Conservation of exceptional stands of the giant cardon cactus in Baja California Sur, Mexico
The giant cardon cactus (Pachycereus pringlei) is the emblem of the Baja California peninsula. It is a majestic plant widely distributed over the entire peninsula and often occurring in dense stands. It is difficult to visit Baja California without being exposed to scenic views framed by this tree-shaped cactus. Because the peninsula is sparsely populated and many of its areas are remote and difficult to access, most populations of cardon have remained intact through five centuries of European settlement. The first description (1768) of cardon was by the founder of Mission San Javier, the Jesuit priest Miguel del Barco, near the town of Loreto.
At least two factors threaten populations of cardon in Baja California Sur. First, to establish and expand agricultural fields, entire stands are clearcut and bulldozed. Second is a phenomenon of cardon decline, whose exact cause is yet unknown (Bashan et al., 1995).
Because cardon is so widely distributed throughout the Baja California peninsula, it is not considered endangered. Yet, clearly there is a need to preserve some of the most magnificent stands for future generations. Because the combination of scenic beauty and remarkable specimens of cardons makes some sites particularly attractive, they deserve to be preserved as local, national, and international treasures.
General view of destruction of cardon stands at location no. 4 in 1998 and 1999
Close up of the destruction at the same area.
Natural decline of cardons
The giant columnar cardon cactus (Pachycereus pringlei) appears to have an ailment(s) that is destroying a large number of plants. The causal agent(s). whether biotic or abiotic, has yet to be determined. Two forms of symptom development have been recorded. The first is a circular tissue decay on a branch leading to death of the growing tip. In this case, the dead portion detaches and forms a "flat top" on the living part (hence the proposed name for this phenomenon). Progressive degeneration and death of the plant ensue. The second form is an initial circular crack on the branch without decay. Later, the green branch above the crack detaches, creating the characteristic flat top. A third type of degeneration was also observed: fatal bleaching. The time period between symptoms is unknown. It primarily affects mature, more then 100-year-old plants, but relatively young plants are also affected. Thirty-six field surveys covering the entire state of Baja California Sur found five major and four smaller centers of flat top decay. We believe that flat top decay syndrome of the cardon cacti in Baja California is common and widespread.
We describe here four sites in Baja California Sur that we believe it is urgent to consider for preservation before irreversible damage causes their disappearance.
The marked areas on this map of the southern half of the Baja California Peninsula include proposed cardon reserve areas. Select an area to zoom in for more detail.
Proposed reserve areas 1 and 2
Notice the perfect shape of cardons at this site.
Close-up of healthy side branch in unnamed wash north of Loreto.
Proposed reserve area 3
Arrow on map points to proposed reserve area.
Southern Bahia Concepcion has the tallest stands of Cardon detected in the survey. Note grown man at base of this sample.
Proposed reserve area 4
Huge specimen near Los Planes.
Arrow points to proposed reserve area.
Some facts about cardon cactus
The cardon is one of the most massive of all cacti. An average mature cardon may reach a height of ten meters, but individuals as tall as eighteen meters are known (León de la Luz and Valiente 1994). It is a slow growing plant (Roberts, 1989) with a life span measured in hundreds of years, but growth can be significantly enhanced in its initial stages by inoculation with plant growth-promoting bacteria such as Azospirillum sp. (Bashan et al., 1999; Carrillo et al., 2000; Puente and Bashan, 1993). Most adult cardon have several side branches that may be as massive as the trunk. The resulting tree may attain a weight of 25 tons (Gibson and Nobel, 1986). Adult cardon is adapted to the harsh climate of Baja California, characterized by drought and high temperatures, but as a seedling and juvenile it depends for survival on nurse plants, such as mesquite (Prosopis articulata) (Carrillo-García et al., 1999). In alluvial soils in southern Baja California, the cardons, and other cacti, occupy an extensive area.
Majestic cardon plant, the emblem of the Baja California peninsula. Note woman at base for size scale.
The Cardon as Ambience
Sunset over the desert
The cardon is an omnipresent facet of life in the Baja Peninsula. It surrounds us and permeates the very atmosphere with its presence.
Cardon over the Sea of Cortes
Although difficult to evaluate objectively the impact on the local society and such commercial aspects as tourism, it is undeniable that the disappearance of the cardon from the Baja Peninsula would forever change the face of this land, leaving a hole in the fabric of the world.
Reference for extra reading on cardon
First description of cardons from the 17th century
Mission San Javier, 34 km east of Loreto, established by the Jesuit priest Miguel del Barco in the 17th century and preserved intact to this day.
Additional reading on cardons