Matter and Energy in Organisms and Ecosystems

Ecosystem Final Project

ECOLOGYThe study of interactions among organisms and between organisms and their environment, or surroundings

LEVELS OF ORGANIZATIONSpecies Populations Communities Ecosystem Biome

SPECIESA group of organisms so similar to one another that they can breed and produce fertile offspring

POPULATIONSGroups of individuals that belong to the same species and live in the same area

One Hungry Planet

NICHES

THE JOB OR ROLE OF THE ORGANISM• the type of food an organism eats•the organism’s type of shelter• the predators that eat it•the time of day it is active

ECOSYSTEM

A collection of all the organisms that live in a particular place, together with their non-living, or physical environment.

Food Webs and Trophic Levels

Energy Transfer in Food WebsAbout 10 percent of net energy production at one trophic level is passed on to the next level. Processes that reduce the energy transferred:

• Respiration• Growth and reproduction• Defecation• Non-predatory death • Nutritional quality

Producers plants and other organisms capable of carrying out photosynthesis.

Decomposersorganisms that convert dead matter into gases such as carbon and nitrogen to be released back into the air, soil or water

primarily bacteria and fungi necessary for recycling nutrients to be used again by producers

Consumersorganisms that eat something else

Primary Consumers: eat producers Herbivores

Secondary Consumers: eat primary consumersOmnivores and Carnivores

Tertiary Consumers: eat secondary consumers

ENTROPYEnergy is “lost” of becomes “disorganized” as it is transferred to heat.

FOOD WEBdiagram which completely illustrates the transfer of chemical energy within and ecosystem

ECOLOGICAL MODELS

Ecosystem models typically simplify the systems they are studying to a limited number of components that are well understood, and deemed relevant to the problem that the model is intended to solve.

MARK & RECAPTURE

A sample of the population is taken, the animals are marked, released, and a second sample is taken. After their initial release a proportion of the population will be marked. The proportion of marked animals in the second sample should reflect the proportion of animals marked in the entire population. For example, suppose that 10 animals were marked and released in the first sample. If 50% of the animals in the second sample are marked, then you can assume that 50% of the animals in the population are marked. The 10 animals in the first sample therefore represent approximately 50% of the population, so the population = 20. 

PLOTTING

You could count every individual organism in an ecosystem, but you could imagine how long this would take for small plants in a large area - just imagine trying to count all of the individual blades of grass in a football field! When conducting ecology research, scientists often select several smaller sample plots inside a larger study area. The scientists thoroughly study the smaller areas, and use information from these plots to make generalizations about the larger study area.

PLANTS AND PEOPLE

Carrying Capacity – Maximum population size an environment can sustain.

Population Density = People per km2

Human population density vs global vegetation patterns

TYPES OF POPULATION CURVES

LINEAR CURVEIncreasing the same amount at regular intervals

EXPONENTIAL CURVEThe number of intervals added to the population gets larger during each time interval

S CURVE

When a species is introduced there is rapid growth due to ample resources and few predators. Eventually the growth levels off when the population reaches the carrying capacity.

S- Curve• When a species is

introduced there is rapid growth due to ample resources and few predators

• Eventually the growth levels off when the population reaches the carrying capacity

Types of population curves