mutualism

Ecosystems can be categorised into two broad categories: natural and artificial. Natural Ecosystems are those ecosystems that operate by themselves under natural conditions. These ecosystems are further categorized as Terrestrial and Aquatic Ecosystems. Terrestrial ecosystems relate to lands, whereas Aquatic ecosystems relate to fresh or marine water. Freshwater ecosystems may be Lotic or Lentic. Lotic are running water ecosystems like springs, streams or rivers, whereas Lentic Fresh Water Ecosystems may be found in standing waters of lakes, ponds, pools, puddles, ditches, swamps, etc. Marine Ecosystems are found in marine waters of salt lakes, seas, oceans and estuaries. Artificial Ecosystems are man-engineered ecosystems like crop fields, artificial ponds and lakes, aquaria, fish ponds, and abandoned mines reclaimed as lakes or water bodies for recreation.