Difference Between Biodiversity and Species Richness

Biodiversity vs Species Richness

Biodiversity and species richness are two different terms that are used in ecology yet those sound similar in meaning. In fact, the two terms are similar in one direction, but biodiversity means a lot more than just the number of species. The instances that these two terms could be used are different, and there are many other distinctions between each other. Therefore, the proper idea should be understood well about both biodiversity and species richness.


Biodiversity has been defined as the degree of variation of life forms at different levels such as species, ecosystem, biome, or the entire planet. The number of species high in a certain place means that there is a high level of biodiversity. That means the number of species corresponds with the biodiversity of a certain place or an ecosystem. However, the variations within a particular species could also be considered as the index of biodiversity, and which means the number of subspecies or the individual variations account for the biodiversity. When a large region viz. country or an island is considered, the number of different ecosystems is a great index of biodiversity of that particular region. It does not relate with the area of the considered land, but the number of ecosystems or the number of species matter for the biodiversity. As an example, Greenland is a large island but its biodiversity is much low compared to Sri Lanka where the country is a tiny island. That example gives another important meaning of the term biodiversity; that it is higher in tropical places compared to temperate regions. That is because most of the solar energy is trapped at the tropics by the green plants via photosynthesis, and there are organisms to consume that as food. Rainforests and coral reefs are amongst the ecosystems with the greatest biodiversity. According to the most accurate estimations, only 1% of the total evolved species on Earth are living in the present-day, and rest 99% belong to the extinct species due to mass extinctions.

Species Richness

Species richness is defined as the number of different species present in a certain place of interest. Since the species richness indicates a number, the value could be similar in two places where the environmental conditions are similar. However, it does not account for the importance of charismatic or endemic species. Species richness only indicates the fact of how many are there but not the fact of what is there. Therefore, the application of species richness in conservation of biodiversity is not a key component. The variation of the density of certain species is not considered in species richness. One feature of the species richness is that it treats all the species in equal respect, and it implies that all the species are common and widespread. Taxonomic diversity is the basic measurement that provides from the species richness, and the ecological mean is much less.


What is the difference between Biodiversity and Species Richness ?

• Biodiversity covers a broader field than species richness does.

• Importance of certain species in terms of taxonomical, ecological, and economical values are accounted in biodiversity, but species richness only accounts for the taxonomical diversity.

• Biodiversity applies to all the biological variations from genetic levels through species, ecosystems, and the entire planet whereas species richness is only interested in the number of species only.

• Species richness is interested in the fact that how many species are there whereas biodiversity accounts for who, what, when, how, and how many biological forms are there.