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小幅度循环源于多夫尼藻系统中阶段结构相互作用
Edward McCauley1, William A Nelson, Roger M Nisbet
1Ecology and Evolution Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada. mccauley@ucalgary.ca
Nature
|October 31, 2008
概括
生态理论预测了大量的人口循环,但许多人群是稳定的. 这项研究揭示了消费者发展和死亡率如何在消费者资源系统中产生稳定,小幅度的周期以及更大的波动.
科学领域:
- 生态生态学 生态生态学
- 理论生态学理论生态学
- 人口动态 人口动态
背景情况:
- 生态理论经常预测来自消费者与资源相互作用的大型人口周期.
- 然而,许多自然种群表现出稳定性或小幅度波动,创造了一个理论上的悖论.
- 消费者的延迟反机制理论上可以产生大幅度循环,即使与资源脱.
研究的目的:
- 为了调和大人口周期的理论预测与观察到的人口稳定性之间的差异.
- 调查特定消费者特征,即资源依赖性死亡率和发育迟缓,如何影响人口周期动态.
- 提出一个新的理论框架,解释消费者资源系统中小幅度和大幅度周期的共存.
主要方法:
- 开发了一种理论模型,将资源依赖性死亡率和消费者的动态发育迟缓纳入其中.
- 分析了小振幅周期出现并与大振幅周期共存的条件.
- 进行生物测试实验,测量不同周期类型的种群的个体生长率,以测试理论预测.
主要成果:
- 确定了一种新型的小幅度周期,由资源依赖性死亡率和动态发育延迟驱动.
- 证明,当消费者的发育延迟超过周期期时,就会发生小幅度周期.
- 观察到,当周期期超过发育迟缓时,会出现大幅度周期.
- 达芬尼亚藻系统的实验结果与理论预测一致.
结论:
- 资源依赖的青少年发育持续时间和资源依赖的死亡率是产生小幅度资源消费周期的关键因素.
- 小幅度和大幅度周期的共存可以通过发育延迟和周期周期之间的相互作用来解释.
- 这种机制可以解释在许多自然种群中观察到的小幅度波动的普遍性.
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