Forestry Chapter 10

Forests Vary in Their Make-Up, Age, and Origins Old-growth or primary forest Has not been seriously disturbed by human activities for 200 years or more 36% of world’s forests

Forests Vary in Their Make-Up, Age, and Origins Second-growth forest Tree plantation, tree farm or commercial forest

Rotation Cycle of Cutting and Regrowth of a Monoculture Tree Plantation

Figure 10.3 Short (25- to 30-year) rotation cycle of cutting and regrowth of a monoculture tree plantation used in modern industrial forestry. In tropical countries, where trees can grow more rapidly year-round, the rotation cycle can be 6–10 years. Old-growth or second-growth forests are clear-cut to provide land for growing most tree plantations (see photo, right). Question: What are two ways in which this process can degrade an ecosystem? Fig. 10-3a, p. 216

Figure 10.3 Short (25- to 30-year) rotation cycle of cutting and regrowth of a monoculture tree plantation used in modern industrial forestry. In tropical countries, where trees can grow more rapidly year-round, the rotation cycle can be 6–10 years. Old-growth or second-growth forests are clear-cut to provide land for growing most tree plantations (see photo, right). Question: What are two ways in which this process can degrade an ecosystem? Fig. 10-3b, p. 216

Natural Capital: Major Ecological and Economic Services Provided by Forests

Science Focus: Putting a Price Tag on Nature’s Ecological Services Forests valued for ecological services Nutrient cycling Climate regulation Erosion control Waste treatment Recreation Raw materials $4.7 Trillion per year

Estimated Annual Global Economic Values of Ecological Services Provided by Forests

Unsustainable Logging is a Major Threat to Forest Ecosystems (1) Increased erosion Sediment runoff into waterways Habitat fragmentation Loss of biodiversity Invasion by nonnative pests and disease

Natural Capital Degradation: Building Roads into Previously Inaccessible Forests

Tree Harvesting Methods Major tree harvesting methods: Selective cutting Clear-cutting Strip cutting

Figure 10.6 Major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why? Fig. 10-6a, p. 219

Figure 10.6 Major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why? Fig. 10-6b, p. 219

Figure 10.6 Major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why? Fig. 10-6c, p. 219

(a) Selective cutting (c) Strip cutting Clear stream (b) Clear-cutting Muddy stream Uncut Cut 1 year ago Dirt road Cut 3–10 years ago Clear stream Figure 10.6 Major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why? Stepped Art Fig. 10-6a, p. 219

Clear-Cut Logging in Washington State, U.S.

Trade-offs: Advantages and Disadvantages of Clear-Cutting Forests

Fires Can Affect Forest Ecosystems Some ecosystems rely on fire Part of the natural cycle Surface fires Usually burn leaf litter and undergrowth Prevent more destructive fires Allow for some plants (conifers) to release seeds Controlled burns (prescribed fires)

Fire, Insects, and Climate Change Can Threaten Forest Ecosystems Crown fires Occurs in the treetops Extremely hot: burns whole trees Kill wildlife

Surface and Crown Fires

U.S. Forest Invading Nonnative Insect Species and Disease Organisms

We Have Cut Down Almost Half of the World’s Forests Deforestation Tropical forests Cover 6% of earth’s land area Home to approx. 50% of plants and animal species Especially in Latin America, Indonesia, and Africa Boreal forests Important for producing O2 and removing CO2 Especially in Alaska, Canada, Scandinavia, and Russia

Satellite Images of Amazon Deforestation between 1975 and 2001

Natural Capital Degradation: Extreme Tropical Deforestation in Thailand

Natural Capital Degradation: Harmful Environmental Effects of Deforestation

Case Study: Many Cleared Forests in the United States Have Grown Back Forests of the eastern United States decimated between 1620 and 1920 Grown back naturally through secondary ecological succession Biologically simplified tree plantations reduce biodiversity

Major Causes of the Destruction and Degradation of Tropical Forests

Solution: Sustainable Forestry

We Can Reduce the Demand for Harvested Trees Improve the efficiency of wood use Make tree-free paper Use recycled paper

Kenaf

Case Study: Deforestation and the Fuelwood Crisis Developing countries rely on fuelwood Results in deforestation Haiti: ecological disaster for unsustainable forestry

Solutions: Sustaining Tropical Forests

Managing Grasslands Rangelands Pastures Overgrazing Rotational Grazing Riparian Zones

National Parks Face Many Environmental Threats Worldwide: 1100 major national parks Parks in developing countries Greatest biodiversity Only 1% protected against Illegal animal poaching Illegal logging and mining

Case Study: Stresses on U.S. Public Parks 58 Major national parks in the U.S. Biggest problem may be popularity Noise Congestion Pollution Damage or destruction to vegetation and wildlife Repairs needed to trails and buildings

Natural Capital Degradation: Damage From Off-Road Vehicles

Solutions: National Parks

Science Focus: Effects of Reintroducing the Gray Wolf to Yellowstone National Park Gray wolves prey on elk and push them to a higher elevation Regrowth of aspen, cottonwoods, and willows Increased riparian areas Reduced the number of coyotes Fewer attacks on cattle

Nature Reserves Occupy Only a Small Part of the Earth’s Land Conservationists’ goal: protect 20% of the earth’s land Cooperation between government and private groups Nature Conservancy Eco-philanthropists Developers and resource extractors opposition

Land Trusts

The Ecosystem Approach Argument that the best way to sustain biodiversity is to protect threatened habitats and ecosystem services. Whole ecosystem or whole habitat approach Don’t just focus on a single species

Designing and Connecting Nature Reserves Large versus small reserves The buffer zone concept Habitat corridors between isolated reserves

Solutions: A Model Biosphere Reserve

Visitor education center Biosphere Reserve Core area Research station Visitor education center Figure 10.24 Solutions: a model biosphere reserve. Each reserve contains a protected inner core surrounded by two buffer zones that local and indigenous people can use for sustainable logging, growing limited crops, grazing cattle, hunting, fishing, and ecotourism. Question: Do you think some of these reserves should be free of all human activity, including ecotourism? Why or why not? Buffer zone 1 Human settlements Buffer zone 2 Fig. 10-24, p. 237

Wildlife Corridors/Habitat Corridors

Case Study: Costa Rica—A Global Conservation Leader 1963–1983: cleared much of the forest 1986–2006: forests grew from 26% to 51% Goal: to reduce net carbon dioxide emissions to zero by 2021 Eight zoned megareserves Designed to sustain around 80% of Costa Rica’s biodiversity

Solutions: Costa Rica: Parks and Reserves—Megareserves

Nicaragua Caribbean Sea Costa Rica Panama Pacific Ocean Figure 10.25 Solutions: Costa Rica has consolidated its parks and reserves into eight zoned megareserves designed to sustain about 80% of the country’s rich biodiversity. Green areas are protected reserves and yellow areas are nearby buffer zones, which can be used for sustainable forms of forestry, agriculture, hydropower, hunting, and other human activities. Pacific Ocean National parkland Buffer zone Fig. 10-25, p. 238

Protecting Wilderness Is an Important Way to Preserve Biodiversity Pros Cons

Case Study: Controversy over Wilderness Protection in the United States Wilderness Act of 1964 Roadless Rule 2005: end of roadless areas within the national forest system

DEFINITION OF WILDERNESS (c) A wilderness, in contrast with those areas where man and his own works dominate the landscape, is hereby recognized as an area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain. An area of wilderness is further defined to mean in this Act an area of undeveloped Federal land retaining its primeval character and influence, without permanent improvements or human habitation, which is protected and managed so as to preserve its natural conditions and which (1) generally appears to have been affected primarily by the forces of nature, with the imprint of man's work substantially unnoticeable; (2) has outstanding opportunities for solitude or a primitive and unconfined type of recreation; (3) has at least five thousand acres of land or is of sufficient size as to make practicable its preservation and use in an unimpaired condition; and (4) may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value

We Can Use a Four-Point Strategy to Protect Ecosystems Map global ecosystems; identify species Locate and protect most endangered species Restore degraded ecosystems Development must be biodiversity-friendly

Biodiversity Hotspots Biodiversity hotspot - a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction. 

Endangered Natural Capital: Biodiversity Hotspots in the U.S.

Case Study: A Biodiversity Hot Spot in East Africa Eastern Arc Mountains of Tanzania, Africa Highest concentration of endangered species on earth Threatened due to Destruction of forests by farmers and loggers Hunting Fires

Case Study: Madagascar

We Can Rehabilitate and Restore Ecosystems That We Have Damaged (1) Study how natural ecosystems recover Restoration Rehabilitation Replacement Creating artificial ecosystems

We Can Rehabilitate and Restore Ecosystems That We Have Damaged (2) How to carry out most forms of ecological restoration and rehabilitation Identify what caused the degradation Stop the abuse Reintroduce species, if possible Protect from further degradation

Case Study: Wetland Mitigation Banking Wetlands are protected Permits to build on wetlands usually require wetland mitigation https://www.youtube.com/watch?v=334LSNKp2AQ