本文排版定稿已在中国知网网络首发,如需阅读全文请打开知网首页,并搜索该论文题目即可查看。
极小种群植物独龙江空竹资源与群落结构特征研究
Investigation on the Resource Status and Vegetation Community of Cephalostachyum mannii, a Plant with Extremely Small Population
-
摘要: 通过对极小种群植物独龙江空竹开展系统的野外调查,并结合相关文献资料整理,首次查清了独龙江空竹的资源现状与群落状况,阐明了其地理分布与生境特征,提出了具体的保护管理建议。结果表明:独龙江空竹在中国仅分布于滇西北贡山县独龙江乡马库村、巴坡村的独龙江两岸狭小区域,垂直分布海拔
1241 ~1480 m,野外种群有11个分布点、162丛9909 根,分布面积26.05 hm2,野外分布范围狭窄,现存种群及植株数量少,种群呈“点状”或间断“岛状”分布,种群孤立分布较明显。生境位于江边和山坡下部陡坡、急坡、险坡,且悬崖峭壁较多的区域;11个分布点中,仅有2个分布点在保护区内,保护空缺较大;生境受垦植、公路建设、采伐等人为干扰影响较大,生境破碎化较严重,生存状态堪忧。独龙江空竹在多数群落中为第二乔木层的伴生树种,群落分布面积小,偶见的以其为单优势种的群落是上层植被遭破坏后形成的,但群落内保护物种较多,科研保护价值较高。独龙江空竹所处植被有3个植被型3个植被亚型6个群落,群落垂直结构明显,有乔木、灌木、草本3层,各层盖度分别为35%~65%、15%~50%、30%~75%。独龙江空竹植被群落物种丰富,在2400 m2的样地内,共有维管植物51科88属104种,樟科、禾本科等8个科占优势,含42种植物,占科总数的15.69%,占种总数的40.39%,表明群落物种丰富、优势科地位显著。调查的6个样地中有5个样地的Simpson多样性指数、Pielou均匀度指数大于0.9,Shannon-Wiener 多样性指数大于3.0,表明群落的物种丰富且分布较均匀。Abstract: Cephalostachyum mannii is a wild plant with an extremely small population, urgently requiring enhanced conservation efforts. However, current knowledge about its resource status and community conditions is limited, severely hindering the formulation and implementation of conservation plans. Through systematic field investigations and literature review, this study, for the first time, clarified the resource status and community conditions of this species, elucidated its geographical distribution and habitat characteristics, and proposed specific conservation and management recommendations. The results are as follows: (1) C. mannii is exclusively distributed in China within a narrow area along both banks of the Dulong River in Maku Village and Bapo Village, Dulongjiang Township, Gongshan County, northwest Yunnan, at elevations ranging from 1,241 to 1,480 meters. The wild population comprises 11 distribution points with 162 clumps and 9,909 stems, covering an area of 26.05 hectares. The wild distribution range is narrow, with a small number of existing populations and individual plants. The populations exhibit a "patchy" or discontinuous "island-like" distribution, with significant isolation among populations. (2) The habitats are located along riverbanks and on steep, abrupt, and precipitous slopes at the lower parts of hillsides, characterized by numerous cliffs. Among the 11 distribution points, only two are within protected areas, indicating a substantial conservation gap. The habitats are significantly impacted by human disturbances such as cultivation, road construction, and logging, leading to severe habitat fragmentation and a concerning survival status. (3) C. mannii serves as an associated tree species in the second arbor layer in most communities. These communities have a small distribution area. Occasionally, communities with C. mannii as the single dominant species are formed after the destruction of the upper vegetation layer. However, these communities contain a relatively large number of protected species and hold high scientific research and conservation value. (4) The vegetation where C. mannii occurs comprises three vegetation types, three vegetation subtypes, and six communities. The vertical structure of the communities is distinct, consisting of three layers: trees, shrubs, and herbs, with coverage rates ranging from 35-65%, 15-50%, and 30-75%, respectively. (5) The vegetation communities of C. mannii are species-rich. Within a 2,400 m sample plot, there are 104 vascular plant species belonging to 88 genera and 51 families. Eight families, including Lauraceae and Poaceae, are dominant, accounting for 42 species, representing 15.69% of the total families and 40.39% of the total species, indicating a rich species composition and prominent status of dominant families within the community. (6) Among the six sample plots surveyed, five have Simpson diversity indices and Pielou evenness indices above 0.9, and Shannon-Wiener diversity indices above 0.3, indicating that the communities are species-rich and exhibit relatively even species distribution.
下载: