荒漠草原植物多样性恢复与土壤生境的关系

Abstract

为揭示荒漠草原围栏封育后植物多样性的恢复对土壤生境的响应机制，以围栏封育和适度放牧草地的灰钙土和风沙土生境植物群落为研究对象，采用方差分析和冗余分析（redundancy analysis RDA）方法，研究了围栏封育后植物多样性的变化及其与土壤生境物理和化学因子的关系。结果表明：（1）相对于适度放牧利用，围栏封育显著降低了灰钙土和风沙土生境植物多样性；随着封育年限的增加，植物多样性呈现显著，且封育的负效应随着封育年限的增加而增加；（2）两种土壤生境下植物多样性与生物量均表现为负相关。植物群落对灰钙土和风沙土两种土壤生境下表现出的不同点有：（1）灰钙土生境下，植物多样性与砂粒正相关，生物量与有机碳，全氮正相关；（2）风沙土生境下，植物多样性与有机碳，全氮正相关，生物量与电导率正相关。未来荒漠草原退化草地植物多样性恢复需要充分考虑不同土壤生境类型的影响，草地管理需要采取适度利用和封育保护相结合道路。;In order to reveal the response mechanism of plant diversity restoration to soil habitat after fencing in desert steppe, the plant communities in sierozem soil and aeolian sandy soil habitats of fenced and moderately grazed grassland were selected as the research objects. The variance analysis and redundancy analysis (RDA)were used to study the changes of plant diversity after enclosure and its relationship with physical and chemical factors of soil habitat. The results showed that:(1) compared with moderate grazing, enclosure significantly reduced plant diversity in sierozem soil and aeolian sandy soil. With the increase of enclosure years, plant diversity was significant, and the negative effect of enclosure increased with the increase of enclosure years. (2) There was a negative correlation between plant diversity and biomass in both soil habitats. The differences of plant communities between sierozem soil and aeolian sandy soil were as follows:(1) In sierozem soil, plant diversity was positively correlated with sand, while biomass was positively correlated with organic carbon and total nitrogen. (2) In aeolian sandy soil, plant diversity was positively correlated with organic carbon and total nitrogen, as well as biomass was positively correlated with electrical conductivity. In conclusion, the effects of different soil habitat types should be fully considered in the restoration of plant diversity of the degraded grassland in desert steppe in the future.