http://onlinelibrary.wiley.com/doi/10.1111/ele.12088/abstract

Ecology Letters (2013) 16: 617–625

Predicting ecosystem stability from community composition and biodiversity

As biodiversity is declining at an unprecedented rate, an important current scientific challenge is to understand and predict the consequences of biodiversity loss. Here, we develop a theory that predicts the temporal variability of community biomass from the properties of individual component species in monoculture. Our theory shows that biodiversity stabilises ecosystems through three main mechanisms: (1) asynchrony in species’ responses to environmental fluctuations, (2) reduced demographic stochasticity due to overyielding in species mixtures and (3) reduced observation error (including spatial and sampling variability). Parameterised with empirical data from four long-term grassland biodiversity experiments, our prediction explained 22–75% of the observed variability, and captured much of the effect of species richness. Richness stabilised communities mainly by increasing community biomass and reducing the strength of demographic stochasticity. Our approach calls for a re-evaluation of the mechanisms explaining the effects of biodiversity on ecosystem stability.

由于生物多样性正在以前所未有的速度减少，当前一个重要的科学难题是理解和预测生物多样性丧失的后果。本文中我们提出一个根据单种栽培情况下物种的个体属性预测群落生物量的随时间变化的理论。该理论表明生物多样性通过3中主要的机制来稳定生态系统：1）不同物种对环境波动反应的不同时性， 2）物种混合情况下每个物种都会比单一种植情况下产量高（生物量、种子产量、幼苗数量）降低物种种群结构和大小的随机性，3）减少观测误差（包括空间和取样的变异性）。我们的模型用4个长期的草地生物多样性试验数据得到的参数预测的结果解释了22－75％的观测变异并且代表了物种丰富度的大部分效应。物种丰富度主要靠增加群落生物量和减少种群随机变化来稳定群落。我们的方法说明需要从新评估解释生物多样性对生态系统稳定性影响的各种机制。