Living forest laboratories for sustainable silviculture in British Columbia

Transcription

1 Living forest laboratories for sustainable silviculture in British Columbia A.K. Mitchell Natural Resources Canada Canadian Forest Service Pacific Forestry Centre Victoria, BC. A. Vyse British Columbia Forest Service Research Forester Emeritus Southern Interior Region Kamloops BC. MASS old-growth Presented for Society of American Foresters AGM, Silviculture Symposium, Fort Worth Texas, October 21, 2005.

2 SCIENCE-BASED FOREST MANAGEMENT THE SOCIAL CONTEXT FOREST OWNERSHIP - 95 % public FOREST LEGISLATION - Results-based Forest Practices Code (1994) - Forest and Range Protection Act (2004) ALTERNATIVES TO CLEARCUTTING - Partial cutting and retention systems TIMBER SUPPLY - Fall down in growth and yield ENVIRONMENTAL VALUES - Maintaining ecosystem attributes

3 WHY SCIENCE-BASED FOREST MANAGEMENT? INTERNATIONAL THIRD PARTY FOREST CERTIFICATION NATIONAL CRITERIA AND INDICATORS OF SUSTAINABLE FORESTRY PROVINCIAL THE RESULTS-BASED FOREST PRACTICES CODE REGIONAL MANAGING FOR MULTIPLE VALUES

4 MANAGING FOR MULTIPLE VALUES THE SUSTAINABILITY CHAIN DIVERSIFICATION OF FOREST STRUCTURE PARTIAL CUTTING and RETENTION SILVICULTURE SYSTEMS HABITAT BIODIVERSITY ECOSYSTEM PROCESSES SUSTAINABILITY Source: Burgess et al. 2001

5 MANAGING FOR MULTIPLE VALUES KEEPING FOREST STRUCTURE What is forest structure? Retained attributes of the forest that are representative of the pre-harvest stand condition. These include: Fallen trees Coarse woody debris Standing dead trees Multi-species Multi-storied Multi-aged Diverse life-forms forms

6 CONVENTIONAL AND RETENTION SILVICULTURE SYSTEMS THE TOOLBOX 100% Clearcut Seed Tree & Shelterwood Systems 0% Source: Burgess et al Retention Systems Removal Retention 10% 70% Retention Level Selection Systems

7 DEFINING RETENTION SILVICULTURE SYSTEMS Regeneration is an important but not dominating objective. Silviculture practices incorporate biological diversity objectives and visual concerns. (Clayoquot Sound Scientific Panel, 1995)

8 CHOOSING SILVICULTURAL ALTERNATIVES GROUP OR SINGLE TREE RETENTION? SMALL OR LARGE OPENINGS?

9 MONTANE ALTERNATIVE SILVICULTURAL SYSTEMS (MASS) SICAMOUS CREEK RESEARCH PROJECT

10 MONTANE ALTERNATIVE SILVICULTURE SYSTEMS Aggregated and dispersed retention in a coastal montane forest: operational, economic and ecological effects Campbell River MASS 700 B26 Vancouver Island SW1 PC CC CC2 CC3 OG GT1 SW2 800 PC2 GT2 GT3 PC3 SW3 E-1950 H4 M A S S Montane Alternative Silvicultural Systems 0.5 km 0 1 km Treatment CC Clearcut GT Green Tree Retention SW Shelterwood PC Patch Cut (retention shaded) OG Old Growth

11 MONTANE ALTERNATIVE SILVICULTURE SYSTEMS Retention level increasing 5 % 25 % 50 % 0 % Patch Cut (PC) Shelterwood (SW) Green Tree (GT) Clearcut (CC)

12 SICAMOUS CREEK RESEARCH PROJECT Partial cutting in a subalpine forest: opening size effects on regeneration, nutrient cycling and biodiversity. 10ha ITS 0.1 ha 1 ha

13 SICAMOUS CREEK RESEARCH PROJECT Retention Retention level level decreasing decreasing 80 % 60 % 10.0 ha (CC) 80 % 1.0 ha (PC) Gap Gap size size increasing increasing 0.1 ha (GS) ITS

14 VALUES AND INDICATORS Value: Regeneration Indicators: Natural, planted, recruitment, growth. Value: Nutrient cycling Indicators: Decomposition, nutrient forms and abundance. Value: Biodiversity Indicators: Plants, small mammals, arthropods, birds.

15 REGENERATION Aggregated and dispersed retention Indicator CC PC GT SW Recommendation Seedfall (seeds/square m) SW Natural regeneration (% survival year 3) CC Natural regeneration height (cm at year 5) CC, PC, GT Planted seedling survival (% over 5 years) CC, PC, GT Planted seedling height (cm at 7 years) CC, PC, GT Source: Beese et al Choices change depending on the indicator

16 NUTRIENT CYCLING Opening size Indicator 10 ha 1 ha 0.1 ha ITS Recommendation Mineral nitrogen (µg N/g soil) , 1.0, 0.1 Decomposition needles (% loss/5 years) ITS Litterfall (kg/ha/year) ITS Source: Huggard and Vyse 2000b

17 BIODIVERSITY Aggregated and dispersed retention Indicator CC PC GT SW Recommendation Richness (number of species) ns ns ns >> SW (PC **) Abundance (frequency of species) ns ns ns >> SW (PC) Species losses (% pre-harvest at year 5) SW (PC) Bryophyte cover (% cover year 5) SW (PC) ** when PC retained aggregates are included Source: Beese 2000

18 FOREST INFLUENCE How big an opening is needed to be free of the influence of the forest??? How big a clump is needed to have characteristics of the forest interior?

19 FOREST INFLUENCE Do edge effects extend to cover 50% of the cut area? EDGE EDGE 100 Forest Clearcut Forest Percent of maximum value Wind speed Forest floor moisture Diffuse light N (W) edge S (E) edge Distance from edge (m) Source: Huggard and Vyse 2000a

20 EDGE EFFECTS BIODIVERSITY INDICATORS Cover (%) Forest Clearcut Forest Herbs Shrubs Bryophytes Increasers Veratrum N edge S edge Distance from edge (m) Source: Huggard and Vyse 2000a The influence of the forest on the opening can be very narrow.

21 EDGE EFFECTS NUTRIENT CYCLING INDICATORS 100 Forest Clearcut Forest Percent of maximum value NO 3 Potassium N edge S edge Distance from edge (m) Source: Huggard and Vyse 2000a Some indicators increase while others decrease.

22 TOWARD SCIENCE-BASED FOREST MANAGEMENT VISUAL QUALITY INDICATORS

23 TOWARD SCIENCE-BASED FOREST MANAGEMENT Science may be able to tell you what is correct but it can not tell you what is right. (Anonymous) Viewer s s Choice D+A? A?

24 SCIENCE FOR INFORMED FOREST MANAGEMENT Evidence for the link between forest structure and healthy ecosystem processes. Interrelationships between forest structures, habitat conditions and biodiversity. Comparisons among silvicultural systems.

25 Long term FINDING short term FUNDING THE LIVING FOREST LABORATORIES INITIATIVE Understanding when forestry practices and other human activities may change ecosystems beyond natural limits, threatening the integrity and resilience of our forests.

26 Applied Forest Ecological Experiments in BC Source: Vyse et al Hypothesis testing for science-based management

27 How will this contribute to science based management? The most important uncertainty hindering decision making was the inability to provide adequate scientific information to answer a number of important policy questions related to ecosystem services and human well-being. Source: The Millennium Ecosystem Assessment Report

28 Where are we going from here? The Living Forest Information Network Forests for People Developing a strategy to use long-term large-scale silvicultural research installations as living forest laboratories.