientific Journal (JRNL)
    Station: Pacific Southwest Research Station
    PDF: View PDF  (1.71 MB)


    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.

    Publication Notes

    • You may send email to 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.


    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.


    Google Scholar

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page