广州红锥-马占相思林物种组成与多样性研究

Studies on Species Composition and Diversity of Castanopsis hystrix-Acacia mangium Mixed Forest in Guangzhou

摘要:

为了解广州市龙眼洞林场红锥（Castanopsis hystrix）-马占相思（Acacia mangium）阔叶混交林的群落结构，对其物种多样性进行了分析。结果表明，红锥-马占相思阔叶混交林的物种丰富度依次为乔木层 > 灌木层 > 草本层 > 层间植物层。乔木层的Simpson和Shannon-Wiener指数分别为0.945和0.237，密度为2 671 ind./hm²，红锥、马占相思、三桠苦（Melicope pteleifolia）、山乌桕（Triadica cochinchinensis）和台湾相思（A. confusa）的重要值较高。灌木层中豺皮樟（Litsea rotundifolia var. oblongifolia）、九节（Psychotria asiatica）、黄牛木（Cratoxylum cochinchinense）的重要值超过10%。层间植物的优势科为茜草科（Rubiaceae），其次是夹竹桃科（Apocynaceae）。草本层植物密度约38 000 ind./hm²，以禾本科（Poaceae）占优势，有9种。红锥林从幼龄向中龄过渡，优势种群为增长型，而马占相思林则由近熟龄或成熟龄向过熟龄过渡。对不同区域4种近似林分的比较表明，混交林的生物多样性远远高于人工纯林。因此，红锥-马占相思阔叶混交林已形成了混交复层异龄林结构，乔木层、灌木层和草本层均具有较高的物种丰富度。

Abstract:

In order to understand the community structure of Castanopsis hystrix and Acacia mangium broad-leaved mixed forest in Longyandong Forest Farm in Guangzhou, its species diversity was analyzed. The results showed that the species richness was in the order of tree layer > shrub layer > herb layer > interlayer plant layer. The Simpson and Shannon-Wiener indices of tree layer were 0.945 and 0.237, respectively, with the density of 2 671 ind./hm². Castanopsis hystrix, A. mangium, Melicope pteleifolia, Triadica cochinchinensis and Acacia confusa had high importance values of 12.79%, 10.98%, 8.08%, 7.78% and 7.02%, respectively. Among the 35 shrub species, the important values of Litsea rotundifolia var. oblongifolia (14.95%), Psychotria asiatica (12.60%) and Cratoxylum cochinchinense (10.17%) were more than 10%. The dominant family of interlayer speciess was Rubiaceae, followed by Apopynaceae. The density of herb species was about 38 000 ind./hm², and Poaceae was the dominant family, which consists of 9 species. Castanopsis hystrix community was transited from young age to middle age, the dominant population was growth type, while Acacia mangium community was transited from near maturity age or mature age to over maturity age. Compared with similar forests in different region, the biodiversity of mixed forest was much higher than that of pure forest. Therefore, C. hystrix-A. mangium broad-leaved mixed forest had formed the structure of mixed multilayer and different age forest with high species richness in tree layer, shrub layer and herb layer.