Banca de DEFESA: ANDRESSA BÁRBARA SCABIN

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANDRESSA BÁRBARA SCABIN
DATE: 30/07/2020
TIME: 14:00
LOCAL: Defesa online sítio: https://conferenciaweb.rnp.br/webconf/webconf-pop-rn-sala-a.
TITLE:

Cascading effects of hunting on vertebrates and plant communities in Amazonian forest landscapes 


KEY WORDS:

Hunting; empty forest; defaunation, density compensation; frugivory, seed dispersal; functional traits; carbon storage; Amazonia


PAGES: 126
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Overhunting is one of the greatest threats to wildlife worldwide and has caused a sharp decline in the abundance of large-bodied vertebrate populations in tropical forests. The implications are far-reaching since the most intensely hunted species are often involved in key ecological processes related to forest dynamics, including seed dispersal and predation. Defaunation disrupts these plant-animal interactions, which are essential for forest regeneration, and can compromise the maintenance of plant diversity and ecosystem services. This thesis explores the cascading effects of defaunation on vertebrate and plant communities using a hunting pressure gradient in the Médio Juruá region of western Brazilian Amazonia. In the first chapter, we analysed the direct and indirect effects of hunting on mammal and bird communities. For this, we estimated vertebrate biomass using camera trapping in both the understory and forest canopy at 30 sites distributed along the hunting gradient. Overhunted forests showed changes in the size structure of the animal community with a decline in the biomass of hunting-sensitive species and an increase in the abundance of nocturnal rodents, possibly related to a density compensation mechanism. The second chapter explores the cascading effects of defaunation on future forest composition and functionality. We compared functional traits of trees and saplings, inventoried in 30 plots of 0.25 ha (=7.5 ha) established along the hunting gradient, to test for an expected decrease in traits associated to seed dispersal by large vertebrates. Our results indicated a modest decrease in the abundance of large vertebrate dispersed saplings compared to conspecific trees, and an increase in the prevalence of saplings from abiotically dispersed species. However, this effect did not reflect the community-wide pattern for the continuous traits of wood density, leaf mass/area (LMA) and seed mas. In the third chapter, we used dendrometric data from our forest inventory and comprehensive wood density sampling to estimate current and future carbon stocks, and thereby assess the potential impact on carbon stocks in intensively hunted forests. Of the 30 plots sampled, 22 could lose forest carbon in the future and the mean projected loss was 2.2 MgC ha-¹. For two protected areas (PAs) in the study landscape, the projected loss was approximately 1,560 MgC. Considering the currently predicted monetary values in the international carbon market, the projected decrease in the PAs future carbon stock was valued at US$15,600 to US$120,000.


BANKING MEMBERS:
Externa à Instituição - RICARDO SIQUEIRA BOVENDORP - UESC
Externa à Instituição - CARINE EMER - ICMBio
Interno - 1837921 - ALEXANDRE FADIGAS DE SOUZA
Presidente - 170.103.572-34 - CARLOS AUGUSTO DA SILVA PERES - NENHUMA
Externo ao Programa - 316.466.258-03 - JOÃO VITOR CAMPOS E SILVA - UFAL
Externa à Instituição - MAÍRA BENCHIMOL DE SOUZA - UESC
Notícia cadastrada em: 13/07/2020 14:52
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