The talks in the Japanese city of Nagoya are aimed at setting new 2020 targets to protect plant and animal species, a protocol to share genetic resources between countries and companies and more funding to protect nature, especially forests.
The UN Food and Agriculture Organisation (FAO) estimates that global deforestation fell from 16 million hectares (40 million acres) per year in the 1990s to 13 million hectares per year in the past decade, with the bulk of the losses in tropical countries.
About 12% of the world's forests are designated primarily to conserve biological diversity, the FAO said in a report earlier this month.
Forests soak up large amounts of carbon dioxide, the main greenhouse gas, and help curb the pace of climate change. They are also key water catchments, help clean the air and are home to countless species.
"Our forests need immediate action," Brazil's Environment Minister Izabella Teixeira told the meeting.
Ministers are focusing on a voluntary partnership covering nearly 70 nations aimed at boosting a UN-backed scheme that seeks to reward developing countries that preserve and restore forests.
Called REDD-plus, or reduced emissions from deforestation and degradation, the scheme has attracted funding pledges from rich nations aimed at developing pilot forest preservation projects as well as ways to channel the cash in a transparent way.
But the partnership has had a troubled start, with bickering over management of the cash and procedural issues. The Nagoya meeting is meant to breathe life into the scheme ahead of major climate talks in Mexico late next month.
Ministers are due to release a statement at the end of their one-day REDD talks on Tuesday before turning their attention to trying to seal 2020 targets and a genetic-benefits sharing pact that could generate billions of dollars for poorer nations.
(EurActiv with Reuters.)