Yucca schidigera

Most plant parts of Yucca schidigera have uses which have caused its over exploitation throughout its range in Mexico for the food and pharmaceutical industries. The plants are either extracted completely or a few trunks are left. The latter does not kill the plants; however, it has a negative impact on other aspects of its life cycle such as the number of inflorescences it produces and the age and frequency of reproduction. In addition, the pollination cycle is affected as the obligate pollinator of this species is also impacted by the extraction of the yucca. The yucca moth deposits its eggs in the yucca flowers and the larvae feed on the seeds inside the fruits. When the flowers and/or fruits are removed with the rest of the plant, so are the eggs and larvae of the moth. Also, the taller trunks of the plants are more frequently removed and these tend to be the ones that produce the most flowers, thus as a result of the extraction less flowers are available for the moth's life cycle (M.C. Arteaga pers. comm. 2020). Recruitment of new individuals of this species is very low in the Baja Peninsula and therefore the extraction of mature individuals are likely to have severe impacts on the long term survival of the species (M.C. Arteaga pers. comm. 2020). In recent years, subpopulations in southern California and Arizona have been impacted by solar farms construction, urban development, and cattle ranching. During dry seasons, small plants and seedling are the only source of food to cattle which also impacts the recruitment of new individuals in the yucca population.

The Mojave Yucca occurs in Joshua Tree National Park and Mohave National Preserve, in California, Grand Canyon-Parashant in Arizona, Lake Mead National Recreation Area, and Red Rock Conservation Area in Nevada, USA and San Pedro Martir National Park, Baja California, Mexico. In Baja California several commercial plantations have been established (Castellón-Olivares et al. 2002); however, it will take decades until these plants can be harvested (M.C. Arteaga pers. comm. 2020).