Atlantic Forest gets alert system to combat deforestation

To intensify the monitoring of forest cover and contribute to the end of deforestation in the most threatened and devastated biome in Brazil, the SOS Mata Atlântica Foundation, Arcplan and MapBiomas have launched the Deforestation Alert System (SAD) for the Atlantic Forest, a new tool to monitor and disseminate information about deforestation in the region. 

The system allows deforestation in areas starting from 0.3 hectare (ha) to be quickly identified and reported, monitored with the use of high-resolution satellite images. In addition, the new system generates monthly alerts, an agility that will allow support in decision making, both for environmental enforcement agencies (IBAMA, state public ministries and secretariats, environmental agencies and police, among others), and for entities that have mandatory or voluntary policies for purchasing products or financing productive chains with zero deforestation (such as banks, traders, supermarkets, and the food, wood, cellulose, and bioenergy industries).

The first bulletin of the Atlantic Forest SAD brings together alerts collected and validated throughout the year 2021, presenting the first partial results of deforestation in the biome in the period. This is a pilot edition in which alerts were compiled for four regions: the watersheds of the Tietê River (São Paulo), the Iguaçu River (Paraná), the Jequitinhonha River (Bahia and Minas Gerais), and the Miranda and Aquidauana Rivers, in the region of the municipality of Bonito (Mato Grosso do Sul). This first edition of the bulletin had the support of the Flex Foundation. 

Knowledge Director of the SOS Mata Atlântica Foundation, Luís Fernando Guedes Pinto explains that these sites were selected for the pilot because Minas Gerais, Bahia, Paraná and São Paulo are among the champions of deforestation in the Atlantic Forest in recent years. "In these states we chose watersheds where the problem is usually more critical, mainly due to the expansion of agriculture and cattle-raising. The Tietê River basin in São Paulo is not among the most deforested regions in Brazil, but has the particularity of being a region of metropolises and large cities, where urban expansion also threatens the Atlantic Forest", he explains. Bonito (MS), in turn, was the municipality that deforested the biome the most between 2019 and 2020.

In the four basins monitored in 2021 there were 1,103 alerts totaling 6,739 ha of deforestation. Each hectare corresponds, on average, to the area of a soccer field.

The vast majority of alerts (70%) refer to losses of less than three hectares, highlighting the new profile of deforestation in the Atlantic Forest, composed of a sum of small cuts of natural forest, which imposes difficulties for inspection. The Iguaçu basin (PR and SC) was the champion in number of alerts with this profile: 423.

According to Guedes Pinto, the new data confirm that, even though the Atlantic Forest Law is in force, deforestation is still a major problem in the biome. "We continue to lose old and mature forests, but we increasingly observe the cutting of young forests that are regenerating. This vegetation plays a very important role in connecting the older forest remnants and providing ecosystem services, such as water conservation, but many of these areas in regeneration are cut down before the vegetation reaches a more mature stage, when they can accumulate more carbon and shelter greater biodiversity. That's why the conservation of the Atlantic Forest depends on a strategy that combines restoration, planting of native trees and combating deforestation," he says.

As of the next Atlantic Forest DSS report, the entire biome will be monitored following the boundaries of the Atlantic Forest Law application map. 

All the data from the Atlantic Forest DSS will be available monthly on the MapBiomas Alerta platform and the results will be gathered in quarterly bulletins published by the SOS Mata Atlântica Foundation at:   


The average size of each deforested area in the Atlantic Forest has been decreasing over the years. Losses of less than three hectares and in young native forests are now common, conditions different from those traditionally monitored by the Atlas of Forest Remnants in the Atlantic Forest - a collaboration between INPE (National Institute for Space Research) and SOS Mata Atlântica that has become a reference by monitoring forest cover and deforestation in the biome year after year since 1989.

Complementing and improving the annual monitoring carried out by the Atlas, the Atlantic Forest SAD uses an automated identification based on the comparison between images with 10-meter resolution registered by Sentinel 2 satellites. "This method is able to detect evidence of deforestation from 0.3 hectare, which are validated, refined and audited individually in high-resolution images and cross-referenced with public information, including properties from the Rural Environmental Registry (CAR) and deforestation embargos and authorizations from SINAFLOR/IBAMA, to be made available on MapBiomas Alerta, a single, open and transparent platform that monitors the entire Brazilian territory," says Marcos Rosa, director of Arcplan. 

For Tasso Azevedo, general coordinator of MapBiomas, this approach "provides a new lens for monitoring the native vegetation of the Atlantic Forest and collaborating to put a definitive end to its deforestation, which is essential for mitigating climate change, for water and biodiversity conservation and for Brazil's prosperity. "SAD Mata Atlântica joins other alert systems of the Brazilian biomes, forming a network of civil society organizations and research entities that monitors all of Brazil's ecosystems," adds Azevedo. 

About the SOS Mata Atlântica Foundation

The SOS Mata Atlântica Foundation is a Brazilian environmental NGO whose mission is to inspire society to defend the Atlantic Forest. It works to promote public policies for the conservation of Brazil's most threatened biome by monitoring the forest, producing studies, demonstration projects, dialogue with public and private sectors, improving environmental legislation, and communicating with and engaging society.

About Arcplan

ArcPlan is a private company with more than 20 years of experience in issues related to mapping and environmental monitoring to support actions aimed at environmental conservation, sustainable use and planning. 

About MapBiomas

MapBiomas is a collaborative network, formed by NGOs, universities and technology startups, which reveals the transformations of the Brazilian territory through science, making knowledge about land use accessible in order to pursue conservation and combat climate change. It produces annual mapping of land cover and use since 1985, validates and prepares reports for each deforestation event detected in Brazil since January 2019, and monitors water surface and fire scars monthly since 1985.