The Brazilian government has announced that it plans to undertake the huge task of recording an inventory of the trees in the Amazon rainforest.
The Forestry Ministry said the census would take four years to complete, and would provide detailed data on tree species, soils and biodiversity in the world's largest rainforest.
The last exhaustive survey was carried out more than 30 years ago.
In that time the rainforest has become increasingly threatened by logging.
The Brazilian government made a commitment in 2009 to reduce deforestation in the Amazon by 80% by the year 2020.
According to the government, in 2012 the destruction of the Amazon rainforest reached its lowest level since monitoring began more than two decades ago.
But ministers said they would be able to act more effectively if they had more accurate data.
"We are going to come to know the rainforest from within," Forestry Minister Antonio Carlos Hummel said announcing the inventory.
Environment Minister Izabella Teixeira said it would help the government to formulate environmental policies.
"In international debates about climate change, for example, we will know how much forest we have and what state it is in (...), we'll discover species, and gain knowledge about species becoming extinct, as well as information about the distribution of the forest and its potential economic use", Ms Teixeira said.
Brazil's national development bank said it would contribute $33m to the project.
The last detailed survey of the Brazilian Amazon was carried out in the 1970s, and its results published in 1983.
Forestry Minister Hummel said partial results would be published yearly, as it progressed.