Gradientes ambientais e delimitação das florestas subtropicais brasileiras: uma revisão sistemática.

Abstract

The use of the term “subtropical” remains inconsistent in the Brazilian scientific literature, especially in the context of forest formations associated with the Atlantic Forest. In this study, we sought to identify which Brazilian forest formations have been classified as subtropical and to characterize the environmental gradients associated with these forests. To this end, a systematic literature review was conducted in the Scopus and Web of Science databases, yielding 372 records, of which 80 studies were included after applying the eligibility criteria. Based on these studies, geographic coordinates and information on climate, elevation, precipitation, and phytophysiognomy were compiled, supplemented by standardized edaphic data. Spatial analyses were also performed using interpolation, density estimation, and environmental suitability modeling via the MaxEnt algorithm. The studies focused primarily on the states of Paraná, Santa Catarina, and Rio Grande do Sul (94%), where the humid subtropical climates Cfa and Cfb predominate. The phytophysiognomies most frequently associated with the term were the Mixed Rainforest (42%) and the Seasonal Semideciduous Forest (23.5%), both within the Atlantic Forest region. Based on the data compiled in the review, areas classified as subtropical are associated with annual mean temperatures between 12.2 and 21.6 °C, annual precipitation between 1,181 and 3,300 mm, and elevations of up to approximately 1,668 m. The results demonstrate that the term “subtropical forest,” as used in the analyzed literature, corresponds to a quantifiable environmental envelope defined by specific combinations of climatic, topographic, and phytophysiognomic attributes, and not necessarily to the official delimitation or actual distribution of a biome within Brazilian territory.