Structure and development of a Scalesia pedunculata stand in the Galapagos Islands

Stands of Scalesia pedunculata in the Galapagos Islands often develop as single-aged cohorts following episodes of mass death and regeneration. We updated earlier studies on a stand that had regenerated soon after the 1982–3 El Niñoevent. We quantified stem size distribution and dispersion pattern in a 0.56 ha plot near Los Gemelos on Santa CruzIsland. The plot was dominated (95% of basal area) by S. pedunculata. The stem size distribution showed the increasedmean and variance for diameter (since 1987 and 1991) expected of an aging stand. Stems averaged smaller than in1981, just before the last mass mortality episode. Large S. pedunculata stems were regularly dispersed while smallerstems were clumped and negatively associated with larger stems, implying that intraspecific competition may beimportant in structuring the stand. CDF Contribution Number 1008.