A comparative analysis of the past and present occurrences of some species of Paphiopedilum (Orchidaceae) in northeastern India using MaxEnt and GeoCAT

Abstract

Members of the genus Paphiopedilum are well known for their long-lasting unique flowers. They are becoming rare due to over-collection and habitat loss because of human disturbances and deforestation. The present study aimed to compare the past and present occurrences of the genus Paphiopedilum in northeastern India using MaxEnt and GeoCAT. A historical occurrence model (HOM) was prepared using secondary data, and an actual occurrence model (AOM) was constructed with primary field data. The HOM and AOM revealed that bioclimatic factors, topography and precipitation play a significant role in the survival of Paphiopedilum populations in northeastern India in both the current and historical distributions. The other vital environmental variables were elevation (h_dem), mean diurnal range (bio_2), annual mean temperature (bio_1), temperature annual range (bio_5) and annual precipitation (bio_12). The results showed a sharp decline in the extent of occurrence and the area of occupancy of Paphiopedilum in the study area. The extent of occurrence and area of occupancy for HOM were 170,972 km2 and 18 km2. For the AOM, they were 125,315 km2 and 12 km2, respectively. The HOM model indicated that Paphiopedilum was earlier growing sporadically. On the other hand, the AOM result indicates that it is presently growing sparsely in isolated pockets that are more prone to extinction. Paphiopedilum can be conserved successfully using an integrative conservation approach, comprising ecological modeling techniques to search for additional locations, ex situ propagation techniques, and possible reintroduction in selected areas.