Recent work has suggested that freshwater ecosystems may play a significant role in the global carbon cycle, potentially emitting 1.2 Pg C y-1 to the atmosphere [1, 2]. The majority of the CO2 that is degassed from streams and rivers comes from the decomposition of allochthonous leaf litter inputs [3, 4]. The process of decomposition fuels aquatic food webs, helps to regulate surface water acidity, and links biogeochemical cycles [5, 6].