Hydrologic influences on leaf decomposition in a channel and adjacent bank of a gallery forest stream

TitleHydrologic influences on leaf decomposition in a channel and adjacent bank of a gallery forest stream
Publication TypeJournal Article
Year of Publication1988
AuthorsGurtz, ME, Tate, CM
JournalThe American Midland Naturalist
Pagination11 -21
Accession NumberKNZ00178
Keywordsgallery forest

Hydrologic extremes of flooding and drought typically occur each year in prairie streams. Two experiments were conducted in a fifth- order, gallery forest reach of King's Creek, Kansas, to assess the effect of hydrologic conditions on decomposition of leaves in the stream channel and on the adjacent floodplain. Temporal patterns of weight loss were examined in the first experiment. Leaves of bur oak and hackberry decomposed more rapidly in the channel than on the adjacent bank. A sharp drop in percent remaining for hackberry in the 2nd month (mid- December to mid-January) coincided with a period of high shredder densities on hackberry leaves. On the bank, decomposition of hackberry leaves was fastest during intervals that included one or more inundations of the leaf packs. Bur oak leaves decomposed more slowly than hackberry leaves and were influenced less by the hydrologic history. In the second experiment, spatial variation in decomposition rate of hackberry leaves was examined by placing 20 pairs of leaf packs in a transect extending from the center of the stream channel on the top of the upper bank. Position on the transect affected the frequency and duration of inundations on the floodplain, which ranged from one (minimum of 0.2 hr) to 17 times (272 cumulative hr under water), while three pairs of packs in the channel were always under water. The logarithm of percent remaining after 274 days was significantly correlated with number of hours inundated and number of times inundated, although other factors such as soil moisture or amount of flood-deposited silt may have influenced differences in decomposition rates along the transect. We concluded that flood frequency, during and timing affected both spatial and temporal patterns of decomposition, especially of a fast-decomposing species, in the riparian forest of an intermittent prairie stream