Periodic Reporting for period 1 - Lost-Biodiv (Predicting changes in species interactions following species loss in hydroelectric reservoir islands)
Okres sprawozdawczy: 2019-12-01 do 2021-11-30
Habitat loss, fragmentation and subsequent degradation are primary drivers of biodiversity loss worldwide. In the tropics, hydropower development is a major cause of habitat loss and fragmentation, often creating vast archipelagic landscapes, in which forest islands are isolated within a uniformly hostile open-water matrix. In these archipelagic landscapes, island taxa typically experience a novel hyper-disturbance regime, resulting in drastic shifts in species diversity and community composition through species extinction and turnover. Nevertheless, the burgeoning energy demand worldwide is currently leading to a proliferation of hydroelectric dams across tropical developing countries, which have become the new hydropower frontiers.
Here we aimed to demonstrate how pervasive hydropower development has been for biodiversity and ecosystem functioning. With this, we expected to raise European awareness of a problem that affects the entire humanity, and one in which Europe has considerable responsibility as it is one of the main importers of products from developing countries that are directly or indirectly derived from hydropower. With this project we expected to generate knowledge to give foundation to questions such as where to build new dams, whether to create protected areas near hydroelectric reservoirs, and whether to avoid the construction of dams according to the spatial arrangement of the created islands and instead prioritize alternative renewable energy sources. Similarly, policymakers will be able to improve their management policies in widespread European and worldwide fragmented landscapes. NGOs will also take advantage of outcomes of our project, for example, by adopting the methods to be tested in this project, assessing predator-prey interactions to infer on ecosystem functioning, which is simpler than deploying exhaustive census of several taxonomic groups.
The initial objective of this Marie-Skłodowska-Curie Action was to dissect the ecological impacts of habitat insularization induced by hydroelectric dams on ecosystem functioning, by comprehensively assessing species interactions across 35 forest islands and three mainland continuous forest sites across one of the largest hydroelectric reservoirs in South America - the Balbina Hydroelectric Reservoir in Central Brazilian Amazon. Firstly, specific prey-predator interactions – herbivory, insectivory and seed predation – would be quantified in situ and related to patch, landscape and habitat-quality metrics. Then, species interactions across terrestrial food webs would be evaluated using theoretical approaches based on species co-occurrence and co-dispersion analysis.
Given the impossibility of carrying out any fieldwork during the period of this project (given the COVID-19 pandemic), we have modified the original objectives to:
(I) Consider multiple scales and dimensions of diversity to examine the effects of habitat loss and insular fragmentation on lizard and small mammal assemblages
(II) Evaluate the effects of habitat loss and insular fragmentation on snake assemblages
(III) Examine responses of a major herbivore, the leaf-cutter ants, to habitat loss and fragmentation, and their inter-trophic relationships
(IV) Apply species-habitat networks to investigate the effects of habitat loss and insular fragmentation on eight major biological groups
Overall, we conclude that hydropower development, by creating small, habitat-degraded islands that harbour reduced taxonomic, functional and phylogenetic diversity of species, has major detrimental effects on biodiversity. To preserve the multiple dimensions of species diversity, thereby maintaining the health of the ecosystem, setting-aside large forest tracks should be imperative.
Here we aimed to demonstrate how pervasive hydropower development has been for biodiversity and ecosystem functioning. With this, we expected to raise European awareness of a problem that affects the entire humanity, and one in which Europe has considerable responsibility as it is one of the main importers of products from developing countries that are directly or indirectly derived from hydropower. With this project we expected to generate knowledge to give foundation to questions such as where to build new dams, whether to create protected areas near hydroelectric reservoirs, and whether to avoid the construction of dams according to the spatial arrangement of the created islands and instead prioritize alternative renewable energy sources. Similarly, policymakers will be able to improve their management policies in widespread European and worldwide fragmented landscapes. NGOs will also take advantage of outcomes of our project, for example, by adopting the methods to be tested in this project, assessing predator-prey interactions to infer on ecosystem functioning, which is simpler than deploying exhaustive census of several taxonomic groups.
The initial objective of this Marie-Skłodowska-Curie Action was to dissect the ecological impacts of habitat insularization induced by hydroelectric dams on ecosystem functioning, by comprehensively assessing species interactions across 35 forest islands and three mainland continuous forest sites across one of the largest hydroelectric reservoirs in South America - the Balbina Hydroelectric Reservoir in Central Brazilian Amazon. Firstly, specific prey-predator interactions – herbivory, insectivory and seed predation – would be quantified in situ and related to patch, landscape and habitat-quality metrics. Then, species interactions across terrestrial food webs would be evaluated using theoretical approaches based on species co-occurrence and co-dispersion analysis.
Given the impossibility of carrying out any fieldwork during the period of this project (given the COVID-19 pandemic), we have modified the original objectives to:
(I) Consider multiple scales and dimensions of diversity to examine the effects of habitat loss and insular fragmentation on lizard and small mammal assemblages
(II) Evaluate the effects of habitat loss and insular fragmentation on snake assemblages
(III) Examine responses of a major herbivore, the leaf-cutter ants, to habitat loss and fragmentation, and their inter-trophic relationships
(IV) Apply species-habitat networks to investigate the effects of habitat loss and insular fragmentation on eight major biological groups
Overall, we conclude that hydropower development, by creating small, habitat-degraded islands that harbour reduced taxonomic, functional and phylogenetic diversity of species, has major detrimental effects on biodiversity. To preserve the multiple dimensions of species diversity, thereby maintaining the health of the ecosystem, setting-aside large forest tracks should be imperative.
The project was developed as initially proposed during the first three months. That included:
- Defining sampling design to be adopted in the species-interactions experiments
- Apply for a fieldwork permit
- Organising of a symposium on the impacts of hydropower development on biodiversity
Due to the pandemic, the proposed fieldwork and secondment in the Aarhus University under the supervision of the Prof Jens Svenning were cancelled, as well as All the conferences (e.g. ATBC2020 and European Conference on Tropical Ecology), and any training (e.g. Species Distribution Modelling course in Evora, Portugal, or the course on Structural Equation Modelling, in Glasgow, UK). The tasks included in each of the objectives were carried out in the following months:
(I) 4 - 7th
(II) 8th
(III) 9th-13st
(IV) 14nd - 18th
We highlight that each objective added new skills to the ER. For example, in (I), Dr Palmeirim learned to pursuit functional and phylogenetic analysis of biodiversity data; in (III) she learned to perform foodweb analysis using structural equation modelling, and in (IV) learned the network theory.
A brief overview, exploration and dissemination of the results follows for each of the newly defined objectives:
- Objective I: We showed the detrimental effects of insular fragmentation on the taxonomic, functional and phylogenetic dimensions of diversity of small mammals and lizards, as presented in the ATBC2021; currently under review in Landscape Ecology
- Objective II: We showed that even poorly detected organism such as snakes show species-area relationships under insular fragmentation. Published in Tropical Conservation Science.
- Objective III: Biodiversity in the insular fragmented landscape of Balbina is likely to be governed by bottom-up rather than top-down forces. Published in Ecosphere and to be orally disseminated in the International Congress on Conservation Biology 2021.
- Objective IV: Species-habitat networks in Balbina are poorly connected, modular and robust and highly nested. To be submitted to Ecology Letters and disseminated in the Symposium on Ecological Networks 2021.
- Defining sampling design to be adopted in the species-interactions experiments
- Apply for a fieldwork permit
- Organising of a symposium on the impacts of hydropower development on biodiversity
Due to the pandemic, the proposed fieldwork and secondment in the Aarhus University under the supervision of the Prof Jens Svenning were cancelled, as well as All the conferences (e.g. ATBC2020 and European Conference on Tropical Ecology), and any training (e.g. Species Distribution Modelling course in Evora, Portugal, or the course on Structural Equation Modelling, in Glasgow, UK). The tasks included in each of the objectives were carried out in the following months:
(I) 4 - 7th
(II) 8th
(III) 9th-13st
(IV) 14nd - 18th
We highlight that each objective added new skills to the ER. For example, in (I), Dr Palmeirim learned to pursuit functional and phylogenetic analysis of biodiversity data; in (III) she learned to perform foodweb analysis using structural equation modelling, and in (IV) learned the network theory.
A brief overview, exploration and dissemination of the results follows for each of the newly defined objectives:
- Objective I: We showed the detrimental effects of insular fragmentation on the taxonomic, functional and phylogenetic dimensions of diversity of small mammals and lizards, as presented in the ATBC2021; currently under review in Landscape Ecology
- Objective II: We showed that even poorly detected organism such as snakes show species-area relationships under insular fragmentation. Published in Tropical Conservation Science.
- Objective III: Biodiversity in the insular fragmented landscape of Balbina is likely to be governed by bottom-up rather than top-down forces. Published in Ecosphere and to be orally disseminated in the International Congress on Conservation Biology 2021.
- Objective IV: Species-habitat networks in Balbina are poorly connected, modular and robust and highly nested. To be submitted to Ecology Letters and disseminated in the Symposium on Ecological Networks 2021.
Bellow, we indicate each of the outcomes of this project corresponding to the four modified objectives:
(i) Forest area predicts all dimensions of small mammal and lizard diversity in Amazonian insular forest fragments
(ii) Species-area relationships induced by forest habitat fragmentation apply even to rarely detected organisms
(iii) Drivers of leafcutter ant populations and their inter-trophic relationships in Amazonian forest islands
(iv) On the emerging properties of species-habitat networks in fragmented landscapes: a multi-taxa analysis
In terms of socio-economic impacts, our results support that any economic benefit raising from hydropower development in tropical developing countries should be considered against their ecological negative impacts, in addition to the social impacts. Due to the impossibility of collecting new data, we were not able to demonstrate the detrimental impacts of biodiversity loss resulting from the habitat loss and insular fragmentation as induced by the Balbina Hydroelectric Reservoir, on the delivery of ecosystem services. Nevertheless, our results still suggest that ecosystem functioning and therefore the ecosystem services provided might be strongly impacted by the construction of hydroelectric reservoirs that both flood over large expanses and create a myriad of small islands (< 100 ha) that are subject to further habitat degradation from strong edge effects. We therefore call the attention of the decision-makers that allow investor on the hydropower sector from Europe in such countries.
(i) Forest area predicts all dimensions of small mammal and lizard diversity in Amazonian insular forest fragments
(ii) Species-area relationships induced by forest habitat fragmentation apply even to rarely detected organisms
(iii) Drivers of leafcutter ant populations and their inter-trophic relationships in Amazonian forest islands
(iv) On the emerging properties of species-habitat networks in fragmented landscapes: a multi-taxa analysis
In terms of socio-economic impacts, our results support that any economic benefit raising from hydropower development in tropical developing countries should be considered against their ecological negative impacts, in addition to the social impacts. Due to the impossibility of collecting new data, we were not able to demonstrate the detrimental impacts of biodiversity loss resulting from the habitat loss and insular fragmentation as induced by the Balbina Hydroelectric Reservoir, on the delivery of ecosystem services. Nevertheless, our results still suggest that ecosystem functioning and therefore the ecosystem services provided might be strongly impacted by the construction of hydroelectric reservoirs that both flood over large expanses and create a myriad of small islands (< 100 ha) that are subject to further habitat degradation from strong edge effects. We therefore call the attention of the decision-makers that allow investor on the hydropower sector from Europe in such countries.