APRIL 2004

Growing menace threatens Amazon

Plants need carbon dioxide in the way that animals need oxygen - but the 30% extra carbon dioxide in the last 200 years has begun to accelerate growth and change the composition of the world's biggest rainforest, according to a study published today in Nature. "The changes in Amazonian forests really jump out at you," said William Laurance of the Smithsonian Tropical Research Institute in Panama. "It's a little scary to realise that seemingly pristine forests can change so quickly and dramatically."

For two decades, researchers have studied nearly 14,000 trees in the central Amazon, scattered across a 120 square mile landscape. During the the study, most species began to grow faster. They also died faster, to be replaced more swiftly by new, young trees. But the composition of the forests, too, was beginning to change.

Alexandre Oliveira, of the University of Sao Paulo in Brazil, said that during the period of the study most trees grew faster, but at different rates, leading to a scenario of winners and losers.

Dr Oliveira said: "In general, large, fast-growing trees are winning at the expense of smaller trees that live in the forest understorey."

The scientists found that out of a total of 115 tree genera in the Amazon, 27 had changed significantly either by increasing or decreasing in growing density, a rate of change that is 14 times greater than expected if it was due to chance.

Henrique Nascimento, a Brazilian scientist with the Smithsonian Tropical Research Institute, said that the decline of smaller, shade-tolerant trees could have important implications for the overall health of the Amazon.

Dr Nascimento said: "The decline of many small trees is intriguing because they tend to be so specialised. They live in the dark interior of the forest and are the only trees that can flower and reproduce in the shade." One possible reason for the change is that rising levels of carbon dioxide - which have increased by 30 per cent in the past 200 years - could be fertilising the trees and causing them to grow faster, especially the larger species with wood that is not as dense as the shade-loving varieties.

If this proves to be the case then the changes could have an important effect on the ability of the Amazon to act as a "sink" for atmospheric carbon, an impact that could exacerbate global warming.

"There clearly are winners and losers. In general, large, fast growing trees are winning at the expense of smaller trees that live in the forest understorey," said his colleague Alexandre Oliveira of the University of Sao Paulo, Brazil.

"Sadly, this could be a signal that the forest's ecology is changing in fundamental ways," Dr Laurance said. "Tropical rainforests are renowned for having lots of highly specialised species. If you change the tree communities then other species - especially the animals that feed on and pollinate the trees - will undoubtedly change as well."

To separate the effects of global warming from other stresses, the researchers based their studies on plots of forest chosen because they had not been logged, burned, used for hunting or damaged by windstorms. The next step is to see whether such changes were mirrored in other tropical forests around the world.

"If they are, then it is likely that even the world's remotest forests are now being altered by human activities," said Thomas Lovejoy, now of the Heinz Centre for Science, Economics and Environment, who launched the research two decades ago.

"Garden of Eden" in Southern Iraq Likely to Disappear Completely in Five Years Unless Urgent Action Taken
UNEP PRESS RELEASE

UNEP Says Post-War Rehabilitation Should Include the Marshlands of Mesopotamia for the Sake of People and Wildlife

Kyoto/Nairobi, 22 March 2003 - The Marshlands of Mesopotamia, considered by some to be the Biblical location of the Garden of Eden and known as the fertile crescent, are continuing to disappear at an alarming rate.

Studies, disclosed today at the 3rd World Water Forum taking place in Kyoto, Japan, indicate that of the 10 per cent of the marshlands left, one third has disappeared in the past two years with many endangered species such as the Sacred Ibis and African darter holding on at a knife's edge.

Two years have elapsed since the United Nations Environment Programme (UNEP) drew the world's attention to the plight of the marshlands and its unique culture, the Marsh Arabs who are the 5,000 year-old heirs of the Babylonians and Sumerians.

Satellite studies, carried out by UNEP's collaborating GRID-Geneva centre and covering a period from the early 1970s to 2000, showed that 90 per cent of the marshlands, also home to rare and unique species and a spawning ground for Gulf fisheries, had disappeared.

The new studies show that a further 325 square kilometres have dried out since 2000 leaving just seven per cent of the original area. Unless urgent action is taken to reverse the trend and rehabilitate the marshlands, the entire wetland known as the Hawr Al-Hawizeh in Iraq and Hawr Al-Azim in Iran, are likely to have gone in three to five years.

Klaus Toepfer, Executive Director of UNEP who is attending the Forum, said: "As we mark World Water Day 2003, we are reminded again of the dramatic destruction of the Mesopotamian marshlands and their unique culture and wildlife over the past decade. It is an environmental catastrophe for this region and underscores the huge pressures facing wetlands and freshwater ecosystems across the world".

"We have already lost half of the world's wetlands in the last 100 years, and the continued desiccation of the Mesopotamian marshlands confirms that more decisive and concrete action is needed," he said.

Mr Topefer said he hoped that the end of hostilities in Iraq and the rehabilitation of the country would include a full assessment and action plan for the restoration of the marshes.

UNEP's Post Conflict Assessment Unit, which has successfully carried out environmental assessments and drawn up action plans for the Balkans and more recently Afghanistan and the Occupied Palestinian Territories, stood ready to assist in any project to restore the wetlands.

Mr Topefer said such an assessment needed to address all the issues which are potentially impacting on the marshes. These include extensive internal drainage programmes and dams upstream including those on the Euphrates and Tigris rivers. UNEP believes there is still a last window of opportunity to reverse wetland desiccation and achieve at least partial restoration. In the short term, an emergency release of water from reservoir dams in Iran and Iraq to simulate the seasonal flood is needed.

Iran reacted positively with a limited release of water to the wetlands in March and April 2002 flooding the northern core part.

A long-term recovery plan is however needed. This will require a holistic river basin approach based on the ultimate goal of sustaining riverine ecology and in which all Tigris-Euphrates riparian countries share the rivers' waters in a coordinated and equitable manner. An integrated catchment plan would also give priority to allocating an adequate amount of water to the wetlands, while water releases from existing dams can be timed to mimic natural flow patterns and bring the marshlands back to life.

The Mesopotamian marshlands are an integral part of the Tigris-Euphrates river basin, which is shared by Iran, Iraq, Syria and Turkey. UNEP first drew the world's attention to the demise of the largest wetland ecosystem in the Middle East Mesopotamian marshlands in May 2001 with hard evidence from satellite imagery capturing the shrinkage of the marshlands' physical extent. The UNEP study (link below) revealed that by spring 2000, a one thousand-square kilometre vestige straddling the Iran-Iraq border was all that was left of the extensive wetland complex, which originally covered an area of 15,000 - 20,000 square kilometres.

For more information, please contact: Eric Falt, UNEP Director of the Division of Communications and Public Information, on Tel: 254 2 623292, e-mail: eric.falt@unep.org or Nick Nuttall, UNEP Head of Media, on Tel: 254 2 623084 in Kyoto on 81 (0) 90 6946 3372, e-mail: nick.nuttall@unep.org