Changing Environments (Triple Only)

Environmental changes, can significantly alter the distribution of species within ecosystems. These changes can be SEASONAL (variations in temperature and water availability with the seasons), GEOGRAPHICAL (influenced by the specific characteristics of land and water in a region) or caused by HUMAN INTERACTION (altered habitats through urban development, pollution, and climate change).

Factors Affecting Species Distribution

 1. Temperature

Species have specific adaptations that allow survival within certain temperature ranges. With climate change causing global temperatures to rise, species are migrating to new areas that have cooler conditions.

 2. Availability of Water

All organisms require water either directly for survival or indirectly as it supports the entire food web. For example, the annual migration of wildebeest in Africa is heavily influenced by the availability of water, which dictates their grazing routes.

 3. Composition of Atmospheric Gases

OXYGEN is crucial for AEROBIC RESPIRATION in both land and aquatic species.

In aquatic environments, HIGH OXYGEN LEVELS are necessary for the survival of many species. As WATER POLLUTION increases, growth of microorganisms can lead to a drop in oxygen when they die as a result of decomposition. Fish CANNOT survive in these conditions.

On land, CARBON DIOXIDE levels impact PHOTOSYNTHESIS in plants. Changes in CO2 concentrations can affect the growth and distribution of plant species. Additionally, pollutants like sulfur dioxide can prevent certain species, such as lichens, from surviving in heavily industrialized areas.