模拟牦牛和藏羊践踏对垂穗披碱草凋落物损失率和化学计量特征的影响  

Effect of short-term simulated yak and Tibetan sheep trampling on litters loss rate and decomposition characteristics of Elymus nutans

作　　者：周洋洋 张建文[1] 潘涛涛[1] 徐长林[1] 鱼小军[1] ZHOU Yang-yang;ZHAMG Jian-wen;PAN Tao-tao;XU Chang-lin;YU Xiao-jun(Sino-U.S.Centers for Grazingland Ecosystem Sustainability, Pratacultural Engineering Laboratory of Gansu Province,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院/草业生态系统教育部重点实验室/甘肃省草业工程实验室/中-美草地畜牧业可持续发展研究中心

出　　处：《草原与草坪》2019年第3期1-8,共8页Grassland and Turf

基　　金：国家自然科学基金(31760695)资助

摘　　要：为深入了解自然降雨条件下牦牛和藏羊践踏强度对青藏高原高寒草甸凋落物分解的分异影响,在天祝高寒草甸进行模拟牦牛和藏羊践踏调控试验,采用凋落物网袋法研究了牦牛和藏羊践踏强度对垂穗披碱草(Elymus nutans)凋落物损失率和化学计量特征(N、P、K和C含量)的影响。结果表明:存放1、2、3、13、14和15个月的凋落物损失率在各践踏处理下均呈增加趋势。同等牦牛和藏羊强度下,已存放1~15个月的垂穗披碱草凋落物损失率,凋落物N,P和K含量在牦牛践踏处理下均大于藏羊处理。垂穗披碱草凋落物损失率,N和P含量在藏羊轻度践踏处理下显著低于重度践踏,C和K含量在藏羊轻度践踏处理显著高于重度践踏(P<0.05)。且在2015年度已存放1,2和3个月与在2016年度已存放13,14和15个月的凋落物C和K含量均表现为释放模式,而凋落物N和P表现为富集模式。综合分析,牦牛和藏羊的践踏促进了凋落物的分解,牦牛践踏下垂穗披碱草凋落物的分解快于藏羊处理。In order to understand the differentiation effect of the yak and Tibetan sheep trampling intensity on the litter decomposition of alpine meadow on the Qinghai-Tibetan Plateau,the simulation experiment (simulated yak and Tibetan sheep trampling) was carried out in the alpine meadow in Tianzhu by using the litter bag method to measure the litter loss rate and stoichiometry (N,P,K and C contents) of Elymus nutans .The results showed that the loss rate of litter processed for 1,2,3,13,14 and 15 months under all trampling treatments showed an increasing trend.Under the same trampling strength,the litter loss rate of Elymus nutans stored for 1~15 months caused by yak was higher than Tibetan sheep.And the contents of litter N,P and K showed a same trend.The of litter loss rate,contents of N and P under Tibetan sheep light trampling treatment were significantly lower than that of heavy trampling treatment.The contents of C and K in Tibetan sheep light trampling treatment were significantly higher than that of heavy trampling treatment ( P <0.05).In addition,C and K of litter stored for 1,2 and 3 months in 2015 and 13,14 and 15 months in 2016 showed a release mode,while N and P of litter showed enrichment mode.It could be concluded that the livestock trampling promoted the litter decomposition,and the decomposition of the litter under the yak trampling was faster than that of Tibetan sheep.

关 键 词：模拟践踏 牦牛 藏羊 垂穗披碱草 凋落物 损失率 化学计量 

分 类 号：S543[农业科学—作物学]