Culturally-Important Ecosystem Services: Long-term Losses in Coastal British Columbia Watersheds

Transcription

1 Culturally-Important Ecosystem Services: Long-term Losses in Coastal British Columbia Watersheds Sarah Gergel, Jessica Morgan, Collin Ankerson Centre for Applied Conservation Research University of British Columbia Vancouver, BC Canada FORESTRY

2 Ecosystem Services: Why Mapping? Why Long-term? Where have ES been lost? How much has been lost? Human Footprint on Earth Where might ES be restored? Karieva et al. 2007

3 Trade-offs Among Ecosystem Services Foley et al. 2005

4 Mapping ES Bundles (or Concordance) 5 Ecosystem Services in South Africa Surface water supply Water flow regulation Soil accumulation Soil retention Carbon storage Egoh et al. 2008

5 Clayoquot Sound British Columbia, Canada

6 QUESTIONS Historically Did cultural ecosystem services overlap with ecological and economic services? What were underlying drivers of ES abundance and losses?

7 Limitations in Mapping Ecosystem Services Based on generalized land cover Coarse-grained spatial data (e.g., Landsat) Limited historical timeframe

8 Western Red Cedar (Thuja plicata) Tree of Life Vital role in cultures of aboriginal peoples on the west coast Cedar materials were used for shelter, clothing, tools, and transportation Produces its own fungicide: thujaplicin Timber very suitable for exposed building materials (shingles, shakes, exterior siding) Fine, straight grained, easily split wood

9 Western Red Cedar Different Services Derived from Different Species

10 Some services depend on size, age, decay of trees Services from Large/Old/Dead Trees: Western Red Cedar

11 Snags Coarse Woody Debris (CWD)

12 New Approach for Long-term Mapping of Ecosystem Services 1930 s Air Photos Historic aerial photos: oldest spatial record pre-dates most logging intact landscape condition 40 yrs before Landsat high spatial resolution links to timber inventory species-specific info 1:15,000 Morgan et al Bioscience

13 Overview of Approach Air Photo Interpretation of Forest Attributes Derivation of Ecosystem Services (with ecological, cultural, economic values) Comparison of Services in Space: Overlap among services Landscape-level drivers of services

14 Photo-Interpretation of Forest Stand Attributes Western Red Cedar Manual Delineation and Interpretation of Polygons 1 st /2 nd Leading Spp. Crown Closure Height Age Productivity class 1937 / 38 air photos 1:15,000 scale 8 Sites (~1250 ha each) photo-interpreted pairs

15 Historic Ecosystem Services Ecological Structure for Wildlife (Snags, CWD) Cultural Large/Tall Cedar Economic Timber Volume

16 Culturally Important Areas Tall Cedar (>35m)

17 Merchantable Timber Volume (>32.5 cm dbh) Based on Aerial Photo Interpretation of Relative Abundance, Age and Productivity of 1 st and 2 nd Leading Species Estimated Using Known (well-calibrated) Relationships Between Sizes (Height/Diameter/Taper) for Different Species TIPSY Program (BC Ministry of Forests & Range) Routinely used - and understood - by BC forest managers m 3 /ha ,200 1,200 1,786

18 TIPSY Estimates for Density of Snags (# ha -1 ) Coarse Woody Debris (m 3 ha -1 ) Empirically-derived based on: Species - specific mortality and decay rates

19 QUESTIONS Historically, did ecological, cultural and economic ecosystem services overlap spatially?

20 Historic Services in Culturally Important Areas Snags Timber Coarse Woody Debris Snags / ha Leading Species cm3 / ha A A B 500 C 10 A B 0 0 Leading 2nd Species None None Species A B C Leading Species 2nd Species cm3 / ha nd Species None Tall Cedar (>35m)

21 QUESTIONS What are the underlying drivers of historic ES and their losses? 1937/

22 Historic Ecosystem Services Vary with Landscape Position (log) Total Snags ha Snags Bottom Mid-Slope Top (log) Volume cm -3 ha CWD Bottom Mid-Slope Top (log) Volume cm 3 ha Timber Volume Bottom Mid-Slope Top

23 Productivity Varies with Landscape Position Mountain Top Mid-slope Frequency Valley Bottom Productivity Site Index (Tree height at 50 years age)

24 Harvest Concentrated on Most Productive Sites Percentage of Each Polygon Harvested (Mean) Mountain Top 22% Harvested Mid-slope 26% Valley Bottom 42%

25 Historical Losses Across the Landscape 37% of Landscape Harvested Areas with Tall Cedar Loss 56% Coarse Woody Debris (Volume) Loss 45% Number of Large Snags Loss 56%

26 Summary Culturally important areas overlapped with high values of several other services Productivity and landscape position are important underlying drivers of: - abundance of services - loss of services

27 Significance Long-term reconstructions are rare Snapshot of today can be misleading Landscape position rarely accounted for, yet may drive location, abundance, and losses High resolution, species-specific information needed (for ecological, cultural and economic values) New methods are sorely needed for quantifying cultural services

28 FUTURE WORK Visual quality Jobs Riparian services Carbon storage

29 Acknowledgments Aerial Photography: NSERC Discovery Grant Program BC Forest Science Program BC Ministry of Forests & Range 1937/ Thanks for valuable input from: Kathryn Kirby (UBC) Anne-Helene Mathey (UBC) Rob Kozak (UBC) Andy MacKinnon (MoFR and UBC) Roy Kregosky (Global Geomatics, Ltd.)