Differential responses of grassland community nonstructural carbohydrate to experimental drought along a natural aridity gradient

Lin Song; Wentao Luo; Robert J Griffin-Nolan; Wang Ma; Jiangping Cai; Xiaoan Zuo; Qiang Yu; Henrik Hartmann; Mai-He Li; Melinda D Smith; Scott L Collins; Alan K Knapp; Zhengwen Wang; Xingguo Han

doi:10.1016/j.scitotenv.2022.153589

Differential responses of grassland community nonstructural carbohydrate to experimental drought along a natural aridity gradient

Sci Total Environ. 2022 May 20:822:153589. doi: 10.1016/j.scitotenv.2022.153589. Epub 2022 Feb 2.

Authors

Lin Song¹, Wentao Luo², Robert J Griffin-Nolan³, Wang Ma¹, Jiangping Cai⁴, Xiaoan Zuo⁵, Qiang Yu⁶, Henrik Hartmann⁷, Mai-He Li⁸, Melinda D Smith⁹, Scott L Collins¹⁰, Alan K Knapp⁹, Zhengwen Wang¹¹, Xingguo Han¹

Affiliations

¹ Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
² Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. Electronic address: wentaoluo@iae.ac.cn.
³ Department of Biology, Syracuse University, Syracuse, NY 13244, USA.
⁴ Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
⁵ Urat Desert-Grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China.
⁶ National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
⁷ Max-Planck Institute for Biogeochemistry, Hans Knoll Str. 10, 07745 Jena, Germany.
⁸ Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf CH-8903, Switzerland; Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
⁹ Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, USA.
¹⁰ Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
¹¹ Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. Electronic address: wangzw@iae.ac.cn.

PMID: 35122840
DOI: 10.1016/j.scitotenv.2022.153589

Abstract

Plant nonstructural carbohydrates (NSC) can reflect community and ecosystem responses to environmental changes such as water availability. Climate change is predicted to increase aridity and the frequency of extreme drought events in grasslands, but it is unclear how community-scale NSC will respond to drought or how such responses may vary along aridity gradients. We experimentally imposed a 4-year drought in six grasslands along a natural aridity gradient and measured the community-weighted mean of leaf soluble sugar (SS_CWM) and total leaf NSC (NSC_CWM) concentrations. We observed a bell-shape relationship across this gradient, where SS_CWM and total NSC_CWM concentrations were lowest at intermediate aridity, with this pattern driven primarily by species turnover. Drought manipulation increased both SS_CWM and total NSC_CWM concentrations at one moderately arid grassland but decreased total NSC_CWM concentrations at one moist site. These differential responses to experimental drought depended on the relative role of species turnover and intraspecific variation in driving shifts in SS_CWM and total NSC_CWM concentrations. Specifically, the synergistic effects of species turnover and intraspecific variation drove the responses of leaf NSC concentrations to drought, while their opposing effects diminished the effect of drought on plant SS_CWM and total NSC_CWM concentrations. Plant resource strategies were more acquisitive, via higher chlorophyll_CWM concentration, to offset reduced NSC_CWM concentrations and net aboveground primary productivity (ANPP) with increasing aridity at more mesic sites, but more conservative (i.e., decreased plant height_CWM and ANPP) to reduce NSC consumption at drier sites. The relationship between water availability and NSC_CWM concentrations may contribute to community drought resistance and improve plant viability and adaptation strategies to a changing climate.

Keywords: Aridity gradient; Climate extremes; Drought; Grasslands; Intraspecific variability; Nonstructural carbohydrates; Species turnover.

MeSH terms

Climate Change
Dietary Carbohydrates
Droughts*
Ecosystem
Grassland*

Substances

Dietary Carbohydrates