Watershed and Streamside Management Zone Characterization in the Allegheny Plateau of West Virginia

Abstract

The Streamside Management Zone (SMZ) is a cornerstone of forestry Best Management Practices to protect streamwater quality from non-point source pollution resulting from silvicultural operations. However, the exact width and harvest intensity of SMZs that best protects water quality while allowing for commercially valuable timber harvesting has not been determined. The long-term objective of this study is to characterize SMZs and watersheds before and after harvest with different SMZ widths and harvesting intensities in the Allegheny Plateau of West Virginia. The objective this paper is to present the pre-harvest SMZ and watershed characterization. Each of the watershed SMZs were characterized pre-harvest in terms of vegetation, water, soil, carbon, and monetary value within SMZs to predict how silvicultural treatments will affect the future stands. The major overstory tree species found are Acer saccharum, Liriodendron tulipifera, Fagus grandifolia, Tilia americana, Betula lenta, snags, Betula lutea, Fraxinus spp., and Acer rubrum. The overall average streamwater temperature is 13°C. Highest daily temperature occurred in the mid-afternoon and lowest temperatures occurred just before sunrise. Streamwater quality was good, with near neutral pH, low nitrogen content, and high dissolved oxygen. USLE erosion estimates predicted an erosion rate of 2.9 Mg/ha/yr in the SMZ. However, the sediment rods showed an overall accumulation of soil in the SMZ, averaging 173 Mg/ha/yr. This equates to an average watershed loss of 10.9 Mg/ha/yr. In-stream and SMZ LWD volume was approximately equal at 28 and 33 m3/ha. Large woody debris was more decayed in the SMZ than in-stream LWD.