Ecophysiology of the pitayo de Queretaro (Stenocereus queretaroensis)

Pitayos (Stenocereus spp.) are columnar cacti native to subtropical regions of Mexico that produce edible fruits. Vegetative and reproductive growth for S. qureretaroensis occurs in the dry season but not simultaneously. Most daily net CO2 uptake by S. queretaroensis occurs at night, with the highest values during the late autumn and early winter dry season. Its fine roots are colonized by arbuscular mycorrhizal fungi that enhance stem and fruit growth, apparently due to better P nutrition. The seeds are small, and germinate in response to light. The fruits of S. queretaroensis are valuable resources to wild animals, and can help sequester atmospheric carbon during the dry season.