Tredennick Andrew T, Adler Peter B, Adler Frederick R
Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT, 84322, USA.
Departments of Biology and Mathematics, University of Utah, Salt Lake City, UT, 84112, USA.
Ecol Lett. 2017 Aug;20(8):958-968. doi: 10.1111/ele.12793. Epub 2017 Jun 9.
Theory relating species richness to ecosystem variability typically ignores the potential for environmental variability to promote species coexistence. Failure to account for fluctuation-dependent coexistence may explain deviations from the expected negative diversity-ecosystem variability relationship, and limits our ability to predict the consequences of increases in environmental variability. We use a consumer-resource model to explore how coexistence via the temporal storage effect and relative nonlinearity affects ecosystem variability. We show that a positive, rather than negative, diversity-ecosystem variability relationship is possible when ecosystem function is sampled across a natural gradient in environmental variability and diversity. We also show how fluctuation-dependent coexistence can buffer ecosystem functioning against increasing environmental variability by promoting species richness and portfolio effects. Our work provides a general explanation for variation in observed diversity-ecosystem variability relationships and highlights the importance of conserving regional species pools to help buffer ecosystems against predicted increases in environmental variability.
将物种丰富度与生态系统变异性联系起来的理论通常忽略了环境变异性促进物种共存的可能性。未能考虑依赖波动的共存可能解释了与预期的负多样性 - 生态系统变异性关系的偏差，并限制了我们预测环境变异性增加后果的能力。我们使用一个消费者 - 资源模型来探讨通过时间存储效应和相对非线性实现的共存如何影响生态系统变异性。我们表明，当在环境变异性和多样性的自然梯度上对生态系统功能进行采样时，正的而非负的多样性 - 生态系统变异性关系是可能的。我们还展示了依赖波动的共存如何通过促进物种丰富度和组合效应来缓冲生态系统功能，使其免受不断增加的环境变异性影响。我们的工作为观察到的多样性 - 生态系统变异性关系的变化提供了一个一般性解释，并强调了保护区域物种库以帮助缓冲生态系统免受预测的环境变异性增加影响的重要性。
