Latitudinal gradient in species diversity provides high niche opportunities for a range‐expanding phytophagous insect
Latitudinal gradient in species diversity provides high niche opportunities for a range‐expanding phytophagous insect
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物种多样性的纬度梯度为范围扩大的植食性昆虫提供了高生态位机会
DOI：
10.1111/1365-2656.13780
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发表时间：
2022
影响因子：
4.8
通讯作者：
Prior, Kirsten M.
中科院分区：
文献类型：
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作者：
Jones, Dylan G.;Kobelt, Julia;Ross, Jenna M.;Powell, Thomas H.;Prior, Kirsten M.
当物种为了应对人为的变化而向极地扩展时，它们可能会在新的地点遇到多样性较低的群落。如果低多样性群落提供弱的生物相互作用，例如减少竞争或捕食，则范围扩大的物种可能会经历高生态位机会。在这里，我们调查了橡树瘿蜂群落是否遵循纬度多样性梯度（LDG），以及低多样性群落是否为范围扩大的群落成员Neuroterus saltatorius提供较弱的两极相互作用。我们对优势橡树上的瘿蜂进行了系统调查，分布于北方加州至温哥华岛、不列颠哥伦比亚省的大部分地区。在18个站点的540棵树上，我们确定了23个橡树瘿蜂形态类型在三个公会（叶可拆卸，叶积分，茎瘿）。我们对橡树瘿蜂多样性、纬度以及其他非生物（例如温度）和栖息地（例如橡树斑块大小）因素进行了回归，以揭示瘿蜂群落是否遵循LDG。为了揭示局部相互作用的模式，我们首先在区域内的树木上进行了瘿蜂形态型发生的部分相关性。然后，我们对树上共存的瘿蜂的丰度进行了回归，以揭示相互作用是竞争性的还是拮抗性的。garryana-gall蜂群落遵循LDG，在高纬度地区多样性较低，特别是可分离的叶瘿形态类型的损失。可分离的叶瘿蜂，包括范围扩大的物种，共同发生在树木上的最多，与弱共同发生在树木的北方扩展区域。N. saltatorius和可分离和完整的叶瘿共同发生在树上呈负相关，表明拮抗作用。总的来说，我们发现LDG在两极创造了具有较弱关联的群落，这可能有助于范围扩大的群落成员的生态释放。鉴于LDG在自然界中的普遍存在，向极扩展的物种可能会进入低多样性群落。然而，了解纬度多样性模式是否为范围扩大的物种提供了弱的生物相互作用还没有得到很好的探索。我们的大规模研究记录了在宿主植物上共同出现的植食性昆虫相关群落的多样性，揭示了LDG为范围扩大的群落成员创造了高生态位机会。多样性和物种相互作用的生物地理模式可能是导致范围扩展下生物相互作用改变的重要机制。
When species undergo poleward range expansions in response to anthropogenic change, they likely encounter less diverse communities in new locations. If low diversity communities provide weak biotic interactions, such as reduced competition or predation, range‐expanding species may experience high niche opportunities.Here, we investigated if oak gall wasp communities follow a latitudinal diversity gradient (LDG) and if lower diversity communities provide weaker interactions at the poles for a range‐expanding community member,Neuroterus saltatorius.We performed systematic surveys of gall wasps on a dominant oak,Quercus garryana, throughout most of its range, from northern California to Vancouver Island, British Columbia. On 540 trees at 18 sites, we identified 23 oak gall wasp morphotypes in three guilds (leaf detachable, leaf integral, and stem galls). We performed regressions between oak gall wasp diversity, latitude, and other abiotic (e.g. temperature) and habitat (e.g. oak patch size) factors to reveal if gall wasp communities followed an LDG. To uncover patterns in local interactions, we first performed partial correlations of gall wasp morphotype occurrences on trees within regions). We then performed regressions between abundances of co‐occurring gall wasps on trees to reveal if interactions are putatively competitive or antagonistic.Q. garryana‐gall wasp communities followed an LDG, with lower diversity at higher latitudes, particularly with a loss of detachable leaf gall morphotypes. Detachable leaf gall wasps, including the range‐expanding species, co‐occurred most on trees, with weak co‐occurrences on trees in the northern expanded region. Abundances ofN. saltatoriusand detachable and integral leaf galls co‐occurring on trees were negatively related, suggesting antagonistic interactions. Overall, we found that LDGs create communities with weaker associations at the poles that might facilitate ecological release in a range‐expanding community member.Given the ubiquity of LDGs in nature, poleward range‐expanding species are likely moving into low diversity communities. Yet, understanding if latitudinal diversity pattern provides weak biotic interactions for range‐expanding species is not well explored. Our large‐scale study documenting diversity in a related community of phytophagous insects that co‐occur on a host plant reveals that LDGs create high niche opportunities for a range‐expanding community member. Biogeographical patterns in diversity and species interactions are likely important mechanisms contributing to altered biotic interactions under range‐expansions.