... reservesFrequency31–3515–187–1002–610203011– 14 Slope (°)(a)5152527–3023–2619–22Frequency3336– 348 32 744 –2891 244 8–259502299– 244 720 40 602596–2 743 Elevation (m)(b)1030503188–33353 040 –31872892–3039Frequency 240 1–26001201– 140 0 40 1–60000–200 40 80100801–1000Nearness ... SINGLE-SPECIES POPULATIONS 197••1.61 .4 1.21.00.850 40 3020100 40 32 24 1680Generation time (years)Age at maturity (years)1.61 .4 1.21.00.8600 45 03001500 40 32 24 1680Total ... 9,9 34 7,126 5,177 3,162Mammillaria polyedra 10,118 5,512 3 ,47 3 2,611Mammillaria sphacelata 3,956 5 ,44 0 2,803 2,580Neobuxbaumia macrocephala 2, 846 4, 943 3,378 1,9 64 Neobuxbaumia tetetzo 2,964...