Using sediment gathered from the ocean floor in different areas of the world, the researchers were able to confirm that as the ice sheets started melting and the climate warmed up at the end of the last ice age, 18,000 years ago, the marine nitrogen cycle
started to accelerate.
chemical, bacterial) The processes that occur in 34 34 15 the nitrogen cycle
and the specific contributions of microbes in these processes Connections between farming 28 33 18 practices and soil/water quality Challenges faced by farmers 24 33 14 (e.
These changes are consistent with the scope of human impacts on the carbon and nitrogen cycles
Indeed, it has been predicted that humans will double the turnover rates of the terrestrial nitrogen cycle
Textbook diagrams of the nitrogen cycle
now show only microbes performing that task, Hipkin and his colleagues say in the July 1 Nature.
Human modification of the global carbon cycle (through the burning of fossil fuels) has garnered the lion's share of public attention due to the implications of climate change, yet human changes to the global nitrogen cycle
have been just as profound.
The potentially toxic chemicals of the nitrogen cycle
, ammonia, nitrate, and nitrite, were also analyzed.
And increasingly, the nitrogen cycle
is being reshaped by human activity--a process that could eventually affect virtually every ecosystem on earth.
The nitrogen cycle
is important as a limiting factor for primary production in many systems (Vitousek & Howarth, 1991).
The bay's nitrogen cycle
is almost entirely balanced by this process.
Entitled Science - The Spectrum Of Life, it deals with a series of key issues in GCSE science including the eco-system, the food chain, conservation of energy and the nitrogen cycle
Also highly recommended are these additional titles by author Diane Dakers from the Earth's Cycles in Action series: "Earth's Water Cycle (9780778706175)," "The Carbon Cycle (9780778706724)," and "The Nitrogen Cycle