Resprouting and growth dynamics after fire of the clonal shrub Andira legalis (Leguminosae) in a sandy coastal plain in south-eastern Brazil

Abstract

1. Survival, resprouting and growth dynamics of the clonal shrub Andira legalis were studied for 2 years after fire, on a sandy spit on the coastal plain of Brazil. We examined the importance of resprouting for post-fire persistence, the relationship between resprouting patterns and injury suffered and size of individuals, and whether ramet growth was determined by competition and self-thinning. 2. Post-fire resprouting was responsible for production of new ramets and led to an increase in the mean number of ramets per A. legalis individual. 3. There was a negative association between resprouting from overground vs. underground. Highly injured individuals showed a significant tendency to sprout new ramets from underground organs whereas less damaged plants produced new branches and leaves from stem buds. Ramet production was related to an individual's prefire size (basal area), but to a lesser extent than to injury. 4. Immediately after fire, the G(t,x) function (mean of absolute growth rates of shoots of size x at time t) was size-independent, suggesting an absence of competition. G(t,x) then became size-dependent, while D(t,x) (variance of absolute growth rates of shoots of size x at time t) remained size-independent, indicating that any competition between ramets was symmetric. 5. Size-dependent mortality and a negative linear relationship between mean ramet size and density indicated self-thinning. However, the low ramet mortality (7.7%) and the absence of size hierarchies (coefficients of variation remained constant) suggest that competition and self-thinning were not intense.