Chapter 34
Which vegetation provides a major source of food to animals in savannas?
Grasses and forbs (small broadleaf plants) grow rapidly during the rainy season, providing a good food source for many animal species. Large grazing mammals must migrate to greener pastures and scattered watering holes during seasonal drought.
What kind of vegetation grows in savannas?
Grasses and forbs and some shurbs
Other than the poor soils and lack of moistures, what else limits invasion by trees?
Grazing animals and frequent fires, caused by lightning or human activity
What are some human impacts on tropical rain forests?
It is a common practice to clear the forest for lumber, or simply to burn it, farm the land for a few years, and then abandon it. Mining has also devastated large tracts of rain forest. Once stripped, the tropical rain forest recovers very slowly because the soil is so nutrient-poor.
Give an examples of how animals get nutrients and energy from sulfur bacteria living inside of them?
It's mutual benefit. For example, the red tips of the giant tube worms are respiratory surfaces that acquire oxygen and sulfide from the water. Bacteria living in a specialized organ in the worm's body get energy from the sulfide—a lot of energy.
what is the most important factor limiting plant growth for terrestrial ecosystems?
Lack of sunlight
What animals inhabit temperate grasslands?
Large grazing mammals, such as the bison and pronghorn of North America and the wild horses and sheep of the Asian steppes
What happens to vegetations when rainfall becomes scarce in tropical forests and tropical dry forests predominate?
. The plants found there are a mixture of thorny shrubs and deciduous trees and succulents.
what factors influence life in the biosphere?
1- energy sources 2- water 3- temperature 4- inorganic nutrients 5- Other Aquatic Factors 6- Other Terrestrial Factors
how many hours is day in tropical rainforests?
11-12 hours boiiiiiiiiii
What percentage of species do freshwater biomes include?
6%
Chapparal
A biome dominated by spiny evergreen shrubs adapted to periodic drought and fires; found where cold ocean currents circulate offshore, creating mild, rainy winters and long, hot, dry summers. (a Spanish word meaning "place of evergreen scrub oaks")
What causes biomes?
Climate and other abiotic factors of the environment
Where do plants obtain inorganic nutrients?
soil. Soil structure, pH, and nutrient content often play major roles in determining the distribution of plants.
what powers most ecosystems?
solar energy (photosynthesis)
Phytoplankton
algae and photosynthetic bacteria that drift passively in aquatic environments
Biotic
all of the organisms in the area, are the living component of the environment.
Pelagic Realm
all open water of ocean
Temperature
an important abiotic factor because of its effect on metabolism
What is the driest place on earth?
the Atacama Desert in Chile. there is often no rain at all for decades at a time.
What is the effect of ocean currents on regional climates?
the Gulf Stream circulates warm water northward from the Gulf of Mexico and makes the climate on the west coast of Great Britain warmer during winter than the coast of New England, which is actually farther south but is cooled by the Labrador Current flowing south from the coast of Greenland.
When do seasons happen?
the Northern Hemisphere tilts toward the sun in June, resulting in the long days of summer in that hemisphere. But during this time, days are short in the Southern Hemisphere and it is winter there. Conversely, the Southern Hemisphere tilts toward the sun in December, causing summer there and winter in the Northern Hemisphere.
What vegetation dominates chaparrals?
the perennial shrubs and annual plants especially during the wet winter and spring months.
What causes seasons?
the permanent tilt of the planet on its axis as it orbits the sun.
Give examples of abiotic factors
the physical and chemical factors such as temperature, forms of energy available, water, and nutrients.
Aphotic zone
the region of an aquatic ecosystem beneath the photic zone, where light does not penetrate enough for photosynthesis to take place (between 200 and 1,000 m (0.6 mile). some veryyyy little light does reach these depths.
The tropics
the region surrounding the equator between latitudes 23.5° north (the Tropic of Cancer) and 23.5° south (the Tropic of Capricorn), experience the greatest annual input and least seasonal variation in solar radiation.
What does it mean if the climate in two geographically separate areas is similar?
the same type of biome may occur in both places; notice on the map that each kind of biome occurs on at least two continents. (pic above)
What happens in the intertidal zone?
the shore is pounded by waves during high tide and exposed to the sun and drying winds during low tide.
Habitat
the specific environment it lives in, includes the biotic and abiotic factors present in its surroundings.
Continental self
the submerged parts of continents
Which biome is polar biome close to and what does that lead to?
the terrestrial polar biome is closely interconnected with the neighboring marine biome. Seals and marine birds, such as penguins, gulls, and skuas, feed in the ocean and visit the land or sea ice to rest and to breed.
How does grass survive fires in savannas?
their shoots are below ground.
Describe the soil of taigas?
thin and acidic, and the slow decomposition of conifer needles makes few nutrients available for plant growth. Most of the precipitation is in the form of snow.
What are the major biomes?
tropical rain forest, savanna, desert, chaparral, temperate grassland, temperate broadleaf forest, northern coniferous forest, tundra, polar ice, High mountains (not really a biome its a mix of coniferous forest and alpine tundra)
Describe the soil in tropical rainforests
typically poor. High temperatures and rainfall lead to rapid decomposition and release of nutrients. However, the nutrients are quickly taken up by the luxuriant vegetation or washed away by the frequent rains.
What does overfishing cause?
upset the species balance in some reef communities and greatly reduced diversity, and the widespread demise of reef-building corals in some regions has been attributed to climate change.
Which animals live in tundras?
Large herbivores include musk oxen and caribou, smaller animals are rodents called lemmings and a few predators, such as the arctic fox and snowy owl. . Many animals are migratory, using the tundra as a summer breeding ground. . During the brief warm season, the marshy ground supports the aquatic larvae of insects, providing food for migratory waterfowl, and clouds of mosquitoes often fill the tundra air.
temperate zones
Latitudes between the tropics and the Arctic Circle in the north and the Antarctic Circle in the south; regions with milder climates than the tropics or polar regions. Distinct seasonal variation occurs
Give an examples of how evolutionary adaptations help organisms live in certain temperatures?
archaeans living in hot springs have enzymes that function optimally at extremely high temperatures. Mammals and birds, such as the snowy owl in can remain considerably warmer than their surroundings and can be active at a fairly wide range of temperatures. Amphibians and reptiles, which gain most of their warmth by absorbing heat from their surroundings, have a more limited distribution.
what does The distribution and abundance of photosynthetic organisms (plants, algae, and photosynthetic bacteria) depend on?
availability of inorganic nutrients such as nitrogen and phosphorus.
What is the annual rainfall rate in temperate grasslands?
averages 25-75 cm (about 10-30 inches) and periodic severe droughts occur
Where do the rays strike Earth's surface at a slant?
away from the equator
What powers dark environments such as caves or hydrothermal vents?
bacteria that extract energy from inorganic chemicals.
Why does most photosynthesis occur on the surface of the water?
because Microorganisms and suspended particles, as well as the water itself, absorb light and prevent it from penetrating beyond certain depths.
Why does Earth receives an uneven distribution of solar energy?
because of its curvature.
why do wetlands support the growth of aquatic plants?
because they are Covered with water either permanently or periodically
Why are vegetations important in the nine biomes?
because they provide food, shelter, nesting sites, and much of the organic material for decomposers, plants build the foundation for the communities of animals, fungi, and microorganisms that are characteristic of each biome.
Mudflats and salt marshes
coastal wetlands that often border estuaries and experience tidal fluctuations.
what causes the north and south temperate zones, especially latitudes around 60°, tend to be relatively wet?
Notice that some of the descending air heads into the latitudes above 30° north and south. At first these air masses pick up moisture, but they tend to drop it as they cool at higher latitudes.
What explains the absence of trees in tundras?
Permafrost prevents the roots of plants from penetrating very far into the soil, Extremely cold winter air temperatures and high winds also contribute to the exclusion of trees.
Describe the soils of savannas
Poor soils and lack of moisture prevent the establishment of most trees.
How much rainfall do savannas get per year?
Rainfall averages 30-50 cm (about 12-20 inches) per year, almost all of it during a relatively brief rainy season.
What determines the vegetation growth in tropical rainforests?
Rainfall. Rainfall in these areas is quite variable, and this variability, rather than temperature or day length, determines the vegetation growth
How do organisms in the aphotic zones look like?
Some fishes in the twilight zone have enlarged eyes, enabling them to see in the very dim light, and luminescent organs that attract mates and prey.
Who lives in h benthic realm of the photic zone?
Sponges, burrowing worms, clams, sea anemones, crabs, and echinoderms
What are the two categories of freshwater biomes?
Standing water : lakes and ponds, and flowing water: rivers and streams.
What kind of bacteria extracts energy in hydrothermal vent communities?
Sulfur bacteria. Some of the animals there feed directly on the sulfur bacteria; others derive nutrition from bacteria living inside their bodies.
What is the benefit of wetlands?
They provide water storage areas that reduce flooding and improve water quality by filtering pollutants. Recognition of their ecological and economic value has led to government and private efforts to protect and restore wetlands.
describe the most complex biome
Tropical rainforests. Up to 300 species of trees can be found in a single hectare (2.5 acres). The forest structure consists of distinct layers that provide many different habitats: emergent trees growing above a closed upper canopy, one or two layers of lower trees, a shrub understory, and a sparse ground layer of herbaceous plants. Because of the closed canopy, little sunlight reaches the forest floor. Many trees are covered by woody vines growing toward the light. Other plants, including bromeliads and orchids, gain access to sunlight by growing on the branches or trunks of tall trees. Many of the animals also dwell in trees, where food is abundant. Monkeys, birds, insects, snakes, bats, and frogs find food and shelter many meters above the ground.
What provides coral with food?
Unicellular algae live within the corals, providing the coral with food
What is one thing that changed about the habitat of the pronghorn?
Until around 12,000 years ago the American cheetah was its predator. With natural selection the pronghorn became the fastest mammal with the speed of 97 km/hr (60 mph) while predators like wolves have a speed of 64 km/hr (40 mph)
What are scientists using to study climate change?
Using powerful tools such as satellite imagery, scientists are documenting shifts in latitudes of biome borders, changes in snow and ice coverage, and changes in length of the growing season.
What kind of vegetation do tundras have?
Vegetation in the tundra includes dwarf shrubs, grasses and other herbaceous plants, mosses, and lichens. During the brief, warm summers, when there is nearly constant daylight, plants grow quickly and flower in a rapid burst.
What distinguishes the nine major types of biomes?
Vegetation which is influenced by The climate, with temperature and precipitation often the key factors determining the kind of biome that exists in a particular region.
Why were we pollution ocean?
We thought it was a limitless resource
What organisms are found downstream a river?
Worms and insects that burrow into mud are often abundant, as are waterfowl, frogs, and catfish and other fishes that find food more by scent and taste than by sight.
coniferous Forest
a biome characterized by conifers, cone-bearing evergreen trees
Deserts
a biome characterized by organisms adapted to sparse and unpredictable rainfall and rapid evaporation (less than 30 cm/12 inches a year)
Savanna
a biome dominated by grasses and scattered trees and maintained by occasional fires and drought. The temperature is warm year-round.
Temperate broadleaf forest
a biome located throughout midlatitude regions where there is sufficient moisture to support the growth of large, broadleaf deciduous trees
estuary
a biome that occurs where a freshwater stream or river merges with the ocean.
What plants dominate temperate rainforests?
a few tree species, such as hemlock, Douglas fir, and redwood.
Population
a group of individuals of the same species living in a particular geographic area.
Organism
a living thing made up of cells.
Benthic realm
a seafloor, or the bottom of a freshwater lake, pond, river, or stream
interdital zone
a shallow zone where the water of an estuary or the ocean meets land.
Coral reefs
a visually spectacular and biologically diverse biome, are scattered around the globe in the photic zone of warm tropical waters above continental shelves
What is the average soil temperature in deserts?
above 60°C (140°F) and has large daily temperature fluctuations.
How are animals and plants in aquatic biomes distributed?
according to the depth of the water and its distance from shore. Examples: Phytoplankton live in the photic zone, and rooted plants often inhabit shallow waters near shore
What trees characterize temperate broadleaf forests?
deciduous trees (trees that drop their leaves seasonally)
Aquatic biomes
defined by different abiotic factors; the primary distinction is based on salinity.
The magnificent pronghorn "antelope"
descendant of ancestors that roamed the open plains and shrub deserts of North America more than a million years ago. The animal is found nowhere else and is only distantly related to the many species of antelope in Africa. The pronghorn's habitat is arid, windswept, and subject to extreme temperature fluctuations both daily and seasonally. Individuals able to survive and reproduce under these conditions left offspring that carried their alleles forward into subsequent generations. adaptations that helped this species survive are a thick coat made of hollow hairs that trap air, insulating the animal in cold weather. the pronghorn can raise patches of this stiff hair to release body heat.
Terrestrial biomes
determined primarily by temperature and precipitation—similar assemblages of plant and animal types are found in areas that have similar climates.
What does ecology describe?
distribution and abundance of organisms—where they live and how many live there.
Temperate grassland
dominated by grasses, trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less than in savannas. Temperate grasslands have hot summers and cold winters. Occur in South Africa, Hungary, Argentina, the steppes of the former Soviet Union, and the plains and prairies of central North America.
What do we depend on freshwater for?
drinking water, crop irrigation, sanitation, and industry.
Which area on earth absorbs the most heat?
equatorial areas.
Water
essential to all life.
Which aquatic biomes are most sensitive to pollution and why?
estuaries and wetlands because of their proximity to land. Many have been completely replaced by development on landfill.
Biosphere
extends from the atmosphere several kilometers above Earth to the depths of the oceans, is all of Earth that is inhabited by life. all ecosystems in earth.
Who lives in the aphotic zone?
fishes and crustaceans.
Where does the pronghorn get protection from?
from living in herds. When one pronghorn starts to run, its white rump patch seems to alert other herd members to danger. Other adaptations include its tan and white coat, which provides camouflage, and its keen eyes, which can detect movement at great distances. These adaptations were chosen by natural selection.
Solar energy's benefit?
helps drive the movements of water and air in global patterns. In addition, precipitation and evaporation, as well as transpiration (evaporative water loss from plants move water between the land, oceans, and atmosphere.
African savannas
home to giraffes, zebras, and many species of antelope, as well as to lions and cheetahs.
What are Some critical questions at the ecosystem level?
how chemicals cycle and how energy flows between organisms and their surroundings. For an alpine meadow, one ecosystem-level question would be, How rapidly does the decomposition of decaying plants release inorganic nutrients?
What would happen if the pronghorn's environment were to change significantly?
if an increase in rainfall turned the open plains into woodlands, where predators would be more easily hidden by vegetation and could stalk their prey at close range, the pronghorn's adaptations for escaping predators might not be as effective
Mojave Desert
in the rain shadow of the Sierra Nevada, along with much of the rest of Southern California and Nevada.
Marine biomes
include oceans, intertidal zones, coral reefs, and estuaries, generally have salt concentrations around 3%
What are The dominant herbivores in savannas?
insects, especially ants and termites. Also common are many burrowing animals, including mice, moles, gophers, snakes, ground squirrels, worms, and numerous arthropods.
Ecology
is the scientific study of the interactions between organisms and the environment.
Watertight coverings
key evolutionary adaptations enabling plants and vertebrates to be successful on land
Taiga
largest terrestrial biome on Earth northern coniferous forest in which the winters long and cold and summers are short and wet. Extend from north America and Eurasia to southern borders of the arctic tundra. Taiga is also found at cool, high elevations in more temperate latitudes, as in much of the mountainous region of western North America.
which plants and animals live in the polar ice
lichens and small plants, such as mosses, manage to survive, and invertebrates such as nematodes, mites, and wingless insects called springtails inhabit the frigid soil.
name a tropical rainforest
lush area on the island of Borneo
Prevailing winds
major global air movements. result from the combined effects of the rising and falling of air masses (blue and brown arrows) and Earth's rotation (gray arrows)
Biomes
major types of ecological associations that occupy broad geographic regions of land or water.
Who lives in the rocky intertidal zone and why?
many sedentary organisms, such as algae, barnacles, and mussels, which attach to rocks and thus resist being washed away when the tide comes in
Who is Rachel Carson?
marine biologist and writer with the U. S. Fish and Wildlife Service, compiled available evidence on the consequences of widespread pesticide use. Carson advocated a new approach to pest control that took the health of ecosystems into account.
What animals live in temperate broadleaf forests?
mice, shrews, and ground squirrels, burrow for shelter and food, while others, including many species of birds, live in the trees. Predators include bobcats, foxes, black bears, and mountain lions.
Where are chaparrals located?
middle latitudes about 30 degrees north and south of the equator- primarily in coastal areas that have mediterranean climates
Inorganic Nutrients
minerals and water
What animals live in taiga?
moose, elk, hares, bears, wolves, grouse, and migratory birds.
Where are savannas located?
near the equator
Where are tropical rainforests located?
near the equator
Where does photosynthesis occur in water?
near the surface
is all desert air dry?
no, Coastal sections of the Atacama and of the Namib Desert in Africa are often shrouded in fog, although the ground remains extremely dry.
are biomes self contained?
no, all parts of the biosphere are linked by the global water cycle and by nutrient cycles. events in one biome may reverberate throughout the biosphere.
What are some threats to aquatic biomes other than pollution?
nutrient pollution, contamination by pathogens or toxic chemicals, alteration of freshwater inflow, introduction of non-native species, and overfishing
What are the dominant trees in temperate broadleaf forests?
oak, hickory, birch, beech, and maple.
What limits growth in temperate grasslands?
periodic severe droughts and Fires and grazing by large mammals limit growth of woody plants but do not harm the below ground grass shoots.
What characterizes the arctic tundra
permafrost: continuously frozen ground (soil). only the upper part of the soil thaws (melts) in summer
what does The cycles of growth and reproduction in the desert depend on?
rainfall
How many inches/cm does it rain in tropical rainforests?
(200-400 cm, or 79-157 inches, per year).
Zooplankton
(animals that drift in aquatic environments), fish, marine mammals, and many other types of animals are abundant in the pelagic photic zone.
Fresh water biomes
(lakes, streams and rivers, and wetlands) typically have a salt concentration of less than 1%.
Who provides energy and organic carbon for organisms in the ocean?
(microscopic algae and cyanobacteria) and multicellular algae provides energy and organic carbon for a diverse community of animals by photosynthesis on the pelagic zone.
Wetland
A land area that is covered with a shallow layer of water during some or all of the year. constitute a biome that is transitional between an aquatic ecosystem—either marine or freshwater—and a terrestrial one.
What is the difference between tropical rainforest and temperate rainforest?
A main different between tropical rainforests and temperate rainforest is climate. Tropical rainforests are moist and very warm all year round. Temperate rainforest are cool in the winter and warm in the summer. Another difference between tropical rainforests and temperate rainforests are types of trees.
Describe streams and rivers?
A river or a stream changes lot between its beginning (a spring or snowmelt) and the point at which it empties into a lake or the ocean. Near the beginning, the water is clear, cold, and oxygen-rich, with a swift current that supports the growth of phytoplankton Most of the organisms found here are supported by the photosynthesis of algae attached to rocks or by organic material, such as leaves, carried into the stream from the surrounding land.
tropical forests
A terrestrial biome characterized by high levels of precipitation and warm temperatures year-round.
Polar ice
A terrestrial biome that includes regions of extremely cold temperature and low precipitation located at high latitudes north of the arctic tundra and in Antarctica. much of the Arctic Ocean is continuously frozen as well. In the Southern Hemisphere, polar ice covers the continent of Antarctica which is surrounded by a ring of sea ice, and numerous islands. Only a small portion of these landmasses is free of ice or snow, even during the summer.
What is the effect of landforms on local climate?
Air temperature declines by about 6°C with every 1,000-m increase in elevation, an effect you've probably experienced if you've ever hiked up a mountain. This drawing represents major landforms across the state of California, but mountain ranges cause similar effects elsewhere. California is a temperate area in which the prevailing winds are westerlies. As moist air moves in off the Pacific Ocean and encounters the westernmost mountains (the Coast Range), it flows upward, cools at higher altitudes, and drops a large amount of water. The world's tallest trees, the coastal redwoods, thrive here. Farther inland, precipitation increases again as the air moves up and over higher mountains (the Sierra Nevada). Some of the world's deepest snowpacks occur here. On the eastern side of the Sierra, there is little precipitation, and the dry descending air also absorbs moisture. This effect, called a rain shadow, is responsible for the desert that covers much of central Nevada, for example, as well as other deserts located inland from coastal mountain ranges.
Community
All the different populations that live together in an area. all of the biotic factors in the environment.
Tundra
An extremely cold, dry biome. covers expansive areas of the Arctic between the taiga and polar ice
Twighlight zone
Aphotic zone
How might a scientist investigate the ecology of an alpine meadow high in the Himalayan mountains? (examples of all levels)
At the organism level, they may examine how one kind of organism meets the challenges and opportunities of its environment through its physiology or behavior. For example, an ecologist working at this level might study adaptations of the Himalayan blue poppy to the freezing temperatures and short days of its abiotic environment. An ecologist studying blue poppies might investigate factors that affect the size of the population, such as the availability of chemical nutrients or seed dispersal. An ecologist working at community level might focus on interspecies interactions, such as the effect of plant-eaters on poppies or the competition between poppies and other plants for soil nutrients. Himalayan alpine meadows are part of a mountain landscape that also includes conifer and broadleaf forests. A landscape perspective emphasizes the absence of clearly defined ecosystem boundaries; energy, matter, and organisms may be exchanged by ecosystems within a landscape.
Wind blowing directions
Because Earth is spherical, its surface moves faster at the equator, where its diameter is greatest, than at other latitudes. In the tropics, Earth's rapidly moving surface deflects vertically circulating air, making the trade winds blow from east to west. In temperate zones, the slower-moving surface produces the westerlies, winds that blow from west to east.C
What is each biome characterized by other than vegetation?
Biological communities. For example, the species living in the deserts of the American Southwest and in the Sahara Desert of Africa are different, but all are adapted to desert conditions. Widely separated biomes may look alike because of convergent evolution: the appearance of similar traits in independently evolved species living in similar environments
What are the two major factors in ecology?
Biotic and abiotic
What are the adaptations of vegetations in chaparrals?
Chaparral vegetation is adapted to periodic fires, most often caused by lightning. Many plants contain flammable chemicals and burn fiercely, especially where dead brush has accumulated for some time. After a fire, shrubs use food reserves stored in the surviving roots to support rapid shoot regeneration. Some chaparral plant species produce seeds that will grow only after exposure to a hot fire. The ashes of burned vegetation fertilize the soil with mineral nutrients, promoting regrowth of the plant community.
Explain the case with DDT in the 1950's
DDT was an insecticide that was employed against crop pests and disease-carrying insects such as mosquitoes body lice, and fleas. Consumers complained about chemical residues in their food. farmers found their milk contaminated by aerial spraying on nearby crops. Fish and wildlife experts, along with private citizens, saw dozens of birds, fish, and other mammals poisoned. some of scientists found that small amounts of pesticides had accumulated in the fatty tissues of vertebrates thousands of miles from where pesticides were used. DDT was even detected in human milk. Scientists found that DDT stayed in the soil or water long after application of the pesticide. one study correlated bird deaths on a university campus with DDT sprayed in previous years. birds consumed a toxic dose of the poison when they ate earthworms that had fed on DDT-contaminated leaves decaying in the soil. Other scientists reported similar correlations between the use of DDT and animals in aquatic ecosystems as well as in other terrestrial ecosystems. Birds of prey seemed to be especially vulnerable
Australian savannas?
Dominated by kangaroos
Wetlands
Ecosystems of several types in which vegetation is surrounded by stand water during part of the year includes marshes, bogs, and swamps. WHAT ARE YOU DOING IN MY SWAMP
Describe the soil in temperate grassland
Enriched by glacial deposits and mulch from decaying plant material, the soil of grasslands supports a great diversity of microorganisms and small animals, including annelids and arthropods.
Where does sunlight strike earth most directly (perpendicularly)?
Equatorial areas
What provides food for organisms living in aphotic zones?
Food sinking from the photic zone. In addition, many of them migrate to the surface at night to feed
How much does freshwater biomes cover from the earth's surface?
Freshwater biomes cover less than 1% of Earth's surface and contain a mere 0.01% of its water.
Where does the aphotic zone where light levels are too low to support photosynthesis form?
If a lake or pond is deep enough or murky enough
How uneven heating causes rain and winds
High temperatures in the tropics evaporate water from Earth's surface and cause warm, moist air masses to rise and flow toward the poles. As the rising air cools, its ability to hold moisture diminishes. The water vapor condenses into clouds and rain falls. High temperatures throughout the year and ample rainfall largely explain why rain forests are concentrated near the equator. After losing their moisture over equatorial zones, high-altitude air masses spread away in two opposing directions from the equator until they cool and descend again at latitudes of about 30° north and south. This descending dry air absorbs moisture from the land. Thus, many of the world's great deserts—the Sahara in North Africa and the Arabian on the Arabian Peninsula, for example—are centered at these latitudes. As the dry air descends, some of it spreads back toward the equator. This movement creates the cooling trade winds, which dominate the tropics. As the air moves back toward the equator, it warms and picks up moisture until it ascends again.
alpine tundra
High winds and cold temperatures create plant communities called alpine tundra on very high mountaintops at all latitudes, including the tropics Although these communities are similar to arctic tundra, there is no permafrost beneath alpine tundra
Where do birds nest in temperate grassland
In the absence of trees, many birds nest on the ground, and some small mammals dig burrows to escape predators.
Describe the environment in the benthic zone?
In the benthic realm, large populations of microorganisms decompose dead organisms that sink to the bottom. Respiration by microbes removes oxygen from water near the bottom, and in some lakes, benthic areas are unsuitable for any organisms except anaerobic microbes.
Eutrophication
Many lakes and ponds receive large inputs of nitrogen and phosphorus from sewage and runoff from fertilized lawns and farms. These nutrients may produce a heavy growth ("bloom") of algae, which reduces light penetration. When the algae die and decompose, a pond or lake can suffer severe oxygen depletion, killing fish that are adapted to high-oxygen conditions.
Describe the adaptations of vegetations in deserts?
Many live in burrows and are active only at night, when temperatures drop, and most have special adaptations that conserve water. Seed-eaters such as ants, many birds, and rodents are common in deserts. Lizards, snakes, and hawks eat the seed-eaters.
Abiotic factors
Nonliving components of environment.
what are some ways vegetations in savannas are adapting to drought?
Savanna plants have also been selected for their ability to survive prolonged periods of drought. Many trees and shrubs are deciduous, dropping their leaves during the dry season, an adaptation that helps conserve water.
Describe temperate broadleaf forests' climate and precipitation
Temperatures vary seasonally with hot summers and cold winters. Annual precipitation is high at 75-150 cm (30-60 inches) and is evenly distributed throughout the year as either rain or snow. They have a growing season of five to six months and a distinct annual rhythm. Trees drop their leaves in late autumn, preventing the loss of water from the tree at a time when frozen soil makes water less available. The trees produce new leaves in the spring.
what influences the height of grassland vegetation in temperate grasslands?
The amount of annual precipitation. hortgrass prairie is found in relatively dry regions; tallgrass prairie occurs in wetter areas. Little remains of North American prairies today. Most of the region is intensively farmed, and it is one of the most productive agricultural regions in the world.
Describe the precipitation in tundras
The arctic tundra may receive as little precipitation as some deserts. But poor drainage, due to the permafrost, and slow evaporation keep the soil continually saturated.
Compare and contrast between tropical rainforest and temperate broadleaf forests?
The canopy of a temperate broadleaf forest is more open than that of a tropical rain forest, and the trees are not as tall or as diverse. However, the soils are richer in inorganic and organic nutrients. Rates of decomposition are lower in temperate forests than in the tropics, and a thick layer of leaf litter on forest floors conserves many of the biome's nutrients.
Describe the climate of tundras
The climate here is often extremely cold, with little light for much of the autumn and winter.
Describe the climate of chapparals
The climate that supports chaparral vegetation results mainly from cool ocean currents circulating offshore, which produce mild, rainy winters and hot, dry summers. As a result, this biome is limited to small coastal areas, including California,
what protects the conifers' branches from heavy snow?
The conical shape of many conifers prevents too much snow from accumulating on their branches and breaking them.
How are aquatic biomes different?
The deepest ocean, where hydrothermal vents are located, is perpetually dark. In contrast, the vivid coral reefs are utterly dependent on sunlight. Habitats near shore are different from those in mid-ocean, and the substrate, which varies with depth and distance from shore, hosts different communities from the open waters.
Photic realm
The depth of light penetration, a maximum of 200 m (656 feet)
Which biome is the most effective biome on earth and why?
The estuary biome because: 1- The saltiness of estuaries ranges, across their length, from nearly that of fresh water to that of the ocean. 2- their waters enriched by nutrients from a river 3- Oysters, crabs, and many fishes live in estuaries or reproduce in them. Estuaries are also crucial nesting and feeding areas for waterfowl.
What is the second driest place on earth?
The large deserts in central Australia and northern Africa have average annual rainfalls of less than 2 cm
What is the difference between tropical forest and tropical rainforests?
The main difference between a temperate rainforest and tropical rainforest is location. Tropical rainforests are located near the equator between the Tropics of Cancer and Capricorn. Temperate rainforests are located to the north of the Tropic of Cancer and to the south of the Tropic of Capricorn.
What determine the amount of phytoplankton growth in a lake or pond?
The mineral nutrients nitrogen and phosphorus.
What is the most abundant benthic animals in rivers and streams?
The most abundant benthic animals are usually arthropods, such as small crustaceans and insect larvae, that have physical and behavioral adaptations that enable them to resist being swept away. Trout, which locate their insect prey mainly by sight in the clear water, are often the predominant fishes.
How does The biotic environment, which includes what the animal eats and any predators that threaten it, is a factor in determining which members of a population survive and reproduce?
The pronghorn's main foods are small broadleaf plants, grasses, and woody shrubs. As a result, the teeth of a pronghorn are specialized for biting and chewing tough plant material. Like the stomach of a cow, the pronghorn's stomach contains cellulose-digesting bacteria. As the pronghorn eats plants, the bacteria digest the cellulose, and the animal obtains most of its nutrients from the bacteria.
what are two possible explanations The presence of a species in a particular place has?
The species may have evolved from ancestors living in that location, or it may have dispersed to that location and been able to survive once it arrived.
How long are giant tube worms?
These worms can grow to be over 2 m (6.5 feet) long.
Ecosystem
both the biotic and abiotic components of the environment
What does the photic zone include?
both the pelagic and benthic realms
What animals live in the chaparrals?
browsers such as deer, fruit-eating birds, and seed-eating rodents, as well as lizards and snakes.
How do animals withstand the cold of the tundra?
by having good insulation that retains heat.
Where are deserts located?
centered around the 30° north and 30° south latitudes. At higher latitudes, large deserts may occur in the rain shadows of mountains. these encompass much of central Asia east of the Caucasus Mountains, and Washington and Oregon east of the Cascade Mountains.
hat determines whether a particular organism or community of organisms lives in a certain area?
climate
Temperate rainforest
of coastal North America (from Alaska to Oregon) are also coniferous forests. Warm, moist air from the Pacific Ocean supports this unique biome. These forests are heavily logged, and the old-growth stands of trees may soon disappear.
Other Aquatic Factors
oxygen dissolved in water. Cold, fast-moving water has a higher oxygen content than warm or stagnant water. Salinity, current, and tides may also play a role in aquatic ecosystems.
Name realms in the ocean?
pelagic, benthic, photic
Ocean currents
river-like flow patterns at the oceans' surface
Landscape
several different ecosystems linked by exchanges of energy, materials, and organisms. Landscapes are usually visible from the air as distinctive patches
How is a reef built?
slowly by successive generations of coral animals—a diverse group of cnidarians that secrete a hard external skeleton—and by multicellular algae encrusted with calcium carbonate.
What is the benefit of coral reefs?
support a huge variety of invertebrates and fishes.
who lives on sandy beaches?
suspension-feeding worms, clams, and predatory crustaceans bury themselves in the ground.
What temperatures destroy the enzymes of most organisms?
temperatures above 45°C (113°F)
what does The mix of tree species vary on in temperate broadleaf forests?
the climate at different latitudes, topography, and local soil conditions.
Desertification
the conversion of semi-arid regions to desert. a significant environmental problem. In northern Africa, for example, a burgeoning human population, overgrazing, and dryland farming are converting large areas of savanna to desert.
Describe the vegetations in deserts?
the driest deserts have no vegetation. Less arid deserts have scattered deep-rooted shrubs, often interspersed with water-storing succulents such as cacti. The leaves of some plants (the Joshua tree) have a waxy coating that prevents water loss. Desert plants produce lots of seeds, which may remain ungrown until a heavy rain grows them. After lots of rainfall, often in late winter, annual plants in deserts start to bloom.
What determines Earth's global climate patterns?
the input of radiant energy from the sun and the planet's movement in space.
what gives the vegetation a patchy, rather than uniform, appearance?
the local variation within each biome. For example: in northern coniferous forests, snowfall may break branches and small trees, causing openings where broadleaf trees such as aspen and birch can grow. Local disturbances such as storms and fires also create openings in many biomes.
landforms
the natural features of the land's surface
Describe the ocean Below 1,000 m?
the ocean is completely and permanently dark. Adaptation to this environment has produced bizarre-looking creatures, such as the angler fish. The scarcity of food causes the outsized mouths of the angler and other fishes that live in this region, and it allows them to grab any available prey, large or small. Inwardly angled teeth ensure that once caught, prey do not escape. The angler fish improves its chances of encountering prey by dangling a lure lit by bioluminescent bacteria. Most benthic organisms here are deposit feeders, animals that consume dead organic matter (detritus) on the substrate. Crustaceans, annelid worms, sea anemones, and echinoderms such as sea cucumbers, sea stars, and sea urchins are common. Because of the scarcity of food, however, the density of animals is low—except at hydrothermal vents, where chemoautotrophic bacteria support an abundance of life
What happens to a river in the downstream?
widens and slows. The water is usually warmer, lower in oxygen, and may be murkier because of sediments and phytoplankton suspended in it.
Other Terrestrial Factors
wind, storms, fire
What are some consequences of dumping waste in the ocean?
worldwide declines in commercial fish species and dying coral reefs to beaches
Can deserts be cold?
yes, those west of the Rocky Mountains, are relatively cold. Air temperatures in cold deserts may fall below −30∘C(−22∘F)−30∘C (−22∘F).