Prince Harry will visit the Atlantic Rainforest that surrounds the city of San Paulo today and learn about efforts to preserve the eco system as he tours Brazil.
The forest has been described as an extraordinary cultural and historical resource with hundreds of trees and thousands of plant species.
An initiative led by the Brazilian government is trying to re-house some communities that live in the area to help protect the rainforest and allow new saplings to be planted.
Harry will meet villagers during his visit and join them them in planting trees.
Later he will tour a community centre which supports underprivileged children and adults, and join some of the youngsters in a game of football.
The final engagement of the day will be the traditional Queen's birthday party - celebrating the monarch's official anniversary - at the Brazilian British Centre in Pinheiros, Sao Paulo.
Harry will mingle with the guests, who will number around 400 and represent business, government, education and the arts, and deliver a short speech.
The centre is also the venue for a house promoting the Great campaign, an initiative that aims to promote the UK across the globe on the back of London 2012 and the Queen's Diamond Jubilee.
The house will feature an exhibition of Beatles memorabilia which Harry will see.