Thursday, August 9, 2007

PS 67-149: The use of network approach to evaluate the efficiency of restoration outcome: A tropical case study applied to plant-pollinator interactions

Simone B. Vosgueritchian and Silvana Buzato. Universidade de São Paulo

The assessment of forests submitted to restoration process is essential for improving restoration techniques, especially in tropical and subtropical ecosystems in which the high diversity and complexity of interaction among organisms make the restoration a challenge. The majority of interactions between plants and their flower visitors are rooted in a complex web of interactions that can be described by network attributes. We evaluated plant-flower visitor interactions by description of some network attributes in order to verify structural and functional variation between abandoned and restored pastures of the same age and similar land-use histories. The communities analyzed had few species of plants and animals in common, but showed similar nestedness and connectance. In addition, in the restored pastures the mean number of interactions per plant species was slightly higher than in abandoned ones. Besides Hymenoptera, Lepidoptera and Diptera were the core taxa showing the highest number of interaction in restored and abandoned pasture, respectively. The shift in the core taxa between networks apparently was related to the presence of distinct floral types. The similarity in the functioning of these communities is apparently related to the properties of mutualistic networks, and the real value of functional approach in the evaluation of restoration outcome must consider a look at the identity of interaction. (Grant from CAPES).