Poster Details
ABUNDANCE, DISTRIBUTION, AND GEOMETRY OF NATURALLY OCCURRING MACROPORES IN STREAM BANKS
Macropores are a type of preferential flow path where conduit-like voids exist in soil. They form by biological processes, erosive action in subsurface flow, or soil cracking. They can increase the flow of water in stream banks and may affect riparian transport of nutrients and pollutants, yet their geographic distribution is unknown. We examined the distribution, abundance, and geometry of naturally occurring macropores in the banks of 20 streams across five physiographic provinces in the eastern USA. Macropores were present in all 20 streams despite variations in physiographic province, stream order, and soil texture. However, macropore distribution, abundance, and geometry varied among streams, with soil texture having the greatest influence. For example, soils primarily containing silt and clay had more macropores than soils consisting of sand or gravel, possibly due to differences in soil cohesiveness and/or hydraulic conductivity. This work represents the first attempt to characterize macropores across a variety of riverine systems and presents evidence that macropores may play an important role in hyporheic exchange within stream banks.
Amiana McEwen (Primary Presenter/Author,Co-Presenter/Co-Author), Virginia Tech, amcewen@vt.edu;
Erich Hester (Co-Presenter/Co-Author), Virginia Tech, ehester@vt.edu;