Species extinction has reached unprecedented rates globally, and can cause unexpected ecological cascades. Since Europeans arrived in Australia, many endemic mammals have declined or become extinct, but their ecological roles and outcomes of their reintroduction for ecosystems are poorly understood. Using surveys and novel long-term exclusion and disturbance experiments, we tested how digging mammal reintroduction affects predatory invertebrates. Mammal exclusion tended to decrease bare ground. Although scorpion burrow abundance increased with bare ground, mammals also had direct negative effects on scorpions. Increased disturbance alone decreased scorpion abundance, but other mechanisms, such as predation, also contributed to the mammal effect. Despite negative associations between scorpions and spiders, both groups increased and spider composition changed following mammal exclusion. Our long-term research showed that threatened digging mammals drive ecosystem cascades, affecting biota through a variety of pathways. Reintroductions of locally extinct digging mammals can restore ecosystems, but ecosystem cascades may lead to unexpected restructuring.

中文翻译：

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受威胁的哺乳动物重新引入后生态级联的实验证据

物种灭绝在全球范围内达到了前所未有的速度，并可能导致意想不到的生态级联反应。自从欧洲人抵达澳大利亚以来，许多地方性哺乳动物已经减少或灭绝，但它们的生态作用和重新引入生态系统的结果知之甚少。通过调查和新颖的长期排斥和干扰实验，我们测试了挖掘哺乳动物的重新引入如何影响捕食性无脊椎动物。哺乳动物排斥趋向于减少裸露地面。尽管蝎子洞穴的丰度随着裸地而增加，但哺乳动物也对蝎子产生了直接的负面影响。单独增加干扰会降低蝎子的丰度，但其他机制，如捕食，也有助于哺乳动物的影响。尽管蝎子和蜘蛛之间存在负面关联，排除哺乳动物后，两组均增加，蜘蛛组成发生变化。我们的长期研究表明，受威胁的挖掘哺乳动物推动生态系统级联，通过各种途径影响生物群。重新引入当地已灭绝的挖掘哺乳动物可以恢复生态系统，但生态系统级联可能会导致意想不到的重组。