In general, Caatinga is located on crystalline or sedimentary depressions,
whose continuity is broken by isolated plateaus distributed in mosaic fashion.
Different from the Cerrado,
the Caatinga soils contain sufficient quantity of the basic minerals needed by
the plants. The biggest problem is really the uncertainty and the low quantity of rain
during the drought period (most rivers run dry in summer). A well planned irrigation
would transform the Caatinga almost into a garden.
Three different strata make up the Caatinga: trees (8 to 12 meters high), bushes (2-5 m)
and grasses (less than 2 m). Most Caatinga plant species have a long history of
adaptation to the heat and dryness of the region. The leaves, for instance, are tiny
and numerous (to reduce heat absorption). Some plants store water, like the
cactuses;
others have very shallow roots, so that they can absorb the water near the surface;
many are spiny. Most animals have nocturnal habits
Although Caatinga’s biota is poorly known, studies so far have identified a very
diverse and distinctive set of species. The biodiversity of Caatinga is made up of at
least 1,200 species of vascular plants, at least 185 fish species, 44 lizards, 9 amphisbaenians,
47 snakes, 4 turtles, 3 crocodylia, 49 amphibians, 350 birds, and 80 mammals.
The percentage of endemics is very high among vascular plants (around 30 percent),
but somewhat lower among vertebrates (up to 10 percent).
