Biodiversity and Conservation. Levels of Biodiversity. Humans are reducing Earth ’ s diversity of life Biodiversity – sum total of all organisms in an area Split into three specific levels: Species diversity Genetic diversity Ecosystem diversity. Species Diversity.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Levels of Biodiversity • Humans are reducing Earth’s diversity of life • Biodiversity – sum total of all organisms in an area • Split into three specific levels: • Species diversity • Genetic diversity • Ecosystem diversity
Species Diversity • Species Diversity = the number or variety of species in the world or in a particular region • Richness = the number of species • Evenness or relative abundance = extent to which numbers of individuals of different species are equal or skewed • Speciation generates new species and adds to species richness • Extinction reduces species richness
Taxonomy Taxonomists = scientists who classify species Physical appearance and genetics determines a species Genera = related species are grouped together Families = groups of genera Every species has a two-part scientific name: genus and species
Siberian tiger = Panthera tigris altaica Subspecies • Subspecies = populations of species that occur in different areas and differ slightly from each other • Divergence stops short of separating the species • Subspecies are denoted with a third part of the scientific name Bengal tiger = Panthera tigris tigris
Genetic Diversity • Encompasses the differences in DNA among individuals within species and populations • The raw material for adaptation to local conditions • Populations with higher genetic diversity can survive • They can cope with environmental change • Populations with low genetic diversity are vulnerable • To environmental change • Disease • Inbreeding depression = genetically similar parents mate and produce inferior offspring
Conservation at the Species Level • Species approach • Focus is on helping individual species that is threatened and action is taken directly to the species • Example: introducing 3 male penguins into an unrelated population of penguins whose gene pool isn't varied enough • Sanctuaries • Gene banks, botanical gardens farms raise threatened species can help prevent extinction. • Zoos and aquariums can help protect endangered animal species by preserving some individuals with the long-term goal of reintroduction.
Reconciliation • Reconciliation ecology involves finding ways to share places we dominate with other species. • Replacing monoculture grasses with native species. • Maintaining habitats for insect eating bats can keep down unwanted insects. • Reduction and elimination of pesticides to protect non-target organisms (such as vital insect pollinators).
Ecosystem Diversity • Ecosystem diversity = the number and variety of ecosystems • Also encompasses differing communities and habitats • Rapid vegetation change and varying landscapes within an ecosystem promote higher levels of biodiversity
Ecosystem Diversity • Species are not evenly distributed among taxonomic groups • Insects predominate over all other life-forms • 40% of all insects are beetles • Groups accumulate species by • Adaptive radiation • Allopatric speciation (species isolation) • Low rates of extinction • Review Evolution • Microevolution, macroevolution, natural selection, artificial selection, fitness, adaptation, niche, mutation, sympatric vs. allopatric speciation, bottleneck, founder effects.
Ecosystem Conservation • Ecosystem approach • take direct action on the environment to help a species (or several) • Example: Controlling mammalian pests in a reserve to help give the threatened species a chance to thrive
Ecosystem Approach • Establish National Parks • Countries have established more than 1,100 national parks, but most are threatened by human activities. • Local people invade park for wood, cropland, and other natural resources. • Loggers, miners, and wildlife poachers also deplete natural resources. • Many are too small to sustain large-animal species. • Many suffer from invasive species.
National Park vs. National Forest • National parks emphasize strict preservation of pristine areas. The ultimate goal is to preserve resources "unimpaired for future generations." Park rangers work for the National Park Service (NPS) under the Department of the Interior. • National forests, emphasize not only resource preservation, but other kinds of use as well. Under this concept of "multiple use", national forests are managed to provide Americans with lumber, cattle grazing, mineral products and recreation with and without vehicles. The national forests are managed by forest rangers with the US Forest Service (USFS) under the Department of Agriculture.
Ecology Conservation: Reserves • Ecologists call for protecting more land to help sustain biodiversity, but powerful economic and political interests oppose doing this. • Currently 12% of earth’s land area is protected. • Only 5% is strictly protected from harmful human activities. • Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes.
Reserves • Large and medium-sized reserves with buffer zones help protect biodiversity and can be connected by corridors. • Costa Rica has consolidated its parks and reserves into 8 mega reserves designed to sustain 80% of its biodiversity.
A model biosphere reserve that contains a protected inner core surrounded by two buffer zones that people can use for multiple use.
Restoration • Five basic science-based principles for ecological restoration: • Identify cause. • Stop abuse by eliminating or sharply reducing factors. • Reintroduce species if necessary. • Protect area form further degradation. • Use adaptive management to monitor efforts, assess successes, and modify strategies.
Measuring Biodiversity • Out of the estimated 3 - 100 million species on Earth, only 1.7 - 2 million species have been successfully catalogued • Very difficult to identify species • Many remote spots on Earth remain unexplored • Small organisms are easily overlooked • Many species look identical until thoroughly examined • Entomologist Terry Erwin found 163 beetle species specialized on one tree species • Refer to lab and Simpson’s Index
Biodiversity is not evenly distributed • Living things are distributed unevenly across Earth • Latitudinal gradient = species richness increases towards the equator • Canada has 30 - 100 species of breeding birds, while Costa Rica has more than 600 species
Loss of Species • Extinction = occurs when the last member of a species dies and the species ceases to exist • Extirpation = the disappearance of a particular population from a given area, but not the entire species globally • Can lead to extinction • Extinction is a natural process • Paleontologists estimate 99% of all species that ever lived are now extinct • Background rate of extinction = natural extinctions for a variety of reasons • 1 extinction per 1 to 10 million species for mammals and marine species • 1 species out of 1,000 mammal and marine species would go extinct every 1,000 to 10,000 years
Endangered and Extinct Species Could become extinct soon. Population declining very fast. Endangered and Threatened Species Threatened Endangered Spectacled Bear
Endangered and Extinct Species • Characteristics of Endangered Species • Extremely small range • Requiring large territories • Living on islands • Low reproductive success • Specialized breeding areas • Specialized feeding habits Tiburon mariposa lily California condor Hawaii ‘O’ o Blue whale Green sea turtle Giant panda
Endangered and Extinct Species • Most Impacted areas • Hawaii and other island habitats • Tropical rain forests • http://www.pbs.org/wnet/nature/episodes/the-dragon-chronicles/video-komodo-dragon-chases-rom/4520/
Past Mass Extinctions • In the past 440 million years, mass extinctions have eliminated at least 50% of all species • After every mass extinction the biodiversity returned to or exceeded its original state
Current Mass Extinction is Human Caused • During this Quaternary period, we may lose more than half of all species • Hundreds of human-induced species extinctions, and multitudes of others, teeter on the brink of extinction • The current global extinction rate is 100 to 1,000 times greater than the background rate • This rate will increase tenfold in future decades due to human population growth and resource consumption
Loss of Biodiversity is more than extinction • Decreasing numbers are accompanied by smaller species’ geographic ranges • Genetic, ecosystem, and species diversity are being lost. • The Living Planet Index summarizes trends in populations • Between 1970 and 2003, the Index fell by 30%
Causes of Biodiversity Loss • Reasons for biodiversity losses are multifaceted, complex, and hard to determine • Factors may interact synergistically • Four primary causes of population decline are: • Habitat alteration • Invasive species • Pollution • Overharvesting • Global climate change now is the fifth cause
Habitat Loss • The greatest cause of biodiversity loss • Farming simplifies communities • Grazing modifies the grassland structure and species composition • Clearing forests removes resources organisms need • Hydroelectric dams turn rivers into reservoirs upstream • Urbanization and suburban sprawl reduce natural communities • A few species (i.e., pigeons, rats) benefit from changing habitats
Invasive Species • Introduction of non-native species to new environments • Accidental: zebra mussels • Deliberate: food crops • Island species are especially vulnerable • Invaders have no natural predators, competitors, or parasites • Cost billions of dollars in economic damage
Pollution • Harms organisms in many ways • Air pollution degrades forest ecosystems • Water pollution adversely affects fish and amphibians • Agricultural runoff harms terrestrial and aquatic species • The effects of oil and chemical spills on wildlife are dramatic and well known • The damage to wildlife and ecosystems caused by pollution can be severe • But it tends to be less than the damage caused by habitat alteration or invasive species
Overharvesting • Vulnerable species are large, few in number, long-lived, and have few young (K-selected species) • The Siberian tiger is hunted without rules and regulations • The early 1990s saw increased poaching because of powerful economic incentives • Many other species affected: Atlantic gray whale, sharks, gorillas Today the oceans contain only 10% of the large animals they once did
Climate Change • Emissions of greenhouse gases warms temperatures • Modifies global weather patterns and increases the frequency of extreme weather events • Increases stress on populations and forces organisms to shift their geographic ranges • Most animals and plants will not be able to cope
Biodiversity is good for ecosystems (ecosystem services) • Provides food, shelter, fuel • Purifies air and water, and detoxifies wastes • Stabilizes climate, moderates floods, droughts, wind, temperature • Generates and renews soil fertility and cycles nutrients • Pollinates plants and controls pests and disease • Maintains genetic resources • Provides cultural and aesthetic benefits • Allows us to adapt to change
Biodiversity Loss in an Ecosystem • Biodiversity increases the stability and resilience of communities and ecosystems • Decreased biodiversity reduces a natural systems ability to function and provide services to our society • The loss of a species affects ecosystems differently • If the species can be functionally replaced by others, it may make little difference • Extinction of a keystone species may cause other species to decline or disappear • “To keep every cog and wheel is the first precaution of intelligent tinkering” (Aldo Leopold)
Biodiversity affects food security • Genetic diversity within crops is enormously valuable • Turkey’s wheat crops received $50 billion worth of disease resistance from wild wheat • Wild strains provide disease resistance and have the ability to grow back year after year without being replanted
Biodiversity and Medicines • Each year pharmaceutical products owing their origin to wild species generate up to $150 billion in sales • The rosy periwinkle produces compounds that treat Hodgkin's disease and leukemia
Some economic benefits of biodiversity • People like to experience protected natural areas, creating economic opportunities for residents, particularly in developing countries • Costa Rica: rainforests (Excellent at ecotourism) • Australia: Great Barrier Reef • Belize: reefs, caves, and rainforests • A powerful incentive to preserve natural areas and reduce impacts on the landscape and on native species • But, too many visitors to natural areas can degrade the outdoor experience and disturb wildlife
People Value and seek nature • Biophilia = connections that humans subconsciously seek with life • Our affinity for parks and wildlife • Keeping of pets • High value of real estate with views of natural lands • Nature deficit disorder = alienation from the natural environment • May be behind the emotional and physical problems of the young
Conservation Biology • Conservation biology = devoted to understanding the factors that influence the loss, protection, and restoration of biodiversity • Arose as scientists became alarmed at the degradation of natural systems • An applied and goal-oriented science
Conservation Biology • Conservation biologists integrate evolution and extinction with ecology and environmental systems • Design, test, and implement ways to mitigate human impacts • Conservation geneticists = study genetic attributes of organisms to infer the status of their population • Minimum viable population = how small a population can become before it runs into problems • Metapopulations = a network of subpopulations • Small populations are most vulnerable to extinction and need special attention
Should we focus on endangered species? • Endangered Species Act (1973) (ESA) = forbids the government and private citizens from taking actions that destroy endangered species or their habitats-40 Year anniversary! • To prevent extinction • Stabilize declining populations • Enable populations to recover • US has approximately 2050 endangered species. • http://www.fws.gov/endangered/ • http://www.nmfs.noaa.gov/pr/laws/esa/
ESA • Through federal action and by encouraging the establishment of state programs, the 1973 Endangered Species Act provided for the conservation of ecosystems upon which threatened and endangered species of fish, wildlife, and plants depend. The Act: • authorizes the determination and listing of species as endangered and threatened; • prohibits unauthorized taking, possession, sale, and transport of endangered species; • provides authority to acquire land for the conservation of listed species, using land and water conservation funds; • authorizes establishment of cooperative agreements and grants-in-aid to States that establish and maintain active and adequate programs for endangered and threatened wildlife and plants; • authorizes the assessment of civil and criminal penalties for violating the Act or regulations; and • authorizes the payment of rewards to anyone furnishing information leading to arrest and conviction for any violation of the Act or any regulation issued thereunder.
Amendments to ESA • Habitat Conservation Plans • 1982 amendment to ESA • Landowner allowed to set aside land for endangered species, but develop other land with those species
Successes • Peregrine falcons, brown pelicans, bald eagles, and others have recovered and are no longer listed • Intensive management has stabilized other species • The red-cockaded woodpecker • 40% of declining populations are now stable • These successes occur despite underfunding of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service • In recent years, political forces have attempted to weaken the ESA • http://www.pbs.org/wnet/nature/episodes/american-eagle/video-full-episode/4349/
Ways to preserve biodiversity • Captive breeding – individuals are bred and raised with the intent of reintroducing them into the wild • Zoos and botanical gardens • Some reintroductions are controversial • Ranchers opposed the reintroduction of wolves to Yellowstone National Park • Some habitat is so fragmented, a species cannot survive • Seed Banks