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

尘埃在地球表面的移动是一个为生态系统带来营养的重要过程。这一过程对通常营养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接收沙尘，但由于极低的背景沉降率，很难计算营养物的数量和沙尘的总体影响。2020年6月，北非沙漠产生了一场大型沙尘暴，并穿越大西洋进入加勒比海。据估计，这次沙尘暴是近五十年来最大的一次。这一事件为研究沙尘对热带生态系统的影响提供了机会。该项目将量化沙尘输入、它们对土壤和水质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提供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。将产生多份同行评议的手稿，描述这一极端事件及其对热带生态系统的生态意义。来自北非萨赫勒和撒哈拉沙漠的沙尘每年为加勒比地区的热带森林提供钙、镁和磷的可靠来源。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。在高度风化的景观中，这种影响可能对营养有限的生物过程产生重大影响。为了研究这些影响，将在波多黎各的Luquillo山脉流域频繁地（每周）取样土壤水、水井和溪流。一个水质传感器网络已经到位，将每15分钟记录一次水质，以及通过溶解氧变化记录河流初级生产力和呼吸的生物特征。这些数据将用于检验大量灰尘输入改变流域尺度生物地球化学循环的假设。为了了解流域尺度的响应，将这些粉尘输入与土壤溶液和地下水化学联系起来，然后将其输出到水系网络，并评估水系生态系统的生物响应。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.