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KLIMAFORSK-Stort program klima

Cascading consequences of hunting and fishing for ecosystem services in Amazonian forests

Alternative title: Kaskadeeffekter av jakt og fiske på økosystemtjenester i Amazonas

Awarded: NOK 19.8 mill.

Hunting and fishing is the basis of life for indigenous peoples and other local people in the Amazon. In recent times, uncontrolled hunting and fishing has led to a sharp decline in populations of wildlife and fish in many places across this region. Solutions to hunting and fisheries management are therefore essential to enable the preservation of fundamental ecosystem services, such as food security and biodiversity. In addition, understanding impacts of hunting and fishing on tropical forest carbon stocks is important for the global climate and appropriate implementation and monitoring of REDD+ programs. This project investigates the extent to which harvest of large-bodied terrestrial and aquatic species that feed on forest fruits is a driver of carbon stock change in undisturbed Amazonian forests. The project investigates the implications of the disappearance of such animals to carbon stocks in undisturbed Amazonian forests. We are also quantifying the effects of fisheries management undertaken by local communities. To achieve this, we will take advantage of two unique and existing natural experiments: 1) a 50-year old Amazonian-wide network of tree plots that predate modern human disturbances and 2) an existing fish management arrangement on the Juruá river floodplain, where a large number of oxbow lakes are managed under three different levels of protection. Re-sampling trees from a select set of forest plots across the Brazilian Amazon will allow us to examine changes in forest composition and carbon stocks over five decades. By examining the distribution and abundance of commercially valuable fish species across lakes with different levels of protection, we will be able to test the effectiveness of the local fisheries management. So far, we have sampled 44 forest plots from 15 different locations across the Amazon, mapping, measuring and identifying almost 30.000 trees from at least 300 genera in 70 families. In addition, we are doing extensive surveys of other taxa and have detected 31 large vertebrate species. However, the identification work for many groups is difficult and tedious. So far, we have prepared over 100,191 dung beetle specimens from the first seven locations and appear to have at least 5 species new to science in our dung beetle samples. Other beetles have been processed from 3 locations and this includes 3800 specimens belonging to 56 Coleoptera families and more than 1200 different species. This underlines the challening diversity we are faced with. We have also sampled DNA from carrion flies and water to assess the direct impact of hunting and fishing on the terrestrial and aquatic fauna, respectively. The latter work has included extensive genotyping of the fish fauna from the Juruá river floodplain (and this is now being finalized) so that we can detect changes in fish community structure across lakes via DNA in water samples. These water samples are now being sequenced.

The proposed project aims to investigate the degree to which (over)harvest of large-bodied terrestrial and aquatic frugivores is an anthropogenic driver of carbon stock change in structurally undisturbed Amazonian forests, and elucidate the implications of defaunation to carbon stocks in otherwise undisturbed tropical forests. We will also quantify the effects of community-based fishing management and establish a similar experimental system of ‘no-take’ areas for hunting activities. To achieve this, we will take advantage of two unique and existing natural experiments at a basin-wide and local scale: 1) a 50-year old basin-wide network of tree plots that predate modern human disturbances and 2) an existing fish management arrangement on the Juruá river floodplain, where a large number of oxbow lakes are managed under three different levels of protection. Re-sampling trees and saplings from a select set of 102 forest plots across the Brazilian Amazon will allow us to examine changes in forest composition and aboveground biomass/carbon stocks over five decades. By relating this to hunting and fishing pressure, and other environmental gradients, we will detect the drivers of potential change. The direct impact of hunting and fishing on the terrestrial and aquatic fauna will be quantified via metabarcoding analysis of DNA from carrion flies and water samples, respectively. Examining the distribution and relative abundance of commercially valuable fish species across lakes with different levels of protection will allow us to test the effectiveness of local fisheries management. Understanding impacts of hunting and fishing on tropical forest carbon stocks is important for the global climate and appropriate implementation and monitoring of REDD+ programs. Solutions to hunting and fisheries management are also essential to enable the preservation of fundamental ecosystem services, such as food security, biodiversity, or carbon storage in Amazon forest environments.

Funding scheme:

KLIMAFORSK-Stort program klima