Vegetation influences desert soil arthropods and their response to altered precipitation

Altered size and frequency of precipitation pulses will influence both plant and soil communities in water-limited systems such as the Sonoran Desert. Little is known about the response of desert soil fauna communities, particularly the mesofauna that are important components of the detrital food web. Further, while there is a well-documented impact of vegetation on soil fauna communities, the role of vegetation in buffering the soil community against such environmental changes is unclear. We conducted a short-term field study to (1) assess how the amount and frequency of monsoon season precipitation pulses influence soil arthropod communities and (2) explore the role of plant-soil linkages in the response of soil arthropod communities to altered precipitation. We experimentally altered the size (ambient and 50% increase) and frequency (ambient and 2X reduced frequency) of monsoon season precipitation for two dominant shrubs representing distinctly different functional types, as well as interplant spaces. We measured the resulting soil arthropod abundance, diversity, and composition, as well as key soil properties to characterize the soil habitat beneath each vegetation type.

降水脉冲的强度与频次发生改变后，将对索诺兰沙漠（Sonoran Desert）这类水分受限生态系统中的植物与土壤群落产生影响。目前学界对荒漠土壤动物群落的响应特征尚不明确，尤其是作为腐食食物网重要组成部分的中型土壤动物（mesofauna）。此外，尽管已有大量文献证实植被对土壤动物群落存在影响，但植被在缓冲土壤群落抵御此类环境变化中所发挥的作用仍不明晰。本研究开展了一项短期野外实验，旨在达成两个核心目标：其一，评估季风季降水脉冲的强度与频次如何影响土壤节肢动物（soil arthropod）群落；其二，探究植物-土壤联系在土壤节肢动物群落响应降水改变过程中所扮演的角色。我们针对两种功能型显著不同的优势灌木以及株间空地，对季风季降水的强度（设置自然对照与增加50%两个梯度）与频次（设置自然对照与降低50%两个梯度，即2倍减少频次）进行了人工调控。我们测定了由此产生的土壤节肢动物丰度、多样性与群落组成，同时测定了关键土壤理化性质，以表征各植被类型下的土壤生境特征。