RAPID: Impacts of a massive dust storm on a tropical forest

尘埃在地球表面的移动是给生态系统带来养分的重要过程。这一过程对于营养往往极其有限的热带生态系统尤其重要。虽然北半球的热带森林每年从萨赫勒和撒哈拉沙漠收到沙尘输入，但由于背景沉降率很低，很难计算营养物质的数量和沙尘的整体影响。2020年6月，北非沙漠产生了一场大沙尘暴，它横跨大西洋进入加勒比海。据估计，这次沙尘暴是近50年来最大的一次。这次活动为研究沙尘对热带生态系统的影响提供了机会。该项目将量化灰尘输入，它们对土壤和水质量的影响，以及它们对热带森林的影响。该项目还将为代表性不足的学生开发一套教育和培训机会。将通过向公众提供数据来广泛传播结果。来自北非萨赫勒和撒哈拉的灰尘为加勒比海的热带森林提供了每年可靠的钙、镁和磷来源。这种尘埃通常是少量沉积的，但在2020年6月，波多黎各经历了一场大规模的沙尘暴。这种影响很可能对生物过程产生重大影响，在高度风化的地貌中，这些过程可能会受到营养物质的限制。为了研究这些影响，波多黎各卢基洛山脉的流域将高频(每周)对土壤水、水井和溪流进行采样。水质传感器网络已经到位，将每15分钟记录一次水质，以及通过溶解氧的变化记录河流初级生产力和呼吸的生物特征。这些数据将被用来检验这样一种假设，即大量的尘埃输入改变了分水岭尺度的生物地球化学循环。为了了解流域规模的响应，这些灰尘输入将在随后输出到河流网络后与土壤溶液和地下水化学相联系，并将对河流生态系统的生物响应进行评估。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The movement of dust across the surface of the Earth is an important process that brings nutrients to ecosystems. This process is especially important for tropical ecosystems that are often extremely nutrient limited. While tropical forests in the Northern Hemisphere receive dust inputs annually from the Sahel and Sahara deserts, it is difficult to calculate the quantity of nutrients and the overall effect of the dust because of very low background rates of deposition. A major dust storm was generated in June 2020 from the deserts of North Africa that was transported across the Atlantic Ocean and into the Caribbean. The specific dust storm was estimated to be the biggest in the last fifty years. This event provides an opportunity to study the impacts of dust on tropical ecosystems. The project will quantify the dust inputs, their effect on soil and water quality, and their impacts on a tropical forest. The project will also develop a set of education and training opportunities for under-represented students. Broad dissemination of results will occur through making data available to the public. Multiple peer-reviewed manuscripts will be produced that describe this extreme event and its ecological significance for tropical ecosystems.Dust from the Sahel and Sahara of North Africa provides an annual and reliable source of calcium, magnesium, and phosphorous to tropical forests in the Caribbean. This dust is usually deposited in small quantities, but in June 2020 Puerto Rico experienced a large magnitude dust storm. The effects are likely to be significant for biological processes that can be nutrient-limited in highly weathered landscapes. To study these effects, sampling of soil water, wells, and streams will occur at high frequency (weekly) in watersheds of the Luquillo Mountains of Puerto Rico. A network of water quality sensors is already in place and will record water quality every 15 minutes, as well as the biotic signatures of stream primary productivity and respiration through changes in dissolved oxygen. These data will be used to test the hypothesis that massive dust inputs alter watershed-scale biogeochemical cycles. To understand the watershed-scale response, these dust inputs will be connected to soil solution and groundwater chemistry, following their subsequent export to the stream network, and the biotic response of the stream ecosystem will be assessed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.