Fu Gang, Wang Junhao, Li Shaowei
Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2022 Nov 1;845:157552. doi: 10.1016/j.scitotenv.2022.157552. Epub 2022 Jul 21.
The impacts of climate change and human activities on forage nutritional quality will affect nutrient capacity, livestock development and wildlife conservation in alpine regions. However, the response of forage nutritional quality to climate change and human activities remains indistinguishable across the whole Tibet. Here, six forage variables (i.e., crude protein, CP; ether extract, EE; crude ash, Ash; acid detergent fiber, ADF; neutral detergent fiber, NDF; water-soluble carbohydrates, WSC) together represented forage nutritional quality. We estimated potential forage CP, EE, Ash, ADF, NDF and WSC contents using growing mean air temperature, total precipitation and total radiation based on random forest models. We also estimated actual forage CP, EE, Ash, ADF, NDF and WSC contents using growing mean air temperature, total precipitation and total radiation, and maximum normalized difference vegetation index based on random forest models. Climate change had nonlinear effects on potential forage CP, EE, Ash, ADF, NDF and WSC contents. Radiation change predominated the variations of potential forage nutritional quality. Human activities altered the sensitivities of forage nutritional quality to climate change. The effects of human activities on forage nutritional quality increased with increasing longitude and precipitation, and decreasing elevation and radiation. Consequently, we should pay attention to the radiation change besides climate warming and precipitation change, at least for forage nutritional quality in alpine grasslands. The effects of human activities on forage nutritional quality can vary with longitude, elevation, precipitation and radiation in alpine grasslands.
气候变化和人类活动对牧草营养品质的影响将关乎高寒地区的养分容量、牲畜发展和野生动物保护。然而，在整个西藏地区，牧草营养品质对气候变化和人类活动的响应仍难以区分。在此，六个牧草变量（即粗蛋白，CP；乙醚提取物，EE；粗灰分，Ash；酸性洗涤纤维，ADF；中性洗涤纤维，NDF；水溶性碳水化合物，WSC）共同代表牧草营养品质。我们基于随机森林模型，利用生长季平均气温、总降水量和总辐射量估算了潜在的牧草CP、EE、Ash、ADF、NDF和WSC含量。我们还基于随机森林模型，利用生长季平均气温、总降水量、总辐射量以及最大归一化植被指数估算了实际的牧草CP、EE、Ash、ADF、NDF和WSC含量。气候变化对潜在的牧草CP、EE、Ash、ADF、NDF和WSC含量具有非线性影响。辐射变化主导了潜在牧草营养品质的变化。人类活动改变了牧草营养品质对气候变化的敏感性。人类活动对牧草营养品质的影响随着经度增加、降水量增加以及海拔和辐射量降低而增大。因此，除了气候变暖和降水变化外，我们还应关注辐射变化，至少对于高寒草原的牧草营养品质而言。在高寒草原，人类活动对牧草营养品质的影响会因经度、海拔、降水量和辐射量的不同而有所差异。
