Microclimatic changes and the indirect loss of ant diversity in a tropical agroecosystem

Recent changes in the coffee agroecosystem of Costa Rica were used to study the mechanism of biodiversity loss in transforming agroecosystems, focusing on the ground-foraging ant community. Coffee farms are being transformed from vegetationally diverse shaded agroforestry systems to unshaded coffee monocultures. We tested the hypothesis that the high-light environment and lack of leaf litter cover in the unshaded system are the determinants of the differences in ground-foraging ant diversity. Four treatments were established within the light gaps of a shaded plantation: shade, leaf litter, shade plus leaf litter, and a control (no shade or leaf litter added). Ants were sampled using tuna fish baits and light and temperature were measured. Shade and leaf litter had a significant effect on the ant fauna but probably for indirect reasons having to do with species interactions. In both shade treatments, Solenopsis geminata , the tropical fire ant, decreased significantly while the other species increased. The possibility that the physical factor changes the nature of competitive interactions between the most abundant species is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47696/1/442_2004_Article_BF00333736.pd

Determining barriers to sustainability within the Costa Rican coffee industry

The Costa Rican coffee industry has been the subject of many sustainability plans, all of which have had a particular bias towards one aspect of sustainability or another. Following the sustainability evaluation framework discussed in previous work a significant gap was recognized between the requirements of a sustainable industry, which address all facets of sustainability (including all stakeholders - both producers and processors), and the present system. This was particularly so within aspects of institutional considerations and the lack of continuity when integrating processing considerations into sustainability considerations. The concerns, deficiencies and perceptions of the various stakeholders within the industry were documented in order to ensure a proper match between sustainability barriers and any steps that would be taken to address them. The inclusion of stakeholders' thoughts and perceptions was determined to be important in the establishment of any policy aimed at improving the overall sustainability of the coffee industry. Using the sustainability framework as the foundation for discussion, specific barriers to the application of sustainability were highlighted and discussed. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.