黄土丘陵区微地形条件下草本群落特征与土壤水分及养分关系分析

Relation Analysis of Herbaceous Community Characteristics and Soil Moisture and Nutrients on Micro-scale Topography Typical Section in Hilly Loess Plateau Region,China

以黄土丘陵区纸坊沟流域为研究区,通过对典型断面固定样地草本群落特征、土壤水分和养分的调查和测定,研究了微地形尺度典型断面草本群落特征与土壤水分、养分的关系。结果表明:群落地上生物量及物种多样性等生物学特征指标在不同坡向的大小顺序基本为:阴坡>阳坡和半阴半阳坡,在不同坡位的大小顺序基本为:坡下部>坡中、上部,这与土壤养分和土壤水分在阴坡含量较高并且在坡底富集的现象相关。相关分析表明:土壤各养分指标与群落生物学特征之间有关系,相比较而言土壤含水量与群落各生物学特征指标相关性更好,说明土壤水分是限制植物生长的关键限制性因子。

In order to study the relationship between the characteristics of herbaceous community and soil environment factors,this paper investigated and determined the relationship of the characteristics of herbaceous community and soil moisture and nutrients of typical cross-section in Zhifanggou watershed of Loess Hilly and Gully Region.The result showed that the aboveground biomass and species diversity index of community in shady slope were higher than that of those in sunny slope and half-sunny slope,and greater in lower slope position than that of those in upper slope and middle slope positions,which was correlated with the phenomenon of higher soil nutrient and moisture content in shady slope and enrichment at the lower slope.The correlation analysis showed that soil nutrients were correlated with the characteristics of herbaceous community,and soil moisture content was significantly positive correlated with Alatalo index and aboveground biomass（P〈0.01）.In comparison,soil moisture is the key factor of limiting plant growth.