Which terrestrial and marine environments characteristically contain few species? Explain why each of these environments has a low diversity.

Arctic tundra is an extremely cold, windy, and low precipitation environment characterized by permafrost, a permanently frozen subsoil. The harsh conditions make it difficult for most plant and animal species to survive, which leads to low species diversity in this environment.

There are several factors contributing to the low diversity in the arctic tundra, including: 1. Extreme cold: The low temperatures in the arctic tundra limit the range of plant and animal species that can survive in this harsh environment. 2. Short growing season: The short growing season means plants have a limited amount of time to grow, reproduce, and store energy, making it difficult for many species to thrive. 3. Low nutrient availability: The presence of permafrost and the slow rate of decomposition in cold environments result in low nutrient availability for plants.

The deep sea, which is found at depths below 200 meters, is known to contain few species. It is a dark, cold, and high-pressure environment where the availability of sunlight and nutrients is extremely limited. The unique conditions of the deep sea make it challenging for most marine species to survive, leading to low species diversity.

Factors that contribute to the low diversity in the deep sea include: 1. Lack of sunlight: Sunlight is crucial for photosynthesis, which is the base of the food chain in marine ecosystems. The absence of sunlight in the deep sea limits the primary productivity and, subsequently, the number of species that can survive in this environment. 2. High pressure: The weight of the overlying water column creates high pressure in the deep sea, which affects the physiology and survival of marine organisms. 3. Low nutrient availability: Nutrients in the deep sea are limited, mainly due to the absence of primary production and the reliance on the "marine snow" – organic matter falling from the surface – as the primary source of nutrients. Overall, it is the challenging environmental conditions in both the arctic tundra and the deep sea that result in low species diversity in these environments.