Fenología reproductiva y capacidad de regeneración de dos cardones, stenocereus griseus (haw.) Buxb. Y cereus repandus (l.) Mill. (cactaceae)

stenocereus griseus and cereus repandus are two of the most abundant and widely distributed columnar cacti in the arid and semiarid regions of venezuela. despite their value as keystone species for wildlife and their potential economic value, information on their reproductive activity and regeneration capacities is quite limited. these aspects were evaluated in natural populations from padre diego, lara state, and paraguana peninsula, falcon state. these cacti have broad time windows for reproduction and considerably high fecundity levels (s. griseus: 44,225 seeds/ind, c. repandus: 322,749 seeds/ind), which confer them great advantages in terms of natural regeneration and propagation. these species depend on nurse plants for their establishment. the highest percentages of survival occurred under the shadow of trees. under natural conditions, these species can produce half a ton of fruit pulp per hectare.