Eutrophication and development, pollution from septic systems and sewers, sewage sludge spreading, and other human-related activities increase the flow of both inorganic nutrients and organic substances into ecosystems. Elevated levels of atmospheric compounds of nitrogen can increase nitrogen availability. Phosphorus is often regarded as the main culprit in cases of eutrophication in lakes subjected to "point source" pollution from sewage pipes. The concentration of algae and the trophic state of lakes correspond well to phosphorus levels in water. Studies conducted in the Experimental Lakes Area in Ontario have shown a relationship between the addition of phosphorus and the rate of eutrophication.
Plant to plant communication via mycorrhizal networks be related; therefore, kin selection might improve inclusive fitness and explain why a plant might support a fungus that helps other plants to acquire nutrients. Receipt of defensive signals or cues from an infested plant would be adaptive, as the receiving plant would be able to prime its own defenses in advance of an attack by herbivores. Allelopathic chemicals transferred via CMNs could also affect which plants are selected for survival by limiting the growth of competitors through a reduction of their access to nutrients and light. Therefore, transfer of the different classes of infochemicals might prove adaptive for plants.