Orchids are particularly sensitive to environmental changes due to their narrow ranges in secondary-successional habitats, and partially cryptic which impede the observation during monitoring. Here Vogt-Schilb et al. investigated how habitat change can impact orchid spatio-temporal distributions in Corsica, while taking into account imperfect detection.
Two field surveys conducted 27 years apart (1982–1984 vs. 2009–2011) at the same 45 sites in Corsica show contrasting patterns in orchid dynamics at different spatial scales; while marked turnover of species composition was revealed locally, the regional species pool was maintained despite an overall increase in woody plant cover. The existing landscape mosaics of different ecologies maintain diversity at larger spatial scales. Furthermore, the study revealed great variation in detectabilities among orchid species and thus confirmed the relevancy of site-occupancy models accounting for imperfect detection.