Controls on the rate of COSubscript2/Subscript

Authors: M Vanderhoof C Williams M Pasay B Ghimire

Publish Date: 2012/11/13

Volume: 114, Issue: 1-3, Pages: 299-311

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Abstract

The rate at which CO2 is released from woody debris postclearcut affects the long term carbon consequences of such disturbances Changes in microclimate postclearcut may alter the rate of woody debris decomposition from that in a mature forest However very few studies have explored postdisturbance rates of woody debris respiration and the possible influence of an altered microclimate and even fewer have considered the role of log position in influencing rates of respiration This study explored the effects of log position and microclimate variability on the rates of coarse woody debris CWD respiration The rates of respiration of downed Norway spruce Picea abies logs were repeatedly measured in situ using an LI6200 gas analyzer Treatments included native logs in the clearcut site native logs in a neighboring mature spruce stand and logs transferred from the clearcut site to the mature spruce stand The transfer logs showed the highest rates of respiration 044 ± 003 g CO2 m−2 log surface h−1 followed by the clearcut logs 036 ± 002 g CO2 m−2 log surface h−1 and spruce stand logs 030 ± 002 g CO2 m−2 log surface h−1 P  001 The boost in respiration found in the transfer treatment group was best explained by increases in log water content while the slower rate of respiration in the spruce stand logs was best explained by the log’s contact/noncontact with the ground prior to the start of the observational campaign CWD respiration was found to represent 18 ± 3  of total daytime ecosystem respiration R ecoWe thank Mark VanScoy and Aaron Ellison of the Harvard Forest LTER for their assistance with equipment as well as Katharine Chute and Marcus Pasay for their long hours in the field and David Hibbett of Clark Biology for assistance identifying fungi We also thank the anonymous reviewers for their helpful comments on previous versions of this manuscript This work was funded by Clark University as well as the 2010–2011 Albert Norma and Howard Geller ‘77 Endowed Research Awards for Projects Relating to Sustainability administered by the George Perkins Marsh Institute of Clark University This work was also supported by the National Science Foundation Award 0620443 Research Experience for Undergraduates Site award to the Harvard Forest LTER

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