Biodiversity Life on Earth and How Were Losing

Biodiversity Life on Earth, and How We’re Losing It…

The Biosphere • The sum of Earth’s ecosystems, the Biosphere encompasses all parts of the planet inhabited by living things. • In 2002 about 1. 7 million species had been discovered and identified by biologists, although estimates of the true number of species on earth range from 3. 6 to over 10 million (Wilson 2002). • For at least 3. 8 billion years, a complex web of life has been evolving here on Earth.

Terrestrial Biomes The term biome refers to a major type of terrestrial ecosystem that typifies a broad geographical region.

Biodiversity • Biodiversity - short for biological diversity - is the variety of all living organisms and their interactions. • Scientists often speak of three levels of diversity - species, genetic, and ecosystem diversity. Ecosystem Species Genetic

What makes up Earth’s Biodiversity?

Global Distribution of Biodiversity n Greatest in areas where NPP is greatest n n Terrestrial: toward Equator - Why? Aquatic: near shore, marine upwellings – Why?

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).

Importance of Biodiversity • 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.

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 HIPPO + G (Wilson 2002). • Habitat Destruction • Invasive Species • Pollution • Population • Overharvesting • Global Warming

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).

Invasive Species The Nile perch has been the principal contributor to the extinction of over 200 endemic fish species since its introduction to Lake Victoria in 1954 (ISSG Database).

Invasive Species • A species that is not native to a region • Threaten native species by taking over resources • Ex. Tallow tree, nutria

Human Population Explosion • The current threat to biodiversity, and thus to the biosphere as we know it, stems primarily from expanding human populations and increased human consumption of natural resources. THE WORLD POPULATION HAS TRIPPLED 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).

Over-harvesting has triggered the Red-Listing of 14% of threatened mammals and 11% of birds globally (Rosser 2002).

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).

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 km 2 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 prehuman 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).

Hunting n Unregulated hunting – ex. Passenger pigeon in early 1900’s n n 2 billion legally hunted to extinction Dodos extinct on Mauritius

n Poaching n n illegal hunting, esp. in developing countries ($) Can mean the difference between starvation and survival Very hard to prevent Ex. African Elephant and White Rhino in Kenya

Each species is always dependent on other species n Keystone species - a species which is CRITICAL to the functioning of an ecosystem n n Many different species are dependent on it n If lost, the entire ecosystem is destroyed

Sea Otter – Keystone species n n n Otters lived in kelp beds, ate sea urchins Otters were hunted for pelts; disappeared Sea urchins multiplied; ate all kelp 1937, small group of otters found Otter numbers grew; sea urchins declined Kelp beds restored!!

Uses of Various Species (Economic Services) n Mass extinctions represent the loss of potential uses n Ex. Medicinal products - ~40% of all prescription drugs were originally made from living things

n Rosy periwinkle = leukemia n Cinchona = malaria n n n pineapple = tissue inflammation foxglove = cardiac stimulant

Development of future medicines? Loss of rainforests, etc. means loss of plant species n Possible cures or treatments for AIDS, Alzheimer’s, Multiple Sclerosis, Cancer, etc. n

Aesthetics n Once its gone, it can no longer be looked at, touched, or appreciated…

Endangered Species Act n n n First went into effect in 1973 Designed to identify and protect any plant or animal in danger of extinction (currently c. 1, 350) National Marine Fisheries Service (NMFS) is responsible for the oceans U. S. Fish & Wildlife Service (USFWS) is responsible for all others Four Provisions n n 1. Compile list of endangered or threatened species 2. These species must not be caught or killed 3. Gov. may not carry out projects that jeopardize their long-term survival 4. Species recovery plan for those in danger of extinction

n Endangered species – numbers have fallen so low it is likely to become extinct n Threatened species – likely to become endangered if not protected

Developers vs. Environmentalists n n Making money vs. saving species Construction of roads, drilling for oil in the Arctic, etc Compromises are usually reached Fear of government restrictions can deter people from reporting endangered spp. on their property!!

Worldwide Efforts to Prevent Extinctions n n n World Wildlife Fund Nature Conservancy Friends of the Earth Greenpeace International Union for the Conservation of Nature and Natural Resources (IUCN)

n Convention on International Trade in Endangered Species (CITES) n Slowed the poaching of Elephants by making ivory trade illegal n Restricts trade of animal parts for use in Chinese medicine n Earth Summit & Biodiversity Treaty – encourages wealthy countries to give $$$ to poorer countries for the protection of individual species

Saving Species n n Captive-breeding programs in zoos and wild animal parks Wild individuals are captured and bred for later release n n Ex. California condor Ex. Black-Footed Ferret

Botanical Gardens – storehouses of genetic diversity n Store around 90, 000 species of plants, many of which are threatened n

n Germ-Plasm Banks – store germ plasm, (genetic material in reproductive cells), in case the species become extinct n Plants = seeds n Animals = sperm/eggs

The Future of Biodiversity Conservation n Protect entire ecosystems instead of individual species only n Save most of the species in the ecosystem not just those on the endangered list n Health of the entire biosphere relies on preservation of individual ecosystems n Protect “Biodiversity Hotspots” n Look for the places where most of the species are found, and preserve them.