- Award ID(s):
- Publication Date:
- NSF-PAR ID:
- Journal Name:
- Applied and Environmental Microbiology
- Sponsoring Org:
- National Science Foundation
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Bark decomposition in white oak soil outperforms eastern hemlock soil, while bark type leads to consistent changes in soil microbial compositionAbstract Bark decomposition is an underexamined component of soil carbon cycling and soil community assembly. Numerous studies have shown faster decomposition of leaf litter in “home” environments (i.e. within soil adjacent to the plant that produced the leaves), suggesting potential legacy effects from previous deposition of similar litter. This is expected to occur through, in part, accumulation of microorganisms that metabolize substrates the litter provides. Whether a similar “home-field advantage” (HFA) exists for bark decomposition is unknown, but this dynamic may differ because annual bark deposits to soil are minimal relative to leaf deposits. We hypothesized that (1) as with leaf litter, bark will be better decomposed near to the tree from which it was collected, and (2) that decomposing bark can initiate change in soil microbial composition. To test these hypotheses, we used a full factorial design that included two bark types (collected from eastern hemlock, Tsuga canadensis , and white oak, Quercus alba ) and two soil types (‘home’ and ‘away’) within a temperate mixed hardwood forest at the Shale Hills Catchment in central Pennsylvania, USA. Bark was excised from 25 replicates of each tree type, buried in either home or away soil, and incubated belowground from Julymore »
Long-term nitrogen deposition enhances microbial capacities in soil carbon stabilization but reduces network complexity
Anthropogenic activities have increased the inputs of atmospheric reactive nitrogen (N) into terrestrial ecosystems, affecting soil carbon stability and microbial communities. Previous studies have primarily examined the effects of nitrogen deposition on microbial taxonomy, enzymatic activities, and functional processes. Here, we examined various functional traits of soil microbial communities and how these traits are interrelated in a Mediterranean-type grassland administrated with 14 years of 7 g m−2year−1of N amendment, based on estimated atmospheric N deposition in areas within California, USA, by the end of the twenty-first century.
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Soil microbial communities were significantly altered by N deposition. Consistent with higher aboveground plant biomass and litter, fast-growing bacteria, assessed by abundance-weighted average rRNA operon copy number, were favored in N deposited soils. The relative abundances of genes associated with labile carbon (C) degradation (e.g.,
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