PRF/J: Trophic Interactions Within a Wetland Food Web That Influence Populations of Midge Detritivores

由于最近对湖泊和河流的研究表明，营养相互作用强烈地影响着群落结构，因此可以预期，这种相互作用也将同样影响湿地群落。然而，尽管在大多数湖泊和河流研究中考察的初级生产者是活的植物，但湿地中大多数消耗性初级生产力是碎屑。因此，湿地中的食物网动态可能与其他水生系统中的不同。以前的湿地研究人员已经操纵了碎屑生物量的自下而上的力量，但有害生物种群往往不会做出反应；湿地有害动物可能不受资源限制。很少有研究研究湿地有害食肉动物如何受到自上而下的捕食力量的影响。研究自下而上与碎屑的相互作用以及与捕食者的自上而下的相互作用如何同时影响有害的食虫种群的实验是有计划的。利用纽约湿地的围栏/围栏中隔(2x2m)，将研究以下现象：对植物凋落物生物量的驱蚊反应、一级捕食者密度(昆虫)和二级捕食者密度(鱼)。将确定碎屑对蚊子食物和栖息地异质性的相对影响。湿地栖息地可以说是所有水生栖息地中最不被了解的，也是最濒危的。如今，有关湿地的政策决策是在科学信息不足的情况下做出的。除了解决有关湿地的理论问题外，这项工作还对应用生态学有影响，因为蚊子是初级生产者和更高层次的消费者(如雀形目鸟类和水禽)之间的重要纽带。

Because recent studies in lakes and rivers indicate that trophic interactions strongly influence community structure, it might be expected that such interactions would similarly influence wetland communities. However while the primary producers examined in most lake and river studies were live plants, most consumable primary production in wetlands is detritus. Thus food web dynamics in wetlands probably differ from those in other aquatic systems. Previous wetland researchers have manipulated the bottom-up force of detritus biomass but detritivore populations often don't respond; wetland detritivores may not be resource limited. Few investigations have examined how wetland detritivores are influenced by top-down forces of predation. Experiments that examine how bottom-up interactions with detritus and top-down interactions with predators concurrently affect populations of detritivorous midges are planned. Using enclosure/exclosure mesocosms (2 x 2 m) in a New York wetland, the following phenomena will be examined: midge responses to plant litter biomass, first- level predator densities (insects), and second-level predator densities (fish). The relative influences on midges of food and habitat heterogeneity from detritus will be determined. %%% Wetland habitats are arguably the least understood of all aquatic habitats and are the most endangered as well. These days, policy decisions regarding wetlands are being made with insufficient scientific information. In addition to addressing theoretical questions about wetlands, this work has implications for applied ecology because midges are important links between primary producers and higher level consumers (such as passerine birds and waterfowl).