|
Assessment rationale:
The species is given a Red List status of Endangered [EN]. The extent of occurrence (EOO) and the area of occupancy (AOO) of Polystachya principia are estimated to be 601.1 and 12 km2 respectively, which fall within the thresholds for the Endangered category under subcriteria B1 and B2. The species is known from three occurrences, one in Cameroon and two on Príncipe Island (Sao Tome and Principe), which represent two subpopulations. Polystachya principia occurs in dense and high forest and in secondary forest in an old plantation, between 350−1,100 m elevation. It was collected within the Obò National Park, an area where most forests are intact and well managed. However, in Cameroon, the species habitat is threatened in the Kupe-Manengouba area by forest clearance for shifting agriculture at small-scale. Based on the most serious plausible threat which is shifting agriculture, the three occurrences represent two locations (sensu IUCN 2019), which falls within the thresholds for Endangered under subcriteria B1a and B2a. We project that this degradation will continue in the future. We infer a continuing decline in the area, extent, and quality of the species habitat, as well as in mature individuals of the species. Polystachya principia is thus assessed as EN B1ab(iii,v)+2ab(iii,v).
|