Efeito da complexidade de habitats sobre a herbivoria de um Gastrópode invasor e a estrutura da comunidade perifítica.

Abstract

The habitat complexity is an important of structurer component of the biological communities, can stabilize the interactions between consumer-resource also by reducing the probability of invasion by non-native species. In our experiment, we use artificial macrophytes, simulating two types of complexity (high and low), to test the herbivory patterns of invasive species relative to native species. As variable response to herbivory patterns, we have the density, richness and chlorophyll-a periphyton community. To test the hypotheses were performed a t-test to the availability of resources. Two-way ANOVA to identify specific groups consumed, and another for herbivores to measure patterns of the gastropod and interaction with complexity. To measure locomotor patterns were performed quadratic regressions. The resource availability, we can see a higher density of algae to complex substrate, however this pattern does not hold for riches and chlorophyll-a. In relation to the consumption patterns of chlorophyll-a and species richness, we can see that structural complexity significantly affected the species consumption rate by gastropods, but this effect was dependent on the species, the most simple habitats, reduced riches and chlorophyll-a by herbivory gastropod invader. Over the locomotor behavior of gastropods, the results suggest a possible relationship between the exploitation of food resources and the rate of consumption. These results suggest that the simplification of habitats, added the invasion of species, generated an increase in the invasive species impact on the attributes of the periphyton community. These results indicate that invasive species can cause more severe impacts structurally simpler sites, suggesting that the successful invasion can be determined by the interaction between the invasiveness and invasiveness.