Responsible by the preservation of an only dune ecosystem, fens and restingas, the National Park of Sheets is divided by the mouth of the river piriá, where the transistion of two distinct areas occurs: the west predominates them laughs e, the east, the arenaceous formations that form the calls sheets of the maranhense coast.

You laugh them are deep clipping coasts, where the sea is flat and the slimy beaches, with manguezais, dunes, restingas and small falésias, while the sheets corresponding to a dune series that if draws out since the Golfão Maranhense until the estuary of the River Parnaíba.

In its totality, the ground of the park is formed by recent, corporate deposits aluvionares of gravels, sands and argilas. The dunes, fixed or mobile, that occur   in the coast, advance in direction to the continent until a 50 distance of km of the coast. Had to the represamento of the rivers for the tides, all area badly is drained and with high text of you leave.

In the tip the northwest of the park, where they are the manguezais, the vegetation is formed by the vermelho(Rhizophora fen mangle), that it can reach up to twelve meters of height, fen-white (racemosa Laguncularia) and fens-siriuba (tomentosa Avicenia, nitida Avicenua).

In beaches and dunes, under the continuous effect of the water and the marine winds, the vegetation has peculiar aspect, being distinguished enters the species the campim-da-sand (it would redeem maritime), carrapicho-da-beach or thorn-of-rosette (Acicarpha spathulata) and pimenteira (curassavica Cordia).

Already in restinga citizens occur species not directly ace tides, but still under influence of the ground arenaceous and the proximity of the ocean. They are found there liana-of-milk (Oxypetalum sp), orquídea-da-restinga (Epidendrum ellipticum), grass-of-rattlesnake (Crotallaria striata), sumaré-da-sand (Cyrtopodium sp), araticum (coriacea Annona), janaúba (Plumieria sp), onion-da-restinga (Clusia lanceolata) and mangabeira (speciosa Hancornia).

In the periods of position, diverse species of turtle-navies look beaches of the park, being distinguished enter they it turtle-green (Chelonia mydas), turtle-common (olivacea Lepiduchelys), turtle-of-gold (couriacea Dermochelys).

The birds, mainly the migratory ones, use the region as abutment in its trips, being in this in case that the trinca-réis-boreal one (Sterna hirundo), a regular visitor when it is not in the reproductive period, and the small blowpipe-rasteirinho (Calidris pissila), originating the Arctic. Of February the April is the time of the marrecas-of-wing-blue one (Anas discors) to visit the park, deriving of the United States.

In the fens, beyond innumerable species of fish, crustaceans and clams, jacaretingas can be observed (Caiman crocodilus), that they are fed preferential of fish. E, between the mamiferos, has units of deer-mateiro (mazama American) and paca (paca Agouti).

FICHE TECHNIQUE

Date of creation : 2 of June of 1981, for the federal decree nº 86060.
Localization : Maranhão, enclosing the municipios of Barreirinha and Primeira Cross.
Area : 155000 hectares.
Perimeter : 270 km.
Climate : tropical, of equatorial, hot zone half-humid, with four the five dry months.
Temperatures : annual average of 26°C, absolute principle of 36°C and absolute minim of 16°C.
Rains : between 1500 and 1750mm annual.
Relief : plan

Source. IBAMA. NATIONAL   PARKS