Influência da estrutura da paisagem sobre aspectos reprodutivos de um planta florestal

Abstract

Habitat loss and changes in the landscape structure are effects that results of the forest fragmentation and can negative affect ecological processes, as plant reproduction and pollination. We hypothesized that the landscape structure parameters (fragment area, proximity, percentage of landscape vegetation cover - native forest, coffee, sugarcane and pasture matrix, and fragment shape) and structural characteristics of plant (height stem circumference, circumference at breast height, plant height and volume of crown) and its habitat characteristics (canopy height, vertical profile, distance to the nearest individual and distance to the nearest conspecific individual) affect the flower and fruit production and number of floral visits of forest plant. We sampled 160 individuals of a forest plant, Psychotria vellosiana, in eight landscapes (1000m radius), centered each one in one fragment, with 20 individuals per fragment. And we applied a general linear model and Akaike information criterion to select the best models that explains relations among plant reproduction with i) landscape and patch parameters and ii) measurements of structural characteristics of the plants and its habitat. We found that the number of floral visits and flower and fruit production are affected by the matrix type. Furthermore the total number of floral visits is influenced by the percentage of forest concomitantly with percentage of coffee matrix. And fruit production is affected by landscape complexity, size of individual plant and degree of aggregation of the plant population. From these findings, we may conclude that landscapes characteristics are important to explain the plant reproduction. The information generated may contribute to the theoretical gap in knowledge on the influence of matrix on plants and on ecological process. In addition, they can be used in recommendations to farmers, decision makers and public policies, i.e. to inform what type of matrix should be used in fragmented landscape to help to maintain or improve the fruit production of forest plants.