Modules 24, 28-32, and 34 Lecture Slides (1)

Module 24: Land and Water Use

Learning Goals

  • LG 24-1: Explain the tragedy of the commons.

  • LG 24-2: Describe rangeland and forest land management.

  • LG 24-3: Explain the environmental impacts of clear-cutting.

LG 24-1: Tragedy of the Commons

  • Definition:

    • Shared resource use by humans can lead to its depletion if there are no regulations.

  • Key Uses of Land:

    • Food production

    • Providing shelter and resources

    • Aesthetic enjoyment (intrinsic beauty)

  • Problematic Outcomes:

    • Overuse of common resources, leading to degradation.

  • Examples of Commons:

    • Global fisheries

    • Public lands

    • The atmosphere (air pollution and greenhouse gases)

    • Oceans affected by pollution.

  • Externalities:

    • Costs associated with resource degradation that aren't included in purchase prices.

  • Public Land Classification:

    • Protected areas: 14% of terrestrial, 3.4% of marine areas globally.

    • US Public Land Ownership:

      • 42% of land is publicly held.

      • Major organizations: Bureau of Land Management (BLM), United States Forest Service (USFS), National Park Service (NPS), and Fish and Wildlife Service (FWS).

LG 24-2: Rangeland and Forest Land Management

  • Rangelands:

    • Dry, open grasslands mainly for grazing, common in the US.

    • Risks of overgrazing:

      • Loss of biodiversity

      • Soil erosion.

  • Forests:

    • Dominated by trees, also used for logging.

    • National forests provide a sustainable timber source.

LG 24-3: Environmental Impacts of Clear-Cutting

  • Harvesting Methods:

    • Clear-cutting:

      • Involves removing all or nearly all trees in a forest area.

      • Economically beneficial, but causes significant environmental disturbances and erosion.

    • Selective Cutting:

      • Removes a small number of individual trees, creating minimal openings in the forest.

      • Less economically beneficial due to repeated trips and smaller harvest amounts.

  • Ecologically Sustainable Forestry:

    • Practices that avoid harming noncommercial species or soil.

    • Utilizes methods like horse logging for less soil compaction.

    • Balancing economic profit with ecological stability remains a challenge.

  • Reforestation:

    • After cutting, restocking trees helps restore ecosystems and carbon absorption.

  • Policy Regulations:

    • Governed by laws like the National Environmental Policy Act (NEPA) and the Endangered Species Act ensuring environmental considerations in land use.