Seedling establishment of ferocactus acanthodes in relation to drought

Jordan P. W.; Nobel P. S.

The 30 smallest seedlings of F. acanthodes (Lem.) Britton et Rose (Cactaceae) at a canyon site in the northwestern Sonoran desert [California, USA] averaged 2.5 cm in height. Based on field studies of CO2 exchange throughout the year, the estimated time of their germination was late summer 1976. The length of lethal drought for seedlings of various ages was calculated from the seedling geometry (volume-to-surface ratio), dehydration tolerance and transpiration rates to explain the low rate of establishment. Individual years were identified which had sufficiently long growing seasons relative to the length of the subsequent droughts to allow establishment. Eight of the last 18 yr were suitable for establishment of F. acanthodes, the latest year being 1976.

Seedling establishment of ferocactus acanthodes in relation to drought

Jordan P.W.; Nobel P.S., 1981: Seedling establishment of ferocactus acanthodes in relation to drought. Ecology (Washington D C) 62(4): 901-906