Journal Article

The variation in soil water retention of alpine shrub meadow under different degrees of degradation on northeastern Qinghai-Tibetan plateau

Guo, Xiaowei, Cao, Guangmin, Du, Yangong, Ke, Xun, Dai, Licong, Zhang, Fawei

2021

Overview

Background and aims In recent decades, an increasing proportion of alpine shrub meadow has become severely degraded owing to the combined effects of global climate warming and rodent infestation, with significant impacts on soil water retention. The present paper investigates the patterns and controlling factors of soil water retention of alpine shrub meadow under different degrees of degradation, to help inform decisions on the management of degraded alpine shrub meadow. Methods Four degradation stages were defined: non-degradation (ND); light degradation (LD); moderate degradation (MD) and higher degradation (HD). Pearson correlation and redundancy analysis were used to examine the relationships between soil physical properties and soil hydraulic properties. Results Sand content increased while clay content decreased with increasing degree of degradation. In HD treatment, the available nitrogen and soil bulk density of surface soil layer was significantly lower than that in the other three stages, whereas the soil organic matter content and soil total porosity of surface soil layer was increased significantly, the soil compaction of 0–10 cm soil depth in HD was reduced significantly. The soil water retention of 0–60 cm soil depth first decreased and then increased with increasing degradation, with the maximum values occurring in HD, and the soil organic matter has an overwhelming effect on soil water retention than soil texture. Conclusions As the degree of degradation increased, the surface soil structure deteriorated, and available nitrogen reduced while soil organic matter increased sharply in higher degradation, which leads to the highest soil water retention in higher degradation. Our results suggested that the soil water retention in degraded alpine grassland was largely determined by soil organic matter, and the soil organic matter parameters should be incorporated in hydrological models of degraded alpine ecosystem.

• Publisher: Springer Science + Business Media,Springer International Publishing,Springer,Springer Nature B.V
• Subject: Alpine ecosystems / Alpine environments / alpine grasslands / Biomedical and Life Sciences / Bulk density / China / clay fraction / climate / Climate change / Climate effects / Comparative analysis / Correlation analysis / Degradation / Ecology / Ecosystem biology / ecosystems / Environment models / Environmental aspects / Global climate / Global warming / Grasslands / Hydraulic properties / Hydraulics / Hydrologic models / Hydrology / Laboratories / Life Sciences / Meadows / Moisture content / Nitrogen / Organic matter / Particle size / Photodegradation / Physical properties / Plant Physiology / Plant Sciences / Porosity / Properties / Protection and preservation / Redundancy / Regular Article / REGULAR ARTICLES / Retention / rodents / sand fraction / shrubs / Soil compaction / Soil degradation / Soil density / Soil depth / Soil investigations / Soil layers / Soil moisture / Soil organic matter / Soil physical properties / Soil porosity / Soil properties / Soil Science & Conservation / Soil structure / Soil surfaces / Soil texture / Soil water / soil water retention / Texture / Varieties / Water depth