Presentation on theme: "What is Biodiversity? Biodiversity is the variety or richness of life at all structural levels (molecular/genetic, species, ecosystem). It is an essential."— Presentation transcript:
1What is Biodiversity?Biodiversity is the variety or richness of life at all structural levels (molecular/genetic, species, ecosystem). It is an essential renewable resource. It is exploited and depleted as a result of the “Tragedy of the Commons” phenomenon. The current rate of biodiversity loss is comparable to previous extinction events.
2Why is biodiversity important? Biodiversity provides us with:Natural Resources (food, water, wood,energy, and medicines)Natural (Ecosystem) Services including: air and water purification, soil fertility, waste disposal, pest control)Aesthetic pleasure
3H Habitat loss, including that caused by human-induced climate change. “The decline of Earth’s biodiversity is an unintended consequence of multiple factors that have been enhanced by human activity. They can be summarized by the acronym HIPPO, with the order of the letters corresponding to their rank in destructiveness.”H Habitat loss, including that caused by human-induced climate change.I Invasive species (harmful aliens, including predators, diseases, and competitors that displace native speciesP PollutionP Population, Human overpopulation to be exact, a root cause of the other four factorsO Overharvesting, Overuse (hunting,fishing, gathering)E. O. Wilson “The Creation”
4Habitat loss/destruction Habitat loss is the greatestreason for biodiversity loss.Habitat loss is due to:Conversion of natural areas to farms, houses, etcFragmentation of ecosystems by human activities, housing, transportation, agriculture etc.Simplification of genetic diversity and complex ecosystems by planting/selecting monocultures.
5Invasive / Exotic Species Invasive, exotic species introduced from elsewhere outcompete native species because they:Have no natural predatorsColonize disturbed habitats quicklyHave a high biotic potential (r-species)
6Cane Toads – The Conquest movie Cane Toads – The Conquest movie
7PollutionPollution (Oil spills, human agricultural waste, fertilization, pesticides, acid deposition, greenhouse gases etc) caused by human activities has a negative effect on biodiversity
8Population, Human overpopulation that is. 6.8 Billion and counting. The expansion of human population and affluence, especially in the developing world harms natural ecosystems.
9Overharvesting, Overuse, Overexploitation Overhunting, overfishing, destructive harvesting practices (cyanide, dynamite), illegal trade, exotic pet industry
10Raven, Berg, and Hassenzahl put it this way HumanPopulationIncreaseLand use change(Habitat loss)IncreasingEconomicActivityIncreasingEconomicActivityDecliningBiologicalDiversityIncreased useof technologyIncreased useof technologySocial, politicaland culturalfactorsSocial, politicaland culturalfactorsIndirect(Underlyingcauses)Directcauses
11Characteristics shared by many endangered species include: Low reproductive rate (biotic potential)Feed at high trophic levels (apex predator)Large body sizeSpecialistSpecialized feeding habitsSpecialized nesting and/or breeding areasFixed migratory patternsFound in one place or regionRareCommercially valuableNegative human interactions including attacks on people or livestock
13Important Laws Protecting Biodiversity Lacey Act (1900) forbids interstate commerce of illegally killed wildlife. Modifications of act prevent importing dangerous non-native species.Endangered Species Act (ESA) of 1973 makes it illegal tokill, trap, uproot (plants), modify the habitat of, or engage incommerce of an endangered species or its parts.To designate a species as endangered or threatened, Fishand Wildlife Service or National Oceanic and AtmosphericAdministration must:List speciesDesignate critical habitat areas where species is foundDevelop a recovery plan to help species survive and thrive
14The rich variety of the natural world that Charles Darwin memorably imagined as an "entangled bank", and that E. O. Wilson labeled "biodiversity", is in crisis. The International Union for Conservation of Nature (IUCN) calculates that one-fifth of mammals and nearly one-third of amphibians are threatened with extinction. Some estimate that only half of the species alive today will survive to Others describe the pace of biodiversity loss as 100 times the rate of natural extinctions. Less-diverse ecosystems are less productive, less stable and less robust. So loss of biodiversity may weaken ecosystems and make them more fragile, especially in the face of climate change, with grave consequences for food security, among other things.Sara Abdulla, Chief Commissioning Editor, NatureMarch 2010
16This summary of the relative effects by the year 2100 is a composite derived from calculations carried out for 12 individual terrestrial and freshwater ecosystems by O. E. Sala et al. (Science287, 1770–1774; 2000). Overall, changes in land use constitute the main estimated impact on biodiversity, but the pattern varies considerably for different ecosystems. According to Sala and colleagues' calculations, climate change will have the strongest effect on Arctic, alpine and boreal ecosystems, whereas biotic exchange (that is, invasion by non-native species) will exert its main influence in lakes.