Impacts of Anthropogenic Activities and Climate Change on Forage Nutrition Storage in Tibetan Grasslands

Abstract

Uncertainties about the impacts of anthropogenic activities and climate change on forage nutrition storage of grasslands can limit the adaptive management of grasslands across the whole Tibetan Plateau. The main objective was to investigate the impacts of anthropogenic activities and climate change on the forage nutrition storage of grasslands on the Tibetan Plateau. Based on random forest models, we quantified the responses of forage nutrition storage to anthropogenic activities and climate change across the whole Tibetan grasslands from 2000 to 2020. Warming and increased precipitation did not always increase forage nutrition storage, and cooling and decreased precipitation did not always reduce forage nutrition storage. Compared to temperature and precipitation changes, radiation change had stronger contributions to potential and actual forage nutrition storage. Humankind's activities altered the impacts of climate change on forage nutrition storage. The impacts of anthropogenic activities on forage nutrition storage increased linearly with increasing mean annual temperature and decreasing elevation but showed quadratic relationships with longitude, mean annual precipitation and radiation. The change in the impacts of humankind’s activities on forage nutrition storage was more closely related to radiation change than temperature and precipitation changes. The findings observed by this study caution that the impacts of radiation change on forage nutrition forage should be taken seriously under global change. Both climate change and humankind activities cannot always increase forage nutrition storage but may cause the degradation of forage nutrition storage.

Effects of Climate Change and Fencing on Forage Nutrition Quality of Alpine Grasslands in the Northern Tibet

“…Forage nutrition quality of grasslands, as an important aspect of grassland evaluation, not only affects the growth and development of livestock, but also affects the yield and quality of livestock products [ 1 , 2 ]. Moreover, forage nutrition quality of grasslands can play a key role in the young recruitment and population dynamics of wild herbivores [ 3 , 4 ].…”

“…These findings imply that the general tendency of the response of forage nutrition quality to climate change and fencing in native grasslands remains unclear. Second, many studies have investigated the relationships between forage nutrition quality and aboveground biomass (AGB) in grasslands [ 1 , 27 ]. They found that forage nutrition quality is negatively correlated with AGB to some extent in grasslands [ 1 , 27 ].…”

“…Second, many studies have investigated the relationships between forage nutrition quality and aboveground biomass (AGB) in grasslands [ 1 , 27 ]. They found that forage nutrition quality is negatively correlated with AGB to some extent in grasslands [ 1 , 27 ]. However, few studies have examined the relationships between forage nutrition quality and plant species α-diversity and community composition at the landscape level in natural grasslands.…”

“…These diverse alpine grassland ecosystems are important components of global alpine ecosystems [ 20 , 30 ]. Alpine grasslands in the Northern Tibet have suffered and will continue to suffer from both climate change and human activities [ 1 , 13 ]. On one hand, the Northern Tibet, as one sensitive region to climate change, has been becoming and will continue to become warmer and wetter [ 13 ].…”

“…The main objectives of this study were to examine (1) whether there were trade-offs between forage nutrition quality and AGB and plant species richness, (2) whether climate change always decreased forage nutrition quality and fencing altered the sensitivity of forage nutrition quality to climate change, and (3) whether forage nutrition quality was more responsive to fencing in wetter and warmer regions in alpine grasslands across the Northern Tibet. Based on previous studies [ 1 , 27 ], we hypothesized that forage nutrition quality had trade-offs with AGB and plant species α-diversity. Based on other previous studies [ 2 , 8 ], we hypothesized that forage nutrition quality was more sensitive to fencing in wetter regions but not correlated with temperature.…”