Duffy J Emmett, Cardinale Bradley J, France Kristin E, McIntyre Peter B, Thébault Elisa, Loreau Michel
School of Marine Science and Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, VA 23062-1346, USA.
Ecol Lett. 2007 Jun;10(6):522-38. doi: 10.1111/j.1461-0248.2007.01037.x.
Understanding how biodiversity affects functioning of ecosystems requires integrating diversity within trophic levels (horizontal diversity) and across trophic levels (vertical diversity, including food chain length and omnivory). We review theoretical and experimental progress toward this goal. Generally, experiments show that biomass and resource use increase similarly with horizontal diversity of either producers or consumers. Among prey, higher diversity often increases resistance to predation, due to increased probability of including inedible species and reduced efficiency of specialist predators confronted with diverse prey. Among predators, changing diversity can cascade to affect plant biomass, but the strength and sign of this effect depend on the degree of omnivory and prey behaviour. Horizontal and vertical diversity also interact: adding a trophic level can qualitatively change diversity effects at adjacent levels. Multitrophic interactions produce a richer variety of diversity-functioning relationships than the monotonic changes predicted for single trophic levels. This complexity depends on the degree of consumer dietary generalism, trade-offs between competitive ability and resistance to predation, intraguild predation and openness to migration. Although complementarity and selection effects occur in both animals and plants, few studies have conclusively documented the mechanisms mediating diversity effects. Understanding how biodiversity affects functioning of complex ecosystems will benefit from integrating theory and experiments with simulations and network-based approaches.
了解生物多样性如何影响生态系统功能需要整合营养级内的多样性（水平多样性）和跨营养级的多样性（垂直多样性，包括食物链长度和杂食性）。我们回顾了在这一目标上的理论和实验进展。一般来说，实验表明，生物量和资源利用随着生产者或消费者的水平多样性而以相似的方式增加。在猎物中，较高的多样性通常会增加对捕食的抵抗力，这是因为包含不可食用物种的概率增加，以及面对多样猎物的专性捕食者的效率降低。在捕食者中，多样性的变化可能会级联影响植物生物量，但其影响的强度和方向取决于杂食性程度和猎物行为。水平和垂直多样性也相互作用：增加一个营养级可以定性地改变相邻营养级的多样性效应。多营养级相互作用产生的多样性 - 功能关系比单一营养级预测的单调变化更加丰富多样。这种复杂性取决于消费者饮食的泛化程度、竞争能力与抗捕食能力之间的权衡、集团内捕食以及迁移的开放性。虽然互补效应和选择效应在动物和植物中都存在，但很少有研究能确凿地记录介导多样性效应的机制。将理论和实验与模拟和基于网络的方法相结合，将有助于理解生物多样性如何影响复杂生态系统的功能。
