Human activities drive ecological transformation, impacting island ecosystems from species diversity to ecological traits, mainly through habitat degradation and invasive species. Using two unique long-term datasets we aim to evaluate whether species traits (body size, trophic level, dispersal capacity and habitat occupancy) can predict temporal variations in the abundance of endemic, indigenous (endemic and native non-endemic) and exotic arthropods in the Azores Islands. We found that body size is crucial to predict arthropod abundance trends. Small-bodied herbivorous arthropods showed a decrease in abundance, while large-bodied indigenous arthropods increased in abundance, mainly in well-preserved areas. Also, large-bodied exotic arthropods increased in abundance across the entire archipelago. Moreover, endemic canopy dwellers increased in abundance, while endemic ground-dwellers decreased in abundance. Simultaneously, exotic arthropods showed the opposite result, increasing in abundance in the ground while decreasing in abundance in the canopy. Finally, habitat influenced both endemic and exotic spider abundance trends. Endemic spiders that occupy solely natural habitats experienced a decline in abundance, while exotic spiders in the same habitats increased in abundance. Our study underscores the significance of arthropod species traits in predicting abundance changes in island ecosystems over time, as well as the importance of monitoring species communities. Conservation efforts must extend beyond endangered species to protect non-threatened ones, given the increased extinction risk faced by even common species on islands. Monitoring and restoration programs are essential for preserving island ecosystems and safeguarding endemic arthropod populations.

中文翻译：

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节肢动物特征作为亚速尔群岛丰度趋势的代表


人类活动推动了生态转型，主要通过栖息地退化和入侵物种影响岛屿生态系统，从物种多样性到生态特征。使用两个独特的长期数据集，我们旨在评估物种特征（体型、营养水平、扩散能力和栖息地占用率）是否可以预测亚速尔群岛地方性、本地（地方性和本地非地方性）和外来节肢动物丰度的时间变化。我们发现体型对于预测节肢动物的丰度趋势至关重要。小体型草食性节肢动物的丰度有所下降，而大型本地节肢动物的丰度有所增加，主要在保存完好的地区。此外，整个群岛的大型外来节肢动物数量增加。此外，地方性树冠居民的丰度增加，而地方性地生居民的丰度下降。同时，外来节肢动物显示出相反的结果，在地面中的丰度增加，而在树冠中的丰度减少。最后，栖息地影响了地方性和外来蜘蛛的丰富趋势。仅占据自然栖息地的特有蜘蛛数量下降，而相同栖息地的外来蜘蛛数量增加。我们的研究强调了节肢动物物种特征在预测岛屿生态系统丰度随时间变化方面的重要性，以及监测物种群落的重要性。鉴于岛上的常见物种面临的灭绝风险增加，保护工作必须超越濒危物种，以保护非受威胁物种。监测和恢复计划对于保护岛屿生态系统和保护地方性节肢动物种群至关重要。