【摘要】 为探讨珙桐(Davidia involucrata)在群落中的作用,及其与土壤因子的关系,研究了四川卧龙自然保护区白泥岗地带不同海拔高度的珙桐群落主要物种重要值及其根际土壤性质.结果表明,该地区珙桐重要值最大,是群落优势种,却是一个处于衰退的种群,1 500-1 700m是该地区最适宜珙桐生长的海拔高度.珙桐根际土壤各指标在三个土层深度间差异显著;整个地区土壤pH值变化范围小;腐殖质层土壤指标1 500m、1 600m和1 700m三个海拔显著高于1 800m和1 850m两个海拔;沉积层和母质层两层在5个海拔间的变化规律性不强.相关分析表明,珙桐重要值与速效磷和有机质的相关性均不显著;幼树重要值与pH值的相关性随土层的加深而增强而成树重要值与含水量的相关性随土层的加深而增强;A层土壤指标速效氮和速效钾与珙桐重要值相关性最强,它们可能是珙桐生长的限制因子.更多还原

【Abstract】 In order to study the status of D-involuarata in its community and its connection with the soil characteristics,the author have studied the important value of major species and the soil chemical properties of D-involucrata communities roots in Wolong Nature Reserve.The result shows that D-involucrata is the constructive specie in the community as its important value is the highest in the all species,but it is a recessionary specie.The altitudes between 1500m and 1700m are fit for the growth of Davidia involucrate the most.Differences of soil chemical properties among the three layers of soil section are obvious.As to the soil characteristics of humus horizon,the value of the three altitudes from 1500m to 1700m is obviously higher than that of 1800m and 1850m.It is hard to summarize the variety rule of illuvial horizon and parent material horizon.The relationship analysis shows that,the relationship between D-involucrata important value and the available phosphorous or the organic matte is not obvious.The relationship between the important value of D-involucrata infancies and pH is swelled as the deeper of soil while the relationship between the important value of D-involucrata majors and moisture content is swelled as the deeper of soil.The available nitrogen and available potassium of layer A are strongly corrected with the D-involucrata important value and they may be t he limiting factor of D-involucrata growth.更多还原