Sprouting ability across diverse disturbances and vegetation types worldwide

Abstract

1 A widely used classification of plant response to fire divides species into two groups, sprouters and non-sprouters. In contrast, regeneration responses to catastrophic wind throw and small gap disturbance are more often considered a continuum. 2 We determined general patterns in the distribution of sprouting ability across species with respect to disturbance type and intensity, vegetation type and phylogeny and assessed the adequacy of a dichotomy for describing species' sprouting responses. These are important steps if sprouting is to be adopted widely and consistently as a functional trait. 3 Quantitative data were compiled from the literature and differences in species' sprouting proportions between disturbance classes were assessed using simple sprouting categorizations, visually using histograms and with mixture models. 4 The sprouter/non-sprouter dichotomy effectively characterized intense disturbances, such as fires resulting in stem-kill (peaks at 13%, 79% probability of sprouting). But there was a continuum of responses following less intense disturbances. Where substantial above-ground tissue was retained, as for wind throw, localized gap disturbances and low intensity fires, there were fewer non-sprouters and more intermediate sprouters. 5 Comparisons across diverse vegetation types and disturbances require quantitative records of sprouting, although the simple sprouter/non-sprouter dichotomy was sufficient for comparisons within fire. Patterns appeared consistent across broad vegetation types. Sprouting ability showed little phylogenetic conservatism.