干旱区生态环境知识资源中心

Background and Aims: The family Cactaceae possesses the largest number of species listed as endangered, but biological information as well as ecological studies are needed to assess the conservation status of cacti and apply guidelines to include or exclude species from red lists. Astrophytum ornatum has a status of vulnerable, but its ecological situation has not been evaluated, so its local and regional status is unknown. The aim of this study was to determine factors influencing the maintenance of their populations to provide information to establish their conservation status.

Methods: We analyzed the population structure, spatial distribution pattern and reproduction of A. ornatum in one remnant population in Cadereyta de Montes, Queretaro, Mexico.

Key results: The species has an aggregated spatial distribution pattern, which suggests an interaction with nurse species or cracks and rocks that provide shade. Individuals are concentrated in the first size categories, 34% were reproductive, large plants have a greater number of reproductive structures but with less seeds per fruit in comparison to medium-sized plants.

Conclusions: The studied population has a potential to grow because its population structure displays the typical form of species with common recruitment. This population structure, high density and the presence of small plants suggest that the remaining population of A. ornatum is in good condition; however, no recruitment of seedlings was observed, there is a high mortality in all size classes and the risks posed to the locality are its proximity to human settlements and sand banks. Global assessment suggests that A. ornatum should be considered a threatened species.