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Biodiversity: Who cares? Which do you like better? A B Which do you like better? A B Which do you like better? A B Which do you like better? A B Which do you like better? A B Which do you like better? A B Which do you like better? A B What do you think biodiversity means? Biodiversity What does “Bio” mean? Bio = Biodiversity What does “Diversity” mean? Diversity = Variety Biodiversity is the variety of life on Earth • Scientists have identified more than 2 million species. Tens of millions -- remain unknown •The tremendous variety of life on Earth is made possible by complex interactions among all living things including microscopic species like algae and mites. MUTUALISM There are 3 components of biodiversity 1. Diversity of genes Chihuahuas, beagles, and rottweilers are all dogs— but they're not the same because their genes are different. Chihuahua Beagle Rottweilers There are 3 components of biodiversity Diversity of species For example, monkeys, dragonflies, and meadow beauties are all different species. Saki Monkey Golden Skimmer Meadow Beauty There are 3 components of biodiversity Variety of ecosystems Prairies, Ponds, and tropical rain forests are all ecosystems. Each one is different, with its own set of species living in it. Paines Prairie Florida Sand hill Pond Hoh Rain Forest Which is more diverse? A B Which is more diverse? A B Which is more diverse? A B Which is more diverse? A B Which has more cultural diversity? A B Which has more biodiversity? A B Which has more biodiversity? A B Biodiversity has Value 1. Aesthetic reasons Would you rather live in a world with or without clear mountain streams, grizzly bears, and orchids? 2. Ethical reasons Do we have the right to drive other species to extinction? Do we have the right to leave the world in worse shape for our children and grandchildren than it was in when we were born? 3. Medicines Would we be better off without penicillin and other pharmaceuticals derived from nature? Would will be better off without future discoveries of organisms that will provide useful drugs and medicines? 4. Economic reasons Would we be better off without the estimated $33 trillion in ecosystem services provided by the whole-earth ecosystem? Example: soil formation, nutrient cycling, food production and much more 5. Recreation Americans spend $104 billion ever year on wildlife related recreation (we spend $81 billion dollars each year on new automobiles) Would we be better off without commercial and sport fisheries? Estimated Annual Global Economic Values of Ecological Services Provided by Forests Should we be concerned about biodiversity? What we know: The Earth is losing species at an alarming rate In undisturbed ecosystems extinction = 1 species per decade Human activity is causing 10,000 species extinction per year or 27 per day! Threats to biodiversity Habitat destruction Invasive Species Pollution Human Population growth Overharvesting HIPPO Habitat destruction, invasive species, pollution, population (human), and overharvesting What are the main threats to biodiversity? I. Habitat destruction Habitat destruction, degradation, and fragmentation are probably the most important causes of extinction today Logged Rainforest in Malaysia What are the main threats to biodiversity? These hotspots of biodiversity = 1.5% of the Earth’s land, but if they were destroyed, 1/3 of Earth’s species would go extinct Habitat Fragmentation: fragmentation of an organism's habitat Building Roads into Previously Inaccessible Forests Habitat Fragmentation reduce population sizes Small populations are also especially vulnerable to catastrophic events Larger land can support more individual making species 1. less vulnerable to natural disasters 2. Genetic problems (less inbreeding) 3. Demographic uncertainty (chance all members of a single generation will be of the same sex The threats to biodiversity generally reduce population sizes of native species Managers try to maintain native populations well above their minimum viable population (MVP) sizes –the necessary population size to ensure between 90 and 95 percent probability of survival of a population 100 to 1000 years into the future II. Invasive Species Non native species that outcompetes with native species eventually reducing biodiversity People dumped pythons into everglades when their pets got too big Introduced in 1800’s for aesthetic reasons What are the main threats to biodiversity? 1890: 100 Starlings were introduced in NYC European Starling What are the main threats to biodiversity? Gift from Japan in 1876 to celebrate USA 100th year Kudzu U.S. Forest Invading Nonnative Insect Species and Disease Organisms Invasive species can carry pathogens Dutch elm disease transmitted to trees by elm bark beetles. Since 1930, the disease has spread from Ohio through most of the country, killing over half of the elm trees in the northern U.S. The direct threats of invasive species: preying on native species out-competing native species for food or other resources causing or carrying disease Releasing toxins preventing native species from reproducing or killing their young The indirect threats of invasive species Changing food webs: destroy or replace native food source The invasive species may provide little to no food value for wildlife. Decreasing biodiversity: outcompete native species or destroying native species Altering ecosystem conditions changing soil chemistry or the intensity of wildfires. What are the main threats to biodiversity? III. Pollution: Directly and Indirectly kills plants and animals What are the main threats to biodiversity? More people = increase in resources IV. Population The human population explosion is the root cause of the other threats Fig. 52.22 What are the main threats to biodiversity? V. Overharvesting Harvesting at rates exceeding the ability of populations to rebound is not sustainable Atlantic Cod Fishing Nets Animals Killed because they pose a threat to humans or livestock Pet Trades: Overharvesting Endangered Species Management and Biodiversity Protection 1. Hunting and fishing laws protect populations NO hunting during mating season 2. Endangered Species Act of 1973 Endangered species: imminent danger of extinction Threatened species: likely to become endangered Vulnerable species: naturally rare or locally depleted by human activity Which species do we save? 5 billion to protect all species on list Keystone species Indicator species Umbrella species Flagship species A. Keystone species species affect many other organisms in an ecosystem and help to determine the types and numbers of various other species in a community. Example: weevil preys on Eurasian Watermilfoil Without the weevil, the Eurasian Watermilfoil would overtake the plant species decreasing biodiversity B. Indicator Species a species thought to be sensitive to and therefore to serve as an early warning indicator of environmental changes such as global warming Example River otters have been used as indicators of healthy, clean river systems C. Umbrella Species these species indirectly protects the many other species that make up the ecological community of its habitat Example: Bees pollinate many different types of flowers and fruit bearing plants D. Flagship Species species are chosen for their vulnerability or because they will appeal to the public example: panda bear What cost is too much? Save Salmon or reduce cost to electricity consumers? Convention on International Trade in Endangered Species (CITES) Illegal to export or important animals or animal body parts What can you do to help? Plant a tree Recycle paper and buy recycled paper products Choose wood alternative products for decks, fencing, furniture Remove invasive plants from your garden and replace with native plants Don’t transplant plants or seeds