In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents ...In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents and the correlation between the nutrient contents and altitudes.Four sampling sites were set up at altitudes of 2562,2660,2775 and 2905 m with the vertical distance among each sampling point was about 100 m.The results showed that the crude protein,ash and phosphorus contents of Elymus nutans decreased significantly with an increase in altitudes.The crude protein contents decreased by 1.87%with each 100 m increase in altitudes.The variation rule of crude protein contents with altitudes in the simulated curve was"y=-0.0187x+63.244(R^(2)=0.9557)".The crude ash contents decreased by 1.77%with each 100 m increase in altitudes.The variation rule of crude ash contents with altitudes in the simulated curve was"y=-0.0177x+56.144(R^(2)=0.978)".Neutral detergent fiber(NDF)and acid detergent fiber(ADF)showed an overall increasing trend with the increase of altitudes,but the most obvious increase was at 2775 m.The contents of crude fat and Ca did not change regularly with altitudes.展开更多
旨在通过不同放牧强度下高寒小嵩草（AlpineKobresia parva（Nees）Wang et Tang ex Y.C.Yang）草甸和垂穗披碱草（Elymus nutansGriseb.）/星星草（Puccinellia tenuiflora（Griseb.）Scribn.et Merr.）高寒混播草地暖季草场植物初级...旨在通过不同放牧强度下高寒小嵩草（AlpineKobresia parva（Nees）Wang et Tang ex Y.C.Yang）草甸和垂穗披碱草（Elymus nutansGriseb.）/星星草（Puccinellia tenuiflora（Griseb.）Scribn.et Merr.）高寒混播草地暖季草场植物初级生产力、土壤养分含量以及牦牛生产性能的研究,为草地合理利用提供有益的依据。结果表明：牦牛个体增重与放牧强度均呈线性关系;高寒小嵩草草甸暖季草场最适放牧强度为1.26头/hm2,垂穗披碱草/星星草混播高寒混播草地暖季草场的最适放牧强度是7.23头/hm2;放牧强度对高寒混播草地速效氮和速效磷的影响不显著,对速效钾的影响显著（P〈0.05）;随着放牧强度的提高,高寒小嵩草草甸土壤有机质、有机碳、全氮、全磷的含量呈减小趋势;当放牧强度分别达到1.07头/hm2,1.08头/hm2和1.22头/hm2时,0～5 cm,5～10 cm,10～20cm土壤速效氮含量依此达到最小;随着放牧强度的提高,高寒小嵩草草甸禾草和莎草的比例下降,可食杂草和毒杂草比例增加,而高寒混播草地垂穗披碱草的比例降低,星星...展开更多
基金Supported by the National Natural Fund(31872998)。
文摘In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents and the correlation between the nutrient contents and altitudes.Four sampling sites were set up at altitudes of 2562,2660,2775 and 2905 m with the vertical distance among each sampling point was about 100 m.The results showed that the crude protein,ash and phosphorus contents of Elymus nutans decreased significantly with an increase in altitudes.The crude protein contents decreased by 1.87%with each 100 m increase in altitudes.The variation rule of crude protein contents with altitudes in the simulated curve was"y=-0.0187x+63.244(R^(2)=0.9557)".The crude ash contents decreased by 1.77%with each 100 m increase in altitudes.The variation rule of crude ash contents with altitudes in the simulated curve was"y=-0.0177x+56.144(R^(2)=0.978)".Neutral detergent fiber(NDF)and acid detergent fiber(ADF)showed an overall increasing trend with the increase of altitudes,but the most obvious increase was at 2775 m.The contents of crude fat and Ca did not change regularly with altitudes.
