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Title: SOM density fractions beneath trees of different mycorrhizal types in New England forests
Recent work suggests mycorrhizal fungi are important drivers of soil organic matter dynamics; however, whether this is a result of the fungi themselves or related traits of their host trees remains unclear. We evaluated how tree mycorrhizal associations and foliar chemistry influence mineral-associated organic matter (MAOM) and particulate organic matter (POM) in temperate forests of northern New England, USA. We measured carbon (C) and nitrogen (N) concentrations and C:N of three soil density fractions beneath six tree species that vary in both mycorrhizal association and foliar chemistry. We found a significant decline in the concentration of MAOM C and N with increasing foliar C:N in soil beneath tree species with arbuscular mycorrhizal (AM), but not ectomycorrhizal (ECM) fungi. The C:N of POM and MAOM was positively associated with the foliar C:N of the dominant tree species in a forest, and MAOM C:N was also higher beneath ECM- rather than AM-associated tree species. These results add to the growing body of support for mycorrhizal fungi as predictors of soil C and N dynamics, and suggest that C concentration in the MAOM fraction is more sensitive to organic matter chemistry beneath AM-associated tree species. Because MAOM decomposition is thought to be less responsive than POM decomposition to changes in soil temperature and moisture, differences in the tendency of AM- vs. ECM-dominated forests to support MAOM formation and persistence may lead to systematic differences in the response of these forest types to ongoing climate change. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.  more » « less
Award ID(s):
1637685
NSF-PAR ID:
10317028
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Environmental Data Initiative
Date Published:
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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