Phenology of two co-occurring Piper (Piperaceae) species in Brazil

Abstract

The co-occurrence of some species, including members of the Piper genus, has been shown to be associated with phenological factors. In the present study we analysed vegetative (sprout production and leaf flush) and reproductive phenophases (spike production, flowering, spike abortion, fruiting and dispersed spikes) of the co-occurring species Piper gaudichaudianum Kunth and Piper vicosanum Yunck. and checked the influence of abiotic factors on their phenological behaviour. Our study addressed natural populations in a semi-deciduous seasonal forest in south-eastern Brazil. In both species, the phenophases occurred mainly in the rainy season, were seasonal and associated with environmental variables, especially day length. However, sequential flowering and fruiting isolated them temporally from each other. Other differences were the growth of sexually reproductive sprouts (45.7% of the total sprouts) and the production of latent spikes in P. vicosanum; in P. gaudichaudianum, only 7.1% of the sprouts produced spikes that were not latent. Spike abortion was high: 73.8% (n = 474) in P. vicosanum and 84.8% (n = 231) in P. gaudichaudianum. The remaining spikes with fruits dispersed, on average, 293 and 1168 seeds per spike respectively. Although annual phenological behaviour of the species is regulated by similar environmental variables, their distinct reproductive strategies seem to favour the maintenance of the co-occurring populations.