"Biodiversity is essential to life and this is the only international global convention singularly focused on that precious resource -- on the need to conserve biodiversity," Leape said in a telephone interview.

"There is no question that the long-term sustainability of the world's food supply depends in no small part on how we take care of the world's biodiversity," he said, noting that all crops from rice to wheat depend on wild stocks.

A recent surge in food prices, due partly to booming demand in fast-growing economies such as China and India, has sparked concern among politicians all over the world.

UN experts warn the planet is facing the worst spate of extinctions since the dinosaurs died out 65 million years ago. Some estimates say a species vanishes every 20 minutes, due mainly to human activity and greenhouse gas emissions.

About 4,000 experts and officials aim to agree at the Bonn meeting on how to slow the rate of loss of plants and animals. A United Nations summit in 2002 set a goal of slowing the rate of biodiversity loss by 2010 but experts bemoan a lack of progress.

"We're not now on track as a planet to meet that target," said Leape. "There is no question that there needs to be a clarion call at the conference to governments, not just environment ministries, to step up their commitments."

He said measures to conserve life had to be an integral part of policy across government and there was a need for national leaders, including German Chancellor Angela Merkel, to make a stand to get the issue higher on the global agenda.

Leape said countries including Brazil, Costa Rica and Borneo had taken significant steps to improve conservation.

SUPPORT

"The industrialised world needs to be supporting the global effort to achieve these targets, not just in their own territories where a lot of biodiversity has already been lost, but also globally," he said.

He wants donor governments to make financial commitments to specific programmes and pointed to two areas in particular.

Governments had to renew commitments already made to create effective "protected area" systems to reduce biodiversity loss. The Convention has a goal to ensure that at least 10 percent of each of the world's ecological areas are effectively conserved.

Secondly, Leape wants the conference to commit itself to zero net deforestation by 2020.

"Deforestation is a very important cause of climate change -- something like 20 percent of global (greenhouse gas) emissions come from deforestation so it is very important we find a way of getting to grips with that challenge," he said.

"This cannot be a place where people talk and wring their hands, we have to have a candid recognition that we are behind and that we need to get going," said Leape.