Pollinator richness, pollination and plant reproduction are analyzed in a fragmentation gradient of the Chaco forests of Córdoba, Argentina

Abstract

We expect to find direct relationships between pollinator richness, these two processes and the area of the fragments. Considering data obtained by many researchers for different forest sites, the following objectives were planned: i) to evaluate the relationship between fragment area, pollinator richness and pollination (measure as frequency of visits to the flowers), ii) to analyze at the species level the response patterns of variables related to the pollination (pollinator richness or frequency of visits) and reproduction (i.e., fruit production) processes within a gradient of fragmentation for many plants, iii) to compare trends obtained using different methodologies, and iv) to discuss results in the context of biodiversity conservation. Contrarily to our expectations, direct relationships between fragment area and pollinator richness or frequency of floral visits were not found. On the other hand, results obtained for pollinator richness and fruit set by meta- analyses showed significant overall fragment size effect. The frequency of visits, on the contrary, did not show a significant overall size effect. The trends observed using the two methodologies were not uniform. Pollinator and plant responses to fragmentation seem to be more complex than what was originally predicted. If the heterogeneity of trends found for many species within a fragmentation gradient is analyzed, a species-specific susceptibility is suggested. In addition, many species have showed variability among seasons in their tendencies within the gradient of fragmentation. When discussing conservation politics of the Chaco forests of Córdoba, it would be interesting to analyze those plant species and their pollinators that seem to be affected negatively by reduction of fragment size.