钦州湾不同立地类型红树林的生长评价

Evaluation of mangrove growth in different site types in Qinzhou Bay

在不同立地类型设定样方进行调查,对比分析了钦州湾14个立地类型红树林的生长情况,同时测定了立地土壤有机质、速效N等7个因子,进行主成分分析、聚类分析、相关分析和逐步回归分析。结果表明:(1)不同立地类型土壤因子不同,影响红树林生长的主要土壤因子是全盐量、速效N和pH值;(2)不同立地类型红树林的生长不同,种类、及群落覆盖度和更新层也存在一定差异。无瓣海桑在类型3中生长较好,秋茄在类型13中生长较好,桐花树在类型1、类型5、类型11、类型13和类型14中生长良好,白骨壤在类型11、类型13和类型14中生长好;(3)红树林生长指标与部分土壤因子之间存在显著的相关性;(4)桐花树树高与有机质,地径与土壤密度之间,白骨壤树高与土壤密度,地径与土壤密度、速效K、全盐量,以及冠幅与土壤密度之间,建立的回归方程均达到显著水平。

Mangroves on different sites in Qinzhou Bay in Guangxi were investigated for understanding their growth in relation to site- types and soil factors （organic matter, available N, etc.） through principal component analysis, cluster analysis, correlation analysis and linear regression （stepwise）, involving 14 site-types and 7 soil factors. The results show that （l） Soil factors varied dependent on the site-types, while salt content, available N and pH were the main soil factors that affected on the growth of mangraves; （2） Different site- types had specific predominant species, specific coverage and regeneration layers, with Sonneratia apertala well developed on sites of type 3, Kandelia candel on sites of type 13, A egiceras corniculatum on type 1, 5, 11, 13 and 14 and Avicennia marina on type 11, 13 and 14 ; （3） The indexes of growth were significantly correlated to part of the soil factors; （4） The regression equation between the height and the organic matter ofA. corniculatum reached significant level; as well as that between the basal diameter and the soil density of A. corniculatum; between the height and the soil density of A. marina; between the basal diameter and the soil density, the available K, the salt content of A. marina; and between the crown diameter and density of A. marina.