EcologyUnit 10CHS

Organisms & Their

RelationshipsAbiotic v BioticLevels of OrganizationHabitat v NicheInteractions

Levels of Organization

0 An ecologist is a scientist that studies the interactions of living things with other living things and their surroundings

0 When ecologists study organisms in their environment they look at the levels of organization

0 When studying nature, scientists recognize 6 levels of organization

Levels of Organization0 Levels of Organization:

0 Species – a group of organisms so similar to one another that they can breed and produce fertile offspring

0 Population – a group of the same species that live in the same area0 Community – groups of different living species that live together in the

same area0 Ecosystem – the community and all of the non-living components such

as water, soil, mountains, etc.0 Biome – groups of ecosystems that have the same climate and similar

dominant communities0 Biosphere – the highest level of organization that ecologists can study

Levels of Organization

Factors in an Ecosystem0All ecosystems are made up of

living and nonliving components

0Biotic factors – are all of the living parts of an ecosystem such as plants, animals, fungi, and bacteria

0Abiotic factors – are the nonliving components such as temperature, water, wind, sunlight, and Earth’s landmasses

Factors in an Ecosystem

Biotic Factors

Abiotic Factors

ECOSYSTEM

Habitat & Niche0The habitat of an

organism is considered all of the biotic and abiotic factors where an organism livesLeopards are graceful and

powerful big cats closely related to lions, tigers, and jaguars. They live in sub-Saharan Africa, northeast Africa, Central Asia, India, and China. However, many of their populations are endangered, especially outside of Africa. (National Geographic)

Habitat & Niche0The ecological niche of

a species is made up of all the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce

Native to the Central Asian mountains, the snow leopard is a rare sight, with only about 6,000 left in the wild. They are hunted for their beautiful, warm fur and for their organs, which are used in traditional Chinese medicine. (National Geographic)

Habitat & Niche0 Think of a habitat as where a species lives and the niche as how it

lives within its habitat0 A niche includes:

0 Food – type of food, how it competes for food, and where it finds its food

0 Abiotic conditions – air temp., amount of water, etc.0 Behavior – the time of day a species is active as well as where and

when a species reproduces

Habitat & Competition0 When two species live in the same habitat it is

possible that they may require the same resources0 One species will always be better adapted to obtain a

resource over another0 The competitive exclusion principle states that

when two species compete for the same resources, one will “win” and the other will be ‘forced’ into a new niche or become extinct

Habitat & Competition0When two or more species compete for resources

(competitive exclusion) it can have 3 Effects:0 Extinction – one species puts so much pressure on the other

that it dies out0 Niche partitioning – the two species could occupy different

niches near each other not overlapping0 Evolutionary response – one species may evolve or be ‘selected

for’ different traits and evolve away from the original form

Habitat & Competition0 An ecological equivalent would be a

case where two species occupy the same niche in different parts of the world

Community Interactions

0 Competition happens when two organisms fight for similar resources such as food, space, or water0 Interspecific competition – happens when

two different species compete0 Intraspecific competition – occurs when the

same species compete

Community Interactions0 Predation – the process by which

one organism captures and eats another organism

Community Interactions

0 Symbiosis – an interaction between two or more organisms that live in direct contact with one another0 (Sym = same) (Bio = life) (Sis = together)

0 There are 3 Types of Symbiosis:0 Mutualism0 Commensalism0 Parasitism

Mutualism0 Mutualism – a symbiotic

relationship where both species benefit from the interaction

A cleaner shrimp reaches into a moray eel's mouth. The shrimp uses its claws to pick stuff off the eel's

body. That can include dead skin, tiny pieces of food, and even little creatures that can hurt the fish.

(National Geographic)

Commensalism0 Commensalism – an interaction

between organisms where one species benefits and the other does not benefit nor is it harmed

The clown fish swims among the stinging tentacles of the sea anemone for protection

and safety. The sea anemone does not benefit from this relationship nor is it harmed. The clown fish is safe in its

anemone home!

Parasitism0 Parasitism – a relationship

where one organism benefits while the other is harmed 0 Parasites keep their host

alive for days or even years while predation kills immediately

Organism Population

0 One of the main goals of all living things is to reproduce0 Studying organism population distribution and growth is an

important part of Ecology0 Population density – is a measurement of the number of

individuals living in a defined space

Organism Population0 Organism populations have varying types of

population dispersion (aka) distribution0 Clumped – living close together0 Uniform – living at regular intervals in relation to

one another0 Random – living in random places and distances

from one another0Each of these types has its own advantages and

disadvantages

Organism Population0Population Growth and the Four Factors:

0Migration (two types)0Immigration – moving “in to” an area0Emigration – moving “out of” an area

0Birth & Death0Birth rates – new organisms born cause an increase

in population0Death rates – organisms dying cause a population to

decrease

Organism Population

0 To calculate an overall population increase or decrease, you must know all four factors

Population Change

Births+

Immigration

Deaths+

Emigration–=

Population Growth0 There are Two Main Types:

0 Exponential – a population increases quickly over a short period of time

0 Logistic – a population begins with slow growth followed by rapid growth before leveling off or slower growth0A carrying capacity occurs here

Limits to Growth0 Most populations have a limit to

how large they can get0 A limiting factor is any factor that

causes population growth to decrease or stop

0 A carrying capacity is the maximum number of individuals a given area can support

Carrying capacity

Limits to Growth0 There are Two Types of Limiting Factors:

0 Density-dependent – affects a population differently depending on the size of the population0Example: a disease can have a greater effect on a larger population versus a

small population that is spread out (diseases, predation, competition, & parasitism)

0 Density-independent – affects a population in similar ways regardless of its size0Example: an earthquake will happen regardless of the size of the

population of groundhogs in a certain area (natural disasters, seasons, & unusual weather)

Energy FlowEnergy Flow

Producers v ConsumersFood Chains, Food WebsPyramid Models

Energy Flow in an Ecosystem0There are only TWO types of biotic

organisms on the planet

Producers Consumers

Energy Flow in an Ecosystem0 Producers are plants that “produce” or make

food for themselves and others0 An autotroph is an organism that is capable of

making its own food (like a tree)0 The suffix –troph refers to “food” usually in an

ecosystem

Energy Flow in an Ecosystem0 Consumers are any organism that relies upon

another organism for food (this can be animals, fungi, bacteria, protists, and even some plants)

0 The term heterotroph is used to describe this organism0 The prefix –hetero means “different”

Energy Flow in an Ecosystem

0 There are 5 types of Consumers/Heterotrophs:0 Herbivores – eat only plant material0 Carnivores – eat only animals0 Omnivores – eat both plant and animals0 Detritivores – eat dead organic matter0 Decomposers – are detritivores that break down organic matter into

simpler compounds

Types of Consumers

Detritivores as Decomposers0Decomposers are responsible for returning nutrients

back to the soil to enrich the soil for more plants to grow

Energy Flow0In any ecosystem the flow of energy is a one way path

that begins with the sun and producers0A food chain is a diagram that shows feeding relationships

and how energy flows through an ecosystem0Each “step” in the food chain is called a trophic level

0 There are 4 trophic levels shown below

Energy Flow0 The first level of organisms (producers) feeds itself as well as the

primary consumer0 The secondary consumer is next then tertiary and then quaternary

Food Webs0A food web is a

model showing the complex network of feeding relationships through trophic levels0 The “arrow” points

to the organism ‘receiving’ the energy

Food Webs0 Identify the

producers and all of the levels of consumers in the food web shown

Energy in an Ecosystem0 All ecosystems on Earth begin

with energy from the sun0 Each step in a food chain loses a

certain amount of energy from the system

0 Most energy loss is in the form of heat loss from the ‘system’

Energy in an Ecosystem

0 When you eat food the energy rich molecules in the food are used for growth, maintenance, and movement 0 The majority of the energy in foods is used to keep the body at a

healthy temperature0 The body is not perfect at using everything that you eat so you

must get rid of the unused portion as waste0 An energy pyramid is a diagram that compares energy used by

producers and consumers

Energy in an Ecosystem0 In any ecosystem there is biomass0 Biomass – is the measure of the total dry mass of organisms in a

given area0 In an energy pyramid it shows that only 10% of the energy is

actually available to be transferred from one organism to the next

Energy in an Ecosystem0A biomass pyramid is a

diagram showing the amount of biomass found at each trophic level in an ecosystem

0A pyramid of numbers shows the actual numbers of individual organisms at each trophic level in an ecosystem0 In most cases both pyramids

must have a much larger lower trophic level to support the ones above them

Cycles of MatterWater Cycle

Carbon CycleNitrogen Cycle

Phosphorous Cycle

Cycling of Matter

0 Elements, chemical compounds, and other forms of matter are passed from one organism to the next on our planet

0 The biogeochemical cycle is the cycle that describes how nutrients and water are recycled in the biosphere0 The four we will cover: Water, Carbon, Nitrogen, and

Phosphorous

The Water Cycleaka the “Hydrologic Cycle”

0 Terms you should know for the Water Cycle:0 Evaporation – process by which liquid water is changed into a gas0 Transpiration – water evaporation through the leaves of plants

The Water Cycleaka the “Hydrologic Cycle”

0 Terms you should know for the Water Cycle:0 Condensation – process by which gaseous water forms liquid

water0 Precipitation – the return of water back to the Earth (aka -

rainfall)0 Seepage – process where liquid water soaks or seeps into the soil

or ground becoming groundwater0 Runoff – when liquid water flows down a hillside, mountain or

slope to sea level

The Water Cycle

Where do we get our Water?

How much fresh water is there?(approximately)

The Carbon Cycle0 Carbon, element 6 on the Periodic Table, is considered the

“element of life”0 Carbon is found in all living organisms on Earth0 The most common exchange of Carbon is between plants and

animals though there are Four Main Ways Carbon is recycled in the Biosphere

The Carbon Cycle0 The Four ways Carbon is recycled:

0 Biological processes like photosynthesis & respiration0 Geochemical processes such as volcanic activity0 Mixed biogeochemical like dead organisms being compressed over

time forming fossil fuels0 Human activities such as burning of fossil fuels, forests, and mining

The Carbon Cycle

The Carbon Cycle

The Nitrogen Cycle0 Nitrogen gas is the most abundant gas in our atmosphere at

78% 0 It is a binary molecule consisting of two ‘bonded’ Nitrogen atoms

(N2)

0 Nitrogen is an essential element in the formation of proteins0 Plants cannot absorb Nitrogen gas directly so they need help

The Nitrogen Cycle0 Bacteria is the key to making Nitrogen available for plant use!

0 Bacteria in the soil convert Nitrogen gas into Ammonia (NH3)

through a process called nitrogen fixation0 Different types of bacteria convert the Ammonia into nutrients for

plants (nitrates and nitrites)0 Nitrates are taken into plants where they convert them into amino

acids and proteins

The Nitrogen Cycle

The Nitrogen Cycle

0 A third type of bacteria converts the nitrates back into atmospheric

Nitrogen (N2 gas) in a

process called denitrification

The Phosphorus Cycle0 Phosphorus, element # 15 on the Periodic Table, is an essential

element to living organisms0 Phosphorus helps to form the important molecules DNA & RNA

that contain the genetic materials critical for all living things on the planet

0 Phosphorus is unique in that it does not enter the atmosphere0 It is found mainly in land sediments like rock and ocean

sediments

The Phosphorus Cycle0 In rocks and minerals phosphorus exists as inorganic

phosphate and is gradually “released” after erosion of sediments

0 Phosphates are absorbed by plants through their roots and the plant binds it into organic compounds that are passed to consumers when they eat the plants0 This is the only way that Phosphorus can enter the biological

systems!

The Phosphorus Cycle

SuccessionDestruction of EcosystemsPrimary v Secondary

Ecological Succession0 Occasionally an ecosystem suffers a

tragic event that kills all life0 Succession – the sequence of

biotic changes that regenerate a damaged community or a ‘new’ area

Ecological Succession0 Primary succession occurs when a new area is available for

colonization of species0 The pioneer species is the first species to colonize an area of primary

succession0Mosses, lichens, and other primitive plants take root into rock and break it

down over a long period of time into the first soil

Ecological Succession0 Secondary succession – regenerates a

community quicker than primary and usually follows a natural disaster

Sample Test Question0 Many lakes in the U.S. have received large amounts of

nutrients, such as nitrogen and phosphorus, as a result of pollution from farms and industry. This pollution causes rapid and massive increases in some lakes’ algae population. This gradually depletes oxygen supply, killing many organisms. What is the most logical explanation for the rapid growth of algae?

Sample Test Question (answers)0 A) The increased nutrients led many organisms to

emigrate0 B) The increased nutrients supported the

population growth of algae0 C) The increased nutrients allowed algae to

outcompete other species0 D) The increased nutrients caused algae to

immigrate

Human ImpactRenewable and Nonrenewable resourcesGlobal Warming

Greenhouse GasesPollution of air and water

Human Impact

0 In the late 1700’s an economist by the name of Thomas Malthus stated0 “the human population is growing faster than the Earth’s

resources can support”0 Naturally, the rest of the world didn’t believe these

claims0 The world’s population was around 1 billion people

worldwide at this time

Human Impact0 Scientists tried to predict human population growth and

vastly underestimated it!0 Today we have gone past the predicted carrying capacity

with a world population of over 6 billion!0 Carrying capacity – the maximum number of individuals

that the environment can normally and consistently support

Human Impact0 Several human “advancements” have made it possible for

the human population growth explosion!0 Technology0 Agriculture0 Transportation0 Medical advancements0 Sanitation

Human Impact0 Oil and Coal

0 These natural resources are what humans have relied upon for power for the last 258 years

0 Oil and coal are considered nonrenewable resources 0Nonrenewable resources – resources that are

used faster than they are replenished

Human Impact0 If humans continue at the rate of 77 million

barrels of oil per day (and growing) we will quickly approach or exceed our carrying capacity!

0We must make a choice to invest in renewable energy technology if we wish to survive and preserve a planet capable of supporting life0 Renewable energy – resources that cannot be

used up or replenish themselves regularly

Human Impact0 Water is considered a renewable resource because of

annual rains and snow ‘returning’ water back to the earth0 Humans are finding ways to make water a nonrenewable

resource by polluting water sources and overuse!

Human Impact0 Humans need resources in order to survive0 There is a problem when people need too much! 0 An ecological footprint is the amount of land and

resources necessary to maintain an individual0 Maintenance includes: food, water, shelter, health,

energy, and waste

Human Impact0 What is Global Warming?

0 The trend of an increasing global temperature0 What contributes to Global Warming?

0 Our earth is protected by a thin layer of atmosphere from outer space

0 Greenhouse gases are certain gases that become “trapped” by the ozone around our planet0Gases like CO2, Methane CH4, and water vapor

Global Warming

Animal Adaptations and BehaviorBehavior

Mechanical DefensesChemical Defenses

ANIMAL BEHAVIORo Behavior is defined as anything an animal does in

response to stimuli in its environment.o Examples: o A squirrel gathering nuts and acorns in the

autumn is a behavior that is stimulated by shorter days and colder weather.

o Gathering food for themselves and their young, caring for their young, avoiding predators, seeking shelter, and finding a mate are important behaviors to the survival of many animals.

INSTINCTIVE AND LEARNED BEHAVIORS

o Instinctive Behaviors are those that are determined by inheritance. o This would be organisms expressing behavioral patterns

that are genetically controlled as opposed to behavior that has been previously learned in the organisms lifetime.

o Learned Behaviors are a result of previous experiences of an animal that modifies their current behavior.

INSTINCTIVE BEHAVIOR

o Inherited/Innate Behavioro Instinctive Behavioro Territorial Behavioro Migratory Behavior

INHERITED/INNATE BEHAVIOR

o Inherited/Innate Behavior: o Inheritance plays an important role in an animal’s

behavior. o An animal’s genetic composition determines how it

responds to stimuli. (Reflexes)o An animal’s hormonal balance, in combination with its

nervous system, affects how sensitive an animal is to stimuli.

o Inherited behavior of animals is also known as innate behavior.

o It includes both automatic responses and instinctive behaviors.

INSTINCTIVE BEHAVIORo Instinctive Behavior:

o Instincts are a complex pattern of innate behaviors. o Instinctive behaviors may take longer than reflexes and may be

a combination of behaviors. o For example, an animal’s courtship behavior is instinctive.

Animals will recognize certain behaviors exhibited by members of the same species. Each species has its own specific courtship behaviors. o The male and female black-headed gull dance in unison

side by side and turn their heads away from each other. The female taps the male’s bill and he gives her a regurgitated fish. Then the courtship is over and the pair will mate.

o Different species of fireflies flash distinctive patterns of light. The female will respond only to the male that exhibits the species-correct flashes.

ANIMAL COURTSHIP PATTERNS

TERRITORIAL BEHAVIORo Territorial Behavior:

o A territory is a physical space that contains the breeding grounds, feeding area, shelter, or potential mates of an animal.

o Animals that have territories use different behaviors to defend their space against an animal of the same or different species.

o This is a way to reduce conflict, control populations, and decrease competition.

o Aggression is another behavior exhibited by animals to fend off predators and competitors. o It is a way to protect young and to protect food sources.o Animals of the same species will not usually fight to the

death. Usually it will be the stronger animal that will stop the fighting when the weaker animal shows signs of submission.

TERRITORIAL BEHAVIOR

MIGRATORY BEHAVIORo Migratory Behavior:

o Migration is the instinctive, seasonal movement of a species.

o Over half of the birds that nest in the United States fly south for the winter. o Many head to South America where food is more

abundant during the winter months. Then they fly north in the spring to breed.

o Animals use various environmental cues to navigate during migration. o Scientists believe that some species use

geographical clues such as mountain ranges. o Other species use the Earth’s magnetic field.

MIGRATORY BEHAVIOR

LEARNED BEHAVIOR

o Habituationo Imprintingo Mechanical Defenseo Chemical Defense

HABITUATION

o Habituation:o Learned behavior that occurs when an animal is

repeatedly given a stimulus that is not harmful and does not have a negative impact on the animal.

o Examples:o Feral horses learn to allow people to ride them. o Deer have learned to come into yards to feed with

no fear of people or barking dogs.

IMPRINTINGo Imprinting:

o A process whereby a young animal follows the characteristics of his/her mother after hatching

o Examples:o A young chick after hatching can follow his/her

mother and adapt to the environment where his/her mother goes, and also the movement of his/her mother. Is like doing what the mother does.

o A young goose after hatching can follow its future mating partner and when gets matured it will start to mate with its partner due to sexual behavior it imprinted.

ADAPTATIONS FOR DEFENSE

o Most species of plants and animals have adaptations that serve as a defense against a predator. They fall into two categories: o Mechanical Defenseo Chemical Defense

MECHANICAL DEFENSE

o Mechanical Defense:o Incorporated into the physical structure of the organism

o Examples: claws, sharp ivory tusks, stingers, shells, camouflage, disruptive coloration, and countershading

CHEMICAL DEFENSE

o Chemical Defense:o occurs when the animal produces stinging sensations,

paralysis, poisoning, or just a bad taste.

Plant Responses and AdaptationsTropismsPlant Hormones

Adaptations

0 Plants possess mechanisms that enablethem to respond to their environment. These responses are known as tropisms

0 There are several types of tropisms:

Geotropism or gravitropism—a plant’s response to gravityPhototropism—a plant’s response to lightThigmotropism—a plant’s response to touch

TROPISMS

GEOTROPISM/GRAVITROPISM

o Geotropism or gravitropism is the response of seedlings to the force of gravity.

o It is important when seeds are sprouting. o Geotropism causes the roots to grow downward and the

stems to grow upward, no matter what the position of the seed when it is planted.

PHOTOTROPISM

o Phototropism is the ability of the plant to respond to light.

o If a plant is placed near a window or another light source, the plant will grow in the direction of the light source.

o A phototropic response can happen so quickly that even a seedling will respond within a few hours.

THIGMOTROPISMo Thigmotropism is the response of a plant to touch.

o Climbing plants, ivy, and vines use thigmotropism in order to find their way up or around a solid object for support.

o It is also used by some plants for protection.

TYPES OF HORMONES

o Auxins:

o Responsible for regulating phototropism in a plant by stimulating the elongation of cells. The cells on the auxin-rich shaded side of a stem will grow longer than the cells on the other side, causing the stem to bend toward the light. High concentrations of auxin help promote the growth of fruit and minimize the falling off of fruit from the plant. When auxin concentrations decrease in the autumn, the ripened fruit will fall. The plants will begin to lose their leaves

TYPES OF HORMONES

o Gibberelins:

o Growth hormones that cause plants to grow taller. o They also increase the rate of seed germination and bud

development. o There are certain tissues in the seeds that release large

amounts of gibberellins to signal that it is time to sprout.

TYPES OF HORMONES

o Abscisic Acid :

o Inhibits plant growth and cell division during times of stress, such as cold temperatures or drought.

o scientists have found that it is the balance of different hormones that determines the plant growth, rather than one hormone by itself.

EXAMPLES OF PLANT ADAPTATIONS

o Adaptations help plants survive adverse conditions in their environmento Seeds of many plants will go dormant in unfavorable

conditions. o The leaves of conifers such as pine trees have a waxy

coating over them to reduce evaporation and to conserve water.

o The bark on conifers is thick, helping to insulate the tissues from fire.

o The branches of the conifers are flexible, allowing for them to bend instead of break under the weight of ice and snow

EXAMPLES OF PLANT ADAPTATIONS

o Adaptations for reproductiono flowers can be pollinated in many ways including wind,

insects, birds, or other animals.o Maple trees produce seeds that are shaped like

wings and are carried over long distances by the wind.

o Some plants produce seeds that have hooks or barbs on them that attach to the fur of passing animals.

o Many flowers are brightly colored and fragrant, to draw attention of insects that aid in pollination. Pollen will rub off on the insect and then is carried to another flower.