Dynamic changes and distribution of topsoil moisture during the natural recovery of patchily degraded meadow towards healthy meadow on the Qinghai-Tibet Plateau of West China

IF 4.1 2区环境科学与生态学 Q1 ECOLOGY

Ecological Engineering Pub Date : 2025-08-25 DOI:10.1016/j.ecoleng.2025.107780

Zihan Song , Xilai Li , Yu Chai , Cazhaocairang , Jay Gao

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引用次数: 0

Abstract

Soil moisture is one of the limiting factors for the natural recovery of degraded patches towards healthy meadow. This study aims to understand the impact of interfering factors on soil moisture dynamics, and to determine the critical threshold for the area of degraded patches to exceed the lateral redistribution zone of soil moisture via a dual-factor randomized block design for plateau pika (Ochotona curzoniae) and overgrazing. The dynamic changes of soil moisture in three layers 10 cm, 20 cm and 30 cm below the surface were monitored near the interface between degraded patches and healthy alpine meadows, which was supplemented with the spatial dynamic changes of surface soil moisture tracked from time-series drone images. It is found that the moisture content of the 10 cm layer of healthy meadow was higher than that of the 20 cm and 30 cm layers thanks to the developed plant root system, and had a large range of fluctuation due to evaporation and transpiration. Due to the high variability of soil moisture decline rate, plateau pika and grazing had no significant effect on moisture (P > 0.05). One cause of variability was the much reduced absorption of soil moisture infiltration by degenerated patches, resulting in significant spatial heterogeneity in their absorption of rainwater (P < 0.05). This spatial heterogeneity results in the formation of lateral redistribution zones of soil moisture at the interface between alpine meadows and degraded patches. A high density of plateau pika significantly reduced the zonal width (P < 0.05). Recovered patches require supplemental moisture from the redistribution zone to maintain their water consumption. When the diameter of a degraded patch exceeds the limiting distance of the redistribution zone, the recovery of alpine meadow appears to be hysteretic, degenerating into patchily degraded meadow.

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土壤水分是退化斑块向健康草甸自然恢复的限制因素之一。本研究旨在通过高原鼠兔和过度放牧双因素随机区组设计，了解干扰因子对土壤水分动态的影响，确定退化斑块面积超过土壤水分横向再分布区的临界阈值。在退化斑块与健康高寒草甸交界面附近监测地表以下10 cm、20 cm和30 cm 3层土壤水分动态变化，并辅以无人机时序影像追踪的地表土壤水分空间动态变化。研究发现，由于植物根系发育，健康草甸10 cm含水率高于20 cm和30 cm含水率，且受蒸发和蒸腾作用影响波动幅度较大。高原鼠兔和放牧对土壤水分的影响不显著（P > 0.05）。变异的一个原因是退化斑块对土壤水分入渗的吸收大大减少，导致其对雨水的吸收具有显著的空间异质性（P < 0.05）。这种空间异质性导致了高寒草甸与退化斑块交界面土壤水分横向再分布带的形成。高原鼠兔的高密度显著降低了地带性宽度（P < 0.05）。恢复的斑块需要从再分配区补充水分来维持其水分消耗。当退化斑块的直径超过再分配带的极限距离时，高寒草甸的恢复表现出滞后性，退化为斑片状退化草甸。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Ecological Engineering 环境科学-工程：环境

CiteScore

8.00

自引率

5.30%

发文量

293

审稿时长

57 days

期刊介绍： Ecological engineering has been defined as the design of ecosystems for the mutual benefit of humans and nature. The journal is meant for ecologists who, because of their research interests or occupation, are involved in designing, monitoring, or restoring ecosystems, and can serve as a bridge between ecologists and engineers. Specific topics covered in the journal include: habitat reconstruction; ecotechnology; synthetic ecology; bioengineering; restoration ecology; ecology conservation; ecosystem rehabilitation; stream and river restoration; reclamation ecology; non-renewable resource conservation. Descriptions of specific applications of ecological engineering are acceptable only when situated within context of adding novelty to current research and emphasizing ecosystem restoration. We do not accept purely descriptive reports on ecosystem structures (such as vegetation surveys), purely physical assessment of materials that can be used for ecological restoration, small-model studies carried out in the laboratory or greenhouse with artificial (waste)water or crop studies, or case studies on conventional wastewater treatment and eutrophication that do not offer an ecosystem restoration approach within the paper.