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Chapter 55 Conservation Biology Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Biodiversity Crisis – Conservation biology integrates the following fields to conserve biological diversity at all levels – Ecology – Evolutionary biology – Physiology – Molecular biology – Genetics – Behavioral ecology Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Restoration ecology applies ecological principles – In an effort to return degraded ecosystems to conditions as similar as possible to their natural state Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Tropical forests – Greatest concentrations of species – Are being destroyed at an alarming rate Figure 55.1 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Throughout the biosphere, human activities – Are altering ecosystem processes on which we and other species depend Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • The current rate of species extinction is high – And is largely a result of ecosystem degradation by humans • threatening Earth’s biodiversity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The Three Levels of Biodiversity • Genetic diversity • Species diversity • Ecosystem diversity Genetic diversity in a vole population Species diversity in a coastal redwood ecosystem Figure 55.2 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Community and ecosystem diversity across the landscape of an entire region • Endangered species – in danger of becoming extinct throughout its range • Threatened species – likely to become endangered Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • 12% birds, 24% mammals are threatened • 20% fish have become extinct during historic times or are threatened • 32% amphibians near extinction or endangered • At current rates 50% of plants and animals will become extinct Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Harvard biologist E. O. Wilson has identified the Hundred Heartbeat Club – Fewer than 100 individuals Philippine eagle ) Chinese river dolphin Figure 55.3a–c Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Javan rhinoceros Ecosystem Diversity • The variety of ecosystems in the biosphere is being affected by human activity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Benefits of Species and Genetic Diversity • Many pharmaceuticals originally derived from plants Figure 55.4 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecosystem services • Purification of air and water • Detoxification and decomposition of wastes • Cycling of nutrients • Moderation of weather extremes • ……….. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Four Major Threats to Biodiversity • Habitat destruction • Introduced species • Overexploitation • Disruption of “interaction networks” Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Habitat Destruction • Human alteration of habitat is the single greatest threat to biodiversity throughout the biosphere Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Many natural landscapes have been broken up – Fragmenting habitat into small patches Figure 55.5 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Introduced Species • Human introduced Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Pennsylvania Invasive Plants (partial list) • Flowers • Scientific NameCommon NameNotesAegopodium podagraria GoutweedCommonly planted in the past and escaped; spreads aggressively by rootsAlliaria petiolata Garlic mustard Invasive in many states; spreading aggressively in woodlands by seedCarduus nutans Musk thistle PA noxious WeedCirsium arvense Canada thistle PA noxious Weed Cirsium vulgare Bull thistle PA noxious Weed Datura stramonium JimsonweedSometimes cultivated; spreads by seed, PA Noxious WeedGalega officinalis GoatsruePA and Federal Noxious WeedHeracleum mantegazzianum Giant hogweed PA and Federal Noxious Weed, sap can cause burning blistersHesperis matronalis Dame's rocket Planted in gardens; escaped and naturalized along roads; spreads by seedLythrum salicaria, L. virgatumPurple loosestife Garden escape which has become invasive in many states; PA noxious WeedMyriophyllum spicatum Eurasian water-milfoil Invasive in many states; aquaticOrnithogallum nutans, umbellatumStar-of-BethlehemCommon garden plant which has widely escapedPastinaca sativa Wild parsnip Found commonly along roadsides; widespread and abundant; spread by seedPerilla frutescens Beefsteak plant Garden escape; widespread mostly along roadsides; spread by seedPolygonum (Falopia) cuspidatumJapanese knotweed Invasive in many states; difficult to control; spreads by roots and seedsRanunculus ficaria Lesser celandine Spreads by roots and shoots; can be very aggressive in wetlandsTrapa natans Water chestnut Wetland plant; should not be introduced as it will escape, spread, and naturalize Grasses • Scientific NameCommon NameNotesBromus tectorum CheatgrassAnnual grass; invasive throughout the west; spreads by seedMicrostegium vimineum Japanese stilt grassAnnual grass; invasive in many states; spreading through woodlands by seed * Miscanthus sinensis Maiden grass Commonly planted ornamental grass which can escape and spread by seedPhalaris arundinacea Reed canary grassAggressive wetland grass; native and introduced strains; widespread and abundant Phragmites australis Common reed Native and introduced strains; wetland grass which can form huge coloniesSorghum bicolor ssp. drummondiiShattercanePA noxious WeedSorghum halepense Johnson grassPA noxious Weed; spreads by roots and seedsShrubs • Scientific NameCommon NameNotes* Berberis thunbergii Japanese barberry Escaped from cultivation and invasive in many states; spread by birdsBerberis vulgaris European barberry Escaped from cultivation; spread by birdsElaegnus angustifolia Russian olive Escaped from plantings and invasive in many states; spread by birdsElaeagnus umbellata Autumn olive Escaped from plantings and invasive in many states; rapidly spread by birds * Euonymus alatus Winged Euonymus Escaped from plantings; invasive in moist forestsLigustrum obtusifoliumBorder privet Escaped from cultivation; seeds spread by birdsLigustrum vulgare Common privet Planted very commonly in the past and escaped; invasive in many statesLonicera maackii Amur honeysuckle Escaped from plantings; seeds spread by birdsLonicera morrowii Morrow's honeysuckle Escaped from plantings and invasive in many states; seeds spread by birdsLonicera morrowii x tataricaBell's honeysuckle Escaped from cultivationLonicera standishii Standish honeysuckle Escaped from plantings; seeds spread by birds Lonicera tartarica Tartarian honeysuckle Escaped from plantings; seeds spread by birds Rhamnus catharticus Common buckthorn Becoming a problem in PARhamnus frangula Glossy buckthorn Becoming a problem in PARubus phoenicolasius WineberryCommon bramble; not cultivated; spread by seedRosa multiflora Multiflora rose Invasive in many states; seeds spread by birds; PA noxious Weed* Spiraea japonica Japanese spiraea Frequently planted; escaped in some areas* Viburnum opulus var. opulusGuelder rose Resembles native Viburnum trilobum which it replaces; both are cultivated and plantedTrees • Scientific NameCommon NameNotes* Acer platanoides Norway maple Commonly planted and escaped; invasive in many states; wind spreads prolific seedsAcer pseudoplatanus Sycamore maple Escaped from cultivation; wind spreads prolific seedsAilanthus altissima Tree-ofheavenInvasive in many states; wind spreads prolific seedsPaulownia tomentosa Empress tree Prolific seeds fall to start new seedlings* Pyrus calleryana Callery pear Commonly planted street tree; becoming a problem as an escapeUlmus pumilaSiberian elm Escaped from cultivationVines • Scientific NameCommon NameNotesAkebia quinata Fiveleaf akebia Escaped from cultivation Ampelopsis brevipedunculataPorcelainberryEscaped from cultivation Celastrus orbiculatus Oriental bittersweet Escaped from cultivation and invasive in many states; spreading rapidly (by birds)Lonicera japonica Japanese honeysuckle Invasive in many statesPolygonum perfoliatum Mile-a-minute vine Range expanding; PA Noxious WeedPueraria lobata KudzuInvasive in many states; PA Noxious Weed Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Introduced species disrupt their adopted community (a) Brown tree snake, introduced to Guam in cargo Figure 55.6a, b (b) Introduced kudzu thriving in South Carolina Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overexploitation • Human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • The fishing industry – Has caused significant reduction in populations of certain game fish Figure 55.7 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Disruption of Interaction Networks • Extermination of keystone species by humans Figure 55.8 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The Extinction Vortex • A small population is prone to positivefeedback loops that draw the population down an extinction vortex Small population Inbreeding Genetic drift Lower reproduction Higher mortality Reduction in individual fitness and population adaptability Figure 55.9 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Smaller population Loss of genetic variability Case Study: Analysis of Grizzly Bear Populations • Long-term study of grizzly bears in Yellowstone National Park Figure 55.11 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Grizzly bear population has grown substantially in the past 20 years 150 Females with cubs Number of individuals Cubs 100 50 0 1973 Figure 55.12 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1991 1982 Year 2000 Case Study: Decline of the Red-Cockaded Woodpecker • Require specific habitat factors for survival • Forced into decline by habitat destruction (a) A red-cockaded woodpecker in a longleaf pine. (b) Forest that can sustain birds has low undergrowth. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings (c) Forest that cannot sustain birds has high, dense undergrowth. Fragmentation and Edges • Defining features of landscapes (a) Grasslands give way to forest ecosystems in Yellowstone National Park. (b) Figure 55.14a, b Pronounced edges (roads) surround clear-cuts in this photograph of a heavily logged rain forest in Malaysia. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Weighing Conflicting Demands • Conserving species often requires resolving conflicts between the habitat needs of endangered species and human demands Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • As habitat fragmentation increases – And edges become more extensive, biodiversity tends to decrease Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Corridors That Connect Habitat Fragments • A narrow strip of quality habitat connecting otherwise isolated patches Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Artificial corridor Figure 55.16 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Establishing Protected Areas • Slow the loss of biodiversity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Finding Biodiversity Hot Spots • A relatively small area with an exceptional concentration of endemic species and a large number of endangered and threatened species Terrestrial biodiversity hot spots Equator Figure 55.17 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Nature Reserves • Biodiversity islands in a sea of habitat degraded to varying degrees by human activity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • In some cases the size of reserves is smaller than the actual area needed to sustain a population 0 50 100 Kilometers 42 Gallatin R. Madison R. 43 Montana Wyoming Yellowstone National Park Montana Idaho Shoshone R. 41 Grand Teton National Park Figure 55.18 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Wyoming Idaho 40 Biotic boundary for short-term survival; MVP is 50 individuals. Biotic boundary for long-term survival; MVP is 500 individuals. Restoration ecology • Attempts to restore degraded ecosystems to a more natural state • The larger the area disturbed the longer the time that is required for recovery Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bioremediation • The use of living organisms to detoxify ecosystems Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biological Augmentation • Uses organisms to add essential materials to a degraded ecosystem Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings restoration worldwide Equator Figure 55.22 Truckee River, Nevada. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Kissimmee River, Florida. Figure 55.22 Tropical dry forest, Costa Rica. Succulent Karoo, South Africa. Rhine River, Europe. Coastal Japan. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sustainable development • Seeks to improve the human condition while conserving biodiversity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sustainable Biosphere Initiative • Intelligent and responsible development, management, and conservation of Earth’s resources Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Case Study: Sustainable Development in Costa Rica • Success in conserving tropical biodiversity has involved partnerships between the government, other organizations, and private citizens Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Human living conditions in Costa Rica have improved along with ecological conservation 200 80 Life expectancy 70 150 60 100 50 50 40 0 30 1900 Figure 55.23 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1950 Year 2000 Life expectancy (years) Infant mortality (per 1,000 live births) Infant mortality Biophilia and the Future of the Biosphere • Our modern lives – Are very different from those of early humans who hunted and gathered and painted on cave walls Figure 55.24a (a) Detail of animals in a Paleolithic mural, Lascaux, France Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • But our behavior – Reflects remnants of our ancestral attachment to nature and the diversity of life, the concept of biophilia Figure 55.24b (b) Biologist Carlos Rivera Gonzales examining a tiny tree frog in Peru Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings • Our innate sense of connection to nature – May eventually motivate a realignment of our environmental priorities Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings