Climatic conditions may structure the distribution of Syzygiella rubricaulis (Nees) Steph., a disjunct and high elevation species

Abstract

Syzygiella rubricaulis is a widely distributed species in the high mountains of tropical America and in addition occurs on the Azores. In order to unravel the climatic environment of S. rubricaulis populations, we compiled georeferenced data from verified herbarium specimens, GBIF (Global Biodiversity Information Facility – www.gbif.org) and species Link (www.splink.org.br) databases, as well as climatic data from Worldclim, to determine the climatic signals structuring the populations. We analyzed the disjunct range of Syzygiella rubricaulis from a climatic perspective. We used cluster analysis and principal components analysis (PCA) with climatic variables to clarify how climate may be structuring populations and which variables make the largest contributions to dataset variations. We recovered three major strongly supported groups of S. rubricaulis. Water vapour pressure, minimum temperature of the coldest month, annual precipitation, and precipitation of the wettest month explained variation patterns in the dataset best. We also provide a detailed dataset characterization of all records compiled in the present study. Our findings provide new insight into how climate structures the distribution of S. rubricaulis populations. Precipitation variables play an important role in determining the observed distribution patterns of the species and are suggestive of future alteration of its geographic distribution in response to climate change.