我国干旱沙漠地区人工植被与环境演变过程中植物多样性的研究

PLANT DIVERSITY IN THE PROCESS OF SUCCESSION OF ARTIFICIAL VEGETA- TION TYPES AND ENVIRONMENT IN AN ARID DESERT REGION OF CHINA

以我国干旱沙漠区流沙治理的成功模式包兰铁路沙坡头地段人工植被防护体系作为研究对象 ,研究了区域人工植被与环境演变过程中植物多样性的变化特点。研究表明 :该区人工植被经过 40余年的演变其植物种的组成趋于动态平衡 ;植物多样性在时间尺度上的变化表现为随群落演替的进行而增大 ,42年前 (195 6年 )建立的人工植被多样性指数达到 D=0 .70 6～ 0 .82 2或 H′=1.393～ 1.893,10年前 (1987年 )建立的人工植被其多样性仅为 D=0 .5 0 1～ 0 .70 2或 H′=0 .819～ 1.0 74;β多样性的测度表明 ,沙坡头地区人工植被在其演变的历程中经历了 2次物种周转速率相对较快的阶段 ,这一特点与植被演替密切相关 ,对干旱沙漠地区的生态恢复和人工绿洲建设与管理具有重要的参考价值。本文还进一步研究了土壤基质条件等变化对植物多样性的影响。

The artificial vegetation protection system of the Shapotou section of the Baotou Lanzhou railway is a successful model for desert control in arid desert region in China.This paper addresses biodiversity in the process of the establishment and succession of artificial vegetation in this system.The species composition of artificial vegetation was observed to reach homeostasis after 40 years of succession,and plant diversity increased with community succession.The diversity index of the artificial vegetation reached D =0 706~0 822 or H′ =1 393~1 893 after 40 years of establishment,while the diversity index was only D =0 501~0 702 or H′ =0 819~1 074 at 10 years from establishment. β diversity patterns indicate that artificial vegetation of Shapotou region has come through two periods of relatively high species turnover rates,which were closely correlated with natural patterns of vegetation succession.These processes play an important role in the recovery of ecological condition in this arid desert region as well as in the establishment of artificial oasis vegetation.Data on the influence of improved soil condition on plant diversity is also presented.