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We measured annual growth
increments on 77 individuals of Lemaireocereus aragonii, a columnar cactus growing at Palo Verde. Most of
the height growth of this cactus occurs during the dry
season when most of the canopy trees are leafless. Relative
growth rates of L.
aragonii varied considerably
among years. The variation in growth was directly related to
the total precipitation of the previous year and inversely
related to the amount of precipitation that occurred during
the dry season. El Nino years produce conditions unfavorable
to the growth of L.
aragonii: low total rainfall may
inhibit moisture recharge following the previous dry season,
and high dry season precipitation may result in increased
leaf retention in canopy trees (resulting in lower light
levels).
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Waxy bands deposited yearly make
it possible to measure the annual height growth of
L. aragonii
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