Productive Overcompensation of Alpine Meadows in Response to Yak Grazing in the Eastern Qinghai-Tibet Plateau

Abstract

Understanding the interaction between large herbivores and pasture production, especially with respect to the grazing optimization hypothesis, is critical for pasture management and generating theoretical and testable predictions. However, the optimization hypothesis remains contradictory in alpine meadows on the Qinghai-Tibet Plateau (QTP). In this study, we tested the grazing optimization hypothesis using four yak-grazing intensities (no grazing, light grazing, moderate grazing and heavy grazing) in alpine meadow habitats from 2015 to 2017. The results indicated that species diversity did not differ significantly among grazing regimes during the experimental period. However, the aboveground net primary production (ANPP) under moderate grazing consistently significantly exceeded that in control enclosures over 3 years, confirming the grazing optimization hypothesis. Levels of overcompensation varied among grazing intensities and years, and grazing-induced plant compensation may only occur in the short term. The enhanced regrowth of Poaceae and Cyperaceae induced by yak grazing might contribute to the overall level of overcompensation by plant community. Our results strongly support the grazing optimization hypothesis in the context of alpine meadows grazed by yaks, emphasizing the complex interactions between ANPP, herbivores and other ecological factors in alpine meadows on the QTP. These findings provide new insights for the development of an ecological conservation strategy that will help restore this fragile ecosystem and balance the seemingly incompatible requirements of animal husbandry.

Contrasting effects of mammal grazing on foliar fungal diseases: patterns and potential mechanisms

“…Density‐dependent transmission of foliar fungal diseases (Zhu et al ., 2000; Mitchell et al ., 2002), especially rusts, may be a potential mechanism underlying the higher disease severity seen in grasses vs forbs, given the fact that several grasses (e.g. E. nutans and K. humilis ) were dominant species in our study site (Mipam et al ., 2019).…”

“…Our yak‐grazing experiment was located at the Qinghai‐Tibetan Plateau Research Base of Southwest Minzu University (32°48′N, 102°33′E; 3504 m above sea level (asl)), in Hongyuan County, Sichuan Province. In the study region, the mean annual temperature is 1.5°C, and the mean annual precipitation is 747 mm, 80% of which falls during the short, cold, growing season from May to September (Mipam et al ., 2019). The soils are classified as ‘Mat Cry‐gelic Cambisols’ according to the Chinese Soil Taxonomy (Gong, 1999).…”

“…A full description of our yak‐grazing experiment is provided in Mipam et al . (2019, 2021). Briefly, the experiment was established in a 10 ha flat meadow in late May 2015, with 12 large fenced plots (Mipam et al ., 2019).…”

“…light, moderate, and heavy grazing plots) was 1 ha, while that of control plots was 0.33 ha. The grazing treatment began in late May 2015; yaks grazed throughout the growing season, from late May to late September, every year (Mipam et al ., 2019).…”

Ideal temperature and storage period for commercial potato cultivars selected for frying

“…Low-temperature storage reduces losses from sprouting, wilting and diseases (XIAO et al, 2018). However, storage at temperatures lower than or equal to 6 ºC induce amylases and phosphorylases synthesis (MALONE et al, 2006) reducing starch content by reducing sugars (glucose and fructose) and causing sweetening cold induced (XIAO et al, 2018;HAMEED et al, 2018).…”