Britannica
Sources used in this answer
- polar ecosystem - Development and structure of populations and communities
- biogeographic region - Components of species diversity: species richness and relative abundance
- tropical rainforest - Biological productivity
- Pleistocene Epoch - Migration of plants and animals
- climate change - The last deglaciation
- primary productivity
Why do tropical regions generally have more species than Arctic regions?
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ecology
Mourning doves (Zenaida macroura) on their nest protected within the prickly branches of a cactus in the Sonoran Desert, Arizona, U.S.
Tropical regions generally support higher species diversity than Arctic regions due to a combination of favorable ecological factors that create more inviting habitats.1
The primary drivers of this latitudinal gradient include:
- Climate: Tropical regions benefit from higher temperatures, greater climate predictability, and longer growing seasons, which collectively permit a wider range of species to thrive.1
- Productivity: Tropical environments, such as tropical rainforests, experience climatic conditions that are less limiting to plant growth, leading to higher net primary productivity and biomass compared to polar zones.23
- Habitat Complexity: The tropics offer a wider variety of habitats, whereas polar ecosystems are characterized by relative simplicity and lower productivity.41
In contrast, Arctic regions are defined by short growing seasons and extreme weather, which limit the rate of nutrient release through decomposition and force animal populations to live near their biological limitations. This harshness results in lower species richness and ecosystems that are less stable, often experiencing wide population fluctuations.41