Protection of the cultural heritage of the forest – an interactive decision support system
Sverker Johansson (project leader)
Summary of results from Uppsala Science Park, www.kunskapdirekt.se/kulturarv
Email: sverker.johansson@skogforsk.se
Profitable forestry is essential for a flourishing countryside and a competitive forestry industry. At the same time, forestry operations must not damage other interests. There is sometimes a risk that archaeological relics and other cultural remains may be damaged during harvesting and scarification. Opinions differ regarding the scope of such damage. In surveys conducted by the National Board of Forestry and the National Heritage Board, the proportion of damaged ancient monuments and environments rich in cultural heritage, after forestry operations, has varied between 20% and 80% during the last century.
In order that the forestry industry may be able to avoid damage to cultural remains during its operations, it is essential that these should be known, either through map material or through knowledge of the historical remains. It is not only a matter of avoiding archaeological remains. Active management is just as often necessary. The sites of old smallholdings or driveways must be cleared so that the remains do not disappear.
Through this project, the new web based consultative tool "Cultural heritage of the forest" has been produced. The tool is part of the Skogforsk knowledge portal Knowledge Direct and is intended in the first place for forest owners, their advisers and the contractors who will work in the forest. The information is also useful for the authorities and the general public since it puts archaeological and cultural remains into a forest context.
The contents have been updated and extended with photographs and text and film sequences. In the web tool there is information on why it is important to conserve cultural environments, legislation, cultural remains in different landscapes, guidelines for forest operations and examples of best practice in cultural-rich environments. All the pages can also be printed directly or transferred to pdf files for use as course literature or as reference material in the field.
Management of pine stands infected by Gremmeniella abietina
Andreas Bernhold (project leader)
Summary of results with list of publications from Forest Ecology and Management, SLU.
Email: Andreas.Bernhold@ssko.slu.se
Parasitic fungi are a threat to Swedish pine.
The parasitic fungus Gremmeniella abietina (GA) is one of the most serious pests of pines in Sweden. The fungus infects and kills the young shoots and buds of the trees, which can result in mortality or reduced vitality, and secondary insect attacks. The hitherto most serious GA outbreak in Sweden occurred in 2001, and in three years almost 500,000 ha of middle-aged pine forest were damaged. The cost to the forest industry for remediation and loss of income was estimated to exceed SEK 1000m.
Since the state of knowledge regarding management of infected stands was low at the time of the outbreak, the aim of this project was to perform studies of practical applicability as the basis for designing management methods for stands damaged by GA. The issues to be dealt with were: How long does GA survive and reproduce in infected logging residues? How extensive will damage be when planting takes place directly after remediation felling and what is the effect of brushwood clearance? What proportion of needle loss do trees survive, and what will be the effects on growth and the risk of secondary insect attack? Is lodgepole pine (Pinus contorta) more resistant than Scots pine (Pinus sylvestris) to GA of the large tree type (LTT)?
The results show, inter alia, that if damaged stands are regenerated within two years of remediation felling, removal of infected felling waste can reduce the number of damaged plants by up to 50%. In order to secure the survival of individual trees, remediation thinning of trees with at least 75-80% needle loss due to GA is recommended. Remediation thinning should be carried out already during the first winter after symptoms with red needles appear, in order to prevent damage to trees by pine shoot beetle (Tomicus piniperda) and blue stain fungi. Lodgepole pine seedlings are more resistant to GA (LTT) than Scots pine seedlings, in terms of survival, length of infected tissue and recovery.
The most recent studies have been published as follows:
Bernhold A., Hansson P., Rioux D., Simard M., Laflamme G. 2009. Resistance to Gremmeniella abietina (European race, large tree type) in introduced Pinus contorta and native Pinus sylvestris in Sweden.
Canadian Journal of Forest Research, vol 39, 89-96
Reference to thesis in 2008 which includes the study.
Bernhold A. 2008. Management of Pinus sylvestris stands infected by Gremmeniella abietina: aspects of tree survival, growth and regeneration after the severe outbreak in 2001.
Acta Universitatis Agriculturae Sueciae, nO 2008:27
The role of different microorganisms in the degradation of chitin and fungal mycelium in forest soil
Björn Lindahl (project leader)
Summary of results from Forest Ecology and Pathology, SLU
Email: bjorn.lindahl@mykopat.slu.se
Microbial communities in boreal forest soil are dominated by fungi, and large quantities of nutrients are immobilised in fungal mycelium. The question is what happens to these nutrients when the fungal mycelium is degraded? The principal hypothesis of this project is that the identity of the mycelium degrading organisms is of critical importance for the fate of these nutrients. If the mycelium is degraded by decomposer fungi with good access to carbon and energy-rich litter material, the mycelium nitrogen is expected to remain locked up in the fungal biomass. If, on the other hand, the mycelium is degraded by symbiotic mycorrhizal fungi, the nitrogen becomes available to their host plants without mineralisation. If it is instead degraded by energy-limited bacteria or micro- fungi, mineralisation and release of ammonium may be expected.
The original plan was to use, as marker, the expression level of a group of genes which code for an enzyme involved in the degradation of fungal cell walls. It was intended to spend a large proportion of the project in mapping the evolution of this gene family in various fungal and bacterial groups, and then to investigate how different disturbances affect the balance between different mycelium degrading groups and the consequences of this for nitrogen cycling.
Microbial processes have traditionally been studied in isolated soil samples after the roots had been severed from the trees and even removed. The results of such studies must however be interpreted with great care. When contact with the living tree is disrupted, this results in drastic changes in the structure of the microbial community, with major functional consequences. This study demonstrates that important ecological processes, e.g. ammonium production, may be attributed to quantitative changes in specific microbial groups. Functional subgroups of microorganisms must therefore be taken into consideration in modelling for carbon and nutrient cycling in forest soil in order to avoid serious fundamental errors.
Changes in lignin content in poplar
Gunnar Wingsle (project leader)
Summary of results with list of publications from SLU
Email: Gunnar.Wingsle@genfys.slu.se
The objective of a collaborative project with Sida and SAREC is to produce new knowledge of how, with biotechnological methods, the wood structure in trees can be changed. India imports large quantities of industrial wood raw material every year. Since this import is rapidly increasing, it is of the utmost importance that India should endeavour to become self-supporting, mainly in relation to pulp and paper. One way may be to develop and increase biomass production for domestic products.
The principal aim of this project is to modify the quantity of lignin in wood by biotechnological methods. Lignin is one of the most abundant natural polymers in the world and it has a major role as a water repellent component, which makes it possible to transport water in the vascular tissues of the plant. However, high lignin contents have negative effects. In the chemical processes in paper manufacture to remove lignin from the cellulose fibres, a lot of energy is used and the method produces large quantities of environmentally damaging substances. On the other hand, the lignin content itself has a high energy value which can be used in producing energy.
Experiments have been made to modify the lignin content of poplar with specific regulatory proteins which affect the biosynthesis of lignin. The proteins studied are transcription factors which can regulate several or single enzymes that are important for the content and composition of lignin. Another type of enzyme (superoxide dismutase), which affects the content of specific substrates for lignin production, has also been used in the study. The project is to be regarded as a first stage in a long process which will ultimately be able to regulate and control biosynthesis pathways for the creation of transgenic trees as an alternative to forest improvement.