Pred-Ex: Long Term Salt Marsh Predator Exclusion Experiment Conducted at Sapelo Island, GA

In southeastern USA salt marshes, short-term and small-scale experiments indicate that a trophic cascade benefits the foundation plant Spartina alterniflora: marine predators (nekton) positively affect plant biomass by consuming snail and crab herbivores. To test how nekton affect marsh processes when the entire animal community is present, and to test how prior results scale up over time, we conducted a 3-year predator exclusion experiment in a Georgia salt marsh using replicated 19.6 m2 plots. We measured the response of changing density for all marsh invertebrates, conducted snail and crab tethering trials, quantified change in marsh grass biomass, and measured tea bag decomposition rate across all plots.

在美国东南部的盐沼中，短期小规模实验表明，营养级联效应有利于基础植物互花米草（Spartina alterniflora）：海洋捕食者（游泳生物，nekton）通过捕食蜗牛和螃蟹等草食动物，对植物生物量产生积极影响。为验证当整个动物群落存在时游泳生物如何影响盐沼过程，并检验先前结果如何随时间扩大尺度，我们在佐治亚州盐沼中采用重复的19.6平方米样方，开展了为期3年的捕食者排除实验。我们测定了所有盐沼无脊椎动物的密度变化响应，进行了蜗牛和螃蟹的系留试验，量化了盐沼草生物量的变化，并在所有样方中测量了茶包分解率。