The variety of life on Earth, is its biological diversity. The number of species of plants, animals, and microorganisms, the enormous diversity of genes in these species, the different ecosystems on the planet, such as rainforests and coral reefs are all part of a biologically diverse Earth.
Why is Biodiversity important? Biodiversity boosts ecosystem resilience where each species, no matter how small, all have an important role to play for continued ecosystem survival. From a human perspective, from common drugs to possible cures for cancers, most of our medicine come from plants, many of which are now endangered. The current extinction rate is now approaching 1,000 times the background rate and climbing.
Just as biodiversity is now seen as the cornerstone of the resilience of natural world, so having a broad variety of agricultural crops is essential to the resilience of agriculture. Different species of plants are often able to cope with widely differing environmental conditions and many obscure varieties could hide vital disease resistance.
But the world's valuable diversity is disappearing incredibly fast.
As global markets have grown and seed production and agriculture become more commercialized, the old system of farmers saving their own seeds – and by doing so a myriad of different crops, often closely adapted to local conditions – has almost disappeared.
As a result variety is dwindling towards a vanishing point. China has lost 90 percent of the wheat varieties it had just 60 years ago. In the United States more than 90 percent of fruit tree and vegetable varieties found in farmers' fields at the beginning of the twentieth century are no longer there. Mexico has lost 80 percent of its corn varieties. India has lost 90 percent of its rice varieties.
Seed saving, planting and eating heirloom varieties becomes increasingly important as a way to preserve genetic diversity locally and globally. Through seed saving networks gardeners can access and share a much wider range of edibles than are commonly available commercially.