Ecology review:

What is Ecology? (a brief review)

• Ecology-

• the study of interactions between– organisms and organisms– organisms and their environment

Where do we fit in?

(What is our environment?)

The Biosphere!

Factors that effect us:1. Abiotic Factors

Wind/Air currentsMoisture

Soil

Light

Temperature

• A- stands for non• Bio- stands for living

• Abiotic Factors- nonliving factors

2. Biotic Factors:

• Biotic- Living factors

What is the organization of Ecological Study?

Population

Community

Ecosystem

Biosphere

Organism

Levels of Organization• Individual- one

organism (living)

• Ex a moose

Levels of Organization• Population- groups

of individuals that belong to the species and live in the same area. (living-living same species)

• Ex many moose

Levels of Organization

• Community- groups of different populations (more than one population or different groups of species)

Ex many groups of moose beavers, trees, grass (all living)

Levels of Organization• Ecosystem- all

organisms in a particular area along with the nonliving. (living and nonliving)

Ex many groups of moose beavers, trees, grass, rocks, water, mountains

Levels of Organization

• Biome- group of ecosystems that have the same climate and similar dominant communities

• Biomes: tropical rain forest, tropical dry forest, tropical savannah, temperate grassland, desert, temperate woodland and shrubland, temperate forest, northwestern coniferous forest, boreal forest (taiga), tundra, mountains and ice caps

Levels of Organization• Biosphere- all of the

planet where life exhists, includes land, water, and, air

• Life extends 8 km up and 11 km below the surface

IN AN ECOSYSTEM:

Organisms live in a Habitat

Organisms fit into a Niche of the environment

Habitat vs. Niche• Habitat- an area where an organism lives • Niche- an organisms role in its environment

– The Long Version full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. Includes where in the food chain it is, where an organism feeds

• Habitat is like an address in an ecosystem and a niche is like an occupation in an ecosystem.

ENERGY FLOW

Autotrophs vs. Heterotrophs

Energy Flow (Trophic Levels)• Producers- make

their own food• Consumers- get

energy from consuming producers

Producers• Producers- capture

energy from sunlight or chemicals and use the energy to produce food.

• Producers are autotrophs- they make food from their environment

2 main types of autotrophs• One type gets energy

from the sun-by photosynthesis

• Another type gets energy without light- by chemosynthesis

Consumers• Consumers are

heterotrophs- get energy from other organisms

Types of Consumers• Herbivores- eat only plants• Carnivores- eat animals• Omnivores- eat both plants and animals• Detritivores- eat dead matter (plants and

animals)

Feeding Relationships• Energy flows through an ecosystem in one direction

from:– 1. the sun or inorganic compounds– 2. To autotrophs (producers)– 3. To heterotrophs (consumers)– Decomposers get energy from decomposing dead

organisms

Food Web- A network of feeding relationships.

(More realistic that a food chain)

Food Chain- a series of steps in which organisms transfer energy by eating or being eaten.

Food Web

They can become very complex!

Trophic levels

• Each step in a food chain or a food web is called a trophic level.– Producers are the first

trophic level– Consumers are the

second, third, or higher trophic level

• Each trophic level depends on the one below for energy

Energy Pyramid• Only part of the energy

stored in one level can be passed to the next- most energy is consumed for life processes (respiration, movement, etc., and heat is given off)

• Only 10% of the energy available within one trophic level is transferred to organisms in the next trophic level

Biomass Pyramid• Biomass- the total

amount of living tissue within a given trophic level.

• A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Energy Losses

• Energy transfers are never 100 percent

efficient

• Some energy is lost at each step

• Limits the number of trophic levels in an

ecosystem

• Energy flow is a one way path! (not a cycle)

All Heat in the End

• At each trophic level, the bulk of the energy received from the previous level is used in metabolism

• This energy is released as heat energy and lost to the ecosystem

• Eventually, all energy is released as heat

• All living organisms need certain elements/compounds for life processes– Ex: your cells need C,H,O,P,N & S in order to

live and reproduce (make more cell)

• Cycles in nature keep these elements “moving” from organisms to organism (and sometimes into the atmosphere)

Biogeochemical Cycles(Matter moving through the environment)

Biogeochemical Cycles(Matter moving through the environment)

• The flow of a nutrient from the environment to living

organisms and back to the environment

• Main reservoir for the nutrient is in the environment

• Transfer rates to and from reservoir are usually lower

than the rates of exchange between and among

organisms.

• Matter is recycled through an ecosystem – not one way

flow

Three Categories

• Hydrologic cycle

– Water

• Atmospheric cycles

– Nitrogen and carbon

• Sedimentary cycles

– Phosphorus and sulfur

CYCLES IN NATURE

Carbon Cycle

• Carbon moves through the atmosphere

and food webs on its way to and from

the ocean, sediments, and rocks

• Sediments and rocks are the main

reservoir

Carbon Cycle

photosynthesisTERRESTRIAL

ROCKS

volcanic action

weathering

diffusion

Bicarbonate, carbonate

Marine food webs

Marine Sediments

Atmosphere

TerrestrialRocks

Soil WaterPeat, Fossil

Fuels

Land Food Webs

Carbon in Atmosphere

• Atmospheric carbon is mainly carbon dioxide

• Carbon dioxide is added to atmosphere– Aerobic respiration, volcanic action,

burning fossil fuels, decomposition of organic materials

• Removed by photosynthesis

Nitrogen Cycle• Nitrogen is used in amino acids and nucleic acids

(all living organism need nitrogen to make

proteins)

• Main reservoir is nitrogen gas in the atmosphere

• Decomposers are vital to convert ammonia into:

1. usable nitrites & nitrates for plants (nitrogen fixation)

2. nitrogen gas (denitrification = puts it back into the atmosphere)

Phosphorus Cycle• Phosphorus is part of phospholipids and all

nucleotides

– What are these?

• It is the most prevalent limiting factor in

ecosystems

• Main reservoir is Earth’s crust; no gaseous

phase (it never enters the atmosphere – like

carbon and nitrogen)

Phosphorus Cycle

GUANO

FERTILIZER

ROCKS

LAND FOOD WEBS

DISSOLVED IN OCEAN

WATER

MARINE FOOD WEBS

MARINE SEDIMENTS

excretion

weathering

mining

agriculture

uptake by autotrophs

death, decomposition

sedimentation setting out leaching, runoff

weathering

uplifting over geolgic time

DISSOLVED IN SOILWATER,

LAKES, RIVERS

uptake by autotrophs

death, decomposition