北极新奥尔松Austre Lovénbreen冰川退缩迹地不同演替阶段的植物组成与植被群落特征分析

为开展新奥尔松地区苔原植物生长和植被演替对冰川退缩响应的研究,在Austre Lovénbreen冰川(简称A冰川)前沿不同年代冰缘线附近布设了植被样方,调查了样方内植物组成与群落结构。结果表明:(1)A冰川1990年冰缘线代表植被演替的初始阶段,样方内仅出现先锋植物挪威虎耳草(Saxifraga oppositifolia);(2)1936年冰缘线代表冰川退缩长达75年后植被发育的情况,样方内植物种类和个体数明显增多,植被群落以木本植物极柳(Salix polaris)和草本植物黄葶苈(Draba bellii)为主,地衣以寒生肉疣衣(Ochrolechia frigida)和鸡皮衣(Pertusaria sp.)等壳状地衣为主;(3)随着冰川迹地形成时间更长,植被趋向成熟阶段发展,样方内极柳占绝对优势,地衣的物种多样性和盖度显著增加,出现雪黄岛衣(Flavocetraria nivalis)和刺岛衣(Cetraria aculeata)等叶状地衣。初步结果表明冰川退缩迹地上的物种更替明显,群落结构发生着显著变化。

CHARACTERISTICS of SPECIES COMPOSITION AND COMMUNITY STRUCTUREON THEAUSTRE LOVENBREEN GLACIER FORELAND,NY-ÅLESUND,SVALBARD

To enable ongoing research on the growth of tundra plants, vegetation succession, and response to glacier retreat, vegetation quadrats were established on the Austre Lovénbreen glacier foreland, in Ny-Ålesund, Svalbard. Species composition and community structure were investigated during the scientific expedition to the Chinese Arctic Yellow River Station in 2012. Only the pioneer plant, Saxifraga oppositifolia, was found in quadrat No. 6 at the location of the A glacier terminus in 1990, representing the early stage of vegetation succession. Overall, the vegetation was dominated by Salix polaris, Draba bellii, and crustose lichens such as Ochrolechia frigida and Pertusaria sp., and there were increasing numbers of individual plants in quadrat No. 7, reflecting the vegetation composition after 75 years of glacier retreat. Over time following glacier retreat, the composition of the vegetation changes and develops to a mature type. Salix polaris predominated in the mature quadrats, coupled with the occurrence of foliose lichens like Flavocetraria nivalis and Cetraria aculeata. In addition, lichen diversity and coverage increased. The present study indicates that species composition and community structure on the Austre Lovénbreen glacier foreland have changed over time following glacier retreat.