1. The variety of living species. Animals, plants, bacteria, fungi and other microorganisms, 2. The genetic variation within a species or between species.
Conserving biodiversity is important to protect the health of ecosystems that sustain us. The reason is simple: the more biodiversity, the more likely that any of the existing varieties can survive an external pressure, for example a plague, a prolonged drought, extreme chemical pollution or the consequences of climate change.
Take the orange as an example. Imagine that there is a very strong storm one year exactly the most sensitive flowering season of a variety of orange. Wind and rain knock down all the flowers, completely eliminating production throughout the year. If there is only one variety of orange (there is absolutely nothing biodiversity), all organisms that depend on the orange can die or fall dramatically population.
Also known as: biodiversity, genetic diversity