2The Nitrogen CycleAll organisms require nitrogen to make amino acids, which are used to build proteins and nucleic acids, which combine to form DNA and RNA.
3Nitrogen gas (N2) makes up 78 percent of Earth’s atmosphere The Nitrogen CycleNitrogen gas (N2) makes up 78 percent of Earth’s atmosphere
4The Nitrogen CycleNitrogen-containing substances such as ammonia (NH3), nitrate ions (NO3), and nitrite ions (NO2) are found in soil, in the wastes produced by many organisms, and in dead and decaying organic matter.
5The Nitrogen CycleDissolved nitrogen exists in several forms in the ocean and other large water bodies.
6The Nitrogen CycleAlthough nitrogen gas is the most abundant form of nitrogen on Earth, only certain types of bacteria that live in the soil and on the roots of legumes can use this form directly.The bacteria convert nitrogen gas into ammonia, in a process known as nitrogen fixation.
7The Nitrogen CycleOther soil bacteria convert fixed nitrogen into nitrates and nitrites that primary producers can use to make proteins and nucleic acids.
8The Nitrogen CycleConsumers eat the producers and reuse nitrogen to make their own nitrogen-containing compounds
9The Nitrogen CycleDecomposers release nitrogen from waste and dead organisms as ammonia, nitrates, and nitrites that producers may take up again
10The Nitrogen CycleOther soil bacteria obtain energy by converting nitrates into nitrogen gas, which is released into the atmosphere in a process called denitrification
11The Nitrogen CycleA small amount of nitrogen gas is converted to usable forms by lightning in a process called atmospheric nitrogen fixation
12The Nitrogen CycleHumans add nitrogen to the biosphere through the manufacture and use of fertilizers. Excess fertilizer is often carried into surface water or groundwater by precipitation
15Phosphorus forms a part of vital molecules such as DNA and RNA. The Phosphorus CyclePhosphorus forms a part of vital molecules such as DNA and RNA.Although phosphorus is of great biological importance, it is not abundant in the biosphere.
16The Phosphorus CyclePhosphorus in the form of inorganic phosphate remains mostly on land, in the form of phosphate rock and soil minerals, and in the ocean, as dissolved phosphate and phosphate sediments.
17The Phosphorus CycleAs rocks and sediments wear down, phosphate is releasedSome phosphate stays on land and cycles between organisms and soil
18The Phosphorus CyclePlants bind phosphate into organic compounds when they absorb it from soil or water
19The Phosphorus CycleOrganic phosphate moves through the food web, from producers to consumers, and to the rest of the ecosystem
20The Phosphorus CycleOther phosphate washes into rivers and streams, where it dissolves. This phosphate eventually makes its way to the ocean, where marine organisms process and incorporate it into biological compounds
24Nutrient Limitation in Soil All nutrient cycles work together like the gears shown.If any nutrient is in short supply—if any wheel “sticks”—the whole system slows down or stops altogether.
25Nutrient Limitation in Aquatic Ecosystems Oceans are nutrient-poor compared to many land areas.In the ocean and other saltwater environments, nitrogen is often the limiting nutrient.In streams, lakes, and freshwater environments, phosphorus is typically the limiting nutrient.
26Nutrient Limitation in Aquatic Ecosystems Sometimes an aquatic ecosystem receives a large input of a limiting nutrient—for example, runoff from heavily fertilized fields
27Nutrient Limitation in Aquatic Ecosystems The result of this runoff can be an algal bloom—a dramatic increase in the amount of algae and other primary producers due to the increase in nutrientsIf there are not enough consumers to eat the algae, an algal bloom can cover the water’s surface and disrupt the functioning of an ecosystem.
28EutrophicationA “bloom" or great increase of phytoplankton in a water body as a response to increased levels of nutrients.Hypoxia- the depletion of oxygen in the waterCauses a reductions in specific fish and other animalsSome species (such as Nomura's jellyfish in Japanese waters) may experience an increase in population
32IRL: Deaths from Algae 2013 47,000 acres of sea grass beds 274 manatees300 pelicans62 bottle nosed dolphinsEmaciated to the point of skin and bonesAll found dead in America’s most biologically diverse estuary: the Indian River Lagoon
33Algal Blooms in IRL Floridaocean.org www.wptv.com Savethemantee.org News.wfsu.orgtcpalm.com