Transcript Chapter 11
Chapter 11 Sustaining Terrestrial Biodiversity: The Ecosystem Approach Amy Kinnear and Emily Bold 3rd hour Objectives • How do biologists estimate extinction rates, and how do human activities affect these rates? Scientists use measurements and models to estimate extinction rates. Humans affect these rates because we are eliminating, degrading, and simplifying many biologically diverse environments- such as tropical forests, tropical coral reefs, wetlands, and estuaries- that serve as potential colonization sites for the emergence of new species. Objectives • Why should we care about protecting wild species? We should not cause the premature extinction of species because of the economic and ecological services they provide. It takes at least 5 million years for natural selection to rebuild the biodiversity we are likely to destroy during this century. Objectives • Which human activities endanger wildlife? The greatest threat to a species is the loss, degradation, and fragmenting of the place where it lives. Objectives • How can we help prevent premature extinction of species? Do not buy furs, ivory products, and other materials made from endangered or threatened animal species. Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics. Do not buy birds, snakes, tropical fish, etc. taken from the wild. Spread the word and talk to friends and relatives about this problem. Objectives • What is reconciliation ecology, and how can it help prevent premature extinction of species? Reconciliation ecology involves finding ways to share the places we dominate with other species. Vocabulary • Endangered Species - Wild species with so few individual survivors that the species could soon become extinct in all or most of its natural range. • Threatened Species - (also known as vulnerable species) Wild species that is still abundant in its natural range but is likely to become endangered because of a decline in numbers. • Local extinction - Occurs when a species is no longer found in an area it once inhabited but is still found elsewhere in the world. • Ecological extinction - Occurs when so few members of a species are left that it can no longer play its ecological roles in the biological communities where it’s found. • Biological extinction – A species is no longer found anywhere on the earth. Vocabulary • HIPPO - Habitat destruction, degradation, and fragmentation, Invasive (nonnative) species, Population growth (too many people consuming too many resources), Pollution, and Overharvesting. • Biotic pollution – Harmful ecological and economic effects from the presence of accidentally or deliberately introduced species into an ecosystems. • Convention on International Trade in Endangered Species (CITES) - This treaty, now signed by 169 countries, lists some 900 species that cannot be commercially traded as live specimens or wildlife products because they are in danger or extinction. CITES has helped reduce international trade in many threatened animals, including elephants, crocodiles, cheetahs, and chimpanzees. • Endangered Species Act of 1973 - Designed to identify and legally protect endangered species in the United States and abroad. Vocabulary • Egg Pulling – Involves collecting wild eggs laid by critically endangered birds species and then hatching them in zoos or research centers. • Captive Breeding – Some or all of the wild individuals of a critically endangered species are captured for breeding in captivity, with the aim of reintroducing the offspring into the wild. • Habitat Fragmentation – By roads, logging, agriculture, and urban development- occurs when a large, continuous area of habitat is reduced in area and divided into smaller more scattered, and isolated patches or habitat islands.