Field Studies: Forestry Notes

Forestry Overview

Definition: Forestry is the science, art, and practice of managing, conserving, and using forests, woodlands, and associated resources for ecological, economic, and social benefits.

Components of Forestry

Tree cultivation
Forest restoration
Harvesting
Wildlife habitat protection
Land management

Tree Types and Primary Economic Uses

Teak: High-value timber
Mahogany: Luxury furniture
Pine: Construction & paper
Eucalyptus: Paper & biomass
Apple: Fruit production
Coconut: Oil, fiber, and water
Walnut: Nut & fine wood
Almond: Nut production
Olive: Olive oil & fruit
Rubber Tree: Natural rubber
Frankincense: Resin for incense
Willow: Biomass & biofuel
Neem: Medicinal & pesticides
Sandalwood: Essential oils & incense
Cinnamon: Spices & oils

Ecological Importance of Forests

Carbon sequestration: Absorption of $CO_2$ from the atmosphere.
Biodiversity conservation: Habitat for 80% of terrestrial species.
Water cycle regulation: Prevents soil erosion and aids in water filtration.
Soil enhancement.
Climate regulation: Provides shade and reduces heat via evapotranspiration.

Economic Importance of Forests

Source of raw materials, employment, and trade.
Timber and wood products.
Non-timber forest products (NTFP): Fruits, nuts, medicinal plants, etc.
Bioenergy and carbon markets: Biofuel and carbon offset markets.
Employment: Logging, sawmilling, conservation, and research.
Tourism and recreation.

Social Importance of Forests

Livelihoods for rural communities: Source of food, fuel, and building material.
Cultural and spiritual value.
Public health.
Disaster risk reduction.

Conservation vs. Preservation

Conservation: Sustainable use and management of forest resources to balance ecological health with human needs.
- Focuses on responsible harvesting, restoration, and long-term sustainability.
Preservation: Strict protection of forests to maintain their natural state, prohibiting most forms of human use and exploitation.
- Prioritizes ecosystem integrity over economic benefits.

Key Principles of Conservation

Sustainable resource use: Allows controlled logging, hunting, and extraction of non-timber forest products while ensuring forest regeneration.
Ecosystem management: Focuses on maintaining biodiversity, water quality, and soil health while permitting economic activities.
Multiple-use policy: Forests are used for timber, recreation, wildlife habitat, and other economic benefits.
Active human intervention: Encourages reforestation, selective logging, controlled burns, and pest management.

Conservation Examples in Forestry

Sustainable logging practices: Selective cutting instead of clear-cutting to minimize ecosystem damage.
Agroforestry systems: Integrating tree planting with agriculture to maintain land productivity.
Forest certification programs: Organizations like the Forest Stewardship Council (FSC) ensure responsible timber harvesting.
National Forests: Managed for a combination of resource use and environmental protection.
Conservation advantages: Supports economic growth while maintaining forest health, encourages responsible resource use, and promotes long-term ecological sustainability.
Conservation risks: Potential for overexploitation without proper regulation, requiring ongoing monitoring and enforcement.

Gifford Pinchot

Founded the Forest Service in 1905.
Wealthy, with interests in forestry and politics.
Quote: "The greatest good for the greatest number for the longest time."
Today's Forest Service mission: To sustain the health, diversity, and productivity of the nation's forests and grasslands to meet the needs of present and future generations.

Key Principles of Preservation

Non-use focus: Limits or bans activities like logging, hunting, and mining.
Biodiversity protection: Maintains untouched habitats for endangered species and ecological functions.
Minimal human impact: Encourages passive management where nature is left to regenerate on its own.
Wilderness designation: Emphasizes the value of forests for their intrinsic and aesthetic worth.

Preservation Examples in Forestry

National Parks and Wildlife Reserves: Strict rules to protect biodiversity.
Old-growth forest protection: Banning logging in historic forests to preserve biodiversity.
Strict conservation laws: Legal frameworks prevent deforestation in key ecological areas.
- Preservation advantages: Ensures long-term ecosystem stability, protects endangered species and biodiversity, and helps prevent resource depletion and habitat destruction.
- Preservation disadvantages: Can limit economic opportunities from forest resources, create conflict with local communities who may rely on forests for livelihoods, and requires significant government funding and enforcement.

John Muir

His work led to the establishment of the US Park Service in 1916.
Emigrated from Scotland, attended the University of Wisconsin-Madison, worked in a factory, and had an awakening after an injury.
Quote: "Make their lives wretched until they do what is right by the woods," urging citizens to advocate for Yosemite.
Co-founded the Sierra Club.
Advocated for little to no industrial profit from forests.
He and Pinchot helped protect open spaces, with National Parks often surrounded by National Forests.

Career Opportunities in Forestry

Government agencies: US Forest Service, Bureau of Land Management, National Forest Service, State Agencies.
- Roles include forest conservation and protection, sustainable resource management, policy development and enforcement, public lands and recreation management, research, education, community engagement, climate change mitigation, and carbon sequestration.
Private sector: Timber companies, consulting firms.
- Roles include timber and wood product production, forest land ownership and management, reforestation and sustainable forestry, bioenergy and renewable resources, non-timber forest products (NTFPs), urban and landscape forestry, forest conservation and ecotourism, research, innovation, and technology.
Non-profits and research: Conservation organizations, academia.
- Roles include forest conservation and restoration, advocacy and policy influence, community-based forestry and indigenous rights, public education and engagement, wildlife and biodiversity protection.

Forest Restoration Techniques

Assisted natural regeneration
- Protecting and nurturing naturally occurring seedlings and sprouts to accelerate forest recovery
- Remove competing vegetation, protecting young trees from grazing, enhancing soil conditions
- Cost-effective and works well in areas where natural seed sources are present
Controlled burns (prescribed burning)
- Intentionally set, carefully managed fires
- Reduce excess vegetation, recycle nutrients, promote growth of fire-adapted plant species
- Helps prevent severe wildfires, maintain healthy ecosystems, support species that depend on fire for regeneration
Invasive species management
- Controlling or eradicating non-native plants, animals, or pathogens that threaten native ecosystems
- Mechanical removal, herbicides or pesticides, introducing natural predators or competitors (biological control), and habitat restoration

Other Happenings in Forestry

Agroforestry

A sustainable land use system that integrates trees, crops, [and] livestock in a way that maximizes environmental, social, and economic benefits
Incorporates woody perennials into agricultural landscapes
Shade and wind protection provided by trees can moderate temperature and conserve moisture
Habitat provided by trees can promote pest-controlling biodiversity
Diversified income for farmers
But, trees take a long time to mature and require specialized, species-specific knowledge

Reforestation and afforestation

Reforestation is the process of restoring forests where they have been degraded or cleared
Can occur naturally through seed dispersal and succession or be actively managed through tree planting programs
Afforestation is the process of planting trees in areas where there were no previous forests
Used to combat desertification, improve water retention, and provide economic opportunities through timber production and agroforestry
But, must be carefully planned to avoid disrupting native ecosystems or reducing water availability in dry regions

Tree Identification

Easiest to do with leaves
Can be done with bark/tree shape, but that’s quite a bit harder
Fruit and flowers are helpful too
Field guides are traditional
But there are some other helpful tools too!
- iNaturalist
- PlantSnap
- PictureThis
- LeafSnap
- Pl@ntNet
- TreeSnap
Whatever approach you use, have an idea of what species you are expecting in your study area before doing any work.

Tools of the Trade

Instruments (Dendrometers)
- Measure the growth of a tree
- Diameter tape (D-tape) is most common
  - accurate to 0.1” (in U.S. always measured in inches)
  - two graduated scales: ordinary inches and diameter equivalents
  - most consistent method
- Calipers
  - accurate to 0.1”
  - ideal for small to mid-sized trees
  - take two measurements on decidedly elliptical stems
- Biltmore stick
  - suffers all same problems as the caliper, only more so
  - accurate to ½ inch
  - Used to estimate dbh but often also includes a hypsometer scale to estimate height

Individual Tree Measurement

How do we measure?
- Circumference of trunk at breast height (CBH)
- Height of tree by using a laser/clinometer
- Average crown spread is measured leaf tip to leaf tip
Diameter
- Most frequently measured diameter is Diameter Breast Height, or, DBH for short
- Average stem diameter (in inches!) outside bark of the tree measured at breast height above ground level
- On steep slopes measure on the uphill side of tree
- Trees forking below breast height are treated as two
- Other stem deformities – move above it

Using a clinometer

$h = tan(A) * d$ where h is height, A is angle, and d is distance
With eye height correction , $h = (tan(A) * d) + eyeheight$
$A = 90 - angle$ read on clinometer

Tree surveys

Variable radius plot sampling
- Uses a tool like a prism to select trees based on their diameter and distance from a point
- Often used in forest inventory for quick assessments of basal inventory and volume

Timber cruise

a forest management tool
A way to estimate the quantity and quality of timber in a specific area by systematically measuring sample plots within a forest to collect data on tree species, size, volume, health.
- Helps to plan timber harvests, assess forest value, and make informed management decisions
- Different methods can be used but most common are variable plots, fixed area plots, rectangle plots

Plot sampling

Fixed plots, in which all trees within plot are measured and recorded
- Useful for estimating tree density, species composition, biomass

Line transect sampling

Walking along a straight line and recording trees that intersect or are within a specific distance from the line
- Useful to estimate tree density, species distribution, habitat usage

Systematic sampling

Plots or points are placed in a regular grid pattern across the study area
- Reduces sampling bias and ensures even coverage

Random sampling

Plots or points are placed randomly within the study area
- Helps to avoid biases but may require a large number of samples to be representative

Data logging and graphing

How to plot tree heights and DBH in Excel
And then to compare the results of the four different timber cruise methods!
Input your data into Excel
Select the trees you’d like to chart, go to the ‘Insert’ tab and choose a scatter plot
Right click on the chart
Click 'select data'
Click ‘edit' in the Legend Entry (series) section
Set your x value as your DBH
Set your y value as your height
Click “OK” in the ‘edit series’ tab
Click “OK” in the ‘select data source’ tab
Click on the chart
Select the ‘Axis Titles’ box
Rename the axis titles to match your DBH or height (include unit)
Double click on the heading title and rename it to your chart title
Click on chart
Hover over the ‘trendline’ section to activate more options
Select “More Options” to open the trendline toolbar
Select the Bar chart icon to open the “Format Trendline” panel
Choose the “Linear” trendline option
Click the box next to “Display Equation on chart”