Plant traits in influencing soil moisture in semiarid grasslands of the Loess Plateau, China

Qindi Zhang; Wei Wei; Liding Chen; Lei Yang; Yiqi Luo; Andong Cai

doi:10.1016/j.scitotenv.2020.137355

Plant traits in influencing soil moisture in semiarid grasslands of the Loess Plateau, China

Sci Total Environ. 2020 May 20:718:137355. doi: 10.1016/j.scitotenv.2020.137355. Epub 2020 Feb 15.

Authors

Qindi Zhang¹, Wei Wei², Liding Chen³, Lei Yang³, Yiqi Luo⁴, Andong Cai⁵

Affiliations

¹ College of Life Sciences, Shanxi Normal University, Linfen 041000, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, USA.
² State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: weiwei@rcees.ac.cn.
³ State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
⁴ Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, USA.
⁵ Key Laboratory for Agro-Environment, Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 10081, China.

PMID: 32088487
DOI: 10.1016/j.scitotenv.2020.137355

Abstract

Large-scale vegetation restoration projects pose threats to water resource security in water-limited regions. Thus, the quantification of how vegetation cover affects soil moisture is of key importance to support effective restoration schemes in drylands. However, the current understanding of such effects remains poor. For this study, an in-situ vegetation-removal experiment was conducted at 36 herbaceous grassland sites having different community compositions and topographical conditions in two adjacent loess watersheds of the Loess Plateau, China. The effects of vegetation cover (vegetation effects) on soil moisture were analyzed across soil profiles (0-180 cm) and two growing seasons. Overall, 13 plant traits and 7 topographic and soil properties were employed to evaluate how community compositions modulated vegetation effects on soil moisture. The results showed that vegetation cover increased soil moisture in the surface layer (0-20 cm) by 6.81% during wet periods (semi-monthly rainfall >30 mm) relative to an in-situ unvegetated control, but primarily induced a decline of soil moisture in the deep soil layer (20-180 cm) by 19.44% across two growing seasons. Redundancy analysis (RDA) and structural equation modeling (SEM) suggested that these vegetation effects on soil moisture were significantly correlated with vegetative height, leaf area, shallow root allocation, and slope gradient. Our study revealed that tall, small-leaved, and shallow-rooted plants on flat topographies were beneficial to soil water retention and replenishment. This implied that current restoration strategies may be significantly improved through the development of optimal communities and diverse terracing measures. Our findings are anticipated to provide effective guidance for soil water conservation, as well as ecosystem rehabilitation in dry and degraded regions.

Keywords: Beneficial community structure; Functional traits; Loess Plateau; Semiarid grasslands; Soil moisture; Vegetation removal.

MeSH terms

China
Grassland*
Plants
Soil*

Substances

Soil