【作者】 王小亮；

【导师】 韩国栋； 赵萌莉；

【作者基本信息】 内蒙古农业大学 ， 生态学， 2009， 硕士

【摘要】 草地放牧生态系统中,草、畜间的相互关系是放牧生态学的研究重点。试验于2007年～2008年在内蒙古四子王旗短花针茅草原进行,试验设3个载畜率水平和一个不放牧区作为对照,分别为轻度放牧(LG)、中度放牧(MG)、重度放牧(HG)和对照样地(CK),共4个处理,随机排列,各3次重复。本试验通过对荒漠草原不同载畜率下绵羊食谱构成、食性差异和食性功能群研究,探讨了荒漠草原不同载畜率下绵羊采食规律、采食状态和食性与草原群落间的关系,以及载畜率对绵羊食性及草地状况的影响,揭示不同载畜率下放牧绵羊食性规律和食物资源胁迫下食物替代规律。结果表明:(1) 2007～2008年食谱构成与植被组成的相似性指数变化趋势相反,MG区7月份相似性指数均较LG、HG区小。(2) 2007～2008年的7～10月,LG、MG、HG区,冷蒿、短花针茅、阿氏旋花均被绵羊采食。无芒隐子草、短花针茅、冷蒿、阿氏旋花、猪毛菜、栉叶蒿等六种植物总采食比重:LG区在94%以上,MG区97%以上,HG区达98%以上。(3) 2007、2008年,每个月份不同植物种间采食比重差异显著(P<0.05),各个月份不同处理间灌木类采食差异显著(P<0.05), 2008年多年生禾草、一二年生植物采食差异显著(P<0.05)。2007、2008年,同一处理不同月份的不同食性功能群采食差异显著(P<0.05)。(4)绵羊对各种牧草的喜食程度相对变化,2007、2008年, LG区7、8月无芒隐子草的嗜食性指数较大,表现为7月喜食、8月嗜食;HG区9月表现为嗜食。HG区8月短花针茅、栉叶蒿嗜食性指数较大表现为喜食。(5)同一年度不同载畜率下和月份间绵羊的各食性功能群相互补充、此消彼长,2007年禾草嗜食性指数比较低,LG区7、9月表现为喜食, MG、HG区各月份均表现为可食或少食;灌木类嗜食性指数LG区7、8、9月均表现为喜食或嗜食,而MG区7,8月表现为喜食,HG只有8月份表现为喜食;多年生杂类草各处理均表现为喜食或嗜食;HG区9月一、二年生植物表现为喜食、嗜食。(6) 2007年LG、MG、HG区食物多样性与植物多样性的相关性显著(P<0.05); 2008年LG、MG区显著(P<0.05),HG区不显著。年度变化上,MG区相关性升高,LG、HG区相关性均下降,HG区下降尤为明显。更多还原

【Abstract】 The relationship between grassland and animals is research emphasis of grazing ecology in ecosystem. The experiments was conducted on stipa breviflora desert steppe in Siziwang banner of Inner Mongolia from 2007 to 2008. Different stocking rate were setting up, that is light grazing (LG), moderate grazing (MG), heavy grazing (HG) and control (CK), and 4 treatments were offered with random order while each repeated 3 times. Through sheep diet composition, differences of feeding habits and diet function group at different stocking rates on desert steppe, the relationship among feed law, food intake state, feeding habits and grassland community were discussed. The daily diet composition and its seasonal changes of grazing sheep and the affects of different stocking rates on sheep diet and grassland condition was analyzed, The diet rules of grazing sheep at different stocking rates, and food replace regular under stress of food resources were revealed.The results were showed as follows:(1) The trend of similarity index of the composition of diet and vegetation composition was almost opposite during 2007 and 2008, Similarity indices of MG plot was lower compared with LG, HG in July.(2) Artemisia frigida, Stipa breviflora, and Convolvulus ammannii were daily forage of seasonal grazing sheep at LG, MG, HG plot in July from October during 2007 and 2008. Cleistogenes songorica, Stipa breviflora, Artemisia frigida, Convolvulus ammannii, Potentilla acaulis, and Neopallasia pectinata took a larger proportion of total feed intake. It was more than 94% in LG plot, more than 97% in MG plot, and more than 98% in HG plot during 2007 and 2008.The plant kind numbers of sheep intake in LG district was more than MG and HG. .(3) The difference of foraging proportion among different plant species in the same month was abvious(P<0.05). The difference of bush foraging was significant among different treatments in every month(P<0.05). The differences of foraging on grasses, annial plant, and biennial plant were abvious in 2008 (P <0.05). The differences of foraging on functional group of various feeding habit were distinct at the same treatment in different month (P <0.05).(4)The preference level of different forages changed relatively. During 2007 and 2008, acceptabilty index of Cleistogenes songorica was higher in HG plot in July and August. The species was favorite in July, preferable in August, and preferable in September in HG plot Stipa breviflora and Neopallasia pectinata were favorite in HG plot in August.(5) The functional groups of various feeding habit complemented each other at different stocking rates among months in the same year, preferable food index of grasses was lower in 2007, In LG plot, it expressed favorite in July and Sptember, In MG, HG plot , it was available or little. Preferable food index of shrubs presents favorite or preferable among July, August, and September in LG plot. While it presents favorite in July and August in MG plot. It noly presents favorite in August in LG plot. Preferable food index of perennial weeds presents favorite or preferable at various treatments. Preferable food index of annial and biennial plants present favorite or preferable in September in HG plot.(6) It had a great closely correlation between plant diversity and forage diversity among LG plot, MG plot and HG plot in 2007 (P<0.05). There was significant difference between plant diversity and food diversity in LG plot and MG plot (P<0.05), but no significant difference in MG plot in 2008. Plant diversity and food diversity were higher under the moderate grazing stress, the relative index of plant diversity and food diversity were decreased under light and heavy grazing rate , it was more abvious in HG plot. Foraging was single all the more.更多还原