Incorporating multi-cohort old aspen and mixedwood dynamics into a long term forest management plan

Transcription

1 Incorporating multi-cohort old aspen and mixedwood dynamics into a long term forest management plan Session 4a Beyond Breakup Boreal Mixedwoods 2012 Conference Edmonton, AB Paul LeBlanc June 19 th, 2012

2 Outline Year Plan macro overview 2. Ecological Landbase 3. Ecological Yield Curves 3.1 more than just timber 3.2 Successional Trends 4. Old aspen and mixedwood multi-cohort dynamics vs. single-cohort breakup 5. Future Forest Conditions 6. Conclusions

3 1. 20 Year Plan macro overview LANDBASE YIELD CURVES MANAGEMENT GOALS MODELING -Spatial Harvest Schedule -Indicator Outputs -ecological -social -economic iterative process called Scenario Planning

4 2. Ecological Landbase LANDBASE YIELD CURVES MANAGEMENT GOALS MODELING -Spatial Harvest Schedule -Indicator Outputs -ecological -social -economic iterative process called Scenario Planning

5 2. Ecological Landbase Duck Mountain Provincial Forest AGES older forest, dominated by 1890 s massive fire majority of forest yrs old (based on ground & photo inventory ages) however, the forest is older than we think Dr. Jacques Tardif fire history

6 2. Ecological Landbase Duck Mountain Provincial Forest Species Groups ring of aspen around forest s perimeter aspen sites greatest area (ha), followed by conifers, then aspen-spruce mixedwood, and spruce-aspen mixedwood

7 An ecosite classification system and ecosite mapping system was developed (Arnup et al. 2006) AB & SK (ecosite level) ON & MB (V-type & S-type) eco element level

8 Ecosites combination of soils, tree canopies, and understory vegetation

9 Softwood % ecosites were aggregated into ecological strata - used in 20 Year Plan Soil Moisture/Texture Dry/Coarse Fresh/Fine Moist/Fine Wet/Organic SWD1 SWD2 SWD3 SWD4 S softwood (80-100% swd) MWD1_M MWD2_M MWD3_M M softwood-dominated mixedwoods MWD1_N MWD2_N MWD3_N N hardwood-dominated mixedwoods (50-80% swd) (20-50% swd) HWD1 HWD2 HWD3 H hardwood succession or management can increase, decrease, or maintain softwood % (up or down on above table) (0-20% swd) cannot change the soil type (can t move left or right on above table)

10 3. Ecological Yield Curves LANDBASE MANAGEMENT GOALS Ecological YIELD CURVES MODELING -Spatial Harvest Schedule -Indicator Outputs -ecological -social -economic iterative process called Scenario Planning

11 Snags or CWD per ha 3.1 more than just timber Snags and Coarse Woody Debris (CWD) strata=hwd2 Hwd Snags/ha Swd Snags/ha Hwd CWD/ha Swd CWD/ha Age (years) spruce germinating on CWD

12 Carbon (MgC/ha) 3.1 more than just timber HWD2 carbon curve Stem-BIOMASS Non-Stem Biomass BIOMASS TOTAL SOIL TOTAL GRAND TOTAL C Stand Age (years)

13 3.2 Successional Trends 1,500 Permanent Sample Plots were established in Riding Mountain, Manitoba in 1946 by the Dominion Forest Service in stands aged 120 to 150 years old. Remeasurements occurred in 1951, 1956, 1961, 1966 and 1969, and were further supplemented by 284 PSP measurements (LP Canada in 2002) 50 years of remeasurement data!!! (from stands now aged years old)

14

15 VOLUME (M 3 /HA) > 80% ASPEN MODEL PSP remeasurement data TOTAL HARDWOOD SOFTWOOD AGE

16 Even-aged aspen ~ 80 yrs old -one canopy; one age; narrow dbh range; some snags & coarse woody debris (~ 200 m 3 /ha)

17 Even-aged aspen ~ 80 yrs old -one canopy; one age; narrow dbh range; some snags & coarse woody debris (~ 200 m 3 /ha)

18 Uneven-aged aspen 160 yrs old -2+ canopies; multiple ages; wide dbh range; lots of snags & coarse woody debris (~ 120 m 3 /ha)

19 VOLUME (M 3 /HA) MIXEDWOOD MODEL PSP remeasurement data TOTAL 200 SOFTWOOD HARDWOOD AGE (YEARS)

20 4. Old aspen and mixedwood multi-cohort dynamics vs. single-cohort with breakup started with single-cohort yield curves later, we incorporated multi-cohort dynamics into the yield curves

21 Merchantable Volume (m3/ha) aspen-white spruce mixedwood strata (NWS) 300 NWS (closed) strata (16% of FMU 13 landbase) ACTUAL DATA RANGE Spruce Aspen TOTAL VOL Age (years)

22 Merchantable Volume (m3/ha) add death age at 160 years death age Age (years)

23 the 160 yr old death age stand would have all the wood on the ground - and look like the Mt. St. Helens eruption

24 death age, regen, growth over several cycles -ages 120+ are assumed (no data), including death age where stands are assumed to crash to zero, then regenerate 2 nd rotation

25 Merchantable Volume (m3/ha) ecological yield curve (with PSP data up to 200 yrs) aspen-spruce mixedwood (NWS closed) strata (16% of FMU 13 landbase) -incorporating 2nd cohort (gap-phase regeneration) Successional Trends Softw ood Hardw ood TOTAL Vol Softw ood Assumed Succn Hardw ood Assumed Succn Total Volume Assumed Succn Age (years) DOESN T CRASH TO ZERO! -big difference in habitat values, since there is forest canopy still present

26 Single & multi-cohort overlay -PSP remeasurement data up to 200 yrs (solid green line) using multi-cohort -ages 200+ (green dashed line) assume gap-phase regeneration continues

27 What is the significance? -creates a 60 year gap (striped area) until stand is eligible for harvest - reseting stand to age to zero means there can never be stands aged 160 yrs+ -negatively affects biodiversity, wildlife habitat

28 5. Future Forest Conditions - Growing stock (m3) total single-cohort with death age multi-cohort

29 5. Future Forest Conditions - Unharvested Volume Loss (mortality) single-cohort with death age multi-cohort

30 5. Future Forest Conditions - Age Class Distribution single-cohort with death age multi-cohort

31 Interspersion Old Less old forest High Low Young Biodiversity space Conifer Cover Type Deciduous Less Interspersion Reduced Biodiversity space Less hardwood

32 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC)

33 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC) allowed old stands to get older than 160 yrs especially important for old stands at the beginning of a 200 yr modeling run

34 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC) allowed old stands to get older than 160 yrs especially important for old stands at the beginning of a 200 yr modeling run captured real-life transition of even-aged stands to uneven-aged stands (vs. stand breakup )

35 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC) allowed old stands to get older than 160 yrs especially important for old stands at the beginning of a 200 yr modeling run captured real-life transition of even-aged stands to uneven-aged stands (vs. stand breakup ) also captured the additional biodiversity from these uneven-aged stands (lots of snags, CWD, tree canopies)

36 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC) allowed old stands to get older especially important for old stands at the beginning of a 200 yr modeling run captured real-life transition of even-aged stands to uneven-aged stands (vs. stand breakup ) also captured the additional biodiversity from these uneven-aged stands (lots of snags, CWD, tree canopies) more even future wood flows

37 6. Conclusions -incorporating multi-cohort dynamics had a very profound effect on the Future Forest Condition (FFC) allowed old stands to get older especially important for old stands at the beginning of a 200 yr modeling run captured real-life transition of even-aged stands to uneven-aged stands (vs. stand breakup ) also captured the additional biodiversity from these uneven-aged stands (lots of snags, CWD, tree canopies) more even future wood flows