260 likes | 273 Views
CLOSE TO NATURE FORESTRY. International Seminar Zvolen 2003. Methods and Procedures of Forest Management Planning in Close to Nature Forestry and Its Ecological Impacts Heinrich Spiecker, Institute of Forest Growth, Freiburg. Three Principles of Close to Nature Forest Management.
E N D
CLOSE TO NATURE FORESTRY International Seminar Zvolen 2003 Methods and Proceduresof Forest Management Planningin Close to Nature Forestryand Its Ecological ImpactsHeinrich Spiecker, Institute of Forest Growth, Freiburg
Three Principles of Close toNature Forest Management Tree species composition: native and site adequate species Forest structure:ecological stability, biodiversity Management:application of self-regulating processes
Management Conditions State of the ForestMany Forests have not been managed according to the principle of “close to nature forestry”!History: Forest devastation, afforestation…..not always site adequate species, even aged stands,low stability (snow, storm, drought, insects, fungi) KnowledgeExperience and knowledge on “Close to NatureForestry” and its impacts on ecological values is limited Conditions are changing:socio-economic conditions and ecological conditions
Two types of “Close to Nature Forest Management” A. Many forests needed to be converted when applying the criteria of “Close to Nature Management”: A management of Conversion is needed. B. Management of “Close to Nature Forests”
today 'natural' Tree species distribution in Central Europe % 100 Abies alba Picea abies Pinus sp. 80 other broadleaved sp. Quercus sp. Fagus sylvatica 60 20 40 10 0 20 -10 -20 0 source: Mayer 1984 Close to nature forestry: more broadleaved trees
40 20 0 2000 1960 1970 1980 1990 20 0 2000 1960 1970 1980 1990
To provide a solid base for management planning related to close to nature management contributions of various disciplines are needed: Understanding of History Inventory: sites, species, stand structure Ecology: Ecological values such as ecological risk, soil fertility, biodiversity, water quality Silviculture Forest Operations Policy Economy
Where should close to nature forestry be applied? - Site conditions • Special values: protection of habitats, erosion, water quality - Stand/landscape conditions - ecological risks - economic expectations of the owner - political conditions: incentives, restrictions
What options for management towards close to nature forestry exist? - clear cut - shelter-wood cut
Some prerequisites of close to nature forestry on management activities: • work and machinery input
Prerequisites of close to nature forestry on management activities: • work and machinery input - quality of work - information and education
Prerequisites of close to nature forestry on management activities: • work and machinery input - quality of work - education and information - infrastructure - game density
What are the results of close to nature forestry: Ecological aspects • ecological risk
What are the results of close to nature forestry: Ecological aspects • ecological risk - long-term site fertility (nutrient cycling etc.) - biodiversity - water quality
Ecological Impact of Close to Nature Forestry Nutrient balance in conifer forests: often higher acidification nutrient cycling is slowed down accumulation of organic matter In conifer Forests Susceptibility to windthrow snow damage bark beetles fungi is relatively high
Ecological Impact of Close to Nature Forestry Biodiversity in conifer forests: less diversity in pure coniferous forests is a generally accepted hypothesis Water quality in conifer forests: higher acidity in surface water transpiration rate is lower while interception is higher
What are the results of close to nature forestry: Ecological aspects • ecological risk - long-term site fertility (nutrient cycling etc.) - biodiversity - water quality Economic aspects - cost of managing (harvesting etc.) - wood characteristics
Economic Impact of Close to Nature Forestry Criteria: - net present value (profitability) • cash flow (liquidity) - risk • flexibility Relevant impacts: - wood quantity - wood dimension and quality - length of the production period - establishment, tending and harvesting cost
Conclusions I The choice of the management option depends on: - site conditions, stand conditions, etc. - ownership - economic conditions - political conditions No one single optimal management option!
Conclusions II As management has long-term impacts we have to deal with - changing economic conditions - changing ecologic conditions - changing values - changing political conditions - improvement of knowledge/technologies
Conclusions III Uncertainty: Management strategies need to be flexible! Strategies should allow various options for the future