Conservation & Environmental Matters



From: Phillip Owen <owen@soft.co.za>
Date: Tue, 16 Aug 2005 10:03:36 +0200
To: <sawac@geasphere.co.za>
Subject: Timber Plantations give Forests a bad name...

GEASPHERE
www.geasphere.co.za

Note all the confusion which results from calling

'Industrial Timber Plantations 'Forests'...

Index of Media Coverage

“From The Mountain To The Tap: How Land Use And Water Management Can
Work For The Rural Poor”

wire
Reuters

print
The Daily Telegraph
The Economist
The Guardian

online
NewScientist.com

'Myth' that forests improve water flows - study
28 Jul 2005 23:01:38 GMT
http://www.alertnet.org/thenews/newsdesk/L28675540.htm
http://today.reuters.co.uk/news/newsArticle.aspx?type=topNews&storyID=20
05-07-28T230909Z_01_DIT883286_RTRUKOC_0_ENVIRONMENT-TREES.xml
http://www.planetark.com/dailynewsstory.cfm/newsid/31824/story.htm
Source: Reuters
By Alister Doyle, Environment Correspondent

OSLO, July 29 (Reuters) - Many countries are wasting millions of dollars
planting trees because of myths that forests always help improve water
flows and offset erosion, a British-led study said on Friday.

Many trees, especially fast-growing species like pines and eucalyptus
favoured by the paper industry, suck more water from the ground than
other crops, it said. The water transpires from the leaves and so the
trees dry out the land.

"Trees on the whole are not a good thing in dry areas if you want to
manage water resources," said John Palmer, manager of the tropical
Forestry Research Programme run by the British Department for
International Development.

"When it comes to wet areas, trees may be beneficial or no worse than
pasture and crops," he told Reuters of the study of plantings in India,
Costa Rica, South Africa and Tanzania in a four-year project led by
British and Dutch researchers.

Forests have many other benefits -- ranging from habitats for birds,
insects or animals to human sources of building materials and firewood.

But the report said it was a myth that forests acted as sponges that
soak up rain, releasing it throughout the year and ensuring more regular
flows in rivers. Instead, trees' deep roots often aggravate water
shortages in dry seasons.

It also said it was wrong to believe forests attracted more clouds and
rainfall or that tree roots helped slow erosion more those of short
plants. It said the myths had been anchored in cultural history since at
least the 17th century.

PANAMA CANAL

"We don't want to be seen as against forests or trees," said Ian Calder,
a lead researcher who is director of the Centre for Land Use and Water
Resources Research at England's University of Newcastle.

"But there is a need to be careful when you plant forests in the belief
you are promoting water resources," he said. "We need policies based
more on scientific evidence. Hundreds of millions of dollars are being
spent, if not billions."

The report said Panama was seeking hundreds of millions of dollars from
the World Bank to back a project to plant trees on the apparently
mistaken belief that it would attract more rainfall to help feed the
Panama Canal.

Other countries from China to Mexico also had costly afforestation
schemes at least partly based on misconceptions about water.

In the Indian states of Himachal Pradesh and Madhya Pradesh, the study
said conversion of agricultural land to forests had damaged water
supplies, cutting flows by 16-26 percent.

Availability of fresh water is a constant problem.

The World Commission on Water has estimated that demand for water will
increase by about 50 percent in the next 30 years and that around four
billion people, or about half of the world's population in 2025, will
have problems with supplies.

The study said trees often showed the "clothes line" effect.

Just as wet clothes dry quicker if hung out rather than left lying on
the ground, the enormous combined surface of trees' leaves combined with
their deep roots meant they transpired more water into the air than
other crops, it said