【作者】 卫智军；

【导师】 许志信；

【作者基本信息】 内蒙古农业大学 ， 草业科学， 2003， 博士

【摘要】 2000-2002年在短花针茅荒漠草原家庭牧场尺度上，从植物种群、群落、家畜牧食行为和生产性能以及经济效益方面对划区轮牧与自由放牧两种制度进行了比较研究，并提出了家庭牧场可持续经营的建议。主要研究成果如下： 1．划区轮牧与自由放牧相比，无芒隐子草和碱韭的地上生物量有增加的趋势。轮牧与禁牧区短花针茅地上生物量积累峰值一致，自由放牧区短花针茅地上生物量积累峰值滞后。 划区轮牧有利用短花针茅、无芒隐子草和碱韭株丛的分蘖，分蘖所产生的枝条生长良好；自由放牧抑制了适口性好的无芒隐子草和碱韭的分蘖，其分蘖产生的枝条数目显著少于轮牧和禁牧区。自由放牧条件下，短花针茅、无芒隐子草和碱韭的单枝重亦显著低于划区轮牧与禁牧处理。 2．划区轮牧有利于植物生殖枝的形成，单位面积上短花针茅的种子数较自由放牧高。放牧对植物有性繁殖产生不利影响，自由放牧对碱韭实生苗的存活产生的不利影响更为明显。 与自由放牧区相比，轮牧和禁牧区贮藏性碳水化合物生长季节含量较高，秋季积累与翌年早春含量也较高，植物的生长能力和早春返青生长能力均大于自由放牧。 3．自由放牧区在试验的第3年(2002年)出现了耐牧性较强的植物银灰旋花；冷蒿的密度、高度和盖度均呈增加趋势；强旱生植物兔唇花密度增加；一年生植物种群的密度和盖度较高，说明自由放牧区草地开始发生退化，草地环境也趋于旱化。 轮牧区短花针茅盖度较自由放牧和禁牧区有增加的趋势；轮牧区与对照区无芒隐子草的密度和盖度差异不大，两者均高于自由放牧区。 试验第3年(2002年)Shannon-Wiener、Simpson和Pielou群落多样性指数自由放牧偏高于轮牧区，但从3种指数的影响因子重要值分布上看，轮牧区主要集中在建群种和优势种上，说明轮牧草地及其环境较自由放牧更稳定。 4．划区轮牧和对照区牧草现存量差异不明显，但高于自由放牧区。轮牧和对照区群落现存量动态呈先增加，然后又下降的动态规律，自由放牧植物现存量几乎一直呈下降趋势。 与轮牧和对照区相比，自由放牧区牧草在生长初期粗蛋白质、粗灰分、磷含量均较高，粗纤维含量较低；生长后期粗蛋白质、粗灰分、磷的含量均较低，粗纤维含量增加。 两种放牧制度草群均表现等补偿性生长，但从植物补偿性生长趋势上看，轮牧更有利于植物补偿性生长优势的发挥。5．划区轮牧可以改变家畜对放牧地的空间选择行为，使采食范围缩小，采食站重叠，草地得到均匀利用。划区轮牧绵羊较自由放牧绵羊采食时间短，卧息、反刍和站立时间长。无论采食量还是所获得与消化的能量和蛋白质均高于自由放牧绵羊。 轮牧绵羊体重较自由放牧绵羊体重变化波动小，且一直保持较高水平。两放牧制度绵羊增重无显著差异，总掉膘量自由放牧绵羊高于轮牧绵羊。6．从财务分析的各项指标看，轮牧获得利润的水平和获得利润的能力均高于自由放牧，采取轮牧制度利用草地可以显著提高家庭牧场的经济效益。划区轮牧在维持草地生态稳定性和保护生态环境方面起到了积极的作用。划区轮牧得到广大牧民和社会备界的认可，并起到了试验示范作用。 家庭牧场的可持续经营应从草地利用制度的改革着手，发展高产人工草饲料基地，优化群落结构和家畜个体品质，加快畜群周转，使家庭牧场经营形成一个科技含量高，自我调节能力强的生态经济体系，在保证草地健康发展与生态安全的同时，获取更大的经济效益。更多还原

【Abstract】 A comparative study was conducted during 2000-2002 with two grazing systems of rotational grazing and free stocking on family ranches in Stipa breviflora desert steppe. Evaluations on the aspects of plant population, community, animal grazing behaviour, production output and economic efficiency were made on the two systems and sustainable management strategies were proposed. The main results were as follows:1. Compared with free stocking, rotational grazing allowed more above-ground biomass accumulations of Cleistogenes songoriea and Allium polyrhizum. Peak productions of Stipa breviflora above-ground biomass under the two grazing system were simila, while the peak time was lagged in free stocking system.Rotational grazing was favorable for tillering, and subsequently, tiller growth in S. breviflora, C. songoriea and A. polyrhizum. hi contrast, free stocking prevented the plants from producing tillers and subsequent tiller growth in C. songoriea and A. polyrhizum. Under free stocking system, the weights of individual tillers of S. breviflora, C. songoriea and A. polyrhizum were significantly lower than those under rotational grazing system and in closed pasture.2. More reproductive tillers of the S. breviflora, and subsequently more seeds per unit area, were formed in rotational grazing area. Grazing had negative influences on plant sexual reproduction. Free stocking had obvious negative influences on seedling survival of A. polyrhizum.Compared with free stocking area, carbohydrate storage were high during growing period, as well as during Autumn and early Spring times, in the rotational grazing area and in the closed area. Subsequently, vigorous early spring growth and growth potential were found in the late two areas.3. In the free stocking area, Convolvulus ammannii, a tough grazing resistant plant indicator, appeared in the third year of the experiment (Year 2002). Plant density, height and coverage of Artemisia frigida were increased. Density of Lagochilius ilicifolius, a high drought resistant plant, was increased, densities and coverages of annual plants were also increased in the free stocking area, which was considered an indication of grassland degeneration and inhabit dehydration.Coverage of S breviflora in the rotational grazing area increased in compared with the free stocking area and the closed area. No significant differences were found with C. songoriea in plant density and coverage in rotational grazing area and in closed area, though the two indexes were all low in the free stocking area.In the third year of the experiment (Year 2002), Shannon-Wiener index, Simpson index, and Pielou index were all found higher in the free stocking area than in the rotational grazing area. However, the distribution of importance values for the influential factors with these indexes was concentrated on several dominant andconstructive species, which indicated that rotational grazed grassland was more stable than the free stocked one.4. No significant yield differences of standing forages were found in the rotational grazing area and in the closed area, which were all superior to the free stocking area. The standing forage productions in the rotational grazing area and in the closed area showed Low-High-Low patterns, while a straight decline pattern was found in the free stocking area.Herbages in the free stocking area had high contents of crude protein, ash, phosphorus, and low content of crude fiber in the early growth stage, and low contents of crude protein, ash, phosphorus, and high content of crude fiber in the late growth stage, in compared with the rotational grazing and closing of grazing.Equal compensation growth was found in the two grazing system, although rotational grazing seemed more favorable for compensation growth potential5. Animal spatial selection behaviours were modified by rotational grazing, which reduced the grazing area, overlaid the grazing stations, and made more evenly uses of grasslands. Animals in the rotational system had a shorter更多还原