首页|Belowground responses to altered precipitation regimes in two semi-arid grasslands

Belowground responses to altered precipitation regimes in two semi-arid grasslands

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  • NSTL
  • Elsevier
Predicted climate change extremes, such as severe or prolonged drought, may considerably impact carbon (C) and nitrogen (N) cycling in water-limited ecosystems. However, we lack a clear and mechanistic understanding of how extreme climate change events impact ecosystem processes belowground. This study investigates the effects of five years of reoccurring extreme growing season drought (66% reduction, extreme drought treatment) and two-month delay in monsoon precipitation (delayed monsoon treatment) on belowground productivity and biogeochemistry in two geographically adjacent semi-arid grasslands: Chihuahuan Desert grassland dominated by Bouteloua eriopoda and Great Plains grassland dominated by B. gracilis. After five years, extreme drought reduced belowground net primary productivity (BNPP) in the Chihuahuan Desert grassland but not in the Great Plains grassland. Across both grasslands, extreme drought increased soil pH and available soil nutrients nitrate and phosphate. The delayed monsoon treatment reduced BNPP in both grasslands. However, while available soil nitrate decreased in the Chihuahuan Desert grassland, the delayed monsoon treatment overall had little effect on soil ecosystem properties. Extreme drought and delayed monsoon treatments did not significantly impact soil microbial biomass, exoenzyme potentials, or soil C stocks relative to ambient conditions. Our study demonstrates that soil microbial biomass and exoenzyme activity in semi-arid grasslands are resistant to five years of extreme and prolonged growing season drought despite changes to soil moisture, belowground productivity, soil pH, and nutrient availability.

Extreme droughtPrecipitation seasonalityBelowground net primary productivityExtracellular enzymesMicrobial biomassSoil C and NSOIL MICROBIAL COMMUNITIESNORTH-AMERICAN MONSOONREGIONAL-SCALE DROUGHTCLIMATE VARIABILITYDRYLAND ECOSYSTEMSDESERT-GRASSLANDPULSE DYNAMICSWATER PULSESNITROGENCARBON

Holguin, Jennifer、Collins, Scott L.、McLaren, Jennie R.

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Univ Texas El Paso

Univ New Mex

2022

10.1016/j.soilbio.2022.108725

Soil Biology & Biochemistry

Soil Biology & Biochemistry

SCI
ISSN：0038-0717
年,卷(期)：2022.171
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