Investigation of Factors Controlling the Regional-Scale Distribution of Dried Soil Layers Under Forestland on the Loess Plateau,China |
| |
| Authors: | Yunqiang Wang Ming’an Shao Zhipeng Liu David N Warrington |
| |
| Institution: | (1) Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China;(2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, 712100, China;(3) Graduate University of Chinese Academy of Sciences, Beijing, 100049, China; |
| |
| Abstract: | The effects of drought on plants have been extensively documented in water-limited systems. However, its effects on soil are
seldom considered because of the lack of comparative data on profile soil water content (SWC). A dried soil layer (DSL) within
the soil profile is a typical indication of soil drought caused by climate change and/or ill-advised human practices. The
regional spatial variability, dominant factors, and predictive models of DSL under forestland were explored in the present
study. SWC at 0–600 cm of 125 pre-selected sites across the entire Loess Plateau was measured, and then two evaluation indices
of DSL (the thickness of DSL, DSLT; SWC within the DSL, DSL–SWC) were calculated. The corresponding soil, topography, plant,
and meteorology factors (a total of 28 variables) for each site were also measured. Most of the forestlands across the Plateau
had DSL formation within the soil profile (102 of 125 study sites). The DSL levels were considered to be serious, with DSLT
generally exceeding 300 cm with a mean DSL–SWC of only 7.9% (field capacity (FC) = 18.1%). DSLT and DSL–SWC indicated a moderate
and strong spatial dependence with ranges of 69 and 513 km, respectively. Thicker DSLs were mainly distributed in the center
of the Plateau, whereas thinner DSLs were observed in the southern and southeastern parts. In contrast, DSL–SWC distributions
demonstrated an obvious decreasing trend from the southeast to the northwest. Dominant factors affecting DSLT under forestlands
were FC, bulk density, slope gradient, slope aspect, and capillary water content; while dominant factors for DSL–SWC were
FC, aridity, sand content, altitude, vegetation coverage, and evaporation. Moreover, predictive models developed by multiple
regressions were relatively accurate when predicting DSLs, especially DSL–SWC. Understanding these associations with DSLs
formation in forestland is helpful for efficient water resource management, silviculture, and eco-environment restoration
on the Loess Plateau and in other water-limited regions around the world. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
