Threats to the Atlantic Forest

In 1500 when the Portuguese arrived, the Atlantic Forest covered an area of 1.5 million square kilometres. But the early settlers immediately set about clearing huge areas for cycles of sugar-cane, tobacco, coffee, charcoal and cattle ranching resulted in large areas being clear felled, and selectively logging the steeper slopes for hardwoods. By the early 21st century only around 7% of the original forest remained and only an estimated 2% primary forest was still intact, making the Atlantic Forest one of the most threatened biomes in the world.

The Serra dos Órgãos mountain range of Rio de Janeiro State in which REGUA lies, is an integral part of the large Serra do Mar that runs along the south-eastern coastline of Brazil. It provides an impressive landscape of spectacular peaks, ridges, valleys and lowlands stretching from mountain summits to restinga and mangroves on the coast. Cachoeiras de Macacu lies an hour and a half from Rio de Janeiro and is the third largest municipality in the Rio de Janeiro state with an area of 957 square kilometres.

The population of 48,600 is divided between three districts, Cachoeiras de Macacu town, Papucaia and Guapiaçu and although these districts all suffered from clear-felling and timber extraction, surprisingly 45% of its land surface remains forested although much of it is re-growth. Before the arrival of the Schincariol brewery in 2002, agriculture was the most important economic activity in the region with cattle rearing and the cultivation of lowland crops such as corn, yams, cassava and okra dominating. The most recent economic growth area has been in water extraction.

Guapiaçu is the least populated of the three districts and has five rural communities; Guapiaçu (population 600), Matumbo (500), Estreito (400), St Amaro (300) and Boa Sorte (300). The district has two major water bottling plants and three more are planned, but agriculture still dominates and pesticide use is increasing as the lowland farming is becoming more mechanised and intensive.

Current threats

Since 1986 all Atlantic forests have been protected by IBAMA (the Brazilian Institute for the Environment and Renewable Resources) and the recently created Três Picos State Park should add further protection to much of the western side of the Guapiaçu valley. However in reality IBAMA and the Park rangers have huge areas to cover and very limited resources at their disposal, so threats to the land and its biodiversity still remain.


Large scale tree clearance is no longer a threat to the Atlantic Forest, but localised clearance to increase field sizes still continues. In some areas forests are destroyed by the removal of the under-storey followed by cattle grazing which inevitably leads to the death of the larger trees. The dead trees can then be felled legally. In some areas poor land management of steep slopes with the annual high rainfall has led to terrible soil erosion and land slips which present major challenges to any type of habitat restoration.


Today, one hundred and twenty million Brazilians live within the Atlantic Forest region, mostly within the cities of São Paulo and Rio de Janeiro. In such a highly populated area there will always be pressure from increased urbanisation and land-use change.

One of the greatest threats to the Atlantic Forest of the Guapiaçu valley is from the continued encroachment of small houses for use as holiday homes or weekend retreats, and farmers are often willing to sell these small plots for development to supplement their income. Once the access road to the plot is improved the land value is increased and further plots are sold, and each small house gradually extends into the neighbouring forest or makes small clearings for bananas or simple crops. There seems to be no control of these developments even within the boundaries of the Três Picos State Park.

On a much larger scale in the year 2000 a 1,000 hectare farm near Cachoeiras de Macacu was taken over by the ‘Landless People Movement’ and the new settlers set about clearing forested areas to plant crops and create pastures. The arrival of landless people in the Guapiaçu valley would be disastrous if it ever happened.

Water demand

Although water levels in the river have decreased dramatically over the years, there is still abundant water of very good quality. The Guapiaçu district already has two bottling plants with a further three planned, but the increasing demand for fresh water in Rio de Janeiro is likely to lead to further plants appearing in the valley. Uncontrolled and illegal sand extraction from the river bed is another risk to the biodiversity of the river, especially to the fish that require shallow sandy beds for spawning.


Although illegal, hunting has been a traditional pastime for some of the local villagers for many years. If REGUA is to protect the remaining mammals and make the area safe for visitors and researchers then the hunting has to be stopped. The policy of recruiting some of the most competent local hunters as rangers has proved extremely successful, but it may have had the effect of pushing the remaining hunters into neighbouring land.

REGUA rangers now rarely encounter hunters on the reserve, but any new land acquired has to be carefully cleared of any traps and campsites. Keeping cage-birds is also common in the villages, especially Double-collared Seedeater Sporophila caerulescens, Temminck’s Seedeater Sporophila falcirostris, Green-winged saltator Saltator similis, Black-throated Grosbeak Saltator fuliginosus, and Bare-throated Bellbird Procnias nudicollis.

Although now illegal, deforestation remains a major threat to the Atlantic Forest (© Alan Martin)
Small scale deforestation of Atlantic Forest (© REGUA)
Rapidly increasing urbanisation is a major cause of deforestation and one of the biggest threats to the Atlantic Forest of the Guapiaçu valley (© Alan Martin)
Evidence of hunting is commonplace outside REGUA (© REGUA)
Caged Blue-bellied Parrot (© Alan Martin)