Intro to Silviculture and Forestry Practices

ENVS 31

How have things changed at Dartmouth’s second college grant? Why?

Global warming has diminished the amount of time that the ground is frozen by 4-8 weeks each year. This lengthens the spring mud conditions that machinery cannot operate in without getting stuck. This has overall decreased the cords of wood produced per year from 8,000 to 4,000.

Why is logging at the second grant primarily done in the winter?

To avoid muddy conditions that inhibit harvest and because impact on soil is diminished when the ground is frozen.

How is ecology “applied”?

In the form of management. Often forestry/silviculture.

Traditional forestry often focused on…

timber production by clearcutting

Conservation and management of forested areas is guided by management _____ and __________.

Goals, objectives.

Goals

Statements of desired outcomes or future conditions of a forest.

• Broadly worded to establish overarching aims for a given area.

• Generally apply to the entire forest area (non-site specific).

Objectives

Time-specific management statements of planned results outcomes corresponding to established goals.

• Generally achieved by implementing projectiles or activities in specific areas of a forest.

• Have measurable outcomes.

What is silviculture defined as?

The science of understanding and managing forests, includes the nuances of place-based approaches, but it is also seen as an art.

On what basis should silviculture be conducted?

The basis of developing ecological knowledge and principles.

What ecological processes are relevant to silviculture and forestry practices? What do they have in common?

They typically occur over long intervals (decades, centuries, millennia).

• Disturbance regimes

• Biodiversity

• Forest development

• Productivity

What is adaptive management?

A strategy that should be conducted in silviculture. Involves returning to a site every 3-5 years to see if plans are achieving the desired results. If not, then the plans should be adjusted accordingly.

What are the three steps of adaptive management?

Test assumptions —> documentation —> adaptation

Why is adaptive management especially important in the field of silviculture?

Silviculture and forestry in general are relatively new sciences, and this means our understanding will inevitably change over time. This makes adapting with the current science necessary for high-quality management over time.

On what scales should we think about silvicultural management strategies?

• Individual tree level

• stand level

• watershed/landscape level

• biome/regional level

What factors can be considered on the tree level?

Mycorrhizal association, recruitment, tree growth.

What factors can be considered on the stand level?

Mean species diversity, productivity, composition, size distribution, mortality, competition.

What factors can be considered on the watershed/landscape level?

Vegetation patchiness, forest development, total species diversity.

What factors can be considered on the biome/regional level?

Habitat differentiation, species extinction.

Stands are _________, and they have ________ properties.

Ecosystems, emergent properties.

What are the emergent properties of stands?

Structure, species composition, growth rates, volume/carbon, habitats, aesthetics.

How can we think about Emergent Properties of stands, and what information is needed for silviculture.

Properties that are the “end goal of the forest,” but require understanding and consideration of the many parts and interactions within the stand.

What are the two primary objectives of silviculture?

To provide a perpetual supply of tangible goods and intangible benefits and services. Promoting accessibility and access to these resources, and maintaining these resources and the conditions that are conducive to them.

What are the tangible goods provided by silviculture?

Logs, pulpwood, bioenergy, non-timber forest products, wildlife, forage.

What are the intangible benefits and services provided by silviculture?

Protection of ecosystem structure and function, recreation, aesthetics, scenery. 

Other goals of silviculture:

• Maintenance of a particular set of ecological conditions

• Promote forest resilience to damaging agents (insects, diseases, fire, wind). 

• Restocking of stands following natural and anthropogenic disturbance. 

• Execution of policies (constraints of laws and regulations) regarding forest practices.

  
  

What are the roles of silviculture in forest?

• Imitating Nature through Silviculture

• Conservation of Site Productivity

• Control of Stand Structure and Process

• Control of Forest Composition

• Control of Stand Density

What can processes does silviculture seek to imitate?

Disturbance regimes, ecological processes, structure, composition, and function.

What types of site productivity does silviculture seek to conserve?

• Control of microclimate, soil protection (e.g. reduce erosion risk). 

  • If all the trees are knocked over on a hillside, you can plant trees to keep soil in place. 

  • Leaving lines of trees along roads to block public view of clearcuts is also a management strategy of (economic/anthropogenic) productivity in an area to not get public pushback.

What does it mean for silviculture to control stand structure and process?

• Species and age classes, vegetation cover, distribution of diameter classes. 

What does it mean for silviculture to control forest composition?

Desirable species, control of disturbance and regeneration processes.

What does it mean for silviculture to control stand density?

Control of spatial properties, growth management, thinning, forest health.

Silviculture varies in practice across _________ and ____.

Intensity and scale

What is the value of silviculture, in essence, what does it provide?

Silviculture provides a complete approach to regenerating, tending, harvesting, that meet short- and long-term objectives. Planned program of treatments over the entire life of a stand.

What are the three phases where silviculture can implement treatments?

Regeneration treatments → tending treatments → harvest 

What are regeneration treatments?

Done during the reproduction or regeneration period, type and origin of regeneration.

What are tending operations?

Done to improve the existing stand, regulate growth, or manage structure.

What are the two common types of tending operations?

1. Thinning (adjust stand density and/or composition)

2. Release (improve young stands).