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Title: Predator contributions to belowground responses to warming

Identifying the factors that control soil CO2 emissions will improve our ability to predict the magnitude of climate change–soil ecosystem feedbacks. Despite the integral role of invertebrates in belowground systems, they are excluded from climate change models. Soil invertebrates have consumptive and nonconsumptive effects on microbes, whose respiration accounts for nearly half of soil CO2 emissions. By altering the behavior and abundance of invertebrates that interact with microbes, invertebrate predators may have indirect effects on soil respiration. We examined the effects of a generalist arthropod predator on belowground respiration under different warming scenarios. Based on research suggesting invertebrates may mediate soil CO2 emission responses to warming, we predicted that predator presence would result in increased emissions by negatively affecting these invertebrates. We altered the presence of wolf spiders (Pardosa spp.) in mesocosms containing a forest floor community. To simulate warming, we placed mesocosms of each treatment in ten open-top warming chambers ranging from 1.5° to 5.5°C above ambient at Harvard Forest, Massachusetts, USA. As expected, CO2 emissions increased under warming and we found an interactive effect of predator presence and warming, although the effect was not consistent through time. The interaction between predator presence and warming was the inverse ofmore » our predictions: Mesocosms with predators had lower respiration at higher levels of warming than those without predators. Carbon dioxide emissions were not significantly associated with microbial biomass. Here, we did not find evidence of consumptive effects of predators on the invertebrate community, suggesting that predator presence mediates response of microbial respiration to warming through nonconsumptive means. In our system, we found a significant interaction between warming and predator presence that warrants further research into mechanism and generality of this pattern to other systems.« less
Authors:
 [1] ;  [1]
  1. Bowling Green State Univ., Bowling Green, OH (United States)
Publication Date:
OSTI Identifier:
1326709
Grant/Contract Number:
FG02-08ER64510
Type:
Published Article
Journal Name:
Ecosphere
Additional Journal Information:
Journal Volume: 7; Journal Issue: 9; Journal ID: ISSN 2150-8925
Publisher:
Ecological Society of America
Research Org:
North Carolina State Univ., Raleigh, NC (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; brown food web; carbon; climate change; invertebrate; predator; soil respiration; warming