Karasiewicz Stéphane, Dolédec Sylvain, Lefebvre Sébastien
UMR 8187 LOG (Laboratoire d'Océanologie et Géosciences), CNRS, Université des Sciences et Technologies de Lille (Lille I), ULCO, Wimereux, Nord-Pas-de-Calais, France.
UMR 5023 LEHNA (Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés), Biodiversité et Plasticité dans les Hydrosystèmes, Université Claude Bernard (Lyon I), Villeurbanne, Rhône, France.
PeerJ. 2017 May 23;5:e3364. doi: 10.7717/peerj.3364. eCollection 2017.
The ecological niche concept has regained interest under environmental change (e.g., climate change, eutrophication, and habitat destruction), especially to study the impacts on niche shift and conservatism. Here, we propose the within outlying mean indexes (WitOMI), which refine the outlying mean index (OMI) analysis by using its properties in combination with the -select analysis species marginality decomposition. The purpose is to decompose the ecological niche into subniches associated with the experimental design, i.e., taking into account temporal and/or spatial subsets. WitOMI emphasize the habitat conditions that contribute (1) to the definition of species' niches using all available conditions and, at the same time, (2) to the delineation of species' subniches according to given subsets of dates or sites. The latter aspect allows addressing niche dynamics by highlighting the influence of atypical habitat conditions on species at a given time and/or space. Then, (3) the biological constraint exerted on the species subniche becomes observable within Euclidean space as the difference between the existing fundamental subniche and the realized subniche. We illustrate the decomposition of published OMI analyses, using spatial and temporal examples. The species assemblage's subniches are comparable to the same environmental gradient, producing a more accurate and precise description of the assemblage niche distribution under environmental change. The WitOMI calculations are available in the open-access R package "subniche."
在环境变化（如气候变化、富营养化和栖息地破坏）的背景下，生态位概念重新受到关注，尤其是用于研究对生态位转移和保守性的影响。在此，我们提出了离群均值内指标（WitOMI），它通过结合其特性与 - 选择分析物种边缘性分解来完善离群均值指标（OMI）分析。目的是将生态位分解为与实验设计相关的子生态位，即考虑时间和/或空间子集。WitOMI强调有助于（1）利用所有可用条件定义物种生态位，同时（2）根据给定的日期或地点子集描绘物种子生态位的栖息地条件。后一个方面通过突出非典型栖息地条件在给定时间和/或空间对物种的影响来解决生态位动态问题。然后，（3）在欧几里得空间中，作为现有基础子生态位与实现的子生态位之间的差异，施加在物种子生态位上的生物约束变得可观测。我们使用空间和时间示例来说明已发表的OMI分析的分解。物种组合的子生态位与相同的环境梯度具有可比性，从而能更准确、精确地描述环境变化下组合生态位的分布。WitOMI计算可在开放获取的R包“subniche”中获取。
