摘要
通过对岷江干旱河谷植被及其环境因子的系统取样调查 ,研究了该地区植物群落的α多样性及其与环境因子的关系。土壤、植被、地形三者之间的典范相关分析结果表明 ,三者两两之间均存在着较高的相关性。土壤因子与地形因子之间 ,海拔和坡向起较大的作用 ,主要影响土壤中的全氮、有机质和土壤含水量 ;地形因子和植被之间 ,海拔和坡向影响灌木层的多样性和盖度 ;植被和土壤因子之间 ,土壤中的全氮量、有机质和土壤含水量影响灌木层的盖度和多样性。随着海拔的增加 ,草本和灌木群落的多样性都呈现出先增加后减小而后又增加的趋势 ,草本层的α多样性明显高于灌木层的α多样性 ,草本层和灌木层均在14 0 0～ 16 0 0 m和 2 0 0 0～ 2 2 0 0 m两个海拔段有较高的α多样性 ;华帚菊 -小黄素馨灌丛、金花小檗 -忍冬灌丛、绣线菊灌丛有着较高的多样性 ,西南野丁香灌丛、莸灌丛、小马鞍羊蹄甲 -白刺花灌丛的群落多样性较低 ;样带的多样性 ,灌木层 :样带 3>样带 1>样带 2 ,草本层 :样带 1>样带 3>样带 2 ;不同坡向的多样性 ,灌木层 :阴坡 >半阴半阳坡 >阳坡 ,草本层 :半阴半阳坡 >阴坡 >阳坡 ;不同坡形上的多样性 ,无论是灌木层还是草本层 ,多样性大小为凹坡 >平坡 >凸坡 ;
The α diversity of plant community is one of the major components of ecosystem functions. It was influenced by many environmental factors, such as soil and topographic characteristics .Conversely, plant community diversity patterns also influence the soil characteristics. The upper reaches of Minjiang River located in southwestern China is a ecological fragile transition zone from the Qinghai-Tibet Plateau to Sichuan basin. Shrubs, as a main vegetation type in this area, play a vital role in regional environmental protection. Therefore, it is important to examine the relationships between plant diversity and environmental factors to understand the process of ecosystem dynamics. This paper reports a field study on shrub community diversity in the area. Canonical correlation analysis among vegetation ,soil and topography factors shows that significant correlation exists between each pair of the variables. Altitude and slope direction have great influences on total nitrogen, organic matter, soil water, species diversity in the shrubs layer and shrubs layer coverage, while species diversity in the shrubs layer and shrubs coverage is closely related to the total nitrogen, organic matter, and soil water content. Species diversity in both the herbs layer and shrubs layer are increased at first, then decreased, and then increased with the increase of altitude. Species diversity in the herb layer is higher than that in the shrub layer, and changes of species diversity in the herbs layer is greater than that in the shrubs layer. Both herbs layer and shrubs layers have high species diversity from at the 1400～1600 m and 2000～2200 m altitudes. Species diversity of different plant formations indicates that Pertya sinensis-Jasminum humile Formation, Berberis wilsonae,Lonicera japonica Formation and Spiraea Spp. Formation have higher species diversity. The Leptodermis purdomi Formation, Caryopteris spp. Formation and Bauhinia faberi-Sorphora vrcifolia Formation have lower species diversity. Ranks of the species diversity in different transects varied as follows: for shrubs layer ,transect3> transect1> transect2; and for herbs layer, transect1> transect3> transect2. The variance of community species diversity in different slope directions ranked as shrubs layer, shaded slope> half sunny and half shaded slope>sunny slope, herbs layer, half sunny and half shaded slope> shaded slope>sunny slope. The variance of community species diversity in different slope shape and slope position indicated the following ranking at both in shrub layers and herb layers: concave slope>straight slope >convex slope,upper slope>middle slope>lower slope.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第6期1123-1130,共8页
Acta Ecologica Sinica
基金
国家重点基础研究发展规划资助项目 (G2 0 0 0 0 4680 7)~~
关键词
岷江干旱河谷
植物群落
Α多样性
环境因子
典范相关分析
the arid valley of Minjiang River
plant community
α diversity
environmental factors
canonical correlation analysis
