Distinct seeds in contrasting habitats: Morphological and reproductive responses in Butia eriospatha to new environmental conditions

Abstract

Distinct environments drive particular responses in the reproduction pattern of plants and may have ecological and evolutionary consequences for local populations. Currently, populations of the palm Butia eriospatha are found in forests and open grasslands in southern Brazil, providing opportunities to investigate how this species responds to recent habitat transformations. We assessed phenology and fruit morphology in two geographically close populations of B. eriospatha under contrasting environmental conditions – forest and open grassland – to address the following questions: 1) Are there phenotypic differences between populations of B. eriospatha occurring in contrasting habitats? 2) What ecological and evolutionary consequences could those differences impose on local populations? Greater variation was observed within the forest population. The grassland population showed lighter endocarps on average, reflecting a greater proportion of pulp per fruit, but smaller seeds, which may suggest plasticity, local adaptation, or both after the habitat transformation. Reproductive status is dependent on individuals' sizes in the forest environment but not for the open grassland population. Additionally, the average production of infructescences per individual is lower in the forest environment. Our findings indicate that the transformation of B. eriospatha's habitat has promoted important phenotypic changes. We emphasize the importance of forest environments in promoting dispersal selectivity, which may increase population fitness through time.