Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen 6708PB, the Netherlands.
Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen 6708PB, the Netherlands; Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Sciencepark 904, Amsterdam 1098 XH, The Netherlands.
Water Res. 2023 May 15;235:119915. doi: 10.1016/j.watres.2023.119915. Epub 2023 Mar 26.
Land-water transition areas play a significant role in the functioning of aquatic ecosystems. However, anthropogenic pressures are posing severe threats on land-water transition areas, which leads to degradation of the ecological integrity of many lakes worldwide. Enhancing habitat complexity and heterogeneity by restoring land-water transition areas in lake systems is deemed a suitable method to restore lakes bottom-up by stimulating lower trophic levels. Stimulating productivity of lower trophic levels (phytoplankton, zooplankton) generates important food sources for declining higher trophic levels (fish, birds). Here, we study ecosystem restoration project Marker Wadden in Lake Markermeer, The Netherlands. This project involved the construction of a 700-ha archipelago of five islands in a degrading shallow lake, aiming to create additional sheltered land-water transition areas to stimulate food web development from its base by improving phytoplankton quantity and quality. We found that phytoplankton quantity (chlorophyll-a concentration) and quality (inversed carbon:nutrient ratio) in the shallow waters inside the Marker Wadden archipelago were significantly improved, likely due to higher nutrient availabilities, while light availability remained sufficient, compared to the surrounding lake. Higher phytoplankton quantity and quality was positively correlated with zooplankton biomass, which was higher inside the archipelago than in the surrounding lake due to improved trophic transfer efficiency between phytoplankton and zooplankton. We conclude that creating new land-water transition areas can be used to increase light and nutrient availabilities and thereby enhancing primary productivity, which in turn can stimulate higher trophic levels in degrading aquatic ecosystems.
水陆过渡区在水生生态系统的功能中起着重要作用。然而，人为压力正对水陆过渡区构成严重威胁，导致世界上许多湖泊的生态完整性退化。通过恢复湖泊系统的水陆过渡区来提高生境的复杂性和异质性，被认为是一种通过刺激较低营养级来自下而上恢复湖泊的合适方法。刺激较低营养级（浮游植物、浮游动物）的生产力为下降的较高营养级（鱼类、鸟类）产生了重要的食物来源。在这里，我们研究了荷兰马克尔梅勒湖的生态系统恢复项目 Marker Wadden。该项目涉及在一个退化的浅湖中建造一个 700 公顷的五岛群岛，旨在通过增加浮游植物的数量和质量来改善水质，从而创造更多的受保护的水陆过渡区，刺激食物网的发展。我们发现，Marker Wadden 群岛内部的浅水浮游植物数量（叶绿素-a 浓度）和质量（碳：营养比的倒数）有显著改善，这可能是由于营养物质的可用性增加，而与周围湖泊相比，光照仍然充足。较高的浮游植物数量和质量与浮游动物生物量呈正相关，由于浮游植物和浮游动物之间的营养转移效率提高，因此群岛内部的浮游动物生物量高于周围湖泊。我们的结论是，创造新的水陆过渡区可以用来增加光和营养物质的可用性，从而提高初级生产力，进而可以刺激退化水生生态系统中的较高营养级。
