| 摘要: |
| 物种的灭绝本是一个自然过程，但人类的繁荣使数以百万计的生物物种的栖息地被蚕食，很多物种以惊人的速度灭绝了（如长江中的白鱀豚和白鲟）或正在绝灭之中（中华鲟），但却未伴随新物种的自然产生.世界自然保护联盟虽然确定了物种濒危的等级标准，但定量划分标准的象征意义大于实际意义，因为不可能所有生物物种都能通过同一种种群动态模式去预测它们未来的命运.关于物种的濒危机制，人们提出了许多基于种群数量变动的理论概念（如最小生存种群、有效种群大小、种群瓶颈、奠基者效应、“阿利”效应、灭绝漩涡等），但可操作性不强，对保护生物学的实际指导意义不大.本文提出了物种生存状态转化的概念模型，物种生存状态主要取决于物种对外在环境的综合生存适合度f（s）和灭绝风险R，受到①物种生存空间的完整性、②生态过程的适宜性、③食物的可得性、④对人为致死或自然灾害的抵抗力等的影响.f（s）由物种对若干决定性生存因子s1、s2、s3…的适合度之乘积所决定：f（s）=f（s1） f（s2） f（s3） ……，f（s）取值0~1，1表示最大的适合度（理想生存状态），0表示彻底丧失了适合度，因此，任何一个决定性生存因子的趋零，都会导致该物种的灭绝（木桶效应）.物种的生存状态指数H（f，R）由f（s）和R联合决定.可用f（s）来评估与预测物种的灭绝风险（譬如，可区分为3~4个风险等级），突变临界点之前的动态过程可作为物种濒危的早期预警信号，物种拯救临界点可作为保护性干预的最低目标.当然，这里只是提出了一个概念模型，各个决定性生存因子的适合度函数f（s）有待确定，并需要以真实的物种为对象进行验证. |
| 关键词: 濒危物种 评估概念模型 物种生存状态指数 决定性生存因子的适合度 木桶效应 物种拯救临界点 |
| DOI：10.18307/2020.0200 |
| 分类号: |
| 基金项目:中国科学院战略先导科技专项（B类）（XDB31000000）资助. |
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| How to evaluate and rescue endangered species? |
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XIE Ping1,2
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1.Donghu Experimental Station of Lake Ecosystems, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China;2.Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, P. R. China
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| Abstract: |
| Extinction of species is a natural process, yet human prosperity has eroded the habitats of millions of species, as a result, many species have disappeared (e.g., white-flag dolphin, Chinese paddlefish) or is going into extinction (e.g., Chinese sturgeon), but without coming of new species. Although the IUCN has established the quantitative standard of endangered species, it is more symbolic rather than practical, as it is impossible for all species to predict their future fates only through the same population dynamic model. On the endangered causes of species, there have many theoretical concepts based on the dynamics of population density (such as minimum viable population, effective population size, population bottleneck, founder effect, Allee effect, extinction vortex), which generally have poor operability, and thus is of little significance to the practical guidance of conservation biology. In this paper, a conceptual model of regime shift of species status is proposed. Species status depends on its composite survival fitness f(s) and extinction risk (R) to external environments, which are affected by integrities of living space and ecological processes, food availability, and resistance to fatal artificial or nature disasters. f(s) is determined by the product of the fitness of several determinant survival factors (s1, s2, s3……):f(s)=f(s1) f(s2) f(s3)……, and f(s) takes values of 0-1, with 1 being the maximum fitness (ideal status) but with 0 being complete absence of fitness. Therefore, zeroing of any determinant survival factor f(s) would indicate species extinction (buckets effect). Index of species status [H(f, R)] is determined by f(s) and R. f(s) can be used to assess and predict the extinction risk of species (e.g., it can be divided into 3-4 risk levels), the dynamics or processes before the critical point can be used as an early warning signal of speceis extinction, and the tipping point of species rescuing can be regarded as the lowest target of protective intervention. Of course, here is just a conceptual model, and each f(s) still needs to be detemined and tested by data from real species. |
| Key words: Endangered species conceptual model of estimation index of species status fitness of determinant survival factor buckets effect tipping point for species rescuing |
