Diversity and conservation in the cactus family

Abstract

Cacti are conspicuous elements of the Western hemisphere. They have long attracted attention due to their peculiar biology, and have maintained close relationships with local settlers. Cacti are used as food, fodder, medicinal and ornamental plants, and as a source of wood. The greatest diversity of this family is recorded in Mexico, with 586 species, followed by Brazil, Argentina, Bolivia and Peru. These countries are also the richest in endemic species. The underlying factors affecting diversity patterns are varied and include temperature, rainfall and geological history. Cacti are threatened by loss and degradation of habitat, and illegal collection. Though it is commonly stated that many species are endangered, most have not yet been evaluated. Due to the growing impact of human activities on biodiversity it is necessary to increase conservation actions to preserve this interesting group of plants, especially in South American countries where knowledge and conservation of cacti are still incipient.