Issue 5: Climate Change Mitigation, Forest Management and Effects on Biological Diversity

Full text

-1-
Contents
Foreword ................................................................1
Executive summary...............................................2
1. Introduction ................................................2
2. Key factors of forest
biological diversity ....................................2
3. A landscape approach to
forest management for carbon
sequestration..............................................4
4. Future prospects and policy options ......8
5. Glossary.......................................................8
6. Further reading...........................................9
Technical editing: Johanna Kohl, Federal
Research and Training Centre for Forests,
Natural Hazards and Landscape (BFW)
Requests for reproduction of articles
should be addressed to the editors.
Newsletters can be downloaded from
http://www.iufro.org/science/task-forces/
http://www.iufro.org/science/task-forces/carbon/ Newsletter
No. 5 - 2007
Issue 5: Climate Change Mitigation, Forest Management and
Effects on Biological Diversity.
T-B. LARSSON1,A.BARBATI2,J.BAUHUS3,J.VAN BRUSSELEN4,
M. LINDNER4,M.MARCHETTI5,B.PETRICCIONE6,and H. PETERSSON7
1European Environment Agency, Copenhagen, Denmark
2Department of Forest Environment and Resources, University of Tuscia, Viterbo, Italy
3Institute of Silviculture, Freiburg University, Freiburg, Germany
4European Forest Institute, Joensuu, Finland
5Department of Science and Technology for the Environment and Territory, University of Molise, Pesche, Italy
6CONECOFOR Office, National Forest Service, Roma, Italy
7Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umea, Sweden
Foreword
Forests and forest management have the potential to make substantial contribu-
tions to national and global mitigation portfolios designed to reduce the rate of
carbon dioxide (CO2) increases in the global atmosphere. In developing appropriate
management strategies involving forests, managers are increasingly expected to
consider a wide range on issues and indicators, including the impacts of their
actions on the greenhouse gas balance.
The IUFRO Task Force on Forests and Carbon Sequestration was initiated in 2001
and its term renewed in 2006. Its mandate is to address issues related to the
potential role of forests in carbon sequestration and to prepare readily accessible
synthesis information, including a series of e-Notes.
The first four e-Notes have addressed the role of forests in the global carbon cycle,
the impacts of disturbance regimes on forest carbon storage, the economics of
forest management, and forest management options to increase carbon storage.
IUFRO is pleased to introduce this fifth e-Note which addresses the effects of
forest management on biodiversity. Task Force e-Notes together provide a suite of
timely, readily accessible, concise, and informative state of science summaries.
Editor:
Dr. Werner Kurz
Task Force Coordinator
Natural Resources Canada
Canadian Forest Service – Pacific Forestry Centre
Victoria, BC, Canada, wkurz@nrcan.gc.ca
The Role of Forests in Carbon Cycles,
Sequestration, and Storage
Dr. Robert Jandl
Task Force Deputy Coordinator
Research and Training Centre for Forests, Natural
Hazards and Landscape (BFW)
Vienna, Austria, robert.jandl@bfw.gv.at

Executive summary
Forest management strategies to promote long-term
storage of carbon could include mitigation of
ecosystem disturbances, such as fire and other
hazards creating carbon emissions, afforestation to
increase the area of forest land and silvicultural prac-
tices which increase carbon sequestration. A signifi-
cant part of the carbon stock of a forest ecosystem is
found in the litter and soil organic matter. Biodiversity
in soil as well as above ground should thus be consid-
ered.
The general perception of a natural forest is that this is
a biodiversity repository as well as a large carbon stock
which only needs protection. However, a main issue
both for biodiversity and carbon is that forest ecosys-
tems are naturally dynamic and subject to disturbances
and succession. Preserving late successional stages
by protection and controlling fire will increase carbon
stocks and may enhance biodiversity, but may have
negative impacts on the species that depend on earlier
successional stages.
In most of Europe, the forests are considered to be
semi-natural, reflecting the long history of human use
and forestry. One of the structural features that has
been generally reduced in managed forests is dead-
wood. Preserving deadwood, as well as promoting big
and/or older trees, is thus favourable both for carbon
stocks and biodiversity. The current trend towards
increased forest volumes is also mainly favourable,
however, the plant diversity in the understorey of
darker forests is likely to decrease. In addition,
promoting forest growth and carbon sequestration by
application of nitrogen fertilizer is highly controversial
from a biodiversity point of view. It would exacerbate
the effect of long-range air pollution (N deposition),
further increase the ‘eutrophication’ of the forest
ecosystem and favour a few nitrophilous plant species
while overall ground vegetation species diversity
decreases.
While planting is a widespread regeneration technique
in the semi-natural forests, establishment of ‘forest
plantations’, i.e. uniform stands of exotic or introduced
tree species, is under debate from a biodiversity point
of view because highly productive trees would be
used, often exotic species and/or biotechnologically
‘improved’ genotypes. The most extreme would be
genetically modified trees that even may include
genes to increase resistance to diseases or defoliating
insects. From a biodiversity viewpoint, this would be a
very risky strategy, because such genes might spread
into native populations.
1. Introduction
Forest management aimed at increasing the long-term
storage of carbon in terrestrial ecosystems is a poten-
tial climate change mitigation measure which could
also greatly impact the biological diversity of forest
ecosystems. Biological diversity, or biodiversity, is
defined within the Convention on Biological Diversity
(CBD) as ‘the variability among living organisms from
all sources including, inter alia, terrestrial, marine and
other aquatic ecosystems and the ecological
complexes of which they are part; this includes diver-
sity within species, between species and of ecosys-
tems’ (CBD Article 2).
As a consequence of the wide definition of biological
diversity in the CBD, one must more precisely identify
the components of biodiversity to assess the ‘effects
on biodiversity’ of different forest management strate-
gies. The next step would be to assess how these
components may be affected – ideally in quantitative
terms – and then judge if the effects are positive or
not. Decision makers, having the task of balancing
biodiversity concerns against other societal needs, like
mitigation of climate change, will be helped if ‘critical
levels/thresholds’ of biodiversity impact are provided.
Management strategies to promote long-term storage
of carbon on forest land may impact on biological diver-
sity - and will also have to take biological diversity into
account - as there are several biodiversity links to the
amount of accumulated carbon and the processes
affecting the carbon flow in ecosystems (cf. e.g.
BIODEPTH, 2007). Such management strategies could
include mitigation of ecosystem disturbances, such as
fire and other hazards creating carbon emissions,
afforestation and other measures to increase the area
of forest land, stand management practices (silvicul-
ture) that increase carbon sequestration, the life cycle
of forest products and finally substituting fossil fuels
with forest biomass (Obersteiner et al. 2005).
In the following we will, based upon ideas developed
within the IUFRO Unit 8.02.01 – ‘Key factors and
ecological functions for forest biodiversity’, identify
biodiversity components as a basis for policy and
management and try to apply this to potential manage-
ment strategies aimed at increasing the long-term
storage of carbon in the forest landscape. The
perspective will be European but we hope our
approach is more generally valid.
2. Key factors of forest
biological diversity
The tropical, temperate and boreal forests offer
diverse sets of habitats for plants, animals and micro-
organisms. They hold the vast majority of the world’s
terrestrial species (CBD). Together with the abiotic
components of the ecosystem the species create a
complex pattern of interactions, which to a larger or
smaller extent is influenced by human interventions.
Given the large number of species and ecological inter-
actions, it is difficult to generalize information derived
from measurements of biodiversity, such as a set of
species from one or a few taxonomic groups. A Euro-
-2-

pean research network has presented a model to
assess forest biological diversity based upon the
components ‘composition’, ‘structure’ and ‘function’
further specified by ‘key factors’ (Larsson 2001). Key
factors have a major influence or directly reflect the
variation in forest biodiversity. There are both practical
and theoretical advantages of the ‘key factor approach’
to assessing forest biodiversity; e.g. it has been shown
that key factors to a large extent may be assessed by
existing forestry data, e.g. in national forest invento-
ries. Furthermore this approach is well suited to
assess biodiversity in ‘the wider landscape’ and thus
should be applicable in discussing forest landscape
management for climate change mitigation. The key
factors relevant to forest management for climate miti-
gation should reflect the biodiversity components and
related functions linked to carbon accumulation and
flow, but also widely reflect the effects of different
climate management options on forest biological diver-
sity. Figure 1 shows the conceptual model that will be
used as a basis for further discussion. The figure high-
lights a number of important aspects to consider when
planning the management of forest landscapes for
climate change mitigation:
• Biodiversity in soil as well as above ground should
be considered. A significant part of the carbon
stock of a forest ecosystem is found in the litter
and soil organic matter pool (cf. Table 1); the
preservation of forest vegetation and its diversity is
-3-
Site
(soil, nutrients, climate, water)
Atmosphere
(nitrogen, pollutants)
Key
factors
Pastand present
management
Tree species and
genotypes
Stand volume and
structure
Deadwood
Ground vegetation
Disturbances:
Fellings
Fire
Nutrientstatus:
Humus/soil organic
content
Water,pH
Base saturation
Soil
bio-diversity
andfunction
Above
ground
bio-diversity
Naturalness and
succession
dynamics
Figure 1.
Some key factors significant for relating biological diversity, carbon stock and processes affecting the carbon flow
in the forest ecosystem.
Table 1.
Carbon storage in different forest ecosystems. More
than 70% of the carbon was found in the soil organic
pool for broadleaved woodland. The corresponding
figures for Boreal- and Warm-temperate forest were
38 and 21%, respectively.
Carbon pool estimates in forest ecosystems
C[tha
-1]
Carbon pool
Boreal forests,
Sweden1
Broad-leaved
woodlands,
UK2
Warm-
temperate
Beech forest,
New Zealand3
Aboveground
living biomass 35 100 193
Belowground
living biomass 10 28 47
Dead wood 0.85 2.0 25
Litter 3143.3 7.3
Soil organic
carbon 454335 71
Total 122 468 344
Note:
Definitions of carbon pools are not perfectly harmonized. E.g., soil
organic carbon refers to 0-500 mm depth for Boreal- and Broad-
leaved forests, and to 0-600 mm depth for Warm-temperate
forests
Sources:
1) Ranneby et al., 1987, 2) Patenaude et al., 2003, 3) Hart et al., 2003
and 4) Karltun, personal communication.

therefore instrumental to the conservation of
below-ground carbon reserves, though there are
functional links to a number of ecological and biodi-
versity factors. E.g. in dryland forests biodiversity
loss can contribute to reduced carbon stocks and
desertification (Figure 2).
• ‘Naturalness’ and successional dynamics are crucial
to consider when discussing management of forest
landscapes for biodiversity and carbon stocks.
• Disturbances, from e.g. forestry practices (e.g.
felling) or natural (e.g. fire) impact on biodiversity.
Although a common set of key factors is generally
valid to characterize the biodiversity of European
forests, and may serve as a basis for ecological
assessments, there are large bio-geographical and site
differences in the relative importance of key factors
(Marchetti, 2004). An example is deadwood, which is
an important feature both as carbon stock and to
secure important components of biodiversity in some
forests, but may be considered a problem in other
forests, because of increased risk of anthropogenic
fires.
Any forest biodiversity assessments must therfore be
adapted to specific forest types. Barbati et al. (2006)
identify 14 main forest categories as the highest
aggregation level in a proposed European forest type
scheme. These main categories of the European
forests need to be identified in international reporting
and assessments.
3. A landscape approach to
forest management for carbon
sequestration
As mentioned in the previous section, ‘naturalness’
may be a starting point for discussing strategic
management of forest landscapes for biodiversity.
Taking the example of Europe, most land area (mainly
except high mountain, wetlands and some dry grass-
land areas) would be forest. Today this is only the case
in northern Europe. The intense and long human
landuse is reflected in forest fragmentation and re-
duction in forest area in many European countries.
The following text considers the impact of different
forest management strategies on carbon storage in
-4-
Figure 2.
Linkages and feedback loops among biodiversity loss, climate change and desertification.
Source: Millenium Ecosystem Assessment, 2005

-5-
primary forests including modified natural forests, in
semi-natural forests, and in forest plantations. The
impact of such strategies is presented and linked to
the extent of the forests in their respective naturalness
categories.
Taking into account the vast forest resources of the
Russian Federation (including Siberia), about one quarter
of Europe’s forests can be considered primary forest
without clearly visible indications of human activities
(UNECE/FAO, 2005). Another 50% are modified natural
forests with little human influence. These forests mainly
belong to the boreal forest category (Barbati et al.,
2006). The main part of forests in Western Europe is
considered as semi-natural owing to intense manage-
ment. In the Czech Republic, Finland, Germany, Nether-
lands, Norway, Poland, Serbia Montenegro and Switzer-
land, the share of seminatural forests exceeds 90% of
the total forest area. The majority of the European forest
types are thus to be classified as semi-natural (cf.
Barbati et al., 2006).
Plantations are generally not dominating in Europe; in
West Europe the share is only about 6% of the total
forest area. However, the proportion of plantations is
quite considerable in the forests of the following coun-
tries: Belgium (41%), Denmark (63%), Hungary (28%),
Ireland (87%), Portugal (33%) and the United Kingdom
(68%). In the south eastern European countries the
proportion of plantations is overall higher – with a
significant part having protective functions.
Primary forests and modified natural forests
It may seem counter intuitive that primary forests
should be managed for biodiversity. The general
perception of a natural forest is that this is indeed a
biodiversity repository as well as a large carbon stock
which only needs protection. However, a main issue
both for biodiversity and carbon is that forest ecosys-
tems are naturally dynamic and subject to disturbances
and succession. Although these disturbances are not
always perceived positively they may, from a biodiver-
sity point of view, be crucial to preserve species
adapted to specific successional stages.
Two major categories of forest dynamics are often
identified by ecologists: large scale stand-replacing
disturbances and small-scale (within-stand) gap
dynamics (Hansson 1992). A typical example of large-
scale stand dynamics is the mosaic of relatively
homogenous forest stands of different ages that can
be found in boreal forests, created by natural forest
fires or maintained by clear-felling practices (Figure 3).
The main biodiversity management problem of primary
and modified natural boreal forests, at least in
Fennoscandia, is that forest fire is effectively
controlled and largely eliminated. This favours later
successional stages and increases carbon stocks but
the increase in accumulated litter will favour more
intense forest fires and thus may, in the long run make
fire control more difficult. This is notably the case also
in Mediterranean countries. From a biodiversity point
Figure 3. Boreal forest landscape; landscape mosaic is reflected by clear-cut areas Photo: Tor-Björn Larsson

of view, it is important to maintain a balance of both
early and late successional stages, each of which
provides habitat for a number of different species.
Although clear-felling practices re-create early succes-
sional stages, some species will not survive under the
conditions created by clear felling because they require
residual structures like burnt wood or standing dead
trees, which would typically be found following natural
disturbances. This concern would decrease if manage-
ment techniques like e.g. prescribed burning (of felled
areas) find more practical and political support – a
model should be sought to allow more close-to-nature
fire dynamics, while overall maintaining and enhancing
carbon stocks as well as biodiversity.
Small-scale dynamics created by trees falling individu-
ally or in small groups due to wind, snow or other
factors occur in all forests. In some forest types this is
the dominating pattern of dynamics (Figure 4). Regen-
eration of the forest takes place in these gaps; in prin-
ciple the stand will contain all age classes. Dying trees
and dead wood are also important features because
many species are specialised on specific decomposi-
tion stages of deadwood. Preserving the natural state
of these types of forest and/or letting stands develop
without human interference will increase carbon
stocks. Here we have a clear synergy between biodi-
versity conservation and carbon sequestration; from a
biodiversity point of view, a main concern is to
preserve large enough areas connected to each other
to secure that those species specialised on a specific
successional stage, (e.g. deadwood of a certain dimen-
sion and decomposition stages) get continuous access
to enough habitat to maintain their populations.
Semi-natural forests
Most European forests are considered to be semi-
natural, reflecting a long history of human use and
forestry. However, the human impact modified the
natural conditions only to some extent. This creates a
good starting point for maintaining and enhancing
forest biodiversity. The challenge for management to
enhance carbon stocks is to avoid measures that
significantly decrease the biodiversity values of the
forest but that instead maintain – or increase – the
state of biodiversity.
For example in the boreal forests clear-felling and
evenaged stand management are the preferred
forestry practises. Late successional stages and dead-
wood, two important forest features generally decline
as a result of these practices, yet both are of impor-
tance to carbon stocks as well as biodiversity.
In Europe only ca. 2/3 of the annual increment in
forests are presently harvested (UNECE/FAO, 2005).
As a consequence wood volumes and carbon stocks
are increasing.
One factor contributing to the increase in wood
volume is that forest growth rates have increased in
many forest types in Europe. This is partly because of
increased input of nitrogen from fertilizer applications
and long-range air pollution (ICP Forests, 2005). From a
biodiversity point of view this ‘eutrophication’ of the
forest ecosystem is not desirable as it leads e.g. to
increases in nitrophilous plant species, while overall
ground vegetation species diversity decreases (ICP
Forests, 2006, Ferretti et al., 2005). Application of
nitrogen fertilizer to increase carbon sequestration
may negatively affect biodiversity.
The increase in wood volumes also leads to bigger
trees, a feature associated with late successional
stages that benefits species dependent on such trees.
Some of these species seem to have a low dispersal
ability and depending on distance to source areas –
rare in the productive forest landscape - biodiversity
may not (immediately) improve as much as one might
expect. In any case, a carbon sequestration policy
favouring bigger (and older) trees is expected to
benefit biodiversity.
The increasing standing wood volumes in semi-natural
European forests also means that these forests
become darker. Where site productivity increases,
where single species forests are being converted into
mixed stands, and where early successional species
-6-
Figure 4.
Gap dynamics of Central European lowland beech forest
Photo: Tor-Björn Larsson

such as pines are replaced by other species, canopy
density increases and permits less light to the under-
storey, which in most temperate forests harbours the
majority of plant diversity. Thus plant species diversity
is commonly low following canopy closure, when leaf
area is at its maximum, until the gradual break up of
the canopy when forests become mature to overma-
ture (e.g. Halpern and Spiess 1995). Schmidt and
Weckesser (2004) found that understorey plant
species richness was greater in old, secondary spruce
stands than in mixed spruce-beech forests, owing to
the greater light availability beneath spruce. In the case
of understorey vegetation, we may have an example
of antagonistic effects between C sequestration and
biodiversity. Management practices that are likely to
increase floristic diversity in forests, will have to create
heterogenous within-stand light environments, likely to
result in reduced stocking of trees.
Management aimed at increasing dead wood provides
another opportunity to combine carbon sequestration
and biodiversity objectives because several species are
dependent on dead wood. It is considered a structural
key factor (Larsson, 2001) and a crucial indicator in the
assessment of biodiversity and naturalness of forest
systems (McComb and Lindenmayer, 1999, Skogssty-
relsen, 2001). A number of vertebrates, including
cavity-nesting birds, as well as many species of lichens,
bryophytes, fungi and invertebrates - have decreased
and/or are threatened in the semi-natural forests of
Europe (Marchetti 2004, Jonsson and Kruys 2001).
Deadwood plays an important role in long-term carbon
storage. The amount of dead wood per hectare is
slightly increasing in most of Europe (Figure 5), to
some extent a result of increased management for
biodiversity. However, the average amount is far below
that in the primary forests of the Russian Federation.
Policies to further increase the amount of dead wood
will benefit both carbon stocks and biodiversity. It
should be noted that increasing dead wood content in
most forest types is a long-term process (Figure 5). In
some forest types dead wood accumulation is not
desirable; this is particularly the case in Mediterranean
conifer forests in which woody debris must be
removed to reduce the fire risk.
In this brief overview we will only consider one more
aspect of forestry in the semi-natural forest category:
genetic improvement of forest trees. In Europe consid-
erable long-term efforts have been made to increase
forest production by moving seeds and seedlings and
narrowing the genetic variation to high production
genotypes. Moving seed material to the north (in the
northern hemisphere) may not as such be a problem in
a climate change context. If the genetic variation is
maintained – which is seldom the case – the same
should apply from a biodiversity point of view. To
narrow the genetic basis of a tree population in favour
of high production genotypes when collecting seeds in
nature or through breeding programmes is by defini-
tion in conflict with preserving biodiversity. Generally
the genetic variation in a population is important to
enable evolution to adapt to new conditions – such as
climate change. The use of ‘improved’ forest regenera-
tion material to increase volume production may be
tempting in a strategy to increase carbon sequestra-
tion but this is not a safe management strategy for the
European semi-natural forests because it may lower
the ability to adapt to future climate change.
-7-
Dead wood in forests 1990-2005
tonnes / hectare
0
5
10
15
20
25
30
35
NWE SEE Caucasus Eastern Europe
1990
2000
2005
Figure 5. Development of dead wood in forests pan-Europe.
Note: Country groupings:
NWE: Austria , Belgium, Cyprus, Czech Republic, Denmark , Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, United Kingdom, Iceland, Liechtenstein,
Norway & Switzerland.
SEE: Albania, Bulgaria, Bosnia-Herzegovina, Croatia, The Former Yugoslav Republic of Macedonia, Romania, Serbia and Montenegro & Turkey.
Caucasus: Armenia, Azerbadjan & Georgia.
Eastern Europe: Belarus, Republic of Moldova, Russian Federation & Ukraine.
Source: UNECE/FAO, 2005

Forest plantations
Planting is a preferred forest regeneration technique in
several forest types in Europe, largely considered to
belong to the semi-natural category. The internationally
agreed definition of forest plantation (FAO, 2005) has
created a lot of discussion because it focuses on struc-
turally very uniform planted forest often comprised of
exotic tree species. In the context of carbon manage-
ment the focus is on afforestation, i.e. plantations on
land that is transferred from non-forest to forest use.
The forest area is currently increasing in Europe (ca 5%
per decade, UNECE/FAO, 2005) which reflects aban-
donment of agricultural areas. About half of this, in
particular on extensively grazed land in the Mediter-
ranean, is re-growing spontaneously. This creates a
forest with high species and structural diversity, domi-
nated by native species, which is attractive from a biodi-
versity point of view. Creating a forest by spontaneous
re-growth does not require the long-term investment in
establishing new forest by planting or sowing, but the
increment in wood volume can be expected to be lower.
Planting trees, afforestation, in Europe on the other
hand has almost exclusively relied on exotics, like
Eucalyptus or North American coniferous species, or
on native trees outside their natural range. Use of
exotics, apart from creating stands with different biodi-
versity compared to native trees, is also connected
with the risk that the introduced species spread and
become invasive. In several European countries
(Ireland, France, Spain) afforestation by exotic or
species not native to the site has successfully created
a basis for wood-based industries, but the ecological
and biodiversity states of these plantations are under
debate, in Europe and elsewhere (cf. IUFRO, 2005).
Beneficial effects of plantations on biodiversity can be
achieved in three ways: At the stand level a modified
ecosystem is created, however it has been shown e.g.
in the large Irish BIOFOREST study that surprisingly
much of native biodiversity can be retained by a set of
feasible considerations in the management (Iremonger
et al., 2006). The effects of plantations on biodiversity
on the landscape level have been shown in some case
studies. Where plantations originate from afforesta-
tion, replacing non-forest land use, there should be
synergistic effects of increasing C sequestration and
biodiversity in the landscape.
Afforestation with the explicit main purpose to
increase carbon stocks is likely to rely on highly
productive tree material, including biotechnologically
‘improved’ genotypes. The most extreme will be
genetically modified organism (GMO) trees that even
may include genes to increase resistence to defolia-
tors or diseases. From a biodiversity viewpoint, this
would be a very risky strategy, because such genes
might spread into native populations.
4. Future prospects and
policy options
The previous section has demonstrated a few main
principles for a strategy to increase carbon stocks in
forests which is not in conflict with the aim to preserve
and enhance forest biodiversity:
1. Primary forests and modified natural forests
• Controlling large-scale natural disturbances like
forest fire in natural forests is one option to
increase carbon stocks but is advisable only in a
medium-term perspective. A long-term strategy
to preserve biodiversity in natural systems
should, to a certain degree, re-introduce the
successional dynamics of habitats.
• Forest areas characterised by small-scale gap
dynamics will, without interference, over time
develop positively both from a carbon stock and
biodiversity perspective.
2. Semi-natural forests
• Extending the rotation period between felling
will increase carbon stocks and promote biodi-
versity dependent on large trees and late
successional stages.
-8-
0
10
20
30
40
50
60
natural forest planted forest
0
3
6
9
12
15
18
natural forest planted forest
all species endemic species
Carmil
Rille
Carmil
Rille
Figure 6. The effects of forest plantations on biodiversity: decrease in soil fauna (number of species)
Note:. Springtails (Order: Collembola) play a major role in breakdown of litter, soil constitution and structure. A study on Collembolan species
richness in two areas (Carmil, Rille) in Ariège Pyrenees, France, showed significantly lower richness in conifer plantations than under native
beech forests. The difference is even more obvious for the endemic species.
Source: EEA, 2002.

• Promoting dead wood (by not removing
damaged or fallen trees) enhances both carbon
stocks and biodiversity.
• Applying fertilizers to increase forest production
will negatively impact a number of forest
species.
• Increasing forest production by tree breeding
resulting in a more limited gene pool is a debat-
able strategy from a biodiversity and climate
change adaption point of view.
3. Forest plantations
• Unassisted regeneration of site-native forest on
e.g. abandoned agricultural and grazing land is,
from a biodiversity point of view, clearly
preferred over afforestation with exotic or non
site-native tree species. It may, however, be
considered a low-efficiency, but cheap, strategy
to increase carbon stocks.
• Regeneration by planting biotechnologically
improved fast-growing trees, including GMO
trees, is a high-risk and controversial strategy to
increase carbon stocks and/or to create a basis
for bioenergy from forest.
These main principles are of major importance in the
above main forest naturalness categories but may be
more generally applicable depending on the actual
situation.
The global forum developing the general biodiversity
policy is the UN Convention on Biological Diversity
(CBD). At the Conference of the Parties in 2006 (CBD
COP-8) issues related to forest biodiversity and poten-
tial measures to increase carbon stocks (often as well
promoting increased bioenergy potential of forests)
were discussed under several themes. The focus was
on the issues dealt with under ‘Forest plantations’
above. The discussion under the forest theme – which
will become a major one in the upcoming CBD COP-9
in 2008 – showed an emerging concern about GMO
trees (cf. CBD, 2006b). When discussing invasive
alien species several countries proposed an explicit
statement that afforestation as a measure to mitigate
climate change should avoid planting such non-native
tree species which could become invasive. It was,
however, considered inappropriate to issue a political
recommendation in an area regulated by the UN
Framework Convention on Climate Change so the
CBD just stressed the need to ensure information
exchange between the two conventions (CBD, 2006
a). As shown in this brief review balancing biodiversity
and climate concerns may result in both win-win
strategies and some potential conflicts in need of polit-
ical compromises. IUFRO can contribute scientific
support to this dialogue.
5. Glossary
afforestation: planting of forest on land which for a long time (> 50 years) has not
been forested
biodiversity: the variability among living organisms from all sources including, inter
alia, terrestrial, marine and other aquatic ecosystems and the ecological
complexes of which they are part; this includes diversity within species,
between species and of ecosystems
biomass: the total dry organic matter contained within living organisms or ecosys-
tems per unit area
Convention on Biological Diversity: http://www.biodiv.org/default.shtml
eutrophication: the process by which an ecosystem becomes enriched in available
nutrients, especially N and P
stand: a contiguous group of trees sufficiently homogenous in age- and size-class
distribution, species composition and structure and growing on a site of
sufficiently uniform quality to be a distinguishable unit, to which the same
management practices can be applied.
forest: a collection of stands.
forest plantation: Intensively managed forest stands resulting from afforestation
or reforestation through artificial regeneration (planting or sowing). Plan-
tations are commonly even-aged, consist of only one or few tree species
(often exotics) that are managed to make full use of the productive
capacity of the site. They have a regular shape with fixed and clearly
defined boundaries. They may require high inputs of fossil energy and
labour.
key factor of biodiversity: factors having a major influence or directly reflecting
the variation in forest biodiversity.
naturalness: Area of forest and other wooded land, classified by „undisturbed by
man“, by „semi-natural“ or by „plantations“, each by forest type.
nitrophilous species: species that require high levels of nitrogen availability for
optimal growth; favoured by (increased) nitrogen availability in the
ecosystem.
sequestration: removal and storage; carbon dioxide taken from the atmosphere
into plants by photosynthesis.
sink: a process or mechanism which removes carbon from the atmosphere.
soil biodiversity: organisms in the soil; functionally commonly divided into meso-
fauna (several taxa e.g. mites, nematodes, collembolan etc.) and microor-
ganisms (fungi, bacteria).
source: opposite of a sink.
succession: development of an ecosystem and its biodiversity composition over
time, e.g. in response to a disturbance factor. A typical succession occurs
in natural forest after forest fire, starting with pioneer organisms estab-
lishing themselves on newly burnt areas, followed by the community of
closed forest stand and ending with the species specialized to/dominating
in the old-growth forest.
6. Further reading
Barbati, A., Corona, P. and Marchetti, M., 2006. European forest
types. Categories and types for sustainable forest manage-
ment reporting and policy. European Environment Agency
Technical Report 9/2006.
BIODEPTH (Biodiversity and Ecological Processes in Terrestrial
Herbaceous Ecosystems), 2007. Results and Relevance
pages of the now completed BIODEPTH project.
http://www.cpb.bio.ic.ac.uk/biodepth/results_and_relevance.h
tml (Accessed February 2007)
CBD (UN Convention on Biological Diversity), 2006a. Alien species
that threaten ecosystems, habitats or species (Article 8 (h):
further consideration of gaps and inconsistencies in the inter-
national regulatory framework. CBD Eight Conference of the
Parties Decision VIII/27.
CBD (UN Convention on Biological Diversity), 2006b. Forest biolog-
ical diversity: implementation of the programme of work. CBD
Eight Conference of the Parties Decision VIII/19.
EEA (European Environment Agency), 2002. Environmental signals
-9-

2002. EEA Environmental Assessment Report 9. Figure 16 is
based on data in Deharveng, 1996.
FAO (Food and Agriculture Organization of the United Nations),
2005. FRA 2005 Terms and definitions. http://www.fao.org/
forestry/site/fra2005terms/en/
Ferretti, M., Caldersi, M., Bussotti, F., Campetella, G., Canullo, R.,
Costantini, A., Fabbio, G., and Mosello, R., 2005. Factors influ-
encing vascular species richness in the CONCOFOR perma-
nent monitoring plots. Annali .CR.A.ISSEL 30:97106.
Halpern, C.B., and Spiess, T.A., 1995. Plant species diversity in
natural and managed forests of the Pacific Northwest. Ecolog-
ical Applications 5:913-934
Hansson, L. (Ed.), 1992. Ecological Principles of Nature Conserva-
tion. Elsevier, 436 pp.
Hart, P.B.S., Clinton, P.W., Allen, R.B., Nordmeyer A.H. and Evans,
G., 2003. Biomass and macronutrients (above- and below-
ground) in a New Zealand beech (Nothofagus) forest
ecosystem: implications for carbon storage and sustainable
forest management. Forest Ecology and Management
174:281-294.
ICP Forests (UN Convention on Longrange Transboundary Air Pollu-
tion International Cooperative Programme on Assessment
and Monitoring of Air Pollution Effects on Forests), 2005.
Europe´s Forests in changing Environment. Twenty years of
Monitoring Forest Condition by ICP Forests. UNECE, Geneva.
ICP Forests (UN Convention on Longrange Transboundary Air Pollu-
tion International Cooperative Programme on Assessment
and Monitoring of Air Pollution Effects on Forests), 2006. The
Condition of Forests in Europe. 2006 Executive Report.
Federal Research Centre for Forestry and Forest Products
(BFH), Hamburg
Iremonger, S., O’Halloran, J., Kelly, D.L, Wilson, M.W., Smith, G.F.,
Gittings, T., Giller, P.S., Mitchell, F.J.G., Oxbrough, A., Coote,
L., French, L., O’Donoghue, S., McKee, A.M., Pithon, J.,
O’Sullivan, A., Neville, P., O’Donnell, V., Cummins, V., Kelly,
T.C. Dowding P., 2006. Biodiversity in Irish Plantation Forests.
EPA and COFORD, Dublin. 82 pp. http://bioforest.ucc.ie/
(Accessed March 2007)
IUFRO, 2005. Presentations an conclusions of the IUFRO Division 8
Conference: Biodiversity and Conservation Biology of ecosys-
tems in Plantation Forests, Bordeaux, France, 2629 April,
2005. http://www.pierroton.inra.fr/IEFC/affiche_page.php?
page=manif_2005_bpf&langue=en (Accessed February 2007).
Jonsson, B.G. and Kruys, N., 2001. Ecology of woody debris in
forests. Ecol. Bull. 49.
Karltun, E. Personal communication. The Swedish Forest Soil Inven-
tory. Erik.Karltun@sml.slu.se
Larsson, TB, (Coordinator) 2001. Biodiversity Evaluation Tools for
European Forests. Ecol. Bull. 50. Elaborated in collaboration
with some 45 experts representing 27 organisations from 18
countries
Marchetti, M. (Ed.), 2004. Monitoring and Indicators of Forest biodi-
versity in Europe – From Ideas to Operationality. European
Forest Institute EFI Proceedings 51, 2004
McComb, W., and Lindenmayer, J., 1999. Dying, dead, and down
trees. In Maintaining Biodiversity in Forest Ecosystems.
Edited by M.L. Hunter. Cambridge University Press,
Cambridge, UK. pp. 335–372.
Millennium Ecosystem Assessment, 2005 Ecosystems and Human
Wellbeing: Desertification Synthesis. World Resources Insti-
tute, Washington, D.C.
Obersteiner, M., Benitez, P., McCallum, I., Lexer, M., Nilsson, S.,
Schlamadinger, B., Sohngen, B., and Yamagata, Y., 2005. The
Economics of Carbon Sequestration in Forests. IUFRO enote
Issue 3. The Role of Forests in Carbon Cycles, Sequestration,
and Storage. http://www.iufro.org/science/taskforces/
(Accessed February 2007)
Patenaude, G.L., Briggs, B.D.J., Milne, R., Rowland, C.S., Dawson,
T.P. and Pryor, S.N., 2003. The carbon pool in a British semi-
natural woodland. Forestry 76:109-119.
Ranneby, B., Cruse T., Hägglund B., Jonasson H., and Swärd, J.,
1987. Designing new national forest survey for Sweden.
Studia Forestalia Suecica 177. 29 p.
Schmidt, W. and Weckesser, M., 2004. Raumzeitliche Dynamik der
Vegetation nach Waldumbau - Struktur und Diversität der
Bodenvegetation in Mischwäldern und an Wald- und Wegrän-
dern. Berichte Forschungszentrum Waldökosysteme
B71:111-132
Skogsstyrelsen, F., 2001. Skogsbränsle, hot eller möjlighet—vägled-
ning till miljövänligt skogsbränsleuttag. Skogsstyrelsen förlag,
Kristianstad, Sweden (in Swedish).
UNECE/FAO, 2005. Global Forest Resources Assessment 2005.
Progress towards sustainable forest management. FAO
Forestry Paper 147. UNECE/FAO, Rome
-10-
All Newsletters are available free of charge at
http://www.iufro.org/science/task-forces/carbon/
Further publications in this series
Issue 1: Forests and the Global Carbon Cycle: Sources and Sinks
Issue 2: Influences of Natural and Human-Induced Disturbances on Forest Carbon Sequestration and Storage
Issue 3: The Economics of Carbon Sequestration in Forests
Issue 4: Forest Management and Carbon Sequestration
Issue 5: Climate Change Mitigation, Forest Management and Effects on Biological Diversity.