Lecture 22 - Conservation Biology.pptx.pdf

Conservation Biology Concepts 56.1-56.5 Campbell. Biology. 3rd ed. Outline • 1. Human activities affect Earth's biodiversity • 2. Conservation sustains biodiversity • 3. Global changes and human actions • 4. Sustainable development 1. Human activities affect Earth's biodiversity • Extinction is...

Conservation Biology Concepts 56.1-56.5 Campbell. Biology. 3rd ed. Outline • 1. Human activities affect Earth's biodiversity • 2. Conservation sustains biodiversity • 3. Global changes and human actions • 4. Sustainable development 1. Human activities affect Earth's biodiversity • Extinction is a natural phenomenon, however, the current extinction rate is higher today than ever before and responsible for the biodiversity crisis on Earth • Human activities are a major threat to extinction and loss of biodiversity • 3 levels of biodiversity • Genetic diversity • Species diversity • Ecosystem diversity Genetic Diversity • Genetic Diversity = includes individual genetic variation within a population and between populations • Associated with adaptations to local conditions • Extinction of one population causes an entire species to lose genetic diversity • Reduction in genetic diversity reduces adaptive potential of the species Species Diversity • Species diversity = the variety of species in an ecosystem or across the biosphere • Species diversity decreases with extinction rates • Extirpation = local extinction • Global extinction = species lost from all ecosystems • International Union for Conservation of Nature and Natural Resources (IUCN) states the following are threatened or near extinction • 12% of the 10,000 known bird species • 21% of the 5,500 known mammals Hundred Heartbeats Club • Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is a panel of Canadian scientists who assess conservation status and make recommendations to federal government • Quantitative criteria • Declining abundance, limited distribution, small population size • Qualitative criteria • Threats, life history traits • Extinct species are gone; endangered species are nearing extinction; threatened species likely to become endangered if no action taken • Federal gov. Decides which species will receive protection under Species at Risk Act (SARA) • Eg Beluga whale population in Hudson's Bay • Eg. Swift fox Species at Risk in Canada Ecosystem Diversity • Ecosystem = all the organisms in a given area along with the abiotic and biotic factors they interact with • IUCN criteria for assessing ecosystem status • Red List for ecosystems threatened by human activity • • • • Collapsed (equivalent to extinct for species) Critically endangered Endangered Vulnerable • Goal is to identify which ecosystems are most at risk of species loss or ecological functions or services • Data includes decline in distribution, level of degradation, disruption of biotic processess or interaction Species and Genetic Diversity Benefits • Food, fibre, medicine, esthetics • Eg. Rosy Periwinkle inhibits cancer • Eg. Prokaryotes proteins • Wild plants become cultivated plants and/or contribute genetic resources to crop quality Svalbard Global Seed Vault Photo credit JUNGE, HEIKO/AFP via Getty Images Ecosystem Services • Ecosystem services = all the process through which natural ecosystems help sustain human life • clean air, filter water, bacteria/fungi decompose wastes, insect pollinators, tree roots prevent erosion • Evidence suggests that functioning of ecosystems and their services are linked to increased biodiversity • Reductions in biodiversity through human activities are reducing ecosystem functions and services which are necessary to the growth and survival of all organisms, including humans Threats to Biodiversity • Habitat Loss • Single greatest threat to biodiversity • Causes include agriculture, urban development, forestry, mining and pollution • Global climate change will continue to effect habitat loss into this century • Habitat loss leads to extinction • IUCN states destruction of physical habitat accounts for 73% of all extinctions, endangered and vulnerable classifications of species • 98% of tropical dry forests in central America and Mexico have been cut • Agriculture responsible for majority of habitat loss in Canada • Eg. Logging and oil sands in Alberta and woodland Caribou Conversion of forests to agriculture is one of the leading causes of habitat loss worldwide • Introduced Species • Nonnative or exotic • Species that human move intentionally or accidentally • Disrupt new community: predators, parasites, pathogens • Eg. Brown tree snakes in Guam • Eg. Parastic sea lamprey in Lake Ontario • Eg. Zebra muscles in Great Lakes • Majority of extinctions due to introduced species occur on islands and are due to introduced predators • Eg. Rats and feral cats in Hawaii • Overharvesting • Humans harvesting wild organisms at rates that exceed their ability to rebound • Species with restricted habitats (eg islands) are especially vulnerable • Eg. Great Auk on islands in North Atlantic • Animals with low reproductive rates • Eg. Elephants, whales and rhinoceros (northern white rhino. No males remain) Figure 56.9 Decline and Partial Recovery of Elephant Populations in Tsavo National Park in Kenya • Global Change • Alterations in broad ecological systems and atmospheric chemistry, climate and ozone depletion 2. Conservation sustains biodiversity • Historical efforts focused on species. Today focus is on sustaining biodiversity of communities, ecosystems and landscape ecology • Landscape ecology goals include projecting future patterns of landscape use and inclusion of biodiversity conservation as part of land-use planning Landscape Structure and Biodiversity Edges and Fragmentation • Edges are boundaries between ecosystems • Between a bog and surrounding area • Between a patch of forest and a burned area • Some organisms thrive in edges because resources can be captured from adjacent areas • Eg white tailed deer • Human created edges have reduced biodiversity and dominance of edge adpated species. Some edge adapted species are problematic • Eg, Brown headed cowbirds affect migratory songbirds • • Corridors Connect Fragmented Habitats • Movement corridors are narrow strips or series of small clumps of habitat that connect isolated patches • Riparian (transitional area between an upland dry area and a water body) habitats often serve as corridors • Some government policies include corridors in areas of heavy human use, artifical corridors are created • Eg Trans Canada highway near Banff Establishing Protected Areas • Protected areas slow down biodiversity loss • 7% of worlds land has been established into natural reserves • Canada has 10% land area in reserve • Areas of preservation include • Biodivesity Hotspots • Nature Reserves • Zoned Reserves Hot Spot is a relatively small area with numerous endemic species • Reserves • Protected areas within human altered or degraded areas • Zoned Reserve = an extensive region that includes areas relatively undisturbed by humans surrounded by areas that have been changed by human activity and are used for economic gain • Surrounding areas support human acitivites but regulate and prevent extensive alterations of the protected area • Become buffer zones • Costa Rica relies on zoned reserves to maintain >80% of its native species • Buffer zones serve to provide forest products, water and hydroelectric power, agriculture and tourism • Canada is establishing network of reserves for marine ecosystems • Endeavour Thermal Vents and thermophiles west of Vancouver Island • Preservation of 9,000 year old Glass Sponge Reef Zoned Reserves in Costa Rica • Urban Ecology • Examines organisms and their environment in urban settings • Critical areas of research include urban streams and the quality and flow of their water as well as organisms found within them 3. Global changes and human actions • Global changes include climate, atmospheric chemistry and broad ecological systems that may reduce the ability of Earth to sustain life • 5 large scale environmental changes brought about by humans • Acid precipitation • Nutrient Enrichment • Toxins in the Environment • Greenhouse Gases and Climate Change • Ozone Depletion Acid Precipitation • Rain, snow, sleet, fog with pH less than 5.2 • Burning wood and fossil fuels release sulfur and nitrogen into the atmosphere that react with water vapor to form sulphuric and nitric acids • When this precipation falls to Earth, it harms some aquatic and terrestrial environments • Eg. Clearwater Lake near Sudbury, Ontario • Eg. Nova Scotia, Salmon population were extirpated from 14 rivers with ph less than 4.7 Nutrient Enrichment • Agriculture effects movement and storage of nutrients in terrestrial ecosystems • Crop uptake, nutrients lost from land clearing, crop harvest, erosion • Inorganic nitrogen fertilizer rates have doubled amount of nitrogen entering terrestrial ecosystems on a global scale • Nearly 1/3 of nitrogen entering is lost from the system • Burning fossil fuels contributes to nitric acid precipitation • Critical load = the amount of added nutrient, usually nitrogen or phosphorus, that can be absorbed by plants without damaging ecosystem integrity • Excess leach into groundwater, cause contamination of water supplies and fish kills. Some levels are unsafe for drinking • Eutrophication of lakes Figure 56.23 Phytoplankton bloom arising from nitrogen pollution in the Mississippi basin that leads to a dead zone Toxins in the Environment • Organisms acquire toxic substances from the environment • Some are excreted or metabolized • Some accumulate in specific tissues, namely fat • Bioaccumulation = accumulation over time of a substance, usually a contaminant, in a living organisms • Biomagnification = is the process by which toxic chemicals build up within predators • DDT and Rachel Carson ”The book that birthed modern environmentalism” “This book was a shaft of light that for the first time illuminated what is arguably the most important issue of our era.” - Al Gore Courtesy of Alex Bashair & Matthew Showna Historical perspectives • 1962: Silent Spring • 1969: National Environmental Policy Act (requiring Enviro Impact Statements) • 1970: Creation of EPA (Environmental Protection Agency; established on December 2, 1970) • 1970: Clean Air Act (to control air pollution in national level) • 1972: Clean Water Act • 1972: U.S. bans DDT • 1973: Endangered Species Act Rachel Carson (1907-1964) Greenhouse Gases and Climate Change • Carbon Dioxide Levels • Increasing levels are expected to increase plant productivity • Eg. Greenhouse experiments – plants grow faster with elevated CO2 levels • Eg. Forestry plots produced 15% more wood • Creation of a warmer planet • Greenhouse gases reflect solar radiation back to Earth • Average global temperatures will rise 1-4C if CO2 levels double as models predict • Ecosystems will move and change • Boundaries of ecosystems will expand toward the poles • Grasslands will expand north and replace forest • Plants and animals will migrate north • Some habitats will disappear • Crops and cropland • Greenhouse gas emissions • Fossil fuel burning, deforestation, methane from ruminants in agriculture, landfills • Insect Pests and Disease may be more Common • for many insect and microbe populations, growth rates increase with temperatures • Solutions • reduce burning of coal, natural gas, wood • Use of more efficient systems including solar energy, wind power and nuclear power • Future = capture and bury CO2 emissions? • Reduce methane emission. Careful management of manures and livestock. Reduce consumption of ruminant livestock? • Aeration of rice paddies • Emissions from landfills can be captured and used as fuel Depletion of Atmospheric Ozone • Ozone (O3) has also changed due to human activities • Destruction of ozone mainly caused from accumulation of chloroflurocarbons (CFCs) chemicals previously used in refrigeration and manufacturing • Chlorine atoms released from CFCs react with ozone and reduce it to O2 • Most apparent over Antarctica in Spring • Leads to intensity of UV rays reaching Earth • Skin cancer, cataracts in humans, effects on crops, phytoplankton • 1987 Montreal Protocol = 190 nations = treaty that regulates the use of ozone depleting chemicals • Most nations have ended CFCs 4. Sustainable development The Three Pillars of Sustainability https://www.entrepreneur.com/article /252029 • Sustainable development = economic development that meets the needs of people today without limiting the ability of future generations to meet their needs • Connect natural science, social science, economics and humanities • Reasses our personal values Final Words "Biology is the scientific expression of our desire to know nature. We are most likely to protect what we appreciate, and we are most likely to appreciate what we understand. By learning about the processes and diversity of life, we also become more aware of ourselves and our place in the biosphere." Campbell. Biology. 3rd ed.