47-4 Energy and Nutrients

Building the Web of Life

The Flow of Energy

Energy flows through an ecosystem from the sun to producer and then to consumers.

Producer –Photosynthetic organisms like plants and certain bacteria are able to make there own food from inorganic substances. Primary consumer – herbivores (plant eating animals)Secondary consumer – feed on primary consumersTertiary consumer – feeds on secondary consumer*Decomposers – fungi and bacteria feed on non-living organic matter.

Ecological Pyramids

Ecologist use ecological pyramids to represent the energy relationships among trophic (feeding) levels.

Three types of pyramids:1. Pyramid of Energy: shows the total amount of incoming energy (heat) at each trophic level. Total energy decreases at each successive level.2. Pyramid of Biomass: shows the total mass of living tissues at each level. Example: a large amount of grass is needed to feed a single rabbit.3. Pyramid of Numbers: shows the total number of organisms at each level. Usually decreases at each successive level.

Where does the energy come from?

Producers use the sunlight to make their energy through a process called photosynthesis.

The reaction is as follows:

6CO2 + 6H2O C6H1206 + 602

This reaction occurs in a chloroplast of a plant cell. The pigment chlorophyll absorbs the sunlight and through various reactions produce sugar (food).

How do organisms use the energy?

Most organisms have an organelle called mitochondria. This organelle carries out a series of reactions that eventually produces energy.

This reaction is called cellular respiration and it uses oxygen to break down food molecules to produce energy.  The reaction is as follows: 

C6H1206 + 602 energy + 6CO2 + 6H2O Animals and plants are connected to one another in a network of feeding relationships.

Nutrient Limitation

The rate at which producers can capture energy and use it to produce living tissue is controlled by several factors; one of which is the amount of available nutrients.

If a nutrient is in short supply, it can limit an organism’s growth becoming a limiting factor.

Biogeochemical Cycles

Nutrients move through the biosphere in a series of physical and biological processes.

They are called cycles because nutrients, unlike energy, may be used over and over again by living systems.

Carbon Oxygen Cycle

Feeding Relationships

Food Chain: (simplest) series of organisms through which food is passed in an ecosystem.

Food Web: complex relationships formed by interconnected and overlapping food chains.

*remember arrows indicate the direction of

the energy.

Feeding Relationships

BiomesLand

BiomeLocation Plants Animals Climate

Tundra   

•  List where on the planet this biome can be found

• List some indicator species for each biome

 

•  List some of the major

primary, secondary

and consumers as well as

apex predators

•  List the temperature range, typical

seasons and

precipitation for each

biome

Taiga   

TemperateDeciduous

Forest 

Grassland  

Tropical Rain

Forest  

Desert 

Water Biome

Location Plants Animals Climate

Fresh Water

   

  

Same  

  

 for

  

 aquatic

  

 biomes!Marine  

Estuary