鄂尔多斯高原生态过渡带的判定及生物群区特征

THE DETERMINATION OF ECOTONE AND THE CHARACTERISTICS OF BIOME ON ORDOS PLATEAU

本文用Ｈｏｌｄｒｉｄｇｅ生命地带方法对鄂尔多斯高原的生物群区进行了分类研究，研制了用于生态过渡带判定的计算机模型，模拟结果与实际情况基本吻合。鄂尔多斯高原的生物群区可分为草原、荒漠灌丛和荒漠３大类，草原群区以本氏针茅（Ｓｔｉｐａｂｕｎｇｅａｎａ）群落为主，荒漠灌丛群区以冷蒿（Ａｒｔｅｍｉｓｉａｆｒｉｇｉｄａ），狭叶锦鸡儿（Ｃａｒａｇａｎａｓｔｅｎｏｐｈｙｌａ）群落为主，荒漠群区以红砂（Ｒｅａｕｍｕｒｉａｓｏｏｎｇｏｒｉｃａ）群落为主。鄂尔多斯高原的地带性植被在传统上分为典型草原、荒漠草原和草原化荒漠３部分，在典型草原的边界划分上，传统划分与本文结果一致。而在荒漠草原和草原化荒漠的边界方面，模拟结果与传统划分有一定的差异。荒漠灌丛和荒漠草原以及荒漠和草原化荒漠在生物群落特征上具有一定的相似性，荒漠灌丛和荒漠在生态特征上较荒漠草原和草原化荒漠更为旱化，在地理位置上更为靠西部。该计算机模型结合了地理空间分析，能准确地确定生态过渡带的位置和宽度，为研究鄂尔多斯高原生态过渡带的特征提供了较可靠的技术手段。

The biome of Ordos Plateau was classified by using the Holdridge system of life zone.A computer model developed to determine ecotone provides a technological basis for studying the character of ecotone on Ordos Plateau.The location and width of the ecotone can be determined by the computer model on Ordos plateau.The simulated results coincide with the natural status.The biome of Ordos Plateau can be divided into steppe with Form.Stipa bungeana,desert shrub with Form.Caragana stenophylla or Artemisia frigida and desert with Form.Reaumuria soongorica,corresponding with traditional vegetation classification of vegetation that can be divided into steppe,desertsteppe and steppedesert.The margin of steppe determined by traditional classification coincided with the results of the computer simulation,but the margin of desert shrub and desert biome determined by the computer simulation is different from the margin of desertsteppe and steppedesert vegetation.