Biology 20

Energy cycle

Needs for energy Producers Consumers Decomposers Convert that sunlight energy into sugars and oxygen Consumers Different levels depending on what they eat Primary, secondary, tertiary Decomposers

Matter and Energy Matter cycles and Energy flows in the biosphere

Trophic Levels

Food Chains and Webs Food chain is a linear pathways through which food is transferred to higher trophic levels. Food web is an ecosystem which shows the connection between food chains

Energy transfer Only about 10 % of energy is transferred between trophic levels. There are lots of losses of energy at each level due to the organisms of that level

Ecological Pyramids Pyramid of Number Pyramid of Biomass Represent the relative numbers of organisms at each trophic level Pyramid of Biomass Represent the relative mass of organisms at each trophic level Pyramid of Energy Represent the energy transfer of organisms at each trophic level

Water Cycle

Water Universal Solvent High boiling point Special adhesive and cohesive properties High heat capacity

Water in the Ecosystem Water is everywhere in the ecosystem 50 % of all plants and animals are comprised of water Drought can occur and affect the plants growth If a plant doesn’t get enough water the stomata close up to reduce transpiration, which will reduce the photosynthesis process

Summary There is a limited amount of water in the ecosystem Water can dissolve many different substances Water is an essential part of the ecosystem, drought and water quality

Biogeochemical Cycles Movement of nutrients within the ecosystem Some organisms store these nutrients (resrvoir) Carbon dioxide, oxgyen, sulfur, nitrogen Rapid cycling – movement between quickly

Nutrient reservoirs

Carbon Dioxide and Oxygen

Sulfur Cycle Proteins and vitamins require sulfur Plants and algae incorporate sulfur in the form (SO4-) Bacteria are an important role in the sulfur cycle to convert the sulfur. Sulfur reducers – sulfate to sulfide Sulfur oxidizers – sulfide to sulfur and sulfate

Sulfur Cycle

Acid deposition In the burning of fossil fuels, SO2 (sulflur dioxide) is released This reacts from water vapour and oxygen to form H2SO3 (sulfurous acid) and H2SO4 (sulfuric acid) both which cause acid depositions Acid rain, snow, sleet bring these back to earth and can damage plants, damage lakes and soils.

Nitrogen Cycle Nitrogen gas (N2) about 78 % of the atmosphere Essential part of proteins and genetics material (DNA) found in cells Nitrogen fixation – converting nitrogen gas to ammonium Ammonification – decomposers breaking down organic matter into ammonium Denitrification – converting nitrite or nitrate back into nitrogen gas

Nitrogen Cycle

Phosphorus Cycle An essential nutrient but limited quantities in the environment Part of DNA and ATP and component to bones and teeth Not in the atmosphere, only in the soil and water Aquatic growth is limited by amount of Phosphorus in the ecosystem

Phosphorus Cycle

Algae growth With an abundant amount of Phosphorus algae can growth rapidly. This can affect the water ecosystem.