长白山岳桦苔原过渡带动态与气候变化

应用样带网格调查方法 ,对长白山岳桦苔原过渡带上岳桦径级结构、分布格局以及过渡带的环境因子进行调查 ,并与最近几十年的极端低温进行了对比研究 ,用格局的差异和径级结构的动态变化来揭示全球变暖对岳桦苔原过渡带的影响。结果表明 :全球气候变暖对长白山岳桦苔原过渡带产生很大影响 ,气候变暖使得岳桦苔原过渡带中的岳桦分布主要以幼苗和幼树为主 ,其中岳桦的径级分布呈倒J字型 ,过渡带中岳桦种群格局呈聚集型分布。整个岳桦种群随着全球气候变暖有一种整体向上迁移的趋势 ,尤其以岳桦苔原过渡带最为明显 ,岳桦苔原过渡带变宽 ,岳桦向苔原侵入的程度加剧。

THE EFFECT OF GLOBAL CLIMATE CHANGE ON THE DYNAMICS OF Betula ermanii-TUNDRA ECOTONE IN THE CHANGBAI MOUNTAINS

By using transect net-check, the class structure of Betula ermanii, the distribution pattern and environment factors are studied in the Betula ermanii-tundra ecotone in the Changbai Mountains, and compared with the lowest temperature in recent years. The effect of global climate change on Betula ermanii-tundra ecotone has been demonstrated by the difference of distribution and dynamics of structure. The results show that global climate change has greatly influenced on Betula ermanii-tundra ecotone; the seedling and young tree predominate in the Betula ermanii-tundra ecotone with global warming up; the class structure shows inverse J type; and the pattern exhibits mass distribution. The whole Betula ermanii population have a trend of moving up with the global warming up, which is most evident for the Betula ermanii-tundra ecotone. The Betula ermanii-tundra ecotone broaden with global warming up, and the degree of Betula ermanii invading tundra is more intensive.