Rheagogies: Modelling non-trophic effects in food webs
Rheagogies: Modelling non-trophic effects in food webs
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DOI：
10.1016/j.ecocom.2005.04.003
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发表时间：
2005-09-01
影响因子：
3.5
通讯作者：
Hirzel, AH
中科院分区：
文献类型：
--
作者：
Arditi, R;Michalski, J;Hirzel, AH
在食物网中，营养物质通过营养链流动。因此，由于质量守恒原理，营养相互作用具有一个基本特征。为了进一步遵守这一原则，我们考虑了一个包括营养循环的食物网模型。食物网中物种之间的非营养效应被建模为相互作用的变化，即由第三种物种引起的两种物种之间营养相互作用的功能变化（我们称之为“流变”的三方相互作用）。我们还认为，以食物网为模型的生态群落是一个包括殖民化和灭绝的组装过程的结果。我们发现必须区分两类不同的生态群落：(a)“超高效”群落，其中几乎所有可用的营养物质都被纳入生物量；(b)“亚高效”群落，其中大部分营养物质不是由生物体固定的。我们表明变异（模拟非营养相互作用）是至关重要的：变异的影响越大，就越容易建立超高效的社区。这些社区的特点是积极的流变，这意味着一定比例的互惠互动是必要的。屈变性少或弱的系统不太可能有效地利用可用的非生物资源。虽然丰富度（即物种数量）也与养分的有效利用呈正相关，但其重要性远小于变异率。(C) 2005 Elsevier B.V.版权所有
In a food web, nutrients flow via trophic links. For this reason, trophic interactions have a fundamental character due to the principle of mass conservation. To further comply with this principle, we consider a food web model that includes nutrient cycling. Non-trophic effects amongst species of the food web are modelled as interaction modifications, i.e., a functional change in the trophic interaction between two species caused by a third species (a three-party interaction that we call "rheagogy"). We also consider that the ecological communities modelled by the food webs result from an assembly process that involves colonisations and extinctions. We find that two distinct classes of ecological communities Must be distinguished: (a) "super-efficient" communities, in which almost all available nutrients are incorporated into the biomass and (b) "sub-efficient" ones, in which a large proportion of nutrients is not fixed by living organisms. We show that rheagogies (that model non-trophic interactions) are crucial: the larger the effects of rheagogies, the easier the construction of super-efficient communities. These communities are characterized by positive rheagogies, meaning that a certain proportion of mutualistic interactions is necessary. Systems with few or weak rheagogies are less likely to use available abiotic resources efficiently. Although richness (i.e., number of species) is also positively related to efficient nutrient use, its importance is much smaller than that of rheagogies. (C) 2005 Elsevier B.V. All rights reserved.