Collaborative Research: Exploring the geography of sodium as a catalyst in terrestrial communities and ecosystems

合作研究：探索钠作为陆地群落和生态系统催化剂的地理分布

• 批准号: 1556280
• 负责人: Michael Kaspari
• 金额: $ 53.12万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1556280&HistoricalAwards=false
• 关键词: Collaborative; Research; Exploring; geography; sodium

Essential services performed by Earth's ecosystems, such as decomposing detritus into nutrients, transforming plants into meat, creating and aerating fertile soil, arise from the combined actions of millions of organisms. Each of these organisms, from bacteria to butterflies to bison, best contribute to these services when they consume a healthy diet, which includes access to minerals, especially sodium. Sodium is a critical mineral for ecosystems because plants are generally low in sodium but the things that eat them, from fungi to grasshoppers, require it to grow and reproduce. Thus every plant eater must search out, harvest, and hang onto quantities of sodium, and will go to extremes eating carcasses, soil, and urine, to get that quota. Moreover, sodium is not uniformly distributed on the landscape. It falls as dilute ocean water near the coasts, it clings to clay soils but is leached from sandy soils, and it is distributed by the truckload to keep snowy roads free from ice. This project combines these two facts, that sodium is potentially one of the most important drivers of the health of plant consumers, and that sodium is geographically patchy, to predict the abundance and services of plant consumers across the North American continent. This research should lead to better prediction of such disparate phenomena as why grasshoppers are bigger crop pests in one county than another; why carbon is better stored in inland soils than those near the ocean; and why termite damage claims are centered along the Gulf Coast of the U.S. and up into the Mid-Atlantic states.To evaluate this proposition, the project combines two methods. The first maps the distribution of sodium across and within North American ecosystems and focuses on the easily accessible and widespread grasslands, old fields, and roadsides, and the invertebrates that live in them. The goal in Year 1 is to explore the basic hypothesis that as soil supplies of sodium increase - due to deposition from the ocean, high clay content, or because they are salted every winter - plants will not be affected but the animals that eat them (and the predators that eat the plant consumers) will. Thus the first year will generate a map of the abundance and activity of invertebrates above and belowground, and the degree to which both track sodium supply (and other nutrients). Then, in Year 2 and 3, these correlations will be put to the test experimentally in 6 grasslands from the central and eastern U.S. At each grassland, 50 meter square plots will be fertilized with a dilute sodium concentrations mimicking the slightly salty rainfall of the island of Puerto Rico; smaller plots will receive sodium mimicking that deposited on a regular basis by every animal as urine. By carefully tracking where the sodium goes, and how it boosts the numbers and activity of invertebrates, the project will test how animal health and vigor across North America is influenced by sodium supply. By examining how pollinators, herbivores, and detritivores respond, the project will test the transformative idea that sodium is a catalyst for ecosystem services.

地球生态系统所提供的基本服务，例如将碎屑分解为营养物质、将植物转化为肉类、创造肥沃的土壤并使其通气，这些服务是由数百万个生物体的共同作用产生的。这些生物体，从细菌到蝴蝶再到野牛，只有在摄入健康饮食（包括获取矿物质，尤其是钠）时才能最好地为这些服务做出贡献。钠是生态系统的重要矿物质，因为植物的钠含量通常较低，但以它们为食的生物（从真菌到蚱蜢）却需要钠来生长和繁殖。 因此，每个植物食者都必须寻找、收获和保存一定数量的钠，并且会极端地吃尸体、土壤和尿液，以获得这个配额。此外，钠在景观中的分布并不均匀。 它以稀释的海水形式落在海岸附近，附着在粘土上，但从沙土中滤出，并按卡车进行分配，以保持积雪的道路不结冰。该项目结合了这两个事实，即钠可能是植物消费者健康最重要的驱动因素之一，并且钠在地理上不均匀，以预测整个北美大陆植物消费者的丰度和服务。这项研究应该能够更好地预测诸如为什么蚱蜢在一个县比另一个县是更大的农作物害虫等不同现象；为什么内陆土壤比海洋附近的土壤更能储存碳？以及为什么白蚁损害索赔集中在美国墨西哥湾沿岸和大西洋中部各州。为了评估这一主张，该项目结合了两种方法。第一个地图描绘了北美生态系统中的钠分布，重点关注容易到达且分布广泛的草原、旧田地和路边，以及生活在其中的无脊椎动物。第一年的目标是探索一个基本假设，即随着土壤钠供应的增加（由于海洋沉积、高粘土含量或每年冬天盐分增加），植物不会受到影响，但吃它们的动物（以及吃植物消费者的捕食者）会受到影响。因此，第一年将生成一张地图，显示地上和地下无脊椎动物的丰度和活动，以及两者追踪钠供应（和其他营养物质）的程度。然后，在第二年和第三年，这些相关性将在美国中部和东部的 6 个草原上进行实验测试。在每个草原上，50 平方米的土地上将使用模拟波多黎各岛微咸降雨的稀钠浓度施肥；较小的地块将接受每只动物定期以尿液形式沉积的钠模拟物。通过仔细追踪钠的去向，以及它如何促进无脊椎动物的数量和活动，该项目将测试钠供应如何影响北美动物的健康和活力。通过研究传粉动物、食草动物和食腐动物的反应，该项目将测试钠是生态系统服务催化剂的变革性想法。