A worm with a long, cylindrical, unsegmented body.
Central and South America.
The transfer of nitrogenous compounds from the atmosphere to the earth's surface. It can be either beneficial or detrimental to plant and animal life, depending upon the amount transferred.
The bacterial enzyme responsible for converting atmospheric nitrogen (N2), which is unavailable for plant utilization, into ammonium (NH4+), which is a nitrogenous compound readily utilized by plants.
Although it may be defined in a number of ways, it is basically the amount of organic matter produced by a plant divided by the amount of nitrogen used by the plant in producing it.
Some of the first photosynthetic products that are often transported to sinks or areas of active growth where energy is required. Some commonly studied nonstructural carbohydrates are fructose, glucose, sucrose and starch.
North Atlantic Deep Water (NADW)
Cold and salty water from the North Atlantic that, because of its greater density, sinks to the bottom of the sea and drives a great underwater "conveyor belt" current around the world's oceans that ultimately returns via the surface current of the Gulf Stream.
North Atlantic Oscillation (NAO)
Denotes the dominant mode of climate variability (particularly in winter) in the North Atlantic region extending from central North America to Europe and Northern Asia. It is described as a large-scale "seesaw" in atmospheric mass between the subtropical high and the polar low. The corresponding index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting several years.