Diet breadth, coexistence and rarity in bumblebees
Diet breadth, coexistence and rarity in bumblebees
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DOI：
10.1007/s10531-008-9428-y
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发表时间：
2008-12-01
影响因子：
3.4
通讯作者：
Darvill, Ben
中科院分区：
文献类型：
--
作者：
Goulson, Dave;Lye, Gillian C.;Darvill, Ben
决定大黄蜂物种相对丰度的因素仍然知之甚少，这使得对稀有和衰退物种的管理变得困难。对美洲大黄蜂群落的研究表明，舌头长度相似的物种之间存在着强烈的竞争相互作用，这种竞争决定了物种的相对丰度。相比之下，在欧洲，通常观察到几个短舌物种共存，很少或根本没有证据表明竞争形成了群落结构。在这项研究中，我们研究了欧洲最多样化的大黄蜂群落之一的丰度和分布模式，该群落位于波兰南部的山区。我们量化了23种大黄蜂采集花蜜和花粉时的饲料使用情况，并研究了共生和生态位重叠的模式，以确定是否存在种间竞争的证据。我们还测试了稀有性是否可以用饮食宽度来解释。单样地共存在16种，物种丰富度在海拔1000 m左右的山地牧场最高。研究结果与以往的研究结果一致，表明大黄蜂采集的大部分花粉来自豆科，但一些蜜蜂物种（如B. ruderatus）比其他蜜蜂物种（如B. lucorum）更依赖于豆科。那些主要以豆科植物为食的物种往往有长长的舌头。与英国的研究一样，饮食广度与丰度相关：在校正样本大小的差异后，稀有物种倾向于访问较少的花卉物种。没有证据表明舌头长度的相似性或饮食重叠会影响物种共生的可能性。然而，最丰富的物种（在大多数地点共同出现）占据了不同的饮食生态位空间。虽然舌头长度相似的物种总体上倾向于有更高的饮食生态位重叠，但在大量共同出现的短舌物种中，存在明显的饮食差异，这可能解释了它们共存的原因。
Factors that determine the relative abundance of bumblebee species remain poorly understood, rendering management of rare and declining species difficult. Studies of bumblebee communities in the Americas suggest that there are strong competitive interactions between species with similar length tongues, and that this competition determines the relative abundance of species. In contrast, in Europe it is common to observe several short-tongued species coexisting with little or no evidence for competition shaping community structure. In this study we examine patterns of abundance and distribution in one of the most diverse bumblebee communities in Europe, found in the mountains of southern Poland. We quantify forage use when collecting nectar and pollen for 23 bumblebee species, and examine patterns of co-occurrence and niche overlap to determine whether there is evidence for inter-specific competition. We also test whether rarity can be explained by diet breadth. Up to 16 species were found coexisting within single sites, with species richness peaking in mountain pasture at similar to 1,000 m altitude. Results concur with previous studies indicating that the majority of pollen collected by bumblebees is from Fabaceae, but that some bee species (e.g. B. ruderatus) are much more heavily dependent on Fabaceae than others (e.g. B. lucorum). Those species that forage primarily on Fabaceae tended to have long tongues. In common with studies in the UK, diet breadth was correlated with abundance: rarer species tended to visit fewer flower species, after correcting for differences in sample size. No evidence was found for similarity in tongue length or dietary overlap influencing the likelihood of co-occurrence of species. However, the most abundant species (which co-occurred at most sites) occupied distinct dietary niche space. While species with tongues of similar length tended, overall, to have higher dietary niche overlap, among the group of abundant short-tongued species that commonly co-occurred there was marked dietary differentiation which may explain their coexistence.