Biodiversity is the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems. Biodiversity boosts the productivity of an ecosystem. Each species, no matter how large or small, plays an important role in their habitat. Changes in one part of an ecosystem will affect other parts of the ecosystem. Higher variety of diversity creates more food and promotes symbiotic relationships(a mutually beneficial relationship) between species. This abundance helps to sustain life forms and ensure a healthy environment that can withstand and recover from disasters.