Ecologia de paisagens aplicada à alocação de Reservas Legais no Estado da Bahia: conceitos essenciais para uma tomada de decisão assertiva

Abstract

The history of the biodiversity and the conservation status of the Caatinga, the Cerrado and the Atlantic Forest show that these are rich regions, with a high number of endemisms; however, all of these systems have been undergoing cummulative impacts due to conversion of natural landscapes into agricultural land uses. This indicates the supreme importance of the State in creating directives and instruments to guide the activities and expansion of private activities. According to the Brazilian New Forest Code (Federal Law nº 12.651, of 25 May 2012), Legal Reserves (LRs) consist of areas, located within a rural property, whose function is to aid in the conservation and rehabilitation of ecological processes and of biodiversity, ensuring shelter and protection of the native fauna and flora as well as the sustainable use of natural resources. Notwithstanding the existence of different legal sources establishing the obligatoriness and creating instruments for forest management actions, generally with the goal of maintaining natural resources, there have been limited efforts related to the technical parameterization of the activities developed by the officers responsible for allocating the LRs. Especially noticeable is the lack of a clear link between the scientific studies in Landscape Ecology and directives for LR definition. Conversely, there has been much scientific research on subjects such as habitat loss and fragmentation, connectivity, edge effects, matrix influence, landscape genetics, metapopulations and many others, which may greatly complicate the work of those who need to use this knowledge to make executive decisions. In consonance with the increase in technical and juridical complexity of this subject, there is also an increase in the difficulty of creating procedures parameterizing LR allocation. To aid in breaching this gap, our objective here was to compile a set of relevant Landscape Ecology studies in a way that will be useful for the professionals responsible for delimiting LRs area in rural properties. For this, we selected scientific papers that we considered important for this subject and summarized their findings, theories and reccomendations, thus producing a material that may provide a conceptual basis relevant for these analyses. We selected key papers for each of several Landscape Ecology topics which we consider important for this issue, namely: Connectivity; Area Effects; Edge Effets; Matrix Effects; Habitat Quantity. As a result, we highlighted several concepts relevant to this subject. We firstly highlight the need to abandon the simplistic and dichotomic view of the landscape (as habitat VS matrix areas). We also identified sufficient theoretical and empirical evidence to show the negative effects of habitat loss and fragmentation, as well as of the creation of edges. In addition, we verified the importance of establishing criteria for the definition of prioritary areas, which would enable the assertive use of the resources destined for conservation. Based on this information, we conclude that new studies are needed to compile the existant knowledge, resulting in working methods with sufficient details to bring security to decision making in a feasible manner.