农牧交错带不同封育时间对植物特征值及多样性的影响

为研究我国北方农牧交错带不同封育时间对干旱、半干旱草原植物特征值及多样性的影响,同时探索农牧交错带草原封育周期,本研究选取位于我国农牧交错带的宁夏盐池人工封育草原为研究对象,采用样方调查法,于每年7-8月份(植物生长季节)对封育区植被生长状况进行调查,调查内容包括:植物名称、植物种数、株数、盖度、高度、地上生物量(鲜重)等。运用生态学、地统计学原理,结合Biodiversity Pro、Microcal Origin等生态学统计软件对外业数据进行处理、分析,结果表明:封育2-3年后植物群落优势种优势地位得到巩固,而一些伴生种则在竞争中消失;封育区植物特征值在封育2-3年后达到最大,如地上生物量(鲜重)在封育3年达到最大值,为6907.75kg/hm2,此后呈下降趋势;封育区主要植物重要值及植物物种多样性均在封育2-3年后出现最大值,此后也不同程度地呈下降趋势。

The Effect on the Plant Characteristic Values and Species Diversity of Different Fencing Time in the Farming- Pastoral Ecotones in the North of China

In order to study the effect of different fencing time to arid and semi-arid grassland' plant characteristic values and diversity,as well as to find out the optimum fencing period in the ecotone of Agriculture-animal Husbandry in the north of China,quadrat method was quoted to investigate plant growth during the growing season(Jun.,and Aug.) in the fencing tame grassland,in Yanchi County,Ningxia Hui Autonomous Region.The items investigated were,plant species,individual number,coverage,height,aerial biomass(fresh weight).Coped with ecological geo-statistic principles,data were processed and analyzed by the ecological statistic software like Biodiversity Pro,Microcal Origin etc.The results showed that after two to tree years' fencing,dominant plant community reinforced their dominant position with some companion species dying out in the competition.Plant characteristic values peaked during this time and descended later.(For instance,the aerial biomass reached the maximum,6907.75kg/ha,in the third year after the fencing.) In addition,both plant species diversity and the main plants' importance value showed the same trend.