The Relative Roles of Temperature and Macroinvertebrates in the Processing of Leaf Litter in a Warm-Water Texas Stream
Smith, Stephen Lee
Previous studies of leaf litter processing rates in Texas streams have shown that rapid processing occurs despite the apparent lack of a "typical" shredder fauna. Presumably the higher water temperatures in these streams are the primary factor responsible for the rapid processing. However, an alternative may be the existence of "non-typical" shredders. To test the relative effects of macroinvertebrate community and water temperature, the processing of Celtis laevigata leaves was studied in Honey Creek, Texas, a heavily canopied first order, spring-fed stream. Leaf pack experiments conducted during November-January yielded a processing rate (-k=0.083) which was significantly slower (P=0.0001) than for identical experiments conducted during June-August (-k=O. 124). When expressed on a per degree-day bas is, there was no significant difference (P=0.898) between the processing rates, thus demonstrating the dominating effect of temperature. It is hypothesized that leaf processing in such streams results mainly from microbial activities in the absence of a "typical" shredder community.
stream ecology, Honey Creek, freshwater invertebrates, microbial respiration
Smith, S.L. (1984). The relative roles of temperature and macroinvertebrates in the processing of leaf litter in a warm-water Texas stream (Unpublished thesis). Southwest Texas State University, San Marcos, Texas.