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GEOG 101: Day 10 Biodiversity and Conservation Biology
Housekeeping Items • I will collect your outlines • Any thoughts about the field trip? • A number of communities in BC have passed resolutions banning GM foods. These are largely symbolic, but one food activist in Vancouver would like to go further. • Worldbridger is showing the Clean Bin Project tonight at 7 p.m. in 356, Room 109. • If you want a chance to influence the timing of Solutions meetings, go to http://doodle.com/bxcpxxin6t8fk43m • We didn’t get a chance to talk about the “slow food” movement. On the theme of food, here’s a funny cartoon: www.cartoonistgroup.com/store/add.php?iid=115522.
Housekeeping Items • Community events for October 2 - October 5: • All week: My Green VIU • hosted by VIU Environment and Sustainability, a contest to demonstrate how you conserve energy on campus. Check it out here: http://sites.viu.ca/sustainability/sustainability-2014/1368-2 • Oct 2 - 4 Zero Waste Conference • Learn more here: http://www.zerowastecanada.ca/zero-waste-canada-conference-zwia14 • We didn’t get a chance to talk about the “slow food” movement. On the theme of food, here’s a funny cartoon: www.cartoonistgroup.com/store/add.php?iid=115522.
Housekeeping Items • You are also invited to the Virtual Classroom with David Suzuki and Friends next Monday, October 6 from 8:30-10 am in the Royal Arbutus Room above the upper cafeteria. This is a FREE event, but due to limited space please indicate your interest to firstname.lastname@example.org • The event is described as follows: • VIU is taking part in the Hungry for Change conversation event being put on by the National Film Board, David Suzuki Foundation and Humber College. The discussion is around the intersection of food and environmental justice. • David Suzuki, food justice expert Utcha Sawyers and J.B. MacKinnon, author of The Once and Future World and co-author of The 100-Mile Diet, will lead the conversation about the impacts of modern food systems and farming practices on our health, land and food security. The event will also feature a special performance by poet Tanya Davis. • For more details please see the following event link: http://sites.viu.ca/sustainability/hungry-for-change-a-canada-wide-conversation
News / Canada Researcher warns of looming 'catastrophe' for St. Lawrence beluga population The latest figures come amid a debate over whether to allow exploratory drilling off shore of Cacouna, Que., near the breeding ground at the mouth of the St. Lawrence. October 1st, Toronto Star
JACQUES BOISSINOT / THE CANADIAN PRESS • By: Benjamin Shingler The Canadian Press, Published on Sun Sep 28 2014 • MONTREAL—A researcher monitoring belugas in the St. Lawrence estuary is warning of a looming "catastrophe" after another difficult calving season for the endangered whale. • The belugas have been in a slow population decline for the past decade, according to Robert Michaud, the scientific director of Quebec's Marine Mammals Research and Education Group. • His team has found the carcasses of at least five baby belugas so far during the calving period, which officially ends on Oct. 15. The number of dead beluga calves turning up on the shore has been unusually high since 2008, Michaud said. • "It's a catastrophic trajectory we're observing, and we don't yet know exactly what are the causes for that," he said. • "The only way this population can reverse its trajectory would be to increase the survival rate and the birth rate, and what we've been observing for the last years is totally the opposite….
Upon successfully completing this chapter, you will be able to • Characterize the scope and value of biodiversity on Earth • Describe ways to measure biodiversity • Evaluate the primary causes of biodiversity loss • Specify the benefits and challenges of conserving habitat and the role of habitat fragmentation • Contrast in situ and ex situ conservation approaches • Compare and contrast traditional and innovative conservation efforts • Outline reasons for setting aside parks, reserves, and other protected areas
Central Case: Saving the Polar Bear: What Will it Take? • “There will be no polar ice by 2060. Somewhere along that path, the polar bear drops out.” • Committee on the Status of Endangered Wildlife in Canada (COSEWIC) – for political reasons the polar bear was not be listed as a “threatened” species, though in the U.S. they are • Polar bears are coming into contact and interbreeding with other types of bears • Polar bears are appearing more frequently in human settlements • Traditional Inuit hunting practices are being affected by the loss of sea ice, a process for which they are not responsible • What will it take to save the polar bear? 9-9
Our Planet of Life 9-10
Biodiversity encompasses several levels • Biodiversity = sum total of all organisms in an area at whatever scale, including • Ecosystem diversity • Species diversity • Genetic diversity
Biodiversity encompasses several levels (cont’d) • Species Diversity = the number or variety of species in the world or in a particular region • Species 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
Biodiversity encompasses several levels (cont’d) • Species Diversity • Immigration is the inmigration of a species to an area • Emigration is the outmigration of a species from an area • Extirpation is the local extinction of a species
Biodiversity encompasses several levels (cont’d) • Genetic Diversity • All species consist of individuals that vary genetically from one another to some degree (this is as much true for humans as it is for other species) • Encompasses the varieties in DNA among individuals within species and populations • The raw material for adaptation to local conditions, though some species can adapt much more quickly (such as the peppered moth)
Biodiversity encompasses several levels (cont’d) • Genetic Diversity • Populations with low genetic diversity are vulnerable • Inbreeding depression = genetically similar parents mate and produce inferior offspring (e.g. certain offspring of overly inbred royal families or of hillbillies) • Genetic bottleneck = limited variety of genetic material is available to be passed along by the small number of surviving individuals to their descendants
Biodiversity encompasses several levels (cont’d) • 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 • Ecotones = where different types of habitats or biomes intermix
Some groups hold more species than others • Insects predominate over all other life-forms – hence a lack of ‘evenness’ • 40% of all insects are beetles (yeah, yeah, yeah!) • Groups accumulate species by • Adaptive radiation • Allopatric speciation (from isolation) • Low rates of extinction
Mammals= 2.7-03% Insects outnumber all other species
Measuring biodiversity is not easy • Precise quantitative measurements are difficult • About 1.8 million species but likely higher • Incomplete for several reasons • Some areas of Earth little explored (new species being discovered all the time in Australia) • Many species are tiny and overlooked • Many organisms are difficult to identify 9-20
Biodiversity is unevenly distributed on the planet • Latitudinal gradient = species richness increases towards the equator • Plant productivity and climate stability play key roles
Biodiversity loss and species extinction • Canadian Species at Risk Act usescategorizes: • 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 • Endangered = species in imminent danger of becoming extirpated or extinct • Threatened = species likely to become endangered in the near future
Extinction and extirpation occur naturally • Paleontologists estimate that 99% of all species that ever lived are now extinct • Background rate of extinction = natural extinctions for a variety of reasons • 1 species out of 1,000 mammal and marine species would normally go extinct every 1,000 to 10,000 years • or 1 in a 1000 would typically go extinct every year
Extinction and extirpation occur naturally (cont’d) • Earth has experienced five previous mass extinction episodes • In the past 440 million years, mass extinctions have eliminated at least 50% of all species • Today’s mass extinction is caused by humans and humans will suffer as a result of it
Some species are more vulnerable to extinction than others • In general, extinction occurs when environmental conditions change so severely that a species cannot adapt to the change. What kinds of changes are occurring today that fall into this category? • … • … • Vulnerable = species that are of particular concern because of characteristics that make them particularly sensitive to human activities or natural events. What are some species we can consider ‘vulnerable,’ and due to what? • …. • …. 9-27
Humans have started the sixth mass extinction Extinctions followed human arrival on islands and continents
Humans have started the sixth mass extinction (cont’d) • Global extinction rate is currently 100 to 1000 times greater than background rate • The Red List = an updated list of species facing high risks of extinctions – at least • 23% of mammal species • 12% of bird species • 17% to 75% of all other species • Extinction is only part of the story of biodiversity loss, the larger part of the story is decline in population sizes
Humans have started the sixth mass extinction (cont’d) • The Living Planet Index quantifies biological degradation • Between 1970 and 2007, the Index fell by 30%
There are several major causes of biodiversity loss • Reasons for biodiversity losses are multifaceted and factors may interact synergistically • Causes of population decline: • Habitat alteration • Invasive species • Pollution, including pesticides • Overharvesting • Climate change
There are several major causes of biodiversity loss (cont’d) • Habitat alteration • The greatest cause of biodiversity loss • E.g., 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
There are several major causes of biodiversity loss (cont’d) • 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 • What are some West Coast invasives?
Several major causes of biodiversity loss (cont’d) • 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
Several major causes of biodiversity loss (cont’d) • Overharvesting • Vulnerable species are large, few in number, long-lived, and have few young (K-selected species) • The Siberian tiger (The 1989 political freedom in Soviet Union brought the freedom to hunt and poach) • Atlantic gray whale has gone extinct • Thousands of sharks killed just for fins • Gorillas killed for their meat
Several major causes of biodiversity loss (cont’d) • Climate change • Global impact on habitat and biodiversity • Greenhouse gases 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
Over 2500 amphibian species worldwide are in decline • Some may be lost before they are even discovered • Amphibians are regarded as “biological indicators” (‘canary in the coalmine’ analogy) • Habitat loss, especially draining of wetlands, is the leading threat to amphibians in Canada • Pollution, fragmentation are also problems 9-42
FREE!! Biodiversity provides ecosystem services • Provides food, fuel, and fibre • Provides shelter and building materials • Purifies air and water • Detoxifies and decomposes wastes • Stabilizes and moderates Earth’s climate • Moderates floods, droughts, wind, and temperature extremes • Generates and renews soil fertility and cycles nutrients • Pollinates plants, including many crops • Controls pests and diseases • Maintains genetic resources as inputs to crop varieties, livestock breeds, and medicines • Provides cultural and aesthetic benefits • Gives us the means to adapt to change The annual value of just 17 ecosystem services = $16 to 54 trillion per year
Biodiversity helps maintain ecosystem integrity • Biodiversity increases the stability and resilience of communities and ecosystems (like rivets in airplane) • Decreased biodiversity reduces a natural system’s 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 • Precautionary principle: “To keep every cog and wheel is the first precaution of intelligent tinkering” (Aldo Leopold)
Biodiversity enhances food security • Genetic diversity within crops is enormously valuable • California’s barley crops annually receive $160 million in disease resistance benefits from Ethiopian strains of barley • Wild strains provide disease resistance and have the ability to grow back year after year without being replanted • New potential food crops are waiting to be used • Serendipity berry produces a sweetener 3,000 times sweeter than sugar
Biodiversity provides drugs and medicines • Each year pharmaceutical products owing their origin to wild species generate up to $150 billion in sales
How Best to Conserve Biodiversity? weighingtheissues Most people view national parks and ecotourism as excellent ways to help keep ecological systems intact. Yet the golden toad went extinct despite living within a reserve established to protect it. Moreover, climate change does not pay attention to park boundaries. What lesson can we learn from this about the conservation of biodiversity?
Biodiversity provides additional economic benefits • Ecotourism is particularly beneficial in developing and developed countries alike • Costa Rica: rainforests • Australia: Great Barrier Reef • Belize: reefs, caves, and rainforests • Incentive to preserve natural areas and reduce impacts on the landscape and on native species • However, too many visitors can degrade the outdoor experience and disturb wildlife
People value and seek out connections with 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 some of the emotional and physical problems of the young See “Biophilic Design” in the VIU Library