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 55 Conservation Biology and Restoration Ecology

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The 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 – 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 – difficult to determine under natural conditions The current rate of species extinction is high – largely a result of ecosystem degradation by humans 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 Genetic, Species, and Diversity Genetic diversity comprises – The genetic variation within a population – The genetic variation between populations Species diversity the variety of species in an ecosystem or throughout the biosphere Ecosystem diversity Identifies variety of ecosystems in the biosphere Is being affected by human activity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings An endangered species – one that’s in danger of becoming extinct throughout its range Threatened species – those that are considered likely to become endangered in the foreseeable future Conservation biologists: concerned about species loss Due to number of alarming stats regarding extinction & biodiversity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Harvard biologist E. O. Wilson has identified the Hundred Heartbeat Club – Species that number fewer than 100 individuals and are only that many heartbeats from extinction (a) Philippine eagle (b) Chinese river dolphin (c) Javan rhinoceros Figure 55.3a–c

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 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 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 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 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 Case Study: The Greater Prairie Chicken and the Extinction Vortex Populations of the greater prairie chicken – Were fragmented by agriculture and later found to exhibit decreased fertility As a test of the extinction vortex hypothesis Scientists imported genetic variation by transplanting birds from larger populations

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The declining population rebounded – Confirming that it had been on its way down an extinction vortex EXPRIMENT Researchers observed that the population collapse of the greater prairie chicken was mirrored in a reduction in fertility, as measured by the hatching rate of eggs. Comparison of DNA samples from the Jasper County, Illinois, population with DNA from feathers in museum specimens showed that genetic variation had declined in the study population. In 1992, researchers began experimental translocations of prairie chickens from Minnesota, Kansas, and Nebraska in an attempt to increase genetic variation. RESULTS After translocation (blue arrow), the viability of eggs rapidly improved, and the population rebounded. CONCLUSION The researchers concluded that lack of genetic variation had started the Jasper County population of prairie chickens down the extinction vortex. Number of male birds (a) Population dynamics (b) Hatching rate Year Eggs hatched (%) Years Figure 55.10

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Minimum Viable Population Size The minimum viable population (MVP) – the minimum population size at which a species is able to sustain its numbers and survive A population viability analysis (PVA) Predicts a population’s chances for survival over a particular time Factors in the MVP of a population 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 Case Study: Analysis of Grizzly Bear Populations One of the first population viability analyses – Was conducted as part of a long-term study of grizzly bears in Yellowstone National Park Figure 55.11

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings This study has shown that the grizzly bear population – Has grown substantially in the past 20 years Number of individuals Females with cubs Cubs Year Figure 55.12

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 – 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 Case Study: Decline of the Red-Cockaded Woodpecker Red-cockaded woodpeckers – Require specific habitat factors for survival – Had been forced into decline by habitat destruction (a) A red-cockaded woodpecker perches at the entrance to its nest site in a longleaf pine. (b) Forest that can sustain red-cockaded woodpeckers has low undergrowth. (c) Forest that cannot sustain red-cockaded woodpeckers has high, dense undergrowth that impacts the woodpeckers’ access to feeding grounds. Figure 55.13a–c

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In a study where breeding cavities were constructed – New breeding groups formed only in these sites On the basis of this experiment – A combination of habitat maintenance and excavation of new breeding cavities has enabled a once-endangered species to rebound 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 One goal of landscape ecology, of which ecosystem management is part – Is to understand past, present, and future patterns of landscape use and to make biodiversity conservation part of land-use planning The structure of a landscape – Can strongly influence biodiversity

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 Corridors That Connect Habitat Fragments A movement corridor – Is a narrow strip of quality habitat connecting otherwise isolated patches – Promote dispersal and help sustain populations

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings In areas of heavy human use – Artificial corridors are sometimes constructed Figure 55.16

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Establishing Protected Areas Conservation biologists are applying their understanding of ecological dynamics – In establishing protected areas to slow the loss of biodiversity Much of the focus on establishing protected areas – Has been on hot spots of biological diversity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Finding Biodiversity Hot Spots A biodiversity hot spot is a relatively small area – With an exceptional concentration of endemic species and a large number of endangered and threatened species (GOOD FOR RESERVES) Terrestrial biodiversity hot spots Equator Figure 55.17

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Philosophy of Nature Reserves Nature reserves are biodiversity islands – In a sea of habitat degraded to varying degrees by human activity One argument for extensive reserves – Is that large, far-ranging animals with low- density populations require extensive habitats

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 Biotic boundary for short-term survival; MVP is 50 individuals. Biotic boundary for long-term survival; MVP is 500 individuals. Grand Teton National Park Wyoming Idaho 43  42  41  40  Kilometers Snake R. Yellowstone National Park Shoshone R. Montana Wyoming Montana Idaho Madison R. Gallatin R. Yellowstone R. Figure 55.18

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Zoned Reserves The zoned reserve model recognizes that conservation efforts – Often involve working in landscapes that are largely human dominated

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Zoned reserves – Are often established as “conservation areas” The zoned reserve model recognizes that conservation efforts – Often involve working in landscapes that are largely human dominated (a) Boundaries of the zoned reserves are indicated by black outlines. (b) Local schoolchildren marvel at the diversity of life in one of Costa Rica’s reserves. Nicaragua Costa Rica Panama National park land Buffer zone PACIFIC OCEAN CARIBBEAN SEA Figure 55.19a, b

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Some zoned reserves in the Fiji islands are closed to fishing – Which actually helps to improve fishing success in nearby areas Figure 55.20

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Whether a disturbance is natural or caused by humans – Seems to make little difference in this size- time relationship Recovery time (years) (log scale) ,  3 10  2 10  , Natural disasters Human-caused disasters Natural OR human- caused disasters Meteor strike Groundwater exploitation Industrial pollution Urbanization Salination Modern agriculture Flood Volcanic eruption Acid rain Forest fire Nuclear bomb Tsunami Oil spill Slash & burn Land- slide Tree fall Lightning strike Spatial scale (km 2 ) (log scale) Figure 55.21

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings One of the basic assumptions of restoration ecology – Is that most environmental damage is reversible Two key strategies in restoration ecology – Are bioremediation and augmentation of ecosystem processes Bioremediation – use of living organisms to detoxify ecosystems 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

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Case Study: Sustainable Development in Costa Rica Costa Rica’s 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 Infant mortality (per 1,000 live births) Year Life expectancy Infant mortality Life expectancy (years) Figure 55.23

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 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 (a) Detail of animals in a Paleolithic mural, Lascaux, France Figure 55.24a

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 (b) Biologist Carlos Rivera Gonzales examining a tiny tree frog in Peru Figure 55.24b