ECOLOGY Honors Biology. What you will learn… 1. Ecology general overview. A. Definition B. Levels of Organization C. Abiotic vs. Biotic Factors

ECOLOGY

Honors Biology

What you will learn… 1. Ecology general overview.

A. Definition B. Levels of Organization C. Abiotic vs. Biotic Factors

2. Populations A. Definition B. Population Density C. Population Structure and Dynamics D. Determining Population Growth E. Age Structure

Communities and Ecosystems

1 A. Definition Ecology is the study of how organisms

interact with their environment and each other.

• This interaction of organisms is a two-way interaction. Organisms are affected by their environment, but by their activities they also change the environment.

1 B. Levels of Organization

• Ecology is studied on several levels:– Organism

• Ecologists may examine how one kind of organism meets the challenges of its environment, either through its physiology or behavior.

– Population• Group of individuals of the same species living in a particular geographic

area. – Community

• Consists of all the populations of different species that inhabit a particular area.

– Ecosystem• Includes all forms of life in a certain area and all the nonliving factors as

well.– Biosphere

• The global ecosystem; the sum of all the planet’s ecosystems. • Most complex level in ecology, including the atmosphere to an altitude of

several kilometers, the land down to and including water-bearing rocks under 3,000 m under Earth’s surface, lakes and streams, caves, and the oceans to a depth of several kilometers.

• It is self contained, or closed, except that its photosynthesizers derive energy from sunlight, and it loses heat to space.

1 B. Levels of Organization

1 C. Abiotic vs. Biotic Factors Abiotic components

Physical and chemical factors (abiotic) affecting the organisms living in a particular ecosystem.

Biotic components Organisms making up the community

1 C. Examples of Biotic Factors

Anything that has the characteristics of life!

Even bacteria!

Trees and grassPolar bears

Starfish

1 C. Examples of Abiotic Factors:

Solar energy Water Temperature Wind Soil composition Unpredictable disturbances

2 A. What is a population?

Population- a group of individuals of a single species

that occupy the same general area. Rely on the same resources, are influenced

by the same environmental factors, and have a high likelihood of interacting and breeding with one another.

2 B. Population Density – What is it? Population density

The number of individuals of a species per unit area or volume

For example, the number of oak trees per square kilometer (km2) in a forest or earthworms per cubic meter (m3) in forest soil

2B. Population Density- How do we measure it? In some cases, it is estimated by indirect

indicators, such as number of bird nests or rodent burrows or even droppings or tracks.

In rare cases, it is possible to count all individuals within the boundaries of the population. For example, it is possible to count the number of sea stars in a tide pool.

Instead in most cases, ecologists use a variety of sampling techniques to estimate population densities. For example, they might base an estimate of the density of alligators in

the Florida Everglades on a count of individuals in a few sample plots of 1 km2 each. The larger the number and size of sample plots, the more accurate the

estimates.

2B. Population Density- How do we measure it? To measure population density, ecologists

use a variety of sampling techniques to estimate population densities. In most cases, it is impractical or impossible to count all individuals of a population.

Sampling Techniques: Point Sampling Transect Sampling Quadrat Sampling Mark and recapture (capture-recapture)

2C. Population Structure- Dispersion Patterns

Within a population’s geographic range, local densities may vary greatly.

The dispersion pattern of a population refers to the way individuals are spaced within their area.

These patterns are important characteristics for an ecologist to study, since they provide insights into the environmental effects and social interactions in the population. Clumped Uniform Random

2C. Population Structure- Dispersion Patterns

Clumped pattern Most common in nature Individuals are aggregated in patches Often results from an unequal distribution of resources

in the environment. For example, plants or fungi may be clumped in areas where

soil conditions and other factors favor germination and growth.

Clumping of animals is often associated with uneven food distribution or with mating or other social behavior. For example, fish are often clumped in schools, which may

reduce predation risks and increase feeding efficiency. Mosquitoes often swarm in great numbers, increasing their chances for mating.

2 C. Population Structure- Dispersion Patterns

Uniform, or even, pattern Pattern of dispersion often results from

interactions between the individuals of a population. For example, some plants secrete chemicals

that inhibit the germination and growth of nearby plants that could compete for resources.

Animals may exhibit uniform dispersion as a result of territorial behavior. For example, penguins and humans

2 C. Population Structure- Dispersion Patterns Random dispersion

Individuals in a population are spaced in a patternless, unpredictable way. For example, clams living in a coastal mudflat

might be randomly dispersed at times of the year when they are not breeding and when resources are plentiful and do not affect their distribution.

Varying habitat conditions and social interactions make random dispersion rare.

2 C. Population Structure

Life Tables Used to determine the average lifespan of

various plants and animal species to study the dynamics of population growth.

http://www.ssa.gov/OACT/STATS/table4c6.html

2 C. Population Structure Survivorship curves

Graphs generated from life tables to make the data easier to comprehend.

Plot the proportion of individuals alive at each age. • Type 1- produce few offspring, take care of

their young, many survive into maturity.• Type 2- intermediate, more constant mortality

over the entire life span.• Type 3- high death rates for the very young,

mature individuals survive longer, usually involves very large # of offspring with little or no parent care

2 C. Population Structure

Three types of survivorship curves

2 D. Determining Population Growth Population Growth

The number of individuals comprising a population may fluctuate over time. These changes make populations dynamic.

A population in equilibrium has no net change in its abundance.

Population Growth = B – D + I – E• Factors that influence the number of

individuals in a population:– Birth (B) also known as natality– Death (D) also known as mortality– Immigration (I)– Emigration (E)

2 D. Determining Population Growth

The Exponential Growth Model The rate of population increase under ideal conditions.

(High Birth Rate, Low Death Rate) Gives an idealized picture of unregulated population

growth; no population can grow exponentially indefinitely.

The whole population multiplies by a constant factor during each time interval.

http://www.pbs.org/wgbh/nova/earth/global-population-growth.html

2 D. Determining Population Growth Logistic Growth Model (Carrying

Capacity) A description of idealized population growth that is slowed by

limiting factors as the population size increases. Limiting factors are environmental factors that restrict population

growth.

carrying capacity is the maximum population size that a particular environment can support or “carry”

S-shape curve 1. Exponential Growth Phase-When the population first

starts growing, population growth is close to exponential growth

2. Transitional Phase- The population growth starts to slow 3. Plateau Phase- Carrying capacity is reached and the

population is as big as it can theoretically get in its environment


Logistic Growth Curves


2 D. Determing Population Growth

Factors that appear to regulate growth in natural populations: 1. Density-dependent factors:

Competition among members of a growing population for limited resources, like food or territory.

Health of organisms Predation Physiological factors (reproduction, growth, hormone

changes) 2. Density independent factors

• Regardless of population density, these factors affect individuals to the same extent.– Weather conditions– Acidity– Salinity– Fires– Catastrophies

2 D. Determing Population Growth

Factors that appear to regulate growth in natural populations (continued): 3. Boom-and-bust cycles –

the number of individuals within the population seems to show a cyclic change.

Predator/prey relationships Changing food supply

2 E. Birth and Death Rates and Age Structure, OH MY! Human population can also be described

by age structure diagrams. These diagrams are frequently dependent on the economy and social state of the country that they are measured in.

3. Communities

A few terms you should know… Species –

A group of organisms which can interbreed with each other and able to produce a fertile offspring.

Habitat – the environment in which a species

normally lives or the location of a living organism.

3. Communities

A biological community is an assemblage of all the populations of organisms living close enough together for potential interaction.

Key characteristics of a community: a.Species diversity b.Dominant species c.Response to disturbances d.Trophic structure e. Community interactions

3a. Species Diversity

How would you define diversity? What makes a group diverse? What should be present? Any specific

quantity? What do you think should be considered when

considering a community’s diversity?


The variety of different kinds of organisms that make it up, Has two components:

1. species richness The total number of different species in the community. The more species present in a sample, the 'richer' the

sample. 2. species abundance (sometimes referred to as

“evenness”) a measure of the relative abundance of the different

species making up the richness of an area.


To give an example: we might have sampled two different fields for wildflowers.

The sample from the first field consists of 300 daisies, 335 dandelions and 365 buttercups.

The sample from the second field comprises 20 daisies, 49 dandelions and 931 buttercups (see the table below).

What would you say regarding the diversity (richness and abundance) of this community?


Both samples have the same richness (3 species) and the same total number of individuals (1000).

However, the first sample has more abundance, or evenness, than the second. This is because the total number of individuals in the sample is quite evenly distributed between the three species.

In the second sample, most of the individuals are buttercups, with only a few daisies and dandelions present.

Sample 2 is therefore considered to be less diverse than sample

3b. Dominant Species

In general, a small number of species exert strong control over a community’s composition and diversity.

Keystone species is a species that exerts strong control on community structure because of its ecological role, or niche.

Example: sea otters are a keystone predator in the North Pacific.

Sea otters feed on sea urchins, and sea urchins feed mainly on kelp, a large seaweed.

In areas where sea otters are abundant, sea urchins are rare and kelp forests are well developed.

Where sea otters are rare, sea urchins are common and kelp is almost absent.

3b. Dominant Species

Human overfishing is a problem in Alaska. As a consequence, seal and sea lions have lost their food source and have declined in population. Killer whales, therefore have also lost their food source, and now started eating sea otters. Predict what will happen as a result.

3b. Dominant Species The loss of this keystone species has

allowed sea urchin populations to increase, resulting in the destruction of kelp forests.

3c. Response to Disturbances Communities change drastically

following a severe disturbance that strips away vegetation and even soil.

The disturbed area may be colonized by a variety of species, which are gradually replaced by a succession of other species, in a process called ecological succession.

3c. Response to Disturbances

Primary succession When ecological succession begins in a virtually lifeless

area with no soil. Usually takes hundreds or thousands of years. For example, new volcanic islands or rubble left by a

retreating glacier. Often the only life-forms initially present are autotrophic bacteria. Lichens and mosses are commonly the first large photosynthesizers to colonize the area. Soil develops gradually as rocks weather and organic matter accumulates from the decomposed remains of the early colonizers. Lichens and mosses are gradually overgrown by grasses and shrubs that sprout from seeds blow in from nearby areas or carried in by animals. Eventually, the area is colonized by plants that become the community’s prevalent form of vegetations.

3c. Response to Distrurbances

Secondary succession Occurs when a disturbance has destroyed an

existing community but left the soil intact. For example, forested areas that are cleared

for farming, areas impacted by fire or floods.

3c. Response to Disturbances Primary Succession

Example: autotrophic prokaryoteslichens, mossesgrassesshrubstreesclimax communty

Secondary Succession Example: herbaceous plants woody shrubs trees

climax community


Early successional communities are characterized by a low species diversity, simple structure and broad niches

The succession proceeds in stages until the formation of a climax community. The most stable community in the given

environment until some disturbance occurs.

3c. Response to Distrurbances Are disturbances always a bad thing?

When can they be beneficial?


Small-scale disturbance often have positive effects. For example, when a large tree falls in a windstorm, it disturbs the

immediate surroundings, but it also creates new habitats. For instance, more light may now reach the forest floor, giving small

seedlings the opportunity to grow; or the depression left by its roots may fill with water and be used as egg-laying sites by frogs, salamanders, and numerous insects.

Small-scale disturbances may enhance environmental patchiness, which can contribute to species diversity in a community.

3d. Trophic Structure

The feeding relationships among the various species making up the community.

A community’s trophic structure determines the passage of energy and nutrients from plants and other photosynthetic organisms to herbivores and then to carnivores.


The sequence of food transfer up the trophic levels is known as a food chain Trophic levels are arranged vertically, and the

names of the levels appear in colored boxes. The arrows connecting the organisms point

from the food to consumer. This transfer of food moves chemical nutrients and energy from the producers up though the trophic levels in a community.


At the bottom, the trophic level that supports all others consists of autotrophs, called producers. Photosynthetic producers use light energy to

power the synthesis of organic compounds. Plants are the main producers on land. In water, the producers are mainly

photosynthetic protists and cyanobacteria, collectively called phytoplankton. Multicellular algae and aquatic plants are also important producers in shallow waters.


All organisms in trophic levels about the producers are heterotrophs, or consumers, and all consumers are directly or indirectly dependent on the output of producers


Trophic Levels: Primary producers

Mostly photosynthetic plants or algae Primary consumers

Herbivores, which eat plants, algae, or phytoplankton. On land include grasshoppers and many insects, snails, and certain vertebrates

like grazing mammals and birds that eat seeds and fruits aquatic environments include a variety of zooplankton (mainly protists and

microscopic animals such as small shrimp) that eat phytoplankton. Secondary consumers

Include many small mammals, such as a mouse, a great variety of small birds, frogs, and spiders, as well as lions and other large carnivores that eat grazers.

In aquatic ecosystems, mainly small fishes that eat zooplankton Tertiary consumers

Snakes that eat mice and other secondary consumers. Quaternary consumers

Include hawks in terrestrial environments and killer whales in marine environment.


Another trophic level of consumers are called detritivores which derive their energy from detritus, the dead material produced at all the trophic levels. Detritus includes animal wastes, plant litter, and all

sorts of dead organisms. Most organic matter eventually becomes detritus

and is consumed by detritivores. A great variety of animals, often called

scavengers, eat detritus. For instance, earthworms, many rodents, and insects eat fallen leaves and other detritus. Other scavengers include crayfish, catfish, crows, and vultures.


A community’s main detritivores are the prokaryotes and fungi, also called decomposers, or saprotrophs, which secrete enzymes that digest organic material and then absorb the breakdown products.

Enormous numbers of microscopic fungi and prokaryotes in the soil and in mud at the bottom of lakes and oceans convert (recycle) most of the community’s organic materials to inorganic compounds that plants or phytoplankton can use.

The breakdown of organic materials to inorganic ones is called decomposition.


3d. Trophic Structure A more realistic view of the trophic structure of

a community is a food web, a network of interconnecting food chains.

Food webs, like food chains, do not typically show detrivores, which consume dead organic material from all trophic levels.

3e. Community Interactions

Consider this… You’ve planted a garden in your backyard.

You see that a squirrel population and a chipmunk population has begun to inhabit the area. There reproductive patterns are similar, they eat the same food, and have similar sleeping patterns.

What do you expect to happen? Is it possible for them to cohabit the area?


Interspecific competition: If two different species are competing for the

same resource. Causes the growth of one or both populations

may be inhibited. May play a major role in structuring a

community. Examples:

Weeds growing in a garden compete with garden plants for nutrients and water.

Lynx and foxes compete for prey such as snowshoe hares in northern forests.


Intraspecific Competition: Intense competition that exists within

individuals of the same population because they compete for the exact same habitat and resources


Competitive Exclusion Principle idea: In 1934, Russian ecologist Gause studied

the effects of interspecific competition in laboratory experiments with two closely related species of Paramecium.


Competitive Exclusion Principle Experiment:

Gause cultured these protists under stable conditions with a constant amount of food added every day.

When he grew the two species in separate cultures, each population grew rapidly and then leveled off at what was apparently carrying capacity of the culture.

But when Gause cultured the two species together, one species was driven to extinction.


Competitive Exclusion Principle Conclusion: Gause concluded that two species so similar that

they compete the same limited resources cannot coexist in the same place.

One will use the resources more efficiently and thus reproduce more rapidly than the other.

Even a slight reproductive advantage will eventually lead to local elimination of the inferior competitor.


The competitive exclusion principle applies to what is called a species’ niche. In ecology, a niche is a species’ role in its

community, or the sum total of its use of the biotic and abiotic resources of its habitat.


A niche is the functional position of an organism in its environment, comprising its habitat, resources and the periods of time during which it is active. The following are included in a niche: Physical conditions – Ex. Humidity, sunlight,

temperature, salinity, pH, exposure, depth Resources offered by the habitat – Ex. Food

sources, shelter, mating sites, nesting sites, predator avoidance.

Adaptations for – locomotion, biorhythms, tolerance of physical conditions, defence, predator avoidance, reproduction, feeding.


There are two possible outcomes of competition between species having identical niches: Either the less competitive species will be driven to local extinction, or one of the species may evolve enough through natural selection to use a different set of resources. This differentiation of niches that enables

similar species to coexist in a community is called resource partioning.


Resource Partioning: It is a way in which different species can use the same

resource, such as food, without occupying the same physical location at the same point in time.

For example, different warblers eat the same caterpillar, but they occupy different positions in the tree. Two primarily occupy the area near the trunk, with the others share the edges of the branches, but at different heights. The result is the warblers do not overtly compete for food in the same space.


Predation is an interaction between species in which one species, the predator, kills and eats another, the prey.

Because eating and avoiding being eaten are prerequisites to reproductive success, the adaptations of both predators and prey tend to be refined through natural selection.


What are some ways predators can catch prey? What tools can they use? What are some essential characteristics?

3e. Community Interactions Examples of prey capturing strategies:

Most predators have acute senses enable them to locate prey.

In addition, adaptations such as claws, teeth, fangs, stingers, or poisons help catch and subdue prey.

Predators are generally fast and agile, whereas those that lie in ambush are often camouflaged in their environments.

Predators may also use mimicry; some snapping turtles have a tongue that resembles a wriggling worm, thus luring small fish.

CamouflageChemical Defense


What are some ways prey can avoid predators? What tools can they use? What are some essential characteristics?

3e. Community Interactions Predator defenses:

Mechanical defenses: such as the porcupine’s sharp quills or the hard shells of clams and oysters.

Chemical defenses: animals are often bright colored, a warning to predators; like a poison arrow-frog or a skunk.

Batesian mimicry: a palatable or harmless species mimics an unpalatable or harmful one; like the king snake mimics the poisonous coral snake

Mullerian mimicry: two unpalatable species that inhabit the same community mimic each other; like bees and wasps

Batesian Mimicry Mullerian Mimicry


Herbivory Animals that eat plants or algae Aquatic herbivores include sea urchins, snails, and some fishes. Terrestrial herbivores include cattle, sheep, and deer, and small

insects. Herbivorous insects may locate food by using chemical sensors

on their feet, and their mouthparts are adapted for shredding tough vegetation or sucking plant juices.

Herbivorous vertebrates may have specialized teeth or digestive systems adapted for processing vegetation. They may also use their sense of smell to identify food plants.

Because plants cannot run away from herbivores, chemical toxins, often in combination with various kinds of anti-predator spines and thorns, are their main weapons against being eaten.

3e. Community Interactions Herbivory

Some herbivore-plant interactions illustrate the concept of coevolution, a series of reciprocal evolutionary adaptations in two species.

Coevolution occurs when a change in one species acts as a new selective force on another species, and counteradaptation of the second species in turn affects the selection of individuals in the first species.


Herbivory Coevolution Example: an herbivorous insect (the caterpillar

of the butterfly Heliconius, top left) and a plant (the passionflower Passiflora, a tropical vine).


Herbivory Coevolution Explanation: Passiflora produces toxic chemicals that protect its

leaves from most insects, but Heliconius caterpillars have digestive enzymes that break down the toxins. As a result, Heliconius gains access to a food source that few other insects can eat.

The Passiflora plants have evolved defenses against the Heliconius insect. The leaves of the plant produce yellow sugar deposits that look like Heliconius eggs. Therefore, female butterflies avoid laying their eggs on the leaves to ensure that only a few caterpillars will hatch and feed on any one leaf. Because of this, the Passiflora species with the yellow deposits are less likely to be eaten.


Symbiotic Relationships are interactions between two or more species that live together in direct contact. Three main types:

Parasitism Commensalism Mutualism *Parasitism and mutualism can be key

factors in community structure.

3e. Community Interactions Parasitism

A parasite lives on or in its host and obtains its nourishment from the host.

For example: A tapeworm is an internal parasite that lives inside the intestines of a larger animal and absorbs nutrients from its hosts.

Another example: Ticks, which suck blood from animals, and aphids, which tap into the sap of plants, are examples of external parasites.

Natural selection favors the parasites that are best able to find and feed on hosts, and also favors the evolution of host defenses.

Tapeworm in Small Intestine

Tick on a dog


Commensalism One partner benefits without significantly affecting the other. Few cases of absolute commensalism have been

documented, because it is unlikely that one partner will be completely unaffected.

For example: algae that grow on the shells of sea turtles, barnacles that attach to whales, and birds that feed on insects flushed out of the grass by grazing cattle.

Algae on Sea Turtle Barnacles on Whale

3e. Community Interactions Mutualism

Benefits both partners in the relationship. For example: the association of legume plants and

nitrogen-fixing bacteria. Bacteria turn nitrogen in the air to nitrates that the

plants can use Another example: Acacia trees and the

predaceous ants they attract. Tree provides room and board for ants Ants benefit the tree by attacking virtually anything

that touches it.

Acacia Trees and Ants

4. Ecosystems

An ecosystem consists of all the organisms in a community as well as the abiotic environment with which the organisms interact.

Ecosystems can range from a microcosm such as a terrarium to a large area such as a forest.

4a. Ecosystems- Energy Flow Regardless of an ecosystem’s size, its dynamics involve

two processes- energy flow and chemical cycling. Energy flow: the passage of energy through the

components of the ecosystem. For most ecosystems, the sun is the energy source, but

exceptions include several unusual kinds of ecosystems powered by chemical energy obtained from inorganic compounds.

4a. Ecosystems- Energy Flow


For example, an a terrarium, energy enters in the form of sunlight. Plants (producers) convert the light energy to chemical energy. Animals (consumers) take in some of this chemical energy in the

form of organic compounds when they eat the plants. Detrivores, such as bacteria and fungi in the soil, obtain chemical

energy when they decompose the dead remains of plants and animals.

Every use of chemical energy by organisms involves a loss of some energy to the surroundings in the form of heat.

Eventually, therefore, the ecosystem would run out of energy if it were not powered by a continuous inflow of energy from an outside source.

4a. Ecosystems- Energy Flow Biomass is the term ecologist use to refer to the amount, or

mass, of living organic material in an ecosystem. Primary production is the amount of solar energy converted to

chemical energy (organic compounds) by an ecosystem’s producers for a given area and during a give time period. It can be expressed in units of energy or of mass. The primary production of the entire biosphere is 170 billion

tons of biomass per year. Different ecosystems vary considerably in their primary

production as well as in their contribution to the total production of the biosphere.

Net primary production refers to the amount of biomass produced minus the amount used by producers as fuel for their own cellular respiration. Gross production- respiration = net production (GP-R=NP)


•Tropical rainforests are among the most productive terrestrial ecosystems and contribute a large portion of the planet’s overall production of biomass.

•Even though the open ocean has very low production, it contributes the most to Earth’s total net primary production because of its huge size- it covers 65% of Earth’s surface

•Coral reefs also have very high production, but their contribution to global production is small because they cover such a small area.

4a. Ecosystems- Energy Flow Ecological Pyramids

Pyramid of Biomass Pyramid of Productivity Pyramid of Numbers

4a. Ecosystems- Energy Flow Pyramid of Biomass:

shows the relationship between biomass and trophic level by quantifying the amount of biomass present at each trophic level of a community at a particular moment in time.

4a. Ecosystems- Energy Flow Pyramid of Biomass Typical units are grams per meter


Pyramid of Production Illustrates the cumulative loss of energy with each transfer in a

food chain. Each tier of the pyramid represents one trophic level, and the

width of each tier indicates how much of the chemical energy of the tier below is actually incorported into the organic matter of that trophic level.

Note that producers convert only about 1% of the energy in the sunlight available to them to primary production.

In this idealized pyramid, 10% of the energy available at each trophic level becomes incorporated into the next higher level.

The efficiencies of energy transfer usually range from 5 to 20%. In other words, 80 to 95% of the energy at one trophic level

never transfers to the next.

4a. Ecosystems-Energy Flow

Pyramid of Production: Units can be Joules or calories

4a. Ecosystems- Energy Flow Pyramid of Numbers

shows graphically the population of each level in a food chain.

4b. Ecosystems- Chemical Cycling Chemical cycling: involves the transfer of materials within

the ecosystem. An ecosystem is more or less self-contained in terms of

matter. Chemical elements such as carbon and nitrogen are

cycled between abiotic components (air, water, and soil) and biotic components of the ecosystem.

The plants acquire these elements in inorganic form from the air and soil and fix them into organic molecules, some of which animals consume.

Detrivores return most of the elements in inorganic form to the soil and air.

Some elements are also returned as the by-products of plant and animal metabolism.

4b. Ecosystems- Chemical Cycling


Biogeochemical cycles: Water cycle Carbon cycle Nitrogen cycle Phosphorous cycle


General Model of Nutrient Cycling: 1. Producers incorporate chemicals from the abiotic reservoir

(where a chemical accumulates or is stockpiled outside of living organisms) into organic compounds.

2.Consumers feed on the producers, incorporating some of the chemicals into their own bodies.

3. Both producers and consumers release some chemicals back to the environment in waste products (CO2 and nitrogen wastes of animals)

4. Detritivores play a central role by decomposing dead organisms and returning chemicals in inorganic form to the soil, water, and air.

5. The producers gain a renewed supply of raw materials, and the cycle continues.


1 Mj

2 Mj

4 Mj

3 Mj

3 Mj

4 Mj

NUTRIENT CYCLING Mj(general model) Mj

CONSUMERS Mj

PRODUCERS Mj

NUTRIENTS AVAILABLE TO MjPRODUCERS Mj

DECOMPOSERS Mj

ABIOTIC RESERVOIR Mj

General Model of Nutrient Cycling:

Water Cycle 1.Precipitation 2.Condensation (conversion of gaseous water vapor into liquid water) 3. Rain Clouds 4. and 5. Evaporation (conversion of water to gaseous water vapor) from

ocean 6. and 7. precipitation over ocean 8. evaporation from land 9. Transpiration 10. Transpiration 11. evaporation from lakes, rivers 12. surface runof 13. infiltration (movement of water into soil) 14. Water locked in snow 15. Precipitation to land

**refer to diagrams in handout

Water Cycle

Carbon Cycle 1. Carbon in plant and animal tissues 2. fossilization (preserved remains or traces of animals, plants, and other organisms) 3. Death and excretion 4. Decomposers (breakdown organic materials to inorganic ones) 5. coal 6. photosynthesis 7. atmospheric CO2

8. Dissolving 9. combustion (burning of wood and fossil fuels) 10. diatoms (major group of algae, and are one of the most common types of

phytoplankton) 11. drilling for oil and gas 12. fossilization 13. oil and gas 14. limestone


Carbon Cycle

Nitrogen Cycle 1. Nitrogen in plant and animal tissue 2. Excretion 3. Ammonia (NH3) 4.Dead organisms 5. decomposers 6. Nitrifying bacteria (convert ammonia to nitrate) 7. nitrogen fixing bacteria (convert N2 to ammonia) 8. nitrate (NO3

-) 9. nitrate (NO3

-) available to plants 10. swampy ground 11. denitrifying bacteria (return fixed nitrogen to the atmosphere) 12. lightning (atmospheric nitrogen fixation) 13. atmospheric nitrogen (N2 gas)


Nitrogen Cycle

Documents

ECOLOGY Honors Biology. What you will learn… 1. Ecology general overview. A. Definition B. Levels of Organization C. Abiotic vs. Biotic Factors