The remnants of restinga habitats in the brazilian Atlantic Forest of Rio de Janeiro state, Brazil: habitat loss and risk of disappearance

Abstract

Abstract"Restingas" (herbaceous/shrubby coastal sand-dune habitats) used to cover most of Rio de Janeiro State coast, and have suffered extensive degradation over the last five centuries. Using satellite images and field work, we identified the remaining restingas in the State, recording the factors that might cause their degradation. We used two mosaics of Landsat 7 scenes (spatial resolution 15 and 30 m) to map and evaluate preliminarly the remaining areas and conservation status. Each remnant area was checked in the field, degraded areas within it were mapped and subtracted from the remnants. We identified 21 restinga remnants totalling 105,285 ha. The largest and smallest restinga remnants were Jurubatiba (25,141 ha) and Itaipu (23 ha), respectively. We identified 14 causes of degradation. The most important were vegetation removal for housing developments, establishment of exotic plant species, change of original substrate, and selective removal of species of economic importance for the horticultural industry. All restingas had disturbed parts under strong pressure due to human activities. Due to intense habitat loss, and occurrence of endemic/threatened vertebrate species in restinga habitats, we strongly indicate the implementation of new conservation units to protect these fragile remnants. This habitat is steadily decreasing and most remnants lack legal protection. Therefore, under the current human pressure most of this unique habitat is likely to be lost from the State within the next few years.Keywords: landscape ecology, conservation, restinga remnants, habitat disturbances, extinction. Os remanescentes dos hábitats de restinga na Floresta Atlântica do estado do Rio deJaneiro, Brasil: perda de hábitat e risco de desaparecimento ResumoAs restingas, que são hábitats de dunas e planícies arenosas cobertas por vegetação herbáceo-arbustiva e que ocorrem na costa do Brasil, no passado cobriam uma grande extensão da costa do Estado do Rio de Janeiro, mas têm sofrido uma extensiva degradação ao longo dos últimos cinco séculos. Utilizando imagens de satélite e mensurações no campo, identificamos os remanescentes de restinga no estado, registrando os fatores que causam sua degradação. Nós utilizamos dois mosaicos de cenas Landsat 7 ( resolução espacial de 15m e 30m) para localização e avaliação preliminar do estado de conservação dos remanescentes. Cada remanescente de restinga foi analisado no campo, sendo as áreas degradadas no interior da restinga mapeadas mais detalhadamente e subtraídas da área total do remanescente. Identificamos 21 áreas remanescentes de restinga, totalizando 105,285ha. O maior e menor remanescente de restinga foram Jurubatiba (25,141ha) e Itaipu (23ha), respectivamente. Identificamos 14 fontes de degradação, sendo as mais importantes delas: a remoção da vegetação para desenvolvimento imobiliário, o estabelecimento de espécies vegetais exóticas, a alteração do substrato original e a coleta seletiva de espécies vegetais de interesse paisagístico. Todas as áre-as de restinga apresentaram...

Orchidaceae of the Grumari restinga: floristic and similarity among restingas in Rio de Janeiro state, Brazil

“…1) and occupies approximately 951 ha. The Grumari restinga is one of the smallest restinga fragments remaining in the state (Rocha et al 2007), and despite being fully inserted into the Grumari Environmental Protection Area (APA Grumari), it has been severely disturbed by the expansion of farms specializing in ornamental plant production. The Grumari restinga has six vegetation formations: halophilous, psammophilous, post-beach, open shrub, closed shrub, and restinga forest.…”

Reproductive biology of a bromeligenous frog endemic to the Atlantic Forest: Aparasphenodon arapapa Pimenta, Napoli and Haddad, 2009 (Anura: Hylidae)

“…Aparasphenodon arapapa is an endemic species from the Atlantic Forest, with a specific and rare reproductive mode and its populations and conservation status deserve attention. Additionally, because of their dwelling in bromeliads, anuran species are equally vulnerable to factors that affect bromeliad conservation, such as land speculation on the coastal region of Brazil (Rocha et al 2007). …”

Hippeastrum species in areas of restinga in the state of Rio de Janeiro, Brazil: pollen characters

“…Although restinga habitats were once distributed along most of the coastline of the state of Rio de Janeiro, they have been diminishing at an alarming rate (Rocha et al 2007) due to the removal of native vegetation for human occupation, the replacement of substrates, the displacement of native vegetation by exotic plant species and the selective extraction of plants with economic value, such as bromeliads, orchids and clusias (Rocha et al 2007).…”