Dataset: spatial variables for describing and mapping ecotone forests associated to the Maracá Island region, State of Roraima, northern Brazilian Amazon
The dataset provides information on spatial variables (altitude, slope, drainage distance, Normalized Difference Vegetation Index - NDVI) that are useful for describing and mapping the ecotone forest zones that occur on the Maracá Island and its surroundings, State of Roraima, northern Brazilian Amazon. The study area is ~450,000 ha, with its geographic center located in Maracá Island. The altitude, slope and drainage distance maps are derived from the TOPODATA Project (http://www.dsr.inpe.br/topodata/). The NDVI (Normalized Difference Vegetation Index) map was obtained from Landsat TM5 images: (i) orbit 232: points 57 (03/20/2007) and 58 (03/04/2007) and (ii) orbit 233: points 57 and 58 (11/03/2007). All maps were produced in a raster format with 30 m of spatial resolution and designed for UTM / Zone 20 N, WGS 84, using the ArcGis 10.0 software (http://www.esri.com/software/arcgis/index.html; licensed by Federal University of Roraima - UFRR). The maps were used to extract samples (pixel values) of each variable (altitude, slope, drainage distance, NDVI) from 129 permanent plots (50 mx 10 m; 6.45 ha) dispersed in the six East-West walking trails from the research grid of the Biodiversity Research Program (PPBio) (see Santos et al., 2020 - https://data.mendeley.com/datasets/2j354jtddx/2). The dataset consists of three files: (i) study_site - a figure indicating the location of the study area; (ii) maps - altitude (m), slope (°), drainage distance (m), NDVI (-1: 1); (iii) environmental_variables - altitude (m), slope (°), drainage_distance (m) and NDVI (-1: 1) related to the 129 permanent plots used in the dataset. The current dataset was supported by the projects (i) SavFloRR - Ecologia e manejo dos recursos naturais de ecossistemas de savanas e florestas de Roraima (PPI INPA 015/122), and (ii) Crescimento e mortalidade de árvores em florestas ecotonais de Roraima: efeito das condicionantes ambientais e da variabilidade climática (Proc. CNPq n. 403591 / 2016-3). The Coordination for the Improvement of Higher Education Personnel (CAPES) supported E.H.S. The PELD Program provide a scholarship to W.R.S. (CNPq / CAPES / FAPs / BC-Fundo Newton; Proc. N. 441575 / 2016-1). The National Council for Scientific and Technological Development (CNPq) provided a grant to R.I. Barbosa (CNPq 304204 / 2015-3). The Chico Mendes Institute for Biodiversity Conservation (ICMBio) authorized the study (SISBIO nº 52071).