Analysis of plant richness and conservation value of the three areas added to the Pedregal de San Angel Ecological Reserve, Federal District (Mexico)

We evaluated the plant richness and conservation value of three areas recently added to the territory of the Pedregal de San Angel Ecological Reserve: two of them added to the Southeastern core area (SO1 and SO2), and one to the buffer zone called A13. Cumulative plant richness was 199 species (57.6% of the species previously recorded in the literature). In SO1, SO2 and A13, the numbers of recorded plant species were 148, 152 and 149, respectively. Mammillaria haageana subsp. san-angelensis, which is an endangered cactus species, Bletia urbana, a threatened orchid, as well as a two new records for this site (Eupatorium pazcuarense and Adiantum andicola) were found in A13. Pennisetum clandestinum is an introduced species that occurs in disturbed areas of this reserve. With these three species, the total plant richness of the reserve goes up to 340 taxa. Based on a conservation value index calculated on the basis of eight parameters, A 13 showed the highest value (21 points), followed by SO2 and SO1, with 16.5 and 10.5 points, respectively.