Berman Maïa, Andersen Alan N, Hély Christelle, Gaucherel Cédric
Ecosystem Sciences, Commonwealth Scientific and Industrial Research Organisation, Winnellie, Northern Territory, Australia ; Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia ; Unité Mixte de Recherche 0931 (botAnique et bioinforMatique de l'Architecture des Plantes), Institut National de la Recherche Agronomique, Université de Montpellier II, Montpellier, France.
PLoS One. 2013 Jun 26;8(6):e67245. doi: 10.1371/journal.pone.0067245. Print 2013.
Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites), rainforest on volcano-sedimentary soils (13), maquis shrubland (15), Melaleuca-dominated savannas (11) and Acacia spirorbis thickets (2). We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities.
蚂蚁是全球分布最广且危害最大的入侵物种之一，但针对其与栖息地及本地蚂蚁群落关系的区域研究却很少。新喀里多尼亚拥有独特且多样的蚂蚁动物群，正受到外来蚂蚁的威胁，但外来蚂蚁和本地蚂蚁群落组成与栖息地相关的广泛模式仍缺乏充分记录。我们对代表新喀里多尼亚主要栖息地类型的56个地点进行了系统的诱饵调查：超基性土壤上的雨林（15个地点）、火山沉积土壤上的雨林（13个）、灌丛林地（15个）、白千层为主的稀树草原（11个）和旋扭相思灌木丛（2个）。我们共收集到49个物种，其中13个是外来物种。只有5个地点没有外来物种，且这些地点均为雨林。最丰富的5个外来物种在栖息地关联方面存在差异，大头蚁与雨林相关，近似暗褐短猛蚁与稀树草原相关，而长足捷蚁和流浪尼氏蚁存在于大多数栖息地。长足蚁主要出现在灌丛林地，这与其在其他地方对雨林的偏好形成对比。对整体蚂蚁物种组成的多变量分析表明，根据外来物种的分布，各地点存在强烈分化，且这些模式在属和功能组水平上也得以保持。在栖息地变量无差异的情况下，入侵和未入侵的雨林地点的本地蚂蚁组成有所不同。广义蚁亚科和森林机会主义者受入侵影响尤为严重。长足捷蚁的丰富度与本地蚂蚁的丰富度和物种丰富度之间存在强烈的负相关关系。这强调了，除了在数量上主导许多蚂蚁群落外，一些外来物种，特别是长足捷蚁，对本地蚂蚁群落有显著影响。
