Digital Mapping applied to Biological Diversity on Ilha Grande

The analysis of the factors that structure and sustain biodiversity, as well as ecological processes, is fundamental for the conservation and management of natural resources. Ilha Grande, Angra dos Reis-RJ, provides to this day an excellent opportunity to study biodiversity, and the information obtained should contribute to local management and the general conservation of the Atlantic Forest. This project had collaboration/cooperation in the area of ​​Cartography and was coordinated by prof. Dr. Helena Bergalo (UERJ).

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The oldest record of human occupation of Ilha Grande is that of a sambaqui dating back to 960 years BC. The sambaqui population began a cycle of changing the landscape, and the change to indigenous groups brought as its main geoecological change the appearance of agriculture made with the use of fire, which would be taken over by the caiçaras.

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In addition to the occupation by caiçaras, many sugar cane, cocoa and coffee farms existed in the area. This economic cycle was based on the massive exploitation of forest resources. The low floristic diversity and secondary character in some parts of the island had its genesis in this type of exploration and in the caiçara fields. The island is today protected by three Conservation Units and UERJ manages the Vila Dois Rios area.

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The research carried out shows a great biological wealth that is still preserved. However, much of the knowledge is concentrated around the villages of Dois Rios and Abraão. Furthermore, there is little research being developed that has a multidisciplinary character. This project aims to establish and map permanent plots in three sample sites on Ilha Grande, which will allow the development of integrated studies and provide information on the appropriate use of the territory to the managers of the Conservation Units. The RAPELD plot method (Rapid Assessment Program, created by William E. Magnusson and collaborators in 2005) was used, which allowed biological communities to be sampled in large sample areas and at the same time minimize the variation in abiotic factors that affect such communities. The hypotheses to be tested are that there is biotic complementarity between the sampling sites and that biological groups respond to a structuring process.