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南方红豆杉为国家Ⅰ级重点保护植物,山西省东南部为其自然分布最北界.本文调查了南方红豆杉在山西省的野生分布,对其进行了群落划分、物种多样性、结构特征和竞争特性的研究.结果表明:山西省南方红豆杉主要形成南方红豆杉+鹅耳枥群落、南方红豆杉-荆条群落、南方红豆杉-海州常山群落和南方红豆杉+栓皮栎群落,集中分布于陵川县磨河和阳城县蟒河自然保护区,其他地区均为散生;群落垂直结构明显,南方红豆杉已进入主林层,混交林林冠层高8~10 m,纯林高5~6 m;群落间的总体物种多样性指数和均匀度指数存在显著差异.南方红豆杉植株矮小,平均高5.16 m,乔木层、演替层分别占43.4%和56.6%,更新层缺乏;胸径<16 cm的个体占67.6%,胸径32~40 cm的个体占4.0%,幼苗稀少,仅发现4株幼苗;大量的小径级个体虽可保证南方红豆杉在一定时间内维持稳定的种群结构,但幼苗缺失必将引起未来种群的衰退.山西省野生南方红豆杉分布相对集中,多数是小径级个体,导致其种内竞争激烈,种内竞争强度占61.8%;鹅耳枥和栓皮栎是研究地区的主要组成树种,对南方红豆杉造成的种间竞争压力最大.
Taxus chinensis is a national grade I protected plant and southeastern Shanxi is the northernmost part of its natural distribution.This paper investigated the wild distribution of Taxus chinensis in Shanxi Province and classified its community diversity, The results showed that the main forms of Taxus chinensis var. Mairei community, Taxus chinensis var. Chinense community, Taxus mairei-Haizhou Changshan community and Taxus chinensis + Quercus variabilis community were concentrated in the distribution of Taxus chinensis The vermilion trees in Mulinghe, Lingchuan County and Manghe Nature Reserve in Yangcheng County are scattered in other areas. The vertical structure of the community is obvious. Taxus chinensis has entered the main forest layer. The canopy height of the mixed forest is 8-10 m and the height of the pure forest is 5 ~ 6 m, there was a significant difference in the overall species diversity index and evenness index between the two communities. The S. dipsaci was short and with an average height of 5.16 m, the tree layer and the succession layer accounted for 43.4% and 56.6%, respectively, <16 cm individuals accounted for 67.6%, DBH individuals 4.0%, seedlings sparse, only 4 seedlings were found; a large number of small-diameter individuals can ensure that the South Taxus in a certain period of time to maintain a stable population structure, But the seedlings are missing Will cause the recession of the future population.The distribution of wild Taxus chinensis in Shanxi Province is relatively concentrated, most of them are small-diameter individuals, leading to intense competition within species and 61.8% of intraspecific competition intensity; Carpinus hornbeam and Quercus variabilis are the main components of the study area Species, the taxonomy of southern yew caused the greatest pressure.