Análise de populações de Sterculia apetala em diferentes cenários de manejo da paisagem e sua influência no oferecimento futuro de habitat reprodutivo Anodorhynchus hyacintinus no Pantanal

Abstract

Anodorhynchus hyacinthinus is a species of bird listed as threatened with extinction mainly by the destruction of its habitat by burning and deforestation. In the Pantanal, the breeding of this bird couples are demanding in terms of breeding habitat, nesting in 95% of cases in the trunk of Sterculia apetala. The reduction in the availability of nests by the loss of mature trees with natural cavities or large enough for their excavation can result in low rates of recruitment and gradual reduction of population size of this bird. In this sense, the effort to conserve A. hyacinthinus in the Pantanal should also focus on maintaining populations of S. apetala, evaluating the effect of differently on management conditions on the landscape structure and population dynamics of this tree. The study was conducted in three scenarios of land management in the Pantanal, namely: Reserve a conservation mode in PRNP, Traditional, area where the cattle industry is developed with the animals at low density in native prairies, and finally Braquiária environment where the forest has been replaced by Brachiaria spp., remaining trees in the original vegetation. All areas were situated in the sub-region Nhecolândia, Pantanal, Corumbá, MS. The results show that the probability of reproduction of S. apetala is significantly influenced by the diameter at breast height (DBH) and it is estimated that the mature trees two producing viable seeds per square meter of canopy. The vigor of germination and seedlings produced by seeds of trees of S. apetala isolated in Brachiaria spp. pasture were significantly lower than that observed for seed germination and seedling trees of S. apetala entered the forest environment. The linear models of survival and mortality developed for populations of S. apetala study showed that deforestation coupled with the presence of cattle, as in scenario Braquiária alters the population dynamics of the tree, probably compromising the viability of the population. This is the removal of the forest, the seedling herbivory and trampling by cattle and the increased exposure of mature trees remaining to gusts, as the scenario Braquiária, greatly increase the mortality of individuals of S. apetala. A total of 27 bird species were recorded using the adult trees of S. apetala as breeding habitat. There is a process of ecological succession of birds that occupy the cavities in the trunks of this tree. The removal of trees of S. apetala affect fertility rates by more than a dozen species of birds in the Pantanal. In the case of A. hyacinthinus one should promote the management of the Pantanal landscape so that the populations of S. apetala not have their structure and population dynamics compromised by the practices adopted by economic activity, in this case, the cattle industry. The production of cattle in the traditional scenario stands out as being an economic activity with potential to generate wealth for the landowner, keeping the structure and population dynamics of S. apetala able to provide breeding habitat for A. hyacinthinus long term in the Pantanal. Some recommendations on program to encourage the production of cattle under the traditional model of production and creation of norms are made.