Cycles in Nature Ecosystems Ecosystems change over time and depend on the cycling of matter. Matter Matter on Earth is limited; therefore, it is used over and over. Each type of matter has its own cycle.

Nutrient Cycles Cycling maintains homeostasis (balance) in the environment. 3 cycles to investigate: 1. Water cycle 2. Carbon cycle 3. Nitrogen cycle

Water cycle- Evaporation, transpiration, condensation, precipitation

Water cycle-

Carbon cycle- Photosynthesis and respiration cycle carbon and oxygen through the environment.

Carbon cycle-

Photosynthesis & Respiration Photosynthesis – Plants absorb Carbon Dioxide from the air to make sugars. Humans and animals consume plants, thus acquire the carbon found within the plants. Respiration – uses oxygen to breakdown the sugar molecules, thus releasing Carbon Dioxide and H2O

Decomposition and Combustion When Bacteria and Fungi decompose organic matter – Carbon Dioxide and H2O are released into the environment. Combustion – the burning of matter such as wood or fossil fuels.

Nitrogen Cycle N is important to living things – influences Protein production and making cells for DNA The movement of Nitrogen between the Environment and Living Things is called the Nitrogen Cycle.

Nitrogen cycle- Atmospheric nitrogen (N 2 ) makes up nearly 78%-80% of air. Humans and Animals cannot use it in a gas form (that is why plants are important). Without bacteria Nitrogen could not enter living things or be returned Be ed to the Atmosphere.

Nitrogen cycle- Only in certain bacteria and industrial technologies can fix nitrogen. Nitrogen fixation-convert atmospheric nitrogen (N 2 ) into ammonium (NH 4 + ) which can be used to make organic compounds like amino acids. N 2 NH 4 +

Nitrogen cycle- Nitrogen-fixing bacteria: Some live in symbiotic relationships with plants of the legume family (e.g., soybeans, clover, peanuts).

Nitrogen cycle- Some nitrogen-fixing bacteria live free in the soil. Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies.

Regrowth Each year millions of acres of land are subjected to heavy lightning and fire. Succession – regrowth over a period of time. Primary Succession – Over long periods of time where nothing had lived before. Soil is created.

Primary Succession

Pioneer Species – a species that colonizes an uninhabited area and starts the process known as Succession. Creates Soil.

Secondary Succession Secondary Succession – occurs where communities have already existed – such a former farm. May have been destroyed by Natural disasters: floods or Fires

Mount Saint Helens 1979

Mount Saint Helens 1980

Sept 2000

Mature Communities They typical have a diverse selection of plants. Mature Communities simply have a wide variety of plants living in the same area – not just a Forest.

Biodiverse Communities Insects usually attack only one species population at any given time. Diversity provides a chance for many Plants to survive.

Toxins in food chains- While energy decreases as it moves up the food chain, toxins increase in potency. This is called biological magnification Ex: DDT & Bald Eagles DDT made their egg shell very thin – Breaking Easily.

Summary 1 Precipitation, evaporation, transpiration, and condensation are parts of the Water Cycle

Summary 1 Photosynthesis, respiration, decomposition, and combustion are parts of the Carbon Cycle.

Summary 1 In the Nitrogen Cycle – Nitrogen gas is converted into other forms and back again to gas

Summary 1 Matter is limited and changes from Environment to Living things and back again.

Summary 2 Ecological Succession is the gradual development of communities over time. Often a series of stages is observed during succession.

Summary 2 Primary Succession occurs in an area that was not previously inhabited by living things, no soil is present. Succession

Summary 2 Secondary Succession takes place in an area where an earlier community was disturbed by Natural Disasters such as landslides, floods, or plowing of the crops and where soil is present.