种群多样性和被开发物种的投资组合效应
Daniel E Schindler1, Ray Hilborn, Brandon Chasco
1School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, Washington 98195-5020, USA. deschind@u.washington.edu
Nature
|June 4, 2010
概括
生物多样性稳定了生态系统. 保持鱼 (Oncorhynchus nerka) 种群多样性可以减少回归的变化,防止更频繁的渔业关闭,并支持食物网.
科学领域:
- 生态生态学 生态生态学
- 保护生物学 保护生物学
- 渔业 科学 渔业 科学
背景情况:
- 生物多样性对于稳定生态系统过程和服务至关重要.
- 投资组合效应,类似于金融投资组合,解释了多样性如何稳定社区.
- 现有的研究主要集中在物种多样性上,忽视了物种内部的多样性.
研究的目的:
- 量化来自鱼 (Oncorhynchus nerka) 种群和生命史多样性的投资组合效应.
- 评估这种多样性对生态系统服务和渔业管理的影响.
- 强调物种内部多样性对生态系统稳定的重要性.
主要方法:
- 利用了50年来在阿拉斯加布里斯托尔湾鱼的数据.
- 通过将当前系统与假设的同质人口进行比较来量化投资组合效应.
- 分析了对鱼回归和渔业关闭的波动的影响.
主要成果:
- 由于种群多样性,布里斯托尔湾鱼回归的变化率是2.2倍低.
- 一个单一的同质种群将导致渔业关闭的频率增加10倍.
- 投资组合效应还稳定了流域食物网和掠食者对资源的获取.
结论:
- 人口多样性对于稳定生态系统服务至关重要,特别是对于被利用的物种.
- 生态系统服务的可靠性随着人口的减少而更快地受到侵蚀,而不是仅仅因为物种的减少.
- 保持物种内部的多样性对于保护和可持续的经济是必不可少的.
相关概念视频
00:57Population Growth
Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.
01:19What is Biodiversity?
Biodiversity describes the variety of living things at multiple organizational levels: genetic, species and ecosystem diversity. Species diversity includes all branches of the evolutionary tree from single-celled prokaryotic organisms, bacteria, and archaea, to the eukaryotic kingdoms: plants; animals; fungi; and protists. To date, there have been about 1.75 million species identified, and new species are discovered every week.
01:09Mutation, Gene Flow, and Genetic Drift
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.
02:07Conservation of Declining Populations
Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.
03:33Genetic Drift
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.