贵州人工草地植被盖度和地上生物量及碳氮含量对放牧的响应
|
摘要
过度放牧是贵州喀斯特人工草地退化主要人为驱动力之一。研究贵州喀斯特人工草地放牧管理策略,对贵州人工草地的可持续发展有重要指导意义。本研究结合无人机技术对草地植被盖度进行调查,比较不同放牧强度对植被盖度、地上生物量、植被地上部碳氮含量的影响和相同模拟放牧强度对不同混播草地植被盖度、生物量、植被地上部碳氮含量的影响,分析地上生物量、植被地上部碳氮含量与盖度的相关性。结果表明,轻度放牧下,植被盖度、地上生物量鲜重、地上生物量干重和植被地上部碳氮比分别比重度放牧显著升高了16.4%、302.4%、292.5%和132.1%(p<0.01),植被地上部氮含量显著降低了58.2%(p<0.01),放牧强度对植被地上部碳含量影响不显著(p>0.01);在相同模拟放牧强度干扰下,混播组合对植被盖度、地上生物量(鲜重和干重)、植被地上部碳、氮含量和碳氮比的影响均不显著(p>0.01)。相比于相同植被类型模式下的混播组合,草地盖度和地上生物量等的响应更受制于放牧强度调控,这进一步揭示,目前放牧强度下,贵州本地人工草地需要采取更低放牧强度的管理策略。不同放牧强度下,地上生物量、植被地上氮含量与植被盖度的相关性较好,结合无人机航拍图片,可为家庭牧场地上生物量和氮含量的无损、快速监测提供可行的途径。
Overgrazing is one of the most important human driving force to Guizhou karst artificial grassland degradation.The research on Guizhou karst artificial grassland grazing management strategyhas important guiding significance to the sustainable development of artificial pasture in Guizhou.Using unmanned aerial vehicle(UAV)technology to investigate vegetation coverage,this research compared the effects of the different grazing intensities on the vegetation coverage,aboveground biomass,aboveground carbon and nitrogen content,and also compared the effects of different mixed sowing combinations on the vegetation coverage,aboveground biomass,aboveground carbon and nitrogen content under the same simulated grazing intensity.The correlation of the aboveground vegetation,aboveground biomass,carbon and nitrogen content with vegetation coverage were also analyzed,respectively.The results showed that compared with heavy grazing,the vegetation coverage,aboveground biomass fresh weight,aboveground biomass dry weight and aboveground C∶N under light grazing significantly increased by 16.4%,302.4%,292.5% and 132.1%(p<0.01),respectively;the aboveground nitrogen content decreased significantly by 58.2%(p <0.01).The impacts of grazing intensities on aboveground carbon content were not significant(p >0.01).Under the same simulated grazing intensities,different mixed sowing combinations had no significant effect on aboveground biomass(fresh weight and dry weight),abovegr-ound carbon and nitrogen content and aboveground C ∶N(p>0.01).Compared with mixed seeding combinations,which vegetation type were same,response of vegetation coverage,aboveground biomass,etc.,were more limited by grazing intensity,which further suggested that lower grazing intensity management strategy in Guizhou local artificial grassland is needed.Under different grazing intensities,the aboveground biomass,aboveground nitrogen content had good correlation with vegetation coverage,which could provide a feasible way to monitor aboveground biomass and aboveground nitrogen content for family ranch combined with the UAV images.
Overgrazing is one of the most important human driving force to Guizhou karst artificial grassland degradation.The research on Guizhou karst artificial grassland grazing management strategyhas important guiding significance to the sustainable development of artificial pasture in Guizhou.Using unmanned aerial vehicle(UAV)technology to investigate vegetation coverage,this research compared the effects of the different grazing intensities on the vegetation coverage,aboveground biomass,aboveground carbon and nitrogen content,and also compared the effects of different mixed sowing combinations on the vegetation coverage,aboveground biomass,aboveground carbon and nitrogen content under the same simulated grazing intensity.The correlation of the aboveground vegetation,aboveground biomass,carbon and nitrogen content with vegetation coverage were also analyzed,respectively.The results showed that compared with heavy grazing,the vegetation coverage,aboveground biomass fresh weight,aboveground biomass dry weight and aboveground C∶N under light grazing significantly increased by 16.4%,302.4%,292.5% and 132.1%(p<0.01),respectively;the aboveground nitrogen content decreased significantly by 58.2%(p <0.01).The impacts of grazing intensities on aboveground carbon content were not significant(p >0.01).Under the same simulated grazing intensities,different mixed sowing combinations had no significant effect on aboveground biomass(fresh weight and dry weight),abovegr-ound carbon and nitrogen content and aboveground C ∶N(p>0.01).Compared with mixed seeding combinations,which vegetation type were same,response of vegetation coverage,aboveground biomass,etc.,were more limited by grazing intensity,which further suggested that lower grazing intensity management strategy in Guizhou local artificial grassland is needed.Under different grazing intensities,the aboveground biomass,aboveground nitrogen content had good correlation with vegetation coverage,which could provide a feasible way to monitor aboveground biomass and aboveground nitrogen content for family ranch combined with the UAV images.
引文
[1]JIANG Z,LIAN Y,QIN X.Rocky desertification in Southwest China:Impacts,causes,and restoration[J].Earth-Science Reviews,2014,132(3):2-10.
[2]HUANG Q H,CAI Y L.Assessment of karst rocky desertification using the radial basis function network model and GIS technique:a case study of Guizhou Province,China[J].Environmental Geology,2006,49(8):1173.
[3]XU E Q,ZHANG H Q.Characterization and interaction of driving factors in karst rocky desertification:a case study from Changshun,China[J].Solid Earth,2014,6(2):1329.
[4]任继周.放牧,草原生态系统存在的基本方式:兼论放牧的转型[J].自然资源学报,2012,27(8):1259-1275.REN J Z.Grazing,the Basic Form of Grassland Ecosystem and Its Transformation[J].Journal of Natural Resources 2012,27(8):1259-1275.
[5]莫本田,罗天琼,唐成斌,等.贵州南部混播草地几种建植因素最佳组合研究[J].中国草地学报,2000(3):29-33.MO B T,LUO T Q,TANGC B,et al.A Study on the Optimal combination of a few establishing factors on the mix sowing grassland in south Guizhou[J].Grassland of China,2000(3):29-33.
[6]孙红,于应文,马向丽,等.长期刈牧利用下贵州高原黑麦草+白三叶草地养分和植被构成变化[J].草业科学,2013,30(10):1575-1583.SUN H,YU Y W,MA X L,et al.Change of nutrients and botanical composition of mixed Lolium perenne+Trifolium repens grasslands under long-term grazing and mowing utilizations[J].Prataculture Science,2013,30(10):1575-1583.
[7]CASHMAN P A,MCEVOY M,GILLILAND T J,et al.A comparison between cutting and animal grazing for dry-matter yield,quality and tiller density of perennial ryegrass cultivars[J].Grass&Forage Science,2016,71(1):112-122.
[8]KACHAMBA D,覫RKA H,GOBAKKEN T,et al.Biomass Estimation Using 3D Data from Unmanned Aerial Vehicle Imagery in a Tropical Woodland[J].Remote Sensing,2016,8(11):968.
[9]YI S.FragMAP:a tool for long-term and cooperative monitoring and analysis of small-scale habitat fragmentation using an unmanned aerial vehicle[J].International Journal of Remote Sensing,2016:1-12.
[10]YI S,CHEN J,QIN Y,et al.The burying and grazing effects of plateau pika on alpine grassland are small:a pilot study in a semiarid basin on the Qinghai-Tibet Plateau[J].Biogeosciences,2016,13(22):6273-6284.
[11]CHEN J,YI S,QIN Y,et al.Improving estimates of fractional vegetation cover based on UAV in alpine grassland on the Qinghai-Tibetan Plateau[J].International Journal of Remote Sensing,2016,37(8):1922-1936.
[12]RUAN Xirui,DING Leilei,WANG Zhiwei,et al.Research on Vegetation Coverage Status of Urban-rural Fringe in Guizhou Using Unmanned Aerial Vehicle[J].Agricultural Science&Technology,2017,18(8):1367-1370.
[13]何峰,李向林,万里强,等.四川低山丘陵地区多年生冷季型优良牧草引种试验[J].中国草地学报,2006,28(6):106-109.HE Feng,LIXianglin,WAN Liqiang,et al.Introduction Experiment on Perennial Cool-Season Forages in Low Mountain Area of Sichuan Province[J].Chinese Journal of Grassland,2006,28(6):106-109.
[14]丁磊磊,王普昶,舒健虹,等.放牧强度与“草土畜”研究进展[J].黑龙江畜牧兽医,2017(4):93-97.DING L L,WANG P C,SHU J H,et al.Research progress on grazing intensity and"grass soil animals"[J].Heilongjiang Animal Science and Veterinary Mediciene,2017(4):93-97.
[15]TAMARTASH R,JALILVAND H,TATIAN M R.Effects of grazing on chemical soil properties and vegetation cover(case study:Kojour rangelands,Noushahr,Islamic Republic of Iran)[J].Pakistan Journal of Biological Sciences,2007,10(24):4391.
[16]HAN G D,HAO X Y,ZHAO M L,et al.Effect of grazing intensity on carbon and nitrogen in soil and vegetation in a meadow steppe in Inner Mongolia[J].Agriculture Ecosystems&Environment,2008,125(1-4):21-32.
[17]马少薇,郭建英,李锦荣,等.放牧强度对短花针茅群落特征及冠层截留的影响[J].中国草地学报,2016,38(5):66-70.MA Shaowei,GUOJianying,LI Jinrong,et al.Effect of grazing intensity on Stipa breviflora communities and canopy interception[J].Chinese Journal of Grassland,2016,38(5):66-70.
[18]SU R,CHENG J,CHEN D,et al.Effects of grazing on spatiotemporal variations in community structure and ecosystem function on the grasslands of Inner Mongolia,China.[J].Scientific Reports,2017,7(1):40.
[19]TAO Z,ZHANG Y,XU M,et al.Light-intensity grazing improves alpine meadow productivity and adaption to climate change on the Tibetan Plateau[J].Scientific Reports,2015,5(5):15949.
[20]高永恒.不同放牧强度下高山草甸生态系统碳氮分布格局和循环过程研究[D].成都:中国科学院成都生物研究所,2007.GAO Yongheng.Study on carbon and nitrogen distribution pattern and cycling process in an alpine meadow ecosystem under different grazing intensity[D].Chengdu:Chengdu Institute of Biology,Chinese Academy of Science,2007.
[21]WANG X Y,MCCONKEY B G,VANDENBYGAART A J,et al.Grazing improves C and N cycling in the Northern Great Plains:a meta-analysis[J].Scientific Reports,2016,6:33190.
[22]董晓玉,傅华,李旭东,等.放牧与围封对黄土高原典型草原植物生物量及其碳氮磷贮量的影响[J].草业学报,2010,19(2):175-182.DONG Xiaoyu,FU Hua,LI Xudong,et al.Effects on plant biomass and CNP contents of plants in grazed and fenced steppe grasslands of the Loess Plateau[J].Acta Prataculture Sinica,2010,19(2):175-182.
[23]徐沙,龚吉蕊,张梓榆,等.不同利用方式下草地优势植物的生态化学计量特征[J].草业学报,2014,23(6):45-53.XU Sha,GONG Jirui,ZHANG Ziyu,et al.The ecological stoichiometry of dominant species in different land uses type of grassland[J].Acta Prataculture Sinica,2014,23(6):45-53.
[24]丁小慧,宫立,王东波,等.放牧对呼伦贝尔草地植物和土壤生态化学计量学特征的影响[J].生态学报,2012,32(15):4722-4730.DINGX H,GONG L,WANG D B,et al.Grazing effects on eco-stoichiometry of plant and soil in Hulunbeir Inner Mogolia[J].Acta Ecologica Sinica,2012,32(15):4722-4730.
[25]李红琴,毛绍娟,祝景彬,等.放牧强度对高寒草甸群落碳氮磷化学计量特征的影响[J].草业科学,2017,3(3):449-455.LI H Q,MAO SJ,ZHU J B,et al.Effects of grazing intensity on the ecological stoichiometry characteristics of alpine meadow[J].Pratacultural Scicnce,2017,34(3):449-455.
[26]李香真,陈佐忠.不同放牧率对草原植物与土壤C,N,P含量的影响[J].草地学报,1998,6(2):90-98.LI Xianzhen,CHEN Zuozhong.Influences of stocking rates on C,N,P contents in plant-soil system[J].Acta Agrfsita Sinca,1998,6(2):90-98.
[27]杨惠敏,王振南,吉春荣.刈割和放牧后牧草碳氮动态研究进展[J].中国草地学报,2013,35(4):102-109.YANG Huimin,WANG Zhennan,JI Chunrong.Research progress in forages the dynamics of carbon and nitrogen after cutting and grazing[J].Chinese Journal of Grassland,2013,35(4):102-109.
[28]殷秀杰,燕昌江,崔国文,等.放牧对小叶章营养成分及其消化率的影响[J].中国草地学报,2013,35(2):94-98.YIN Xiujie,YAN Changjiang,CUI Guowen,et al.Influences of grazing on nutrition content,digestibility of Deyeuxia angustifolia[J].Chinese Journal of Grassland,2013,35(2):94-98.
[29]SALA O E,OESTERHELD M,LE譫N R J C,et al.Grazing effects upon plant community structure in subhumid grasslands of Argentina[J].Plant Ecology,1986,67(1):27-32.
[30]ZHENG S,LI W,LAN Z,et al.Functional trait responses to grazing are mediated by soil moisture and plant functional group identity[J].Scientific Reports,2015,5:18163.
[31]李香真,邢雪荣,陈佐忠.不同放牧率对旱黄梅衣生物量和化学元素组成的影响[J].应用生态学报,2001,12(3):369-373.LI Xiangzhen,XING Xuerong,CHEN Zuozhong.Effect of grazing rate on biomass and element composition of Xanthoparmelia camtschadalis[J].Chinese Journal of Applied Ecology,2001,12(3):369-373.
[32]VOURC′H G,MARTIN J L,DUNCAN P,et al.Defensive adaptations of Thuja plicata to ungulate browsing:a comparative study between mainland and island populations[J].Oecologia,2001,126(1):84-93.
[33]FRANK D A,EVANS R D.Effects of native grazers on N cycling in a north temperate grassland ecosystems[J].Ecology,1997,78:2238-2248.
[34]CHEN J,STARK J M.Plant species effects and carbon and nitrogen cycling in a sagebrush-crested wheatgrass soil[J].Soil Biology&Biochemistry,2000,32(1):47-57.
[35]秦洁,韩国栋,王忠武,等.内蒙古不同草地类型隐子草种群对放牧强度的响应[J].生态环境学报,2016,25(1):36-42.QIN Jie,HAN Guo dong,WANG Zhongwu,et al.Response of cleistogenes to grazing intensity in different grasslands of Inner Mongolia[J].Ecology and Environmental Sciences,2016,25(1):36-42.
[36]董全民,马玉寿,李青云,等.牦牛放牧强度对高寒草甸暖季草场植被的影响[J].草业科学,2004,21(2):48-53.DONG Quanmin,LIQingyun,MA Yushou,et al.Effects of yaks stocking pates on aboveground and belowground blomass in kobrecia parva alpine meadow[J].Prataculture Science,2004,21(2):48-53.
[37]LAMAS M I B,LARREGUY C,CARRERA A L,et al.Changes in plant cover and functional traits induced by grazing in the arid Patagonian Monte[J].Acta Oecologica,2013,51(8):66-73.
[38]BAO Yajing,LI Zhenghai,ZHONG Yankai.Compositional dynamics of plant functional groups and their effects on stability of community ANPPduring 17 yr of mowing succession on Leymus chinensis Steppe of Inner Mongolia,China[J].Journal of Integrative Plant Biology,2004(10):1155-1162.
[39]梁琴,陶建平,张炜银.植物功能型及其划分方法[J].西南大学学报(自然科学版),2007,29(10):97-103.LIANG Qin,TAO Jianping,ZH-ANG Weiyin.Plant functional types and its classification[J].Journal of Southwest University(Natural Science Edition),2007,29(10):97-103.
[40]BAOYIN T,LI F Y,MINGGAGUD H,et al.Mowing succession of species composition is determined by plant growth forms,not photosynthetic pathways in Leymus chinensis,grassland of Inner Mongolia[J].Landscape Ecology,2015,30(9):1795-1803.
[41]CARSTENSEN J,KRAUSE-JENSEN D,BALSBY T J S.Biomass-cover relationship for eelgrass meadows[J].Estuaries and Coasts,2016,39(2):440-450.
[42]RTTGERMANN M,STEINLEIN T,BEYSCHLAG W,et al.Linear relationships between aboveground biomass and plant cover in low open herbaceous vegetation[J].Journal of Vegetation Science,2000,11(1):145-148.
[2]HUANG Q H,CAI Y L.Assessment of karst rocky desertification using the radial basis function network model and GIS technique:a case study of Guizhou Province,China[J].Environmental Geology,2006,49(8):1173.
[3]XU E Q,ZHANG H Q.Characterization and interaction of driving factors in karst rocky desertification:a case study from Changshun,China[J].Solid Earth,2014,6(2):1329.
[4]任继周.放牧,草原生态系统存在的基本方式:兼论放牧的转型[J].自然资源学报,2012,27(8):1259-1275.REN J Z.Grazing,the Basic Form of Grassland Ecosystem and Its Transformation[J].Journal of Natural Resources 2012,27(8):1259-1275.
[5]莫本田,罗天琼,唐成斌,等.贵州南部混播草地几种建植因素最佳组合研究[J].中国草地学报,2000(3):29-33.MO B T,LUO T Q,TANGC B,et al.A Study on the Optimal combination of a few establishing factors on the mix sowing grassland in south Guizhou[J].Grassland of China,2000(3):29-33.
[6]孙红,于应文,马向丽,等.长期刈牧利用下贵州高原黑麦草+白三叶草地养分和植被构成变化[J].草业科学,2013,30(10):1575-1583.SUN H,YU Y W,MA X L,et al.Change of nutrients and botanical composition of mixed Lolium perenne+Trifolium repens grasslands under long-term grazing and mowing utilizations[J].Prataculture Science,2013,30(10):1575-1583.
[7]CASHMAN P A,MCEVOY M,GILLILAND T J,et al.A comparison between cutting and animal grazing for dry-matter yield,quality and tiller density of perennial ryegrass cultivars[J].Grass&Forage Science,2016,71(1):112-122.
[8]KACHAMBA D,覫RKA H,GOBAKKEN T,et al.Biomass Estimation Using 3D Data from Unmanned Aerial Vehicle Imagery in a Tropical Woodland[J].Remote Sensing,2016,8(11):968.
[9]YI S.FragMAP:a tool for long-term and cooperative monitoring and analysis of small-scale habitat fragmentation using an unmanned aerial vehicle[J].International Journal of Remote Sensing,2016:1-12.
[10]YI S,CHEN J,QIN Y,et al.The burying and grazing effects of plateau pika on alpine grassland are small:a pilot study in a semiarid basin on the Qinghai-Tibet Plateau[J].Biogeosciences,2016,13(22):6273-6284.
[11]CHEN J,YI S,QIN Y,et al.Improving estimates of fractional vegetation cover based on UAV in alpine grassland on the Qinghai-Tibetan Plateau[J].International Journal of Remote Sensing,2016,37(8):1922-1936.
[12]RUAN Xirui,DING Leilei,WANG Zhiwei,et al.Research on Vegetation Coverage Status of Urban-rural Fringe in Guizhou Using Unmanned Aerial Vehicle[J].Agricultural Science&Technology,2017,18(8):1367-1370.
[13]何峰,李向林,万里强,等.四川低山丘陵地区多年生冷季型优良牧草引种试验[J].中国草地学报,2006,28(6):106-109.HE Feng,LIXianglin,WAN Liqiang,et al.Introduction Experiment on Perennial Cool-Season Forages in Low Mountain Area of Sichuan Province[J].Chinese Journal of Grassland,2006,28(6):106-109.
[14]丁磊磊,王普昶,舒健虹,等.放牧强度与“草土畜”研究进展[J].黑龙江畜牧兽医,2017(4):93-97.DING L L,WANG P C,SHU J H,et al.Research progress on grazing intensity and"grass soil animals"[J].Heilongjiang Animal Science and Veterinary Mediciene,2017(4):93-97.
[15]TAMARTASH R,JALILVAND H,TATIAN M R.Effects of grazing on chemical soil properties and vegetation cover(case study:Kojour rangelands,Noushahr,Islamic Republic of Iran)[J].Pakistan Journal of Biological Sciences,2007,10(24):4391.
[16]HAN G D,HAO X Y,ZHAO M L,et al.Effect of grazing intensity on carbon and nitrogen in soil and vegetation in a meadow steppe in Inner Mongolia[J].Agriculture Ecosystems&Environment,2008,125(1-4):21-32.
[17]马少薇,郭建英,李锦荣,等.放牧强度对短花针茅群落特征及冠层截留的影响[J].中国草地学报,2016,38(5):66-70.MA Shaowei,GUOJianying,LI Jinrong,et al.Effect of grazing intensity on Stipa breviflora communities and canopy interception[J].Chinese Journal of Grassland,2016,38(5):66-70.
[18]SU R,CHENG J,CHEN D,et al.Effects of grazing on spatiotemporal variations in community structure and ecosystem function on the grasslands of Inner Mongolia,China.[J].Scientific Reports,2017,7(1):40.
[19]TAO Z,ZHANG Y,XU M,et al.Light-intensity grazing improves alpine meadow productivity and adaption to climate change on the Tibetan Plateau[J].Scientific Reports,2015,5(5):15949.
[20]高永恒.不同放牧强度下高山草甸生态系统碳氮分布格局和循环过程研究[D].成都:中国科学院成都生物研究所,2007.GAO Yongheng.Study on carbon and nitrogen distribution pattern and cycling process in an alpine meadow ecosystem under different grazing intensity[D].Chengdu:Chengdu Institute of Biology,Chinese Academy of Science,2007.
[21]WANG X Y,MCCONKEY B G,VANDENBYGAART A J,et al.Grazing improves C and N cycling in the Northern Great Plains:a meta-analysis[J].Scientific Reports,2016,6:33190.
[22]董晓玉,傅华,李旭东,等.放牧与围封对黄土高原典型草原植物生物量及其碳氮磷贮量的影响[J].草业学报,2010,19(2):175-182.DONG Xiaoyu,FU Hua,LI Xudong,et al.Effects on plant biomass and CNP contents of plants in grazed and fenced steppe grasslands of the Loess Plateau[J].Acta Prataculture Sinica,2010,19(2):175-182.
[23]徐沙,龚吉蕊,张梓榆,等.不同利用方式下草地优势植物的生态化学计量特征[J].草业学报,2014,23(6):45-53.XU Sha,GONG Jirui,ZHANG Ziyu,et al.The ecological stoichiometry of dominant species in different land uses type of grassland[J].Acta Prataculture Sinica,2014,23(6):45-53.
[24]丁小慧,宫立,王东波,等.放牧对呼伦贝尔草地植物和土壤生态化学计量学特征的影响[J].生态学报,2012,32(15):4722-4730.DINGX H,GONG L,WANG D B,et al.Grazing effects on eco-stoichiometry of plant and soil in Hulunbeir Inner Mogolia[J].Acta Ecologica Sinica,2012,32(15):4722-4730.
[25]李红琴,毛绍娟,祝景彬,等.放牧强度对高寒草甸群落碳氮磷化学计量特征的影响[J].草业科学,2017,3(3):449-455.LI H Q,MAO SJ,ZHU J B,et al.Effects of grazing intensity on the ecological stoichiometry characteristics of alpine meadow[J].Pratacultural Scicnce,2017,34(3):449-455.
[26]李香真,陈佐忠.不同放牧率对草原植物与土壤C,N,P含量的影响[J].草地学报,1998,6(2):90-98.LI Xianzhen,CHEN Zuozhong.Influences of stocking rates on C,N,P contents in plant-soil system[J].Acta Agrfsita Sinca,1998,6(2):90-98.
[27]杨惠敏,王振南,吉春荣.刈割和放牧后牧草碳氮动态研究进展[J].中国草地学报,2013,35(4):102-109.YANG Huimin,WANG Zhennan,JI Chunrong.Research progress in forages the dynamics of carbon and nitrogen after cutting and grazing[J].Chinese Journal of Grassland,2013,35(4):102-109.
[28]殷秀杰,燕昌江,崔国文,等.放牧对小叶章营养成分及其消化率的影响[J].中国草地学报,2013,35(2):94-98.YIN Xiujie,YAN Changjiang,CUI Guowen,et al.Influences of grazing on nutrition content,digestibility of Deyeuxia angustifolia[J].Chinese Journal of Grassland,2013,35(2):94-98.
[29]SALA O E,OESTERHELD M,LE譫N R J C,et al.Grazing effects upon plant community structure in subhumid grasslands of Argentina[J].Plant Ecology,1986,67(1):27-32.
[30]ZHENG S,LI W,LAN Z,et al.Functional trait responses to grazing are mediated by soil moisture and plant functional group identity[J].Scientific Reports,2015,5:18163.
[31]李香真,邢雪荣,陈佐忠.不同放牧率对旱黄梅衣生物量和化学元素组成的影响[J].应用生态学报,2001,12(3):369-373.LI Xiangzhen,XING Xuerong,CHEN Zuozhong.Effect of grazing rate on biomass and element composition of Xanthoparmelia camtschadalis[J].Chinese Journal of Applied Ecology,2001,12(3):369-373.
[32]VOURC′H G,MARTIN J L,DUNCAN P,et al.Defensive adaptations of Thuja plicata to ungulate browsing:a comparative study between mainland and island populations[J].Oecologia,2001,126(1):84-93.
[33]FRANK D A,EVANS R D.Effects of native grazers on N cycling in a north temperate grassland ecosystems[J].Ecology,1997,78:2238-2248.
[34]CHEN J,STARK J M.Plant species effects and carbon and nitrogen cycling in a sagebrush-crested wheatgrass soil[J].Soil Biology&Biochemistry,2000,32(1):47-57.
[35]秦洁,韩国栋,王忠武,等.内蒙古不同草地类型隐子草种群对放牧强度的响应[J].生态环境学报,2016,25(1):36-42.QIN Jie,HAN Guo dong,WANG Zhongwu,et al.Response of cleistogenes to grazing intensity in different grasslands of Inner Mongolia[J].Ecology and Environmental Sciences,2016,25(1):36-42.
[36]董全民,马玉寿,李青云,等.牦牛放牧强度对高寒草甸暖季草场植被的影响[J].草业科学,2004,21(2):48-53.DONG Quanmin,LIQingyun,MA Yushou,et al.Effects of yaks stocking pates on aboveground and belowground blomass in kobrecia parva alpine meadow[J].Prataculture Science,2004,21(2):48-53.
[37]LAMAS M I B,LARREGUY C,CARRERA A L,et al.Changes in plant cover and functional traits induced by grazing in the arid Patagonian Monte[J].Acta Oecologica,2013,51(8):66-73.
[38]BAO Yajing,LI Zhenghai,ZHONG Yankai.Compositional dynamics of plant functional groups and their effects on stability of community ANPPduring 17 yr of mowing succession on Leymus chinensis Steppe of Inner Mongolia,China[J].Journal of Integrative Plant Biology,2004(10):1155-1162.
[39]梁琴,陶建平,张炜银.植物功能型及其划分方法[J].西南大学学报(自然科学版),2007,29(10):97-103.LIANG Qin,TAO Jianping,ZH-ANG Weiyin.Plant functional types and its classification[J].Journal of Southwest University(Natural Science Edition),2007,29(10):97-103.
[40]BAOYIN T,LI F Y,MINGGAGUD H,et al.Mowing succession of species composition is determined by plant growth forms,not photosynthetic pathways in Leymus chinensis,grassland of Inner Mongolia[J].Landscape Ecology,2015,30(9):1795-1803.
[41]CARSTENSEN J,KRAUSE-JENSEN D,BALSBY T J S.Biomass-cover relationship for eelgrass meadows[J].Estuaries and Coasts,2016,39(2):440-450.
[42]RTTGERMANN M,STEINLEIN T,BEYSCHLAG W,et al.Linear relationships between aboveground biomass and plant cover in low open herbaceous vegetation[J].Journal of Vegetation Science,2000,11(1):145-148.