Study area
We conducted this study near Sinop, Mato Grosso, Brazil (11.8608°S,
55.5095°W; Fig. 2) at the southern edge of the Amazon forest biome. This
area is largely defined by seasonally dry evergreen tropical forest
(NT0140) at the transition zone between the Cerrado scrubland savannah
and Amazon biomes (Fig. 2). The climate is classified as neotropical
with a fairly consistent mean temperature all year-round (24-25°C), but
with great variation in mean precipitation between the dry (mean July
rainfall = 2 mm) and the wet season (mean February rainfall = 309 mm) .
The study area was nearly completely forested until the 1970s when
cattle ranching, logging, and more recently soybean agriculture began
fragmenting the once contiguous forest and promoted rapid development of
urban areas. This is consistent with patterns of deforestation across
the Brazilian Amazon where soybean monoculture is one of the primary
drivers of deforestation (Fearnside, 2017; Nepstad et al., 2006). Thus,
a mosaic of primarily soybean agriculture (that is typically
intercropped with maize), exotic pastures, and forest fragments have
replaced primary forest.