Human Effects on the Biosphere Chapter 44 Human Effects on the Biosphere

44.1 Why Are So Many Species Threatened of Endangered? All over the world, humans are _______________ wildlife _________ with our _____________, factories, and farms We also put species at __________ __________________________________ __________________ them Introducing ________________ competitors The rate of species extinctions is rising; many types of biomes are _____________

Why Are So Many Species Threatened of Endangered? (cont’d.) A species is considered endangered when one or more of its _______________ have declined _____________________ Endangered species A species that faces extinction in all or ____________________________ Threatened species _____________________ to become endangered in the near future

Why Are So Many Species Threatened of Endangered? (cont’d.) C Texas blind salamander. A White abalone. Figure 44.1 Examples of endangered species native to the United States. To learn more about these and other threatened and endangered species, visit the United States Fish and Wildlife Service’s endangered species website at www.fws.gov/endangered/. D Florida perforate reindeer lichen. B Pyne’s ground plum.

Why Are So Many Species Threatened of Endangered? (cont’d.) Human activities threaten other species by destroying or ____________________ Around the globe, _______________ of habitats by ______________, ____________, and _________________ are major contributors to species loss

44.2 What Are the Effects of Desertification and Deforestation? ________________ occurs when ______________ or grazing removes plants and _____________ topsoil to ___________________ Fewer plants means less _____________; rainfall decreases In a _____________________ cycle, drought encourages desertification, which ____________ drought

What Are the Effects of Desertification and Deforestation? (cont’d.) Figure 44.2 Dust storms, one outcome of desertification A Dust cloud in the Great Plains during the 1930s. B Dust blows across the Atlantic from North Africa.

What Are the Effects of Desertification and Deforestation? (cont’d.) _____________________ continue to disappear at an ___________________ In addition to ______________ destruction of forest organisms, deforestation encourages _______________, and raises __________________ in hilly areas Deforestation also affects ________________ – temperatures rise, and reduced transpiration results in less rainfall Figure 43.2 Latitudinal variation in the intensity of sunlight at ground level.

What Are the Effects of Desertification and Deforestation? (cont’d.) Forests take up and store huge amounts of _______________, so deforestation also contributes to global climate change Deforested areas also become __________________ Experimental deforestation increased ______________ of essential soil nutrients such as ____________ (compared with undisturbed forest)

What Are the Effects of Desertification and Deforestation? (cont’d.) Figure 44.3 Deforestation. Cropland that once was rainforest extends right up to the edge of Iguaçu national park, a World Heritage site that straddles the border between Brazil and Argentina.

ANIMATION: Hubbard Brook Experiment Figure 44..4 {Animated} Effect of experimental deforestation on nutrient losses from soil. After deforestation, calcium (Ca) levels in runoff increased sixfold (gray). An undisturbed plot in the same forest showed no increase during this time (green). To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE

44.3 How Does Trash Degrade Habitats? Buried in the ground (such as lead from batteries) can ________________ groundwater ____________ at sea (such as ___________) harms marine life Plastic and other garbage that enters our _____________________ for many years Avoid buying plastics, or be sure to ____________ or dispose of them properly

How Does Trash Degrade Habitats? (cont’d.) Figure 44.5 Perils of plastic A Juvenile sea lion with ring of discarded plastic around its neck. As the animal grows, the plastic will cut into its neck, causing a wound and impairing its ability to feed. B Recently deceased Laysan albatross chick, dissected to reveal the contents of its gut. Scientists found more than 300 pieces of plastic inside the bird. One of the pieces had punctured its gut wall, resulting in its death. The chick was fed the plastic by its parents, who gathered the material from the ocean surface, mistaking it for food. A B

44.4 What Are the Effects of Acid Rain? Pollutants disrupt ________________ processes of organisms ___________________ from coal-burning power plants, and ________________ from burning gas and oil, are common air pollutants Pollutant Substance that is released into the environment by human activities and _______________ with the function of organisms that _______________ in the absence of the substance or with lower levels

What Are the Effects of Acid Rain? (cont’d.) Dry acid ______________: dry dust particles coated with airborne _____________________ _________________ deposition (acid rain): pollutants combine with water and fall as acidic precipitation Acid rain _____________ rain that forms when sulfur dioxide and nitrogen oxides mix with water vapor in the atmosphere

What Are the Effects of Acid Rain? (cont’d.) Acid rain in aquatic habitats ____________ fish eggs from ____________ Kills adult fish Acid rain in forests Burns tree leaves Makes trees more ______________ to insects and __________________

What Are the Effects of Acid Rain? (cont’d.) Acid rain __________________ of soils Positive hydrogen ions ____________ positive nutrient ions such as calcium, causing nutrient loss Acidity causes soil particles to release metals, such as __________________________

ANIMATION: Effect of air pollution in forests Figure 44.6 {Animated} Acid rain in the United States. To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE

44.5 What Are the Effects of Ozone Depletion and Pollution? Ozone is said to be “______________, but _________________” In the upper atmosphere, the ozone (O3) layer ________________________ ultraviolet (UV) radiation that damages ____________ and causes mutations Near the ground, it is a __________________

What Are the Effects of Ozone Depletion and Pollution? (cont’d.) ___________________, scientists noticed that Earth’s ozone layer (10.5 to 17 miles above sea level) ______________, particularly over Antarctica (the “ozone hole”) In 1987, countries worldwide agreed to ______________________ of chlorofluorocarbons (CFCs) and other ozone-destroying chemicals – but existing CFCs break down _________________

What Are the Effects of Ozone Depletion and Pollution? (cont’d.) Antarctica Figure 44.7 Destruction of the ozone layer.

What Are the Effects of Ozone Depletion and Pollution? (cont’d.) Near the ground, __________________ eyes and _____________ tracts of humans and wildlife, and interferes with plant growth Ground-level ozone forms when nitrogen oxides and _________________ compounds released by burning or evaporating fossil fuels are exposed to sunlight Warm temperatures ____________________

44.6 What Are the Effects of Global Climate Change? Climate change is the most ___________ threat to habitats worldwide ___________________/meltwater from glaciers _____________ coastal wetlands Temperature changes disrupt ___________________ (e.g., tree flowering, animal migration, and breeding seasons) Some species are moving to higher latitudes or elevations; those that cannot move are ____________________

What Are the Effects of Global Climate Change? (cont’d.) Many _________________ are expected to change as rising land and sea temperatures ____________________, winds, and ________________ Examples Extremes in rainfall patterns: periods of ______________________ by unusually heavy rains Increase in ____________________

What Are the Effects of Global Climate Change? (cont’d.) Figure 44.8 Rising temperature. The temperature anomaly is the deviation from average temperature in the period 1951–1980.

What Are the Effects of Global Climate Change? (cont’d.) Muir Glacier in Alaska (1940) Figure 44.9 Melting glaciers, one sign of a warming world. Water from melting glaciers contributes to rising sea level. Muir Glacier in Alaska (2004)

44.7 What Is Conservation Biology? _________________ survey and seek ways to protect the world’s ____________________ Conservation biology Field of __________________ that surveys biodiversity and seeks ways to maintain and use it Biodiversity Of a region, the ___________________ within its species, ____________________, and ________________________

What Is Conservation Biology? (cont’d.) Biological ___________ (biodiversity) is measured at three levels: ______________ diversity within species ______________ diversity Biodiversity is ____________ at all three levels, in all regions

What Is Conservation Biology? (cont’d.) _____________ ecosystems are ____________ to human survival: Produce our ___________ and food ___________ , ____________, and ____________ wastes Prevent erosion and reduce risk of flooding Allow for new medicines to be _______________ compounds in wild species Encourage plant breeders to use genes in _____________ to protect and improve crops

What Is Conservation Biology? (cont’d.) People often _____________ environmental protections because they fear ______________________________ Conservation biologists help determine which __________________ be targeted for protection first by ____________ hot spots ____________ region with great biodiversity that is considered a high priority for conservation efforts

What Is Conservation Biology? (cont’d.) Figure 44.10 The location and conservation status of the land ecoregions deemed most important by the World Wildlife Fund.

What Is Conservation Biology? (cont’d.) Figure 44.11 Klamath–Siskiyou forest, one of North America’s critical ecoregions. Endangered northern spotted owls (inset) are endemic to this coniferous forest.

What Is Conservation Biology? (cont’d.) Ecological _______________ ________________ an area in an effort to restore or create a ______________ ecosystem Required when a natural ecosystem has been _______________________ Example: Louisiana’s coastal wetlands

What Is Conservation Biology? (cont’d.) Figure 44.12 Ecological restoration in Louisiana’s Sabine National Wildlife Refuge. Where marshland has become open water, sediments are barged in and marsh grasses are planted on them. The squares are new sediment with marsh grass.

44.8 How Can We Reduce Our Impact? Ultimately, the health of our planet depends on our ____________________ the principles of ____________________ _____________________ The goal is living _________________ Meeting the needs of the present generation _____________________________ of future generations to meet their own needs

How Can We Reduce Our Impact? (cont’d.) People in industrial nations use ___________________ of resources, and the ___________, ____________, and use of these resources has negative effects on biodiversity Example: In the U.S., an average new home contains about ___________ of copper wiring and _______________ Strips ____________________; produces waste; causes air and water pollution

How Can We Reduce Our Impact? (cont’d.) Figure 44.13 Environmental costs of resource extraction. A Bingham copper mine near Salt Lake City, Utah. This open pit mine is 4 kilometers (2.5 miles) wide and 1,200 meters (0.75 miles) deep, the largest man-made excavation on Earth. B Pelican covered with oil that accidentally escaped from a deep sea-drilling platform in the Gulf of Mexico. A B

How Can We Reduce Our Impact? (cont’d.) Figure 44.14 Volunteers restoring the Little Salmon River in Idaho so that salmon can migrate upstream to their breeding grounds.

44.9 A Long Reach In the Arctic, unusually warm temperatures are affecting the __________________ of sea ice melting and ______________ Polar bears can only reach their main prey by _______________________ Other threats – high amounts of _____________ and organic pesticides are carried to ______________ by winds and ocean currents Have been found in tissues of polar bears

A Long Reach (cont’d.) Eight countries, including the U.S., control __________________ and have rights to ______________, _______, and _________________ Melting ice sheets make it easier to _________________ and _______________ from the Arctic _______________ these resources will further harm Arctic species that are already threatened by global climate change

A Long Reach (cont’d.) Figure 43.15 Polar bears investigate an American submarine that surfaced in ice-covered Arctic waters.