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Cacti are an abundant taxa in the Sonoran Desert, but most research focuses on their population dynamics and physiology and relatively little is currently known regarding their role in desert biogeochemical cycles, particularly regarding their decomposition dynamics. A better understanding of cactus decomposition and their role in ecosystem processes is important, considering there are many threatened and endangered species within this group. In this study, we decomposed two common species of cacti, Opuntia chlorotica (pancake prickly pear) and Cylindropuntia acanthocarpa (buckhorn cholla), in the Sonoran Desert of Arizona, U.S.A. Mass loss, water loss, nutrient content, and structural and metabolic chemistry were measured at regular intervals over the course of one year of decomposition. Our results demonstrate the contribution of cactus decomposition to carbon and nutrient recycling, with dynamics that are overall comparable to those of woody and herbaceous leaf litter for most elements. We enumerate, however, a particularly important role in calcium dynamics in comparison to woody and herbaceous leaf litter. Despite different structural characteristics, both cactus species released nutrients at a statistically equivalent rate, though with altered timing of net immobilization and mineralization due to temporary mass gain and associated nutrient immobilization in cholla. The release of nutrients and water from decaying cacti have a modest influence on underlying soil CO2 flux, secondary to a more dominant influence of overall soil temperature and moisture. Thus, our data provide a baseline for understanding the decay dynamics of two common cactus species and suggest that, while there is still a lack of information pertaining to cactus decomposition, the similarities between leaf litter and cacti will aid our predictions of the consequences of future changes in cactus populations.