The climate of the study area is described as a humid subtropical climate without a defined dry season (Cfa climate, according to the Köppen classification), with mean annual temperature of 19.3\(^\circ\)C, and mean annual precipitation of 1708 mm well distributed along the year \cite{Maluf2000}.
The relief varies from plain to mountainous, with slope gradients ranging from 0 to more than 100%, and elevation ranging from 139 to 475 m above sea level \cite{Samuel-RosaEtAl2013}.
The study area has a complex geology with three superimposed geologic formations \cite{Brasil1980, MacielFilho1990, Sartori2009}. At elevations above \(\approx\)350 m we find the Superior Sequence of the Serra Geral Formation, which is composed of acid igneous rocks (rhyolite-rhyodacite). At elevations between \(\approx\)200 m and \(\approx\)350 m, we find the Inferior Sequence of the Serra Geral Formation. Different from the superior counterpart, the inferior sequence is composed of intermediate to basic igneous rocks (basalt-andesite).
The Serra Geral Formation also has intertrappean consolidated sediments composed of the same aeolian sandstone that compose the underlying Botucatu Formation. At elevations bellow \(\approx\)200 m we find the Caturrita Formation, which is composed of consolidated sedimentary rocks, mainly fluvial sandstones.
There also are small colluvial deposits located in lower and concave areas. These colluvial deposits are composed of materials originated from one, two or all three geologic formations \cite{SamuelRosa2012}. Finally, close to drainage channels, we can find recent fluvial deposits with heterogeneous composition \cite{SamuelRosa2012}.
Land use is diverse and underwent significant changes during the last and first decades of the 20th and 21st centuries, respectively. Large areas of agriculture and animal husbandry have been abandoned due to rural exodus.
Nowadays native forests (original or not) cover more than half of the area. The other areas are occupied with human activities such as animal husbandry (extensive grazing), crop agriculture (fallow rainfed arable cultivation and commercial irrigated cultivation), plantation forestry, settlement (residential, transport and recreational use) and water reservoirs \cite{SamuelRosaEtAl2011a}.
The study area has a high pedologic complexity \cite{MiguelEtAl2012}. The soil is relatively young or presents little or no profile development or is extremely gravelly in 72% of the study area. The seasonal water table or stagnating water appear to influence the soil properties in only 3% of the study area. A clay-enriched subsoil can be found in about 25% of the study area.