The Latitudinal Diversity Gradient

The number of species differs from one ecosystem to another. Ecosystems with big biodiversity concentrations include tropical forests, tropical lakes, coral reefs, and the deep sea. Biodiversity concentration increases from the poles to the equator; this phenomenon is known as the latitudinal diversity gradient (Brown, 2014). Researchers have done various studies in an attempt to explain the latitudinal diversity gradient; there are several plausible explanations for the high biodiversity concentration in the tropics. One of the most prominent explanations for the high biodiversity in the tropics is that the tropics have higher rates of productivity than other regions due to climatic conditions. The terrestrial net primary production is mainly determined by the average temperature and how seasons change throughout the year (Cunningham & Cunningham, 2019). The poles and deserts have low productivity due to low temperatures and lack of precipitation. In contrast, the tropics receive high rainfall and there is enough solar energy throughout the year. The sun is the primary source of energy that supports life. The abundant solar energy and precipitation make biomass production per hectare higher in the tropics than in temperate regions, meaning the tropics have enough resources to sustain many species (Cunningham & Cunningham, 2019). Another explanation for the high biodiversity in the tropics is that areas near the equator have stable climatic conditions; this allows specialization and adaptation of different species to their habitats (Cunningham & Cunningham, 2019). In temperate regions, the large temperature variations from season to season, and the scouring action of glaciers interrupts the evolution and adaptation of different species (Cunningham & Cunningham, 2019). Greater competition and niche specialization among tropical species have also been fronted as explanations for the latitudinal diversity gradient. The climatic stability of the tropics means that there is high interaction among species and high parasite populations. The two factors allow many species to coexist because there are no dominant species (Brown, 2014). Finally, the tropics have a large continuous geographical area compared to the temperate regions, which are separated by the tropics. That reduces the extinction rate in the tropics. 

References  

Brown, J. H. (2014). Why are there so many species in the tropics? Journal of Biogeography , 8-22. 

Cunningham, W. P., & Cunningham, M. A. (2019). Principles of environmental science: Inquiry & application (9th ed.). New York: McGraw-Hill Education