Spatial Distribution Pattern and Interactions Facilitating of Lophophora Williamsii (Lem. Ex Salm-Dyck) J.M.Coult. (Cactaceae) in Tamaulipas, México

Abstract

In this study, the spatial distribution pattern of Lophophora williamsii (peyote) was determined through Ripley's K function and the facilitation interactions between the cactus and other species of the xeric scrub in southwestern Tamaulipas. Dasometric measurements of perennial plants were obtained in 10 plots of 100 m2. The frequencies of the associations between the peyotes and the facilitating species were obtained. The cardinal position of the peyotes under the canopy of the facilitator plant was recorded, as well as the temperature and radiation at ground level and under the canopy of the facilitators. Peyote presented an aggregate-type spatial distribution pattern, 97.7% of the sampled individuals presented association with facilitating species, among which Prosopis glandulosa (mezquite) stands out with 30.90%, Flourensia cernua (hojasén) with 24.70%, Larrea tridentata (gobernadora) with 19.15% and Agave lechuguilla (lechuguilla) with 16.11%. Significantly higher frequencies of peyotes positioned in the northern quadrant of the facilitator canopy were observed. Temperatures and solar radiation were significantly contrasting under the different associated species compared to open areas.

Keywords: peyote, nurse plant, xerophilic scrub