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:
“Every epoch which seeks renewal first projects its ideal into a human form. In order to comprehend its own essence tangibly, the spirit of the time chooses a human being as its prototype and raising this single individual, often one upon whom it has chanced to come, far beyond his measure, the spirit enthuses itself for its own enthusiasm.”
—Stefan Zweig (18811942)
“The question confronting the Church today is not any longer whether the man in the street can grasp a religious message, but how to employ the communications media so as to let him have the full impact of the Gospel message.”
—Pope John Paul II (b. 1920)
“Oh, life is a glorious cycle of song,
A medley of extemporanea;
And love is a thing that can never go wrong;
And I am Marie of Roumania.”
—Dorothy Parker (1893–1967)