Effects of short-term grazing prohibition on soil physical and chemical properties of meadows in Southwest China

Abstract

Background Grassland plays an important role in the ecosystem, but overgrazing harms the grassland system in many places. Grazing prohibition is an effective method to restore grassland ecosystems, and it plays a great role in realizing the sustainable development of grassland systems. Therefore, it is necessary to carry out research on the influence of regional grazing prohibition on the physical and chemical properties of different grassland systems. Methods In Potatso National Park, Southwest China, we selected experimental plots in the artificial grazing meadow area to study the effects of grazing prohibition on plant and soil indexes in subalpine meadows and swamp meadows. We investigated the biomass and species diversity of grazing prohibition treatment and grazing treatment plots and sampled and tested the soil index. The variation percentage was used to remove the original heterogeneity and yearly variation, allowing us to compare differences in plant index and soil index values between grazing prohibition and grazing treatments. Results Grazing prohibition increased the aboveground biomass, total biomass, total meadow coverage, average height, richness index, Shannon diversity index and evenness index and reduced the belowground biomass and root/shoot ratio in the subalpine meadow and swamp meadow. Additionally, grazing prohibition reduced the pH and soil bulk density and increased the soil total carbon, soil organic carbon, soil total nitrogen, soil hydrolyzable nitrogen, soil total phosphorus and soil available phosphorus in the subalpine meadow and swamp meadow. Nonmetric multidimensional scaling (NMDS) analysis showed that both plant indexes and soil indexes were significantly different between grazing and grazing prohibition treatments and between meadow types. Short-term grazing prohibition had a great impact on improving the fertility of meadow soil in the study area. We suggest that long-term and extensive research should be carried out to promote the restoration and sustainable development of regional grassland systems.

Responses of carbon dynamics to grazing exclusion in natural alpine grassland ecosystems on the QingZang Plateau

“…Different habitat conditions were the key factors that controlled the influences of GE on carbon storage between alpine meadow and alpine steppe, with more carbon could be accumulated in relatively humid regions (alpine meadow) than that in the relatively arid regions (alpine steppe) (Su and Xu, 2021;Sun et al, 2020b). Both in the alpine meadow and alpine steppe, GE was more effective in promoting AGB than BGB (Figure 2A), which is consistent with other studies (Xiong et al, 2014;Hong et al, 2015;Zhu et al, 2021). According to previous studies, plants would allocate more biomass to belowground parts to minimize the loss caused by grazing (Diaz et al, 2007;Yan et al, 2013).…”

“…Specifically, in terms of plant biomass, some studies observed that GE increased the aboveground biomass (AGB) (Liu and Nie, 2012;Yang et al, 2017) and the belowground biomass (BGB) (Du and Gao, 2021;Wang F, et al, 2020), while other studies found that GE could have a relatively neutral effect on AGB (Yuan et al, 2020) or negative impacts on AGB (Yan et al, 2014) and BGB (Wu et al, 2021). A previous study observed that short-term GE increased AGB but decreased BGB in the alpine meadow (Zhu et al, 2021). Other studies found that AGB increased and then decreased (Chen et al, 2019), BGB decreased and then increased (Hong et al, 2015) with the extension of GE duration across the alpine steppe.…”

Analyzing the Process of Land-Use Transfer Flow in the Suhai Lake Basin in China, 1980–2018

“…At the same time, the soil nitrogen cycle was also affected, and soil bulk density and soil organic matter content decreased, which reduced the plant density and species richness of the grassland. The long-term grazing ban will lead to the degradation of grassland vegetation and soil nutrients [40,41]. It follows that the optimal prohibition time may vary under different conditions [42].…”

Plant biotype interacting grazing activity shapes grassland ecosystem functions

“…In New Zealand, for example, substantial areas of alpine tall tussock grasslands have been restricted from grazing to reduce the negative impact on the ecosystem (Norton & Young, 2016). In northern China, the “grazing exclusion” policy has been implemented on severely degraded grasslands since the early 1990s to curb the degradation (Tai et al, 2021; Zhu et al, 2021). In southeastern Australia, best management practices have been implemented for decades to naturally recover deteriorated grasslands due to animal treading, which substantially improved physical properties of the soil, such as hydraulic conductivity, macropore volume, and bulk density (Drewry, 2006).…”