Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (N2O) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of N2O emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems.
Read more about Human Impact On The Nitrogen Cycle: History of Anthropogenic Nitrogen Inputs, Impacts of Anthropogenic Inputs On The Nitrogen Cycle, Integration
Famous quotes containing the words human, impact and/or cycle:
“There’s nothing that makes you so aware of the improvisation of human existence as a song unfinished. Or an old address book.”
—Carson McCullers (1917–1967)
“If the federal government had been around when the Creator was putting His hand to this state, Indiana wouldn’t be here. It’d still be waiting for an environmental impact statement.”
—Ronald Reagan (b. 1911)
“The cycle of the machine is now coming to an end. Man has learned much in the hard discipline and the shrewd, unflinching grasp of practical possibilities that the machine has provided in the last three centuries: but we can no more continue to live in the world of the machine than we could live successfully on the barren surface of the moon.”
—Lewis Mumford (1895–1990)