Individually each of these components are important, but together even more so. All of the species combine, interact, and feed back upon each other to produce a myriad of greater, accelerated and cascading effects. It is not just species which are at stake, but whole ecosystems. Wild species play a vital role in maintaining the earth's ecological functions - the very air we breathe and the water we drink.

The UN has established the International Board for Plant Genetic Resources (IBPGR). They "promote an international network of genetic resources centres to further the collection, conservation, documentation, evaluation and use of plant germplasm". It has established a priority list of crops for concern.

Crops are in the list because of the level of risk to the crop and its wild relatives, the crop's economic and social importance, the materials that need collecting, the needs of the plant breeders, and the quality of present collections of crop diversity.

Elimination as well as extinction also decreases diversity. There is new phenomenon called McDonaldisation where a few species are now found all over the world. This has been bought about by much greater travel around the world. Examples include sparrows and magpies. They push out native species from their normal habitats, reducing diversity.

Click for priority list of crops