Forests for Climate Conservation
remove carbon dioxide from the air and bind it in wood,
a valuable, eco-friendly raw material.
Hence, reforestation combined with optimal forest management
could be a partial, and economically sound approach
in the struggle of slowing down global warming. The
‘Mefyque’ project (FP5, Quality of Life)
aims to develop an integrated model for forecasting
the quality of timber. The new tool should help forest
managers establish forest management goals alongside
planting and logging schemes.
Forests are not only our “green lungs”, as
the popular saying goes, but they also play a key role in
the climate of our planet. In the year 2000, 38.6 million
km2 of the terrestrial surface was covered by
forests(1). Although Europe(2)
holds only a small share of this (1 039 million km2),
it has a considerable part of the managed forests. World-wide,
forests are shrinking due to heavy logging and habitat destruction
– with the exception of Europe. More than 90 000 km2
(2.3%) of forest cover was lost annually during the years
1990-2000, whereas Europe actually increased its wooded
area by 8 630 km2.
The reforestation policy in European countries is based
mainly on economic considerations, although the climatic
role of forests is increasingly being taken into account,
too. The guideline for any forestry policy should be sustainability:
replacing each piece of logged land with re-plantation of
equivalent ecological value.
|The climatic impact
Over the years, the conjecture that human activities are
contributing to the global increase of
temperatures has been supported by more and more evidence.
Although we have to take into account the effects of a warming
phase, starting in the 18th century, it is undeniable that
the most recent years have shown unusually mild winters
and increasing rainfall across most of the Northern hemisphere,
consistent with model forecasts for human-induced global
Presumably, the decisive factor is the massive release of
carbon dioxide (CO2) from various sources, such as volcanic
activities, combustion(3) and organic
decay. It is of great importance, therefore, to study the
various kinds of carbon sinks, such as the oceans and organic
CO2 fixation. One major
contributor to carbon fixation is the tree, because of its
size and relative abundance. A hectare of immature, albeit
slow-growing forest can absorb more than 100 tonnes of carbon
each year. The annual rate of carbon fixation in trees has
been estimated as 100 million tonnes for Europe; in addition,
every year 30-50 million tonnes are stored in the form of
processed wood. This has to be compared to the annual carbon
emission rate of 900 million tonnes in Europe.
It is therefore of ecological interest to increase the global
forest coverage by reforestation. Interestingly enough,
it is not natural woods but managed forests which yield
the most wood biomass – depending on the region, modern
forestry can grow from three to ten times the volume of
wood per hectare as that of an unmanaged forest. Hence,
managed reforestation could be a partial solution to the
problem of slowing down global warming. Indeed, it has to
be done in a sustainable way, and by using the wood as far
as possible within the economy.
|Wood, the environmentally
One of the oldest materials used by man is growing in trees:
wood. About 3.5 billion cubic metres of wood are harvested
annually in the world, worth $140 billion(4).
Although half of this is being consumed as fuel, there is
still plenty of wood used for construction purposes, paper
processing or as raw material for industrial production.
Considering that wood production and processing uses only
1-4% of the energy it is storing, it is
certainly the most ecological raw material. Of every cubic
metre of wood produced, 30-40% is used to build products
conceived to last more than 25 years, and about 30% for
products of a shorter life-span(5).
Thus, the carbon-sink effect of wood is considerably prolonged.
Furthermore, wood-made products are fully recyclable.
|An integrated European
Given the importance of the forestry sector, considering
both ecological and economic impacts, an integrated approach
to improved management is essential. Forest managers have
to know in time about the needs of the timber industry,
which relies on a regular supply of wood with uniform properties.
A model for forecasting the quality of timber would be very
helpful in decision-making about planting and logging schemes.
A European group – Mefyque – has received funding
under the Fifth Framework Programme (QLK5-2000-00345) to
develop an integrated modelling framework. The aim is to
improve understanding of
the relationships between site conditions and growth, timber
quality and production, current and future scenarios of
climate change and atmospheric compositions.
The group intends to:
- Monitor existing forest sites;
- Manipulate conditions of growth;
- Analyse anatomical, biochemical and mechanical properties
- Model growth, yield and quality at a range of spatial
The integrated modelling system will enable forest managers,
the timber industry and policy-makers to decide whether
forest management should be principally for production,
conservation or amenity outputs.
(1) All figures from ‘Global
Forest Resources Assessment 2000’, FAO, 2001.
(2) Including the European part of Russia.
(3) 12 215 million tonnes of carbon dioxide for all OECD
countries in 1998.
(4) The International Timber Trade, Tim Peck, Woodhead Publ.,
(5) Prof. Arnold Frühwald, University of Hamburg, in:
Agra-Europe, 18/12/2000, p.L14/15.
Samuel Piercy Evans
Forest Research, an Executive Agency of the Forestry Commission
Tel: +44 1420 526207