challenges diaci2

Close-to-Nature Forestry: linking ecological, economical and social values

by Jurij DiaciBiotechnical Faculty University of Ljubljana, Slovenia Department for Forestry and Renewable Forest Resources

Jurij Diaci

Close-to-nature forestry: linking ecological, economical and

social values

University of Ljubljana, Biotechnical FacultyDepartment for Forestry and Renewable Forest ResourcesSlovenia

1. Origins of close-to-nature forestry (CTN)2. Natural processes and CTN3. How does CTN silviculture operate?4. Economic aspects of CTN5. Social aspects of CTN6. Conclusions

Landslides and erosion in Japan and intensive reforestations

1. Origins of close-to-nature silviculture

Degraded landscapes across the Alps with erosion etc.

Afforestation on Karst (Slovenia) in 1895Afforestation on Karst (Slovenia) in 1895

Joseph Ressel: Joseph Ressel: started afforestationstarted afforestationss on Karst, also on Karst, also inventor of ships inventor of ships propellerpropeller

- huge natural interconnected forest- high species diversity due to glacial refugia- many umbrella species (e.g. bear, lynx,

wolf, peregrine falcon)- many old-growth forests

Selection mixed silver fir beech forests on Zlatibor (Srbija)

Selection forests as a tradition within whole Dinaric Mountains

F. de Liocourt:

De l’amenagement des sapinières. Bulletin trimestriel, Société forestière de Franche-Comté et Belfort, juillet 1898, pp. 396 – 409.

Henry Biolley (1858 -1939)

Adolphe Gurnaud (1825 -1896)

Source: J-Ph. Schütz

??

Source: GG Sl. GradecSource: GG Sl. Gradec

• until WW II. the silvicultural systems in Slovenia were:– clear-cut system in the Alps– selection system the Dinaric region and in some private

forest (silver fir)– large scale uniform shelterwood for beech– coppicing

• in 1948 clear-cut system was prohibited and selection system was introduced to all forests -> partially unsatisfactory results, especially with beech

• in 50’ irregular shelterwood was introduced (CH)• in 60’ “free style” silvicultural system (Prof. Mlinšek)

Slovenia – Development of forestry

Geographical position of forest reserves () and old-growth forest (*) in Slovenia (Mlinšek et al. 1980)

2. Natural processes and CTN silviculture

Right: primeval forest Ravna gora (SI) in 2001: wind throw gap from 1983

Left: small-scale gap disturbance in primeval forest Rajhenav (SI) in 1998

Major disturbance pattern is endogenous small scale disturbance (< 1000 m2) with sporadic windthrow.Light remains sparse!!!

2. Natural processes and CTN silviculture

Velikost vrzeli (m2)

Šte

vilo

vrz

eli

0

4

8

12

16

20

24

28

0 100 200 300 400 500 600 700 800

Old-growth Trdinov vrh (SI) - 1999

Evidence of large scale wind disturbance

• records in old forest chronicles

• last decades:• Vivian, Wiebke in 1990 (120

m. m3)• Lothar in 1999 (180 m. m3)• Slovakia 2004 - 60 x 10 km

(2.5 m. m3)• only partly ecosystem

specific

2. Natural processes and CTN silviculture

Clear-cut management in Oregon (USA): erosion & site degradation, water management, wildlife, social functions

Clear-cut forest in the Olympic Peninsula, Washington. If you were driving, you’d probably not notice the clearing at all! And that, my friend, is the pictorial definition of a façade.

Landscape “make-up”

evenaged forest

State owned selection forests in the Dinaric region

3. How does CTN silviculture operate?

selection forest

The regeneration is introduced under slightly opened canopies

Irregular shelterwood system

The regeneration is introduced under slightly opened canopiesFormation and gradualFormation and gradual extension of gapsextension of gaps

Irregular shelterwood system

1960' - development of "free style" silvicultural systemby 1968 - the trilogy of Slovenian nature-based silvicultural systems was completed and published

Schematic presentation of the “free style” silvicultural system: (A) gradual conversion of spruce plantation to mixed uneven-aged forest, (B) transformation of large-scale regeneration to uneven-sized forest, (C) conversion of coppices (with standards) to regular forest

INITIAL CONDITION

AFTER 30 YEARS

AFTER 60 YEARS

Successful transformation of spruce plantation in Pohorje Successful transformation of spruce plantation in Pohorje

““Free style” system in silver fir – beech forestsFree style” system in silver fir – beech forests

Dauerwald – CC forest on a steep slope in Swiss Jura. Regular felling every 10 years.

Non-managed stand for the last 50 years, than heavier felling in 1999.

Sycamore maple of excellent quality in a CC forest. Tree as a goal and means of production. Felling age is defined individually.

Norway spruce of excellent quality in CC forest Lenzburg, CH.

Jurij Diaci

Close-to-nature forestry: linking ecological, economical and

social values

University of Ljubljana, Biotechnical FacultyDepartment for Forestry and Renewable Forest ResourcesSlovenia

1. Origins of close-to-nature forestry (CTN)2. Natural processes and CTN3. How does CTN silviculture operate?4. Economic aspects of CTN5. Social aspects of CTN6. Conclusions

• CTN forestry as slow food forestry or organic forestry (higher price?)

• certification (FSC)• ProSilva – CTN is economically very efficient!

• if you make calculations:– compare whole production cycle and more

– don’t use interest rates (if you use them you have to start from primeval forest)

4. Economic aspects of CTN

1) indirect influences on management success- take into account some ecological issues (sustained site

productivity; lower risks; future tax reductions for low ecological footprint and ecosystem services)

4. Economic aspects of CTN

1) indirect influences on management success- take into account some ecological issues (sustained site

productivity; lower risks; future tax reductions for low ecological footprint and ecosystem services)

2) direct influences on management success- less thinning and planting (use natural forces, tending by

continuous cover, eg. quality of beech, thinner branches, natural regeneration)

- mixture (grow valuable trees) auction; not every large diameter tree is valuable; but all high priced trees were large diameter trees; harvest them individually

- quality (apply thinning and pruning)

4. Economic aspects of CTN

• education is done mostly by retaining appropriate education is done mostly by retaining appropriate canopy cover (indirect tending)canopy cover (indirect tending)harvesting of adult trees is the most important harvesting of adult trees is the most important instrument of forest tendinginstrument of forest tending

• natural regeneration: knowledge on regeneration and natural regeneration: knowledge on regeneration and gap ecology => mixture, quality and quantity of gap ecology => mixture, quality and quantity of regenerationregeneration

CTN silviculture is about being lazy in a clever wayCTN silviculture is about being lazy in a clever way

1) indirect influences on management success- take into account some ecological issues (sustained site

productivity; lower risks; future tax reductions for low ecological footprint and ecosystem services)

2) direct influences on management success- less thinning and planting (use natural forces, tending by

continuous cover, eg. quality of beech, thinner branches, natural regeneration)

- mixture (grow valuable trees) auction; not every large diameter tree is valuable; but all high priced trees were large diameter trees; harvest them individually

- quality (apply thinning and pruning)

4. Economic aspects of CTN

Wood grows on wood; price 1805 EUR; Hessen (D).

1) indirect influences on management success- take into account some ecological issues (sustained site

productivity; lower risks; future tax reductions for low ecological footprint and ecosystem services)

2) direct influences on management success- less thinning and planting (use natural forces, tending by

continuous cover, eg. quality of beech, thinner branches, natural regeneration)

- mixture (grow valuable trees) auction; not every large diameter tree is valuable; but all high priced trees were large diameter trees; harvest them individually

- quality (apply thinning and pruning)FACIT: more profitable in CE conditions (less tending and risks,

individuality)

4. Economic aspects of CTN

LEGEND:crop treecompetitor

source: WSLsource: WSL

1) indirect influences on management success

2) direct influences on management success

FACIT: more profitable in CE conditions (lower costs, risks, individuality) – prof. Knoke

4. Economic aspects of CTN

Alternatives for urban and recreational forests:- non-intervention- conventional management- adapted CTN

5. Social aspects of CTN

Ljubljana urban forests in Mostec (results of non-interevntion)Ljubljana urban forests in Mostec (results of non-interevntion)

Czech national park Šumava

natural regeneration of pedunculate oak in large scale shelterwood

small clear cut in Norway spruce plantation

Conventional forest management

CTN CTN silviculture silviculture asas option near large urban areas in state or option near large urban areas in state or municipality owned urban forestsmunicipality owned urban forests

• origins of CTN: environmental crisis & existing CC practicesorigins of CTN: environmental crisis & existing CC practices• adapt CTN practices to natural conditions (disturbance)adapt CTN practices to natural conditions (disturbance)• CTN has small ecological footprint CTN has small ecological footprint • economic aspects: more profitable (less tending and risks, economic aspects: more profitable (less tending and risks,

individuality) + social effectsindividuality) + social effects• myth > new age movement or neo nature protection> myth > new age movement or neo nature protection>

alternativealternative > necessity = CTN > necessity = CTN

6. Conclusions