GEO Brasil - UNEP

The Caatinga
The area of the Caatinga covers an area of approximately
735,000 square kilometres, about 11% of the national territory,
including part of the States of Piauí, Ceará, Rio
Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe,
Bahia and Minas Gerais. This biome is dominated by one
of the few types of vegetation whose distribution is totally
restricted to Brazil (Ferri 1979). This vegetation is mainly
constituted by small woody and herbaceous species,
many have thorns, being usually the so-called “caducifolias”,
and for cactaceas and bromeliaceous. The density,
frequency and dominance of the species are determined
by the topographical variations, type of soil and rains
(Drumond et al. 2000).
In general, the biota of the savannah has been described
as poor and with few endemic species and therefore, of
low priority for conservation. Recent studies show that
this analysis is far from being true (in Drumond et al. 2000).
The area possesses a considerable number of endemic
elements. Out of the 596 arboreal species registered, 180
are endemic (Drumond et al. 2000).
capitals Natal, Fortaleza and Teresina - the average per
capita income exceeds a minimum wage, being, in its
great majority lower than half a minimum wage (Sampaio
& Mazza 2000).
The area has been greatly modified by man’s presence.
The Northeastern soils are undergoing an intense process
of desertification due to the substitution of the natural
vegetation with culture, mostly by means of burnings
(Garda 1996 in Casteleti et al. 2000). The deforestation and
irrigated cultures are to the salinisation of the soils, one
of the most serious threats to the Caatinga. In areas such
as the “São Francisco Valley”, irrigation without appropriate
technique, worsened by the characteristics of plain
soils and intense evaporation of the water, provoked by
the strong heat, has turned the agriculture in these areas
impracticable (www.wwf.org.br). Only the presence of the
adapted vegetation of the Caatinga region has been preventing
the Brazilian Northeast from turning into an immense
desert (Garda 1996 in Drumond et al. 2000).
annex 3
Several new species of animals and endemic plants have
been described recently, indicating a very precarious zoological
and botanical knowledge.
Approximately 50% of the lands in the Caatinga are of
sedimentary origin, rich in underground waters. The rivers,
in their majority, are intermittent and the water volume,
in general, is limited, being insufficient for irrigation.
An estimated population of more than 25 million inhabitants,
with large structural problems regarding sustainability
of food production systems is settled on this biome.
The constant negative effects of the climate, as the periodic
droughts, hinder the maintenance and development
of those production systems, leading to deterioration of
the soil, depletion of the water, decrease in biodiversity
and beginning of desertification (Drumond et al. 2000).
The demographic density of the municipalities of the Caatinga
is, usually, very low. In the states of Maranhão, Minas
Gerais and Piauí it is so low that those areas were
called “Demographic Emptiness” in the recent past. In
Rio Grande do Norte, Paraíba, Pernambuco, Alagoas and
Sergipe the density is higher. The Caatinga holds the poorest
population in the Northeast and one of the poorest
populations in Brazil. In only three municipalities - the
In spite of the threats to its integrity, less than 1% of the
Caatinga is protected by restricted use conservation units
(The Nature Conservancy Association - Caatinga). In the
last 15 years of the 20 th century, approximately 40 thousand
square kilometres of the Caatinga region became
desert due to man’s interference on the environment. Steel
industries and brickyards have contributed to that process
by cutting down native vegetation for firewood production
and vegetable coal (www.wwf.org.br).
There is no concrete data for the vegetation loss rate covering
the Caatinga. Maps generated by the Radambrasil
Project (IGBE 1993) show that the area covered by agricultural
activities in the biome was 201,786 square kilometres,
which corresponds to 27.5%. A simulation of the
effects of the highways as axes of environmental alteration,
considering a width of seven kilometres as impact
area due to the highway, resulted in a modified area of
131,044 square kilometres. Combining these estimates,
the total area modified by man in that region would be
332.830 square kilometres, in other words, 45,3% of the
biome. This value places the Caatinga as one of the most
modified environments by man in Brazil, being surpassed
only by the Atlantic Forest and the Savannah (Casteleti
et al. 2000).
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