【作者】 张静；

【导师】 侯琳；

【作者基本信息】 西北农林科技大学 ， 生态学， 2021， 硕士

【摘要】 祁连圆柏(Juniperus przewalskii)群落是青海省主要森林群落之一,在维持青藏高原生态安全、保育生物多样性和涵养水源等方面发挥着重要作用。因其分布海拔较高,交通不便,有关青海省祁连圆柏群落植物物种多样性特征鲜见报道。为了解祁连圆柏群落植物物种多样性特征及其影响因子,以青海省祁连圆柏群落为研究对象,通过野外调查与室内分析,探讨了该群落物种组成、区系特征、垂直分布格局和影响物种多样性的主导因子,以期为资源植物开发、柏树生态系统服务功能评估提供数据支撑。主要研究结果如下:(1)祁连圆柏群落内共有植物127种,隶属33科87属。其中资源(观赏、饲用和药用)植物117种。(2)祁连圆柏群落内物种丰富度随经度增大逐渐降低,灌木丰富度低于草本,物种丰富度在2900-3100m范围达到峰值。草本的物种丰富度沿海拔呈现双峰格局,2700m附近的峰值高于3600m。(3)灌木的α多样性指数,除Pielou指数沿海拔梯度逐渐降低外,其他多样性指数均呈现单峰格局:Shannon-Wiener指数与Simpson指数在海拔3100m左右达到峰值。草本的α多样性指数中Shannon-Wiener,Simpson与Pielou指数沿海拔梯度呈波动变化趋势。β多样性指数中的Whittaker指数与Cody指数在海拔2600-3000m范围达到最高值;Sorenson指数与Bray-Curtis指数除在海拔2400m附近处的变化较大外,其余海拔范围内变化趋势基本一致,均在海拔2600m附近处达到最大值。(4)植物区系地理成分,以世界广布、北温带和旧世界温带分布区类型为主。(5)祁连圆柏林地土壤含水量随深度增加下降,且生境差异对土壤养分含量影响差异较大。土壤理化性质对灌木、草本物种多样性影响不同。温带气候适宜祁连圆柏群落内植物生存;2900-3100m区域更适宜灌木生存,海拔2700m附近区域适于草本生长。海拔2300-2600m海拔段内物种更替速度较慢,海拔2600-3000m区域内更替速度加快,海拔升至3000m以上时,群落内物种的更替速度趋于稳定;祁连圆柏群落内资源植物种类丰富,可人工培养扩大种群数量,提高当地居民收入。更多还原

【Abstract】 As one of the main forest communities in Qinghai Province,the Juniperus przewalskii community plays an important role in maintaining the ecological security,conserving biodiversity and conserving water resources of the Qinghai-Tibet Plateau.Due to its high altitude and inconvenient transportation,there are few studies on the plant species diversity.In order to understand the plant species diversity and its influencing factors of J.przewalskii community in Qinghai province,this study selected the J.przewalskii community as the research object.Based on field investigation and lab analysis,the species composition,faunal characteristics,vertical distribution pattern and dominant factors affecting species diversity of J.przewalskii community in Qinghai province were discussed,in order to provide data support for resource plants exploitation and ecological benefit evaluation of J.przewalskii community.The results were as follows:(1)There were 127 species belonging to 33 families and 87 genera in the community of J.przewalskii in Qinghai province.There were 117 species of resource plants,which can be divided into three types according to their uses: medicinal plants,forage plants and ornamental plants.(2)Species richness of J.przewalskii community decreased gradually along the longitude gradient.The species richness of shrub layer was lower than herb layer and reached the highest at the altitude of 2900 m～3100m.The species richness of herb layer showed double peak curve,and the peak value near the altitude of 2700m was higher than that 3600m.(3)Besides Pielou index,the α diversity index of shrub layer showed single peak curve:Shannon-Wiener index and Simpson index reached the highest at the altitude of 3100m.In the α diversity index of herb layer,Shannon-Wiener index,Simpson index and Pielou index showed wave curve.Among β-diversity index,Whittaker index and Cody index reached the highest values in the range of 2600-3000m above altitude.Sorenson index and Bray-Curtis index had obvious different variation trends at the altitude of 2400m,but had similar variation trends in the rest of the altitude,and reached the maximum value at the altitude of 2600m.(4)The floristic areal types of the plants are mainly Widespread,North Temperate and Old World Temperate.(5)Soil water content of J.przewalskii community decreased with increasing depth,and the influence of habitat difference on soil nutrient content was great.Soil physical and chemical properties had different effects on the diversity of shrub and herb species.The temperate climate was more suitable for the survival of plants in the community of J.przewalskii in Qinghai province.The area of 2900-3100m was more suitable for shrub survival,and the area near the altitude of 2700m was more suitable for herb growth.The species replacement rate of J.community at the altitude of 2300-2600m was slow,and increased at the altitude of 2600-3000m,and to be stable when the altitude rised above 3000m.The resource plant species was rich,which can be cultivated artificially to enlarge the population,in order to enhance the income of local residents.更多还原