Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Chapter 56 Conservation Biology and Restoration Ecology

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Tropical forests – Contain some of the greatest concentrations of species – Are being destroyed at an alarming rate Figure 55.1

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Human activities threaten Earth’s biodiversity Rates of species extinction – Are difficult to determine under natural conditions The current rate of species extinction is high – And is largely a result of ecosystem degradation by humans Humans are threatening Earth’s biodiversity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The Three Levels of Biodiversity Biodiversity has three main components – Genetic diversity – Species diversity – Ecosystem diversity Genetic diversity in a vole population Species diversity in a coastal redwood ecosystem Community and ecosystem diversity across the landscape of an entire region Figure 55.2

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Diversity Genetic diversity comprises – The genetic variation within a population – The genetic variation between populations Species diversity – Is the variety of species in an ecosystem or throughout the biosphere

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings An endangered species – Is one that is in danger of becoming extinct throughout its range Threatened species – Are those that are considered likely to become endangered in the foreseeable future

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecosystem Diversity Ecosystem diversity – Identifies the variety of ecosystems in the biosphere – Is being affected by human activity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biodiversity and Human Welfare Human biophilia – Allows us to recognize the value of biodiversity for its own sake Species diversity – Brings humans many practical benefits

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Benefits of Species and Genetic Diversity Many pharmaceuticals – Contain substances originally derived from plants Figure 55.4

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The loss of species – Also means the loss of genes and genetic diversity The enormous genetic diversity of organisms on Earth – Has the potential for great human benefit

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Ecosystem services include – Purification of air and water – Detoxification and decomposition of wastes – Cycling of nutrients – Moderation of weather extremes – And many others

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Four Major Threats to Biodiversity Most species loss can be traced to four major threats – 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 Massive destruction of habitat – Has been brought about by many types of human activity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Introduced Species Introduced species – Are those that humans move from the species’ native locations to new geographic regions

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Introduced species that gain a foothold in a new habitat – Usually disrupt their adopted community (a) Brown tree snake, intro- duced to Guam in cargo (b) Introduced kudzu thriving in South Carolina Figure 55.6a, b

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overexploitation Overexploitation refers generally to the 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 The extermination of keystone species by humans – Can lead to major changes in the structure of communities Figure 55.8

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Population conservation focuses on population size, genetic diversity, and critical habitat Biologists focusing on conservation at the population and species levels – Follow two main approaches

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Small-Population Approach Conservation biologists who adopt the small- population approach – Study the processes that can cause very small populations finally to become extinct

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The Extinction Vortex A small population is prone to positive- feedback loops – That draw the population down an extinction vortex Small population Inbreeding Genetic drift Lower reproduction Higher mortality Loss of genetic variability Reduction in individual fitness and population adaptability Smaller population Figure 55.9

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The key factor driving the extinction vortex – Is the loss of the genetic variation necessary to enable evolutionary responses to environmental change

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Minimum Viable Population Size The minimum viable population (MVP) – Is the minimum population size at which a species is able to sustain its numbers and survive

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A population viability analysis (PVA) – Predicts a population’s chances for survival over a particular time – Factors in the MVP of a population

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Effective Population Size A meaningful estimate of MVP – Requires a researcher to determine the effective population size, which is based on the breeding size of a population

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Declining-Population Approach The declining-population approach – Focuses on threatened and endangered populations that show a downward trend, regardless of population size – Emphasizes the environmental factors that caused a population to decline in the first place

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Steps for Analysis and Intervention The declining-population approach – Requires that population declines be evaluated on a case-by-case basis – Involves a step-by-step proactive conservation strategy

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 Fragmentation and Edges The boundaries, or edges, between ecosystems – Are defining features of landscapes (a) Natural edges. Grasslands give way to forest ecosystems in Yellowstone National Park. (b) Edges created by human activity. Pronounced edges (roads) surround clear-cuts in this photograph of a heavily logged rain forest in Malaysia. Figure 55.14a, b

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 Research on fragmented forests has led to the discovery of two groups of species – Those that live in forest edge habitats and those that live in the forest interior Figure 55.15

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bioremediation – Is the use of living organisms to detoxify ecosystems

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biological Augmentation Biological augmentation – Uses organisms to add essential materials to a degraded ecosystem

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Exploring Restoration The newness and complexity of restoration ecology – Require scientists to consider alternative solutions and adjust approaches based on experience

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Exploring restoration worldwide Truckee River, Nevada.Kissimmee River, Florida. Equator Figure 55.22

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Tropical dry forest, Costa Rica. Succulent Karoo, South Africa. Rhine River, Europe. Coastal Japan. Figure 55.22

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Sustainable Biosphere Initiative The goal of this initiative is to define and acquire the basic ecological information necessary – For the intelligent and responsible development, management, and conservation of Earth’s resources