As agriculture continues to expand across the tropics there is an urgent need to assess its effects on biodiversity and understand how to reconcile agricultural expansion with conservation and overall sustainable development. Protected areas are not large enough to sustain viable mammal populations, thus it is important to understand how to integrate agricultural regions into conservation strategies. The aims of this thesis were (1) to improve our understanding of jaguars and other medium-large terrestrial mammals across increasing agricultural landscapes; (2) assess the impact of human land uses such as oil palm cultivation on these species; and (3) inform strategies to reconcile biodiversity conservation with other sustainability aspects and regional development in rural areas in Colombia. The methods included field surveys using camera trapping, ecological analysis (e.g. capture-recapture and occupancy models), and scenario and network analysis combined with sustainability assessment.
The findings conclude that there is an effect of agriculture on jaguar populations as densities were lower than in comparable natural areas, however there were resident individuals and breeding, highlighting that modified areas can be important for jaguar long-term survival and connectivity. Wetlands were the only variable explaining jaguar occurrence, while forests impacted puma's occupancy positively and were a predictor of mammal species richness. Conversely, both oil palm and pasture affected several mammal species negatively, and the remaining ones only displayed limited affinity to these land covers, showing that the expansion of oil palm plantations and pastures constitutes a threat for felids and mammals in general. These results suggest that maintaining natural areas such as forests and wetlands across agricultural regions is key to mammal survival, pointing at a land sparing strategy. Further oil palm expansion, when inevitable, should occur on pastures since they displayed limited to no conservation value for jaguars and other mammals.
Overall, agriculture impacts mammal communities by decreasing their diversity and evenness, while increasing dominance, comparatively to pristine regions. The effect on species richness was not entirely evident, demonstrating that agricultural regions are not necessarily biological deserts. Data also show that jaguars did not affect the occupancy of other felid species and were a positive predictor of mammal species richness, hence conservation strategies focused on this declining keystone species can benefit the wider mammal community, even in modified regions.
This thesis also highlights that rural areas can provide for both people and wildlife if the right conditions are in place. Under the current situation the main agricultural sectors (i.e. cattle ranching and oil palm cultivation) affect wildlife and other aspects of sustainability negatively. Both adopting a stronger regulatory framework with land use planning and applying incentive schemes are improvements, as they would enable to maintain natural habitats that are crucial for jaguar and other species, while improving overall sustainability. Relevant recommendations to reconcile biodiversity conservation with overall sustainable development include the design and adoption of strategic land use planning, making agricultural subsidies conditional to social and environmental standards, consolidating local institutions, designing incentives to foster the implementation of good agricultural practices, favouring small farmers, and creating a demand for certified agricultural commodities. Finally, this research proves that achieving conservation across agricultural regions is inherently complex. Interdisciplinary approaches are needed to study such landscapes and provide solutions that are effective and locally-relevant
