Valuing the economic impacts of seed dispersal loss on voluntary carbon markets

Abstract

Seed dispersal is an ecosystem service strongly affected by the loss of mutualist dispersers, with economic consequences in terms of carbon sequestration and climate change mitigation policies. Especially, large frugivores are important contributors to carbon sequestration because they are the main disperser of large-seeded trees, which store a high amount of carbon. The effect of seed dispersers defaunation on carbon sequestration is particularly significant in tropical forests, where frugivores disperse 70–94% of the woody plant species and where ∼59% of the world's forest carbon above ground is stored. However, the economic impacts of the defaunation of large frugivores on ecosystem services, such as seed dispersal and carbon sequestration, are poorly valued. Here, we simulate the effects of the loss of three large frugivores (Brachyteles arachnoides, Alouatta guariba, and Pipile jacutinga) on the recruitment of hardwood tree species and its economic impact on carbon markets. We found that the combined loss of the large frugivores would reduce the standing carbon sequestration by 2.5%. However, defaunation also affects seed predator communities, which influences the contribution of the frugivores. By adding the loss of large seed predators, the reduction in carbon sequestration would rise to 3.5%. In summary, the potential economic contribution of the seed dispersal services provided by our target dispersers ranges from US$3.94 ha−1 year−1 to US$15.42 ha−1 year−1. We highlight the importance of conserving seed disperser and predator communities to guarantee the long-term viability of forest carbon sequestration. We argue that knowledge of the economic consequences of defaunation should be included in carbon mitigation policies and encourage animal conservation and forest restoration.