The plant as a habitat structure
In the extremely dry Atacama, a large cactus introduces a complex surface into its surroundings. Flowers, fruits, spines and recesses between stems create different sites of organism activity. Cordero and colleagues studied relationships involving 19 coastal Copiapoa species using direct observation, camera traps and thermal imaging. [Cordero et al. 2026, abstract]
The relationships described encompass several trophic levels. A herbivore uses plant tissue, a predator may hunt animals visiting the plant, and another organism primarily uses its surface or shelter. This arrangement explains the description of Copiapoa as a focus of interactions between species. [Cordero et al. 2026, abstract]
Flowers, fruits and seeds
The authors recorded animals visiting flowers and organisms damaging their tissues. They also distinguished seed consumption before dispersal from seed transport by ants. Larvae developing inside fruiting structures may reduce the number of seeds leaving the plant. Dispersal by ants, meanwhile, moves diaspores through the surroundings. [Cordero et al. 2026, abstract]
An earlier review of the genus's biology described fruits opening at the apex and black, shiny seeds near which ants were observed. The 2026 study places this dispersal route in a broader system of feeding relationships. An animal's presence on a flower is described as a visit. Pollination effectiveness requires additional assessment of pollen transfer and seed set. [Larridon et al. 2015][Cordero et al. 2026]
A surface for lichens and other plants
The 2026 account includes epiphytic lichens, climbing plants and parasitic plants. Each group relates to the cactus differently. A lichen colonises its surface, a climber uses it as support, and a parasitic plant draws resources from the host. The abstract also describes animals eating the fruits of parasitic plants growing on cacti. This creates another route of food flow. [Cordero et al. 2026, abstract]
Thermal refuges
Thermography allowed the authors to assess the role of stems as shelters for ectothermic vertebrates. Daily temperature extremes were moderated within the cactus structure. An animal can use the difference between strongly sunlit surroundings and a sheltered place beside a stem. The abstract presents this effect qualitatively, without detailed temperature values for individual species. [Cordero et al. 2026, abstract]
Plant microclimate varies spatially. The 1980 study of stem orientation showed that a sunlit apex can warm considerably above air temperature. A thermal view of the whole plant thus includes both warm exposed surfaces and sheltered sites. Data from these papers concern different methods and observation scales. [Ehleringer et al. 1980][Cordero et al. 2026]
Ecological connections and plant loss
Removing a large cactus changes the local habitat structure, including the availability of flowers, fruits and shelters. This is an ecological consequence inferred by combining the interactions described with documented collection pressure. The 2024 study of threats to the genus analyses trade and poaching as important factors associated with risk assessment. [Villalobo-Lopez et al. 2024][Cordero et al. 2026]
Pressure may also act through stem damage. In the Freirina area, tissue tears in C. coquimbana were described and attributed to feral dogs. Such observations show that populations participate both in natural networks of relationships and in relationships altered by human activity. [Carevic and Barrientos 2022]
The discussion of the 2026 paper by Cordero and colleagues is based on the available abstract. The other cited publications were read in full.
Copiapoa cacti as multitrophic interaction hubs and thermal refugia in the hyper-arid Atacama Desert
Cordero S., Unamuno B., Escobar C., Vergara M. A., Roselló I., Villarroel J., Guerrero P. C., Copiapoa cacti as multitrophic interaction hubs and thermal refugia in the hyper-arid Atacama Desert, Journal of Arid Environments, 2026, 236:105659, doi: 10.1016/j.jaridenv.2026.105659
The study of 19 Copiapoa species documents associations with herbivores, flower visitors, predators, lichens and parasitic plants. Direct observations, camera traps and thermography also show the role of stems as thermal refuges for animals.
An integrative approach to understanding the evolution and diversity of Copiapoa (Cactaceae), a threatened endemic Chilean genus from the Atacama desert
Larridon I., Walter H. E., Guerrero P. C., Duarte M., Cisternas M. A., Peña-Hernández C., Bauters K., Asselman P., Goetghebeur P., Samain M. S., An integrative approach to understanding the evolution and diversity of Copiapoa (Cactaceae), a threatened endemic Chilean genus from the Atacama desert, American Journal of Botany, 2015, 102(9):1506-1520, doi: 10.3732/ajb.1500168
The study brings together three chloroplast DNA regions, morphology and the distribution of Copiapoa. It discusses species boundaries, recurrent similarities in growth form and the consequences of classification changes for threat assessment.
Orientation and its consequences for Copiapoa (Cactaceae) in the Atacama Desert
Ehleringer J., Mooney H. A., Gulmon S. L., Rundel P., Orientation and its consequences for Copiapoa (Cactaceae) in the Atacama Desert, Oecologia, 1980, 46(1):63-67, doi: 10.1007/BF00346967
The field study measures stem orientation and inclination in three historically recognised Copiapoa taxa, and their surface temperatures. A radiation balance model explains how northward orientation of the apex relates to warming of the growth and flowering zone.
Effects of trade and poaching pressure on extinction risk for cacti in the Atacama Desert
Villalobo-Lopez A., Peña C. M., Varas-Myrik A., Pillet M., Jahnsen P., Pliscoff P., Goettsch B., Guerrero P. C., Effects of trade and poaching pressure on extinction risk for cacti in the Atacama Desert, Conservation Biology, 2024, 38(5):e14353, doi: 10.1111/cobi.14353
The authors assess threats to Copiapoa taxa from their distribution and habitat pressures. The analysis compares the importance of trade, illegal plant collection and landscape condition. The results section gives counts for the threat categories.
Efectos de la introducción de fauna alóctona (Canis familiaris) en ecosistemas áridos: estudio de caso en cactáceas endémicas
Carevic F. S., Barrientos E., Efectos de la introducción de fauna alóctona (Canis familiaris) en ecosistemas áridos: estudio de caso en cactáceas endémicas, Idesia, 2022, 40(2):129-132, doi: 10.4067/S0718-34292022000200129
The study from the Freirina area compares damage to three cacti attributed to feral dogs. The authors assess the size of tears in stems and the number of damaged plants at two observation times in 2021.
