Can isolated wetlands come to the trophic rescue of surrounding ecosystems? Investigating new pathways for food web connectivity

孤立的湿地能否对周围生态系统进行营养拯救？

• 批准号: RGPIN-2018-04291
• 负责人: Jardine, Timothy
• 金额: $ 2.4万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654523
• 关键词: isolated; wetlands; come; trophic; rescue

Food web subsidies occur when a productive “donor” habitat sends nutrients, energy and/or organic matter to an unproductive “recipient” habitat. This movement of materials can stabilize food webs and enable higher overall productivity, but can also deliver contaminants. These fluxes are challenging to study and to manage because they are at odds with conventional notions of ecosystem boundaries. ******There are more than 20 million small wetlands across the globe, and many of these are deemed inconsequential by humans because they are shallow, isolated from surrounding waterbodies, freeze or dry out entirely in the winter, and lack fish. As such, they are regularly viewed as simple sinks for waste, leaving them undervalued by society and often drained, filled or degraded. This research program challenges that notion, and instead examines them as important donor habitats, providing a significant foodweb subsidy via a large flux of winged organisms – namely semi-aquatic (waterboatmen) and emergent (midges) insects. It is possible that this subsidy is responsible for maintaining fisheries production in rivers and lakes both in this region and in other cold or dry regions of the world, but little is known about its quality, including both healthy (omega-3 fatty acids) and harmful (mercury) compounds.******This program will test if these wetlands come to the trophic rescue of rivers, lakes and fields by evaluating the timing, magnitude, and nutritional quality of the subsidy. My team will examine how these fluxes change in different parts of North America, from northern Canadian environments where ice-cover is significant and the summer growing season is short, to arid environments in the southern United States where most wetlands dry completely in late summer. We will also determine if these insects deliver contaminants such as mercury from wetlands to rivers, because wetlands are known hotspots for mercury methylation. Finally, we will evaluate how changes in water quality affect insect community composition and whether wetland degradation from eutrophication and salinization favors migrant or non-migrant taxa. Together, this research could reveal new reasons to conserve wetlands in Canada and across the globe.

当产品“捐赠者”栖息地将营养，能量和/或有机物发送给非生产性的“接受者”栖息地时，就会发生食物网络补贴。这种材料的运动可以稳定食物网，并使整体生产力更高，但也可以提供污染物。这些通量挑战研究和管理，因为它们与传统的生态系统边界概念不一致。 *****全球有超过2000万个小湿地，其中许多人被人类视为无关紧要，因为它们很浅，与周围的水体隔离，在冬季完全冷冻或完全干燥，并且缺乏鱼。因此，它们经常被视为浪费的简单水槽，使它们被社会低估，并经常被淹没，充满或退化。该研究计划挑战了概念，而是将其视为重要的供体栖息地，通过大量有翼生物的助焊剂（即半乳头（Waterboaten）和新兴的（Midges）绝缘提供了重要的食物韦布（Foodweb）补贴。这种补贴可能负责维持该地区以及世界其他寒冷或干燥地区的河流和湖泊的生产，但对其质量包括健康（Omega-3脂肪酸）和有害（汞）化合物的质量知之甚少。补贴的质量。我的团队将研究北美不同地区的这些通量如何变化，从北加拿大环境覆盖很大，夏季生长季节很短，到美国南部的干旱环境，那里大多数湿地在夏末都完全干燥。我们还将确定这些昆虫是否传递污染物，例如从湿地到河流的汞，因为湿地是汞甲基化的热点。最后，我们将评估水质的变化如何影响昆虫群落的组成，以及从富营养化和盐水中湿地降解是否有利于移民或非移民分类单元。这项研究共同揭示了在加拿大和全球保护湿地的新理由。