Does functional redundancy exist?
Does functional redundancy exist?
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DOI：
10.1111/j.0030-1299.2004.12685.x
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发表时间：
2004-03-01
期刊：
影响因子：
3.4
通讯作者：
Loreau, M
中科院分区：
文献类型：
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作者：
Loreau, M
在生物多样性实验中，功能冗余通常被认为是直观的零假设，但基于经典 Lotka-Volterra 竞争模型的理论表明，严格意义上的功能冗余与稳定共存是不相容的。稳定共存需要物种之间的差异，从而导致功能互补以及混合物和单一栽培产量之间的差异。只有功能冗余的较弱版本，即混合物产量位于单一栽培产量的变化范围内，才与 Lotka-Volterra 系统中的稳定共存兼容。空间和时间环境变化可能会在小空间和时间尺度上为功能冗余提供空间，但预计不会在环境变化有助于维持共存的较大尺度上提供功能冗余。同等竞争者的中性共存、非线性人均增长率以及功能影响与生物量之间缺乏相关性可能为自然生态系统中功能冗余的存在提供了基础。总体而言，允许稳定共存的条件和允许过度屈服的条件之间存在惊人的相似之处。
Functional redundancy has often been assumed as an intuitive null hypothesis in biodiversity experiments, but theory based on the classical Lotka-Volterra competition model shows that functional redundancy sensu stricto is incompatible with stable coexistence. Stable coexistence requires differences between species which lead to functional complementarity and differences between the yields of mixtures and monocultures. Only a weaker version of functional redundancy, i.e. that mixture yields lie within the range of variation of monoculture yields, is compatible with stable coexistence in Lotka-Volterra systems. Spatial and temporal environmental variability may provide room for functional redundancy at small spatial and temporal scales, but is not expected to do so at the larger scales at which environmental variations help maintain coexistence. Neutral coexistence of equivalent competitors, non-linear per capita growth rates, and lack of correlation between functional impact and biomass may provide the basis for the existence of functional redundancy in natural ecosystems. Overall, there is a striking parallel between the conditions that allow stable coexistence and those that allow overyielding.