The role of petrichor – the scent of rain – in desert ecosystems and consequences under global warming

petrichor——雨的气味——在沙漠生态系统中的作用以及全球变暖带来的后果

• 批准号: 516726624
• 负责人: Professor Dr. Michael Bonkowski
• 金额: --
• 依托单位: Zuckerberg Institute for Water Research
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/516726624?language=en
• 关键词: role; petrichor; scent; rain; desert

In desert ecosystems, temporal dynamics are separated by wet-dry cycles, which are increasingly disturbed by Climate Change. Rainfall in desert ecosystems initiates an immediate CO2-burst together with substantial emissions of petrichor, 'the smell of rain'. This earthy smell is composed of various volatile organic compounds (VOCs), which travel with the wind for considerable distances. The water droplets in contact with dry soils elicit the release of previously sorbed VOCs and induce bacteria and fungi to produce VOCs de novo. Sixty years after the first description of petrichor, still little is known about its role in soil ecology and its relevance to atmospheric chemistry.Biotic interactions among members of soil microbial communities occur by exchanging signal molecules. Volatile signals act at greater spatial scale than soluble compounds and are increasingly recognized as crucial infochemicals to mediate intra- and interspecific interactions among soil microbiota. Yet, little is known on the specific functions of VOCs and their roles in mediating organism interactions, particularly in drylands.Emissions of petrichor from arid regions such as the Negev Desert (Israel) are likely to change in the near future as precipitation is projected to change by ~40% by 2050. Biogenic VOCs – particularly terpenoids and benzenoids – are essential players in atmospheric chemistry, influencing climate through cloud formation and the genesis of secondary organic aerosols, which absorb and scatter radiant energy. Soil microbial communities dominate desert ecosystems that span over 20% of the earth's surface. Therefore, there is an urgent need to consider the role of desert soil microbial communities in atmospheric chemistry. Our aim is to understand the sources, regulatory mechanisms, and controlling factors of VOC emissions in desert ecosystems which are paramount for building comprehensive global climate projection models. To this end, we aim to quantify and characterize changes in the petrichor composition along an aridity gradient in the Negev Desert (Israel), identify the entire activated microbial community (Eukaryota, Prokaryota, Archaea) after rain events in the desert biocrusts and in deeper soil layers, identify candidate producer and responsive taxa to VOCs by network analysis, and verify the roles of VOCs by targeted experiments with microbial isolates and by applying inhibitors of main petrichor VOCs to soils. Finally, we aim to upscale the global implications of petrichor emissions from desert ecosystems under future precipitation regimes.

在沙漠生态系统中，时间动态被干湿循环所分隔，而干湿循环越来越受到气候变化的干扰。沙漠生态系统中的降雨引发了立即的二氧化碳爆发，并伴随着大量的石油醚（petrichor）排放，即“雨的味道”。这种泥土味是由各种挥发性有机化合物（VOC）组成的，它们随风传播相当长的距离。与干燥土壤接触的水滴引起先前吸附的VOC的释放，并诱导细菌和真菌重新产生VOC。在首次描述petrichor 60年后，人们对其在土壤生态学中的作用及其与大气化学的相关性仍然知之甚少。土壤微生物群落成员之间的生物相互作用通过交换信号分子发生。挥发性信号比可溶性化合物在更大的空间尺度上起作用，并且越来越多地被认为是介导土壤微生物群种内和种间相互作用的关键信息化学物质。然而，对挥发性有机化合物的具体功能及其在介导生物体相互作用中的作用知之甚少，特别是在干旱地区，如内盖夫沙漠（以色列）的石油醚排放量可能会在不久的将来发生变化，预计到2050年降水量将变化约40%。生物挥发性有机化合物--特别是萜类化合物和苯并呋喃--是大气化学的重要参与者，通过云的形成和吸收和散射辐射能的二次有机气溶胶的形成来影响气候。土壤微生物群落在占地球表面20%以上的沙漠生态系统中占主导地位。因此，迫切需要考虑沙漠土壤微生物群落在大气化学中的作用。我们的目标是了解沙漠生态系统中VOC排放的来源，调节机制和控制因素，这对于建立全面的全球气候预测模型至关重要。为此，我们的目标是量化和表征内盖夫沙漠（以色列）的petrichor组成沿着干旱梯度的变化，确定整个活化的微生物群落（真核生物门，原核生物门，古生植物门）降雨事件后，在沙漠生物壳和更深的土壤层，确定候选生产者和响应分类群的挥发性有机化合物的网络分析，并通过微生物分离物的靶向实验和主要石油醚类挥发性有机物的抑制剂在土壤中的应用验证了挥发性有机物的作用。最后，我们的目标是扩大全球影响的petrichor排放沙漠生态系统在未来的降水制度。