Objectives:
A.
Interactions and Interdependence a.
Ecology—the study of interactions between organisms and their environment b.
Coined in 1866 by German biologist Ernst Haeckel
B.
c.
Biosphere—contains the combined portions of the planet in which all life exists, including land, water, and air, or atmosphere.
Levels of Organization a.
Species—group of organisms so similar to one another that they can breed and produce fertile offspring b.
Populations—groups of individuals that belong to the same species and live in the same area c.
Communities—assemblages or different populations that live together in a defined area d.
Ecosystem—collection of all the organisms that live in a particular place, together with their nonliving, or physical environment e.
Biome—group of ecosystems that have the same climate and similar dominant communities f.
Biosphere—the highest level of organization that ecologists can study
1

g.
Diagram:
C.
D.
Biotic and Abiotic Factors a.
Biotic factors—Biological influences on organisms within an ecosystem i.
Example: Bullfrog ii.
What BIOTIC factors might influence, or affect, the bullfrog?
1.
Tiny plants and algae it eats as a tadpole
2.
Herons that eat the adult frog
3.
Other species that compete with the frog for food and space b.
Abiotic—physical, or nonliving, factors that shape ecosystems i.
Example: Temperature, humidity, precipitation, wind, soil, sunlight, water ii.
Example: Bullfrog iii.
What ABIOTIC factors might influence, or affect, the bullfrog?
1.
Availability of water
2.
Temperature of the air c.
Habitat i.
Area where an organism lives ii.
Includes biotic and abiotic factors iii.
Determines the survival and growth of an organism
The Niche a.
If the organism’s habitat is its “address”, its niche is its “occupation” b.
Niche—full range of physical and biological conditions in which an organism lives and the way in which the organism uses those condition c.
Includes the type of food the organisms eats, how it obtains this food, and which other organisms species use the organism as food
2

E.
Community Interactions a.
Competition i.
Occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time ii.
Resource—refers to any necessity of life, such as water, nutrients, light, food, or space iii.
Direct Competition in nature often results in a winner and a loser—with the losing organism failing to survive iv.
Competitive Exclusion Principle—states that no two species can occupy the same niche in the same habitat at the same time b.
Predation i.
Interaction in which one organism captures and feeds on another organism ii.
Predator —the organism that does the killing and eating Ex: Tiger iii.
Prey —food organism Ex: Mouse c.
Symbiosis i.
Any relationship in which two species live closely together ii.
Symbiosis means “living together” iii.
There are three main classes of symbiotic relationships in nature:
1.
Mutualism a.
Both species benefit from the relationship b.
Ex: Flowers and Insects i.
Flowers need Pollinators (bees, butterflies) to reproduce ii.
Pollinators obtain food from the flowers nectar iii.
Both are benefited —MUTUAL
2.
Commensalism a.
One member benefits and the other is neither helped nor harmed b.
Ex: Barnacles and Whales i.
Barnacles, small marine animals, attach themselves to Whales ii.
Barnacles perform no service to the Whale, but do not harm them either iii.
As the whale swims, the Barnacles are able to eat the food particles that pass by— one benefits, other unharmed/not benefited
3.
Parasitism a.
One organism lives on or inside another organism and harms it b.
The parasite obtains all or part of its nutritional needs from the other organism, called the host c.
Ex: tapeworms i.
Live inside the intestines of their host ii.
Absorb most of the food’s nutrients d.
Ex: Fleas, ticks, lice i.
Live on the bodies of mammals ii.
Feed on blood and skin of host
3

Objectives:
A.
Producers
1.
Sunlight is the main energy source for life on Earth
2.
In few ecosystems, some organisms obtain energy from other sources than the sun a.
inorganic compounds store energy b.
example: mineral water that flows underground or boils out of hot springs and undersea vents is loaded with chemical energy
3.
Autotrophs a.
use energy from the sunlight to make their own food b.
Example: Plants
4.
Producers—capture energy from sunlight
5.
Energy From the Sun a.
Photosynthesis—uses light energy to convert carbon dioxide and water into oxygen and sugars/starches b.
On land, plants are the main autotrophs c.
In water, algae are the main autotrophs
6.
Life Without Light a.
Chemosynthesis—using chemical energy to produce carbohydrates b.
Occurs in very remote places: volcanic vents, hot springs, tidal marshes
B.
Consumers
1.
Heterotrophs—rely on other organisms for their energy and food supply; also called “Consumers”
2.
There are many different types of heterotrophs/consumers: a.
Herbivores—eats plants Ex: horse b.
Carnivores—eats animals Ex: lion c.
Omnivores—eat both plants and animals Ex: pig d.
Detritivores—eat plant and animal remains and other dead matter, otherwise known as
“detritus” Ex: maggots e.
Decomposers—break down organic matter Ex: earthworms
4

C.
Feeding Relationships
1.
Food Chains a.
Energy stored by producers can be passed through a food chain b.
Series of steps in which organisms transfer energy by eating and being eaten c.
Show a one-way flow of energy in an ecosystem d.
Example: producer (grass)  consumer (antelope)  carnivore (coyote) e.
Diagram:
2.
Food Webs a.
Feeding relationships among various organisms in an ecosystem form a network of complex interactions b.
Links all the food chains in an ecosystem together c.
Shows MULTIPLE ways of energy in an ecosystem d.
Diagram:
3.
Trophic Levels a.
Trophic Level—each step in a food chain or food web b.
Producers make the first trophic level c.
Consumers make up the second, third, or higher trophic levels d.
Each consumer depends on the trophic level below it for energy e.
Diagram:
5

D.
Ecological Pyramids
1.
Amount of energy or matter in an ecosystem can be represented by an ecological pyramid
2.
Ecological Pyramid—diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web
3.
Ecologists have three types of pyramids: a.
Energy Pyramid i.
Only part of the energy that is stored in one trophic level is passed on to the next level ii.
Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. iii.
The more levels that exist between a producer and a top-level consumer, the less energy that remains from the original amount. b.
Biomass Pyramid i.
Biomass—the total amount of living tissue within a given trophic level ii.
Represents the amount of potential food available for each trophic level in an ecosystem iii.
Typically, the greatest biomass is at the base or bottom of the pyramid iv.
Diagram: c.
Pyramid of Numbers—shows the relative number of individual organisms at each trophic level
6

Objectives:
A.
Recycling in the Biosphere
1.
Energy is crucial to an ecosystem, but organisms need more than energy to survive
2.
More than 95% of the body is made up of just four elements: Oxygen, Carbon, Hydrogen, and
Nitrogen
3.
Unlike the one-way flow of energy, matter is recycled within and between ecosystems
4.
Biogeochemical Cycles—the passing of elements, chemical compounds, and other forms of matter from one organism to another and from one part of the biosphere to another
B.
The Water Cycle
1.
All living things require water to survive
2.
Evaporation—process in which water changes from liquid form to gas form
3.
Transpiration—water evaporating from leaves into the atmosphere
4.
Condensation—tiny droplets that form clouds
5.
Precipitation—when droplets become large enough, water returns to Earth’s surface in the form of rain, snow, sleet, or hail
6.
Diagram:
7

C.
Nutrient Cycles
1.
The Carbon Cycle a.
Carbon plays many roles and is a key ingredient of living tissue b.
Four main types of processes move carbon through its cycle: i.
Biological Processes (photosynthesis, respiration) ii.
Geochemical Processes (erosion, volcanic activity) iii.
Mixed Biogeochemical Processes(burial/decomposition of dead organism) iv.
Human Activities (mining, cutting & burning forests, burning fossil fuels) v.
Diagram:
2.
The Nitrogen Cycle a.
All organisms require nitrogen to make amino acids, which build proteins b.
Nitrogen gas makes up 78% of the Earth’s atmosphere c.
Nitrogen Fixation—some bacteria convert nitrogen gas into ammonia while others convert ammonia into nitrates and nitrites. d.
When organisms die, decomposers return nitrogen to the soil as ammonia. e.
Denitrification—other soil bacteria convert nitrates into nitrogen gas; process releases nitrogen back into the atmosphere again f.
Diagram:
8

3.
The Phosphorus Cycle a.
Phosphorus is essential because it forms part of important life-sustaining molecules such as
DNA and RNA b.
Phosphorus does not enter the atmosphere c.
Instead it remains mostly on land in rock and soil minerals, and in ocean sediments. d.
Diagram:
9

Objectives:
A.
Ecological Succession
1.
Ecosystems are constantly changing in response to natural and human disturbances a.
As an ecosystem changes, older inhabitants gradually die out and new organisms move in b.
Ecological Succession—series of predictable changes that occurs in a community over time c.
Sometimes succession results from slow changes in the physical environment d.
Sometimes succession results from sudden natural disturbances from human activity, such as clearing a forest
2.
Primary Succession a.
Primary Succession —occurs on surfaces where no soil exists b.
Occurs on the surfaces formed as volcanic eruptions build new islands or cover the land with lava rock or volcanic ash c.
Occurs on bare rock exposed when glaciers melt d.
Pioneer Species —the first species to populate the area
1.
Pioneer species on volcanic rock is typically lichens
2.
Lichen is made up of fungus and algae and can grow on bare rock
3.
As lichens grow, they help break up the rocks.
4.
When they die, lichens add organic material to help form soil in which plants can grow
3.
Secondary Succession a.
Secondary Succession —succession following a disturbance that destroys a community without destroying the soil b.
Caused by natural events, such as fires, or human activity, such as farming
4. Venn Diagram:
10

Objectives:
the relationships among organisms, populations, communities, ecosystems, and biomes
A.
B.
C.
D.
E.
Biomes and Climate
1.
Biomes—complex terrestrial communities that cover a large area and are characterized by certain soil and climate conditions and particular assemblages of plants and animals
2.
Tolerance—ability to survive and reproduce under certain conditions that differ from their optimal conditions
3.
Microclimate—climate in a small area that differs from the climate around it
Tropical Rainforest
1.
Home to more species than all other biomes combined
2.
Canopy —tops of the tall trees (extending 50-80 m above the forest floor)
3.
Understory—second layer of shorter trees and vines
4.
Abiotic factors: hot and wet year-round, thin, nutrient-poor soil
5.
Dominant plants: broad-leaved evergreen trees, ferns, large woody vines
6.
Dominant wildlife: sloths, jaguars, ant-eaters, monkeys, anacondas, toucans
Temperate Deciduous Forest
1.
Deciduous —tree that sheds its leaves
2.
Abiotic factors: generally warm year-round, alternating wet and dry seasons
3.
Dominant plants: tall, deciduous trees such as sugar, maple, birch, oak, pine, flowering plants, and moss
4.
Dominant wildlife: white-tailed deer, cottontail rabbit, squirrel, raccoon
Savannah
1.
Also called “grasslands”
2.
Abiotic factors: warm temperatures, seasonal rainfall, compact soil, and frequent fires set by lightening
3.
Dominant plants: tall, perennial grasses, shrubs
4.
Dominant wildlife: lions, leopards, cheetahs, hyenas, elephants, giraffes, antelopes, zebras, ostriches, eagles
Desert
1.
All deserts are dry—receive less than 25 cm of annual precipitation
2.
Can be hot deserts AND cold deserts!
3.
Abiotic factors: low precipitation, variable temperatures, soils rich in minerals but poor in organic material
4.
Dominant plants: cacti, creosote bush
5.
Dominant wildlife: mountain lions, bobcats, kangaroo rats, hawks, bats, rattlesnakes, lizards, tortoises, roadrunners
11

F.
G.
H.
I.
J.
K.
L.
Boreal Forest
1.
Dense evergreen forests of coniferous trees
2.
Also called the “Taiga”
3.
Winters are bitterly cold, but summers are mild and long enough to allow the ground to thaw
4.
Abiotic factors: long, cold winters, short, mild summers, moderate precipitation, high humidity, acidic, nutrient-poor soil
5.
Dominant plants: needle leaf coniferous trees such as spruce and fir, some broadleaf deciduous trees, small berry-bearing shrubs
6.
Dominant wildlife: lynxes, timber wolves, moose, beavers, songbirds, migratory birds
Tundra
1.
Permafrost—layer of permanently frozen subsoil
2.
During short, cool summers, the ground thaws to a depth of a few centimeters and becomes soggy and wet
3.
In winter, the topsoil freezes again
4.
Abiotic factors: strong winds, low precipitation, short and soggy summers, long, cold, and dark winters, poorly developed soil, permafrost
5.
Dominant plants: ground-hugging plants such as mosses, lichens, short grasses
6.
Dominant wildlife: few mammals that can withstand the harsh conditions, musk ox, Arctic foxes, caribou, lemmings and other small rodents
Aquatic Biomes
1.
Divided into freshwater and marine
2.
Freshwater includes lakes, rivers, streams, and ponds
3.
Marine includes open ocean, rocky intertidal zones, and estuaries
Freshwater
1.
Abiotic factors: seasonal fluctuations of depth and temperature
2.
Biotic factors: freshwater plants, algae, insects, fish, wading birds, phytoplankton, zooplankton
Open Ocean
1.
Abiotic factors: temperature range varies with latitude and water depth, sunlight decreases with water depth, water density changes with temperature and salt content
2.
Biotic factors: phytoplankton, fish, dolphins, whales, seals, sea birds
Rocky Intertidal
1.
Abiotic factors: alternating exposure to direct sunlight and submergence, salinity changes, rocky substrate
2.
Biotic factors: algae, sea urchins, clams, mussels, starfish
Estuaries
1.
Estuaries—Estuaries—wetlands formed where rivers meet the sea
2.
Contain a mixture of freshwater and saltwater
3.
Abiotic factors: large fluctuations in salinity, extreme temperature changes
4.
Biotic factors: algae, mosses, aquatic plants, insects, shrimp, crabs, amphibians, birds
12