珍稀濒危植物金丝李的生境特征及致濒原因分析

The Habitat Characteristics and Analysis on Endangering Factors of Rare and Endangered Plant Garcinia paucinervis

采取查阅资料、走访和实地调查相结合的方法,调查了金丝李(Garcinia paucinervis)的地理分布、生境和资源现状,对其分布区气候特征、土壤营养状况和群落植被等进行分析;采用主成分分析法,找出影响金丝李分布的主要环境因子与群落特征因子,并探讨金丝李的致濒原因,为金丝李种质资源的有效保护、引种驯化等提供科学依据。结果表明,(1)金丝李主要分布在广西西北部、西南部、南部和云南东南部的石灰岩岩溶地貌山地上,跨越北纬22°27′58″~25°9′10″、东经103°55′58″~108°40′3″,海拔在194~830 m之间,其中海拔200~400 m分布较为常见。大多分布点位于山体的中、下部,坡度多为35~45°,分布较集中,且多为生境保持良好之地,种群内个体一般不到100株,大树和有结实的植株极少。(2)金丝李多分布在年均温20~22℃范围地区内,性喜暖热、雨量充沛的环境,喜疏松、湿润的中性或微碱性石灰土,肥力中等以上。(3)金丝李群落植被状况良好,植物种类多样,桂西北的群落有亚热带性质;桂西南、桂南和滇东南的群落则富有热带性质。(4)金丝李在资源的竞争中难以取得优势地位;群落植被遭到破坏,生境受人为干扰严重;各种群在不同年龄层次断层,种子萌发率低,种群天然更新能力弱等为金丝李濒危的主要原因。

In order to provide scientific basis for effective protection, introduction and domestication of G. paucinervis resources, its geographical distribution, habitat and resource status were studied through literature, interview and field investigations; ecological environment, climatic characteristics, soil nutrient and vegetation components were statistically analyzed; Principal component analysis （PCA） was used to find out the main environmental factors and community characteristics factors affecting the distribution of G. paucinervis, and the main influencing factors of endangerment were explored. Main results are as follows： （1） G. paucinervis is distribution in the limestone karst landform region in northwest, southwest, south Guangxi and southeast Yunnan, with area from 22°27′58″~25°9′10″N, 103°55′58″~108°40′3″E. Vertical level of G. paucinervis is at the elevation from 194~830 m, Among which, the elevation of more distribution areas are 300~400 m. Most of the distribution points are middle and lower position of slopes, and more of which are steep slopes of 35~45°. Most of distributions were well maintained habitat, where the individuals are concentrated and most of individual number are below 100. DBH over 50 cm trees and fruiting individuals are rare. （2） A substantial part of mean annual temperature of distributions are range from 20~22 ℃. The plant is a tropical species which like warm climate, which is suitable for loose, moist neutral or slightly alkaline lime soil. （3） G. paucinervis can coexist with many vegetative plants of tropical species. The community in northwest Guangxi contains subtropical character, and which in southwest, south Guangxi, and southeast Yunnan contains tropical character. （4） The main causes of endangerment： Difficult for G. paucinervis to gain the advantage in the competition of resources; the destroyed vegetation of the community and the habitat seriously disturbed by human beings; faults of different ages in various groups, the low seed germination rate and the weak natural regeneration ability.