Canopy connectivity and the availability of diverse nesting resources affect species coexistence in arboreal ants.
Canopy connectivity and the availability of diverse nesting resources affect species coexistence in arboreal ants.
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树冠连通性和多样化筑巢资源的可用性影响树栖蚂蚁的物种共存。
DOI：
10.1111/j.1365-2656.2010.01779.x
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
H. Vasconcelos
中科院分区：
文献类型：
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作者：
S. Powell;A. N. Costa;C. T. Lopes;H. Vasconcelos
1. 树栖蚂蚁种类繁多，在热带地区具有生态优势。这些具有生态重要性的群体可能在持续的实证研究中特别有用，以了解调节物种多样性和共存的过程。 2. 我们的研究探讨了树木资源的获取和预先存在的巢穴的多样性如何影响热带树栖蚂蚁群落的物种多样性和共存。我们专注于局部尺度上这些变量的组合级响应。我们首先调查了三个自然发生的树冠连通性水平和树木大小梯度的树栖蚂蚁多样性。然后，我们对树冠连通性和空腔入口尺寸的多样性进行了全树实验操作。所有工作均在巴西稀树草原或“塞拉多”进行。 3. 我们的调查表明，物种丰富度在连通性水平之间是相当的。然而，物种密度较低且冠层连通性较低的趋势是一致的。这在单棵树的规模上得到了证实，连通性低的树在所有树尺寸上的物种都明显较少。我们的实验直接证明，低树冠连通性会导致每棵树共存的物种显着减少。 4. 不同的空腔入口尺寸并没有显着增加每棵树的总体物种数。尽管如此，空洞多样性确实显着增加了每棵树上使用新空洞的物种、每棵树新空洞特有的物种、使用新空洞的物种总数以及空洞的总使用量。被占据的空洞的数量与新建立的蚁群和其他树上已建立的蚁群的新巢相一致。因此，空腔多样性似乎极大地影响了新群体的建立和群体的生长。 5. 这些结果提供了强有力的证据，表明更多的资源获取和更大的洞穴多样性对当地树栖蚂蚁群落中的物种共存具有积极影响。更一般地说，这些积极影响与促进本地物种在不同树栖蚂蚁群落中共存的生态位分化大致一致。讨论了这项研究对理解物种共存过程的贡献，以及焦点系统在这一问题上未来工作的潜力。
1. Arboreal ants are both diverse and ecologically dominant in the tropics. Such ecologically important groups are likely to be particularly useful in ongoing empirical efforts to understand the processes that regulate species diversity and coexistence. 2. Our study addresses how access to tree-based resources and the diversity of pre-existing nesting cavities affect species diversity and coexistence in tropical arboreal ant assemblages. We focus on assemblage-level responses to these variables at local scales. We first surveyed arboreal ant diversity across three naturally occurring levels of canopy connectivity and a gradient of tree size. We then conducted whole-tree experimental manipulations of canopy connectivity and the diversity of cavity entrance sizes. All work was conducted in the Brazilian savanna or 'cerrado'. 3. Our survey suggested that species richness was equivalent among levels of connectivity. However, there was a consistent trend of lower species density with low canopy connectivity. This was confirmed at the scale of individual trees, with low-connectivity trees having significantly fewer species across all tree sizes. Our experiment demonstrated directly that low canopy connectivity results in significantly fewer species coexisting per tree. 4. A diverse array of cavity entrance sizes did not significantly increase overall species per tree. Nevertheless, cavity diversity did significantly increase the species using new cavities on each tree, the species per tree unique to new cavities, total species using new cavities, and total cavity use. The populations of occupied cavities were consistent with newly founded colonies and new nests of established colonies from other trees. Cavity diversity thus appears to greatly affect new colony founding and colony growth. 5. These results contribute strong evidence that greater resource access and greater cavity diversity have positive effects on species coexistence in local arboreal ant assemblages. More generally, these positive effects are broadly consistent with niche differentiation promoting local species coexistence in diverse arboreal ant assemblages. The contributions of this study to the understanding of the processes of species coexistence are discussed, along with the potential of the focal system for future work on this issue.