Section 6-3 Biodiversity: Sum total of the variety of organisms in the biosphere

Insects Bacteria Fungi Plants Protists Other Animals 54.4% 4.2% 18% 3.4% 0.3% 19.7% Section 6-3 Species Diversity

Value of Biodiversity Species of many kinds provide us with –Foods –Industrial products –Medicines –Rosy periwinkle Madagascar Cancer

Threats to Biodiversity Human activity can reduce biodiversity by: *altering habitats *hunting to extinction *introducing pollutants into food webs *introducing foreign species to new environments

Habitat Alteration Habitats supply organisms' needs and are a limited resource As habitats disappear, so do species Habitat fragmentation: –When an ecosystem is split into pieces –“biological islands” Smaller islands= fewer species and greater vulnerability

Demand for Wildlife Products Hunting for food and other products have led to the extinction of various species Endangered species protected today Hunting still threatens rare animals

Pollution Many forms of pollution threaten biodiversity Biomagnification: concentrations of a harmful substance increase in organisms at higher trophic levels in a food chain or food web

Introduced Species Accidentally or intentionally Reproduce rapidly Lack parasites and predators Cause ecological problems

Conserving Biodiversity Wise management of natural resources, including wildlife and habitat preservation

Conservation Strategies Protect entire ecosystems and single species Conservation regulations: –Maximize benefits and minimize costs

6.4 Charting a Course for the Future Researchers are gathering data to monitor and evaluate the effects of human activities on important systems in the biosphere. Two of these systems are the ozone layer and the global climate system.

Ozone Depletion Ozone Layer: –20-50 km up –Three O atoms –Pollutant at ground level –Absorbs UV rays Cancer Eye damage

Ozone Depletion Ozone “hole” –First discovered in 1970's over Antarctica –Has since grown larger –Similar “hole” over Arctic –CFC's

Chlorofluorocarbons Can damage ozone –Propellants Aerosal cans collants –Linger for a century –Began reducing in 1987 –Data is positive for long-term reduction

Global Climate Change Strong evidence that climate is changing Average atmospheric temperatures have risen about 0.6 Celsius degrees since late 19 th Century and 0.2 – 0.3 Celsius degrees since 's were the warmest recorded “Global Warming”

Evidence of Global Warming Earth's climate has changed repeatedly during its history –Human or natural? –Research focuses on describing warming trend, determining its cause and predicting its effects on the biosphere. CO2 emissions –Data shows Rising for 200 yrs –Greenhouse effect

Possible Effects of Global Warming Computer models (complex and assumption, so debatable) –Flooding –Droughts –Range expansion or extinction

Value of a Healthy Biosphere Ecosystem Services: –Solar energy –Production of oxygen –Climate regulation –Purifies water and air –Stores and distributes freshwater –Food production –Nursery habitats for wildlife –Detoxifies human and industrial waste –Natural pest and disease control –Manages soil erosion and runoff