Every living thing needs nutrients. Much previous work has shown that a variety of soil nutrients – in particular Nitrogen (N), Phosphorous (P), and Potassium (K) – greatly impact plant communities. Often, human behaviors, especially agricultural practices like fertilization, have generated significant shifts in these nutrients. When environments become flushed with these nutrients, overall biomass typically increases but biodiversity often decreases. This is expected according to two hypotheses:

  1. Nutrient Limitation Hypothesis: Limitations in nutrients suppress abundance, and therefore increases in nutrients will drive increased abundance.
  2. Community Homogenization Hypothesis: Species that are most efficient at utilizing resources are prevented from completely excluding other species due to resource limitations. Therefore, increases in nutrients will allow these species to competitively exclude other species, decreasing overall diversity.