Defaunation effects on carbon stock in tropical forests

Author(s)

Laura Carolina Bello Lozano

• Document type: Doctoral Thesis
• Press: Rio Claro. 2018-09-14.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro
• Defense date: 2018-07-27
• Advisor: Mauro Galetti

Abstract

Animal loss is a silent threat of forest ecosystem. Tropical forests are becoming defaunated ecosystems, especially defaunated of large animals. The loss of animals goes beyond than the loss of charismatic animals, what we are losing are key interactions that modulate the functionality of the forest and therefore of the associated ecosystem services. For instance, defaunation have effects over seed dispersal, nutrient cycling, water quality and dung removal among others ecosystem services. In this thesis, we explore the potential effects of defaunation of large animals in carbon stock ecosystem services of tropical forest. We found that the carbon stock ecosystem service is supported by large animals due to large frugivores are the main dispersers of large-seeded trees and, large-seeded trees tend to be tall trees with dense wood, therefore, store high quantities of carbon. Hence, the removal of large-seeded trees from the forest, because of diminished dispersal induced by the lack of large frugivores, reduce the carbon stock potential of the forest. However, the reduction is not straightforward because smaller frugivores can partially compensate for the loss of large frugivores. Moreover, strong defaunation effects in the seed predators communities can also affect the carbon stock potential of the forest. In strongly defaunated communities small rodents tend to increase their abundance and the predation pressure over large seeds, reducing their recruitment. In addition, we explore the impact of defaunation and carbon stock relation in conservation programs. We show that restoration projects are promoting defaunated ecosystems because they are dominated by abiotic trees or small-seeded trees, which will not provide enough food to large animals. Besides we observed that the lack of large animals can produce economic impacts in the carbon markets. Therefore, we argue the urgent necessity of integrating the animal role in restoration and climate mitigation strategies to. The economic impact of animal defaunation on carbon budget is a good argument to introduce animals in REED+ markets and forest restoration strategies. Within this evidence, we claim for the development of new national and international policy frames to protect forests from ‘defaunation fronts’ as well as has been done with ‘deforestation fronts’. (AU)

• FAPESP's process: 13/22492-2 - Linking defaunation to carbon storage ecosystem services in Atlantic rainforests
• Grantee: Laura Carolina Bello Lozano
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)