Collaborative Research: Elevated Atmospheric CO2 Alters Plant Detritus Nutritional Quality: Effects on Microbial and Detritivore Food Webs in Aquatic Ecosystems

大气二氧化碳浓度升高改变植物碎屑的营养质量：对水生生态系统中微生物和食腐动物食物网的影响化石燃料燃烧产生的大气二氧化碳浓度升高直接影响树叶的光合作用速率、生长和化学组成。 研究人员已经证明，当白杨树生长在二氧化碳水平升高的环境中时，它们的叶子含有较少的氮和较高浓度的植物防御化合物（酚类化合物，木质素和单宁），这使得它们对动物和微生物消费者的营养较少。 由于小源头流在森林景观严重依赖树叶凋落物，以燃料的食物网，平行的现场和实验室研究将测量的影响，CO2引起的变化，白杨叶凋落物的食物质量将对流细菌，真菌和无脊椎动物消费者的生长和繁殖。 微生物和无脊椎动物生长速度的差异反过来又会影响水生生态系统中的食物网结构和功能以及碳动态。

Abstract0128504WetzelCollaborative Research: Elevated Atmospheric CO2 Alters Plant Detritus Nutritional Quality: Effects on Microbial and Detritivore Food Webs in Aquatic Ecosystems.Elevated atmospheric carbon dioxide (CO2) resulting from the combustion of fossil fuels, directly affects the photosynthesis rate, growth, and chemical make-up of tree foliage. The investigators have demonstrated that when aspen trees are grown under elevated CO2 levels, their leaves contain less nitrogen and higher concentrations of plant defense compounds (phenolic compounds, lignins and tannins), which renders them less nutritious to their animal and microorganism consumers. Since small headwater streams in forested landscapes rely heavily on tree leaf litter to fuel their food webs, parallel field and laboratory studies will measure the effect that the CO2-induced change in food quality of aspen leaf litter will have on the growth and reproduction of stream bacteria, fungi, and invertebrate consumers. The difference in microbial and invertebrate growth rates in turn could affect food web structure and functions and carbon dynamics in aquatic ecosystems.