A topographic perspective on the distribution of degraded meadows and their changes on the Qinghai‐Tibet Plateau, West China

Abstract

Meadow degradation is a serious environmental and ecological problem on the Qinghai‐Tibet Plateau. A topographic perspective on the changes in the severity of meadow degradation can yield vital information on the effectiveness of rehabilitative measures and efforts. This study aims to reveal the topographic properties of degraded meadows in relation to those of the general terrain in the Qingzhen Township of southern Qinghai Province of China comparatively. After degraded meadows were mapped at 3 levels of severity from satellite images recorded in 1995, 2001, and 2015, the topographic features of degraded meadows, intact meadows, and the changes between them were explored in a geographic information system. It is found that degraded meadows increased by 528.07 ha (15.21%) during 1995–2001, but lost 1,495.67 ha (37.40%) during 2001–2015. The most and the least severely degraded meadows experienced a loss whereas moderately degraded meadows increased, with most changes taking place between adjoining levels of severity. Topographically, the changes in degradation severity bear a consistent relationship with elevation and slope gradient in that more severely degraded meadows are located at a lower elevation of a gentler slope. The changes from degraded to intact meadows take place at a lower elevation on a gentler slope, an outcome likely attributable to the rehabilitative efforts.

Dynamic changes of land use/cover and landscape pattern in a typical alpine river basin of theQinghai‐TibetPlateau, China

“…The grasslands and water bodies decreased by 70 km 2 (−0.05%) and 22 km 2 (−0.86%), respectively, while the forest increased by 123 km 2 (0.35%), which mainly distributed in the downstream of the Niyang and Lhasa River, and the YZR main stream from Lhasa to Shannan. This result can be corroborated by studies of the Qinghai‐Tibet Plateau on alpine grassland degradation in recent decades (X. Li et al, 2018; F. Peng et al, 2020).…”

“…In addition, the continuous distribution of the landscape index is of great significance to the environment of the biological community. X. Li et al (2018) researched on the landscape gradient changes on the Qinghai‐Tibet Plateau, and showed that the implementation of ecological restoration policies has a significant effect on the grassland in low‐altitude areas. W. Li et al (2020) investigated the evolution of alpine wetland on the Qinghai‐Tibet Plateau through the landscape ecological index in the past 25 years.…”

Effects of Soil Physico-Chemical Properties on Plant Species Composition and Diversity Along an Elevation Gradient Over Alpine Grassland on the Qinghai-Tibetan Plateau, China

“…Some researchers have investigated grassland degradation and restoration from the view point of plant community, including grass coverage (Zhang et al, 2014), grassland net primary production (Chen et al, 2014), and grassland yield (Cai et al, 2015). Some studies have investigated environmental issues, such as topographic parameters (Li et al, 2018) and soil condition (Harris, 2010), and a series of studies have analyzed the relationship between plant community and environmental parameters. Based on species dominance, some studies have investigated the effect of environmental factors on species diversity patterns among different plant community types (Jiang et al, 2016).…”

“…For instance, the relationships between the physico-chemical parameters of soil and plant species have been analyzed in terms of geological structure and lithology (Do Carmo and Jacobi 2016; Hanaka et al, 2019). Topography plays a crucial role in grassland degradation because it affects the distribution of moisture and energy (Li et al, 2018). The QTP has complex topographic features with contiguous mountains and hills.…”

“…Implications for alpine grassland managementAnalyzing the effects of soil physico-chemical properties on plant species composition and diversity within different plant communities along an elevation gradient provides guidance that could be used to improve the grassland management of different community types. The results can be used to improve grassland restoration programs and the construction of alpine grassland(Li et al, 2018). The different effects of soil variables on plant species composition and the diversity of different plant community types help explain species distribution patterns and the formation of communities.…”