COS 35-4
Idiosyncratic effects of gray wolf-induced trophic cascades on ecosystem carbon cycling
Predator induced trophic cascades have been shown to impact ecosystem carbon cycling, yet the magnitude and direction of these impacts have not been evaluated at large spatial scales across different terrestrial ecosystems. Here we estimate the impacts of gray wolves on ecosystem carbon cycling in wolf-moose boreal and wolf-elk grassland ecosystems in North America.
Results/Conclusions
We find that wolves cause an increase in net ecosystem productivity (NEP) of 24.0 – 52.0 g C m-2 yr-1 in boreal ecosystems, and a decrease in NEP of 30.03 – 102.88 g C m-2 yr-1 in temperate grasslands. The combined indirect impact of wolves throughout their North American range is to sequester 4.6 – 9.9 x 1013 g C yr-1 in boreal forest and release 8.8 x 1012 – 3.0 x 1013 g C yr-1 in grasslands. This is equivalent to the combined emissions of 33-71 million and 6-21 million passenger vehicles respectively. The idiosyncratic nature of these impacts provides a cautionary note that the ecosystem services of large predators need to be carefully evaluated in relation to their ecosystem context.