南宁市植物群落结构特征与局地小气候效应关系分析

Analysis on the relation between the structural characteristics of plant communities and the microclimate effects in Nanning City, China

关键词:  城市植被  群落结构  环境因子  生态效应  相关系数

Key words:  urban vegetation  community structure  environmental factor  ecological effects  correlation coefficients

摘要:

着重探讨植物群落结构特征与生态小气候因子间的相关性。结果表明:(1)在林荫处,植物群落总冠幅盖度、总密度、群落重要值均与温度成极显著的负相关; 植物群落群落重要值还与相对湿度达到显著正相关。(2)在林隙处,植物群落总平均株高与光照强度成显著正相关,与风速成极显著负相关。(3)植物群落结构特征与其小气候生态效应间的相关性是:总平均株高与遮光效应值达到极显著的正相关,与挡风效应值亦达到显著的正相关。另外,总冠幅盖度与降温效应值成极显著的正相关。同时,总密度与降温效应值亦成极显著的正相关。特别是群落重要值与降温、增湿、挡风、遮光等生态效应值都成显著甚至极显著的正相关。通过分析与探讨南宁市植物群落结构和小气候因子间的相关性机理,可为科学地进行城市绿化、生态城市建设提供理论依据。

Abstract:

The species,height,quantity,coverage,diameter at breast height of plants in 17 communities of 4 functional area in Nanning City were measured. The microclimate factors,such as atmosphere temperature(Ta),relative humidity(RH),light intensity(LI)and wind speed(WS)were also observed. The structural characteristics of plant communities and the correlation among the above indices were discussed in the light of ecological principles. The results show:(1)in the shade of the plant community,correlations between total coverage(TC),total density(TD)as well as community important value(CIV)are all very significantly negative correlated with atmosphere temperature(Ta)(were discussed in the light of ecological plinciples r=-0.883,-0.718 and -0.824,with P<0.01 respectively),while community important value(CIV)are significanthy positive correlated with relative humidity(RH)(r=0.594 with P<0.05);(2)in the hiatus,total mean height(TMH)and light intensity(LI)show singificant positive correlation(r=0.629 with P<0.05); it is signigicanthy negative correlation between total mean height(TMH)and wind speed(WS)(r=-0.725 with P<0.01). In addition,the plant communities'structures and their microclimate factors'effects show their correlations as follows:(1)it is significantly positive correlation between total mean height(TMH)and shade from light effect(SLE),as well as shelter from wind effect(SWE)(r=0.746 with P<0.01; r=0.653 with P<0.05 respectively);(2)total coverage(TC)and drop in atmosphere temperature effect(DATE)obviously correlate positive(r=0.896 with P<0.01),so do total density(TD)and drop in atmosphere temperature effect(DATE)for their correlation(r=0.742 with P<0.01);(3)community important value(CIV)and all effects of green areas'microclimate factors have significantly positive correlation,some of them even come to quite obviously positive level(r=0.833 with P<0.01; r=0.587 with P<0.05; r=0.675 with P<0.01; r=0.755 with P<0.01 respectively).