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Harvard Forest REU Symposium Abstract 2005
- Title: Effects of Selective Logging on microclimate and Coarse Woody Debris (CWD) in a Northern Temperate Forest
- Author: Linh Vuong (University of Puget Sound)
- Abstract:
Understanding the effects of selective logging on CWD respiration and sequestration is critical to assessing the contribution of CWD on ecosystem carbon balance. To quantify the effects of selective logging on microclimatic conditions, we installed an automated system developed by Dan Curran in the selectively logged Simmes tract and a maturing Harvard forest plot. Over the course of the 2005 growing season, we made continuous measurements of temperature for three CWD decay classes, air temperature, soil temperature, short-wave radiation, relative humidity, and routine manual measurements of CWD moisture. Log temperatures and air temperature were significantly higher in selectively harvested forest (p<0.01). From the greater difference in log temperature than air temperature, between the cut site and the control site, we infer that higher short-wave radiation entering the thinner canopy contributes to the warmer conditions observed in the logged plot. The control site had substantially higher relative humidity, wood moisture, and soil moisture than the cut site (p<0.01). Decay class 3 was also significantly wetter than Decay class 1 within both sites (Figure 1). Applying Wendy Liu’s CWD respiration model, CWD Respiration=exp(a+b+ln(Moisture)+C(Temp)) to our data (Figure 2), we discovered higher CWD temperatures correspond to higher respiration rates in the cut site even though the CWD was drier, suggesting that CWD in the cut site was losing carbon more rapidly than the control site under the microclimatic conditions observed this summer. CWD was not dry enough in the cut site to offset the difference in temperature between the sites.
- Research Category:
