Cultural eutrophication activity. Polar regions have less human activity and subsequently less cultural eutrophication. One response to added amounts of nutrients in the aquatic ecosystem is the rapid growth of microscopic algae, also known as an algal bloom. In freshwater systems, the formation of floating algal blooms are commonly nitrogen-fixing cyanobacteria (blue-green algae). This outcome is favoured when nitrogen inputs are reduced and phosphorus inputs are increased. Large amounts of algae reduce the amount of dissolved oxygen available in the water for other organisms, which increases fish mortality rates. These areas affected by algal blooms are known as dead zones, and are
Plant to plant communication via mycorrhizal networks can transfer various infochemicals is that they have been show to transfer molecules such as lipids, carbohydrates and amino acids. Thus, transfer of infochemicals via mycorrhizal networks can act to influence plant behavior. There are three main types of infochemicals shown to act as response inducing signals or cues by plants in mycorrhizal networks, as evidenced by increased effects on plant behavior: allelochemicals, defensive chemicals and nutrients. Allelopathy is the process by which plants produce secondary metabolites known as allelochemicals, which can interfere with the development of other plants or organisms. Allelochemicals can affect nutrient uptake, photosynthesis and growth; furthermore,