鄂尔多斯高原植物群落多样性时空变化特点

Temporal and spatial changes of plant community diversity on the Ordos Plateau

作者利用1999年和2000年野外植物群落调查资料,结合李博(1990)的植物群落调查结果,分析了鄂尔多斯高原植物群落多样性的时空变化特点。鄂尔多斯高原主要植物群落类型有23类,不同植被类型的群落多样性表现出一定的差异性,其中丰富度指数的差异不显著,而Simpson指数和Shannon-Wiener指数及群落盖度的差异明显。中东部典型草原表现为高多样性高盖度;西鄂尔多斯荒漠草原和草原化荒漠物种多样性较高,但盖度较低;毛乌素沙地植物群落物种多样性低,但盖度较高。从1986年到2000年,该地区典型草原群落、荒漠草原和沙地植被的群落多样性指数都有下降趋势;典型草原和草原化荒漠的群落盖度有所增加,荒漠草原有所下降。以上结果表明,沙地植被和草原化荒漠生物多样性已经得到了一定的保护,但还有待加强,而荒漠草原的保护亟待引起重视。

In order to provide a scientific basis for biodiversity protection on the Ordos Plateau, we compared plant community diversity in 1999 and 2000 with that in 1986 （Li, 1990）. The results indicated that the 23 major types of plant communities showed significant differences in Simpson index, Shannon-Wiener index, and coverage, but similar richness. Higher diversity and higher coverage occurred in the typical steppe in the middle-eastern sector of the plateau, while higher diversity but lower coverage was found in the desert-steppe and steppe-desert in the west, and lower diversity but higher coverage was found in the communities of the Maowusu sandland. From 1986 to 2000, the biodiversity and coverage of the communities had changed obviously. The biodiversity of typical steppe, desert-steppe and sandland vegetation showed a decreasing trend, whereas coverage of typical steppe and steppe-desert increased, and the coverage of the desert-steppe de- creased. We recommend that great attention should be paid to the ecological conservation of the desert-steppe as well as to species diversity of sandland vegetation and steppe desert.