Tanentzap Andrew J, Szkokan-Emilson Erik J, Kielstra Brian W, Arts Michael T, Yan Norman D, Gunn John M
1] Vale Living with Lakes Centre, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6 [2].
Vale Living with Lakes Centre, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6.
Nat Commun. 2014 Jun 11;5:4077. doi: 10.1038/ncomms5077.
Aquatic ecosystems are fuelled by biogeochemical inputs from surrounding lands and within-lake primary production. Disturbances that change these inputs may affect how aquatic ecosystems function and deliver services vital to humans. Here we test, using a forest cover gradient across eight separate catchments, whether disturbances that remove terrestrial biomass lower organic matter inputs into freshwater lakes, thereby reducing food web productivity. We focus on deltas formed at the stream-lake interface where terrestrial-derived particulate material is deposited. We find that organic matter export increases from more forested catchments, enhancing bacterial biomass. This transfers energy upwards through communities of heavier zooplankton, leading to a fourfold increase in weights of planktivorous young-of-the-year fish. At least 34% of fish biomass is supported by terrestrial primary production, increasing to 66% with greater forest cover. Habitat tracers confirm fish were closely associated with individual catchments, demonstrating that watershed protection and restoration increase biomass in critical life-stages of fish.
水生生态系统由来自周边陆地和湖泊内部初级生产的生物地球化学输入提供能量。改变这些输入的干扰可能会影响水生生态系统的功能以及提供对人类至关重要的服务的方式。在这里，我们利用跨越八个独立集水区的森林覆盖梯度进行测试，去除陆地生物量的干扰是否会降低进入淡水湖泊的有机物质输入，从而降低食物网生产力。我们关注在溪流 - 湖泊界面形成的三角洲，陆地来源的颗粒物质在那里沉积。我们发现，来自森林覆盖率更高的集水区的有机物质输出增加，增强了细菌生物量。这通过较重的浮游动物群落向上传递能量，导致当年幼体食浮游生物鱼类的体重增加了四倍。至少34%的鱼类生物量由陆地初级生产支持，随着森林覆盖率的提高，这一比例增加到66%。栖息地示踪剂证实鱼类与各个集水区密切相关，表明流域保护和恢复增加了鱼类关键生命阶段的生物量。
