||In southern coastal area of São Paulo State, between latitudes 24°17'-24°40'S and longitudes 47°00'-47°30'W.
||Open "campo" on mountaintops, moist forests on mountainsides, "restinga" vegetation and mangrove swamps near ocean.
||High diversity and high endemism expected, at least 500-600 species; some disjuncts from Amazonia; threatened species.
||Rich in medicinals; species for fibres, timbers (especially Tabebuia cassinoides); edible species (especially Euterpe edulis); ornamentals.
||Ecological sanctuary for threatened fauna; research station; potential genetic resources; ecotourism; historical sites.
||Palm-heart gathering, logging, hunting.
||Assured with establishment of Juréia-Itatins Ecological Station.
||CPD Site SA17
The Juréia-Itatins Ecological Station (Estação Ecológica Juréia-Itatins) (EEJI) occupies portions of the municipalities Peruíbe, Itariri, Miracatu and Iguape in the valley of the Ribeira de Iguape River, 210 km south-west of the city São Paulo. The EEJI has roughly the shape of an inverted triangle 90 km wide and 45 km from north to south (Map 53). It is crossed by the Una do Prelado River, a black-water river that winds north-eastward more or less parallel to the Atlantic coast for 80 km, isolating the Serra da Juréia. To the north-east the region is delimited by the Paranapu massif, a buttress of the Serra dos Itatins.
The Serra da Juréia (which means prominent point in Tupi-Guaraní) is an inselberg connected to the rest of the mainland by a plain of alluvial sands, which formed during a post-glacial submersion by the sea. This is known as the Cananéia Transgression, which took place some 5100 years ago when the sea was c. 3 m above its present level (Por and Imperatriz-Fonseca 1984). For long periods the Una do Prelado River and its principal tributary the Cacunduva River were for much of their length turned into saltwater gulfs, which cut off the Serra da Juréia from the mainland. Evidence of this insular past includes the occurrence of "sambaquis" deposits of shells and other debris left by prehistoric indigenous populations c. 30 km inland from the estuary of the Una. The isolation brought about by the Cananéia Transgression and the fact that the forests on the flanks and top of this massif are even now separated from the body of the Atlantic forest by the alluvial plains, may be interpreted as conditions suitable for speciation.
The Serra da Juréia is a Precambrian horst. The Juréia massif covers an area of 58 km² and reaches elevations of 400-800 m. It is divided by a depression occupied by the Verde River, whose clear water and steep southern course are fed by the waterfalls of Juréia. The eastern face of the massif falls abruptly to the ocean, forming a steeply sloping coastline. The Una do Prelado River rises in the region of Banhado Grande south-west of the Serra da Juréia and is formed almost exclusively by rainwater; it is nutrient poor though rich in humic substances, with a pH of 3.7 (Por 1986; Por et al. 1984). The Una runs over a low plain (up to 4 m above sea-level) and is influenced by the tides over almost its entire course. In times of drought, seawater penetrates as far as 30 km into the estuary. The salinity of the waters of the Una and Cacunduva rivers is regulated entirely by rainfall and tides. Mangrove swamps extend as far as c. 5 km inland from the estuary.
The watercourses that arise on the Serra da Juréia contain clear nutrient-poor water with a pH of 5-6.5. There are springs in the natural campo, but most of the streams are intermittent and come from rainfall. During periods of intense rain, small waterfalls may turn into large cataracts. The hydrological wealth of the region results from two principal factors lithology and climate.
The Ribeira lowland (Baixada do Ribeira) is characterized by average annual temperatures of c. 21°-22°C and the higher elevations with c. 17°-18°C. Relative humidity is above 80% and the average annual rainfall is c. 2200 mm (Camargo, Pinto and Troppmair 1972). High rainfall is due to the influence of two air masses: the Tropical Atlantic Mass originates in the South Atlantic and is active throughout the year, directly influencing the distribution and quantity of rainfall; the Polar Atlantic Mass arises in Patagonia and is more limited in its effect but still of great importance, causing abrupt drops in temperature that may cause frost at the higher elevations (Tôha 1985).
On the tops of the mountains the climate has favoured the formation of soils, which have an average depth of 2-3 m. On the slopes, which may be as steep as 35°, the soils are shallower and in the absence of vegetation are soon eroded. In the lowlands between the mountains lie the alluvial soils that result from recent sedimentation. The nature of the mountain soils hinders the infiltration of water to deeper layers; thus the water table does not lie deep, and water surfaces as a large number of springs and watercourses.
The vegetation of the region varies according to altitude and soil. There are five main types: open campo, forest, scrub, herbaceous restinga vegetation, and mangrove (Eiten 1970).
The open "campo" vegetation, which covers the tops of the mountains at elevations over 300 m, is grass-herb-subshrub fields with scattered low to medium-tall xeromorphic shrubs.
The forest formation includes a series of evergreen tropical forest types covering the slopes and base of the mountains (Coutinho 1962). The three most important types are: (1) a moist tall forest on the seaward slope of the Serra do Mar; (2) littoral tall forest, a low-altitude forest on alluvial and lacustrine clays (and occasionally sands) of the inner part of the littoral plain; and (3) restinga forest, a low to medium-tall forest, with a composition very different from the slopes of the Serra do Mar.
The other formations that occur in the "restinga", a littoral sandy plain c. 40 km in extent (Silva and Leito-Filho 1982), are: (1) restinga closed scrub, a low to tall and very dense evergreen scrub forest; (2) restinga open scrub ("nhundu"), composed of evergreen shrubs and low twisted trees; and (3) herbaceous beach vegetation, closed to sparse evergreen grass-herb fields covering the low dunes and beaches (Hueck 1955).
The mangrove vegetation is an evergreen low forest, or low to tall and closed scrub, of Rhizophora mangle, Avicennia schaueriana, Laguncularia racemosa and Hibiscus pernambucensis, usually with distinct boundaries between it and the restinga forest.
The flora of Brazil's Atlantic Coast forest is incompletely known, with new species and even new genera being discovered. Random samples of the moist forest indicate significant endemism, which has been estimated as 53.5% among tree species (Mori et al. 1983) and 37.5% in non-arborescent families - or 74.4% including Bromeliaceae. Endemism of palms is a rather high 64%, with 49 species endemic to the Atlantic coastal forests; 11 are considered threatened. Endemism for bamboo genera has been estimated at 40.9%; the region has been a refuge for various primitive species of bambusoid grasses and some woody groups (Soderstrom and Calderón 1974). The isolation of the Atlantic forest from Amazonia took place in the late Tertiary, which explains why this region has many plant species in common with the Amazon, but also many endemics.
A Flora of the Serra da Juréia is in preparation. Preliminary results on the slope forest indicate the presence of 76 families of dicotyledons, 21 of monocotyledons and 14 of ferns and fern allies; c. 500-600 species are estimated for the region. The canopy varies in height from 20-30 m, with emergents reaching 35 m. The families most numerous in tree species are Myrtaceae (18 spp.), Leguminosae (16), Melastomataceae (10) and Annonaceae (9). The shrub layer varies in height from 2 m to 5 m, and is distinguished by many species of Rubiaceae (15), Acanthaceae (9), Piperaceae (5), Rutaceae (5) and Myrtaceae (5). The tree and shrub layers also contain a wide diversity of lianas, creepers and epiphytes. Among the epiphytes, most of the species are in Orchidaceae, Bromeliaceae, Araceae and Gesneriaceae or ferns, whereas most lianas and vines are in Compositae, Malpighiaceae and Bignoniaceae.
Results of a three-year inventory programme confirm the wealth of the flora and