十种濒危植物的种群生态学特征及致危因素分析

Population Ecological Characteristics and Analysis on Endangered Cause of Ten Endangered Plant Species

从保护生态学的观点出发 ,对 1 0个濒危植物的地理分布、生境条件、种群数量动态、空间分布格局、种间关系、种群的生命表、生殖力表、有性生殖、无性繁殖等种群生态学特征进行了综合分析。论述了濒危植物以光合、蒸腾、呼吸为主的生理生态学规律 ;预测种群数量动态的 Leslie矩阵、刻画种群空间分布格局的模型、刻画种群生长和数量增长的 Logistic方程和多元回归模型所反映出的生态学特征。分析了濒危植物种群动态、发展趋势以及在内外因素作用下的生态学特征和过程。针对濒危植物保护研究存在的问题 ,从生态学角度对我国未来濒危植物保护研究应注意的问题提出了建议。

The conservation biological study on 10 typical endangered plant species (Cycas panzhihuaensis,Cathaya argyrophylla,Liriodendron chinense,Paeonia suffruticos subsp. Spontanea,Cimicifuga nanchuanensis,Eleutherococcus brachypus,Mosla hangzhouensis,Adenophora lobophlla,Ranalisma rostratum,Ophiopogon xylorrhizus) from China were carried out with the same aim and research method, supported by the key important projects of the National Natural Science Foundation of China during the period of the 8 th five year plan(1993～1997), and many kinds of the results were published. In order to get some information on common regulations on the endangered ecological process and the biological characteristics of tendency to endangered status, the geographic distribution, the habitat conditions, the population dynamics, the characteristics of sexual reproduction and asexual propagation of 10 endangered species were reviewed comprehensively. The common regulations such as photosynthesis, transpiration, respiration of the endangered plants in the different conditions were discussed. The modeling of the Leslie matrix, time series analysis for predicting population dynamics, fractal theory for describing population distribution pattern, equations of Logistics for population growth of 10 endangered plant populations were comprehensively explained. From the comprehensive analysis, general population ecological regulations of the endangered plants were summarized, and some of the regulations or characteristics that were unclear or did not appeared from the solitary study for one species, were clear.(1) The distribution areas of the endangered plant species belonged to the shape of island or strait area which all were contracting; (2) The analysis on age structure of the endangered species indicted that most populations had declining status and their spatial distribution patterns were a conglomeration; (3) Normally the adapting and living abilities of the most endangered species were not stronger than the widespread species; (4) The endangered species in communities showed the worse position among species competitions and their competitive abilities were weaker compared with other widespread species; (5) For most endangered species, the seed yields were lower, the seed quality was worse, and the death rates from seeds developing to seedlings in a natural soil seed bank were higher than other species; (6) The asexual propagating of the endangered species were a kind of compensation for maintaining population development after sexual reproduction failure, however, its functions for population to evolve and adapt were limited; (7)The favorable influence from other living things to engendered species was weaker, whereas the unfavorable influence was stronger in natural situations because the original balance of the ecosystems were broken and the biodiversity was reduced; (8) The predicting model analysis of the populations showed that most endangered population are in declining status. The inner factors, such as feeble living and reproductive ability that led species to be in an endangered status were vital reason. The external factors, such as disturbance from humans played a role to promote the endangered ecological process. However,when disturbance from human was too strong, the external factors would become the vital reason for the plant species to go extinct. According to the common biological characters of the endangered plants and their conservation in China, the research on technology, strategies and measurements of conservation should be strengthened and the more endangered plant species should be studied; disturbance from human such as digging, cutting off, reclamation of land and over grazing etc. should be stopped; the ecosystem conservation and the in situ conservation of endangered plants should be top priority; ex situ conservation of endangered species will be carried out when the number of population in fields go down to the limitations or the suitable environmental is vanished.