This report presents an overview of how humans have altered the global nitrogen cycle. An introduction to the nitrogen cycle is provided; as well as human induced nitrogen fixation and its impact on the atmosphere, carbon cycle, aquatic and terrestrial ecosystem function, and biodiversity. The importance of nitrogen as a primary building block of life and its role in biological processes is also...
With this TIEE Data Set, students assess effects of phosphorus addition on algae, moss, mayflies, and arctic grayling fish in the Kuparuk River, in the foothills of the North Slope of Alaska. Data were taken over 15 years at the Arctic Long Term Ecological Research (ARC LTER) site at the Toolik field station. Phosphorus was added to the river as an experiment to study the effects of nutrient...
This report addresses pollution of aquatic ecosystems that originate from multiple unidentified sources or non point sources. Non point sources of phosphorus and nitrogen are of concern as they cause eutrophication or excessive enrichment of surface waters. Effects and remediation strategies are discussed. Non point sources, such as agricultural, urban and atmospheric ones are discussed. ...
This report addresses coastal ecosystem degradation as a consequence of human driven increases in nutrients such as Nitrogen and Phosphorus. Effects on ecological communities such as algal blooms, loss of seagrass beds, and coral leaching are described. Excess nitrogen is emphasized as being the limiting nutrient in coastal systems. Political and scientific consideration to support the control...
This report illustrates the disruption of the global water cycle as a result of human activities. The global hydrological cycle’s surface and ground water processes are detailed. The global distribution of freshwater resources and its accessibility to human populations is discussed. The increasing human demand for fresh water sources is addressed, while explaining the differences betwee...