Plant community composition alters moisture and temperature sensitivity of soil respiration in semi-arid shrubland
- 18 June 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Oecologia
- Vol. 197 (4), 1003-1015
- https://doi.org/10.1007/s00442-021-04961-4
Abstract
Soil respiration (Rs) is the second largest carbon (C) flux to the atmosphere and our understanding of how Rs and its components shift with plant-community composition remains an important question. We used high-frequency soil respiration measurements and root exclusion to evaluate how Rs, autotrophic respiration (Ra) and heterotrophic respiration (Rh) vary between a semi-arid perennial shrub community and annual invasive community. Over two growing seasons, total Rs was 40% higher under annual vegetation compared to shrubs. Partitioning revealed consistently higher Ra under annual vegetation which accounted for most of the difference in Rs. Under annual vegetation, Ra increased soon after the first rain events and remained high despite cooling temperatures while shrub Ra increased only when soil temperature began to warm up. The Rh rates were similar between vegetation types when daily soil temperatures were lower than 20 °C. As soil temperatures increased and soil moisture dropped below 10%, Rh was consistently higher under annual vegetation than shrubs. Seasonal dynamics of Rs and Rh were best modeled with an interaction term between soil moisture and temperature with significantly different model parameters for each vegetation type. Differences in the timing and magnitude of Rs and Ra between vegetation types are consistent with phenological differences between shrubs and annuals. Under annuals, larger Rh at high temperatures suggests that expansion of annual vegetation and future hotter and drier conditions could lead to greater C losses from this semi-arid shrub system.Keywords
This publication has 76 references indexed in Scilit:
- Grass Invasions Across a Regional Gradient are Associated with Declines in Belowground Carbon PoolsEcosystems, 2012
- Effects of soil moisture on the temperature sensitivity of heterotrophic respiration vary seasonally in an old‐field climate change experimentGlobal Change Biology, 2011
- Climate change and the invasion of California by grassesGlobal Change Biology, 2011
- Priming effects: Interactions between living and dead organic matterSoil Biology and Biochemistry, 2010
- Frontiers and challenges in soil respiration research: from measurements to model-data integrationBiogeochemistry, 2010
- Does photosynthesis affect grassland soil‐respired CO2 and its carbon isotope composition on a diurnal timescale?New Phytologist, 2009
- Soil Respiration in European Grasslands in Relation to Climate and Assimilate SupplyEcosystems, 2008
- Stability of exotic annual grasses following restoration efforts in southern California coastal sage scrubJournal of Applied Ecology, 2008
- Precision and accuracy of three alternative instruments for measuring soil water content in two forest soils of the Pacific NorthwestCanadian Journal of Forest Research, 2005
- Water pulses and biogeochemical cycles in arid and semiarid ecosystemsOecologia, 2004