Surviving drought: a framework for understanding animal responses to small rain events in the arid-zone

Large rain events drive dramatic resource pulses and the complex pulse-reserve dynamics of arid ecosystem changes between high-rain years and drought. However, arid-zone animal responses to short-term changes in climate are unknown, particularly smaller rain events that briefly interrupt longer-term drought. Using arthropods as model animals, we determined the effects of a small rain event on arthropod abundance in western NSW, Australia during a longer-term shift towards drought. Arthropod abundance decreased over two years, but captures of ten out of fifteen ordinal groups increased dramatically after the small rain event (<40mm). The magnitude of increases ranged from 10.4 million% (collembolans) to 81% (spiders). After three months, most groups returned to pre-rain abundance. However, small soil-dwelling beetles, mites, spiders, and collembolans retained high abundances despite the onset of winter temperatures and lack of subsequent rain. As predicted by pulse-reserve models, mos...

大量降雨事件驱动着干旱生态系统在多雨年份与干旱期之间发生剧烈的资源脉冲及复杂的脉冲-储备动态变化。然而，干旱区动物对气候短期变化的响应尚不清楚，尤其是那些短暂中断长期干旱的小型降雨事件。以节肢动物为模式动物，我们研究了澳大利亚新南威尔士州西部在向干旱长期转变期间，一次小型降雨事件对节肢动物丰度的影响。节肢动物丰度在两年间有所下降，但在此次小型降雨事件（<40毫米）后，15个目类群中有10个的捕获量显著增加。增幅范围从1040万%（弹尾目）到81%（蜘蛛目）不等。三个月后，大多数类群恢复到降雨前的丰度。然而，尽管冬季气温来临且后续无降雨，小型土壤栖息甲虫、螨类、蜘蛛和弹尾目仍保持较高丰度。正如脉冲-储备模型所预测的，mos...