Effects of subsidy quality on reciprocal subsidies: how leaf litter species changes frog biomass export
Effects of subsidy quality on reciprocal subsidies: how leaf litter species changes frog biomass export
复制标题
补贴质量对互惠补贴的影响：落叶层物种如何改变青蛙生物量出口
作者：
J. Earl;Paula O. Castello;Kara E. Cohagen;R. D. Semlitsch
空间补贴是一种从一个生态系统转移到另一个生态系统的资源，它可以极大地影响接收系统。众所周知，增加补贴数量会增加这些影响，但补贴质量可能也很重要。研究了池塘生态系统中凋落叶质量（不同营养物质和单宁含量）对灰树蛙生物量输出、水质和生态系统过程的影响。我们使用的凋落物来自密苏里州三种不同的原生树种[白栎（Quercus alba）、北红栎（Quercus rubra）和糖枫（Acer saccharum）]、一种非原生树种[白松（Pinus strobus）]和一种常见的水生草[草原草（Spartina pectinata）]。我们发现凋落叶种类几乎影响了我们测量的每一个变量。灰树蛙的生物量输出在有草凋落物的中生态系统中最大，在有白栎凋落物的中生态系统中最低。高单宁浓度（或可能的相关变量，溶解氧）通过对生存的影响影响生物量输出的差异，并通过改变平均体重的初级产量影响生物量输出。凋落物种类的影响往往可以追溯到凋落物本身的特征：叶片氮、磷和单宁含量，这凸显了植物功能性状在影响水生生态系统中的重要性。这项工作和其他工作强调，森林物种组成的变化可能极大地影响水生系统和水陆联系。
Spatial subsidies are resources transferred from one ecosystem to another and which can greatly affect recipient systems. Increased subsidy quantity is known to increase these effects, but subsidy quality is likely also important. We examined the effects of leaf litter quality (varying in nutrient and tannin content) in pond mesocosms on gray treefrog (Hyla versicolor) biomass export, as well as water quality and ecosystem processes. We used litter from three different tree species native to Missouri [white oak (Quercus alba), northern red oak (Quercus rubra), and sugar maple (Acer saccharum)], one non-native tree [white pine (Pinus strobus)], and a common aquatic grass [prairie cordgrass (Spartina pectinata)]. We found that leaf litter species affected almost every variable we measured. Gray treefrog biomass export was greatest in mesocosms with grass litter and lowest with white oak litter. Differences in biomass export were affected by high tannin concentrations (or possibly the correlated variable, dissolved oxygen) via their effects on survival, and by primary production, which altered mean body mass. Effects of litter species could often be traced back to the characteristics of the litter itself: leaf nitrogen, phosphorus, and tannin content, which highlights the importance of plant functional traits in affecting aquatic ecosystems. This work and others stress that changes in forest species composition could greatly influence aquatic systems and aquatic–terrestrial linkages.