Microenvironmental drivers and phorophyte associations shaping the distribution of the national orchid Cattleya trianae in an educational campus of Colombia

Epiphytic orchids, which represent between 67 and 70% of the Orchidaceae family, have developed remarkable adaptations to thrive in irregular canopy environments in tropical and subtropical forests. Cattleya trianae , in particular, shows different zones of spatial distribution in urban sites due to anthropogenic actions, which have been little studied. This research article shows the relationship between microenvironmental characteristics and distribution in five different zones characterizing orchid diversity including an urban forest in the municipality of Garzón, Colombia. In the present study a systematic stratified sampling design was implemented, taking into account two heights (1.5 and 3.5 m) for microclimatic parameters in the phorophytes. Multivariate analyses revealed that the abundance of Cattleya trianae was significantly correlated with microenvironmental conditions, particularly relative humidity ( > 80%) and moderate temperatures (∼23°C) daily averages during specific seasonal winter peaks. In the case of the correspondence analysis, significant associations were found between the characteristics of the phorophytes (texture and canopy architecture) and Cattleya trianae . In addition, the highest abundance of orchids above 40 individuals/10 m 2 was found in areas with higher dew rates (0.15 mm/h). This provides important information for the conservation of the orchid Cattleya trianae in urban environments and contributes to the understanding of the factors that influence the spatial distribution of the orchid Cattleya trianae in ecosystems modified by humans.