Farms and roads break up large ecosystems into small, isolated fragments. This decreases the amount of organisms left in the remaining sections because:
- It may be difficult for species to disperse from one fragment to colonise a new one if they are far apart.
- Some plant species may be cut off from their pollinators so can't reproduce.
- The food chains within the ecosystem may collapse
- The population left in the fragment may be too small to recover from things such as fires or floods.
- The remaining fragment may not provide access to food, water and shelter needed for survival.
Research shows that increasing the size of an ecosystem by a factor of 10 doubles the number of species within it. Larger sites are important for biodiversity.
Wildlife corridors are needed to help animals to move from one habitat to the next. This is especially important for wildlife to migrate during climate change.