Effects of Forest Disturbance on Particulate Organic Matter Budgets of Small Streams

Abstract

Organic matter dynamics were studied in five streams at Coweeta Hydrologic Laboratory. Three of these streams drained logged watersheds, and two drained reference deciduous forest watersheds. Litter inputs to the streams draining disturbed watersheds were significantly lower than to reference streams. Additionally, while undisturbed litterfall consisted primarily of relatively refractory leaf species, litterfall in the disturbed watersheds was composed of more labile leaf material. Non-woody benthic organic material was generally lower in disturbed streams than in reference streams, and woody benthic material was substantially lower in disturbed streams. Particulate organic matter transport was measured intensively during storms. These data were used in a computer model to estimate annual particulate organic matter transport. The model was driven by empirical equations relating particulate concentration to the rate of increase in flow during storms, time since peak storm discharge, and average baseflow concentation. Results showed that disturbed streams exported significantly more particulate organic matter and that most of this transport occurred-during storms. In order to place our results in perspective, the model was also used to estimate transport over a 47-year period. Transport during our study was not significantly different from the long-term average. Organic matter budgets were calculated from input, standing crop, and export data. This synthesis showed that forest disturbance has increased export, has accelerated turnover of benthic particulate organic matter, and is depleting benthic material. These changes are related primarily to the decline of woody debris dams in the disturbed streams.

Emulation of natural disturbance (END) for riparian forest management: synthesis and recommendations

“…However, removal of riparian forest may adversely affect thermal regime (see reviews in Morash 2001, Steedman et al 2004), inputs of fine organic matter (Webster and Waide 1982, Webster et al 1990, Hartman et al 1996, and recruitment of coarse woody material (Dolloff and Webster 2000, Meleason et al 2003, Jones andDaniels 2008). Stream temperature typically is influenced by forest within 10 to 30 m of shorelines depending on tree height and canopy density (Barton et al 1985, Castelle et al 1994, Sridhar et al 2004, Wilkerson et al 2006).…”

STUDY THE EFFECT OF SALINITY AND NUTRIENTS FOR THE GROWTH OF Najas marina AND ITS IMPACT TO AQUATIC BIODIVERSITY IN MADU GANGA RAMSAR WETLAND IN SRI LANKA

“…One such concern is a decrease in water quality, which is generally reflected by increase of particulate matter in water body (Mullisset al, 1996;Webb and Walling, 1992). The composition and concentration of particulate matter in the aquatic environment is effected by the source and pathway of sediment input (Eisma, 1993;Webster et al, 1990).Results reveal that, mean turbidity value was 7.44 ± 3.8 NTU and a recorded turbidity value varies between 2.56 NTU to 23.0 NTU. Therefore, light penetration to bottom is very low.…”

Variation in Stream Water Quality in an Urban Headwater Stream in the Southern Appalachians

“…In many unimpaired streams, TSS typically begins to decrease before peak discharge and continues to decrease as the storm recedes (Glysson, 1987;Webster et al, 1990;Burke and MacDonald, 1999;Riedel et al, 2004). The REF stream responded in this manner but the URB and FOR streams did not.…”