Timo Karjalainen

Forest carbon sequestration and harvests in Scots pine stand under different climate and nitrogen deposition scenarios

Abstract In this study, effects of altered rotation length, nitrogen deposition and changing climate on harvest removal and carbon sequestration of forest, as well as on economic profitability of forestry, were assessed. This study was based on simulations with a gap-type forest succession model in the conditions that represent Scots pine stands in southern Finland. Both warmer climatic conditions and increased nitrogen deposition enhanced forest productivity and timber yield. This also shortened the optimum rotations based on mean annual yield and soil expectation value. The highest carbon stock in forests, i.e. the highest mean annual carbon stock in the forest over a rotation period, was achieved with long rotations and higher nitrogen deposition. However, a warmer climate had an opposite effect on the forest carbon stock, because enhanced decomposition of soil organic matter resulted in a lower carbon stock in the forest soil.

Project-based greenhouse-gas accounting: guiding principles with a focus on baselines and additionality

Project-based Greenhouse Gas Accounting : guiding principles with a focus on baselines and additionality

Trees as carbon sinks and sources in the European Union

The carbon (C) sinks and sources of trees that may be accounted for under Article 3.3 of the Kyoto Protocol during the first commitment period from 2008 to 2012 were estimated for the countries of the European Union (EU) based on existing forest inventory data. Two sets of definitions for the accounted activities, aAorestation, reforestation and deforestation, were applied. Applying the definitions by the Food and Agricultural Organization of the United Nations (FAO), the trees were estimated to be a C source in eight and a C sink in seven countries, and in the whole EU a C source of 5.4 Tg year ˇ1 . Applying the definitions by the Intergovernmental Panel of Climate Change (IPCC), the trees were estimated to be a C source in three and a C sink in 12 countries, and in the whole EU a C sink of 0.1 Tg year ˇ1 . These estimates are small compared with the C sink of trees in all EU forests, 63 Tg year ˇ1 , the anthropogenic CO2 emissions of the EU, 880 Tg C year ˇ1 , and the reduction target of the CO2 emissions, 8%. In individual countries, the estimated C sink of the trees accounted for under Article 3.3 was at largest 8% and the C source 12% compared with the CO2 emissions. 7 2000 Elsevier Science Ltd. All rights reserved.

Integrated forestry assessments for climate change impacts

Forests and the forest sector are sensitive to climate change at greatly varying scales. The complexity of the interactions among the physical environment, forest growth, the management and utilisation of forest resources, and market responses has stimulated efforts to model the impact of global changes on the forest sector by linking impact models developed from different disciplines. This paper reviews existing experiences in integrated forest sector impact assessments. Different ways of integrating cross-disciplinary impact assessments are classified as linking, coupling and integrated modelling. To date the most common method is a “one-way” linking, where results from one model are used as input to a different model. When different impact models are coupled, feedbacks can be analysed, e.g. between ecological and economic systems. Integrated modelling is described as a third step, where different sub-models are embedded into a common model framework. The concept of balance is introduced as a key to successful integration of different disciplines in integrated assessment (IA) studies. The review of existing experiences emphasises the problem of complexity and the need to simplify disciplinary approaches. It also illustrates how methodologies applied to forest sector IA studies have evolved over the last few years. Several scaling issues that are particularly important for IA modelling in forestry are discussed, including the consequences of heterogeneity in site conditions, the variable influence of extreme events on ecosystems and on the economic sector, and the differences in temporal and spatial scales over which key forest growth and renewal processes operate. Climate impact assessments include uncertainties. Some common sources of uncertainty in forest IA modelling are outlined, and methods that have been used to address this uncertainty are reviewed. We discuss the policy relevance of integrated impact assessments and stress the importance of stakeholder involvement in IA projects. The paper concludes with some recommendations for future developments in this relatively new field of research.

Scenarios for the carbon balance of Finnish forests and wood products

Abstract The objective of this paper is to compare different scenarios for carbon (C) sequestration in the forest sector in Finland. Forest inventory data was used as input data to simulate the dynamics of C sequestration with a gap-type forest simulation model and a wood product model. In the baseline scenario, current forest management practices were applied. In another scenario, current recommendations for forest management were applied, which resulted in more intensive harvesting than in the baseline scenario. Both scenarios were also applied under changing climatic conditions to demonstrate the possible effect of climate change on C sequestration. This study demonstrates that C sequestration assessments should include not only C in the biomass of trees, but also C in the soil and in the wood products, as well as interactions between the respective pools. Partial assessments are likely to result in misleading estimates of the actual C sequestration. Forest management affects the distribution of C between the pools and the changing climate is likely to change this distribution. The Kyoto Protocol deals with only a limited part of the forestry and forest C cycle and C accounting accordingly can provide results that depart substantially from more complete accounting.

Potential contribution of the forest sector to carbon sequestration in Finland

Abstract Although Finlands forest resources have been utilized intensively, the size of the total volume of the growing stock has increased since the mid-1960s, and hence increasing amounts of carbon have been sequestered by forests. The net sequestration by forests has also been substantial when compared with the CO 2 emissions resulting from energy generation and consumption based on fossil fuels and peat. It is also important, from the point of view of mitigating the effects of climate change, to assess how the sequestration capacity of forests may change under changing climatic conditions. This paper presents the results of a study assessing the development of the forest and wood-product carbon budget for Finland, based on regionally measured data, detailed dynamic models, and recent predictions concerning the changing climate. At the starting point for the simulation (1990), nearly 90% of the forest sectors carbon storage was found in the forest. Regular management transferred carbon from forests to wood products. Under the current climatic conditions, the simulated forest carbon storage increased 45% by the year 2100, and the wood-product storage by 320%, as a consequence of continuous production. Under changing climate conditions, the forest carbon storage increased, but started to decline when the temperature increase exceeded 2.5°C within 40 years.

A generalised approach of accounting for biospheric carbon stock changes under the Kyoto Protocol

Abstract The Kyoto Protocol aims to reduce net emissions of greenhouse gases to the atmosphere by various measures including through management of the biosphere. However, the wording that has been adopted may be difficult and costly to implement, and may ultimately make it impossible to cost-effectively include biosphere management to reduce net greenhouse gas emissions. An alternative scheme is proposed here, especially for the second and subsequent commitment periods, to more effectively deal with the anthropogenic component of carbon stock changes in the biosphere. It would categorise the terrestrial biosphere into different land-use types, with each one having a characteristic average carbon density determined by land-use and environmental factors. Each transition from one land-use type to another, or a change in average carbon density within a specified type due to changed management would be defined as anthropogenic and credited or debited to the responsible nation. To calculate annual credits and/or debits, the change in average carbon stocks must be divided by a time constant which would either be a characteristic of each possible land-use conversion, or applicable to the sum of changes to a nations biospheric carbon stocks. We believe that this scheme would be simpler and less expensive to implement than one based on the measurement of actual carbon changes from all specified areas of land. It would also avoid undue credits or debits, because they would only accrue as a result of identified anthropogenic components of biospheric carbon changes whereas carbon fluxes that are due to natural variation would not be credited or debited.

Effects of nitrogen fertilization on carbon accumulation in boreal forests: Model computations compared with the results of long-term fertilization experiments

Abstract Computations with a gap-type forest simulation model indicate that net primary production increased by 20% in a mesic site and 44% in a dry site due to an increased nitrogen input of 600–750 kg N/ha over a 26- to 30-year period. In addition to enhanced carbon sequestration by the vegetation, the nitrogen input increased carbon storage in the litter and humus layers. The results of these model computations were similar to those of the long-term field experiments. Thus, it can be assumed that the model can be used for assessing the effect of nitrogen input on the biomass production and carbon balance of forest ecosystems.

Carbon Sequestration in the Forest Sector under Climate Change: Upscaling from the Plot Level to the European Forests Level

European forests play a significant role in the global carbon cycle. At present the difference between growth and harvest of the whole tree biomass is 100 Tg C yr−1. Their future role is, however, uncertain because a large proportion of the forests is maturing and the effects of climate change are uncertain at the European scale. By utilising scattered knowledge on the effects of climate change from experiments, process based models, and gap-type models, and bringing that information into a large scale forestry scenario model for European forests, a suitable methodology for upscaling can be developed. Then, the future carbon balance of European forests under climate change can be assessed. This paper describes the kind of information which may be derived from plot level models and the methodology for incorporating of the effects of climate change at the European level.

Sequestration of carbon in the Finnish boreal forest ecosystem managed for timber production

The increasing concentration of carbon dioxide (CO2) in the atmosphere alone contributes by over 50% to the enhancing greenhouse effect (Houghton et al. 1990, 1992). The major anthropogenic sources of carbon (C) entering the atmosphere are combustion of fossil fuels and land-use changes. Enhancement of the greenhouse effect can be mitigated by decreasing the emission of C or by increasing the capacity of terrestrial C sinks. Terrestrial C sinks can, in turn, be strengthened by increasing the C in vegetation or soil on the current land area or by increasing the area covered by vegetation. In this context, the role of forest ecosystems is crucial, since they occupy one third of the Earth’ land area and contain approximately 45% of the total terrestrial C (915 Pg C of 2050 Pg C) (Bolin 1986; Houghton et al. 1990).