AP BIO

ecology

includes the subdisciplines of physiological evolutionary, and behavorial ecology, is concerned with how an organisms structure, physiology, and behavior meet the challenges posed by its environment.

organismal ecology

includes the subdisciplines of physiological evolutionary, and behavorial ecology, is concerned with how an organisms structure, physiology, and behavior meet the challenges posed by its environment.

population ecology

Population: a group of individuals of the same species living in an area. Population ecology analyzes factors that affect population size and how and why it changes through time.

Community ecology

Community ecology- Community: a group of populations of different species in an area. Community ecology examines how interactions between species, such as predation and competition, affect community structure and organization.

Ecosystem ecology

 Ecosystem- the community of organisms in an area and the physical factors with which those organisms interact. Ecosystem ecology emphasizes energy flow and chemical cycling between organisms and the environment.

landscape ecology

 Landscape (or seascape)- a mosaic of connected ecosystems. Research in landscape ecology focuses on the factors of controlling exchanges of energy, materials, and organisms across multiple ecosystems.



 

Global ecology & definition of biosphere

Biosphere: the global ecosystem-the sum of all the planets ecosystems and landscapes. Global ecology examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere.

Why is it important for a biologist to know about the Earth’s climate?

 it is the most significant influence on the distribution of organisms on land. Biologists must know about the climate of an area so that if it changes in a way that is not supposed to in a dramatic way, they can see how it affects the organisms.

What are two main factor’s that create the variations in the Earth’s climates?

The two main factors that create variations in the Earth's climate is the temperature onto Earth and the Earths movement in space. As the sun warms the surface of the Earth, the warming establishes temperature variations, different temperatures in the distribution of water, and evaporation of water which cause dramatic latitudnial variations in climate.

How does latitude affect sunlight intensity?

 Latitude affects sunlight intensity as the Earths curved shape causes latitundial variation of sunlight. More sunlight strikes the equator more directly leading to mote heat and light compared to higher latitutdes which sunlight strikes at a oblique angle.

seasonality effects on local and regional effect on climate

Seasonality happens in middle to high latititudes due to the Earth being on a tilt and its annual passage around the sun cause strong seasonal cycles in day length, solar radiation, and temperature. Seasonal changes in wind patterns also affect ocean currents which sometimes causes the upwelling of cold water from deep ocean layers- this causes the fish market to be more succesful that yea

bodies of water effects on regional and local climate

Ocean currents influence climate along the coasts of continents by heating or cooling overlying air masses that pass across land. Coastal regions are also generally wetter than inland areas at the same latitude. Because of the high specific heat of water, oceans and large lakes ten to moderate the climate of nearby land. During a hot day, when land is warmer than the water, air over the land heats up and rises, drawing a cool breeze from the water across the land. In contrast, because temperatures drop more quickly over ladn than over water at night, air over the now warmer water rises, drawing cooler air from the land back out over the water and replacing it with warmer air from offshore.

What is the effect of global oceanic circulation? What drives this? Why is important?

The effect of global oceanic circulation is it moderates the tempereratures throughout the world. Water is warmed at the equator and flows north and south towards the poles, where it cools. Trade winds drive the oceanic circulation. Global Oceanic Circulation is important because it decreases in certain climates.

Mounatins

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 Mountains influence air flow over land. When warm, moist air approaches a mountain, the air rises and cools as it becomes less condensed, releasing moisture on the windward side of the peak. On the leeward side, cooler, dry air descends, absorbing moisture and producing a "rain shadow." Such leeward rain shadows determine where many deserts are found, including the Mojave Desert of western North America. Mountain also affect the amount of sunlight reaching an area and thus the local temperature and rainfall. South-facing slopes in the northern hemisphere receive more sunlight than north-facing slopes and are therefore warmer and dries. These physical differences influence spieces distribution locally. Also, as elevation increases, temperature drops which can be a reason that high elevation communities near the equator can be similair to lower elevation communities far from the equator.

What is a microclimate? Make sure to explain the difference between macroclimate and microclimate in your answer. Give an example of a microclimate.

Microclimate: Climate patterns on a very fine scale, dissimilair to that of a macroclimate (the overall climate of region usually a large geographic area, An example of a microclimate is  the specific climate conditions underneath a log. Another example is two sides of a mountain which is experiencing the rainshadow effect.

abiotic

nonliving

biotic

living

What is Global climate change?  What are some of the ways the climate is changing?

Global climate change is a directional change to the global climate that last three decades or more (as opposed to short-term changes in the weather). Some ways the climate is changing is earth has warmed an average of 0.9degrees C since 19000 and is projected to warm 1-6 c more by the year 2100. Wind and preciptation patterns are also shifting, and extreme weather events (such as droughts and storms) are occuring more frequently.

What changes occurred since the last ice age and how did that affect organisms?

 During the last ice age, continental glaciers covered much of North America and Eurasia and as the climate warmed,, the glaciers retreated. As the glaciers retreated, tree species distributions expanded northward. A detailed record of these changes is captured in fossilized pollen deposits that haven been discovered in lakes and ponds, These fossilized pollen data show that while some species moved northward rapidly others moved more slowly. For species that moved more slowly, the expanison of their ranges lagged several thousand years behind the shift in suitable habitat.

Give a specific example of a recent climate change and it’s effects.

A specific example of a recent climate change is as the climate has warmed, 22 of 35 european butterfly species studied have shifted their ranges farther north by 35-240 km in recent decades. Some effect of the butterfly range changing is it impacts other ecosystems and can change the food chain or pyramid and can out compete other organisms for land and food.. When climate change enables or causes a species to expand its range into a new geographic area, other organic living there may be harmed.

What two factors control the distribution of terrestrial biomes? (Define Biome and disturbance)

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Two factors that control the distribution of terrestrial biomes (biomes- a large naturally occurring community of flora and fauna occupying a major habitat) are climate and vegetation type.

Disturbance-a temporary change in environmental conditions that causes a pronounced change in an ecosystem like a storm, fire, or human activity

How does temperature and precipitation impact the distribution of terrestrial biomes?

 Temperature and precipitation impact the distribution of terrestrial biomes as biomes can have similar amount of rain, but since they have different temperatures, the distribution of plant and animal species will be different. A biome can have a similar temperature to another, but if they have different amount of rain the distribution will be different. (Based on 52.10 climograph) "the range of precipitation in northern coniferous and temperate forests is similar but that temperate forests are generally warmer. Grasslands are typically drier than either kind of forest, and deserts are drier still"

evergreen tropical forest

Largely found in the temperate mid-latitudes of Siberia, Canada, Australia, Africa, Scandinavia, Indonesia, and more. Found in areas receiving more than 234 cm of rainfall and having a monthly mean temp of 20 C or higher in the coldest months. Tropical evergreen forests are dense, multilayered, and harbors many types of plants and animals. These forests are found in areas receiving heavy rainfall. Include trees such as conifers and holly in cold climates, eucalyptus, Live oak, acacias, magnolia, and banksia, in more temperate zones, and rainforest trees in tropical zones. Few of the common animal species found in tropical forests are chinchona, monkeys, elephants, deer, lemur, one-horned rhino, birds, sloths, bats, scorpions, snails, etc.

deciduous tropical forest

Occur in drier areas of north and south of the tropical rainforest belt, south or north of the subtropical deserts- one between 10 and 20 degrees north latitude and the other between 10 and 20 south latitude. Tropical deciduous forests occur in climates that are warm year-round and may receive several hundred cm of rain per year. Though these forests occur in climates that are warm year-round and may receive several hundred cms of rain per year, they have long dry seasons which last several months and vary with geographic location. These forest formations are dense and lush during the wet summers, but become a dry landscape during the dry winters when trees shed their leaves. Shedding their leaves allow trees to conserve water during dry periods.  Deciduous tropical forests are sensitive to excessive burning, deforestation, overgrazing, and exotic species. Comprised of species such as the shala tree, kino tree, and jambul, the forest provides rich habitat for many animal species, among them the sloth bear, chousingha, and dhole.

tropical savanna

The tropical savanna is a biome characterized by tall grasses and occasional trees. Sandwiched between tropical rainforests and desert biomes. Occur in warm regions where there's a very rainy and humid wet season, and a drought-like and fire-prone dry season. Found at around 10-20 degrees latitude both north and south. Mainly found in Africa, Australia, South America, and India. Largley a flat expanse, with very few trees and a lot of grasses. Although yearly rainfall is high plant and animal life is limited mainly by water due to the drought seasons. The overall mean temp is a high of 30 C and lows down to 20 C. Average yearly rainfall is around 800-1200 mm. Grasses, sedges, legumes, some shrubs, and sporadic trees are common. Animals like Marsh deer, savanna rabbit, ocelots, zebra, hippos, crocidiles, and many insects are common.

hot desert

Found near the tropic of cancer and the tropic of capricorn. Rainfall is an average of 15 cm / year or under. Occur in low latitudes. Don’t have very many plants, but do have some low down plants like ground hugging shrubs like Prickley Pears. The only animals they have that can survive have the ability to burrow under ground like small nocturnal carnivores and insects, anarchids, reptiles, and birds.  Range from 20 to 25 degrees celsius. The extreme maximum temp for Hot desert ranges from 43.5-49 C. Warm throughout the fall and spring and very hot during the summer. Winters usually have little to no rainfall.

cold dessert

Cold deserts are near the Artic part of the world. A cold desert is a desert that has snow in the winter instead of just dropping a few degrees in temp like they would in a Hot Desert. It never gets warm enough for plants to grow. Just maybe a few grasses and mosses. The animals in Cold desert also have to burrow but in this case to keep warm, not cool. Cold Deserts temp in winter range from -2 to 4 degrees c and in the summer 21-26 C. Average rainfall averages to be 15-25 cm per year. The summer and the beginning of the spring are barely warm enough for a few lichen, grasses, and mosses to grow. Animals like Antelope, ground squirrels, jack rabbits, and kangaroo rats live here.

thorn desert

Seasonal rainfall averaging 250 to 500 mm. Covers a large part of Southwestern North America and Southwestern Africa. Consists primarily of thorny small trees that shed their leaves seasonally in the dry season (Mimosa and Acacia). Cacti and other armed succulents are common. Found in regions with low to moderate elevations. Animals that inhabit thorn desert include a variety of birds, reptiles, and mammals. Temperature ranges from 23 to 50 C.

savanna

Savana occurs in equatorial and subequatorial regions



Seasonal rainfall averages 30-50 cm per year. The dry season can last up to eight or nine months



The savanna is warm year-round, averaging  24-29 degrees celsius, but with somewhat more seasonal variations than in tropical forests.



The scattered trees found at different densities in the savanna often are thorny and have small leaves, an apparent adaption to the relatively dry conditions. Fires are common in the dry season, and the dominant plant species are fire-adapted and tolerant of seasonal drought. Grasses and small nonwoody plants called forbs, which make up most of the ground cover, grow rapidly in response to seasonal rains and are tolerant of grazing by large mammals and other herbivores



Large plant-eating mammals, such as wildebeests and zebras, and predators, including lions and hyenas, are common inhabitants. However, the dominant herbivores are actually insects especially termites. During seasonal droughts, grazing mammals often migrate to parts of the savanna with more forage and scattered watering holes.



The earliest humans may have lived in savannas. Fires set by humans may help maintain this biome, though overly frequent fires reduce tree regeneration by killing the seedlings and saplings. Cattle ranching and overhunting have led to declines in large-mammal populations

chaparral

This biome occurs in midlatitude coastal regions on several continents, and its many names reflect its far-flung distribution: chapparal in North America, matorral in Span and Chile, garigue and maquis in Southern France and fynbos in South Africa.



Precipitation is highly seasonal, with rainy winters and dry summers. Annual precipitation generally falls within the rang of 30-50cm



Fall, winter, and spring are cool, with average temps in the rang of 10-12 C. Average summer temps can reach 30 C and daytime maximum temp can exceed 40 C



 Chaparral is dominated by shrubs and small trees, along with many kind of grasses and herbs, Plant diversity is high, with many species confined to a specific, relativeley small geographic area. Adaptions of the woody plants to drought include their tough evergreen leaves, which reduce water loss. Adaptions to fire are also prominent. Some of the shrubs produce seeds that will germinate only after a hot fire; food reserves stored in their fire resistant roots enable them to resprout quickly and use nutrients released by the fire.



Native mammals include browsers, such as deer and goats, that feed on twigs and buds of woody vegetation, and a high diversity of small mammals. Chaparral areas also support many species of amphibians, birds and other reptiles, and insects.



Chaparral areas have been heavily settled and reduced through conversion to agriculture and urbanization. Humans contribute to the fires that sweep across the chapparal.

temperate grassland

The veldts of South Africa, the puszta of Hungary, the pampas of Argentina and Uruguay, the steppes of Russia, and the plains and prairies of  central North America are examples of temperate grasslands.



Precipitation is often highly seasonal, with relatively dry winters and wet summers. Annual precipitation generally averages between 30 and 100cm. Periodic drought is common.



Winters are generally cold, with average temps falling below -10 C. Summers, with average temps often approaching 30 C are hot.



The dominant plants are grasses and forbs, which vary in height from a few cms to 2 m in tallgrass prairie. Many grasslands plants have adaptations that help them survive periodic, protracted droughts and fire. Grazing by large mammals helps prevent establishment of woody shrubs and trees.



Native mammals include large grazers such as bison and wild horses, Temperate grasslands are also inhabited by a wide variety of burrowing mammals, such as prairie dogs in North America.



Deep, fertile soils make temperate grasslands ideal places for agriculture, especially for growing grains. As a consequence, most grassland in North America and much of Eurasia has been converted to farmland. In some drier grasslands, cattle and other grazers have turned pats of the biome into desert. 

coniferous forest (boreal forest/taiga)

Extending in a broad band across northern North America and Eurasia to the edge of the artic tundra, the northern coniferous forest, or taiga, is the largest terrestrial biome on Earth. Annual precipitation generally ranges from 30 to 70 cm, and periodic droughts are common. However, some coastal coniferous forests of the US Pacific Northwest are temperate rain forests that may receive over 300 cm of annual precipitation. Winters are usually cold; summers may be hot. Some areas of coniferous forest in Siberia typically range in temperature from -50 C in winter to over 20 C in summer.



Northern coniferous forests are dominated by cone-bearing trees, such as pin, spruce, fir, and hemlock, some of which depend on fire to regenerate. The conical shape of many conifers prevents too much snow from accumilating and breaking their branches and their needle- or scale-like leaves reduce water loss. The diversity of plants in the shrub and herb layers of these forests is lower than in temperate broadleaf forests.



While many migratory birds nest in northern coniferous forests, other species reside there year-round. The mammals of this biome, which include moose, brown bears, and Siberian tigers, are diverse. Periodic outbreaks of insects that feed on the dominant trees can kill vast tracts of trees.



Although they have not been heavily settled by human populations, northern coniferous forests are being logged at an alarming rate, and the old-growth stans of these trees may soon disappear.

temperate broadleaf forest

Temperate broadleaf forest Is found mainly at midlatitudes in the Northern Hemisphere, with smaller areas in Chile, South Africa, Australia, and New Zealand.



           Precipitation can average from about 70 to over 200 cm annually. Significant amounts fall during all seasons, including summer rain and, in some forests, winter snow.



Winter temps average 0 C. Summers, with temps up to 35 C are hot and humid.



A mature temperate broadleaf forest has distinct vertical layers, including a closed canopy, one or two strata of understory trees, a shrub layer, and an herb layer. There are few epiphytes. The dominant plants in the Northern Hemisphere are deciduous  trees, which drop leaves before winter, when low temps would reduce photosynthesis and make water uptake from frozen soil difficult. In Australia, evergreen eucalyptus trees dominate these forests.



In the Northern Hemisphere, many mammals hibernate in winter, while many bird species migrate to warmer climates. Mammals, birds, and insects make use of all the vertical layers of the forest.



Temperate broadleaf forest has been heavily settled on all continents.  Logging and land clearing for agriculture and urban development cleared virtually all the original deciduous forests in Northern America. However, owing to their capacity for recovery, these forests are returning over much of their former range.

tundra

Tundra covers expansive areas of the Artic, amounting to 20% of Earth's land surface. High winds and low temperatures produce similar plant communities, called alpine tundra, on very high mountaintops at all latitudes, including the tropics.



Precipitation averages from 20 to 60 cm annually in artic tundra but may exceed 100 cm in alpine tundra.



Winters are cold, with averages in some areas below -30 C. Simmer temps generally average less than 10 C.



The vegetation of tundra is mostly herbaceous, consisting of a mixture of mosses, grasses, and forbs, along with some dwarf shrubs and trees and lichens. A permanently frozen layer of soil called permafrost restricts the growth of plant roots.



Large grazing musk oxen are resident, while caribou and reindeer are migratory, Predators include bears, wolves, and foxes. Many bird species migrate to the tundra for summer nesting.



Tundra is sparsely settled but has become the focus of significant mineral and oil extraction in recent years.

why are aquatic biomes important to consider

Aquatic biomes are important to consider because since they cover 75% of Earth's surface is water, it greatly impacts the biosphere. Water evaporated from the oceans provides most of the planet's rainfall. Marine algae and photosynthetic bacteria supply much of the world's oxygen and consume large amounts of atmospheric carbon dioxide. Ocean temperatures have a major effect on global climate and wind patterns, and along with large lakes, oceans tend to moderate the climate of nearby land.

what characterizes aquatic biomes and how is this different from terrestrial biomes

Unlike terrestrial biomes, aquatic biomes are characterized primarily by their physical an chemical environment. They also show far less latitudinal variation, with all types found across the globe. Terrestrial biomes are based on land, while aquatic biomes include both ocean and freshwater biomes.

photic zone

The upper region where there is sufficient light for photosynthesis

aphotic zone

the lower region where little light penetrates

pelagic zone

both the photic zone and aphotic zone

abyssal zone

deep in the aphtoic zone- the part of the ocean 2,000-6,000m below the surface

benthic zone (define benthos and detritus)

At the bottom of all of these aquatic zones, deep or shallow, is the benthic zone. Made up of sand and organic and inorganic sediments, the benthic zones is occupied by communities of organisms called benthos (animals that live on the sea floor). A major source of food for many benthic species is dead organic matter called detritus (organic matter produced by the decomposition of organisms) which rains down from the productive surface waters of the photic zone.

thermocline

a transition between the warmer mixed water at the surface where sunlight penetrates to the cooler deeper water where sunlight does not penetrate. Its created when thermal energy from sunlight warms surface waters to whatever depth the sunlight penetrates, but the deeper waters remain quit cold.

turnover- why does it occur- why is it important

 the mixing of waters as a result of changing water-temperature profiles in a lake. This turnover sends oxygenated water from a lake's surface to the bottom and brings nutrient-rich water from the bottom to the surface. This occurs in both spring and autumn. It occurs because lakes tend to be particularly layered with respect to temperature, especially during summer and winter, but many temperate lake undergo a semiannual mixing of their waters as a result of changing temperature profiles. It is important because it allows aquatic life to inhabit the entirety of the lake as oxygen becomes more available.

What factors affect the distribution of species? Give a specific example. 

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 The factors that affect the distribution of species is are both ecological factors and evolutionary history. For example kangaroos are only found in Australia and fossil evidence indicates that kangaroos and their close relatives originated in Australia, roughly 5 million years ago. At that time Australia was not connected to any other landmasses making kangaroos only occur in Australia. Ecological factors are also important. Within Australia there are many different species of Kangaroo depending on where it is. Red kangaroo occurs in the arid grassland of central Australia, but not in the tall, open forests of eastern Australia. Both biotic and abiotic factors affect the distribution of a species. For example the saguaro cactus is found almost exclusively in the Sonoran Desert of the southwestern US and northwestern Mexico. To the north their range is limited by an abiotic factor of temperature and water. Biotic factors like disease and predators effect the growth of the cactus as well.

Define adaptive radiation and it’s relationship to the distribution of species. Give a specific example

 Adaptive radiation- a rapid increase in the # of species with a common ancestor, characterized by great ecological  and morphological diversity. It relates to dispersal because long distance dispersal can cause adaptive radiation. The diversity of Hawaiian silver swords is one example of adaptive radiation that was possible only with the long-distance dispersal of an ancestral tarweed from North America.

What is dispersal? How does it affect distribution. Give an example.

 Dispersal- the movement of individuals or gametes away from their area of origin or from centers of high population density. This affects distribution as it increases their distribution around the world and does limit it to one place. An example is while land-bound kangaroos have not reached Africa under their own power, other organisms that disperse more readily, such as some birds have.  Another example is dandelions have seeds that have hairs so that they can disperse to new environments.

 How do biotic factors affect species distributions? Give two examples.

Biotic factors affect the distribution of species because the ability of a species to survive and reproduce is reduced by its interactions with other species, such as predators or herbivores. For example, there is an inverse relationship btwn the abundance of sea urchins and seaweeds. Where urchins that graze on seaweeds and other algae are common, large stands of seaweed do not become established.  The presence or absence of pollinators, food resources, parasites, pathogens, and competing organisms can act as a biotic limiting on species distribution

temperature impact on the abiotic factors on the distribution of organisms

The rising sea temperatures have affected the geographic range of the sea urchin C. rodgersii. Since 1950, water temps along the cost of Tasmania have increased from 11.5 c to 12.5 c. This enabled C. rodgersii-whose larvae fail to develop properly if temps drop below 12 c- to expand its range to the south. This has resulted in algae growth to decrease due to them being destroyed by the urchins.

water and oxygen impact on the abiotic factors on the distribution of organism

Water- many amphibians, such as the tiny frog, are particularly vulnerable to drying b/c they use their moist, delicate skin for gas exchange impacting where they are distributed.



Oxygen-Oxygen affects the distribution of fish in aquatic environments as not all fish can live in areas low in oxygen like in deep oceans and lakes.

salinity impact on abitoic factors on the distribtuion of organisms

The salt concentration of water in the environment affects the water balance of organisms through osmosis. Most aquatic organisms are restricted to either freshwater or saltwater habitats by their limited ability to osmoregulate. Although most terrestrial organisms can excrete excess salts from specialized glands or in feces or urine, high salinity habitats typically have few species of plants or animals.  Salmon that migrate between freshwater streams and the ocean use both behavioral and physiological mechanisms to osmoregulate. They balance their salt by adjusting the amount of water they drink and by switching their gills from taking up salt in fresh water to excreting salt in the ocean.

sunlight impact on abiotic facotrs on the distribution of organisms

Too little sunlight can limit the distribution of photosynthetic species. In forests, shading by leaves makes competition for light especially intense, particularly for seeding growing on the forest floor. In the ocean, most plants live towards the surface due to sunlight not penetrating deep. Too much sunlight can increase temperature stress if animals and plants are unable to avoid light or to cool themselves through eva

rocks and soil impact on abiotic facotrs on the distribution of organisms

In terrestrial biomes, the ph, mineral composition, and physical structure of rocks and soil limit the distribution of plants and thus of the animals that feed on them, contributing to the patchiness of terrestrial ecosystems. The pH of soil can limit the distribution or organisms directly, through extreme acidic or basic conditions, or indirectly, by affecting the solubility of toxins and nutrients. Soil phosphorus, for instance, is relatively insoluble in basic soils and precipitates into forms unavailable to plants. In a river, the composition of rocks and soil that make up the substrate (riverbed) can affect water chemistry, which in turn influences the resident organisms. In freshwater and marine environments, the structure of the substrate determines the organisms that can attach to it or burrow into it.

 How do ecological change and evolution affect one another? Give a specific example in your explanation.

Ecological change and evolution affect one another because ecological interactions can cause evolutionary change and vice versa. As the adaptive radiation of plants species continued over time, the appearance of new plant species provided new habitats and new sources of food for insects and other animals. In turn, the availibilty of new habitats and new food sources for insects and other animals., leading to further ecological changes. Ecological and evolutionary changes had ongoing and major effects upon one another. Rapid evolution can also cause ecological change. For example, Trinidadian guppy population evolve rapidly when predators are removed: guppy color patterns change and huppies produce fewer but large offspring. In turn, the evolution of larger body sizes altered the availability of nitrogen in these stream ecosystems. Larger fish excrete more nitrogen than smaller fish and nitrogenous waste contribute to the growth of primary producers such as algae.

Population

a group of individuals of a single species living in the same general area. Members of a population rely on the same resources, are influenced by similar environmental factors, and are likely to interact and breed with one another. Often are described by their boundaries and size (# of individuals living within those boundaries)

density

\-the # of individuals per unit area or volume: the # of oak trees per square kilometer in the Minnesota county or the # Escherichiacoli bacteria per milliliter in a test tube.

dispersion

the pattern of spacing among individuals within the boundaries of the population

Mark-recapture method

\-a sampling technique used to estimate the size of animal population: Scientists typically begin by capturing a random sample of individuals in a pop. They tag, or "mark", each individual and then release it. With some species, researchers can identify individuals without physically capturing them. After waiting for the marked or otherwise identified individuals to mix back into the pop., usually a few days or weeks, scientists capture or sample a second set of individuals

The method assumes that marked and unmarked individuals have the same probability of being captured or sampled, that the marked organisms have mixed completely back into the population, and that no individuals are born, die, immigrate, or emigrate during the resampling interval.

immigration

the influx of new indivudals from other areas

emigration

the movement of individuals out of a population and into other locations

 describe the mark and recapture method and the equations used.

 



With some species, researchers can identify individuals without physically capturing them. After waiting for the marked or otherwise identified individuals to mix back into the pop., usually a few days or weeks, scientists capture or sample a second set of individuals. The # of the marked animals in the second sampling (x) divided by the total number of animals captured in the second sampling (n) should equal the number of individuals marked and released in the first sampling (s) divided by the estimated population size (N). x/n = s/n or, solving for pop. Size N=sn/x



The method assumes that marked and unmarked individuals have the same probability of being captured or sampled, that the marked organisms have mixed completely back into the population, and that no individuals are born, die, immigrate, or emigrate during the resampling interval

What are the main patterns of dispersion with a population’s geographic range? What clues do these provide to population ecologists?

The main patterns of dispersion with a population's geographic range are clumped (individuals are aggregated in patches- plants and fungi are often clumped where soil conditions and other environmental factors favor germination and growth, clumping of animals may be associated with mating behavior), uniform (evenly spaced pattern of dispersion may result from direct interactions btwn individuals in the population- some plants secrete chemicals that inhabit the germination and growth of nearby individuals that could compete for resources- animals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality- the defense of a bounded physical space against encroachment by other individuals), and random dispersion (unpredictable spacing- the position of each individual in a population is independent of other individuals- this pattern occurs in the absence of strong attractions of repulsions among individuals of where key physical or chemical factors are relatavely constant across the study area. These clues provide population ecologists ways to properly survey the population of a species based on their pattern of dispersion

demography

the study of vital statistics (birth death and migration rates) of populations and how they change over time.

life tables

summarizes the survival and reproductive rates of individuals in specific age-groups within a population.

cohort

To construct a life table, researchers often follow the fate of a cohort- a groups of individuals of the same age, from birth until all of the individuals are dead. Building the life table requires determining the proportion of the cohort that survives from one age-group to the next.

survivorship curves

1.  a plot of the proportion or numbers in a cohort still alive at each age. (type I II and III) Type 1- many offspring- not many survive (r species)



Type 2- throughout the organisms lifespan- constant death rate over organisms lifespan



Type 3- (K species) produce not many offspring- but offspring that are born have high chance of survival till old age.

Reproductive rates (explain the effects on population size)

 Researchers often ignore males of a species and focus on females to get a reproductive rate because only females produce offspring. Ecologists must estimate the amount of females in a population (direct counts and mark and capture method) to gather a reproductive rate. Reproductive rates have impacts on population size due to it being the reason if populations can grow or not. Age specific reproductive rates vary considerably between species- squirels have litter of two to six young once a year for less than a decade- whereas oak trees drop thousands of acorns a year for tens of hundreds of years

explain the three different types of survivorship curves

Type 1- elephant- produces not many young- young that are produced are cared for and have high chance of survival because they are cared for

type 2- Lizards- the same change of death throughout entire lifespan

type 3-Oak tree- drop thousands of acorns each year but not likely for many acorns to actually develop into a tree

How can changes in population size be described mathematically? Ignoring immigration and emigration. Give the equation, describing each symbol.

Changes in population size can be described mathematically with many different equations



We can define a change in population size during a fixed time interval with the following verbal equation



Change in pop. Size = Births + Immigrants entering pop. - Deaths - Emigrants leaving pop. (Ignore)



 



N= population t=time then V ( the triangle - I don’t know how to make a triangle on my computer so V will be the triangle) V N- change in population and V t is the timer interval (appropriate to the life span or generation time of the species) over which we are evaluating pop. Growth. Using B for the number of births in the pop. During the time interval and D for the # of deaths, we can rewrite the verbal equation in a more concise manner



V N/ V t = B-D



In the next equation, the # of individuals that are added to or subtracted from a population during a given time (population change) interval is symbolized by R- here r represents the difference between the # of births (b) and the # of deaths (D) that occur in the time interval- thus R= B- D and we can simplify our equation by writing V N/ v t= R



 Next, we can convert our model to one in which changes in pop. Size are expressed on a per individual (per capita) basis. The per capita change in pop.  Size (.    ) represents the contribution that an average member of the pop.  Makes to the number of individuals added to or subtracted from the pop. During the time interval V t. If, for example, a population of 1,000 individuals increases by 16 individuals per year, then on a per capita basis, the annual change in pop size is 16/1,000 or 0.016. If we know the annual per capita change in population size, we can use the formula R - r.   N to calculate how many individuals will be added to (or subtracted from) a population each year. For example if       = 0.016 and the pop size is 500,



R= r.   N = 0.016 x 500=8 per year



 



Since the # of individuals added to or subtracted from the pop ( R ) can be expressed on a per capita basis as R= r.   N, we can revise our population growth equation to take this into account



V N/ V t= r.    N



 



Our equation is for a specific time interval (often one year) but many ecologists prefer to use differential calculus to express population growth as a rate of change at each instant time: dN/ dt = rN



R represents the per capita change in population size that occurs at each instant in time dt= vt but are just in shorter time intervals.

What is exponential population growth? What kind of graph would you expect to see and why?

Exponential population growth is when a population experiences ideal conditions that increase its size by a constant proportion at each instant in time. ( equation is dN/dt= rN : dN/dt represents the rate at which the population is increasing in size at each moment in time N is current pop size multiplied by r- intrinsic rate of increase)



You would expect to see a J shaped growth curve when a population is experiencing exponential growth

Define carrying capacity and list factors affect the carrying capacity.

K) the maximum population size that a particular environment can sustain



Factors that affect carrying capacity- energy, shelter, refuge from predators, nutrient availability, water, and suitable nesting sites

1. What is logistic population growth? Give and explain the mathematical



equation

 



 Logistic population growth- when a populations per capita growth rate decreases as population size approaches a maximum imposed by limited resources (k)



dN/dt= rN (K-N)/K



The equation starts with the exponential growth model and adds an expression that reduces the per capita rate of population growth as N increases. If carrying capacity is K, then K-N is the number of additional individuals the environment can support, and (K-N)/K is the fraction of K that is still available for popualtion growth. By multiplying the exponential rate of pop growth r N by (K-N0/k, we modify the change in pop size as N increases



 

what is a life history

A life history is the traits that affect an organisms schedule or reproduction and survival. Life history traits of an organism are evolutionary outcomes reflected in its development, physiology, and behavior

Semelparity

 a single reproductive episode before death- coho salmon spawn thousands of eggs in a single reproductive oppurtunity before it dies.

iteroparity

repeated reproduction- female loggerhead turtles produce four clutches totaling approximatly 300 eggs a year

Explain the concept of trade-offs in life histories and how it affects populations. Give an example.

 The concept of trade-offs in life histories is how there is a trade-off between offspring number and the amount of resources a parent can devote to each offspring. Such trade-offs occur because organisms do not have access to unlimited amounts of resources. As a result, the use of resources for one function (such as reproduction) can reduce the resources for supporting another function (such as survival)/ This affects populations because it can result in the amount of infant mortality rising if a organism produces thousands of offspring and not caring for it, rather than less offspring and caring for it. Also, the organisms that produces thousands of offspring will be able to bounce back after a environmental impact more than the organism who produces less offspring and cares for it more. For example, the white rhinoceros only produces a single calf at a time, but the care that the rhino puts into that single calf ensures that it will have long lasting fulfilling life, compared to some plants with small seeds that produce thousands of seeds only for some of them to actually root into the ground and be sustained.

Compare and contrast r and K selection – this is a key concept.

K- advantageous at high densities, living at a density near the limit of carrying capacity where competition among individuals is stronger, mature trees growing in old-growth forests= k selected species, grounded in the idea of carrying capacity



R- maximize reproductive success in uncrowded environments (low densities), maximize the intrinsic rate of increase and occurs in environments in which population densities are well below carrying capacity, individuals face little competitions, weeds growing in an abandoned agricultural field are an example of r-selected organisms, grounded in the idea of carrying capacity

 




1.  What is the difference between density-dependent and density-independent factors as a general term?

The difference between density-dependent and density-independent factors as a general term is while density independent birth or death rate does not change with population density, density dependent has a death rate that increases with population density or a birth rate that falls with rising density.

 Describe the density-dependent factors in population regulation by negative regulation

Without some type of negative feedback between population density and the rates of birth and death, a population would never stop growing. The density-dependent factors in population regulation by negative regulation is how if a population grows a high amount, it can result in high mortality of that species due to less shelter to hide from predation. Increased competition for resources, and  disease. Increased densities can cause population growth rates to decline by affecting reproduction, growth and survival.

what is population dynamics

Population dynamics is how populations can fluctuate from year to year or place to place and are influenced by many factors and in turn affect other species. For example, fluctuations in fish populations affect the populations of seabirds that eat fish.

 What causes population fluctuations? Give a few examples.

Harsh weather



Fluctuations in seasonal temperatures: hotter summer than normal, colder summer than normal



Food shortage during winter



Disease

Access to mates

What is a population cycle? Why do they occur? Give an example.

A population cycle is when populations undergo regular fluctuation (boom-and-bust cycles). They occur due to weather change, response to predators, availability of resources. An example is the roughly 10 year cycling of snowshoe hares. Lynx are the hare's predator so the lynx number might be expected to rise and fall with the numbers of hares. Due to overexploitation of predators, the hare population has a 10 year cycle .

 Define metapopulations and explain how immigration and emigration play roles in population dynamics

 a group of spatially separated populations of one species that interact through immigration and emigration.



Immigration and emigration play roles in population dynamics because it can result in a species existing in multiple places throughout an area and can decrease extinction due to being in so many different areas. If one population becomes extinct, the patch it occupied may be recolonized by immigrants from another population. 

How is the human global population changing? What accounts for this change?

The human global population is changing by growing in an unprecedented rate in the last few centuries. This change resulted from better healthcare worldwide. Now, the population growth rate is starting to slow down. This can be accounted for new diseases like aids and voluntary population control.

Describe the two scenarios that lead to population stability (zero population growth).

Two scenarios that lead to population stability is high birth rate and high death rate or low birth rate and low death rate.

What is demographic transition? Give a specific example.

A demographic transition is the movement from high birth and death rates toward low birth and death rates, which tends to accompany industrialization and improved living conditions. An example of this is in sweden the transition occurred from 1810-1975 when the birth rates finally approached death rates (end product). In Mexico, the human population is still growing rapidly meaning it is in the process of going through a demographic transition, but has not completed yet. Demographic transition is associated with an increase in the quality of health care and sanitation as well as improved access to education for woman which decreases the birth rate as woman start to get more jobs.

Describe the relationship between industrialization and population growth.

The relationship between industrialization and population growth is as a country is becoming more industrialized, the population growth will start to reach equilibrium  and stop growing due to their being less death due to increased sanitation and less birth due to woman getting access to jobs and education instead of having children.

What is age structure and why does it affect population growth?

Age structure is the relative number of individuals of each age in the population. Age structure is commonly graphed as "pyramids". Age structure affects population growth because it shows how if there is a lot of the population at a young age compared to the rest of the ages in a population, the population will grow because the people at young ages will reproduce and make the population overall bigger, but if the young population is low or comparable to the other ages of a population, the population will have slow growth or decrease because the young generation wont have enough children to go above the replacement level to keep the population growing.

 What kinds of information do age structure pyramids provide (Fig. 53.24) and what inferences can be made from these?

 The kinds of information that age structure pyramids provide is life expectancy of a population, infant mortality rates of a population, if ow how industrialized a country is, and if the population is growing, remaining stable, or decreasing. One can infer if a country is going through or finished a demographic transition based on the pyramid and how much they are growing.

Why is it important to estimate the earth’s human carrying capacity? Explain the ways scientists have tried to estimate this.

It is important to estimate the earth's human carrying capacity because we need to know at what point the earth cannot support the amount of overpopulation that humans have. Scientists have tried to estimate this by using curves like that produced by the logistic equation to predict the future maximum of the human population. Others generalize from existing "maximum" population density and multiply this number by the area of habitable land. Others base their estimates on a single limiting factor, such as food, and consider variables such as the amount of farmland, the average yield of crops, the prevalent diet and the # of caloried needed per person per day.

Define ecological footprint. Explain why is it useful when thinking about the human population size.

he aggregate land and water area required by each person, city, or nation to produce all the resources it consumes and to absorb all the waste it generates. It is useful when thinking about the human population size because it provides knowledge on how many more people can fit in a nation or the world based on the ecological footprint and how much land and energy each person uses and how much more people can be born and have food and energy before it eventually runs out.

What personal responsibility does each individual have in our own species survival?

Personal responsibility that each individual has in our own species survival is our own ecological footprint and trying to decrease because if we keep up at the pace of using things and wasting energy and waste, the current humans could lower the planet's long term carrying capacity for future generations limiting the chance of the human species survival.

Describe how community interactions are classified. List the six interspecific interactions.

 Competition, predation, herbivory, paratism, mutualism, and commensalism



They are defined according to whether they have a positive (+) or negative (-) effects on the survival and reproduction of each of the two species engaged in the interaction. A 0 indicates that a species is not affected by the interaction in any known way.

How does competition affect species within a community? Give an example

 Competition (-/-) affects species within a community because it occurs when individuals of different species compete for a resource that limits the survival and reproduction of each species. Lynx and foxes in the northern forests of Alaska and Canada compete for prey such as snowshoe hares

Use an example to explain what is meant by competitive exclusion.

 When the two closely related species Paramecium aurelia and Paramecium caudatum are grown seperatly, each population will grow in a rapid number and cut off at carrying capacity. But, when they are grown together P. caudatum became extinct showing that P. aurielia had a competitive advantage in obtaining food. This means that two species competing for the same limiting resource cannot coexist permanently in the same place. In the absence of disturbance, one species will use the resources more efficiently and reproduce more rapidly than the other.

what is an ecological niche

Ecological niche is the specific set of biotic and abiotic resources that an organism uses in its environmen

Define resource partitioning and explain how this relates to competitive exclusion.

the division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species. This relates to competitive exclusion because it makes it so the species don’t have the same niche so they don’t compete to a point where one will be extinct. This combats competitive exclusion.

Compare and contrast a fundamental niche and a realized niche

Fundamental niche- the niche potentially occupied by that species



Realized niche- the portion of its fundamental niche that it actually occupies.



Both of the niches have a chance of being occupied by a species, but only realized niche is certain that a species will actually occupy.

Describe the experiments on the spiny mouse. What was learned through these experiments?

 The experiments on tiny spiny mouse showed how if the scientists took out the nocturnal a cahirnus mouse, the  diurnal a. russatus, which is biogoically nocturnal, became nocturnal as well. This change in behavior suggests that competition exists between the species and the partitioning of their active time helps them coexist.

Define allopatric and sympatric species.

 Allopatric-occuring in different geographic areas or in isolation



Sympatric-occupying in the same geographic range

Explain character displacement of closely related species and explain what this tells us about competition.

 Character displacement of closely related species happens usually because when species that are closely related lice sympatric, one may develop different abilities than the other so they are able to live in the same place without competing to a point of competitive exclusion. This tells us that competition can be overcome by species developing different body structures that use different resources than another species they usually compete with.