Carbon turns over much faster through basal food-chain levels in aquatic than in terrestrial ecosystems

Global temperatures have increased dramatically over the past century, which is causing major impacts on climate patterns, ocean circulation and wildlife preservation. The increase in temperature is largely due to a rise of anthropogenic emissions of greenhouse gases, of which CO2 is one of the most important.

To understand the capacity of ecosystems to sequester excesses of atmospheric CO2 and improve our ability to predict future climate change scenarios, we must first improve our knowledge of how carbon moves through the food chain of aquatic and terrestrial ecosystems.

In the March issue of Ecology Letters, Cebrian shows that aquatic ecosystems turn over carbon through the basal levels of the food chain at a more than ten times faster rate than do terrestrial ecosystems. This means that carbon stored in basal trophic levels is released back to the atmosphere or transferred to higher trophic levels much more quickly in aquatic than in terrestrial ecosystems. Thus, aquatic ecosystems should have a much lower capacity for retaining carbon in situations of higher CO2 availability. These results help refine current and future estimates of global carbon cycling and implications on climate change.