Respiration in lakes

This chapter reviews, from a quantitative perspective, estimates and models of planktonic and benthic respiration in lakes, as derived from bottle and core incubations. Using data gleaned from the literature, empiricalmodels of planktonic andbenthic respiration are presented inwhich respiration is shown todepend primarily on lake trophic conditions and, secondarily, on temperature and other factors such as dissolved organic carbon loading and community structure. The possibilities and limits of alternative methods of measuring lake respiration and its components are discussed. Extrapolations of the findings to the globe suggest that about 62–76 Tmol of carbon are respired annually in the world’s lakes, exceeding the estimated gross primary production of these ecosystems. Lakes thus contribute significantly to the oxidation of landderived organic carbon.