Abstract
This paper evaluates the post-dispersal artificial seed predation rates in two areas of the southeastern Amazon forest-savanna boundary, central Brazil. We conducted the survey in a disturbance regime controlled research site to verify if exists an edge effect in these rates and if the disturbance (in this case annual fire and no fire) affects seed predation. We placed 800 peanuts seeds in each area at regular distance intervals from the fragment`s edge. Data were analyzed by a likelihood ratio model selection in generalized linear models (GLM). The complete model (with effects from edge distance and site and its interaction) was significative (F3=4.43; p=0.005). Seeds had a larger predation rates in fragment's interior in both areas, but in the controlled area (no disturbance) this effect was less linear. This suggests an edge effect for post-dispersal seed predation, and that disturbances might alter these effects. Even if we exclude the site effect (grouping both areas together) there is still a strong edge effect on seed predation rates (F3=32.679; p>0.001). We did not verify predator's species in this study; however, the presence of several species of ants was extremely common in the seeds. The detection of an edge effect in only a short survey time suggests that there is heterogeneity in predation rates and that this variation might affect plant recruitment in fragmented areas of the Amazon forest. Henceforth, this seed predation should be taken in consideration in reforestation projects, where the main source of plants species is from seed distribution.
Highlights
Post-dispersal seed predation is an important factor regulating plant community composition and structure (Diaz et al, 1999; Nathan and Muller-Landau, 2000; Baldissera and Ganade, 2005)
The utilization of peanuts, an exotic species – was made with the intent to verify the seed predation rates excluding the possibility of conduct the survey with a local seed species that might be associated with a specific predator, which might have created a bias in the results (Burkey, 1993; Wong et al, 1998)
The results of the generalized linear models (GLM) presented an over dispersion (3.33, when it should be 1.0 for this family), so we choose to apply a quasi-likelihood (Quasi-Poisson) method that allows over dispersion, adjusting the dispersion to approximate the estimated parameters
Summary
Post-dispersal seed predation is an important factor regulating plant community composition and structure (Diaz et al, 1999; Nathan and Muller-Landau, 2000; Baldissera and Ganade, 2005). Alterations in environmental quality are stronger in fragments since there is a larger proportion of an edge habitat in small fragments in relation to large continuous areas (Hoover et al, 1995). These alterations can have a direct effect on local plant recruitment, through microclimatic alterations – humidity, light, and temperature – or an indirect effect, by changing activity and behavior of predator’s species (Diaz et al, 1999)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
