10.5061/DRYAD.CNP5HQC3T
Chen, Dima
0000-0002-1687-0401
China Three Gorges University
Wang, Bing
Chinese Academy of Sciences
Wu, Ying
Yunnan University
Hu, Shuijin
North Carolina State University
Bai, Yongfei
Chinese Academy of Sciences
Legacy effect of grazing intensity mediates the bottom-up controls of
resource addition on soil food webs
Dryad
dataset
2020
bottom-up effect
environmental context
Functional groups
grazing intensities
historical grazing
resource addition
semi-arid grasslands
Soil food webs
Chinese National Key Development Program for Basic Research*
2016YFC0500804
National Natural Science Foundation of China
https://ror.org/01h0zpd94
31570450
National Natural Science Foundation of China
https://ror.org/01h0zpd94
31630010
Youth Innovation Promotion Association
https://ror.org/031141b54
2015061
Chinese National Key Development Program for Basic Research
2016YFC0500804
2020-12-22T00:00:00Z
2020-12-22T00:00:00Z
en
17150 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Large-scale studies have demonstrated that nitrogen (N) and water (W)
availability greatly affect terrestrial ecosystems worldwide, and this is
especially true for the resource-poor semi-arid grasslands. Yet,
experimental evidence is lacking for how N and W availability affect soil
food webs across historical grazing intensity-altered environments at a
local scale. 2. Here, we included N- and W-addition treatments in an
8-year grazing experiment (with four grazing intensities) to determine how
the legacy effects of grazing intensity mediate the responses of key
components of soil food webs (plants, microorganisms, and nematodes) to
resource addition in a semi-arid grassland. 3. After 4 years of N- and
W-addition treatments (with no grazing during that 4-year period), we
found that a legacy of grazing, even light grazing, had significant
negative effects on the components of plant community and soil food webs.
Both N and W addition increased above- and below-ground plant biomass,
especially under moderate and heavy grazing. N addition had negative
effects on the biomass of bacteria under no grazing, while W addition
increased the biomass of actinomycetes under light grazing. N addition
decreased the abundance of omnivorous + carnivorous nematodes under light
and heavy grazing, while W addition increased their abundance under heavy
grazing. Overall, the effects of resource addition on soil food webs
progressively decreased from the lowest trophic level (primary producers,
i.e., plants), to intermediate tropic levels (microorganisms and
root-feeding nematodes), to higher trophic levels (microbial-feeding
nematodes and omnivorous + carnivorous nematodes). 4. Synthesis and
applications. Our results, which are the first data concerning the effects
of resource addition on key components of soil food webs across a
historical grazing-induced environmental gradient, show that the strong
bottom-up controls of resource addition on soil food webs are mediated by
the legacy of grazing intensity. These finding should be useful for
predicting the responses of grassland ecosystems to future climate change
and suggest that the recovery of degraded grasslands will require more
than restoration measure of resource inputs alone.