Coupling biogeochemical cycles across ecosystem boundaries: The importance of terrestrial inputs to aquatic consumers and food webs

Background/Question/Methods External biogeochemical inputs to ecosystems include both inorganic nutrients as well as complex organic matter.  Organics provide both important energy subsidies as well as nutrients that subsidize production and stabilize ecosystem metabolism.  Across landscape gradients low-lying ecosystems receive the greatest subsides of allochthonous organic matter

Results/Conclusions Hence, the cycling and stoichiometry of C, N, and P within aquatic ecosystems are strongly influenced by inputs of terrestrial dissolved and particulate organic matter.  These systems may have carbon to nutrient ratios far above Redfield but are also productive.  Recent studies using stable isotopes of carbon, nitrogen, and hydrogen provide quantitative estimates of consumer support by allochthonous organic matter.  Recent theoretical analyses suggest these subsidies influence ecological interactions.  Specifically, ecosystems with high allochthonous inputs have the strongest trophic cascades.