Ecosystems

Naiara and Rebeca

Living things in an ecosystem

Relationships between the physical

environment and living thingsThe physical environment affects the type of vegetation found in an ecosystem. Depending on the combination of climate, soil and terrain, an ecosystem can be made up of forest, grasslands or desert. The type of vegetation determines the types of animals that live in an ecosystem. For example, birds that build their nests in trees cannot live in grassland. In turn, living things can modify the environment. Rabbits and moles modify the terrain by digging burrows in the ground. Tree roots growing in rocky soil can break rocks over a long period of time.

Living things in an ecosystem

The physical environment of an ecosystem includes numerous factors that influence living things. These factors include temperature, humidity and soil. A physical environment can be terrestrial or aquatic.

In terrestrials environments the most important factors are climate, soil conditions and the terrain. The type of climate depends on various factors: temperature, humidity and the seasons.

In aquatic environments the most important factors are salinity (the amount of salt in the water), the amount of light, the water current, the temperature and the type of seabed or riverbed. Freshwater ecosystems contain very low levels of salt. Marine ecosystems contain higher levels of salt. Light depends on the depth and clarity of the water. This factor is important as plants and algae need light to grow.