Although most cacti that have been studied are long lived, following individually marked plants in Boulder County, Colorado, for >7 years, we determined that average life span of Opuntia macrorhiza, the western prickly pear, is 3 years. A few individuals probably live >10 years. Vegetative reproduction, produced by rooting of cladodes, exceeded reproduction by germination and establishment from seeds. Both types of new recruits, from vegetative reproduction and seeds, had higher death rates than established plants. Size and frequency of flowering increased with age, although size both increased and decreased, sometimes dramatically, between years. Flowering correlated more strongly with size than with age. Estimates of population growth indicated these populations were stable (λ = 1.02). Elasticities suggest that the population was most sensitive to survival of smaller plants.
How to translate text using browser tools
1 June 2011
Population Dynamics of the Western Prickly Pear, Opuntia macrorhiza (Cactaceae)
Kathleen H. Keeler,
Brigitte Tenhumberg
ACCESS THE FULL ARTICLE
![](/ContentImages/journals/swna/56/2/2/WebImages/00384909-56.2.cover.jpg)
The Southwestern Naturalist
Vol. 56 • No. 2
June 2011
Vol. 56 • No. 2
June 2011