【作者】 占布拉；

【导师】 卫智军；

【作者基本信息】 内蒙古农业大学 ， 草业科学， 2010， 博士

【摘要】 论文以科尔沁沙地草原为对象,在家庭牧场尺度上,于2005～2007年期间,用科尔沁牛进行划区轮牧和自由放牧两种放牧制度的比较研究,通过对固定、半固定和流动三种沙地类型植物种群、群落、土壤以及家畜牧食行为等项的野外观测、取样和室内实验、统计、分析,获得的研究结果如下:1.科尔沁沙地分为固定、半固定和流动三种沙地类型,不同类型沙地植物群落和特征不同。轮牧与自由放牧两种放牧制度对灌木层种群盖度、高度和密度的影响不显著;轮牧提高流动沙地群落及沙蓬的高度、盖度、密度;在半固定沙地轮牧与自由放牧两种放牧制度对白草的高度、盖度和密度影响不显著,轮牧提高达乌里胡枝子密度和盖度,对高度无影响。2.在科尔沁草地不同类型沙地和各个月份不同放牧处理条件下,轮牧有利于维持或提高植物群落的α多样性指数,同时轮牧条件与对照条件下群落的相似性指数最高。3.灌木层的主要植物种群中,差巴嘎蒿的重要值在三种不同处理条件下均排在首位。在流动沙地的植物群落中,沙蓬、虫实和狗尾草的重要值排前三位;半固定沙地的主要草本种群中,虫实、狗尾草、白草和达乌里胡枝子在三种不同处理条件下,其重要值排序都比较靠前;固定沙地的主要草本种群中,在对照条件下糙隐子草占绝对优势,达乌里胡枝子和白草次之;自由放牧条件下白草排在优势地位,但随时间推移达乌里胡枝子的地位逐渐上升,到了9、10月份糙隐子草排在优势地位;轮牧条件则是对照和自由放牧的一个中间过渡型。4.轮牧提高流动沙地和固定沙地植物群落的地上现存量,特别是提高灌木层小叶锦鸡儿,流动沙地沙蓬,固定沙地糙隐子草、达乌里胡枝子及芦苇的地上现存量;在半固定沙地,轮牧提高多年生植物和一年生植物地上现存量。灌木层植物种群与还原糖含量之间不存在线性关系,草本层的糙隐子草与还原糖含量之间存在显著的线性关系。5.木层种群实生苗数量轮牧>自由放牧>对照,差巴嘎蒿实生苗最多,榆树和东北木蓼的最少;草本层种群的实生苗数量对照>轮牧>自由放牧,达乌里胡枝子实生苗最多,糙隐子草的最少。不同植物的实生苗在生长季出现的时间不同,灌木种群的实生苗主要在7～9月份出现,草本植物的实生苗主要出现在6～7月份。6.科尔沁沙地土壤养分含量总体水平不高,不同类型沙地的土壤养分变化规律因养分种类的不同而不同。固定沙地的土壤全氮、全钾含量较半固定沙地高,半固定沙地土壤全氮、全钾含量较流动沙地土壤全氮、全钾含量高。固定沙地的土壤碱解氮含量较半固定沙地高,半固定沙地土壤碱解氮含量较流动沙地土壤碱解氮含量低。全氮和全磷,全氮和速效磷以及全磷和速效磷之间存在显著的相关性。固定沙地的土壤水分、有机质含量较半固定沙地高,半固定沙地土壤水分、有机质含量较流动沙地土壤水分、有机质含量高。7.科尔沁牛的采食选择性很强,不仅表现在牧草的种类上,还表现在牧草的生长季节上,主要选择那些易消化的植物种类或部位,在两种放牧制度的食谱中狗尾草所占的比例均高于45%。植物种群采食后的平均留茬高度在不同放牧制度的不同月份具有不同的表现,轮牧条件下表现为10月份>7月份>8月份>9月份;自由放牧条件下表现为10月份>9月份>8月份>7月份。科尔沁牛主要在半固定沙地上采食和活动。不同放牧制度下的采食速率、采食习性、排泄行为不同,轮牧条件下采食时间和采食路线短,采食速率和采食量高,反刍﹑卧息和站立时间均较长,排粪次数少。更多还原

【Abstract】 Effects of rotational and continuous grazing on plant population, community, soil characteristics and grazing behavior of Horqin cattle among fixed sandy land, semi-fixed sand land and shifting sandy land were comprehensively investigated by field observation, sampling, laboratory experiment and statistical analysis during 2005-2007. The main results were as follows:1. Horqin sand was divided into 3 types of sand, fixed sandy land, semi-fixed sandy land and shifting sandy land, different types of sand had different plant community and characteristics. There weren’t significant differences on shrub height, coverage and density between two grazing systems. Rotational grazing system enhanced height, coverage and density of community and Agriophyllum squarrosum in shifting sandy land. There weren’t significant differences in height, coverage, density of Pennisetum centrasiaticum between two grazing systems in semi-fixed sandy land. Rotational grazing system enhanced coverage, density of Lespedeza davurica. There weren’t significant differences in height of Lespedeza davurica between two grazing systems, however the rotational grazing system improved the density and coverage of while had no effect on height.2. Rotational grazing system was beneficial to maintain or improve plantαdiversity index in different months of treatment with different grazing conditions in Horqin sand, while the highest similarity index of community appeared in rotational grazing and control conditions.3. The important value of Artemisia halodendron in three different treatments was ranked in the first place in the shrub layer of the main plant populations, which of Agriophyllum squarrosum, Corispermum macrocarpum and Setaria viridis were higher in shifting sand land. And of Corispermum macrocarpum, Setaria viridis, Pennisetum centrasiaticum and Lespedeza davurica were all at front in different treatment. Cleistogenes squarrosa had absolute predominance in control condition, followed by Lespedeza davurica and Pennisetum centrasiaticum in herbaceous population of fixed sandy land, Pennisetum centrasiaticum had a dominance status but that of Lespedeza davuricaincreased gradually over time while Cleistogenes squarrosa in Sep. and Oct. appeared Outstanding. Rotational grazing conditions were an intermediate transitional between control and continuous grazing.4. Rotational grazing system enhanced the standing crops of plant community in shifting sand land and fixed sand land, especially enhanced the standing crops of Caragana microphyll, Agriophyllum squarrosum in shifting sand land, that of Cleistogenes squarrosa, Lespedeza davurica, Phragmites australis in fixed sand land. Rotational grazing system enhanced the standing crops of annual and perennial plants in semi-fixed sand land. There has no linear relationship between bush layer plant population and reducing sugar where there had a remarkable linear relationship between the herb layer plant populations and reducing sugar content.5. The number of plant seedlings in shrub layer was rotational grazing > continuous grazing > control plot, which in herb layer was control plot > rotational grazing > continuous grazing, the number of Artemisia halodendron in shrub layer and Lespedeza davurica in herb layer were largest but Ulmus pumila and Carex duriuscula and Cleistogenes squarrosa had a contrary result. Seedlings of different species appear at different time in the growing season. Shrub species seedlings mainly appeared from July to September, while herbaceous plants mainly in the June to July.6. Soil nutrient content of Horqin sand was not high, which also changed with different types of landscape patches. The contents of total nitrogen and potassium in fixed sand land were higher than that in semi-fixed sand, and of which in semi-fixed sandy soil were higher than that in drifting sand land. The contents of alkali nitrogen and in fixed sand were higher than that in semi-fixed sand, and of which in semi-fixed sand were lower than that in drifting sand land. The contents of total nitrogen and phosphorus, total nitrogen and available phosphorus and total phosphorus and available phosphorus were significantly correlative. Soil moisture and organic matter content in fixed sand was higher than that in semi-fixed sand, and of which in semi-fixed sand was higher than that in drifting sand land.7. The selective intake of Horqin cattle was high .Not only reflected in the types of forage, but also in grass growing season, which mainly selected the part that easy to digest, the proportion of Setaria viridis was higher than 45% both in two grazing systems. The average plant population stubble height had different performance in different months between different grazing systems, the performance under rotational grazing conditions was October >July >August >September; while in continuous grazing conditions showed October >September >August >July. Horqin cattle has mainly intake and activity in the semi-fixed sand. There had different feeding rate feeding habits and eliminative behavior in different grazing systems, the feeding line and feeding time is short in rotational grazing condition which had a high feed rate and feed intake, longer rumination, resting and standing time, less defecation times.更多还原