Biodiversity Biodiversity l Biodiversity the number and variety

Biodiversity

Biodiversity l Biodiversity - the number and variety of species on Earth. Ø number of known species is approximately 1. 4 million; most are insects Ø estimates of the actual number of species range from 10 to 100 million

Loss of Species Biodiversity is threatened by certain Biotic Factors: Ø Population growth: increased need for food and space. Ø Deforestation: the harvesting of trees for manufacturing. Ø This leads to HABITAT LOSS.

Loss of Species l The human population is growing so rapidly and changing the environment so dramatically, we are causing other species to become extinct at an increasing rate

Biodiversity is threatened by certain Biotic Factors: l Poaching - Illegal hunting for valuable animal products like tusks and tortoise shells.

Biodiversity is threatened by certain Biotic Factors: l Invasive Species - species of plants and animals occurring further than their normal distribution within an ecosystem. They do not have natural predators in the ecosystems where they are introduced. Ø Often they can outcompete organisms in the same niche. Ø They can also introduce pathogens and diseases that sicken and kill other animals in the ecosystem. Ø

Invasive Species l Example 1: Cane Toad Ø Came from Hawaii. It was introduced to Australia to eat cane grubs. The cane toad did not eat grubs and became a very big problem!

Invasive Species l Example 2: Zebra Mussels Ø Transported from Asia in ship ballast water. Their populations grew so out of control in some U. S. waters they clogged pipes of wastewater facilities creating a major mess and are likely to cause our native mussels to go extinct.

Invasive Species l Example 3: Phragmites Ø Introduced into the Chesapeake Bay ecosystem and has crowded out many native wetland plants.

Biodiversity is threatened by certain Abiotic Factors: l Pollution - a harmful side-effect of various activities. Eutrophication - when algae blooms kill SAV and decomposers deplete dissolved oxygen levels in water. Ø Bioaccumulation - when toxins become more concentrated in higher trophic levels. Ø Temperature - Increasing temperatures due to global warming can impact the species that live in a delicate range of temperatures like coral. Ø This is known as coral bleaching. ü Temperature can also increase the spread of disease. ü

Loss of Species l Extinction - when the last individual of a species dies. Ø habitat destruction is the #1 cause.

Loss of Species l Most extinctions are occurring in the tropical rainforest Ø rain forests cover approximately 7% of the Earth’s land surface, but contain approximately 50% of the world’s species

Why Save Species? l Biodiversity is one of the major factors of a healthy and stable ecosystem. BIODIVERSITY MAINTAINS ECOSYSTEM STABILITY!!! l Each species has a role to play in its ecosystem and each is dependent upon other species for survival

Why Save Species? l Keystone Species- a species that has a dominating influence on the composition of a community l Examples: sea otters, beavers

Why Save Species? l Practical Uses Ø about 40% of all prescription drugs are made from living organisms. ü ü Ø ex. Vinblastine - derived from rosy periwinkle is used to treat childhood leukemia. ex. Taxol - derived from the bark of the Pacific yew tree is used to treat cancer. Plant species not yet discovered might also provide food or medicine for the future

Why Save Species? l Personal values Ø Extinction leads to the loss of objects of fascination, wonder, and beauty.

Efforts to Prevent Extinctions l World Wildlife Fund (WWF) - works to protect biodiversity. l Nature Conservancy - manages a system of nature sanctuaries. l Friends of the Earth - lobbies governments and gives information to the public. l Greenpeace International - stages protests to help stop habitat destruction and the killing of endangered species. l International Union for the Conservation of Nature and Natural Resources collaboration of 200 governments and 300 private organizations that publishes the endangered species list and advises governments on natural resource management l Audubon - sponsors research, public awareness. and land acquisition

Future of Biodiversity Captive Breeding Programsl increases threatened or endangered species populations by breeding animals under carefully managed circumstances Ø Zoos ü and wild animal parks ex. California condor, Whooping cranes

Future of Biodiversity Botanical Gardens l storehouses plant species in hopes of maintaining genetic diversity. l lacks space and funds.

Future of Biodiversity Germ Plasm Banks l stores the genetic material contained within the organism for future use.

The Ecosystem Approach l l Concentrates on protecting entire ecosystems rather than individual species By concentrating on entire ecosystems, we may be able to save most of the species in an ecosystem. Ø The health of the entire biosphere depends on the preservation of individual ecosystems.

The Ecosystem Approach l To protect biodiversity worldwide, conservationists suggest that at least 10% of the earth’s land be set aside as protected reserves; primarily biodiversity “hot spots”

The Ecosystem Approach l Biodiversity “hot spots” are places in the world that have many different species living in one place.