黄土高原丘陵沟壑区山羊牧道景观对植物群落和土壤水分的影响

发布时间：2018-09-11 12:31

【摘要】：干旱、半干旱丘陵草原上分布着牲畜踩踏形成的网络状小路径和植被斑块组成的景观,称为牧道景观。这种牧道景观广泛分布于黄土高原丘陵沟壑区,其中以山羊牧道景观居多。本研究选取成熟山羊牧道半阴坡区域、禁牧后山羊牧道半阴坡区域、成熟山羊牧道阳坡区域和禁牧后山羊牧道阳坡区域四类区域,对比分析不同区域内植物群落特征、物种多样性特征、功能群特征与表层土壤含水量特征,并利用地统计分析方法和GS+9.1软件分析以上指标的空间分布,探讨山羊牧道景观对植物群落和土壤水分影响。同时分析山羊牧道景观结构单元尺度上,土壤水分空间分布规律,探讨山羊牧道可能引起的生态水文效应。通过分析得到以下结论：(1)牧道对植物群落组成和优势种有显著影响,成熟山羊牧道、禁牧后山羊牧道半阴坡均为多年生草本植物冷蒿(Artemisia frigida)和蓍状亚菊(Ajania achilloides)占绝对优势地位,灌木、半灌木、小半灌木次之,一、二年生草本植物最弱;而禁牧后山羊牧道阳坡草本植物占优势,其次为灌木、半灌木、小半灌木。牧道可以显著提高植被的覆盖度、地上生物量,对提高植物群落的物种多样性有一定影响。(2)成熟山羊牧道半阴坡区域、禁牧后山羊牧道半阴坡区域、成熟山羊牧道阳坡区域和无山羊牧道区域四类区域植被,在不同的尺度上均有较强的空间异质性。(3)山羊牧道景观结构不同位置具有不同的土壤水分分布和变化规律。山羊牧道下方凸起的植物聚集区30 cm及以下土层较山羊牧道和山羊牧道上方的陡坡位置具有较高的土壤含水量。成熟山羊牧道半阴坡区域、禁牧后山羊牧道半阴坡区域、成熟山羊牧道阳坡区域和无山羊牧道区域四类区域表层土壤含水量具有较强的空间异质性。表明牧道景观对降水有二次分配的作用。(4)山羊是形成山羊牧道景观的主要驱动力,山羊转移和采食行为可以影响牧道的结构的发育。
[Abstract]:In arid and semi-arid hilly grassland, the landscape consisting of small network paths and vegetation patches formed by livestock trampling is called pastoral landscape. This pastoral landscape is widely distributed in the hilly and gully areas of the Loess Plateau, in which the goat pastoral landscape is the most common. The characteristics of plant community, species diversity, functional groups and surface soil water content in different regions were compared and analyzed. The spatial distribution of the above indexes was analyzed by using the methods of geostatistical analysis and GS+9.1 software. At the same time, the spatial distribution of soil water on the scale of goat pasture landscape unit was analyzed, and the possible ecological and hydrological effects caused by goat pasture were discussed. After grazing, Artemisia FRIGIDA and Ajania achilloides were the dominant perennial herbs, followed by shrubs, semi-shrubs, small and semi-shrubs, and the weakest one or two-year-old herbs. After forbidding grazing, the dominant herbs were shrubs, semi-shrubs and small and semi-shrubs. Vegetation coverage and aboveground biomass can be significantly increased, and the species diversity of plant community can be improved. (2) Vegetation in the semi-shady slope area of mature goat pasture, semi-shady slope area of post-grazing goat pasture, sunny slope area of mature goat pasture and area without goat pasture has a strong space on different scales. (3) The distribution and variation of soil moisture were different in different locations of goat pasture landscape structure. The soil moisture content of 30 cm and below was higher than that of the steep slope above goat pasture and goat pasture. The spatial heterogeneity of soil water content in the surface layer of four regions, namely, the sunny slope area of mature goat pasture and the area without goat pasture, indicates that the pasture landscape plays a secondary role in precipitation distribution. (4) Goats are the main driving force for the formation of goat pasture landscape, and goat transfer and feeding behavior can affect the structure of pasture. Development.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P901

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