5Importance of Biodiversity Beauty – aesthetic standpointNature –Orgs are adapted to live together in communities; not always clear how orgs are related, so taking away one species can have a BROAD RANGE OF EFFECTS.The variety of lifeforms on Earth, all inter-connected to each other through food webs, makes our survival possible -- autotrophs, heterotrophs, decomposers all need one anotherBiodiversity provides crucial "ecosystem services"— Ex. clean water, breathable atmosphere, and natural climate control, upon which all species depend.
6The extermination of plant populations changes climates locally and has severe regional effects through disturbance of the water cycle.(Remember – transpiration releases 90% of all water taken in by a plant, and the water has been filtered as it passes through the plant itself…)
7Destruction of habitat severely limits the animal populations that can live in an area. (Threatened, Endangered, Extinction of species)
8Figure A hundred heartbeats from extinction: Philippine eagle (left), Chinese river dolphin (right)
9Ex. Beef, chicken, pork, fish, shellfish Ex. Penicillin came from mold People – Food, medicine, clothing and shelter are all derived from the abundant organic resources of the Earth.Ex. Beef, chicken, pork, fish, shellfishEx. Penicillin came from moldEx. Quinine (malaria treatment) came from bark of cinchona treeEx. Cotton from plant, wool from sheep, silk from wormsEx. Wood from trees
10Threats to Biodiversity Habitat lossHabitat Fragmentation (Biotic and Abiotic issues)Habitat degradation caused byair pollution, water pollution,land pollutionIntroduction of Exotic Species
11Habitat loss… Biggest threat to biodiversity When area to live is gone, orgs dieEx. deforestation
16Figure 55.6 The history of habitat reduction and fragmentation in a Wisconsin forest
17Biotic and Abiotic Issues of Fragmentation -some organisms need large areas to gather foodEx. LionsEx. Zebra-no migratory routes to re-establish populations lost due to natural disastersAbiotic:-climate can change-can cause EDGE EFFECT(different conditions along the boundaries of an ecosystem)
18Habitat Degradation Damage to habitat by pollution Three types of pollution: air, water, land
19Air pollution breathing problems irritation of membranes Burning of fossil fuels is biggest sourceOzone layer is being broken down by CFC’s (carbofluorocarbons) – found in refrigerators and air conditioners as coolants; this allows radiation to reach earth, causing genetic defects and cancer
20Figure 54.27a Erosion of Earth’s ozone shield: The ozone hole over the Antarctic
21Water PollutionDegrades aquatic habitats in streams, lakes, and oceansExcess fertilizers and animal waste get into streams and cause algal bloomsCoral reefs are destroyed when silt covers the living coral and they can’t photosynthesize or get to foodDetergents, heavy metals, and industrial chemicals in runoff cause sickness and death in aquatic orgsAbandoned drift nets trap dolphins, whales, fish, sea turtlesAcid precipitation is responsible for deterioration of forests and lakes, also damages plant tissues and interferes with plant growth.(sulfur dioxide from coal-burning factories and nitrogen oxides from exhausts combine with water vapor to form acid droplets of water vapor)Use of pesticides such as DDT – gets into water
22Figure 54.25 Biological magnification of DDT in a food chain
24Land Pollution Trash – solid waste Made up of cans, bottles, paper, plastic, metals, dirt, spoiled food, etc.Average American produces 1.8 kg of waste dailyLandfills take up space
25Introduction of Exotic Species New orgs introduced into an ecosystem; do not have any natural predators and is little competition with other orgs, so native species are at riskExotics may take over niches of native species and eventually replace the native species completely
26Greenhouse Effect and Global Warming In 1996, the United States was responsible for 23% of the world’s carbon dioxide emissions -- more than any other country.Carbon dioxide is the primary greenhouse gas, responsible for 60 % of global warming
27Extinction RatesExtinction has usually progressed at what scientists call a natural or background rate. Today the tempo is far faster.Many scientists believe this is the sixth great wave - the sixth mass extinction to affect life on Earth.We (humans) have more than doubled our numbers in half a century, and that is the most obvious reason why there is less room for any other species.We are taking their living room to grow our food, their food to feed ourselves.We are exploiting them, trading in them, squeezing them to the margins of existence - and beyond.
28Conservation efforts: Conservation Biology: studies methods and implements plans to protect biodiversity*legal protection of species*habitat preservation(sustainable use,habitat corridors)*reintroduction programs
29How can we prevent biodiversity loss? ResearchLegislationEducation/AwarenessSustainable use of habitats and fisheriesIntegration/Co-ordination
30What can you do? Be aware… Reuse and recycle Turn off water and lights CarpoolVote responsiblyVolunteerBe the teacher!