G. Kohlmaier • M. Weber • R. Houghton

Carbon Dioxide Mitigation in Forestry and Wood Industry

Springer-Verlag Berlin Heidelberg GmbH

Gundolf H. Kohlmaier· Michael Weber· Richard A. Houghton

Carbon Dioxide Mitigation in Forestry

and Wood Industry

With 68 Figures and 63 Tables

Springer

Editors

PROF. DR. GUNDOLF H. KOHLMAlER

University of Frankfurt

Institute of Physical and Theoretical Chemistry

Marie-Curie-Str. 11

60439 Frankfurt

Germany

DR. MICHAEL WEBER

University of Munich Chair of Silviculture and Forest Management Hohenbachernstr. 22

85354 Freising Germany

DR. DR. RICHARD A. HOUGHTON

WoodsHole Research Center 13 Church Street Woodshole, Mass. 02543 USA

Sponsored by the Andreas Stihl Foundation

ISBN 978-3-642-08330-3 ISBN 978-3-662-03608-2 (eBook) DOI 10.1007/978-3-662-03608-2

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Die Deutsche Bibliothek - CIP-Einheitsaufnahme

Carbon Dioxide Mitigation in Forestry and Wood Industry: with 63 tables / GundolfH. Kohlmaier; Michael Weber; Richard A. Houghton. - Berlin; Heidelberg; New York; Barcelona; Budapest; Hong Kong; London; Milan; Paris; Santa Clara; Singapore; Tokyo: Springer 1998

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© Springer-Verlag Berlin Heidelberg 1998 Originally published by Springer-Verlag Berlin Heidelberg New York in 1998. Softcover reprint of the hardcover 1 st edition 1998

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Acknowledgements

The organizers of the workshop Gundolf Kohlmaier of the Johann Wolfgang Goethe University, Frankfurt and Michael Weber of the Ludwig-Maximilians­University, Munich should like to thank the Andreas Stihl Foundation in Stuttgart­Waiblingen for the financial support of this workshop. We should like to extend our thanks to Canadian Pulp and Paper lndustry Information Centre Europe in Brussels who supported the travel of one Canadian scientist.

Editors' Summary Statement

Introduction

The lntergovernmental Panel on Climate Change (IPCC) has recently summarized the state ofthe art in research on climate change (Climate Change 1995). The most up to date research findings have been divided into three volumes:

• the Science ofClimate Change (working group I), • the Impacts, Adaption and Mitigation of Climate Change (working group II),

and • the Economic and Social Dimensions ofClimate Change (working group III)

There is a general consensus that a serious change in climate can only be avoided if the future emissions of greenhouse gases are reduced considerably from the business as usual projection and if at the same time the natural sinks for greenhouse gases, in particular that of CO2, are maintained at the present level or preferrably increased. Forests, forestry and forestry industry are important parts of the global carbon cycle and therefore they are also part of the mitigation potentials in at least a threefold way:

1. During the time period between 1980 and 1989 there was a net emission of CO2 from changes in tropical land use (mostly tropical deforestation) of 1.6 +/- 1 GtC/a, but at the same time it was estimated that the forests in the northem hemisphere have taken up 0.5 +/- 0.5 GtC/a and additionally other terrestrial sinks (including tropical forests where no clearing took place) have been a carbon sink ofthe order of l.3 +/- l.5 GtC/a (working group I: Chapter 2: Radiative Forcing of Climate Change, Table 2.1).

2. The expected climate change may have a serious impact on the structure and functioning of forests. The impact starts at a specific plant physiological level, such as photosynthesis, respiration and allocation, and leads to a changed net primary production, net annual increment, and net ecosystem production, which influences the level of competition between different species and which finally can result in a changed geographical distribution of forests with or with­out an intermediate stage of disruption (working group II: Part 11 - Assessment of Impacts and Adaption Options, Chapter 1: Climate Change Impact on Forests). There will be feedbacks on the climate system which depend on a CO2 uptake through a combined CO2 and nitrogen fertilization effect or a CO2

and methane release from decomposition processes in the litter and the soil (working group I: Chapter 9: Terrestrial Biotic Responses to Environmental Change and Feedbacks to Climate).

VIII Editors' Summary Statement

3. The management of forests provides various opportunities for the mitigation of greenhouse gas emissions (working group II: Part 1II, Assessment of Mitigation Options, Chapter 24: Management ofForests for Mitigation ofGreenhouse Gas Emissions). These include (i) the conservation of carbon pools in existing forests, (ii) forest management options to increase the forest area or the carbon density of forest and (iii) substitution of fossil fuels and energy intensive materials.

This workshop focussed on the opportunities of carbon mitigation potentials in the industrialized countries in cooperation with and in support of the developing countries. The region of temperate and boreal forests is the main domain of the industrialized countries. Here workshop participants came from the United States and Canada, from different parts of Europe and from the Former Soviet Union. The workshop's first task was to identifY the present situation both with respect to the forest land area, the standing biomass, the net annual increment, the net annual fellings, and the disturbance regimes caused by large frres, droughts, storms, and insect infestations. From the difference between net annual growth and net annual fellings and disturbances, a carbon balance can be established. The future development under different scenarios will then certainly depend on the state of the forests: their species distribution and age class characteristics are important, together with the future climate and disturbances as weIl as the decision of forest management including reforestation and afforestation and annual felling plans.

lt was very exiting and interesting to observe that the forestry of Russia, Canada, and Europe showed their own characteristics in particular with respect to the forestry management, the wood industry and the general economic conditions. Despite this fact there was the unanimous opinion that on a worldwide basis forest management could result in important CO2 mitigation opportunities perhaps up to 12-15 % of the projected cumulative fossil fuel carbon emission over the period from 1996 to 2050, in agreement with the IPCC report.

In order to have good and intensive discussions, a selected group of scientists coming from both the field offorestry and the modelling of biogeochemical cycles, integrated system analysis, and life cycle assessment were invited along with still too few people from the wood industry and politics to discuss the options for CO2

mitigation resulting from the assessm~nt of the state of forests. We were very fortunate to have the leading scientists on "forests and the global carbon cycle" among the participants from Canada, the United States, France, Italy, The United Kingdom, The Netherlands, Germany, Austria, Switzerland, Finland, and the Former Soviet Union.

Carbon Dioxide Mitigation in Forestry and Wood Industry IX

Background

Forests represent a huge storage of carbon since they hold about 80 % of the carbon fixed in the living biota of the global biosphere. Changes in area or growing stock of forests results in fluxes of carbon from forests (both living biota and soil carbon) to the atmosphere or vice versa. As a result of deforestation and degradation forests in the tropical zone currently are a source of 1.6 (+/- 1.0) Gt C/a, whereas forests in the temperate and boreal zone are thought to act as sinks for atmospheric carbon of 0.5 (+/- 0.5) Gt C/a due to recovery from past disturbances, active forest management, fertilization effects and afforestations. Altogether the total living biota and soils of the earth are estimated to be a carbon sink of the order of 1.8 Gt C/a (during the time period between 1980 and 1989) wh ich, however, is nearly compensated by the above mentioned deforestation in the tropical zone.

Conservation and adapted management of existing forests, and establishment of new forests as weil as the substitution of fossil fuel based energy and products by biomass could increase the fixation of carbon and sequester COz from the at­mosphere. During the last years knowledge of the mitigation potentials of forestry measures has increased drastically. In most of the industrialized countries the importance of forests in the national carbon balances and the possibilities for increasing it have been recognized. In its 1995 report the IPCC provided a com­prehensive assessment of the forestry mitigation options and potentials on aglobai scale. They estimated that 12 to 15 % of the projected cumulative fossil fuel C emission over the period 1995 to 2050 could be conserved and sequestered by forestry measures during the same period. This amount will further increase if the C-saving-effects of substituting fossil fuels and energy-expensive materials by wood are considered. Forestry options offer a large mitigation potential with modest costs, low risk, and other benefits. They are seen as one of the few no regrets opportunities available in most countries all over the world.

Despite these beneficial characteristics programs for the implementation of forestry measures are still rare and in their infancy. Until now there exist only few mitigation projects which are run mainly by private or industrial initiatives, such as the FACE foundation in the Netherlands, PRIMA KLIMA in Germany or Global ReLeaf in the USo Because remarkable effects of forestry mitigation options can be achieved only if they are implemeted on larger areas, there is an urgent need for the development of such measures. One intention of the workshop was to assess the possibilities and the scientific background for such programs.

Because early mitigation action may increase flexibility in moving towards stabilization of atmospheric COz concentration (IPCC 1995), it is astonishing that the forestry option as one of the few no regrets options is not yet more in the focus of policymakers. Is this a result of lacking scientific knowledge, of missing advice by scientists or the absence of scientifically based implementation programs? One of the objectives of this workshop was to find answers to these kinds of questions.

X Editors' Summary Statement

Organization and Objectives of the Workshop

The goal of the workshop was directed towards theoretical and practical guidelines to use and enhance the potential of growing forests to absorb CO2 emitted from fossil fuel combustion. It was embedded in our knowledge that the land eco­systems are at present a sink for atmospheric CO2 except for those regions where devastating deforestation is taking place. Planting a tree can contribute towards an improved carbon balance with respect to the feared atmospheric CO2 increase. Furthermore trees and particulary forests provide additional benefits and functions which have been summarized by the UN-ECEIFAO 1990 Forest Ressource Assessment (Vol. 11) by the following key services:

• wood production • soil protection • watersheds • grazing land • hunting grounds • nature conservation • recreation

With respect to the CO2 balance (which of course is only the most important greenhouse gas among others like methane, dinitrogen oxide, and CFCs) forests are the most important vegetation type to store carbon on land.

Within the theme of the workshop: "Carbon mitigation potential of forestry and wood industry" we wanted to analyze at least six different levels of the problem. These were: 1. To analyze the present contribution of the temperature and boreal zone forests

to the CO2 sources and sinks, those zones representing mostly the in­dustrialized countries, while the developing countries are mostly in the tropical zone. It is therefore interesting to ask how large the CO2 absorption or emission of forests is compared to the fossil fuel CO2 emissions in different nations of the world.

2. To ask if the mitigation potential of forests, mainly in the industrialized countries could be maintained or increased in the future through reforestation or afforestation or better management. At the same time the question needs to be asked ofthe developing countries iftheir future socioeconomic development allows for a reduction of CO2 emissions through the support of the industrialized nations.

3. To examine the question, whether the standing stock in biomass and accompanying soil carbon could be increased over the period of the next 30-100 years or whether it would be more favourable to stimulate the use of wood in substitution for structural materials, thus increasing here the standing stock of wood products and at the same time saving fossil fuels or whether the

Carbon Dioxide Mitigation in Forestry and Wood lndustry Xl

use of fuelwood could or should be increased substituting directiy fossil fuel energy. It should be mentioned that in the developing countries bioenergy from forests and energy from residues are the most important primary energy constituents.

4. To emphasize the close connection between forestry and the wood industry, as a cooperation of both is needed to find an optimum solution. This connection already exists in some parts of the world, e.g. in the United States, where the timber company is forest owner, forest manager and timber producer (in which, however, the present goal of optimum profit needs to shift in the direction of sustainability of both forests and climate); in Canada, where the forestry companies mostiy lease land from the state and provide both the forestry management and the wood industry in one company or like in some countries in Europe, e.g. Germany, where the forests may be private or state or com­munity owned and where different forestry regimes are practized depending on ownerhip and where the wood industry again is aseparate company.

5. To see the task of the industrialized countries in the realization of carbon mitigation and in providing good examples for the developing countries and to see where cooperation is possible within the programs of joint implementation.

6. To analyze the future capacity of the forests both with respect to the expected changing climate and the future socioeconomic development.

The workshop was organized into the following main sections dealing the following topics:

• A perspective from the Northern Countries - Forest Dynamics and Carbon Budgets,

• Focus on the tropical and subtropical forests - Deforestation and reforestation­emerging programs of sustainable development,

• Reforestation and protection of forests as a carbon sink and forestry activities which lead to an economic use ofwood and other services ofthe forest,

• Timber in a future world - substitute for high energy materials and fossil fuels,

• Forest response to climate change and socioeconomic pressures, and

• a view from the politics.

Participants from different countries of the world presented a first hand assessment of their own countries. Their expertise in different fields of forestry, wood industry, climate and modelling provided not only their newest research results but contributed also to interesting workshop dicussions.

It became entirely clear that only concerted actions of the different countries of the world could lead to successful mitigation measures through forestry and wood industry. Guided by the question of what the industrialized countries could do to mitigate the CO2 emission or increase the corresponding sinks for CO2, the forests

XII Editors' Summary Statement

of Europe, the forests of North America and the forests of the Former Soviet Union were one key focus. Anatoly Shvidenko and Sten Nilsson told how the dynamics of the Russian forest resources contribute to the carbon budget.

David Price and Mike Apps emphasised the importance of disturbances in the Canadian forest ecosystem carbon budget. Timo Karjalainen demonstrated that a large proportion of the national greenhouse gas emissions are sequested by the forest sector in Finnland, and how carbon sequestation may change in warmer climate. Norbert Weber, Klaus Böswald and Michael Weber considered the forest resources of Europe with particular reference to Germany, while Richard A. Houghton from the United States summarized the historical role of forests in the global carbon cycle, reflecting both on the forest resources of the temperate and boreal zone as weil as on those of the tropical forests. The tropical forest assessment by remote sensing through Phillipe Mayaux and Jean Paul Malingreau showed the present extent of forests and the rates of deforestation.

Tropical forest action plans were discussed by Susanne Weyers from Germany and by Hans Verweij ofthe FACE foundation in The Netherlands. JosefReichholf from Germany examined the question of the conservation of biodiversity, par­ticularily in the tropical countries, and measures of achievement which at the same time could lead to climate stabilization.

Any carbon mitigation through forestry starts out with an assessment of the world areas suitable for reforestation programs. Wolfgang Schopfhauser from Austria emphasized that although these areas may be quite large worldwide, the areas really available for reforestation are much smaller because of competing land use by other purposes like agriculture, e.g. lncreased carbon mitigation can also be achieved through aseries of forestry management actions combined with the optimal turnover time of felling. Norbert Weber compared selected afforestation aims at European, national and regional levels with afforestation experiences in the respective areas. Klaus Böswald explained the current role of German forests and forestry in the national carbon budget and options to increase it. Michael Weber and Klaus Böswald referenced the 1993 assessment of Burschel et al. which was one ofthe first main efforts to consider the carbon mitigation potential offorestry.

In the section "Timber in a future world" Klaus Richter discussed the eco­balance of wood products while Hubert Fritz offered examples of how to use more wood in building. Wood as bioenergy needs to reflect not only the carbon substitution potential but also the efficiency and the emission aspects of biomass burning. Bernhard Schlamadinger of Austria analyzed with the use of computer models the carbon implications of bioenergy and the necessary land use change, strategies while Arno Strehler of Germany focused on the efficiency and emission aspects of biomass burning.

The change in climate through additional greenhouse gases in the atmosphere is a major component of global change. Possible future scenarios of global change can be best analyzed with dynamic process models wh ich take an integrated assessment point of view. The workshop participants reporting in the section "Forest response to climate change and socioeconomic pressures" emphasized the

Carbon Dioxide Mitigation in Forestry and Wood Industry XIll

uncertainty of future predictions. Nevertheless the forests including both their biota and soils play a major role in the carbon cycle, connecting the reservoirs of the atmosphere, land biota and oceans. Without deforestation the land biota and the oceans would be sinks for carbon of similar order (2.0 Gtla for the ocean and 1.6 GtC/a for the land biota). Gundolf Kohlmaier reported on the role of the biota and particularily the forests within the future IPCC stabilization and GCM climate scenarios, while Christof Häger examined the expected annual increments within different countries within the temperate and boreal zone. Melvin Cannell from Great Britain presented model estimations obtained at his institute of the impact of climate change on forest ecosystems. Bernard Saugier of France emphasized the direct effect of increased CO2 levels in the atmosphere, which in part can be observed today in the increased growth levels of forest ecosystems relative to the turn of the century (tree ring analysis). Joseph Alcamo showed that integrated scenarios of global change must include both climate and socioeconomic factors.

In the section "A View from the Politics" Sigrid Strich of the German Ministry of Food, Agriculture and Forestry emphasized the competitionalland use between agriculture, forestry, recreation and nature conservation. She feIt that the great potential of carbon mitigation could be obtained through an enhanced use of tim­ber. Franzjosef Schafhausen from the German Federal Ministry for Environment, Nature Protection and Nuclear Safety gave an analysis ofthe potential for different mitigation options within and outside of forestry and wood industry. He discussed joint implementation for reforestation programs with not only countries in the tropics but economically weak countries within the OECD.

Key Findings

Role of forests within the Carbon Cycle The workshop participants agreed that the biota constitute a most important part of the global carbon cycle where CO2 is exchanged between the reservoirs atmo­sphere (A), land biosphere (B) including soils, and the oceans (0). The exchange fluxes between A and Band A and ° are of the same order of magnitude of 90 -140 GtC/a, large compared to net flux offossil fuel CO2 emission of the order of 6 tC/a (working group I, IPCC 1995). The sizes of the reservoirs A and Bare again comparable with 750 and 550 GtC resp., that ofthe ocean is ofthe order of 38000 GtC, about 50 times larger than that of the atmosphere. Net fluxes arise in response to direct or indirect anthropogenic forcing e.g. to fossil fuel CO2 flux into the atmosphere through deforestation not counterbalanced by regrowth or refore­station ('" 1.6 GtC/a) in the tropical region mostly, and through short term climate variation or long term climatic trends. One key finding of the IPCC study 1995 was that in the decade from 1980 to 1989 average fossil fuel emissions of 5.5 GtC/a led to an ocean uptake of 2.0 +/- 0.5 GtC with areminder of 3.5 GtC/a

XIV Editors' Summary Statement

remaining airborne in the atmosphere. This estimate is based on the assumption that the land biosphere remains approximately CO2 neutral in as much as the COz emission from forest clearing is counterbalanced by sink activity of the biota of approximately the same flux in the reverse direction. The so called missing sink is most probably due to a combination of effects, namely the COz fertilization effect arising from increasing levels in atmospheric COz, the nitrogen fertilization effect arising from deposition of anthropogenically released nitrogen compounds, the age class distribution of forests and their resulting annual increment of growth, which is presently not counterbalanced by the total annual cuts and finally by the variation in climate including changes in radiation induced by volcanic activity. On the interannual time scale the effect of varying temperature is clearly noticed in the atmospheric COz-budget which can be related to a change in both net primary production and heterotrophic respiration of the land biosphere (Keeling and Whorf, Nature, 382,146-149,1996).

The forests of the tropical, temperate and boreal zone constitute an important part of the global vegetation. They cover II % (tropical forests) (these and the following percentages have been evaluated from Bolin et al.: The Greenhouse Effect, Climate Change and Ecosystems, SCOPE 29, lohn Wiley and Sons, Chichester, 1986),5 % (temperate forests), and 7 % (boreal forests) of the total land surface of 149 M km2; if woodlands and brushlands with 6 % are included the forests altogether cover 29 % of the land surface. If deserts and ice covered land is subtracted (27 %) from the total surface area the relative coverage of the forests is 40 % ofthe vegetated land area. Important for the carbon cycle however, is the proportionally high er share of carbon in forests, both living biomass with 81 % (trop. 40 %, tempo 14 %, bor. 20 %, woodl. 7 % of a estimated total of 560 GtC) and soi! with 36 % (trop. 13 %, tempo 7 %, bor. 12 %, woodl. 4 % of an estimated total of 1 600 GtC). The forests of the tropical zone contribute 22 % of the net primary production, those of the temperate zone contribute 8 % as do the boreal forests, with remaining 6 % of the net primary production associated with the woodlands, adding up to 44 % ofthe estimated net primary production of 50 to 60 GtC/a.

Present global sink activity of the forests and the remaining vegetation If indeed the deforestation f1ux predominantly from the tropical zone is of the order of 1.6 Gt/a processes other than deforestation are responsible for a sink of carbon in the vegetation and soils of the same magnitude yet reversed sign. lt is somewhat difficult to divide this f1ux between forests on the one hand and the remaining vegetation on the other hand. From an equilibrium point of view the "missing carbon" should be distributed with the ratio of 560 to 1600 between 1iving vegetation and soils, that is 26 % to the vegetation and 74 % to the soils. As the forests contain 81 % of the biomass, their biomass share should be 21 % and as their soil carbon is 36 % of the total soil pool of 1600 Gt their contribution should be 27 %, adding up to a total of 48 % ofthe carbon pool.

Carbon Dioxide Mitigation in Forestry and Wood Industry XV

If we had used as a criterion the relative share in net primary production then 44 % of the additional carbon should be allocated to forests. On the other hand if we had used simply the biomass criterion as being the first pool where the carbon dioxide enters then up to 81 % should be allocated to forests. It therefore seems fair to say that using extremely simple criterion 44 % to 81 % could be taken up by forests.

Present sink activity of the great forest complexes of the world Workshop participants from different regions of the world reported contrastingly different sink or source functions of carbon for their horne lands. In one of the important classifications of forest with respect to wood use the two broad categories originally suggested by the F AO have been in use up to now, namely expIoitable and non-exploitable forests. We shall follow this distinction although more recently new categories have been suggested avoiding the word exploitation because it does not fit in the concept of sustainable development.

There are several criteria associated with exploitable forests:

l. they must not be protected by law Ce.g. national parks) 2. they must be accessab\e for transportation and 3. they should produce more than 1.5 m3/(ha a). Statistical data often refer only to

exploitable forests.

David Price and Mike Apps reported that the forests of Canada are presently a small source of carbon of the order of 60 MtC I a which is opposite to the mean trend between 1920 and 1979, when the same forests were a sink of about 150 MtC I a. The reversal was due to large devastations by fire and insect infestations within the last ten to 20 years. Europe is considered according to several sources (Kauppi) a sink of the order of 100 MtC / a , while for the boreal forests of the Former Soviet Union Anatolij Shvidenko reported values of a sink between 100 and 150 MtC / a. For the totality of temperate and boreal forests a sink of the order of 300 MtC / a can be calculated according to the ECE-F AO study on temperate forests, if only the tree biomass is taken into consideration. This figure could be doubled, if the ground vegetation as weil as the enrichment in soils are taken into consideration. For tropical forests there is much less in­formation on increments and fellings as in most countries forestry on a sustainable basis has not been established yet. However it is to be expected, that even in the tropics outside of the areas of deforestation carbon sequestration takes place. According to the theory of Farquhar and Kirschbaum the CO2 fertilization effect should be stronger in the tropics than in the temperate and boreal zones. A sink of the order of 0.5-1 GtC/a could be plausible.

XVI Editors' Summary Statement

Need for a clearinghouse between scientific institutions and politics The members of the workshop agreed that at least the methodology for carbon mitigation potentials through forestry and the wood industry has been developed in different countries of the world and is ready to be implemented. However, there is a need for a clearinghouse which describes the status quo with respect to the CO2

source and sink function of each economic sector. One branch of this clearing­house should deal with all actions planned with respect to forestry and wood industry in order to have unambiguous recommendations for policy makers. These national clearinghouses could then also communicate with complementary institutions in different countries of the world.

Potentials of carbon mitigation through forestry activities Because of the long lifetime of trees and forest ecosystems of decades to centuries the prediction of the future structure and function of forests will be strongly in­fluenced by the past history. The age class distribution for a given species is just one of the many parameters which need to be considered. There are in principal two mitigation strategies which need to be distinguished from each other, namely the carbon storage strategy in living forests and the maximum wood usage strategy to substitute for other high energy materials or fuels. While the first strategy holds considerable short term potentials to slow or offset the rate of carbon released to the atmosphere, its mitigation potential will saturate once the maximum storage is achieved. Therefore, in the long term the second strategy may be more important. However in order to achieve maximum carbon mitigationboth strategies should be combined.

Different strategies again have been identified that will increase the carbon storage in forests:

I. slowing deforestation, 2. increasing the area offorested land, 3. improved forest management techniques Ce.g. reduced impact logging, assisted

natural regeneration, enrichment planting), and 4. increasing forest productivity Ce.g. fertilization, choice of species or geno­

types).

Afforestation in different parts of the world is possible, however the potential new forest area has been overestimated in the past. Wolf gang Schopfhauser em­phasized that perhaps only 20 % of the area suitable for afforestation or refore­station is really available for planting trees because of competing land uses. This point was reemphasized also by a representative of the federal Ministry for Food, Agriculture and Forestry. According to Sigrid Strich the present sink activity of German forests offsets about 3 % of the emitted fossil fuel CO2 by industry, transportation and households, which is much less than for e.g. in Finland where Timo Karjalainen mentioned that the net growth of forests was able to sequester about half of the CO2 emissions from energy production and consumption in 1990.

Carbon Dioxide Mitigation in Forestry and Wood Industry XVII

Less than one percent could be achieved trough afforestation, while perhaps up to three percent could be achieved through additional use of fuelwood. Austria is more than 40 % covered by forests which can presently sequester approximately 13 % of the national emission budget through activities of forestry and wood industry. Even larger percentages are achieved in the Scandinavian countries Sweden and Finland.

Recommendation for an increase in the use of wood both for energy intensive structural materials and bioenergy There are several, in some cases country specific reasons for increasing the use of wood. First of all it should be pointed out, that in the developing countries of tropical Africa, Asia and America fuelwood is one of the main sources of energy. If forests are overharvested through this activity or if wood collection comes to such an intensity that new growth is impeded, fuelwood use is certainly a strategy which needs to be revised. In the industrialized countries the use of wood is often very different from country to country. Wood as a main building material is weil known in the United States, Canada, and Scandinavia. However it is less popular e.g. in central Europe. The use of fuelwood to a larger extent than at present was emphasised by the two Canadian participants as well as by the Austrian collegues. The point was made that a closer cooperation is needed between forestry and the fuelwood industry which designs power stations as efficient with wood as with conventional fossil fuels. All strategies which allow carbon mitigation with an economic incentive are better than carbon mitigation activities without immediate economic benefits. The reason for increased use of wood can also lie in the age structure of the forests; it was emphasised by Norbert Weber that some forests of Germany and of Europe are overaged and susceptable to natural disturbances much more than the younger forests. Cutting those forests and appling principles of new forestation could help ecologically and economically if the wood were brought to the market and if the markets were cleared by industry and households.

Socioeconomic development and the future of forests Any future prediction needs a careful assessment of the present status, both with respect to the state ofthe forests and the socioeconomic conditions. Key indicators of the forests are their area coverage and the fraction that is or could be used commercially, the species composition, the age class structure and the forest management regime, ranging from clear cutting to fuH sustainability. National statistics collected and evaluated by the F AO or other international organizations are complemented ever more frequently by remote sensing techniques which are less biased at least from the point of view of national interests. Philippe Mayaux from the Joint research centre of the European Commission in Ispra reported on the program: TREES - Tropical Ecosystem Environmental Observations by satellites, which has been applied to tropical Africa, Asia, and America. It showed that the area evaluated is in good agreement with the F AO data if in addition to the moist tropical forests of 1360 Mha (measured at present only by the pro gram

XVIII Editors' Summary Statement

TREES) the dry forests are included as weIl. The annual deforestation for the moist forests is 12 Mha for the 1981-1990 period (total annual tropical defore­station 15.4 Mha) with a percentage annual deforestation rate of 0.88 %. The reasons behind deforestation are of socioeconomic nature with the key factors being the need for additional agricultural land for a rising population, the need for export of timber as one of the cash crops and the present distribution of landownership. If the findings of the IPCC assessments are correct this net carbon flux from deforestation of the order of 1.6 GtC/a is compensated presently by a biospheric sink of the same magnitude. Any reductions of this flux will help to mitigate the carbon emissions. The FACE (Forests Absorbing Carbon dioxide Emissions) foundation of The Netherlands, e.g., have set out to install joint implementation projects where the industrial countries can offset their national emissions by tree plantations preferably on clear cut land which needs regeneration. Hans Verweij, director ofthe FACE foundation, reported on projects currently being implemented and managed in the tropical countries Uganda, Sabah-Malaysia and Ecuador but also in others, e.g. the Czech Republic and Poland.

The state of the temperate and boreal forests and particularly the fraction which is commecially used depend on the balance of the Net Annual Increment and the Net Annual Fellings. Despite the weil documented occurrences of air pollution on trees and forests in the neighbourhood or wider surroundings of pollution sources, the area averaged overall effect seems to be that the present rate of growth is higher than in the early part of the century. Arecent study of the European F orest Institute in Joensuu, Finland, show that the forest in Europe are growing faster than before ("Growth Trends in European Forests", European Forest Institute Report No. 5, H. Spiecker, K. Mielikainen, M.Köhl and J. Skovsgarde (eds.), Springer Verlag, 1996). Annual fellings both in Europe and in the Former Soviet Union are less than the net annual increment with the consequence that carbon is accumulated and the trees' age is increasing. The present timber market situation is not promoting increased cuts, on the contrary. Ideally, even from the point of carbon mitigation and forest stability, substitution ofwood for other high energy products is ideal because with greater harvests the overaged monocultures could be eventually replaced by mixed stands. In this workshop summary statement we point out that socioeconomic development both in the tropics and the temperate and boreal zone is more important for the present and near future (next thirty years), while the climate impacts may be lower in this first period and become predominant later on.

Climate change, CO2 increase and the future of forests in a coming greenhouse climate Forests respond not only to direct long term climate changes and short term fluctuations in precipitation and surface temperature but also to the changes in trace gases in the atmosphere. Aside from pollutants Iike S02 and NOx, it is mainly the slow but steady increase in the atmospheric CO2 concentration which changes

Carbon Dioxide Mitigation in Forestry and Wood Industry XIX

plant physiology, photosynthesis, Net Primary Production and Net Annual Increment. There is at present great uncertainty as to how the climate will develop regionally and how the forests of particular species composition will respond to the projected climate change. Models will help to provide insights in the future behaviour; nearly all models clearly point out that the combination of direct climate changes and CO2 increases must be taken into consideration at the same time. Christof Häger and Gundolf Kohlmaier pointed out that the consideration of the climate variables without the CO2 increase can lead to reduction of forest growth and in the worst case to a destruction of the present stands. However if the CO2 increase is considered at the same time the situation is much alleviated. On the contrary forest growth is increased due to the CO2 fertilization effect. Melvin Cannell pointed out that a careful nitrogen assessment will be necessary at the same time in order to predict the full development of the continued operation of the terrestrial carbon sink. David Price and Mike Apps emphasized that the future carbon balance will depend not only on the projected Net Annual Increment but rather more importantly on the concomittant change in the natural disturbance regimes, which destroy large parts of the Canadian forests periodically by great fires and insect infestations. Bernard Saugier stated that the observed growth in forests can be very weil documented with open top chamber experiments in which young beech or chestnut tree populations are examined under elevated CO2 levels. He emphasized that an acclimation effect, that is reducing growth to present con­ditions even under higher CO2 levels, is not observed if enough nutrients are available and root growth is not restricted by pots or other large root masses.

In a global analysis both the economic factors and the global changes in climate and CO2 need to be considered in integrated scenarios. Joseph Alcamo presented results of such studies obtained with the IMAGE II model. He pointed out in particular the competition for land use between forests and agriculturallands.

Conclusions and Recommendations

In the final discussion the members of the workshop agreed that although there are still many uncertainties inherent in data, analysis and assessment of C-pools and fluxes, the methodology for assessing C-mitigation potentials is developed and available and the range of the potentials and management options is of high con­fidence. In the short-term « 50 years) forestry planting and conservation are to be seen as important mitigation opportunities. In the long-term energy and material substitution by sustainably produced wood is the way to sequester greenhouse gas emissions in a sustainable way.

The workshop participants stressed the fact that forestry options do not re­present pure sequestration measures as forests fulfil a wide range of environmental and social functions, and enhanced management and afforestation can also be seen

XX Editors' Summary Statement

as a source to meet future timber demands. Some activities such as implementation of agroforestry, low impact logging or plantations on degraded land are win-win options anyway. lt must be emphasized that all activities are in the frame of a multifunctional forestry and sustainable development.

Needs for further research are seen with respect to the transient response of forests to changing climate and the energy and material substitution effects. Especially the potential for substituting energy expensive materials with wood has not been investigated enough.

The participants also mentioned the lack of scientifically based practical concepts for the implementation of global/regional sequestration programs taking into account socioeconomic conditions. Because the driving forces of deforestation and reforestation are outside the forestry sector, a consensus of all groups involved with management of forests and future use of degradated areas or abandoned agricultural lands are aprerequisite for the successful implementation of forestry mitigation pro grams.

G. H. Kohlmaier Frankfurt Germany

M Weber Munich Germany

R. A. Houghton Woods Hole USA

List of Contents

Chapter 1 Forest Resources: Past, Present and Future Role of Managed and Unmanaged Forests in the Global Carbon Balance .............. 1

l.l Historie Role ofForests in the Global Carbon Cycle ................................... 1 R.A. Houghton

1.2 The History and Future Dynamies of Carbon Sequestration in Finland's Forest Sector ............................................................................... 25 T. Karjalainen, A. Pussinen, S. Kellomäki, R. Mäkipää

1.3 Dynamies ofForest Resourees ofthe Former Soviet Union with Respeet to the Carbon Budget ................................................................... .43 A. Shvidenko, S. Nilsson

1.4 Past and Possible Future Carbon Dynamies ofCanada's Boreal Forest Eeosystems ........................................................................... 63 D.T. Price, M.J. Apps, W.A. Kurz

1.5 Assessment ofHumid Tropical Forest Distribution and Conditions Using Remote Sensing at a Global Seale .................................................... 89 Ph. Mayaux, F. Aehard, J.-P. Malingreau

Chapter 2 Implementation of Carbon Dioxide Mitigation Measures in Forestry and Wood Industry on aNational and International Scale ...................................................................... 111

2.1 Analysis and Potential for Mitigation Options .......................................... 111 F. Schafhausen

2.2 Carbon Mitigation Potential of German Forestry Considering Competing Forms ofLand Use ................................................................. 125 S. Strich

2.3 Present and Future Options of Forests and Forestry for COrMitigation in Germany ...................................................................... 137 K. Böswald

2.4 Afforestation in Europe: Experienees and Future Possibilities ................. 153 N. Weber

XXII List of Contents

2.5 Implementing Carbon Mitigation Measures in the Forestry Sector - a Review ....................................................................... 167 M. Lindner

Chapter 3 Quantitative and Qualitative Evaluation of Carbon Dioxide Mitigation in Forestry and Wood Industry .............................. 185

3.1 W orld F orests: The Area for Afforestation and their Potential for Fossil Carbon Sequestration and Substitution .......................................... 185 W. Schopthauser

3.2 Substitution ofWood from Plantation Forestry for Wood from Deforestation: Modelling the Effects on Carbon Storage ......................... 205 B. Schlamadinger, G. Marland

3.3 Life Cycle Assessment ofWood Products ................................................ 219 K. Richter

3.4 The Face Foundation ................................................................................ 249 H. Verweij

3.5 Climate Stabilisation and Conservation ofBiodiversity-Two Goals - One Way? ............................................................................ 257 J.H. Reichholf

Chapter 4 Forestry Mitigation Options under Future Climate Change and Socioeconomic Pressures ..................................................... 269

4.1 Future Development ofthe Carbon Cycle: The Role ofthe BiotaIForests within the IPCC Stabilisation Scenarios ................................................... 269 G.H. Kohlmaier, Ch. Häger, F. 1ft, G. Würth, F. Joos, M. Bruno

4.2 The Frankfurt Biosphere Model (FBM): Regional Validation Using German Forest Yield Tables and Iventory Data and Extrapolation to a 2xC02 Climate ................................................................................... 293 G. Würth, Ch. Häger, G.H. Kohlmaier

4.3 The Direct Effect of CO2 Enrichment on the Growth of Trees and Forests ...................................................................................... 323 B.Saugier, M. Mousseau

4.4 Ecosystem Properties and the Continued Operation ofthe Terrestrial Carbon Sink ............................................................................ 3 41 M.G.R. Cannell

4.5 The Distribution ofFuture Global Forests as Affected by Changing Climate and Land Use .............................................................. 353 E.Kreileman, J. Alcamo

List of Contributors

Achard, Frederic, Dr. Institute for Remote Sensing Applications Monitoring Tropical Vegetation Unit, Joint Research Center 21020 Ispra, Varese, Italy Phone +39-332785545/9822 Fax +39-332 879073

AIcamo, Joseph, Prof. Dr. Center for Environmental Systems Research, University ofKassel Kurt-WoIters-Str. 3, 34109 Kassel, Germany Phone +49-561 804 3898/223113266 Fax +49-561 804 3176 e-mail: aIcamo@usf.uni-kassel.de

Apps, Mike, Dr. Canadian Forest Service Climate Change, Northern Forestry Centre 5320-122 Street, Edmonton, Alberta T6H 3S5, Canada Phone 001-4034357210 Fax: 001-403 435 7359 e-mail: mapps@NOFC.Forestry.CA or International Institute for Applied System Analysis IIASA Schloßplatz I, 2361 Laxenburg, Austria Phone +43-2236 807 229/357 Fax +43-2236 71313

Böswald, Klaus, Dr. Institute of Forest Policy, University of Freiburg Bertoldstr. 17, 79085 Freiburg, Germany Phone +49-761 203 3723 Fax +49-761 203 3705

Bruno, Michael, Dr. Institute of Physics, University of Bem Sidlerstr. 5, 3012 Bem, Switzerland Phone +4 I -31-63 I 861 I Fax +4 I -31-631 4405

XXIV List ofContributors

CannelI, Melvin, Prof. ITE Bush Estate, Penicuik Midlothian, EH26 OQB, Great Britain Phone +44-131 445 4343 Fax +44-131 4453943 e-mail: mgre@ite.ac.uk

Fritz, Hubert Bau Fritz GmbH Alpenstraße 25 87746 Erkheim Phone 08336/9000

Häger, Christof, Dipl.-Phys. Institute for Physical and Theoretical Chemistry University ofFrankfurt Marie-Curie-Straße 11,60439 Frankfurt a.M., Germany Phone +49-69-798 29431/16 Fax +49-69-798 29445 e-mail: haeger@chemie.uni-frankfurt.de

Houghton, Richard A., Dr. Dr. h.c. Woods Hole Research Center 13 Church Street, P.O. Box 296, Woods Hole, Mass. 02543, USA Phone 001-508 5409900 Fax 001-508 5409700 e-mail: rhoughton@whrc.org

1ft, Frank, Dip!. Chem. Institute for Physical and Theoretical Chemistry University ofFrankfurt Marie-Curie-Straße 11,60439 Frankfurt a.M., Germany Phone +49-69-798 29431/16 Fax +49-69-798 29445

Joos, Fortunat, Dr. Institute of Physics, University ofBern Sidlerstr. 5,3012 Bern, Switzerland

Karjalainen, Timo, Senior research er European Forest Institute Torikatu 34, FIN-80100 Joensuu, Finland Phone +358-13-252020 Fax +358-13-124393 e-mail: timo.karjalainen@efijoensuu.fi

Carbon Dioxide Mitigation in Forestry and Wood Industry XXV

Kassube, Andreas, Cand.Chem. Inst. for Physical Chemistry and Scientific Center of Environmental Studies Goethe-Universität Frankfurt am Main Marie-Curie-Straße 11 D-60439 Frankfurt a. Main Phone +49-69-798 29416 Fax +49-69-798 29445 e-mail: kassube@chemie.uni-frankfurt.de

Kellomäki, Seppo, Dr. Fakulty ofForestry, University of Joensuu P.O. Box 111, 80101 Joensuu, Finland

Kohlmaier, GundolfH., Prof. Dr. Institute far Physical and Theoretical Chemistry University of Frankfurt Marie-Curie-Straße 11,60439 Frankfurt, Germany Phone +49-69-798 29432/16 Fax +49-69-798 29445 e-mail: G.Kohlmaier@chemie.uni-frankfurt.de

Krei\eman, Eric, Dr. National Institute ofPublic Health and Environment, the Netherlands (RIVM) P.O. Box 1,3720 BA Bilthoven, The Netherlands

Kurz, Werner A., Dr. ESSA Technologies Ud., 1765 West 8th Avenue, Vancouver, BC V6J 5C6, Canada

Lindner, Marcus, Dipl.-Forstwirt Dept. of Global Change and Natural Systems Potsdam Institute for Climate Impact Research (PIK) Telegraphenberg, P.O.Box 60 1203, 14412 Potsdam, Germany Phone +49-331 2781 147 Fax +49-331 2781 204 e-mail: lindner@pik-potsdam.de

Mäkipää, Raisa, Dr. The Finnish Farest Research Institute, P.O. Box 18,01301 Vantaa, Finland

Malingreau, Jean, Dr. Institute for Remote Sensing Applications Monitoring Tropical Vegetation Unit, Joint Research Center 21020 Ispra, Varese, Italy Phone +39332785545/9822 Fax +39 332 879073

XXVI List of Contributors

Mariand, Gregg, Dr. Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335, U.S.A.

Mayaux, Philippe, Dr. Institute for Remote Sensing Applications Monitoring Tropical Vegetation Unit, Joint Research Center 21020 Ispra, Varese, Italy Phone +39-332785545/9822 Fax +39-332879073 e-mail: philippe.mayaux@jrc.it

Mousseau, Marianne, Dr. Laboratoire d'Ecophysiologie Vegetale, Universite Paris Sud, Bat 362, 91405 Orsay cedex, France Phone +33-1 6941 7961 Fax +33-1 6941 7238

Nilsson, Sten, Dr. International Institute for Applied System Analysis IIASA Schloßplatz 1, 2361 Laxenburg, Austria Phone +43-2236 807 229/357 Fax +43-223671313 e-mail: nilsson@iiasa.ac.at

Price, David T., Dr. Canadian Forest Service, Northern Forestry Center 5320-122 Street, Edmonton, Alberta T6H 3S5, Canada Phone 001-4034357210 Fax 001-4034357359 e-mail: dprice@NOFC.Forestry.CA

Pussinen, Ari, Dr. Fakulty of Forestry, University of Joensuu P.O. Box 111,80101 Joensuu, Finland

Reichholf, JosefH., Prof. Dr. Zoological State Collection Münchhausenstr. 21, 81247 München, Germany Phone +49-898107 123 Fax +49-89 8107 123

Richter, Klaus, Dr. Eidg. Materialprüfungs- u. Forschungsanstalt (EMPA) Überlandstr. 129,8600 Dübendorf, Switzerland Phone +41-18235511 Fax +41-18216244 email: klaus.richter@empa.ch

earbon Dioxide Mitigation in Forestry and Wood Industry

Saugier, Bernard, Prof. Dr. Laboratoire d'Ecophysiologie Vegetale, Universite Paris Sud, Bat 362, 91405 Orsay cedex, France Phone +33-1 6941 7961

Fax +33-16941 7238 email: Bernard.Saugier@eco.u-psud.fr

Schafhausen, Franzjosef, MR, Dipl.-Volksw., Dipl.-Betriebsw. Federal Ministry for Environment, Nature Conservation and Nuclear Safety

AG G 16 P.O. Box 120629,53048 Bonn, Germany Phone +49-228-305-2350/2354

Fax +49-28-305-3336/3524

Schlamadinger, Bernhard, Dr. Joanneum Research Forschungsgesellschaft Elisabethstr. 11, 8010 Graz, Austria Phone +43-316 876 340 Fax +43-316 876 320 e-mail: schlamadinge@pbox.joanneum.ac.at

Schopfhauser, Wolfgang, Dr. Confederation of European Paper Industries 306 Avenue Louise,

B- I 050 Brussels Phone +32-2-672 49 1 I Fax +32-2-646 8137 e-mail: W.schopfhauser@cepi.org

Shvidenko, Anatoly, Dr.

International Institute for Applied System Analysis IIASA Schloßplatz I, 2361 Laxenburg, Austria Phone +43-2236807229/357 Fax +43-2236 71313 e-mail: nilsson@iiasa.ac.at

Strehler, Arno, Dr. Landesanstalt flir Landtechnik V öttinger Str. 36 85354 Freising

Phone 08161171 3303 Fax 081611713527 e-mail: str_sek@ban.tec.agrar.tu-muenchen.de

XXVII

XXVIII List of Contributors

Strich, Sigrid, Dipl.-Forstw. Federal Ministry for Food, Agriculture and Forestry Rochusstr. 1, 53123 Bonn, Germany Phone +49-228 529-3140 Fax +49-228 529-4262 as of 7th Aug. 1996: Ensfeld 4, 79801 Hohentengen a. H., Germany Phone +49-7742-7310

Verweij, Hans, Dr. FACE Foundation Utrechtsweg 310, P.O. Box 575, 6800 AN Amhem, The Netherlands Phone +31-26-372-1631 Fax +31-26-161311165 e-mail: face@facefoundation.nl

Weber, Michael, Dr. Institute of Silviculture and Forest Management, University of Munich Am Hochanger 13 85354 Freising Phone +49-8161-714689 Fax +49-8161-714616 e-mail: weber@wbte.forst.uni-muenchen.de

Weber, Norbert, Dr. Institute ofForest Policy, University ofFreiburg Bertoldstr. 17, 79085 Freiburg, Germany Phone+49-761 2033716 Fax +49-761 203 3705

Weyers, Susanne, Dipl. Geogr. Bundesforschungsanstalt flir Forst- und Holzwirtschaft Leuschnerstr. 91 21031 Hamburg

Wisniewski, Joe, Dr. PO Box 1291 McLean. VA 22101 USA Phone 001 703 5343005 Fax 001 7035340462

Würth, Gudrun, Dipl.-Biol. Institute for Physical and Theoretical Chemistry Marie-Curie-Straße 11,60439 Frankfurt a.M., Germany Phone +49-69-798 29430116 Fax +49-69-798 29445 e-mail: @chemie.uni-frankfurt.de

Carbon Dioxide Mitigation in Forestry and Wood Industry XXIX

List of interna I and external reviewers

internal reviewers

Apps, Mike, Canada

Böswald, Klaus, Gerrnany

CannelI, Melvin, United Kingdom

Houghton, Richard A., USA

Karjalainen, Timo, Finland

Kohlmaier, Gundolf, Gerrnany

Lindner, Marcus, Gerrnany

Price, David, Canada

Saugier, Bernard, France

Schlamadinger, Bernhard, Austria

Shvidenko, Anatoly, Russia

Strich, Sigrid, Germany

Verweij, Hans, Netherlands

Weber, Michael, Germany

external reviewers

Brown, Sandra, USA

Dedieu, Gerard, France

Dixon, Robert, USA

Erikson, Hillevi, Sweden

Field, Christopher, USA

Friend, Andrew, United Kingdom

Hall, David, United Kingdom

Kauppi, Pekka, Finland

Klöpffer, Walter, Gerrnany

Marutzky, Rainer, Germany

Mohren, G. M. 1., Netherlands

Nabuurs, G. 1., Netherlands

Norby, Richard, USA

Jonas, Matthias, Austria

Polley, Heino, Gerrnany

Robson, David, Netherlands

Schwoerer-Böhning, Matthias, Germany

Spitzer, Josef, Austria

Woodwell, George, USA