Biosphere Daily Earth Science Environment Repost

Extractive versus sustainable logging

Politicians are jumping on the bandwagon of planting trees, but let’s take a step back and look at the bigger picture. Understanding the role of planting new forests requires a look at different models of forest management. Accordingly, there are two basic models: extractive logging versus sustainable logging. 

Forest are more than trees, though. Forest are ecosystems that integrate terrestrial and aquatic/hydrologic components, providing a habitat for biodiversity.  The characteristics of a forest are a function of climate and geography. But soil is the foundation upon which a healthy forest rests because carbon exchange between the trees and the water systems occurs via the soil. So, healthy soil is an indicator of a healthy forest ecosystem. 

Sustainable logging preserves the soil quality and the biodiversity of a forest. In contrast, extractive logging damages the natural balance of a healthy ecosystem.  Timber harvesting generally divides into three practices: clearcutting, shelterwood, and selection systems. This classification scheme reflects the needs of the species requiring replanting versus considering the total needs of the forest ecosystem. Clear cutting removes all the trees and provides open space for species of seedlings that need direct sunlight and warmth.

Selection systems thin overly dense forest to improve their health but retain canopy for partial shade on the forest floor. Species that can thrive in cooler shady conditions are then replanted. Shelterwood is somewhere in between the clearcutting and selection systems.

Managing carbon    

Managing trees as a carbon sink has three major components: maintenance, restoration, and growth. These are listed in an order reflecting payout time. Maintaining a healthy forest is low hanging fruit. The carbon sequestration capacity of the forest then holds steady or increases with good forest maintenance. 

Restoration starts engaging with tree planting as destroyed or degraded portions of a forest are replanted. Good restoration seeks to restore portions of a forest back to its original state by reintroducing species of trees that originally grew there. A mature forest consists of species that thrive in the particular climatic and geologic conditions of the restoration area, so the restored forest merges with the existing ecosystem. 

Growth through planting new forests is the longest payout time since the forest must grow completely from seedlings and establish a new ecosystem. Planting trees is a good practice, but it is part of a forest management system and not a stand-alone solution.

Managing ecosystems

The Tongass National Forest of southern Alaska is the largest forest in the U.S. It has a history of over logging that slowed substantially in the 1990s. But increased logging in this forest is back on the agenda for the current administration. 

Prior to the arrival of Europeans, the native North Americans managed the land in a circular or sustainable manner for thousands of years. The land was rich and provided sustenance, but the land reuqiured maintenance to sustain future generations. 

This is a very different model that the commercial views of European settlers, where manifest destiny was the operating philosophy. Under this philosophy, land can be used to extract wealth and value, and when the resources are completely stripped, then the business moves on to new undeveloped lands. This practice is essentially the slash and burn farming technique being applied today over much of the Amazon Forest in Brazil.

The system is commercially lucrative since maximum resources are being extracted from an ecosystem. When the ecosystem falls into decline and ruin, then the commercial operation moves on to the next ecosystem. In a recent article Saul Elbein of National geographic wrote the following about logging in the Tongass: 

The clear-cuts also brought a sort of localized climate change distinct from the global one, as the trees that regulated the ecosystem disappeared, and the bare slopes left behind, washed by the constant rain, disgorged sediment into once-clear streams. Bark sloughed off from log rafts settled to the bottom and fermented into toxic methylmercury, killing the seafloor… Once-lucrative salmon streams and their attached fisheries expired as erosion from the bare hills clogged the once-clear pools, or as the loss of the canopy left them unprotected from the sun.”

Time to move on to a new patch of forest?

Sustaining Ecosystems

Forests can be harvested sustainably, but it is more than the forest that must be sustained. At the heart of good forest practice and good environmental policy are practices that sustain the local ecosystems. But this approach clashes with our traditional extractive approach to the land. The economics of pollution drive companies to maximize profits today and defer the real costs to the future for someone else to absorb. 

Carrying the added costs of environmentally sustainable logging operations does negatively impact the economics and profitability of any project. But should society subsidize commercial operations by letting them defer and transfer the true costs to future taxpayers or local inhabitants? It is possible that the cost of sustainable logging may be too high in some areas to make it profitable. However the answer is not to allow companies to defer costs. The answer is to wait until the market does support a profitable business using sustainable logging practices. 


Tongass National Forest: The good, the better, and the beautiful (Source: ArcheanWeb) – Also:

The economics of environmental pollution (Source: ArcheanWeb) – Also:


 A new way to profit from ancient Alaskan forests—leave them standing (By SAUL ELBEIN; National Geographic) – Also:

Timber harvest methods (By Bill Cook; Michigan State University) – Also:

Feature Image: Tawau-District Sabah Logging-Camp-10 (By Uwe Aranas) (Modified) –   – This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. –

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.