If there are no reptiles in a tundra region, it's for a reason. Reptiles are cold-blooded species, meaning their own body temperature is dependent on the temperature of their surroundings. They can only survive in warm regions―even in hot deserts. However, in cold regions, like the Arctic and Antarctic tundra, the temperature acts as a limiting factor for them. Similarly, lack of vegetation is the limiting factor, which is responsible for the absence of herbivores from the Antarctic tundra. Limiting factors don't just dictate the distribution of species, but also govern their growth and abundance. If food availability is an issue, Arctic lemmings will continue to reproduce, but the litter size will be small. That, in turn, will control their population and bring it down to sustainable levels. There are quite a few biotic and abiotic factors that directly or indirectly affect the biodiversity levels of a tundra biome. We have discussed them below. A tundra biome may come across as devoid of life, but that is not the case. Despite these limiting factors, it has its unique blend of diversity. In winter, life does come to a standstill here. As the temperature falls, species like the Arctic ground squirrels and polar bears enter hibernation, while caribous and tundra swans migrate south to warmer areas with abundance of food. When caribous migrate, gray wolves follow them, as they are largely dependent on them for their dietary requirements. As a result, the region experiences a phase of darkness. In summer though, things return to normalcy and life flourishes in the biome, which otherwise seems devoid of life.