LIVING THINGS AND THE ENVIRONMENT

Prentice Hall

Chapter 21

DEFINE HABITAT. INCLUDE THREE BASIC THINGS

ORGANISMS GET FROM THEIR HABITAT AND TELL

WHY THEY NEED THOSE THINGS.

Habitat: the environment (forest, grassland, desert, tundra, etc.) where living things obtain what they need to live, grow, and reproduce.

BASICS:

1. food to live & grow

2. water to live & grow

3. shelter to live and reproduce

DEFINE BIOTIC FACTORS AND DESCRIBE

THE BIOTIC FACTORS FOUND IN THE HABITAT OF

A PRAIRIE DOG.

The living parts of a habitat – the organisms,

populations, and communities.

In a prairie grassland, this includes grass

and other plants; seeds and berries; hawks,

ferrets, sage grouse, bison, rattlesnakes,

badgers, and eagles.

Worms, fungi, and bacteria are also biotic

factors found in the prairie dog habitat.

LIST AND DESCRIBE THE FIVE MAIN

ABIOTIC FACTORS OF AN ECOSYSTEM.

WATER makes up 65% of the bodies of most organisms and is needed to carry out life processes including photosynthesis and cellular respiration.

SUNLIGHT provides the energy for photosynthesis, and therefore helps begin most food chains

OXYGEN is required by most living things to carry out life processes. For land animals, it is obtained from the air which is about 20% O2. Aquatic organisms require dissolved oxygen.

TEMPERATURE has a major impact on ecosystems. The degree of heat or cold partly determines which plants and animals can survive in an area.

SOIL is a mixture of rock fragments, nutrients, air, water, and the decaying remains of living things- along with bacteria and fungi. The type of soil largely determines which plants can grow in an area.

SUMMARIZE THE TWO PARTS OF EVERY

ENVIRONMENT:

1. BIOTIC: all the LIVING factors in an

environment

2. ABIOTIC: all the NON-LIVING factors in an

environment (physical factors - such as water,

soil, light, and temperature that affect

organisms living in a particular area)

HOW IS AN ENVIRONMENT ORGANIZED?

WHAT ARE THE LEVELS OF ORGANIZATION?

ORGANISMS- Individual living things

POPULATIONS – same species living together in the same place at the same time

COMMUNITY – all the Living populations in a region

ECOSYSTEM – living communities along with their non-living (abiotic) surroundings

BIOME – group of land ecosystems with similar climate and organisms. Ex.: Rainforest, Desert, Prairie, Deciduous Forest, Tundra. See p. 758.

BIOSPHERE - the global sum of all ecosystems.

It can also be called the ZONE of LIFE on EARTH

* 1-3 are strictly BIOTIC; Interactions between biotic and abiotic components occur at levels 4-6 of an environment

HOW ARE THE LEVELS OF THE ENVIRONMENT

CONNECTED?

As we move to higher levels of organization,

the levels include more and more living

things, types of habitats, and complexity.

DEFINE POPULATION:

A population is a group of individuals of the

same species that live together in the same

area at the same time.

Examples: a population of Great Horned Owls,

prairie dogs, sage grouse, bison, etc.

DEFINE COMMUNITY:

Consists of all the populations of different species (plants, animals, protists, bacteria, fungi) that live and interact in an area

DEFINE ECOSYSTEM:

Is made up of a community of organisms along

with abiotic factors

DEFINE ECOLOGY:

the study of how living things interact with each

other and with their environment

ECOLOGY

LIST AND DESCRIBE FIVE METHODS OF

DETERMINING THE SIZE OF A POPULATION.

1. Direct Observation: Locate, count, and tally organisms you are studying

2. Indirect Observation: Calculate numbers by signs of organisms, such as nests, tracks, scat (droppings), or sounds (bird or whale vocalizations)

3. Sampling: Calculate an estimate based on a sample density of organisms in a small area (Ex: 1 m2), and multiply times the number of these units in the study area.

4. Mark-and-Recapture: Mathematical calculation of population size based on capturing, marking, and later re-capturing organisms

5. PHOTOGRAPHY: WEB CAMS, MOTION SENSOR REMOTE CAMERAS (trail cameras), STILL PHOTOS

CHANGES IN POPULATION SIZE

If birth rate › (is greater than) death rate,

population size increases.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

If death rate › (is greater than) birth rate,

population size decreases.

DEFINE IMMIGRATION:

Moving into a population

Some Canada geese which used to migrate north

for the summer now stay in locations farther south

year round,

And additional former migrants might immigrate to

join these local populations

DEFINE EMIGRATION:

Leaving a population

If food is scarce, members of an antelope herd

may wander off in search of better grassland

for grazing. If they are permanently separated

from the original herd, they will no longer be

members of that population. They will have

emigrated to a new territory.

DEFINE POPULATION DENSITY AND INCLUDE

THE EQUATION TO ILLUSTRATE.

Number of individuals of a species in a given area:

POPULATION = NUMBER OF INDIVIDUALS

DENSITY UNIT AREA

Example: If you counted 20 monarch butterflies in a garden measuring 10 square meters, the population density would be 20 monarchs per 10 m2 ,

or 2 per sq. meter.

DEFINE LIMITING FACTORS AND DESCRIBE FIVE

EXAMPLES.

Definition: environmental factors that cause a population to decrease; any needed resources that can become scarce and result in competition

–OR- abiotic conditions that can influence the size of a population - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1. FOOD- Lack of food could mean starvation for some

2. WATER- Dehydration is deadly!

3. LIVING SPACE – Loss or reduction of space or territory makes it less likely that organisms

will reproduce

4. WEATHER – Extremes of temperatures can be deadly, and floods can wash away nests and burrows.

5. HUMANS often impact animal and plant populations. When humans develop land for houses and

buildings, they cut down trees and change animal and plant habitats. Some animals, like the raccoon

and the skunk, can adapt, but other animals can't adapt and their populations are affected.

6. COMPETITION for resources, PREDATION, or DISEASES

EXPLAIN CARRYING CAPACITY:

the largest population an area can

sustain over a long period of time

ANY CHARACTERISTIC

THAT MAKES AN

INDIVIDUAL BETTER

SUITED TO ITS

ENVIRONMENT MAY

EVENTUALLY BECOME

A COMMON TRAIT

THROUGH THIS

PROCESS.

NATURAL SELECTION

NICHE – is the role of an organism in its habitat, or how it makes its “living,”

– this includes the type of food it eats, how it obtains the food, and which other organisms use it as food- is its . . .

A niche is the role of a particular species --

what it does -- within its habitat. No two

species perform precisely the same role in a

particular habitat, at least not for long. If they

do, competition for food and a place to live

results, and one species eventually excludes

the other.

EXPLAIN HOW THREE DIFFERENT SPECIES OF WARBLERS CAN

HAVE 3 DIFFERENT NICHES ALL IN ONE TREE.

By feeding in different areas of a spruce tree,

the birds avoid competing for food.

The Cape May Warbler feeds at the top;

the Bay-Breasted Warbler feeds in the middle;

the Yellow-Rumped Warbler feeds in the lower part and the bases of the middle branches.

DEFINE COMPETITION. INCLUDE EXAMPLES OF COMPETITION FOR FOOD, WATER, SHELTER, SPACE, OR SUNLIGHT.

One of the three major types of interactions among living things,

competition is the struggle between organisms to survive as they attempt to use the same limited resource.

DEFINE PREDATION. INCLUDE “PREY” IN YOUR

EXPLANATION.

interaction in which one organism (the

predator) kills another for food (the prey)

HOW DOES PREDATION AFFECT POPULATION SIZES?

Populations of predators and prey rise and fall in

related cycles.

Too many predators = drop in prey populations.

Lack of food then causes predators to decline.

Too few predators = increase of prey populations.

LIST AND ILLUSTRATE EFFECTIVE ADAPTATIONS

USED BY PREDATORS AS STRATEGIES TO

LOCATE &/OR KILL PREY.

Speed – to out-run, out-swim, or out-fly prey

(cheetah)

Poison – to stun, immobilize, or kill prey

Sticky substances to snare insects

Light-sensitive eyes that see well in low light (owls)

Echolocation: Bats, whales, & dolphins use sound

waves to pinpoint location of prey

Camouflage to avoid being noticed by prey

Group cooperation for hunting

LIST AND ILLUSTRATE EFFECTIVE

ADAPTATIONS USED BY PREY ANIMALS AS

DEFENSE STRATEGIES.

Speed

Poisons (stinging tentacles of jellyfish)

Offensive smells (skunk spray)

Mimicry – caterpillar that looks like viper

False coloring – False eyespots on wings of moth

Protective covering – pangolins, armadillos

Camouflage – walking leaf insect

Warning coloration – the bright colors of certain insects, reptiles, and amphibians warn that they are poisonous

DEFINE SYMBIOSIS:

A very close long-term association between two or more species. Thousands of these relationships are found in nature and they are classified according to the impact the association has on the species involved.

DEFINE

MUTUALISM,

COMMENSALISM

& PARASITISM IN

THE SPACE

PROVIDED ON THE

CHART.

MARK A “+” “-“ OR “0”

IN EACH SPACE UNDER

THE HEADINGS FOR

SPECIES A AND

SPECIES B TO

INDICATE HOW EACH

IS AFFECTED.

NEXT, PROVIDE

CLEAR

EXAMPLES FOR

EACH OF THE THREE

TYPES OF

SYMBIOSIS.

RELATIONSHIP DEFINITION -

TYPE OF SYMBIOSIS SPECIES “A”

& EXAMPLES

SPECIES “B”

& EXAMPLES

Mutualism:

both species benefit

+

Saguaro

Cactus

gets pollinated

+

Long-eared bat

Gets food

Commensalism: one species benefits; the 2nd

species is neither helped nor

harmed

+ Red-tailed hawk

Gets good nest site

in region without

trees

0 Saguaro

Cactus

Not affected

Parasitism: the parasite benefits

and the host is

harmed

+

(parasite) Tapeworm or tick

Gets food

-

(host) Dog or human

Is weakened or

made sick

THREE TYPES OF SYMBIOSIS

DEFINE SUCCESSION: (NATURAL SUCCESSION)

the series of predictable changes in vegetation

that occur in a natural community over time

DEFINE PRIMARY SUCCESSION

Primary succession is the slow series of

changes in plant life that occurs in areas

where . . . no soil or organisms are present, such as a new island formed by the eruption of

an undersea volcano or an area of rock

uncovered by a melting sheet of ice (retreating

glacier).

DESCRIBE AND ILLUSTRATE THE STAGES OF

PRIMARY SUCCESSION.

WHAT ARE PIONEER SPECIES AND HOW

DO THEY ARRIVE AT THE LOCATIONS THEY

COLONIZE?

Pioneer species are the first organisms to

populate a bare area.

They are often carried by wind or water.

Lichens and mosses are often among the

first to colonize

WHAT ARE LICHENS ? AND HOW DO THEY MANAGE TO LIVE ON THE SURFACE OF

ROCKS?

Lichens are a combination of fungi and algae growing in a symbiotic partnership.

The fungal part dissolves the minerals on rocks to extract nutrients.

The algal part photosynthesizes to make food for the lichen.

Observe LICHENS at stereoscope and

make a detailed, colored drawing ABOVE

at 10x or 20x magnification.

EVENTUALLY, SUCCESSION MAY LEAD TO

A STABLE COMMUNITY THAT DOES NOT

CHANGE SIGNIFICANTLY UNLESS . . .

the ecosystem is disturbed

(by nature or by human actions)

WITH PRIMARY SUCCESSION, HOW LONG

MIGHT IT TAKE TO REACH A CLIMAX

COMMUNITY OF ORGANISMS GROWING IN

FERTILE SOIL WITH MATURE PLANTS?

It can take centuries to mature to this state—

often called a climax community!

DEFINE SECONDARY SUCCESSION:

The series of changes that occur in an area

after the ecosystem has been disturbed.

Unlike primary succession, secondary

succession occurs in a place where an

ecosystem currently exists.

DESCRIBE EXAMPLES OF NATURAL

EVENTS THAT MAY DISTURB AN

ESTABLISHED COMMUNITY AND LEAD

TO SECONDARY SUCCESSION.

Fires caused by lightning,

hurricanes,

tornadoes,

floods,

mudslides,

tsunamis,

earthquakes

WHAT KINDS OF HUMAN ACTIVITIES CAN

DISTURB AND ALTER ECOSYSTEMS?

Human activities such as

farming,

housing development,

clear-cut logging,

strip-mining ,

mountain top removal mining–

or even abandoning fields that were once

cultivated –

can set the stage for secondary succession.

DESCRIBE SECONDARY SUCCESSION. INCLUDE

DIAGRAMS, EXPLANATIONS, AND EXAMPLES AT EACH STAGE.

WHAT TWO “INGREDIENTS” ARE NECESSARY

FOR SECONDARY SUCCESSION TO OCCUR?

1. SoiL

2. Organisms