四川喇叭河自然保护区珙桐群落特征与更新

Features and Regeneration of Davidia Involucrata Communities at Labahe Nature Reserve in Sichuan Province

在对四川喇叭河自然保护区珙桐群落进行生态学调查的基础上,着重分析了该区珙桐群落植物的物种构成、群落结构、重要值排序、Simpson指数、Shannon-Wiener指数,以及珙桐群落的生境条件、更新动态等。研究结果表明:(1)喇叭河自然保护区珙桐群落是一种典型的中亚热带中山山地常绿、落叶阔叶混交林植被;适宜分布于温暖、潮湿、雨量充沛、云雾多、日照少、山陡沟深的地段;(2)珙桐群落植物种类丰富、古老、特有性强;(3)珙桐群落垂直结构明显,珙桐构成建群种;草本层发达;(4)该地区珙桐以有性和无性繁殖更新,但有性繁殖能力很低,以无性繁殖更新为主,群落在其分布区内是一种稳定存在的群落类型。

In recent years, the increasing intensity of human activities and the increase of regional developing items led to a sharp decrease of natural distributed population number of rare and endangered species Davidia in- volucrate.Community diversity and its patterns along latitude and altitude were studied based on 3 plots samples of evergreen broadleaved forests Davidia involucrate from 3 areas iat LaBahe nature reserve.Based on the ecolog- ical survey of Davidia involucrata communities at LaBahe nature reserve, the species composition, structure, the importance values and their ranks, biodiversity of the Davidia involucrata community were analyzed mainly along with its ecotype conditions and regeneration of Davidia involucrata population.The results suggest that : (1) the nature of the community is typical of mixed evergreen deciduous broadleaf forests in mountainous region of mid- subtropics.The suitable distributive area of the community is of warm and moist habitat with abound ant rain- fall ,frequent cloud and fog and less sunlight.The land form is precipitous with deep cut valleys.(2) The species of Davidia involucrata was rich, ancient and prominently endemic.(3) The vertical structure of the com- munity is obvious.Edificatory of the community is Davidia involucrata.The field layer is developed.(4) The natural regeneration of Davidia involucrata community accomplished by seedling and tillers.But the seedling is not development unreliable.The community of Davidia involucrata here is a stable now.Although Davidia in- volucrate can maintain its existence here much stable now, the situation of its population development isn’t un- reliable.