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Sustaining Terrestrial Biodiversity: Sustaining Terrestrial Biodiversity: The Ecosystem ApproachThe Ecosystem Approach

G. Tyler Miller’sG. Tyler Miller’sLiving in the EnvironmentLiving in the Environment14th Edition14th Edition

Chapter 11Chapter 11

Shohail Motahir ChoudhuryShohail Motahir Choudhury

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Key ConceptsKey ConceptsKey ConceptsKey Concepts

Human land useHuman land use

Types and uses of US public landsTypes and uses of US public lands

Forests and forest managementForests and forest management

Implications of deforestationImplications of deforestation

Management of parksManagement of parks

Establishment and management of nature preservesEstablishment and management of nature preserves

Importance of ecological restorationImportance of ecological restoration

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Human Human Activities Activities and and BiodiversityBiodiversity

Biodiversity

Increase FactorsIncrease Factors

•Middle stages of succession

•Moderate environmental disturbance

•Small changes in environmental conditions

•Physically diverse habitat

•Evolution

Decrease FactorsDecrease Factors

•Extreme environ- mental conditions

•Large environmental disturbance

•Intense environ- mental stress

•Severe shortages of key resources

•Nonnative species introduction

•Geographic isolation

BiodiversityBiodiversity

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Human PopulationSize and resource use

Human ActivitiesAgriculture, industry, economic

production and consumption, recreation

Indirect Effects

Direct Effects

Degradation and destruction of natural ecosystems

Alteration of natural chemicalcycles and energy flows

Changes in number and distribution of species

Pollution of air, water, and soil

Climate change

Loss of biodiversity

5Projected Status of Biodiversity1998–2018

Critical and endangered Threatened Stable or intact

NORTHAMERICA

AtlanticOcean

ANTARCTICA

EUROPE

AFRICA

ASIA

SOUTHAMERICA AUSTRALIA

PacificOcean

Antarctic Circle

PacificOcean

Tropic of Cancer

Tropic of CapricornIndianOcean

150°90°60°E0°30°W90°120°150°0°

60°

30°N

30°S

60°

Arctic CircleArctic Circle

Natural Capital DegradationNatural Capital Degradation

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Why should we care about Why should we care about biodiversity? biodiversity?

Intrinsic valueIntrinsic value

Instrumental valueInstrumental value

or Existence valueor Existence value

Aesthetic valueAesthetic value

Bequest valueBequest value

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The Species ApproachThe Species Approach The Ecosystem ApproachThe Ecosystem Approach

Goal

Protect species frompremature extinction

Strategies• Identify

endangered species

• Protect their critical habitats

Tactics

• Legally protect endangered species

• Manage habitat

• Propagate endangered species in captivity

• Reintroduce species into suitable habitats

Goal

Protect populations ofspecies in their naturalhabitats

Strategy

Preserve sufficient areasof habitats in differentbiomes and aquaticsystems

Tactics• Protect habitat areas

through private purchase or government action

• Eliminate or reduce populations of alien species from protected areas

• Manage protected areas to sustain native species

• Restore degraded ecosystems

Solutions Solutions for for Protecting Protecting BiodiversityBiodiversity

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Management of ForestsManagement of Forests

Old-growth (frontier) forests 22%Old-growth (frontier) forests 22%

Second-growth forests 63%Second-growth forests 63%

Tree farms/plantation 5%Tree farms/plantation 5%

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Managing and Sustaining ForestsManaging and Sustaining Forests

Ecological Importance of ForestsEcological Importance of Forests

Food webs and energy flowFood webs and energy flow

Protect soils from erosionProtect soils from erosion

Local and regional climateLocal and regional climate

Numerous habitats and nichesNumerous habitats and niches

Air purificationAir purification

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Economic Importance of ForestsEconomic Importance of Forests

FuelwoodFuelwood

LumberLumber

PaperPaper

Livestock grazingLivestock grazing

Mineral extraction and recreationMineral extraction and recreation

Managing and Sustaining ForestsManaging and Sustaining Forests

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Forest ManagementForest Management

Even-aged managementEven-aged management

Uneven-aged managementUneven-aged management

Improved diversityImproved diversity

Sustainable productionSustainable production

Multiple-useMultiple-use

Rotation cycleRotation cycle

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Management Strategies: Rotation CyclesManagement Strategies: Rotation Cycles

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Roads Lead to Forest DegradationRoads Lead to Forest Degradation

Increased erosion and runoffIncreased erosion and runoff

Habitat fragmentationHabitat fragmentation

Pathways for exotic speciesPathways for exotic species

Accessibility to humansAccessibility to humans

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Harvesting TreesHarvesting Trees

Selective cuttingSelective cutting

High-gradingHigh-grading

Shelterwood cuttingShelterwood cutting

Seed-tree cuttingSeed-tree cutting

Clear-cutting Clear-cutting

Strip cuttingStrip cutting

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Trade-Offs

Clear-Cutting Forests

Advantages Disadvantages

Higher timber yields

Maximum economic returnin shortest time

Can reforest with genetically improved fast-growing trees

Short time to establish newstand of trees

Needs less skill and planning

Best way to harvest treeplantations

Good for tree species needing full or moderate sunlightfor growth

Reduces biodiversity

Disrupts ecosystem processes

Destroys and fragments some wildlife habitats

Leaves moderate to large openings

Increases soil erosion

Increases sediment water pollution and flooding when done on steep slopes

Eliminates most recreational value for several decades

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Solutions

Sustainable Forestry

•Grow more timber on long rotations

•Rely more on selective cutting and strip cutting

•No clear-cutting, seed-tree, or shelterwood cuttingon steeply sloped land

•No fragmentation of remaining large blocks of forest

•Sharply reduce road building into uncut forest areas

•Leave most standing dead trees and fallen timber for wildlife habitat and nutrient recycling

•Certify timber grown by sustainable methods

•Include ecological services of trees and forests inestimating economic value

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FireFire

Surface firesSurface fires Crown firesCrown fires

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Tropical Deforestation: ConsequencesTropical Deforestation: Consequences

Rapid and increasing

Loss of biodiversity

Loss of resources (e.g., medicines)

Contributes to global warming

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•Oil drilling•Mining•Flooding from dams•Tree plantations•Cattle ranching•Cash crops•Settler farming•Fires•Logging•Roads

•Not valuing ecological services•Exports•Government policies•Poverty•Population growth

Secondary Causes

Basic Causes

Causes of tropical Causes of tropical forest degradationforest degradation

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Figure 11-19Page 213Protect most diverse andendangered areas

Educate settlers about sustainableagriculture and forestry

Phase out subsidies that encourageunsustainable forest use

Add subsidies that encouragesustainable forest use

Protect forests with debt-for-natureswaps, conservation easements,and conservation concessions

Certify sustainably grown timber

Reduce illegal cutting

Reduce poverty

Slow population growth

Reforestation

Rehabilitation of degradedareas

Concentrate farming andranching on already-clearedareas

RestorationPrevention

Solutions

Sustaining Tropical Forests

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Ecological RestorationEcological Restoration

Restoration Restoration

Rehabilitation Rehabilitation

Replacement Replacement

Creating artificial ecosystemsCreating artificial ecosystems

Remediation Remediation

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Ecological Restoration: Basic PrinciplesEcological Restoration: Basic Principles

Mimic nature Mimic nature

Recreate lost niches Recreate lost niches

Control nonnative species Control nonnative species

Reconnect small patchesReconnect small patches

Rely on pioneer species Rely on pioneer species

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Individuals MatterIndividuals Matter

Wangari MaathaiWangari Maathai

Green Belt MovementGreen Belt Movement

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What Can You Do?

Sustaining Terrestrial Biodiversity

•Plant trees and take care of them.

•Recycle paper and buy recycled paper products.

•Buy wood and wood products made from trees thathave been grown sustainably.

•Help rehabilitate or restore a degraded area of forest or grassland near your home.

•When building a home, save all the trees and as muchnatural vegetation and soil as possible.

•Landscape your yard with a diversity of plants naturalto the area instead of having a monoculture lawn.