Plant diversity is a common concern of humankind, and an essential resource for the planet. Two thirds of the world's plant species may be in danger of extinction in nature in the twenty first century. This threatens humankind's expectation of using plant diversity to build sustainable, healthy and better lives for the future. The World Conservation Monitoring Centre has already listed some 18,000 plant species as dangerously rare or threatened with extinction.
Of the roughly 250,000 kinds of vascular plants, probably no more than 1,000 have become extinct during the past century, but the pace of extinction is increasing rapidly at present and will almost certainly continue to do so over the next few decades. About a third of the world's vascular plants occur in temperate regions; here threatened and endangered plant species are in general well understood and well monitored. Conservatively, about 10% of the species in temperate regions might be classified as threatened or endangered, the greatest number of such species being in the Cape region of southern Africa. The greatest threat to plant species, however, exists in the tropics. About 170,000 species occur in the tropics and subtropics. Especially notable is the fact that more than 40,000 plant species - a quarter of the world's total diversity - occurs in the three northern Andean countries of Colombia, Equador, and Peru combined, countries in which the plants, animals and microorganisms are the most poorly known assemblage on earth.
The Gran Canaria Declaration (UNEP/CBD/COP/5/INF/32), and the resolution of the XVI International Botanical Congress, held in St.Louis, Missouri, United States of America, in August 1999 call for the development of a Global Strategy for Plant Conservation.
The Convention on Biological Diversity is the leading international convention for the conservation and sustainable use of biodiversity and recognizes the cross-cutting nature of plant conservation. The International Agenda for Botanic Gardens in Conservation, the Global Invasive Species Programme, and the Plants Programme of the IUCN Species Survival Commission all address plant conservation.
The Global Plan of Action for the Conservation and Sustainable Utilization of Plant Genetic Resources for Food and Agriculture and the International Undertaking on Plant Genetic Resources for Food and Agriculture developed by the Food and Agriculture Organization of the United Nations are concerned with plant conservation.