Effects of Stocking Rate on the Variability of Peak Standing Crop in a Desert Steppe of Eurasia Grassland

Abstract

Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha(-1) month(-1); light (LG), 0.15 sheep ha(-1 )month(-1); moderate (MG), 0.30 sheep ha(-1) month(-1); and heavy (HG), 0.45 sheep ha(-1) month(-1)] on standing crop at the community level and partitioned by species and functional groups, in the desert steppe of Inner Mongolia, China. The treatments were arranged in a completely randomized block design over a 9-year period. Standing crop was measured every August from 2004 to 2012. Peak standing crop decreased (P < 0.05) with increasing stocking rate; peak standing crop in the HG treatment decreased 40 % compared to the control. May-July precipitation explained at least 76 % of the variation in peak standing crop. MG and HG treatments resulted in a decrease (P < 0.05) in shrubs, semi-shrubs, and perennials forbs, and an increase (P < 0.05) in perennial bunchgrasses compared to the control. The coefficients of variation at plant functional group and species level in the LG and MG treatments were lower (P < 0.05) than in the control and HG treatments. Peak standing crop variability of the control and HG community were greatest, which suggested that LG and MG have greater ecosystem stability.

Long‐term impacts of grazing intensity on soil carbon sequestration and selected soil properties in the arid Eastern Cape, South Africa

“…Reports indicated that reduced root growth in the presence of grazing pressure might affect the rooting biomass contribution to the soil organic matter pool . Reduced root allocation usually influences soil carbon inputs and also decreases nitrogen retention within the soil . Our results confirm previous reports of positive impacts of grazing exclusion on soil nutrients …”

“…Continuous grazing put an additional pressure on ecosystems of such fragile soils with low vegetation cover. On the other hand, exclosure as a method of land restoration is said to increase SOC sequestration through higher above‐ and below‐ground biomass and species richness …”

Grazing intensity and climate factors shape species abundance distribution by influencing different components of plant communities in a desert steppe

“…This creates opportunities for less preferable species, for example, S. breviflora to establish dominance in the plant community, resulting in reduced evenness. Grazing‐induced increase in species dominance has been extensively reported in previous studies (Calvert, ; Du et al, ; Hiernaux, ; Milchunas, Sala, & Lauenroth, ; Wang et al, ).…”

Grazing exclusion—An effective approach for naturally restoring degraded grasslands in Northern China

“…In general, the higher the stocking rate, the more negative the impact on soil properties. Stocking rates may have direct or indirect impacts on soil properties by influencing plant stands (Wang et al, ), soil and root respiration (Chen, Hou, Chen, Wan, & Millner, ), and animal behavior while grazing (Lin et al, ). An optimal stocking rate is difficult to define as it varies with various factors, such as grazing practices (Dong, Zhao, Wu, & Chang, ) and animal type. Geographical and climatic conditions have a fundamental effect on the soil biogeochemistry of grasslands in relation to grazing practices.…”

“…Grasslands, one of the largest terrestrial ecosystems in the world, are crucial for wildlife habitat (Galli et al, ), livestock forage (Odriozola, García‐Baquero, Laskurain, & Aldezabal, ), and the livelihoods of nearly 800 million people globally (FAOSTAT, ). In China, about 390 million ha of grasslands (Wang et al, ) cover 41% of the total land area (Anonymous, ). Of which, about 84% (or 330 million ha) is suitable for grazing, but a significant proportion has been degraded due to overgrazing (Wu, Zhao, Yu, Luo, & Pan, ), reclamation to croplands (Xu, Chen, Luo, & Lin, ), and exploitation of by‐products or mineral resources (Dong & Yang, ).…”