Biodiversity. The Biosphere. The sum of Earth’s ecosystems, the Biosphere encompasses all parts of the planet inhabited by living things.
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The Biosphere • The sum of Earth’s ecosystems, the Biosphere encompasses all parts of the planet inhabited by living things. • About 1.8 million species had been identified and named by biologists, although the best estimates of how many there actually are is around 8.7 million (PLOS 2011) • For at least 3.8 billion years, a complex web of life has been evolving here on Earth.
Biodiversity • Biodiversity- short for biological diversity - is the variety of all organisms currently living, and their interactions • Scientists often speak of three levels of diversity - species, genetic, and ecosystem diversity. Ecosystem Species Genetic
Terrestrial Biomes The term biome refers to a broad category of terrestrial ecosystem, characterized by distinctive vegetation and soil types. Biomes are a good way of visualizing biodiversity distribution
What IS Species Biodiversity? • A dynamic interaction between the processes of EXTINCTION and SPECIATION • A snapshot (temporary) • 99% of everything that has EVER lived on Earth is now EXTINCT!
Global Distribution of Biodiversity • Greatest in areas where NPP is greatest • Terrestrial: toward Equator - Why? • Aquatic: near shore, marine upwellings – Why?
Endemism The % of species in an area that are found NOWHERE else on Earth
Why Is Island Biodiversity Sometimes Very High? • Immigration • Isolation • Extinction • More rapid evolution?
Importance of Biodiversity Reasons human cultures value biodiversity:The rich variety of species in biological communities gives us food, wood, fibers, energy, raw materials, industrial chemicals, and medicines, all of which pour hundreds of millions of dollars into the world economy each year. Moreover, people have a natural affinity for nature, a sense of “biophilia,” wherein they assign a non-utilitarian value to a tree, a forest, and wild species of all kinds (E. O. Wilson).
Pollination For every third bite you take, you can thank a pollinator. Air and Water Purification Biodiversity maintains the air we breathe and the water we drink. Climate Modification By giving off moisture through their leaves and providing shade, plants help keep us and other animals cool. Drought and Flood Control Plant communities, especially forests and wetlands, help control floods. Cycling of Nutrients The elements and compounds that sustain us are cycled endlessly through living things and through the environment. Importance of Biodiversity
Habitat Natural ecosystems provide habitat for the world’s species (forests, wetlands, estuaries, lakes, and rivers – the world’s nurseries). Food All of our food comes from other organisms. Natural Pest Control Services Natural predators control potential and disease-carrying organisms in the world. Drugs and Medicines Living organisms provide us with many drugs and medicines. Importance of Biodiversity
Factors Leading to Biodiversity Loss Multiple forces entrained by human activity reinforce one another and force species down. These factors are summarized by conservation biologists under the acronym HIPPCO (Wilson 2002). • Habitat Destruction • Invasive Species • Pollution • Population Growth • Climate Change • Overexploitation
Habitat Destruction Estimates predict that a full one-fifth of the species in the world could become extinct within the next 100 years due to deforestation in Southeast Asia alone (Brook 2003). Habitat loss is the main threat facing 85% of all endangered species (IUCN 2012)
Invasive Species The Nile perch has been the principal contributor to the extinction of over 200 endemic fish species since it was introduced to Lake Victoria (East Africa) in 1954 (ISSG Database).
Invasive Species • A species that is not native to a region • Threaten native species by outcompeting them for resources • Primary reason: lack of predators! • Ex. Tallow tree, nutria
Population Growth The current threat to biodiversity stems primarily from expanding human population and increased human consumption of natural resources. THE WORLD POPULATION HAS TRIPLED IN THE LAST 70 YEARS.Based on the present rate of population growth. One could conservatively predict the population to be by the year: 2,050 AD 12 Billion ???2,100 AD 24 Billion ???2,150 AD 48 Billion ???2,200 AD 96 Billion ??? 2,250 AD 192 Billion ??? 2,300 AD 384 Billion ??? http://www.edu.ue-foundation.org/worldpop.html
Pollution There has been widespread death of thousands of seals in recent years, likely due to the accumulation of chlorinated hydrocarbons (DDT, PCB’s) and dioxins in fat (Cunningham, Cunningham 2003).
Climate Change Global Warming has already caused one species level extinction, that of Costa Rica’s golden toad (Pounds 1999). A conservative estimate states 24% of the world’s species will become extinct within the next 50 years due to global warming (Thomas 2004).
Over-exploitation Over-harvesting has triggered the Red-Listing of 14% of threatened mammals and 11% of birds globally (Rosser 2002).
Only 107 Yellow-Crested Cockatoos in the wild • Salmon Cockatoo is “endangered” • THANKS, Cee-Lo…
(03/25/2013) On Friday, March 15th Thai authorities arrested a 38-year-old man attempting to collect a bag containing 54 ploughshare tortoises (Astrochelys yniphora) and 21 radiated tortoises (Astrochelys radiata) in Suvarnabhumi International Airport. Found only in Madagascar both species are listed as Critically Endangered and protected under the Convention on International Trade in Endangered Species (CITES). This haul represents more than 10% of the remaining wild population of Ploughshare Tortoises!
The Reality • During the past 150 years, humans have directly impacted and altered close to 47% of the global land area (Groombridge 2002). • An area of 76,000 km2 of tropical rainforest is being cleared annually – an area the size of West Virginia or Costa Rica (FAO 2000). • Current extinction rates are estimated at 100-1000 times greater than pre-human rates (Pimm, 1995). • We have caused the extinction of 5-20% of the species in many groups of organisms (Chapin 2000). • According to Wilson, should world conditions remain the same, at least one-fifth of the world’s species will become extinct by 2030 (Wilson 2002).
We have to stop pretending this is a “developing country” problem • We are living in the “6th Mass Extinction”
The Endangered Species Act (1973) The purpose of the ESA is to protect and recover imperiled species and theecosystems/habitats upon which they depend. It is administered by the U.S. Fish and Wildlife Service and the Commerce Department’s National Marine Fisheries Service (NMFS). Under the ESA, species may be listed as either endangered or threatened. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range. “Threatened” means a species is likely to become endangered within the foreseeable future. Still On The List Recently “De-Listed” American Alligator Grey Wolf Peregrine Falcon Grizzly Bear • Bald Eagle • Florida Manatee • Whooping Crane • Black-footed Ferret