Overview of WSFG. Scott McPherson April 4, 2006 North Bay

Transcription

1 Overview of WSFG Scott McPherson April 4, 2006 North Bay

2 A Bit of History Methodology developed in 1994 In response to a new business relationship between Government and the forest industry In response to a new Act (CFSA) Every area harvested in Ontario must be regenerated to an acceptable standard Every regenerated area will be eligible for an independent audit of performance

3 Design Criteria A number of design features were identified: Compatibility Flexibility Procedure development coincided with 1996 FMPM development Consistent & verifiable results Efficient (one person crew) Transparent Best available science (updated in ) No standard that calls 40% a pass

4 The Product Intended for sites where the regeneration status is uncertain Provides information to support decisions about regeneration and silvicultural success Designed for single-cohort silvicultural systems (originally intended for clearcut and shelterwood, but new studies indicate we need to integrate overstorey analysis in procedure) Directly links to the SGR

5 Assessment Highlights Standards defined for each SGR All trees at least 30 cm tall are tallied by species and height class Healthy crop trees are assessed for wellspaced characteristics (blister rust don t tally it as FTG!) Well-spaced trees are assessed for freegrowing status A software package is available for summarizing data

6 Assessment Highlights A software package is available for entering and summarizing data User-guide is available

7 Assessment Highlights A software package is available for entering and summarizing data

8 The Procedure Provides: A description of the stand (well-spaced, effective and total density) at time of assessment A basis for forecasting future stand development A framework for developing local regeneration standards

9 The Procedure Should not be used to provide an FRI update!

10 The Procedure Interim (placeholder) FRI from WSFG should be based on: effective density (spp comp.), and site occupancy (proxy for FRI stocking)

11 The Procedure Generates: Total density (> 30 cm) and effective density by species (composition) Density by species by height class (structure) Number of well-spaced stems Number of well-spaced, free-growing stems (silvicultural and/or regeneration success) New an estimation of gaps or voids (percent empty plots PUP) Permanent gaps ( 16 m 2 ) expected to result in volume loss at time of harvest(s) Plotted on a map, these gaps give an overview of large voids in stand and site occupancy 100% - PUP = site occupancy (FRI update)

12 Data Products Assist in determination of regeneration status Provide information for relating current stand conditions to future development (e.g. with DMD) Help identify sites that may require additional silvicultural intervention Provide a basis for long-term, trend-throughtime analysis of silvicultural effectiveness

13 Specifics Timing of Assessment Dependant upon: Site productivity Height growth characteristics of the crop species Method of harvest Renewal prescription Maximum years specified to reach free-to-grow Recommended window 7-11 years after stand renewal Consideration for vegetation management

14 Definitions Well-Spaced Refers to the distance required between crop trees to ensure adequate future growing space Free-Growing Refers to the condition where a well-spaced tree can continue to survive and grow into the future in the presence of potentially competitive non-crop vegetation Not necessarily max growth or product value

15 Definitions Total and/or Effective Density Total density refers to the number of stems tallied across all height classes Effective density refers to those stems which have a high probability of remaining in a dominant or co-dominant canopy position

16 Step 1 Stratify the area Ecological, site and terrain conditions Silvicultural history Observed variation in the crop trees Type, abundance and distribution of residuals and/or competing vegetation Avoid excessive splitting or lumping

17 Step 2 Determine the sample size A minimum of 31 plots is required to satisfy the underlying statistical assumptions - this number of plots is established in strata less than 10 ha Minimum sample size for strata 10 ha is calculated as half the stratum area plus 31 i.e., a 20 ha stratum would require: (20 2) + 31 = 41 plots Maximum sample size is capped at 31 + stratum area

18 Step 3 Establish sample grid and survey lines All parts of the stratum must have equal opportunity to be sampled Plots are arranged within a grid to ensure the stratum is fully surveyed, mapping is facilitated, and any stand variability is adequately described (spatial patterns) Lines must be perpendicular to any underlying pattern (e.g., site prep corridors)

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20 Step 4 Complete project information header sheet Crop species Target forest unit Height standards Density standards WSFG standards You need to know this info while at your plot

21 Step 5 Establish circular plots (16 m 2, radius 2.26 m) Plots that fall on exposed bedrock or conditions resulting from forestry activities are included

22 Step 6 Tally all trees (> 30 cm tall) by species into height classes Recommend that the upper limit of the first height class correspond to the minimum height criteria for crop species Second and third height classes established to aid in forecasting stand development and identifying structure Additional height classes can be added

23 Step 7 Apply the well-spaced criteria to crop trees A maximum of four well spaced trees can be tallied for each plot Attention must be paid to tree health and vigour Only trees within the plot can be tallied Single vs. double sweep

24 Well-Spaced Rules If the crop tree has no other crop tree closer than 1.8 m, it may be counted If a neighbouring crop tree is between 1.2 and 1.8 m, require two quadrants free If a neighbouring crop tree is 1.2 m away, can only count one tree All distances pith to pith

25 Step 8 Apply free-growing criteria Recognition given to the type and level of competition (trees and tall shrubs), but may need to add local flavour if other competitors are a concern (fireweed, Calamagrostis, bracken) Competition assessed within a 1.2 m radius Heights rounded to the nearest 10 cm

26 Competition Trees cannot be overtopped Fig cm Fig. 12 More than 1.5 times the height of brush (tall shrub species)

27 Competition Fig quadrants can have brush > 67% of crop tree height Rubus rule Fig. 14 (may need to be adjusted to local conditions e.g. blackberry in Parry Sound)

28 Competition Free-growing trees are 2 times the height of hardwood tree competition Fig. 15

29 Competition Fig. 16 Crop trees less than twice the height of the tree competition can be free-growing if the competition is confined to only one quadrant surrounding the tree.

30 Competition Crop trees with faster / similar height growth rates than tree competitors are FTG if the competing stems are the height of the wellspaced tree and occur in a max of two quadrants. Fig. 17

31 Free-growing criteria

32 Step 9 Determine the regeneration status Conduct supplemental sampling if necessary

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34 Step 10 Post-survey assessment and evaluation Determine the need for further treatments, e.g. release, PCT Determine regeneration status Assign interim stand description (FRI placeholder)

35 May the Forest be with you