Tietê Forests

Restoration approaches:

  • Assisted Natural Regeneration (ANR)
  • Framework Species Approach (FSA)


  • Protect water resources and improve the water supply for local communities, transitioning the region away from the use of herbicides that can have long-term damaging effects on biodiversity, water bodies and humans.
  • Increase forest cover by restoring riparian (riverbank) forests, establishing wildlife corridors to boost biodiversity.
  • Scale up from four to around 15 municipalities over time. The first phase aims to restore 2000 hectares on AES Brasil landholdings (representing around 4 000 000 trees). The total landscape at this side of the Tietê watershed could eventually encompass around 15 municipalities.

Discover more on WeForest’s website

Why is intervention needed?

Brazil’s Atlantic Forest stretches along the Atlantic coast and inland as far as Paraguay. It is thought to have covered as much as 1 500 000 km2, but today at least 72% has been cleared, mainly for agriculture. Most of the remaining forest patches are small and isolated, and many plant and animal species are threatened with extinction. Alongside the Tietê river, significant deforestation has taken place.

The Brazilian Forest Code aims to protect rivers, soils and forests on private lands. Unfortunately, the code is not always adhered to, often because of a lack of financial and technical capacity. Today, the land that officially falls under this law and that is not forested – in other words, that needs to be restored – amounts to around 19 million hectares.

Establishing wildlife corridors

AES Brasil is already restoring sites that the Brazilian Forest Code requires to be placed under restoration. The Tietê Forests project will focus on additional sites where this is not obligatory by law, actively planting native vegetation, enhancing a wildlife corridor and helping protect the river basin from erosion.

The region supports more than 100 mammal species, including the puma (Puma concolor) and the maned wolf (Chrysocyon brachyurus), of which 6 are threatened. It’s also home to over 400 bird species, of which 18 are threatened, more than 40 amphibian species, and several endangered or vulnerable tree species.

A fully green approach

In Brazil, invasive grasses and leaf-cutter ants are two major obstacles to forest restoration, and they are usually controlled with herbicides and insecticides. While it is possible to control them with a fully organic approach, it is extremely laborious and difficult to do on a large scale. With its aim to protect the water resources of one the largest rivers in the state of São Paulo, the Tietê Forests project serves as the perfect opportunity to experiment with ways to reduce or eliminate the use of herbicides and pesticides by testing different spatial arrangements or species combinations, and developing best practices.

To do this, the project adopts a three-pronged approach:

  1. The removal of grass prior to planting will be carried out mechanically by mowing.
  2. Green manure – Guandu or pigeonpea (Cajanus cajan) – will be used in between native vegetation as an extra contribution to the fast-growing and large-crowned plants that shade and suppress invasive grasses, accelerating the growth of all native species.
  3. The biomass of both the mown grass and the green manure will be used as mulch during tree planting, also to stop invasive grasses growing again.