5.17 - Sustainable Forestry

Learning Objectives

I. Ecologically Sustainable Forestry Practices

• Selective cutting or strip cutting: Cutting only the oldest trees, which avoids clear cutting and leaving the ecosystem completely bare.
• Benefits: Preserves soil and animal habitats. The remaining trees anchor the soil better, which prevents soil erosion and keeps streams from getting muddy or turbid. Strip cutting achieves similar results by leaving patches of trees in place.

• Minimizing soil compaction: Using human or animal labor, like pack animals such as horses, is preferred over large logging machines. Big machines cause serious soil compaction, which increases erosion.

• Replanting native species: When replanting harvested areas, use the same species naturally found there. This preserves biodiversity and habitat for animals that depend on those specific trees.

II. Sustainable Wood Use and Reforestation

• Recycled and repurposed wood: Using recycled wood or repurposing wooden items, like turning pallets into furniture, decreases demand for newly logged trees. Old wood can also be chipped into mulch for gardens or agriculture.

• Buying sustainably harvested wood: Look for wood and paper certified by groups like the Forest Stewardship Council (FSC), which checks that forests are logged with ecologically sustainable methods, like selective cutting and replanting. Buying certified wood rewards companies that protect forests.

• Reforestation: Replanting forests in areas that have been deforested, ideally with the same species of trees.
• Benefits: Restores habitats and biodiversity, and sequesters carbon from the atmosphere.

• Selective cutting of diseased trees: Removing diseased trees preserves the forest by taking out the tree acting as a host or breeding ground for the bacteria, fungus, or pest. Cutting those trees keeps the disease from spreading through the rest of the population.

• Integrated pest management (IPM) in forests: Combining methods to control forest insects and pathogens with as few chemicals as possible (5.14).
• Real example: To fight the emerald ash borer, an invasive beetle that has killed hundreds of millions of ash trees in North America, the USDA releases tiny parasitic wasps that attack the beetle's eggs and larvae, states restrict moving firewood (which spreads the beetle), infested trees are removed, and only high-value trees get targeted insecticide injections.

III. Fire Suppression and Prescribed Burns

• Consequences of fire suppression:
• Suppression prevents natural fires from burning up dead biomass, which then accumulates, especially in dry ecosystems.
• That buildup of fuel makes future fires much worse.
• Dead biomass traps nutrients so they are not recycled back into the soil for future plant growth.
• Dead trees and grasses also become breeding grounds for pests and diseases.

• Solution, prescribed burns: Small, controlled fires set on purpose to reduce the accumulation of dead biomass.
• Mitigation measures: Fire breaks are dug, workers monitor the fire, and wind direction is taken into account to keep it from spreading.
• Benefits: Promotes nutrient cycling by burning dead organisms and returning nutrients to the soil. It prevents future fuel buildup and encourages new growth of green, healthy living plants, which do not burn as easily, so future fires are less severe.
• Real example of the risk: In 2022, two Forest Service burns in New Mexico escaped control and merged into the Hermits Peak/Calf Canyon Fire, the largest wildfire in the state's history. That's why prescribed burns are only done when the weather, humidity, and wind are right.