Unit 6 Exam Study Guide

Endemic

(one that lives only in a single area) more likely to become extinct than a widely distributed species • Species with specific needs more likely to become extinct • Example: giant pandas endemic to China's bamboo forests eat mainly bamboo - Population has declined from 100,000 to 1,600 individuals

Hot Spots

- A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction. - The term biodiversity hotspot specifically refers to 25 biologically rich areas around the world that have lost at least 70 percent of their original habitat. - The remaining natural habitat in these biodiversity hotspots amounts to just 1.4 percent of the land surface of the planet, yet supports nearly 60 percent of the world's plant, bird, mammal, reptile, and amphibian species. - It must have at least 1,500 vascular plants as endemics — which is to say, it must have a high percentage of plant life found nowhere else on the planet. A hotspot, in other words, is irreplaceable. - It must have 30% or less of its original natural vegetation. In other words, it must be threatened.

bioaccumulation

- Acidic water moving through the soil causes nutrient loss - Trees more likely to die, especially at higher elevations • Bioaccumulation - Pollutant storage in an organism's tissues • Some plants can bioaccumulate toxic substances - Useful in phytoremediation of polluted soil - buildup of harmful chemicals

Biosphere

- All places on Earth where life exists - Geographical distribution of species depends largely on climate

Review the different biomes Dry Shrublands and Woodlands

- Biome dominated by fire-adapted shrubs - Occurs typically on the western coast of continents - Between 30 and 40 degrees north or south latitude - Features hot, dry summers and mild, wet winters - Dry woodland - Slightly more rain allows short trees to grow - like Lion King tree

Review the different biomes Tropical Savannas

- Broad belts of grasslands with a few scattered shrubs and trees - Lie between the tropical forests and hot deserts of Africa, India, and Australia - 35-60 inches of rain falls during the rainy season - Wildlife is abundant, esp. In African savannas

Review the different biomes Coniferous Forests

- Conifers - - Evergreen trees with seed-bearing ones - Leaves are typically needle-shaped - Tolerant of cold, drought, and poor soil - pine cones - Boreal forest - - Sweeps across northern Asia, Europe, and North America - Montane coniferous forests - - Extend southward through the great mountain ranges of North America

Desert Characteristics

- Deserts receive an average of 10 centimeters or less rainfall per year - Cover about one-fifth of the Earth's surface - Many are located about 30 degrees north and south latitude - Or in the rain shadow of a mountain range - Lack of rainfall keeps humidity low - Soils have very little topsoil - Plant life has adaptations to reduce water loss - A community that can include cyanobacteria, lichens, mosses, and fungi - Secrete organic molecules that glue them to the soil - Crust holds soil particles in place - When fragile connections in the crust are broken: - Soil can blow away - Blown soil buries the crust in other areas - Killing additional organisms

Review the different biomes Deserts & Desert Crust

- Deserts receive an average of 10 centimeters or less rainfall per year - Cover about one-fifth of the Earth's surface - Many are located about 30 degrees north and south latitude - Or in the rain shadow of a mountain range - Lack of rainfall keeps humidity low - Soils have very little topsoil - Plant life has adaptations to reduce water loss - A community that can include cyanobacteria, lichens, mosses, and fungi - Secrete organic molecules that glue them to the soil - Crust holds soil particles in place - When fragile connections in the crust are broken: - Soil can blow away - Blown soil buries the crust in other areas - Killing additional organisms

Effects of Ozone Thinning (Hole)

- Exposure to higher levels of UV radiation - causes skin cancer - harms wildlife - slows rate of photosynthesis in plants and producers - Chlorofluorocarbons (CFCs) are the main ozone destroyers - Once widely used as propellants, coolants, and in plastic foam - 1987 Montreal Protocol phased out CFCs

Number of Mass Extinctions

- Five - Five major extinction events occurred in past - Current extinction rate is similar to rates during those mass extinctions - Humans are the driving force of the current extinction (en route to Number 6) - Arrival of humans probably caused the extinction of many large animals in Australia and North America 40,000 - 10,000 years ago - possibly by hunting

Review the different biomes Temperate deciduous forests

- Form in the Northern Hemisphere - Eastern North America, Western and Central Europe, and parts of Asia including Japan - Warm summers and cool winters - Feature rich soil and a somewhat open canopy - Allows shorter understory plants to flourish - Grazing deer and seed-eating animals live in North America's temperate forests - Wolves and mountain lions largely eliminated - gatlinburg

Temperate deciduous forest

- Form in the Northern Hemisphere - Eastern North America, Western and Central Europe, and parts of Asia including Japan - Warm summers and cool winters - Feature rich soil and a somewhat open canopy - Allows shorter understory plants to flourish - Grazing deer and seed-eating animals live in North America's temperate forests - Wolves and mountain lions largely eliminated - gatlinburg

Review the different biomes Grasslands

- Grasslands form in the interior of continents - Soil is rich, with deep topsoil - Annual rainfall enough to prevent desert conditions - But not enough to support woodlands - Low growing grasses can withstand strong winds and periods of drought - Most tallgrass prairie converted to cropland - Elk, antelope, bison, and wolves occupied this area in the past

Mass Extinction

- Increased rate of extinction over short time period - Past mass extinctions caused by asteroid impact, volcanic eruption - Not all lineages are equally successful

Ecoregion

- Land or aquatic regions characterized by climate, geography, and the species found there - Most widely used ecoregion system developed by the World Wildlife Fund

Know parts of a lake (zones)

- Littoral Zone - Limnetic Zone - Profundal Zone

Evidence of Extinction

- More recent extinctions clearly attributable to humans - World Conservation Union has documented 800 species that have become extinct since 1500 - Example: dodo bird that lived on Mauritius island in the Indian Ocean - Birds plentiful in 1600 when Dutch sailors first arrived - 80 years later, the birds were extinct - Cause: destruction of nests and habitats by rats, cats, and pigs introduced by the sailors

Current Diversity and Threats

- Number of currently living species - estimated at 5 million to 50 million - Fewer than 2 million have been named

Review the different biomes Tropical rain forests

- Occur between latitudes 10 degrees north and south of the Equator - get 50-80 inches of rain yearly - Photosynthesis continues year-round - Great primary production of any land biome - Most structurally complex and species-rich biome - Trees form a closed canopy - Soils are highly weathered, poor in nutrients - Deforestation threatens humans and wildlife

2) Alpine Tundra

- Occurs at high altitudes throughout the world - No permafrost - Patches of snow persist year-round - Soil is thin and small-leafed, woody shrubs survive where soil has accumulated to a greater depth - Strong winds discourage free growth

1) Arctic Tundra

- Occurs between the polar ice cap and the belts of boreal forests in the Northern Hemisphere - Most is in Russia and Canada - Earth's youngest biome - Harsh conditions - Snow covers the ground as much as nine months of the year - Permafrost under top layer of soil - Home to lichens and shallow-rooted, low growing plants

Causes of Species Declines

- Over harvesting Species - - Example: Overharvesting white abalone in the 1970s reduced the population to one percent of its original size • Listed as endangered in 2001 • Current population density too low for reproduction in the wild • Captive breeding program undertaken - Example: Elephants killed for their tusks and rhinos for their horns

Ozone Layer Hole

- Region of high ozone concentration in the upper atmosphere - Benefits living organisms by absorbing most UV radiation from incoming sunlight - UV radiation causes mutations - Thinning of the ozone layer noticed in the 1970s - By mid-1980's, ozone thinning over Antarctica was so pronounced it became known as a hole

Review the different biomes Broadleaf Forests

- Semi-evergreen forests - Occur in the humid tropics of Southeast Asia and India - Broadleaf trees that retain leaves year-round - And deciduous trees - hunger games

Results of Global Warming

- Warmer than normal temperatures cause deciduous trees to leaf out earlier - Animal migration and breeding patterns change - Some animals cannot quickly adjust to the temperature change - Example: Reef-building corals - Incidence of human diseases will rise - Melting Glaciers

Results of Deforestation

- With high population growth rates and cultural practices, (e.g. agriculture, deforestation), humans become major agents of extinction - Amount of forested land currently stable - North America, Europe & China - Tropical forests continue to disappear at a high rate - Brazil clearing forests to create pasture for cattle for beef export - Deforestation encourages flooding, and raises landslide risk - can be very difficult to reverse Deforestation threatens humans and wildlife

Review the different biomes Biome

- areas of land characterized by climate and predominant vegetation - Most include areas on different continents - Depends mainly on rainfall and temperature - Soils also influence biome distribution - Primary production varies among biomes - Species living in widely separated parts of a biome often have similar body plans - Result of morphological convergence

Human Impacts of the Biosphere (Biosphere --> Where life lives)

- remote regions no longer beyond the reach of human explorers - Or beyond the reach of our influence - Polar bears hunting on the ice-covered Arctic sea - Threatened by rise in greenhouse gases - Their bodies contain surprisingly high levels of mercury and pesticides - In many areas of the globe, humans out-compete other species for resources

Review the different biomes Tundra (Arctic and Alpine)

Arctic - Occurs between the polar ice cap and the belts of boreal forests in the Northern Hemisphere - Most is in Russia and Canada - Earth's youngest biome - Harsh conditions - Snow covers the ground as much as nine months of the year - Permafrost under top layer of soil - Home to lichens and shallow-rooted, low growing plants Alpine - Occurs at high altitudes throughout the world - No permafrost - Patches of snow persist year-round - Soil is thin and small-leafed, woody shrubs survive where soil has accumulated to a greater depth - Strong winds discourage free growth

Types of Tundra

Arctic and Alpine

Biomes

Areas of land characterized by climate and predominant vegetation - Most include areas on different continents - Depends mainly on rainfall and temperature • Soils also influence biome distribution • Primary production varies among biomes • Species living in widely separated parts of a biome often have similar body plans - Result of morphological convergence

Bioaccumulation

Bioaccumulation is the accumulation of substances, such as pesticides, or other chemicals in an organism. • Acidic water moving through the soil causes nutrient loss - Trees more likely to die, especially at higher elevations • Bioaccumulation - Pollutant storage in an organism's tissues • Some plants can bioaccumulate toxic substances - Useful in phytoremediation of polluted soil

The Extinction Crisis

Extinction --> a natural process - scientists estimate 99% of all species that ever lived are now extinct Mass Extinction --> - increased rate of extinction over short time period - Past mass extinctions caused by asteroid impact, volcanic eruption - not all lineages are equally successful

conservation biology

Field that surveys the range of biodiversity and finds ways to maintain and use it to benefit human populations

What happens to air as it is cooled?​

It sinks.

Locations of deserts as in latitude

Many are located about 30 degrees north and south latitude - or in the rain shadow of a mountain range

Profundal Zone

Many lakes (but few ponds) are so deep that not enough light reaches here to support net primary productivity. Therefore, this zone depends for its calories on the drifting down of organic matter from the littoral and limnetic zones. The profundal zone is chiefly inhabited by primary consumers that are either attached to or crawl along the sediments at the bottom of the lake. Such bottom-dwelling animals are called the benthos. The sediments underlying the profundal zone also support a large population of bacteria and fungi. These decomposers break down the organic matter reaching them, releasing inorganic nutrients for recycling.

Endangered Species

One currently at a high risk of extinction in the wild

Threatened Species

One likely to become endangered in the future

Thermocline

Summer. Sun warms the upper water, which floats on a thermocline, a layer across which temperature changes abruptly. Upper and lower water do not mix because of this thermal boundary. Fall → Upper water cools and sinks downward, eliminating the thermocline. Vertical currents mix water that was separated during the summer.

Rocky and Sandy Coastlines

Support ecosystems of the intertidal zone • Ocean's shoreline is described as a littoral zone - Upper littoral zone receives ocean spray - Middle littoral zone typically underwater at high tide and dry at low tide - Lower littoral zone is rarely exposed, and has most diversity - Zones easily visible on a rocky shoreline • Barnacles, algae, snails

The Great Pacific Garbage Patch is a region of the north central Pacific where a high concentration of confetti-like plastic particles swirl slowly around an area as large as the state of ____.​

Texas

A plant pathologist, a scientist who studies plant diseases, examines a tree that has burnt leaves, is mineral deficient, and has several diseases. The plant pathologist concludes the tree's symptoms are most likely the direct result of ____.

acid rain

The genetic diversity within a species of a given region is called the ____.​

biodiversity

The increased concentration of toxins as they move up through the food chain is called ____.​

biological magnification

Which was responsible for destruction of the ozone layer?​

chlorofluorocarbons​

Global movements and circulation of air and ocean currents not only influence global climate, but also ____.​

circulate pollutants

The distribution of major biomes is controlled mainly by ____.​

climate

Which way do ocean currents circulate in the Northern Hemisphere?​

clockwise

El Nina

cooler

A(n) ____ species resides where it evolved, and is found nowhere else on Earth.​

endemic

Which North American biome has mostly disappeared because of extensive farming of wheat and corn?​

grasslands

Littoral Zone

is the near shore area where sunlight penetrates all the way to the sediment and allows aquatic plants (macrophytes) to grow. The zone close to shore. Here light reaches all the way to the bottom. The producers are plants rooted to the bottom and algae attached to the plants and to any other solid substrate. The consumers include - tiny crustaceans - flatworms - insect larvae snails - frogs, fish, and turtles.

Limnetic Zone

is the open water area where light does not generally penetrate all the way to the bottom. - This is the layer of open water where photosynthesis can occur. As one descends deeper in the limnetic zone, the amount of light decreases until a depth is reached where the rate of photosynthesis becomes equal to the rate of respiration. At this level, net primary production no longer occurs. - The limnetic zone is shallower in turbid water than in clear and is a more prominent feature of lakes than of ponds. - Life in the limnetic zone is dominated by floating microorganisms - called plankton actively swimming animals - called nekton. The producers in this ecosystem are planktonic algae. - The primary consumers include such animals as microscopic crustaceans and rotifers - the so-called zooplankton. - The secondary (and higher) consumers are swimming insects and fish. These nekton usually move freely between the littoral and limnetic zones.

What characterizes a biome?​

its climate and main type of vegetation

Because all commercially produced energy has some kind of negative environmental impact, it is a good idea to simply use ____.​

less energy

Protecting biodiversity can be problematic even for developed countries because ____.​

people fear economic consequences​

Exotic Species Definition

resident of an established community that became resident elsewhere

summer and fall

thermocline

Climate is the ____.​

​average weather conditions an area receives over a long interval

A characteristic of a temperate deciduous forest biome that differs from a tropical rainforest biome is that in a deciduous forest, ____.​

​the trees shed their leaves (four season trees)e

Effects of El Nino

• Affects weather patterns worldwide and year-round • May cause outbreaks of cholera and malaria in certain regions • ENSO - Naturally occurring, irregularly timed fluctuation in sea surface temperature and wind patterns • Occurs in the equatorial Pacific - Conditions persist for six to 18 months - Influence felt most strongly along the western coast of South America • Causes a decline in primary productivity - Can have dramatic effects on fish and animal populations - hotter

Pattern of Global Air Circulation

• Air circulation pattern begins at the equator - Intense sunlight evaporates water from the ocean - Warm, moist air ascends - Air rises to higher altitudes, moves north and south and cools, releasing moisture as rain in tropical forests - When air has traveled to 30 degrees latitude: • It has lost most moisture and cooled • Continues along Earth's surface toward the poles

Air Movement at Higher Latitudes

• Air picks up heat and moisture and rises at about 60 degrees latitude - Resulting precipitation supports temperate forests • Cold, dry air descends near the poles - Polar deserts form • Major wind patterns - Trace a curved path relative to the Earth's surface

The Seafloor

• Benthic province - Ocean bottom • Seamounts - Undersea mountains - Abundance of life makes seamounts attractive to commercial fishing vessels • Hydrothermal vents - Hot, mineral-rich water spews out from an opening on the ocean floor

Acid Rain

• Caused by airborne sulfur and nitrogen oxides - Pollutants combine with water and fall as acidic precipitation • pH of unpolluted rain water is 5 or higher - Acid rain can be ten times more acidic • Consequences of acid rain - Prevents fish eggs from developing and kills adult fish - Burns tree leaves and alters the soil

Regional Effects

• Coastal breezes - Arise because of differences between the ability of water and land to absorb and release heat • In daytime, land warms faster • As air warms and rises, replaced by cooler offshore air • At night, land cools more quickly, so breezes reverse direction • Monsoons - Also arise from differential heating of water and land

Harmful Land Use Practices

• Desertification - the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture. - Conversion of grassland or woodlands to desert conditions - Can be caused by poor agricultural practices that encourage soil erosion - Can be caused by overgrazing grasslands Example: Dust Bowl of the mid-1930s - Portions of prairie in the Great Plains of the United States plowed under for crop planting - Winds lifted more than a billion tons of topsoil

Going With The Flow

• Earth's air and seas constantly circulate • March 2011: earthquake and tsunami hit Japan's northeast coast - Nuclear power plant was damaged and released some radioactive material - Winds carried radioisotopes eastward and were detected on the West coast of North America 60 hours later • Within 18 days, some radioisotopes had circled the globe

Loss of Microorganisms

• Endangered species listings have traditionally focused on vertebrates • Scientists have only recently begun to consider the threats to plants and invertebrates • Human impact on protists and fungi is largely unknown • ICUN does not assess threats to bacteria or archaea

Coastal Ecosystems

• Estuary - Partly enclosed body of water where freshwater from a river meets seawater - Freshwater floats on top of seawater where they meet - Examples: San Francisco Bay, Chesapeake Bay, Boston harbor, and Lake Ponchartrain • Continual refreshing of nutrients allows high primary productivity • Spartina: dominant plant in the salt marshes

Streams and Rivers

• Flowing water ecosystems - Begin as freshwater springs - Grow and merge to form rivers • Properties of a stream or river vary along its length - Streambed composition affects solute concentration - Cold, rapidly flowing water holds more oxygen than slow moving, warm water • Affects which species can live there

Reducing Negative Impacts

• Goal: live sustainably - Meet the needs of the present generation without reducing the ability of the future generations to meet their own needs • First step in sustainable living - Recognize the environmental consequences of one's lifestyle • People in industrialized nations use huge quantities of resources - Resource extraction negatively affects biodiversity

Benefits of Conservation

• Healthy ecosystems essential to human survival - Other organisms produce our oxygen and food - They remove CO2 from the air and break down wastes • Conservation biologists help make decisions about which regions should be targeted first - Identify biodiversity hot spots

Talking Trash

• Historically trash was buried unground or sent out to sea • We know now that burying garbage contaminates groundwater - And solid waste dumped into oceans harms marine life - Now illegal in the United States to dump solid waste into the sea - Plastic still constantly enters coastal waters

Body Accumulation of Pollutants

• In animals, pollutants accumulate in fatty tissues - Amount increases over time - Long-lived species have higher percentage of pollutants in body tissues - Older individuals have higher pollutant load than younger individuals • Trophic level also affects pollutant concentration - Concentration increases at higher trophic levels

Sunlight and Latitude

• In both hemispheres, the extent of the seasonal change in daylight increases with latitude • Reasons that equatorial regions receive more sunlight energy than higher latitudes - Sunlight has to travel through more atmosphere near the poles - Energy is dispersed over a larger surface area near the poles

Introduced Species

• Introduced species can threaten native plants and wildlife by displacing natives • Introduced pathogens can destroy species that evolved without defenses • Decline or loss of one species often threatens others - Example: buffalo clover was abundant when buffalo ranged in the American Midwest • Threatened by buffalo loss, competition from introduced plants and insects, and habitat loss

Freshwater Ecosystems

• Lake - Body of fresh water - Divided into zones (see Figure 47.26 on next slide) - Undergoes succession - changes over time • Newly formed lake is oligotrophic - Deep, clear, and nutrient-poor - Lake becomes eutrophic as sediments accumulate and plants take root • Lake undergoes seasonal changes

Preservation and Restoration

• Many ecologically important regions have been protected in ways that benefit people - Example: Monteverde Cloud Forest in Costa Rica was privately purchased and protected as a nature reserve • Tourism industry at the reserve benefits local people • Ecological restoration - Necessary when an ecosystem is so damaged that conservation will not restore it

Water Flow

• Millions of tons of debris from the tsunami entered the ocean - Most sank, but some was carried by surface currents - In early 2013, a Japanese fishing boat came ashore in Washington state • The same year, California received its first verified tsunami debris - Cesium 137-enriched water will be delivered to the west coast of North America during the period 2014 to 2020

Pollutants

• Natural or man-made substances released into soil, air, or water in greater than natural amounts - Some comes from point sources such as a factory - Others come from nonpoint sources such as oil runoff from roads and driveways

What We Can Do

• Nonrenewable mineral resources used in electronic devices - Such as phones, computers, televisions, and MP3 players - Reducing consumption by fixing existing products is a sustainable resource use • Recycling and reducing energy use have positive effects • Learn about threats to ecosystems in your own area

The Open Ocean

• Oceans have gradients of light, temperature, nutrients, and oxygen concentration • Pelagic province - Largely unexplored - Exploration requires submersible vessels • Neritic zone - Water over continental shelves

Effects of Global Climate Change

• Ongoing climate change - Affects ecosystems worldwide • Average temperatures are increasing - Glacial melting contributes to rising sea level • Average sea level increased eight inches over the past century • Waters of the upper Atlantic have become less salty at the poles • Rainfall patterns have been altered • Seawater is becoming more acidic

Rebuilding Wetlands

• Restoration work in Louisiana's coastal wetlands - Dams, levees, and channels cut through the marshes for oil exploration have caused losses of wetland - Work is underway to rebuild some that was lost - See Figure 48.17 on next slide

The Ocean, Landforms, and Climates

• Sea level at the equator is about 3 inches higher than at either pole - Gravity causes sea surface water to move toward the poles • Surface ocean currents - Circulate clockwise in the Northern Hemisphere - Counterclockwise in the Southern Hemisphere • Coastal currents affect coastal climates - Pacific Northwest summers are cool and foggy because the California current chills the air

Global Air Circulation Patterns

• The biosphere - All places on Earth where life exists - Geographical distribution of species depends largely on climate • Climate - Average weather conditions of an area • In June, the Northern hemisphere receives more intense sunlight than the Southern hemisphere - In December, the opposite is true

The Collective Impact

• Unthinking actions of billions of individuals - Greatest threat to biodiversity • Impact of a single person may be small - Collective behavior, for good or bad, will determine Earth's future

Coral Reefs

• Wave-resistant formations of calcium carbonate secreted by coral polyps • 75 percent located in Indian and Pacific Oceans • Healthy reef home to living corals and many other species - One-quarter of all marine fishes are associated with coral reefs • Australia's Great Barrier Reef is the largest existing reef