Abstract
Wild-harvested plants are a globally valuable source of food and medicines and provide livelihoods for millions of people. Lophophora williamsii (peyote) is a small psychoactive cactus native to Mexico and Texas, USA, with considerable cultural, religious and medicinal significance to many indigenous peoples of North America. Peyote, like many plant species globally, is facing multiple threats and is in decline due to legal and illegal harvesting pressure as well as habitat conversion to grazing, agriculture and other economic land uses. Most published studies on peyote have focused on the plant’s anthropological, chemical and medical aspects. Surprisingly little is known about the ecology of this species, despite it being currently listed as Vulnerable on the IUCN Red List. Our study addresses this gap by providing the first detailed comparison of peyote populations growing in two distinct ecosystems in the USA: South Texas (Tamaulipan thornscrub) and West Texas (Chihuahuan desert). We highlight regional differences, whereby in West Texas plants at the surveyed sites plants were larger and densities were higher than in South Texas and note significant variability both within and between study sites. We also find significant effects of temperature and precipitation on plant size. Meaningful data about population size and structure across the range of habitats is the first necessary step in order to address a major conservation challenge of sustainable management of an overexploited resource. We conclude that urgent conservation and restoration efforts involving Native Americans and local landowners are needed to secure long-term survival of this vulnerable cactus.
