Mortality of Transplanted Saguaro Seedlings

Only 26 of an original 800 5—cm—tall saguaros (Carnegiea gigantea) survived for 3 months when accessible to the rodents and rabbits at Saguaro National Monument, Arizona; after 1 year all of these small plants were gone. Although losses among a group of larger (15—cm—tall) seedlings were less abrupt, only one plant of an original 120 remained by the end of a year. When protected from these herbivores by cages, 12% of the smaller plants remained at the end of 1 year but only 2% after 5 years. Although browsing by rodents and lagomorphs quickly destroyed most uncaged small plants, the planting design probably accentuated the losses from the herbivores; in any event, many of these seedlings would soon have died from other causes.