ECOLOGYTECH BIOLOGY VERSION

BIO.B.4

ECOLOGY

Ecology – the study of interactions among and between organisms and their environment

ORGANIZATIONAL GROUPS

Levels of Organization (small to large) Species – group of organisms that

can breed and produce fertile offspring

Populations – groups of the same species that live in the same area

Communities – groups of different populations (therefore different species) that live in the same area

Ecosystem – all of the organisms that live in a particular place, together with their nonliving environment

Biome – a group of ecosystems that have the same climate and similar dominant communities Examples:

Biosphere – part of Earth in which life exists including land, water, and air.

Ecological Levels of Organization

The World’s Major Land Biomes

ENERGY FLOW THROUGH AN ECOSYSTEM

Sunlight is the main source of energy for life on Earth.

Less than one percent of the sun’s energy that reaches the surface is used by living thing

Autotrophs (producers) – organisms that use either light energy or inorganic chemicals make their own food

Photosynthesis – process in which organisms use light to make their own food (sugar) Examples: plants, algae, some bacteria and some protists

Chemosynthesis - process in which organisms use inorganic chemicals to make food Examples: bacteria which live in volcanoes, hot springs, and deep-sea vents

Heterotrophs (consumers) – organisms that must eat food for their energy and cannot make their own food Herbivores – eat mostly plants

Examples Carnivores – eat mostly animals

Examples Omnivores – eat both plants and

animals Examples

Decomposers – break down organic material Examples

Feeding Relationships Food Chain – series of

steps in which organisms transfer energy by eating or being eaten

Food web – links all of the food chains in an ecosystem

Trophic Level – each step in a food chain or food web

What eats what? This is the order that energy flows through an ecosystem: Producers Primary (first) consumers Secondary (second)

consumers Tertiary (third) consumers

Arrows point the direction the energy or food flows (from food to “eater”).

Section 3-2

A Food Web

Make your own food web

ENERGY PYRAMID

Energy Pyramid - shows the relative amount of energy available at each trophic level.

Ten Percent Rule - only about 10% of energy available within one trophic level is transferred to next level Why this inefficiency?

Most of the energy that an organism uses does not make it into the organism that eats it.

Energy in feces, energy used in metabolism, and energy converted to heat does not make it to the next trophic level.

NOT ALL OF THE CATERPILLAR’S FOOD IS CONVERTED INTO BIOMASS OR POTENTIAL ENERGY FOR A PREDATOR. SO THE BIRD THAT EATS THIS CATERPILLAR WILL NOT GET ENERGY FROM THE CATERPILLAR’S FECES, OR THE ENERGY THAT WAS USED BY THE CATERPILLAR.

ECOLOGICAL TERMS

Biotic – biological (living) factors that affect an ecosystem

Abiotic – nonliving (physical) factors that affect an ecosystem

Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2Abiotic and Biotic Factors

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Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2Abiotic and Biotic Factors

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Niche – full range of physical and biological conditions in which an organism lives and the way the organisms uses those conditions

Bay-Breasted WarblerFeeds in the middlepart of the tree

Yellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches

Cape May WarblerFeeds at the tips of branchesnear the top of the tree

Spruce tree

Section 4-2Figure 4-5 Three Species of Warblers and Their Niches

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COMMUNITY INTERACTIONS

Competition—an interaction in which organisms of the same or different species attempt to use a resource in the same place and at the same time.

Predation—an interaction in which one organism captures and feeds on another animal

Symbiosis – a relationship in which two species live closely together Three types of symbiosis:

Mutualism = + + (both benefit) Examples:

Commensalism = + 0 (one benefits, other little or no benefit)

Examples: Parasitism = + - (one benefits, other harmed)

Examples:

MATTER CYCLES Unlike the one-way flow of energy,

matter is recycled within and among ecosystems

Biogeochemical cycles pass molecules around again and again

The Cycles Water Cycle Carbon Cycle Nitrogen Cycle Phosphorus Cycle

The Nitrogen Cycle

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Ecological Succession – a series of changes in a community over time in response to natural and human disturbances As changes occur, older inhabitants die

out and new organisms move in. Primary Succession

Occurs where there is no soil After a volcanic eruption Bare rock exposed by glaciers moving

Changes in an Ecosystem

Pioneer Species – the first species to populate an area (ex. lichens)

Lichens (a symbiotic organism between a fungus and an alga) can grow on bare rock.

Lichens release chemicals that dissolve and break down rock thus making soil.

Once there is soil, other organisms come in like mosses and small plants and animals soon follow. Why do animals come after plants?

Secondary Succession Occurs when life is removed without destroying the soil

Plowing, fire, deforestation, drought, etc. can all spark secondary succession

Occurs faster than primary succession. Why?

NATURAL AND HUMAN DISTURBANCES

Global Warming Ozone depletion Nonnative species Invasive species Water, soil, and air pollution Habitat destruction (fire, deforestation,

etc) Oil spills Salinization of soil Mining

NATIVE SPECIES OF PLANTS AND ANIMALS IN PENNSYLVANIA

http://www.whitetailbsa.org/whitetail.jpg

http://www.netstate.com/states/symb/flowers/images/mountain_laurel.jpg

http://projects.juniata.edu/currents/kids/Brooktrout.jpg

INTRODUCED SPECIES OF PLANTS AND ANIMALS IN PENNSYLVANIA

http://www.fish.state.pa.us/pafish/raintrtm.jpg

http://www.hort.purdue.edu/ext/senior/fruits/images/large/walnutenglishtree.jpg

http://ohric.ucdavis.edu/photos/fullsize/Japanese-maple.jpg

INVASIVE SPECIES OF PLANTS AND ANIMALS IN PENNSYLVANIA

http://www.forestry.ky.gov/NR/rdonlyres/DB6C6A0E-9E0D-4014-94FE-26B82E991890/0/PurpleLoosestrife2.jpg

http://wihort.uwex.edu/Phenology/GypsyMoth.html

http://www.pgc.state.pa.us/pgc/lib/pgc/wildlife/feral_swine/hogs3_closeup.jpghttp://plainfieldtrees.blogspot.com/2007/08/ailanthus-altissima-tree-that-grows-in.html

POPULATION BIOLOGY

Understanding the numbers

POPULATION GROWTH CURVES

Exponential Growth (J) – highest rate of reproduction under ideal conditions

Logistic growth (S) – occurs when a population’s growth slows or stops following a period of exponential growth Carrying capacity – maximum

number of individuals in a population that the environment can support

UN Projections for World Human Population Levels

Present-2100