Ecosystems and Energy

“eco-” = house The study of the interactions

among organisms and between organisms and their abiotic environment

Abiotic factors: sunlight, wind, living space, precipitation, temperature, soil, wind

Studies levels of biology above the individual

Populations: groups of species (members breed naturally to produce fertile offspring)

Communities: all the populations in an area

Ecosystem: the community including the abiotic factors.

Biosphere – layer of earth containing all living things. A study would include the air, water, land and organisms. Atmosphere: gaseous layer

surrounding Earth Hydrosphere: Earth’s water– frozen

and liquid Lithosphere: soil and rock of Earth’s

crust

Essential for life The capacity/ability

to do work Units: Joules (J) –

units of work - or calories (cal) – units of heat energy

Forms: chemical, radiant/solar, heat, mechanical, nuclear, and electrical

Can be stored – potential energy – or as moving energy – kinetic energy.

A plant that a meadow vole (rodent) eats contains chemical potential energy and is converted to kinetic energy and heat as the vole moves.

Study of energy and its transformations

Closed system – an object being studied that exchanges energy, but not matter with its surrounding.

Open system – an object studied that can exchange energy/matter with its surroundings.

Energy cannot be created or destroyed. It can transform from one form to another. Ex: absorb energy from the sun or give off

energy to surroundings. It changes, but wasn’t created or destroyed.

All living things need energy and can’t create it. They must get it from their environment. Plants get solar energy and convert to chemical energy in the bonds of sugar. Animals get energy (chemical) from eating plants/animals and convert energy to mechanical energy for movement.

When energy transforms, some usable energy degrades into heat, a less-usable form of energy. Usable energy for biological work

decreases through an ecosystem. Entropy: a measure of disorganized, less-

usable energy. If all energy were heat, life would cease to

exist. Entropy increases through an ecosystem.

Energy conversion is never 100% efficient, some energy is always “lost” as heat.

And automobile is about 25% efficient converting chemical energy of gas to mechanical energy

Cellular metabolism is about 50% efficient.

Producers are essential for getting energy into organisms photosynthesis and chemosynthesis (from hydrogen sulfide – H2S @ hydrothermal vents)

Biological process by which energy from the sun (radiant energy) is transformed into chemical energy of sugar molecules

6 CO6 CO2 2 + 12 H+ 12 H22O + radiant energy O + radiant energy

Energy captured by plants via photosynthesis is transferred to the organisms that eat the plants

CC66HH1212OO66 + 6 H + 6 H22O + 6 OO + 6 O22

The process where the chemical energy captured in photosynthesis is released within cells of plants and animals

This energy is then used for biological work Creating new cells, reproduction,

movement, etc.

CC66HH1212OO66 + 6 + 6 OO2 2 + 6 H+ 6 H22O O 6 CO6 CO22 + 12 H + 12 H22O + energyO + energy

Producers/autotrophs: land – mainly plants; water – algae, phytoplankton

Consumers/heterotrophs: primary, secondary, tertiary and herbivores, carnivores, omnivores, detritus feeders/detrivores

Decomposers/saprotrophs – microbial, return inorganic molecules (carbon dioxide, salts) to environment

One way; once energy has been used biologically, it becomes unusable

Follows food chain Trophic levels Food webs – realistic model

10 %

rule!!!

NOTE: ARROW DIRECTION, LOCATION OF PRODUCERS

Pictures to represent available energy

# of organisms with appropriate area according to size.

Inverted pyramids do exist: decomposers, parasites

Biomass= measure of total amount of living material

Units typically kilocalories per square meter per year

Less energy available at each successive trophic level.

10% rule

Gross primary productivity (GPP): Total amount of energy captured during

photosynthesis (for a given time period) Net primary productivity (NPP): The amount of energy left after cellular

respiration in the plant; plant growth per unit area per unit time)

NPP = GPP – plant respiration NPP is the energy available to consumers

If a forest nets 1500 g/m2/yr and uses 1000 g/m2/yr. How much energy does that forest capture annually?

4 – I feel extremely confident about any calculations regarding primary productivity

3 – I feel confident about primary productivity calculations

2 – With a bit more help I could do these calculations

1 – I really don’t get this

What abiotic factors effect

productivity?Know the

most/least productive environments and why they are/are not productive.