TY - JOUR
T1 - Soil Water Availability Drives Changes in Community Traits Along a Hydrothermal Gradient in Loess Plateau Grasslands
AU - Zhang, Qindi
AU - Wei, Wei
AU - Chen, Liding
AU - Yang, Lei
AU - Chen, Han Y.H.
AU - Luo, Yiqi
N1 - Funding Information:
This work was supported by the National Key Research and Development Program of China (2016YFC0501701), National Natural Science Foundation of China (41601027, 41390462), and Distinguished Membership of the Youth Innovation Promotion Association of CAS.
Publisher Copyright:
© 2019 The Society for Range Management
PY - 2020/3
Y1 - 2020/3
N2 - Plant functional traits can be used to predict ecosystem responses to climate gradients, yet precipitation explains very little variation for most traits. Soil water availability directly influences plant water uptake and thus may assist with the improvement of plant trait–water relationships. However, this promise remains poorly realized due to rare tests. Here, we provide the first study that attempts to link climate factors, vertical soil water availability, and community composition at a regional scale. Our study paired field-measured vertical soil available water (0–300 cm) and community functional composition at 46 herbaceous grassland sites along a steep hydrothermal gradient in the Loess Plateau of Central China. Community functional composition was expressed via community-weighted means of eight traits. Structural equation modeling was employed to evaluate the role of vertical soil available water content, controlled by precipitation and air temperature, in affecting plant community-weighted traits. We found that soil available water content at depths of 20–100 cm was typically responsible for mediating the effects of precipitation and air temperature on plant community composition. This emerged as the predominant factor to explain variations in grassland response traits, including leaf area, specific leaf area, and leaf dry matter content. These traits exhibited clear drought-induced shifts along soil desiccation gradients and responded to drier conditions by reducing leaf area/specific leaf area and increasing leaf dry matter content. Our findings rehighlighted soil water availability as the core driver that needs to be considered in the restoration and management of dryland ecosystems.
AB - Plant functional traits can be used to predict ecosystem responses to climate gradients, yet precipitation explains very little variation for most traits. Soil water availability directly influences plant water uptake and thus may assist with the improvement of plant trait–water relationships. However, this promise remains poorly realized due to rare tests. Here, we provide the first study that attempts to link climate factors, vertical soil water availability, and community composition at a regional scale. Our study paired field-measured vertical soil available water (0–300 cm) and community functional composition at 46 herbaceous grassland sites along a steep hydrothermal gradient in the Loess Plateau of Central China. Community functional composition was expressed via community-weighted means of eight traits. Structural equation modeling was employed to evaluate the role of vertical soil available water content, controlled by precipitation and air temperature, in affecting plant community-weighted traits. We found that soil available water content at depths of 20–100 cm was typically responsible for mediating the effects of precipitation and air temperature on plant community composition. This emerged as the predominant factor to explain variations in grassland response traits, including leaf area, specific leaf area, and leaf dry matter content. These traits exhibited clear drought-induced shifts along soil desiccation gradients and responded to drier conditions by reducing leaf area/specific leaf area and increasing leaf dry matter content. Our findings rehighlighted soil water availability as the core driver that needs to be considered in the restoration and management of dryland ecosystems.
KW - community-weighted means
KW - Loess Plateau
KW - plant functional traits
KW - soil available water
KW - water availability
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U2 - 10.1016/j.rama.2019.10.012
DO - 10.1016/j.rama.2019.10.012
M3 - Article
AN - SCOPUS:85075865361
SN - 1550-7424
VL - 73
SP - 276
EP - 284
JO - Rangeland Ecology and Management
JF - Rangeland Ecology and Management
IS - 2
ER -