Search for a command to run...
(1) Vegetative activity and flowering and fruiting records are given for ninety-seven species from three vegetational belts in the andean (alpine) zone of the Cordon del Cepo (33017'S, 70016'W), Cordillera de los Andes, central Chile. Comparisons of phenological behaviour and overall phenological patterns were made at six altitudes between 2320 and 3550 m, including both northand south-facing slopes. (2) Nine categories of phenological behaviour and their altitudinal distribution are described. The percentage of summer-dormant species (dying back before the onset of winter) reaches a maximum at 2320 m (>75% of all species), and generally decreases with altitude. More summer-dormant species are present on north-facing (equatorial) slopes than on south-facing slopes. (3) The maximum growing season within the andean zone was 8 months at 2320 m altitude; the minimum growing season was 5 months on south-facing slopes at 3410 m. Shrubs and cushion plants had the longest period of vegetative activity, followed by perennial herbs and sub-shrubs, and then by geophytes and annuals. (4) Flowering in some species began before snowmelt, and continued until autumn, reaching a maximum in the austral summer between late December and late February at the altitudinal extremes. Peak flowering corresponded with the period of maximum temperature at lower altitudes, but was displaced after this period at higher altitudes and on south-facing slopes. (5) The average length of the flowering period for each species increased with altitude, approximately doubling over 1200 m altitude. Fruits of some species failed to mature both on some of the north-facing slopes and on most south-facing slopes in 1979. (6) Slower floral development at higher altitudes accounted for about two-thirds of the difference in the lengths of the flowering periods at the altitudinal extremes. (7) Checks in 1979-80 indicated that the phenological patterns detected in 1978-79 remained constant from one year to another. (8) The phenological behaviour of annuals, geophytes and some perennial herbs suggests that they may have been derived from the lower mediterranean matorral flora.