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Riparian plant composition along hydrologic gradients in a dryland river basin and implications for a warming climate
Author(s) -
Reynolds Lindsay V.,
Shafroth Patrick B.
Publication year - 2017
Publication title -
ecohydrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.982
H-Index - 54
eISSN - 1936-0592
pISSN - 1936-0584
DOI - 10.1002/eco.1864
Subject(s) - perennial stream , riparian zone , environmental science , hydrology (agriculture) , streamflow , perennial plant , plant community , ecohydrology , arid , drainage basin , streams , ecosystem , ecology , species richness , habitat , geography , geology , geotechnical engineering , cartography , biology , computer network , computer science
Droughts in dryland regions on all continents are expected to increase in severity and duration under future climate projections. In dryland regions, it is likely that minimum streamflow will decrease with some perennial streams shifting to intermittent flow under climate‐driven changes in precipitation and runoff and increases in temperature. Decreasing base flow and shifting flow regimes from perennial to intermittent could have significant implications for stream‐dependent biota, including riparian vegetation. In this study, we asked, how do riparian plant communities vary along wet‐to‐dry hydrologic gradients on small (first–third order) streams? We collected data on geomorphic, hydrologic, and plant community characteristics on 54 stream sites ranging in hydrology from intermittent to perennial flow across the Upper Colorado River Basin (284,898 km 2 ). We found that plant communities varied along hydrologic gradients from high to low elevation between streams, and perennial to intermittent flow. We identified indicator species associated with different hydrologic conditions and suggest how plant communities may shift under warmer, drier conditions. Our results indicate that species richness and cover of total, perennial, wetland, and native plant groups will decrease while annual plants will increase under drying conditions. Understanding how plant communities respond to regional drivers such as hydroclimate requires broad‐scale approaches such as sampling across whole river basins. With increasingly arid conditions in many regions of the globe, understanding plant community shifts is key to understanding the future of riparian ecosystems.