Data for Litoria ewingii tadpole experiments, Canterbury, New Zealand

Four experiments total were conducted, two in pond mesocosms and two in laboratory. The pond mesocosms experiments were to determine if <em>Litoria ewingii</em> tadpoles, non-native to New Zealand, affected any aspects of pond ecosystems. <br> The first experiment crossed predatory invertebrate presence with tadpole presence in a factorial anova design, and had many response variables: dissolved oxygen, benthic algae, plant mass, invertebrate abundances of many species, terrestrial leaf breakdown, number of tadpoles remaining, and FPOM or CPOM amount. <br> The second experiment had each tank shaded or unshaded, crossed with a gradient of tadpole densities, and measured phytoplankton, plant mass, dissolved oxygen, pH, and conductivity. <br> The third experiment measured ammonia-N excreted by tadpoles of varying lengths. <br> The fourth experiment investigated whether predatory invertebrates would consume tadpole eggs, including tadpoles at the earliest free swimming stage where they might still be considered eggs. Response variables are tadpoles remaining and eggs remaining.

本研究共开展四项实验，其中两项于池塘中型实验生态系统（pond mesocosms）中开展，另外两项于实验室环境中进行。
池塘中型实验生态系统相关实验旨在探究新西兰外来物种尤氏雨滨蛙（*Litoria ewingii*）的蝌蚪是否会对池塘生态系统的各项特征产生影响。
第一项实验采用析因方差分析（factorial ANOVA）设计，设置捕食性无脊椎动物存在与否与蝌蚪存在与否的交叉实验组，共设置多项响应变量：溶解氧、底栖藻类、植物生物量、多物种无脊椎动物丰度、陆生叶片分解速率、剩余蝌蚪数量以及细颗粒有机物质（FPOM）与粗颗粒有机物质（CPOM）含量。
第二项实验为每个实验水箱设置遮光与非遮光两种处理，并与蝌蚪密度梯度形成交叉实验设计，测定指标包括浮游植物、植物生物量、溶解氧、pH值以及电导率。
第三项实验测定了不同体长蝌蚪所排泄的氨氮（ammonia-N）含量。
第四项实验探究了捕食性无脊椎动物是否会取食蝌蚪卵，包括仍可被视为卵阶段的最早自由游泳期蝌蚪。响应变量为剩余蝌蚪数量与剩余卵数量。