第 5 节 群落演替——相关论文石羊河上游旱泉沟流域垂直梯度上植物群落的演替格局（田丽慧，西北师范大学地理与环境科学学院，730070）摘要：石羊河上游旱泉沟流域是我国退耕还林项目的一个实验点，建于 2001 年。通过在该地取样，测植物的频度、盖度等，分析出优势种，进而推测该区域植物群落的演替格局。在垂直梯度上，经过封山育林，原生植物的根系发育，长出原生植被，再加上人工造林，该区域的植被类型由原来的单一趋于丰富。关键词：石羊河上游旱泉沟流域、垂直梯度、植物群落、演替格局 Abstract: Quangou dry upper reaches of the Shiyang River Basin is a project of returning farmland to forest experiment, built in 2001. And through the sampling, measurement of the frequency, coverage, analysis of the dominant species, plant communities in the region to speculate further the succession pattern. In the vertical gradient, after closing hillsides to facilitate afforestation, the original plant root development, the original vegetation grow, together with the artificial afforestation, the region's vegetation types from the original single into rich. Key words: Quangou dry upper reaches of the Shiyang River basin, the vertical gradient, plant communities, the pattern of succession Key words: Quangou dry upper reaches of the Shiyang River basin, the vertical gradient, plant communities, the pattern of succession旱泉沟流域是石羊河的上游源头区，也是古浪河的源头，其位于乌鞘岭的北麓。该地区地势较高，是青藏高原、黄土高原、内蒙古高原的交汇处，平均海拔大于 2000 米。该区降水稀少，年平均降水量在 400mm 以下，小区域气候变化明显，常有冰雹、干旱、霜冻和春季风雪等灾害发生。该区形成了典型的阴坡森林、阳坡草原的景观。天然林建群树种单一，结构简单。乔木林呈不连续的带状、块状分布，。常见的乔木有青海云杉、祁连圆柏群落的简单，分布不均，生长缓慢，天然更新不良，在高寒令量的气候下，涵养水源的功能下降。灌丛植被分布在坡度大、海拔高、积温低的区域，生长低矮，有机碳的积累少。阴坡的草原由于受大陆性荒漠气候...
