Premium
Scales of observation of riparian forests and distributions of suspended detritus in a prairie river
Author(s) -
JOHNSON SHERRI,
COVICH ALAN
Publication year - 1997
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1046/j.1365-2427.1997.00150.x
Subject(s) - riparian zone , detritus , environmental science , hydrology (agriculture) , streams , riparian forest , plant litter , benthic zone , large woody debris , litter , baseflow , organic matter , ecology , drainage basin , ecosystem , habitat , streamflow , geology , geography , biology , computer network , geotechnical engineering , computer science , cartography
1. Detrital inputs from riparian forests can provide the main source of energy to aquatic consumers in stream communities. However, the supply of coarse organic detritus to stream communities is difficult to predict. Patchy riparian inputs and connectivity between reaches have complicated studies and disrupted patterns of the distribution of suspended coarse particulate organic matter within streams and rivers. 2. In this study we emphasize the importance of spatial and temporal scales in determining potential distribution of instream leaf litter. Although large pulses of detritus are transported by streams during storm flows, the main supply of benthic leaf litter used by shredders and of suspended particulate organic matter used by filter feeders is transported during prolonged periods of baseflow. The local, fine‐scale distribution of this organic matter is determined by the location and continuity of leaf litter sources (riparian vegetation) and specific features of channel roughness (such as woody debris, roots and rocks). 3. Viewing riparian vegetation at several scales results in variable conclusions regarding the amount of potential source area of leaf detritus. The percentage of suspended whole leaves at sites in the Little Washita River, Oklahoma, U.S.A. was best explained by the percentage of riparian forest cover in 500 m and 1000 m reaches upstream of the sites, as viewed by remote sensing imagery. The amount of leaf fragments was best explained by distance downstream along the longitudinal gradient. Ash‐free dry mass of suspended coarse particulate matter did not correlate with any measures of riparian cover. 4. Our results suggest that leaves originate over longer reach lengths than those generally considered as source areas. Scale is an important consideration in studies of riparian patterns and related instream processes because of the need to integrate point dynamics as well as upstream influences.