Fig 1.
Location of the study region (upper left corner) and zoom of our study area showing the spatial distribution of the caves included in our analyses over an elevation layer.
Caves are colored according to their relevance category (N = 843 caves), and the Carajás National Forest is shown in green. The digital elevation raster (SRTM, 1 arc-second) was obtained from USGS Earth Explorer, the National Forest shapefile from ICMBIO, and the South America shapefile from Thematicmapping.org. All layers are copyright-free.
Fig 2.
Spatial autocorrelation of species richness, presence of rare troglobites, presence of troglobites, and presence of resident bat populations, across different spatial scales.
While the solid lines show the value of estimates (Moran's I and Single Color Statistic), the gray area depict 95% confidence intervals. Dashed lines represent expected values under a null model of no spatial autocorrelation.
Fig 3.
A: Relationship between species richness and cave area in caves with guano (triangles) and caves without guano (circles). B: Species richness in caves with and without water reservoirs (sample sizes are given in parentheses). Species richness is detrended for the effect of other predictors.
Table 1.
Summary of the best models describing cave biodiversity.
Table 2.
Parameter estimates and hypothesis tests for the best models describing cave biodiversity.
Fig 4.
Relevance classification of caves with different numbers of biodiversity indicators (high species richness, presence of rare troglobites, presence of troglobites, and presence of resident bat populations).
While variation in cave area is represented in the X axis, density plots are shown besides each variable (the vertical dashed line represents the median area of caves containing three or more biodiversity indicators). The relevance categories shown are based on biological attributes only, following the current Brazilian legislation.