病原体和昆虫食草动物驱动热带雨林的植物多样性和组成
Robert Bagchi1, Rachel E Gallery2, Sofia Gripenberg3
11] Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [2] Ecosystem Management Group, Institute of Terrestrial Ecosystems, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland.
Nature
|January 28, 2014
概括
特殊的自然敌人,如真菌和昆虫,通过增加高植物密度的死亡率来维持热带森林的生物多样性. 这项研究证实了Janzen-Connell假设,表明这些生物对于构建植物群落和保护多样性至关重要.
科学领域:
- 热带生态 热带生态
- 社区生态学社区生态学
- 生物多样性科学是生物多样性的科学.
背景情况:
- 热带森林拥有巨大的生物多样性,但维持它的机制尚未完全理解.
- 詹森-康奈尔假设认为,专门的自然敌人 (昆虫,病原体) 导致负密度依赖 (NDD),促进物种共存.
- 虽然观察到NDD,但其在维护热带植物多样性的全社区作用仍然未经实验验证.
研究的目的:
- 在热带植物群落中实验测试詹森-康奈尔假设.
- 确定真菌病原体和昆虫食草动物在构建植物群落和维持多样性的作用.
- 调查NDD如何影响幼苗招募和物种组成.
主要方法:
- 在热带森林环境中对真菌病原体 (使用杀菌剂) 和昆虫食草动物 (使用杀虫剂) 的实验性操纵.
- 监测植物物种多样性和组成的变化,在种子到种子的过渡过程中.
- 评估种苗招募率和同类种子密度对NDD的影响.
主要成果:
- 杀菌剂治疗显著减少了幼苗的多样性,支持了Janzen-Connell假设.
- 杀虫剂处理并没有改变多样性,但增加了幼苗招募和变化的物种组成.
- 证实了NDD,在高同类种子密度下减少招募,特别是对于丰富的物种.
- 抑制真菌减少了对招募的密度依赖性影响,突出显示了真菌通过NDD在维护多样性的作用.
结论:
- 这项研究提供了强有力的实验证据,支持热带森林中的Janzen-Connell假设.
- 菌病原体通过NDD在维持热带植物多样性方面发挥着至关重要的作用.
- 昆虫和病原体是构建热带植物群落和保护其特殊生物多样性的关键驱动因素.
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