The Nutrient Cycle

Objectives Compare environmental variations and adaptations of organisms in different ecosystems

From the Video Homework What were the 3 positive interactions with the bacteria? How were they interaction?

Human Impacts on the Environment Questions to Think about as you are watching the video … How are human interaction interrupting the different ecosystems and the cycles? Why do we, humans, need the ecosystem and other organisms?

MATERIAL CYCLES In a self-sustaining ecosystem, materials must be cycled among the organisms and the abiotic environment. Thus the same materials can be reused. Materials constantly need to be recycled from the living and non-living environment so that materials can be reused by different living organisms.

The Water Cycle Water enters the atmosphere as water vapor, a gas, when water evaporates from the ocean or other bodies of water. C. Evaporation—the process by which water changes from a liquid to a gas. A. Condensation – a process in which the gas cools and becomes a liquid

The Water Cycle B. Precipitation--rain, snow, sleet, or hail a. The sun heats the atmosphere. b. Warm, moist air rises and cools. c. Eventually, the water vapor condenses into tiny droplets that form clouds. d. When the droplets become large enough, the water return to Earth’s surface.

The Water Cycle D. Water can also enter the atmosphere by evaporating from the leaves of plants— Transpiration.

E. Surface Run-off—Precipitation runs along the surface of the ground until it enters a river or a stream that carries the run-off back to an ocean or lake. F. Seepage/ infiltration to ground water —Rain also seeps into the soil, some of it deeply enough to become ground water. Water in the soil enters plants through the roots, and the water cycle begins anew. G. Surface Water – the ocean

Condensation precipitation evaporation Transpiration Surface runoff Surface water Seepage/ infiltration

Carbon-Oxygen Cycle involves the processes of respiration and photosynthesis. In respiration, oxygen and glucose are combined releasing energy and producing water and carbon dioxide. In photosynthesis water and carbon dioxide along with the energy from the sun are combined to produce glucose (containing energy) and oxygen.

The Carbon Cycle Every organic molecule contains the element carbon. A. Carbon dioxide is taken in by plants during photosynthesis and D. given off by plants and animals during cellular respiration.

The Carbon Cycle Decomposition of dead organisms and their conversion under pressure into coal and petroleum (fossil fuels), store carbon underground. D. Decomposition take up and release carbon and oxygen into the atmosphere. Human activities, such as mining, cutting and burning forests, and E. Combustion (burning fossil fuels) release carbon dioxide into the atmosphere.

Photosynthesis Atmosphere CO2 Decomposition Combustion Cellular Respiration

The Nitrogen Cycle All organisms require nitrogen to make amino acids, which in turn are used to build proteins. Nitrogen gas makes up 78% of Earth’s atmosphere. Nitrogen containing substances such as ammonia (NH3), nitrites (NO2-), and nitrates (NO3-) are found in the wastes produced by many organisms and in dead and decaying organic matter. Nitrate is major component of plant fertilizers.

The Nitrogen Cycle 2. Nitrogen gas is the most abundant form but only certain bacteria can use this form. A. Such bacteria live in the soil and on the roots of plants. B. These bacteria convert nitrogen gas into ammonium--nitrogen fixation. C. Other bacteria in the soil convert ammonia into nitrites and nitrates.

3. Once the nitrites and nitrates are available, producers (plants) can use them to make proteins. Consumers then eat the producers and reuse the nitrogen to make their own proteins. 4. When organisms die, decomposers return nitrogen to the soil as ammonia. 5. Other soil bacteria convert nitrates into nitrogen gas--denitrification. This process releases nitrogen into the atmosphere once again.

Succession: replacement of populations in habitat as it moves toward a stable state (determined by changes in plants)

The environment may be altered in substantial ways through the activities of organisms, including humans, or when the climate changes. Although these alterations are sometimes abrupt (ex. Natural disasters), in most cases species replace others, resulting in long-term gradual changes in ecosystems.

Ecosystems tend to change with time until a stable system is formed. The type of ecosystem that is formed depends on the climatic limitations of a given geographical area.

Pioneer Organisms: The first organisms to inhabit a given location (ex. lichens on bare rock) Pioneer organisms modify their environment, thus establishing conditions under which more advanced organisms can live. (ex. seasonal dieback and erosion, for example, would create pockets of "soil" in the crevices and hollows of the bare rock inhabited by the lichen)

** Each community modifies its environment, often making it more difficult for itself and, apparently, more favorable for the following community which infiltrates the first community over a period of years.

Primary Succession: the development of plant communities on newly formed habitats that previously lacked plants (ex. a lava flow)

Secondary Succession: return of an area to its natural vegetation following a disruption or removal of the original climax community

An example of a PRIMARY SUCCESSION ex. (Adirondack Bog Succession) 1. water plants at pond edge 2. sedges and sediments begin to fill pond 3. sphagnum moss and bog shrubs fill pond (Labrador tea & cranberries) 4. black spruce and larch 5. birches, maple, or fir

An example of a SECONDARY SUCCESSION 1. plowed field 2. annual grasses 3. shrubs and briers 4. cherries, alders, and birches

Do you remember the…