Conservation of Cacti

Many cacti are adversely affected by human activities, through habitat destruction and collecting from the wild, for example. In some cases entire populations have been destroyed and lost, and in others the number of plants has been drastically reduced. Examples of such losses are numerous throughout Latin America and the United States. One of the most widely cultivated and appreciated barrel cacti is the golden barrel cactus. Unfortunately, the natural habitat of Echinocactus grusonii has been nearly destroyed by the construction of a large dam near Zimapan, Mexico.

Only a few of these magnificent cacti now survive on the steep slopes above the new reservoir. The Mexican government wisely allowed an extensive salvage operation by the Universidad Nacional Autónoma de México to take place before the valley was flooded, and hundreds of individuals were saved. The Mexican government is improving its major highways, but many of these wide superhighways cut through desert terrain with rare cacti. For example, just north of the city of San Luis Potosí a new highway destroyed one of the finest populations of Pelecyphora aselliformis.

Salvaged golden barrel cacti, Echinocactus grusonii, Mexico

Echinocactus Grusonii HabitatDesert Cactus New Mexico
Cacti marked for salvage near Phoenix, Arizona

Again, the government sensibly allowed an extensive salvage operation in which several hundred plants of both P. aselliformis and Mammillaria au-reilanata were transplanted to El Charco del Ingenio Botanic Garden in San Miguel de Allende before the bulldozers arrived.

Similar salvage operations have taken place in the United States. As urban development alters vast expanses of the Sonoran Desert near Tucson and Phoenix, Arizona, nurseries are licensed to remove and sell specimens of the saguaro, Car-negiea gigantea, and other native cacti. The staff of the Desert Botanical Garden was allowed to salvage hundreds of individuals of Echinocactus hor-izonthalonius var. nicholii on private land that was about to be altered in a mining operation. The Navajo Tribal Council and the federal government have allowed the salvage of rare cacti on the reservation that were threatened by highway construction. Unfortunately, salvage operations have not always been possible, and important populations of cacti have been lost. Urban expansion and freeway development just north of Albuquerque, New Mexico, destroyed some of the richest populations of Sclerocactus papyracanthusbecause developers did not contact groups willing to undertake the task of locating and removing the plants.

Dried Saguaro Cactus For Sale
Carnegiea gigantea, saguaro, for sale in Phoenix, Arizona

The rapidly increasing population of Mexico has meant that more and more marginal land is being converted to agriculture. Silt plains in the state of San Luis Potosí are cultivated for crops of maize, and populations of Ariocarpus kotschou-beyanus plowed up in the process. Other examples of the loss of populations of rare cacti through habitat destruction for agriculture in Mexico are Echinocereus knippelianus, E. pulchel-lus, and the creeping devil of Baja California, Ste-nocereus eruca. The vineyards and fruit orchards of the Elqui Valley of Chile have expanded onto the slopes of the valley, destroying extensive populations of Copiapoa and Eulychnia. Groves of nonnative Eucalyptus have also been planted to provide poles and stakes, destroying much of the natural cactus population.

Introduced animals have severely affected populations of cacti in many arid regions of the New World. Goats destroyed numerous endemic species of plants, including cacti, in the Galápagos Islands, and considerable expense and time


Echinocactus hori-zonthaloniusvar. mcholii salvage operation north of Tucson, Arizona, by the Desert Botanical Garden

San Luis Valley Arizona

Cultivated land, with habitat of Ariocarpus kotschoubeyanus in the background, east of El Huizache junction. San Luis Potosí, Mexico

Elqui Valley
Elqui Valley, Chile

Browningia candelaris in the Tinaja Valley, Peru

Browningia Candelaris

Browningia candelaris in the Tinaja Valley, Peru

Damaged Cactus From Animals That

have been spent attempting to eradicate them and other introduced animals. Populations of cacti in Mexico are damaged by goats. One of the most disturbing effects of animals can be seen in the populations of Browningia candelctris in Peru. Livestock are periodically allowed to graze in areas with these magnificent cacti, but the animals have destroyed all young plants less than 2 m (6.6 ft) high. There simply are no young individuals of this species, which means that the long-term survival of B. candelaris is in doubt.

In other cases, losses of wild cacti have been the result of human greed—the desire to reap financial benefits at the expense of the survival of rare cacti. I visited the type locality of Pelecyphora strobiliformis, an isolated hill near Miquihuana in the Mexican state of Tamaulipas, in the early 1960s. The population was so dense with plants of all ages that it was nearly impossible to avoid walking on them. Six years later I returned to the same hill and found the rich population gone. Nearby villagers came to meet us, many with hands full of cacti for sale. One man told us that a gringo (Anglo) had come with a large truck the year before and hired them to remove all the plants from the hill. They were paid a peso for each plant they dug out for him. The villagers were efficient, for virtually all the plants, young and mature, had been dug up and hauled away for sale in Europe. Thirty years later the hill was still without this interesting cactus, though an unconfirmed report has been received that a few seedlings have been found. Perhaps the seed reservoir will someday replace the plants lost to human greed.

Twice I have come across piles of dying cacti in Texas that were dug out of the ground by commercial collectors but then left for some reason. Illegally collected barrel cacti and saguaros, Car-negiea gigantea, can occasionally be found for sale in European nurseries. I have seen these, for example, on the island of Sicily. I have also visited immaculate greenhouses in Japan with large collections of field-collected Ariocarpus. Most hobbyists are willing to purchase nursery-propagated plants, as indeed should anyone be who is truly interested in cacti and understands the need to preserve them in the wild.

My colleagues and I discovered a small pile of Ariocarpus bravoanus subsp. hintonii that had been dug up but left behind because parts of the

Illegally collected cacti in Villa de la Mina, Texas

Illegally collected Eriosyce in Chile

Dug-up Ariocarpus bravoanus subsp. hintonii in San Luis Potosi, Mexico

Illegally collected Eriosyce in Chile large roots had been broken off when they were removed from the rocky ground. I have observed similar cases where specimens of A. agavoides and Pelecyphora aselliformis have been dug up and then apparently forgotten.

Illegal collecting of cacti in the United States, Mexico, and other countries continues in spite of laws prohibiting it. The loss of important populations of cacti is real, despite the efforts of conservation groups, national hobbyist societies, and

Dug-up Ariocarpus bravoanus subsp. hintonii in San Luis Potosi, Mexico

Ariocarpus collection in Japan

Ariocarpus Collection

Ariocarpus collection in Japan government regulations to prevent it. Continuing efforts must be made to educate people that collecting from the wild and habitat destruction jeopardize the survival of these magnificent plants, not to mention the animals that depend on them in many instances.

There are three main methods of conserving cacti. The first is simply leaving the plants, undisturbed, in their natural habitats. The second is the setting aside of nature reserves or other protected areas that have rare plants or other natural resources to be conserved. Both of these methods conserve the rare plant and its habitat at its locality and are known as in situ, on-site, conservation (P. F. Hunt 1974). The third method is ex situ, off-site, conservation and can be considered as a kind of extra insurance against extinction of the species.

Continue reading here: In Situ Conservation

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