Intro to Ecology

What happens to animal and plant diversity as latitude decreases?

Animal and plant diversity increases.

Which level of ecological study focuses the most on abiotic factors?

ecosystem ecology Students must first know what abiotic factors are and then link them to the area of study using these factors the most in research.

How might global warming impact terrestrial biomes?

increased variability in temperature and precipitation Increased evaporation from oceans can increase precipitation in certain areas.

A(n) _____ is a region where fresh water and salt water mix.

estuary

In deep water, which of the following abiotic factors would most limit productivity? a. light availability b. solute concentration c. temperature d. all of the above

light availability

biomes

regions characterized by distinct abiotic characteristics and dominant types of vegetation

range

geographic distribution of organisms

Which biome is the most productive?

tropical wet forest

The nature of the terrestrial biome that develops in a particular region is determined by (1) _______ and (2) _____

(1) average annual temperature and precipitation (2) annual variation in temperature and precipitation. Each biome contains species that are adapted to a particular temperature and moisture regime.

Major themes of ecology

- Behavior - Life history strategies and population dynamics - Interactions between individuals and species, community structure. - Ecosystem dynamics, biogeochemistry

Why are natural lakes and ponds more common at higher latitudes?

Because melting glaciers leave large chunks of ice or piles of geological debris

NPP

Biologists are particularly concerned with how temperature and moisture influence net primary productivity (NPP). NPP is defined as the total amount of carbon that is fixed per year minus that amount that is oxidized during cellular respiration. Fixed carbon that is oxidized in cellular respiration releases energy for the organism but is not used for growth - (put towards their biomass). NPP = GPP - respiration Consumers depend on NPP. NPP represents the resource for the base of the community. NPP is crucial because it represents the organic matter that is available as food for other organisms. IN terrestrial environments, NPP is often estimated by measuring aboveground biomass

Global Ecology

Biosphere - a thin zone surrounding the Earth where all life exists - the sum of all terrestrial and aquatic ecosystems. It extends to about 5 km below the land surface and 10 km down in the deepest trenches of the sea to over 10 km up into the atmosphere. This is only about 0.002 percent of the diameter of the Earth - an most life occupies a much thinner layer. Global ecology is growing rapidly as ecologist scramble to quantify the effects of human impacts on the biosphere. Humans are modifying landscapes and releasing massive amounts of energy and nutrients to the biosphere, causing changes that transcend individual ecosystems. Since the biosphere is practically a closed system, the actions of people in one part of the world may alter distant ecosystems. Example: Salmon are sensitive to changes to temperature in water which is a cause of climate change.

What is the main difference between climate and weather?

Climate typically describes longer-term conditions.

Why are fish found in cold, fast-moving streams more active than those in warm, slow-moving streams?

Cold, fast-moving areas are rich in oxygen

Community Ecology

Community ecologists ask questions about the nature of the interactions between species and the consequences of those interactions. Research right concentrate on predator, parasitism, and competition or explore how communities respond to fires, floods, and other disturbances. Example: Consider the interactions among salmon and other species in the marine and stream communities where they live. When they are at sea, salmon eat smaller fish and are themselves hunted and eaten by orcas, sea lions, humans, and other mammals; when they return to freshwater to breed, they are preyed on by bears and bald eagles. In both marine and freshwater habitats, salmon are subject to parasitism and disease. They are also heavily affected by disturbances - particularly changes in their food supply and the quality of their breeding streams. (community - consists of populations of different species that interact with each other within a particular area)

Benthic zone for oceans

bottom of the ocean

When do lake turnovers occur?

When water on top of the lake is denser than water below Lake turnover occurs in spring and fall in response to changes in air temperature causing dense, cold water to sink to the bottom.

Spring and fall lake turnovers occur in response to _____.

changes in air temperature

Contrast the productivities of the intertidal, neritic, and oceanic zones of marine environments. Explain why large differences in productivity exist: The deepest part of the oceanic zone may have nutrients _____ but lacks light to _____

available from the substrate; support photosynthesis

Water at the source of a stream has which of the following characteristics? a. High nutrient levels b. High oxygen levels c. Slow movement d. High temperature

b. High oxygen levels The water at the source of a stream generally has high oxygen levels because water droplets are exposed to the atmosphere when fast-flowing water splashes over rocks.

Which zone is found only in freshwater environments? a. Benthic zone b. Littoral zone c. Neritic zone d. Aphotic zone

b. Littoral zone

Besides sunlight, which would be the next most important climatic factors for plants? a. wind and fire b. temperature and moisture c. temperature and wind d. moisture and wind

b. temperature and moisture

For a species to be called "invasive," it must _____.

be introduced to a new area, spread rapidly in this area, and eliminate native species

Which freshwater environment is characterized by low pH, lack of nitrogen, and anoxic conditions, making it relatively unproductive?

bog

turbidity

cloudiness

___ and ecology are intertwined and codependent

evolution

Neritic zone

extends from the intertidal zone to the depths of about 200 m. Its outermost edge is defined by the end of the continental shelf

aboveground biomass

the total mass of living plants, excluding roots.

benthic zone

occurs that the substrate (material that rests at the bottom)

North Georgia has what ind of terrestrial biome?

temperate deciduous

aphotic zone

Portions of the lake that do not receive sunlight.

Exotic Species

species that is not native to the area

Ecology's primary goal is to ______

understand the distribution and abundance of organisms

Which abiotic factor would have the most significant physiological effect on migrating salmon? a. ambient temperature b. human-built structural interferences c. competition for resources d. water solute content

water solute content Students must first know what abiotic factors are and then link them to migrating salmon. They must also know that although water temperatures can change during migration, it is the water solute content (salinity) that changes more and significantly affects salmon physiology.

5 Major Aquatic Biomes

1. Freshwater - Lakes and Ponds 2. Freshwater - Wetlands 3. Freshwater - Streams 4. Freshwater/Marine - Estuaries 5. Marine - Oceans

Five main levels of ecology that researchers study ecology at

1. Organismal Ecology 2. Population Ecology 3. Community Ecology 4. Ecosystem Ecology 5. Global/Biosphere Ecology

4 Major abiotic factors that distinguish streams from oceans

1. Salinity 2. Water Depth 3. Water Flow 4. Nutrient Availability

Natural Biomes

Different ecosystems may belong to the same biome. For example, the Sonoran Desert in North America and the Sahara Desert in Africa are both apart of the same biome - subtropical desert - but each is a unique ecosystem with its own community of indigenous organisms. Biomes: - Tropical wet forest - Subtropical wet forest - Temperate grassland - Temperate forests - Boreal forest - Arctic tundra

How are Aquatic Biomes affected by Humans?

Direct Effects - Humans cause physical changes to aquatic ecosystems by filling or draining wetlands, damming streams, and removing water from ponds and rivers for agricultural irrigation. Humans also cause biological changes by transporting organisms - such as the invasive zebra mussel, which has become a scourge in the Great Lakes of North America and other regions of the world - and overexploiting marine resources, especially top predators such as tuna and sharks, causing cascading effects on food webs Indirect Effects -Global climate changes influence aquatic ecosystems by the same mechanisms for terrestrial ecosystems. In addition, increased atmospheric CO2 is causing waterways to become more acidic, limiting the ability of organisms like corals to build skeletons, and having other far-reaching effects.

Four Components of climate

Each of the terrestrial biomes found around he world is associated with a distinctive set of abiotic conditions determined largely by climate: - Temperature is critical because the enzymes that make life possible work at optimal efficiency only in a narrow range of temperatures. Temperature also affects the availability of moisture: Water freezes at low temperatures and evaporates rapidly at high temperatures. - Moisture is significant because it is required for life, and because terrestrial organisms constantly lose water to the environment through evaporation or transpiration. To stay alive, they must reduce water loss and replace lost water - Sunlight is essential because it is required for photosynthesis - Wind is important because it makes the effects of temperature and moisture worse. Wind increases heat loss due to evaporation and convection, and it increases water loss due to evaporation and transpiration. Wind also has a direct physical impact on organisms such as birds, flying insects, and plants - it pushes them around. Of the four components of climate, variation in temperature and moisture are far and away the moist important in determining plant distribution and abundance.

Ecosystem Ecology

Ecosystem ecology is an extension of organismal, population, and community ecology. An ecosystem consists of all the organisms in a particular region along with nonliving components. These physical and chemical, or abiotic (non-living), components include air, water, and the non-living parts of soil. At the ecosystem level, biologists study how nutrients and energy move among organisms and through the surrounding atmosphere and soil or water. Example: Salmon link marine and freshwater ecosystems. They harvest nutrients in the ocean and then, when they migrate, die, and decompose, they transport those molecules to streams and streamed forests. In this way, salmon transport chemical energy and nutrients from one habitat to another.

Aquatic Biomes: Freshwater/Marine - Estuaries

Estuaries form where rivers meet oceans - meaning that freshwater mixes with salt water. An estuary includes saline marshes (from slightly to high saline) as well as the body of water that moves in and out of these environments. Salinity varies with (1) changes in river flows - it declines with the river floods and increases when the river recedes - and (2) with proximity to the ocean. Species that live in estuaries have physiological adaptions that allow them to cope with variations in salinity. Water depth - Most estuaries are shallow enough that sunlight reaches the substrate. Water depth may fluctuate dramatically, however, in response to tides, storms, and floods Water flow and nutrient availability - Water flow in estuaries fluctuates daily and seasonally due to tides, storms, and floods. Estuaries are nutrient rich because nutrient-laden sediments are deposited when the flowing river water slows as it enters the ocean Organisms - Because the water is shallow and sunlit, and because nutrients are constantly replenished by incoming river water, estuaries are among the most productive environments on Earth. They serve as a nursery for young fish, which feed on abundant vegetation, benthic invertebrates, and plankton while hiding from predators. Estuaries also tend to have high species diversity. Estuaries are also important feeding grounds for both residential and seasonal bird populations.

GPP

Gross Primary Production. In an ecosystem, the total amount of carbon fixed by photosynthesis (or more rarely, chemosynthesis), including that used for cellular respiration, over a given time period.

The influence of Humans

Humans have influences the distribution of species for thousands of years by hunting, clearing forests, and physically moving organisms around. Humans have transported thousands of plants, birds, insects, and other species across physical barriers to new locations - sometimes purposefully and sometimes by accident. Microorganisms that humans introduce to new areas can also dramatically affect species distributions by causing disease. Humans continue to influence the distribution of species by affecting both biotic and abiotic factors.

ocean upwelling

In oceans, nutrients in the sunlit surface waters are constantly lot in the form of dead organisms that rain down into the depths. In certain coastal regions of the world's oceans, however, nutrients are brought up to the surface by currents that cause upwellings. Prevailing winds blow along the coastline, pushing surface water to the north. Because the Earth rotates constantly, this wind-driven water current is slowly moved offshore. As the surface water moves away from the coast, it is steadily replaced by water moving up from the ocean bottom. The upwelling water is nutrient rich. In effect, it recycles nutrients that earlier had fallen to the ocean floor.

How will global climate change affect terrestrial biomes?

It is now well established that human-caused emissions of greenhouse gases like Co2 are causing climate change. Climate has change frequently and radically throughout the history of life, but recent increases in average temperatures around the globe, combines with a projected increase of up to 5.8 degrees C over the next 100 years, represent one of the most Biologists are using four tools to make predictions for global climate change affecting the overall distribution of life on Earth 1. Simulation studies - based on computer models of weather patterns in local regions. 2. Observational studies - based on long term monitoring at fixed sites around the globe 3. Historical Studies - examine the relationship between CO2 levels, climate change, and the distribution and abundance of organisms during events the occurred millions of years ago. 4. Experiments - designed to stimulate changed climate conditions and to record response by the organisms present In an analysis of data from 11 stud sites scattered throughout the arctic, several strong patterns emerged: - Overall, species diversity decreases - Compared with control plots, grasses and shrubs increase inside the chambers, and mosses and lichens decrease. These experimental results support simulations and observational studies prediction that arctic tundra environments are giving way to boreal forest. Scientist also predict that rapid change will cause the Amazon to change from a forested stable state to a grassland stable state with dramatic effects on biodiversity. Other simulation and observational studies have converged on a remarkable conclusion: Increases in average global temperature are increasing variably in temperature and precipitation. Stated another way, global climate change is making climates more extreme. Average temperature and average annual precipitation in many regions may not be changing, even though variation is. For example, thus far the frequency of monsoons rains, cyclones, hurricanes, and other types of storm events is not changing. However, the amount of precipitation and the wind speeds associated with these events are increasing. The severity of droughts is also on the rise.

Aquatic Biomes: Freshwater - Lakes and Ponds

Lakes and ponds are distinguished from each other by size. Ponds are small; lakes are large enough that the water can be mixed by wind and wave action. Most natural lakes and ponds occur in high latitudes - they form in depressions created by scouring action of glaciers thousands of years ago. Water Depth - Biologists describe the structure of lakes and ponds by naming zones, some of which overlap - Littoral "seashore" zone - consists of the shallow waters along the shore, where flowering plants are rooted - Limnetic "lake" zone - is offshore and consists of water that receives enough light to support photosynthesis - Benthic "depths" zone - occurs that the substrate (material that rests at the bottom) - Photic zone - consists of the littoral, limnetic, and benthic zones that receive sunlight - Aphotic - Portions of the lake that do not receive sunlight. Water flow and nutrient availability - Water movement is driven by temperature and wind. Littoral and Limnetic zones are typically warmer and better oxygenated than the benthic zone, but the benthic zone is relatively nutrient rich because dead decomposing bodies sink and accumulate there. Movement of nutrients depends on turnovers Organisms - Cyanobacteria, algae, and other microscopic organisms, collectively called plankton, live in the photic zone, and do the fish and small crustaceans - organisms related to shrimp and crabs - that eat them. In shallow parts of the photic zone, rooted plants are common. Animals (invertebrates and fish) that consume dead organic matter, or detritus, are abundant in benthic zone

Abiotic Factors

No one species can survive the full array of environmental conditions present on Earth. Temperatyre is particularly important in determining ranges because temperature has a big impact on the physiology of organisms, and organisms are limited in their abilityy to regulate their own temperatures. Because of fitness trade-offs, organisms tend to be adapted to a limited set of physical conditions, or abiotic factors - for example, to a particular temperature and moisture regime on land, or a particular salinity, water depth, and movement regime in water. Every organisms has a specific range of tolerance or abiotic conditions

Aquatic Biomes: Marine - Oceans

Oceans form a continuous body of salt water and are remarkably uniform in chemical composition. Regions within an ocean vary markedly in their physical characteristics however, and have profound effects on the organisms found there Water depth - Biologist describe the structure of oceans by naming zones - Intertidal "between tides" zone - consist of a rocky, sandy, or muddy beach that is exposed to the air at low tide but submerged at high tide - Neritic zone - extends from the intertidal zone to the depths of about 200 m. Its outermost edge is defined by the end of the continental shelf (gently sloping, submerged portion of a continental plate) - Oceanic zone - the "open ocean" - the deep-water region beyond the continental shelf - Benthic zone - bottom of the ocean - Photic zone - The intertidal and sunlit regions of the neurotic, oceanic, and benthic zones - Aphotic zone - areas that do not receive sunlight The ocean is very deep (average depth 3.7 km), but its depth is small compared to tis breadth. Water flow and nutrient availability - Water movement in the ocean is dominated by different process at different depths. In the intertidal zone, tides and wave action are the major influences. In the neritic zone, currents that bring nutrient-rich water from the benthic zone of the deep ocean towards shore have a heavy impact. Throughout the ocean, large-scale currents circulate water in the oceanic zone in response to prevailing winds and the Earth's rotation (upwelling). In general, nutrient availability is dictate by water movement. The neritic and intertidal zones are relatively nutrient rich because they receive nutrients from rivers and upwelling. The oceanic zone, in contrast, constantly loses nutrients due to a steady rain of dead organisms drifting to the benthic zone (bottom of the ocean). Organisms - each zone in the ocean is populated by distinct species that are adapted to the physical conditions present. [Look at study sheet for more details.]

Theoretically, which would be the most effective way to disrupt a Hadley cell?

Remove all equatorial moisture and convection. Theoretically, shifting the Suns direct rays would keep the Hadley cell operational, but if you remove equatorial land-locked moisture, you could disrupt the portion of the cell that keeps the equatorial areas moist.

Organismal Ecology

Researchers explore the morphological physiological (functions of body parts), and behavioral adaptions that allow individuals to live in a particular area. Example: After spending four or five years feeding and growing in the ocean, sockeye salmon travel hundreds or thousands of kilometers to return to the stream where the hatched. Females create nests in the gravel stream bottom and lay eggs. Nearby males compete for the chance to fertilize eggs as they are laid. When breeding is finished, all the adults die.

What causes seasonality in weather?

Seasons (regular, annual fluctuations in temperature, precipitation, or both) occur because Earth is tilted on its axis by 23.5 degrees. As a result of this incline, the Northern Hemisphere is tilted toward the sun in June. In this position, it faces the Sun most directly. In June, the Northern Hemisphere presents its least acute angle to the Sun and receives the largest amount of solar radiation per unit capita. The Southern Hemisphere, in contrast, is tilted away from the sun in June. As a result, it presents a steep angle for incoming sunlight and receives its smallest quantity of solar radiation per unit area. So, in June it is summer in the Northern Hemisphere and winter in the Souther hemisphere. Conversely, in December it is summer in the Southern Hemisphere and winter in the Northern Hemisphere. In March and September, the equator faces the Sun most directly. During these months, the tropics receive the most solar radiation. If Earth did not tilt on its axis, there would be no seasons!

Organisms in the aphotic zone are often missing which sense?

Sight

Aquatic Biomes: Freshwater - Streams

Streams are bodies of water that move constantly in one direction. Creeks are small streams rivers are large streams Water depth - Most streams are shallow enough that sunlight reaches the bottom. Availability of sunlight is usually not a limiting factor for organisms, except with turbidity is high. Water flow and nutrient availability - The structure of a typical stream varies in length. Where it originates at a mountain glacier, lake, or spring, a stream tends to be cold, narrow, and fast. As it descends toward a lake, ocean, or larger river, a stream accepts water from tributaries and becomes larger, warmer, and slower. Oxygen levels tend to be high in fast-moving, cold streams. Slow moving streams tend to be more nutrient rich, because decaying matter does not flush away as quickly. Organisms - It is rare to find photosynthetic organisms in small, fast-moving streams; nutrient levels tend to be low, and most of the organic mater present consists of leaves and other materials that fall into the water from outside of the stream. Fish, insect larvae, mollusks, and other animals have adaptations that allow them to maintain their positions in the fast moving portions of the streams. As streams widen and slow down, conditions become more favorable for the growth of algae and plants, and the amount of organic matter and nutrients increases.

Terrestrial Biomes: Temperate Forests

Temperate forests in North America and Europe are dominated by deciduous species, which are leafless in winter and grow new leaves each spring and summer. Needle-leaved evergreens are also common. Most temperate forests have productivity levels lower than those of tropic forests yet higher than those of deserts or grasslands. The level of diversity is also moderate. Temperate forests have moderate productivity simply because temperatures do not support photosynthesis year-round. temperature - temperate forests experience moderate fluctuations in mean monthly temperatures, sometimes falling below freezing, as in the Chicago area precipitation - precipitation is moderate, and relatively constant throughout the year compared to grassland climates; average annual precipitation in the Chicago area is 85 cm, exceeding 5 cm during most months.

If the Earth were to reorient such that the North Pole always received direct sunlight (always faced the Sun), how would that change Earth's climate?

The South Pole would get colder.

Biotic Factors

The ability of a species to persist in a given area is often limited by biotic ("living") factors - meaning interactions with other organisms. Example: Let's consider the distribution of hermit warblers and Townsend's warblers along the Pacific Coast of North America - Both hermit warblers and Townsend's warblers live in ever green forests - Experiments have shown that male Townsend's warblers directly attack able hermit warblers and evict them from breeding territories - The geographic range of Townsend's warblers has been expanding steadily at the expense of hermit warblers. These observations support the hypothesis that a biotic factors - competition with another species - is limiting the range of hermit warblers. Competition is not the only biotic factor to affect species range, however. - Yucca moths lay their eggs only in the flowers of yucca plants. As a result, this species does not exist outside the range of yucca plants - In Africa, the range of domestic cattle is limited by the distribution of tsetse flies. Tsetse flies transmit a parasite that causes the diseases trypanosomiasis, which is fatal in cattle - Most of the songbirds native to Hawaii are limited to alpine habitats - above the range of the mosquitoes that transmit avian malaria. The distribution of organisms is determined not only by conditions present today but also by events in the past.

Past Abiotic and Biotic Factors Influence Present Patterns

The abiotic and biotic factors that influence the distribution of organisms are dynamic - they are constantly changing, in part because the Earth itself is changing. The landforms and oceans that may appear static now have been in constant flux for the entire history of life - mountains rise and fall, islands and lakes form and disappear, and whole continents crash together and break apart. Associates fluctuations in climate causes glaciers and ice caps to form and melt and sea levels to rise and fall. The events have an important on dispersal

Population Ecology

The biologists study population ecology, they focus on how the number and distribution of individuals i a population change over time. Example: Researches use mathematical models to predict the future of salmon populations. Many of these populations have declined due to over harvesting and the loss of habitat quality caused by pollution and dam construction. If the factors that affect population size can be described accurately enough, mathematical models can asses the impact of proposed dams, changes in weather patterns, altered harvest levels, or specific types of protection efforts. (population - a group of individuals of the same species that lives in the same area at the same time)

rain shadow

The dry region on the side of a mountain range away from the prevailing wind

Conservation biology

The five levels of ecological study are synthesized and applied in conservation biology. Conservation biology is the effort to study, preserve, and restore threatened genetic diversity in populations, species diversity in communities, and ecosystem function.

Photic zone for oceans

The intertidal and sunlit regions of the neurotic, oceanic, and benthic zones

Coriolis Force

The key to the Coriolis effect lies in the Earth's rotation. The Earth rotates faster at the Equator than it does at the poles. This is because the Earth is wider at the Equator. A point on the Equator has farther to travel in a day. In the Northern Hemisphere, wind from high-pressure systems pass low-pressure systems on the right. This causes the system to swirl counter-clockwise. Low-pressure systems usually bring storms. This means that hurricanes and other storms swirl counter-clockwise in the Northern Hemisphere. In the Southern Hemisphere, storms swirl clockwise. Fast-moving objects such as airplanes and rockets are influenced by the Coriolis effect. Pilots must take the Earth's rotation into account when charting flights over long distances. This means most planes are not flown in straight lines, even if the airports are directly across the continent from each other. The line between Portland, Maine, and Portland, Oregon, for instance, is very long, and fairly straight. However, a plane flying from Portland, Oregon, could not fly in a straight line and land in Portland, Maine. Flying east, the Coriolis effect seems to bend to the right, in a southerly direction. If the Oregon pilot flew in a straight line, the plane would end up near New York or Pennsylvania. [The invisible force that appears to deflect the wind is the Coriolis force. The Coriolis force applies to movement on rotating objects. It is determined by the mass of the object and the object's rate of rotation. The Coriolis force is perpendicular to the object's axis. The Earth spins on its axis from west to east. The Coriolis force, therefore, acts in a north-south direction. The Coriolis force is zero at the Equator.] The earth is a non-inertial frame of reference. - Any object moving over the surface of the earth will be affected by the rotation of the earth. - The rotation of the earth imparts an apparent force acting on any moving object. - The Coriolis force is zero at the equator and maximal at the poles. - The Coriolis force acts perpendicular to the direction of motion: to the right in the N hemisphere and to the left in the S hemisphere.

Salinity

The portion of solutes dissolved in water determines its salinity, generally the number of grams of solute per kilogram of water. As rain water percolates through soils and flows across rocks, it picks up solutes. The freshwater of ponds, lakes, and rivers has very low solute concentrations. However, as this freshwater steadily flows into the ocean, it continually adds soul. Over millions of years, this process has resulted in a relatively high concentration of solutes in seawater. The salinity of freshwater varies from about 0.06 to 0.03 parts per thousand, where as the salient of the open ocean is fairly constant at 35 parts per thousand. Sodium chloride has such high solubility n water tat it makes up about 86 percent of sea salt. Salinity has dramatic effects on osmosis and water balance in organisms; species have physiological adaptions that allow them to cope with a specific range in salinity. Thus salinity is a major determinant of the distribution of organisms in aquatic biomes.

Biotic and Abiotic Species interact

The range of every species on Earth is limited by a combination of abiotic and biotic factors that occurred in the past, and that occur in the present Example: Consider the case of the Argentine ant, Linepithema humile, native to South America and rapidly expanding around the world. These small ants form unusually large super colonies because they mix freely with other Argentine ants while fighting aggressively against native ants. This invasion creates a huge pest control problem in home, and farms, and it also has grave ecological implications. For example, horned lizards are in decline in southern California due to the disappearance of the native ants that they are specialized to eat. Argentine ants are dispersed by humans to different continents in food shipments like coffee. But these ants don't thrive everywhere they land - they are most successful in Mediterranean-like ecosystems that have adequate moisture, winters hat are not too cold, and summers that are not to hot. Soil moisture is also very important to the species range. After a study, researchers found that the interaction of biotic and abiotic factors slowed the spread of invasive ants more than abiotic factors alone. [LOOK AT GRAPH ON PAGE 1064] Argentine ants are at a competitive advantage in moist soils, but at a disadvantage compared to native ants in dry soils.

Nutrient Availability

The scarcity of nutrients limits growth rates in the photosynthetic organisms that provide food for other species. Ocean upwelling and Lake turnover affect nutrient availability in lakes and oceans.

lake turnover

The spring and fall turnovers occur in response to changes in air temperature. Without the spring and fall turnovers, most freshwater nutrients would remain on the bottom of lakes. The aquatic ecosystems would be much less productive as a result.

Biogeography

The study of how organisms are distributed geographically

biomass

The total mass of all organisms in a given population or geographical area; usually expressed as total dry weight

Why are the spring and fall lake turnovers important for aquatic ecosystems?

The turnovers bring nutrient-rich water from the bottom of the lake up to the top of the lake.

If the Earth's axis were at 90° to the Sun, what would be different?

There would be no seasons

Water Depth

Water absorbs and scatters light, so that the amount and types of wavelengths available to organisms change dramatically as water depth increases. Light availability has a major influence on productivity. At the surface of water, all wavelengths of light are equally available. But ocean water dramatically removes light in the red region of the visible spectrum (thats why ocean water has the blue hue in underwater scenes). Wavelengths in the red region are unavailable for photosynthesis underwater, despite the huge absorption peaks for red wavelength in key photosynthetic pigments like chlorophyll. The quality of light available to organisms also decreases rapidly with increasing depth. Further, seawater is rarely pure and may contain high concentrations of algae, sediments, and other light-reducing components. The turbidity of water is an important determinant of light penetration. The turbidity is sometimes caused by natural process such as erosion of river sediments by floodwaters and the erosion of costal sediments by ave action. Turbidity is also caused by many human activities, such as runoff from agricultural fields and algae blooms caused by nutrient pollution.

Water Flow

Water movement is a critical factor in aquatic ecosystems because it presents a physical challenge. It can literally sweep organisms away. Organisms that live in fast-cowing streams have to cope with the physical force of the water, which constantly threatens to move them down stream. Stream-dwelling organisms like mayfly larvae have streamlined shapes and behavioral adaptions that help them to maintain their position in the stream. Water flow can also influence non-mechanical aspects of the abiotic environment, including the availability of oxygen, light, and nutrients. For example, the fast moving water near the source of streams tends to be high in O2, clear, and low in nutrients. The slower-flowing water downstream tends to be lower in O2, more turbid, and more nutrient rich.

Aquatic Biomes: Freshwater - Wetlands

Wetlands are shallow-water habitats where the soil is saturated with water for at least part of the year. They are usually distinguished from terrestrial habitats by the presence of "indicator plants" that grow only in saturated soils. Water depth - They have only shallow water, and they have emergent vegetation (plants that grow above the surface of the water). All or most of the water in wetlands receives sunlight; emergent pants capture sunlight before it strikes the water Water flow and nutrient availability - Freshwater marshes and swamps are wetland types characterized by slow but steady flow of water. Bogs develop in depressions where water flow is low or nonexistent. Due to their stagnant water, bogs are oxygen poor or even anoxic, resulting in decomposition rates. Bogs are also nutrient poor. Marshes and swamps, in contrast, are relatively nutrient rich. Organisms - The combination of acidity, lack of available nitrogen, and anoxic conditions makes bogs extremely unproductive habitats. Marshes and swamps offer ample supplies of oxygenated water and sunlight, along with nutrients available from rapid decomposition - extremely productive. Marshes typically feature grasses, reeds, or other nonwoody vegetation. Swamps are dominated by trees and shrubs. There is little species overlap found between swamps, marshes, and bogs.

Hadley Cell

When average rainfall is mapped for regions around the glob, it is clear that areas length equator receive the most moisture. In contrast, locations about 30 degrees latitude north and south of the equator are among the driest on the planet. How Hadley Cells Work - Study Sheet

Wallace Line

While working in the Malay Archipelago, Wallace realized that the plants and animals native to the more northern and western islands were radically different from the species found on the more southern and eastern islands. Sumatra, to the northwest, has tigers, rhinos, and other species with close relatives in southern Asia. New Guinea, to the southeast, has tree kangaroos and other species with close relatives on Australia. but both islands are tropical wet forests. This biogeographical demarcation (a dividing line), now known as the Wallace line, separates species with Asian and Australian affinities (relationships). It exists because a deep trench in the ocean maintained a water barrier to dispersal, even when ocean levels dropped during the most recent glaciations. As a result, landforms on either side of the line remained isolated at a time when most of the other islands became connected. The species on Sumatra remained different from the ones on New Guinea because of the Wallace Line. The species could not disperse. (LOOK AT PICTURE ON PAGE 1063)

Which of the following statements regarding turnover is true? a. In fall turnover, dense water at 4°C sinks and disturbs sediments in the benthic zone. b. In fall turnover, dense water at 4°C rises and disturbs sediments in the benthic zone. c. The surface water gets to 4°C only by cooling. d. Fall turnovers and spring turnovers are exactly the same.

a. In fall turnover, dense water at 4°C sinks and disturbs sediments in the benthic zone.

Which aquatic zone produces the most grams of organic material/square meter/year? a.Littoral zone b. Benthic zone c. Limnetic zone d. Aphotic zone

a. Littoral zone Sunlight is abundant here along with nutrients from the substrate.

Which of the following statements about freshwater environments is true? a. Organisms that consume detritus are common in the benthic zones of lakes and ponds. d. Marshes and bogs are the most productive wetland habitats. c. Bogs are characterized by high water flow. d. Lakes and ponds are divided into zones according to the depth of the water and the amount of oxygen available.

a. Organisms that consume detritus are common in the benthic zones of lakes and ponds.

Aquatic biomes can be distinguished by chemical characteristics such as dissolved oxygen content and salinity and by physical characteristics such as water flow. Which five of the following statements about aquatic biomes are true? a. Temperature drives water movement in some lakes. b. All wetlands have soils that dry out periodically. c. Estuaries are very productive and are used as breeding grounds by many species of fish. d. Tropical coral reefs generally exist in relatively shallow areas of the ocean. e. Wetlands have slow water movement or no water movement and no turnover. f. The lowest levels of dissolved oxygen in a stream are generally found in its turbulent headwaters. g. A freshwater organism permanently attached to the substrate would be unlikely to survive and reproduce in an estuary.

a. Temperature drives water movement in some lakes. c. Estuaries are very productive and are used as breeding grounds by many species of fish. d. Tropical coral reefs generally exist in relatively shallow areas of the ocean. e. Wetlands have slow water movement or no water movement and no turnover. g. A freshwater organism permanently attached to the substrate would be unlikely to survive and reproduce in an estuary.

Where would a Hadley cell be found? a. between equator and 30°N b. between 30°N and 60°N c. above 60°N d. between eqator and 60°N

a. between equator and 30°N there are two other circulation cells in the Northern hemisphere and two others in the Southern hemisphere, but they are not called Hadley Cells

Which is a likely biotic factor limiting songbird distribution in Hawaii to alpine habitats? a. insects causing fatal diseases in songbirds at lower altitudes b. moisture c. oxygen content d. temperature

a. insects causing fatal diseases in songbirds at lower altitudes

Which would you expect to see most reduced in a desert plant? a. leaves b. seed coats c. roots d. flowers

a. leaves

Typically, where are oxygen levels highest and nutrient levels lowest in a stream? a. near its source b. where it forms an estuary c. near its mouth, or end d. where it flows through a swamp or marsh

a. near its source

Which of these is characteristic of the photic zone of a freshwater biome? a. the presence of algae b. relatively cool water c. relatively stable water temperature d. dead organic matter e. low oxygen level

a. the presence of algae "Photic" means light, and light encourages the growth of photosynthetic organisms.

Terrestrial Biomes: Tropical Wet Forest

also called tropical rain forests. found in equatorial regions around the world. plants in this bio have broad leaves and are evergreen. favorable yearend growing conditions produce riotous growth, leading to extremely high productivity, aboveground biomass, and species diversity. it is not unusual to find over 200 tree species in a single study plot. temperature - compared to other biomes, tropical wet forests show almost no seasonal variation in temperature. temperatures are high enough to support growth throughout the year precipitation - even the driest month of the year (November) receives over 5 cm of rain fall - considering more than the annual rainfall of many deserts.

Terrestrial Biomes: Boreal Forests

also known as taiga. stretches across most of Canada, Alaska, Russia, and norther Europe and are dominated by highly cold-tolerant conifers, including pines, spruce, fir, and larch trees. Productivity is low, but aboveground biomass is high because slow-growing tree species may be long lived and gradually accumulate large standing biomass. Boreal forests also have exceptionally low species diversity - there are just seven or fewer tree species in Alaska. They also lack most elements of structure seen in tropical or even temperate forests - they often have just a tree ayer and a ground layer. temperature - very cold winters and cool, short summers precipitation - annual precipitation is low, but temperatures are so cold that evaporation is minimal; as a result, moisture is usually abundant enough to support tree growth.

Invasive Species

an exotic species that is introduced to a new area, spreads rapidly, and competes successfully with native species.

Terrestrial Biomes: Temperate Grasslands

are commonly called prairies in North America and steppes in central Eurasia. Grasses re the dominant life-form in temperate grasslands for one of two reasons: (1) Conditions are to dry to enable tree growth or (2) encroaching trees are burned out by prairie fires. In contrast to deserts, plant life is extremely dense - virtually every square centimeter is filled, not only on the surface, but also underground where root stems are extensive. Although the productivity of temperate grasslands is generally lower than forest communities, grassland soils are often highly fertile. temperature - plant growth is possible only in spring, summer, and fall months when moisture and warmth are adequate. precipitation - conditions are still slightly too hot and dry to support forests; average annual precipitation in Konza Prairie (Kansas) is 83.4 cm.

Aphotic zone for oceans

areas that do not receive sunlight (same for lakes and ponds)

Intertidal "between tides" zone

consist of a rocky, sandy, or muddy beach that is exposed to the air at low tide but submerged at high tide

photic zone

consists of the littoral, limnetic, and benthic zones that receive sunlight

littoral "seashore" zone

consists of the shallow waters along the shore, where flowering plants are rooted

Weather

consists of the specific sort-term atmospheric conditions of temperature, precipitation, sunlights, and wind

carbon fixation

conversion process of inorganic carbon (carbon dioxide) to organic compounds by living organisms.

detritus

dead organic matter

Different aquatic environments are distinguished by ____

depth of water and rate of water movement

Which of the following organisms is likely to have the widest geographic distribution? a. Thermus aquaticus bacteria b. cheetahs c. songbirds d. polar bears e. bacteria

e. bacteria

Contrast the productivities of the intertidal, neritic, and oceanic zones of marine environments. Explain why large differences in productivity exist: Productivity in the oceanic zone is ____ even though lights ______ - because nutrients are ____

extremely low; available at the surface; scarce

Terrestrial Biomes: Subtropical Deserts

found throughout the world at 30 degrees latitude north and south. desert species adapt tot eh extreme temperatures and aridity by growing at a low rate year-rounds, or breaking dormancy and growing rapidly in response to any rainfall. Cacti can grow year-round because they have no leaves, or small leaves modified as spines; a thick, waxy coating; and the CAM pathway for photosynthesis. The average productivity of desert communities is extremely low. temperature - mean monthly temperatures in subtropical deserts cary more than tropical wet climates. Temperatures fall below freezing in some subtropical deserts precipitation - the most striking feature of the subtropical desert climate is low precipitation; average annual precipitation in Yuma, Arizona is just 7.5 cm.

Contrast the productivities of the intertidal, neritic, and oceanic zones of marine environments. Explain why large differences in productivity exist: Productivity in the intertidal zone is ___ because sunlight is ____ and because nutrients are ______

high; readily available; available from estuaries and deep-ocean currents

Contrast the productivities of the intertidal, neritic, and oceanic zones of marine environments. Explain why large differences in productivity exist: Productivity in the neritic zone is ____ because sunlight is ______ and because nutrients are

high; readily available; available from estuaries and deep-ocean currents

limnetic zone

is offshore and consists of water that receives enough light to support photosynthesis

The _____ biome is the largest of Earth's biomes.

marine

Over the course of the year, regions at or near the equator receive _____ sunlight per unit area - and thus _____ energy in the form of heat - than regions that are closer to the poles

much more; much more - At the equator, the Sun is often directly overhead. As a result, sunlight strikes the surface at or close to an angle of 90 degrees. At these angles, Earth receives maximum amount of solar radiation per unit area - Because Earth's surface slopes away from the equator, the Sun strikes the surface at lower and lower angles moving toward the poles. When sunlight arrives at a low angle, much less energy is received per unit area. The pattern of decreasing average temperature with increasing latitude is caused by the Earth's spherical shape.

Terrestrial Biomes: Arctic Tundra

occurs throughout the arctic regions of the Northern Hemisphere. tundra has low species diversity, low productivity, and low aboveground biomass - and it is treeless. Most tundra soils are in the perennially frozen state known as permafrost, which limits both the release and uptake of nutrients. Unlike desert biomes, however, the ground surface in tundra communities is completely covered with plants or lichens. Animal diversity also tens to be low, although insect abundance - particularly of biting flies - can be staggeringly high. temperature - the growing season is very short, 10-12 weeks at most in Barrow, Alaska; for the remainder of the year, temperatures are below freezing precipitation - extremely low, but many artifice soils are saturated year-round due to extremely low evaporation rates.

emergent plants

plants that grow above the surface of the water

Anthropogenic Biomes

represent the global ecological patterns created by sustained direct human interactions with ecosystems. The exponential increase in the human population is driving land-use changes and other impacts that are so significant that some researchers have called for a new epoch of history, the Anthropocene. - More than 75 percent of Earth's ice-free land shows evidence of direct alteration by humans - for example, farming, logging, and urban development (not including the effects of population, invasive species, or climate change) - The remaining regions, or wild lands, account for just 11 percent of terrestrial net primary productivity. Humans are also changing the global distribution of ecosystems in amore indirect way - by changing the global climate.

The benthic zone of aquatic environments is defined as the _____.

substrate at the bottom of the body of water

Photosynthesis, plant growth, and NPP are maximized on land when ____

temperatures are warm and conditions are wet. Conversely, photosynthesis cannot occur efficiently at low temperatures or under drought stress. Photosynthetic rates are maximized in warm temperatures, when enzymes work efficiently, and in humid weather, when storm can remain open and CO2 is readily available.

Oceanic zone

the "open ocean" - the deepwater region beyond the continental shelf

Continental shelf

the gently, slopping, submerged portion of a continental plate

Dispersal

the movement of individuals from their place of origin to the location where they live and breed as adults. Example: The formation 3 million years ago of the land bridge from North America to South America, Isthmus of Panama, created opportunities for dispersal from each continent to the other, introducing new biotic interactions on both continents. Meanwhile, the same geological event separated the Pacific Ocean from the Caribbean Sea, creating barriers to dispersal for marine species. ( Alfred Wallace was among the first to document this phenomenon)

Climate

the prevailing , long-term weather conditions found in a area

Ecology

the study of how organisms interact with each other and their environment.