Management Goals and Treatments

A team of natural resource specialists from the Petawawa Research Forest and regional managers and scientists participated in a three-day workshop in July 2019 to develop the ASCC treatments for the site. Within the region, white pine forests are typically managed under the uniform shelterwood system that includes 1-3 partial harvests (preparatory, seed cut, first removal) designed to support regeneration establishment by providing a seed source and regulating light conditions. Once the white pine regeneration has surpassed a height of 6 meters (20 ft), the threat of weevil damage is minimized and the remaining overstory is harvested leaving a single-age stand to grow to maturity. The number of harvests will depend on the health, composition and basal area of the pre-harvest stand. For example, stands with lower pine components often have only the seed cut and a final removal.

The team developed a set of management objectives, desired future conditions, and silvicultural tactics for each of the ASCC Network adaptation options (Resistance, Resilience, and Transition). The ASCC project at the PRF will have 5 treatments: Control (business as usual), Resistance, Resilience, Transition, and un-treated reference conditions (no action). In each scenario, the existing forest is harvested and renewal activities initiated. 

NO ACTION (un-treated reference conditions) 

No Action - Un-treated reference conditions
Example of the "No Action," un-treated reference conditions at the PRF ASCC site; Photo Credit: Jeff Fera, Canadian Wood Fibre Centre

 

allow forests to respond to climate change without direct management intervention

Since climate change impacts all forests globally, we cannot maintain a true “control.” With this in mind, we consider an approach in which forests are allowed to respond to climate change in the absence of direct silvicultural intervention as an appropriate baseline for many questions.

“BUSINESS AS USUAL” CONTROL

*Standard strategies and approaches to achieve the Desired Future Condition (DFC) at the Petawawa Research Forest 

Under a no-change scenario, the BAU for white pine forests in the region
Under a no-change scenario, white pine forests will continue to be the dominate target species at the PRF; Photo Credit: Mike Hoepting, Canadian Wood Fibre Centre

Management Goals: 

Under a no-change scenario, the DFC at maturity (100 years) for white pine forests in the region is:

  • Species Composition: white pine dominated with other target species being red pine, red oak, and white spruce.  Minor species: trembling aspen, white birch, red maple, and balsam fir 
  • Structural Diversity: generally even-aged at maturity and two-aged during the uniform shelterwood renewal phase
  • Basal Area: total target of 40 m2/ha (174 ft 2/acre) at maturity; 50-75% white pine.
  • Growth and Productivity: basal area growth of 0.6 m2/ha/yr (2.6 ft 2/acre/yr)
  • Forest Pests: white pine blister rust and white pine weevil generally controlled through understory moisture and light conditions employed through the shelterwood system.
  • Wildlife Habitat: target of 25-wildlife trees/ha (10 trees/acre) for structure, mast, cavities and contribute to coarse woody debris.
  • Fire Adaptation: the uniform shelterwood system strives to mimic the light conditions and structure created by low intensity ground fires

Strategies & Approaches (mature stands, 30-40 m2/ha (320-430 ft2 /acre), 60-80% white and red pine): 

  • Two-cut shelterwood
    • Seed cut 12-14 m2/ha (129-151 ft2/acre) basal area
    • Final cut when height of white pine regeneration is 6 meters (20 ft) and contains 600 stems/ha (243 stems/acre) of desirable species
  • Mechanical and chemical site preparation for slash management, understory vegetation management, and seedbed creation
  • One year after site preparation, plant 1250 – 1500 seedlings/ha (500 – 600 seedlings/acre) of white pine from local seed zones  
  • Allow for natural regeneration of white pine, red pine, red oak, and spruce
  • Tending as needed until final cut to ensure species composition targets is achieved
  • Final rotation in 80-100 years

RESISTANCE

maintain relatively unchanged conditions over time

*Achieve the Desired Future Condition (DFC) with mild deviation from standard strategies & approaches at the Petawawa Research Forest 

Conditions at the PRF
Resistance at the PRF includes management to achieve the DFC with mild deviation from standard strategies & approaches; Photo Credit: Mike Hoepting, Canadian Wood Fibre Centre

Management Goals:

  • Regenerate a well-stocked, productive, pine-dominated stand (white pine and other drought-tolerant species common to the site) 
  • Maintain or increase production of high quality sawlogs and other forest products
  • Mange for wildlife habitat and mitigation of pests through partial harvesting and planned retention of the original overstory species
  • Increase resistance by incorporating planting stock from southern seed sources, increasing species diversity and reducing the rotation age

Strategies & Approaches: 

  • Two-cut shelterwood 
    • Seed cut, 12-14 m2/ha residual (129-151 ft2/acre) basal area 
    • Final cut when height of white pine regeneration is 6 meters, 600 stems/ha (243 stems/ acre) of desirable species
  • Mechanical and chemical site preparation for slash management, understory vegetation management, and seedbed creation; aides early regeneration survival and success
  • One year after site prep, plant 1500 seedlings/ha (600 seedlings/acre)
    • 33% white pine from local seed sources
    • 17% each of white pine from 3 southern seed sources (e.g. Simcoe, Essex, Ohio/Illinois)
    • 17% of red pine planted in open areas from local seed sources
  • Allow for natural regeneration of red oak, white pine, and white spruce.
  • Tending as needed in the first 40 years to ensure survival and growth of target species
  • Thinning (pre- and/or commercial) to accelerate sawlog production
  • Final rotation in 60-80 years; initiate uniform shelterwood system

RESILIENCE

allow some change in current conditions, but encourage eventual return to original conditions

*Achieve a similar Desired Future Condition (DFC) with moderate deviation from standard strategies & approaches at the Petawawa Research Forest 

Management Goals:

Managers and scientists discuss potential management treatments at the PRF
The resilience treatment at the PRF will aim to create a well-stocked, multi-aged structure with enhanced species diversity; Photo Credit: Jeff Fera, Canadian Wood Fibre Centre
  • Create a well-stocked, multi-aged structure (promote species composition of white pine > red oak > red pine > aspen > other species) 
  • Maintain/increase productivity and quality of wood products, and diversify wood products, including pine sawlogs  
  • Promote low susceptibility to disturbances, including drought, wildfire, wind, ice storms, insects and diseases
  • Enhance species diversity particularly among dominant species (including functional diversity, structural diversity, and genetic diversity)
  • Increase resilience to low intensity wildfires and reduce susceptibility to stand-replacing wildfires
  • Mange for wildlife habitat and mitigation of pests by utilizing expanding gaps to create a multi-aged stand with a gradient of light conditions.

Strategies & Approaches: 

  • Irregular shelterwood with expanding gaps
    • Gaps should be 1 to 2 tree heights in diameter (1/4 ha to 1/2 ha) (1/2 acre – 1 acre) with 20-25% of the area in gaps with feathered edges to promote white pine regeneration 
    • Gap expansion every 20-25 years
    • Subsequent plantings allow adjustment of species and seed zones to reflect changing climatic conditions
  • Site preparation in the gaps for slash management, understory vegetation management, and seedbed creation; aides early regeneration survival and success
  • Capitalize on the onsite species and natural regeneration (i.e., promote oaks on ridgetops, etc.)
  • One year after site preparation, plant local and southern seed sources in the gaps (1500 seedlings/ha (600 stems/acre)) and in the feathered edge areas (1250 seedlings/ha (500 stems/acre))
    • Gaps: 40% white pine from southern sources; 40% red oak from southern sources; 20% local red pine
    • Feathered Edges: 70% white pine from southern sources; 30% red oak from southern sources
  • Allow for natural regeneration of red oak, white pine, and white spruce
  • Tending as needed to ensure survival and growth of target species
  • Gaps to mature in 60-80 years; continue irregular shelterwood system

TRANSITION

Actively facilitate change to encourage adaptive responses

Management Goals:

  • Continue to provide quality wood products 
  • Maintain the potential for carbon sequestration in the short-term and increase potential over the long-term 
  • Promote a diverse species mix that is adapted to drought, wildfire, wind, ice storms, insects and diseases
  • Increase the genetic diversity of native species (including white pine and red oak)
  • Maintain wildlife habitat through structural retention and an increase in mast species

Strategies & Approaches: 

Seed Tree Treatment similar to the expected transition treatment at the PRF
The transition treatment at the PRF will include a clearcut with aggregate retention in variable sizes focused on existing white pine and red oak; Photo Credit: Mike Hoepting, Canadian Wood Fibre Centre
  • Clearcut with aggregate retention in variable sizes focused on existing white pine and red oak
    • Retention of 10-20% of the stand (treatment unit) 
  • Site preparation using mechanical, and possibly prescribed fire and chemical, treatments 
  • Plant pines and oaks with local and novel future-adapted species:
    • 20% red pine from local seed sources
    • 30% pitch pine from US seed sources
    • 30% red oak from southern seed sources (e.g. Essex, ON)
    • 20% white oak from southern seed sources (e.g. Essex, ON)
    • Up to 5% American chestnut for US seed sources (if available)
      • Other species to consider may be jack pine, bur oak, black cherry, hickory, virginia pine
  • Allow for natural regeneration of red oak, white pine, and white spruce
  • Tending as needed to ensure survival and growth of desired species
  • Species mix will be conducive to commercial thinning and irregular shelterwood management after 60-80 years