Environmental Conservation Across Ecosystem Boundaries: Connecting Management And Funding
A Thesis Submitted for the Degree of PhD at the University of St Andrews:
Environmental degradation is accelerating worldwide, yet environmental conservation remains limited by funding. Tackling this limitation requires not only absolute increases in funding, but improved prioritisation of actions. On a global scale island ecosystems are of high priority, with invasive species one of their most significant threats. In this thesis I investigate prioritisation of invasive grazing species control, incorporating ecological, economic, and social concerns, on the island of Bonaire, Caribbean Netherlands. To enable the trade-off of potential grazer control options for their ecological impacts I modelled the relationship between of grazer density and vegetation, and watershed vegetation and the coral reef. I found negative relationships for goat and pig grazing with grass presence, and for donkey grazing with ground cover. Coral cover below 10m showed a positive relationship to ground cover, and, surprisingly, a negative relationship to tree biomass. Because conservation action is most likely to be sustainable when connected to funding, I conducted choice experiments with SCUBA divers, which estimated a positive willingness to pay for reef health improvements achieved using terrestrial grazer control. Through communication with local policy makers and practitioners I identified three options for grazer control, eradication, population reduction, or fencing, and estimated costs and social acceptability for each option. Though the ecological models predicted eradication to have the highest impacts on the terrestrial and marine ecosystem, lower costs and higher social acceptability identified fencing as the most suitable option for grazer control on Bonaire in the short term, with the potential to be funded through a fee on SCUBA divers. Through linking ecological, economic, and social considerations within a real world conservation context I illustrate the importance of looking beyond only ecological improvements when prioritising conservation action. This research is directly applicable to policy and practise on Bonaire.
Chapter 1 Literature Review
Chapter 2 Impacts of introduced grazing species on terrestrial ecosystems
Chapter 3 Impacts of vegetation cover on coral reef health
Chapter 4 User fees across ecosystem boundaries: Are SCUBA divers willing to pay for terrestrial biodiversity conservation?
Chapter 5 Prioritising conservation actions
Chapter 6 Discussion