Abstract
Land use and cover change (LUCC) is considered one of the main drivers of biodiversity loss and deterioration of ecosystem services (ES) globally. Currently, the highest land conversion is occurring in tropical regions from forest to agricultural land, i.e. agriculturalisation. Tropical forests contain the highest biodiversity on Earth and are recognised as highly relevant for ES provision.Fauna provides key regulating services (e.g.pollination, natural pest and disease control and long-distance seed dispersal) the so-called faunal ecosystem services (FES). This research aimed to assess how agriculturalisation affects the distribution of FES provision and demand at pantropical scale. For this it was necessary:
a) To identify FES with potential to be spatially modelled through a comprehensive literature review, which summarises the importance of animal populations as providers of regulating ecosystem services and the identified consequences of agriculturalisation on animal populations.
b) To generate a spatial model of FES provision and demand pantropically. A pantropical pollination model was generated by combining previously suggested models with novel variables and methods, using geographic information system techniques.
c) To use a LUCC model to generate projections of future agriculturalisation in tropical regions under two scenarios of change: a conservation scenario, where deforestation is restricted to occur outside protected areas; and a non-conservation scenario, where deforestation can occur within protected areas. Constant deforestation rates were assumed for both scenarios.
d) To use the land-use change projections to model pollination service under these scenarios and quantify the changes in provision and demand due to conversion of forest to cropland.
The main findings of this research are:
•Abundance and capacity of movement of providers are highly relevant for the occurrence of some FES (i.e. pollination, natural control, seed dispersal) and determines the spatial distribution of the service. However, this could vary among ecosystem services and is context-dependent.
•The agriculturalization of forested areas can increase the service provision by wild bees in the short term. However,deforestation and cropland expansion could have a negative impact on pollination service pantropically in the long term.
•A decrease in current deforestation rates, an increase in forest protection and incorporation of natural habitats in agricultural landscapes are necessary to maintain current pollination service through time.
Enhancement of FES can have positive effects on agroecosystems, by increasing productivity and food security, and on natural systems, by reducing the pressure of agriculturalisation on both, provider and non-provider populations.
| Date of Award | 1 Jul 2020 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Mark Mulligan (Supervisor) & James Millington (Supervisor) |