Biodiversity.

As the name suggest biodiversity is the diversity of the living organisms in an ecosystem, meaning the number of genetically and morphologically different species of plants, animals and other organisms in a given area. A high biodiversity indicates many different types of organisms, and a low biodiversity means fewer different species of organisms. For pragmatic reasons this usually excludes bacteria, archaea and single-celled fungus (yeast), These groups are very abundant on earth while being very difficult to identify using classical methods. However, with the introduction of easily accessible genetic methods, these organisms are now more commonly included.

Biodiversity is dependent on many abiotic factors from altitude, temperature, readily available nutrients and "harshness" of the area. Furthermore, along with abiotic factors and relationships between and within species, biodiversity is also dependent on the availability of ecological niches, for more info try the niche-simulation.

In biology and ecology, a high degree of diversity is desired as it often indicates a healthy ecosystem. Importantly, a high diversity does not guarantee a community is healthy, and a low diversity community can be as healthy; though usually, they are more prone to suffer irreparable damage from smaller perturbations. Conversely, an ecosystem with a healthy biodiversity can recover from many different disasters.

To assess the biodiversity of an area sampling is necessary, this can be done in many ways, from using quadrats to setting various types of traps suited for the types of organisms you are interested in. Some traps use lures in the form of pheromones (such as a sticky trap) or food, other traps rely on the animal's behavior and movements to trap them, such as pitfall trap and camera traps. To make the data accessible to non-experts tools such as dichotomous keys are used, today you can get smart-phone apps and web pages which will allow you to identify certain mainstream organisms such as edible fungi or birds. To quantify biodiversity a biodiversity index is useful, it compares the number of different species to the total number of specimens.

The newest method to assess the biodiversity of a given area is to use environmental DNA, where with a cup of water or a soil sample, a laboratory and a reference database can determine with high precision which organisms have been present recently.

On Earth we observe a trend in the biodiversity, it follows the altitudinal gradient of an area. With the highest biodiversity at intermediate altitudes, with a drop towards lower and higher altitudes, this trend is duplicated on the fictional planet Astakos IV.