Climatic drivers of leaf traits and genetic divergence in the tree Annona crassiflora: a broad spatial survey in the Brazilian savannas

Abstract

The Cerrado is the largest South American savanna and encompasses substantial species diversity and environmental variation. Nevertheless, little is known regarding the influence of the environment on population divergence of Cerrado species. Here, we searched for climatic drivers of genetic (nuclear microsatellites) and leaf trait divergence in Annona crassiflora, a widespread tree in the Cerrado. The sampling encompassed all phytogeographic provinces of the continuous area of the Cerrado and included 397 individuals belonging to 21 populations. Populations showed substantial genetic and leaf trait divergence across the species' range. Our data revealed three spatially defined genetic groups (eastern, western and southern) and two morphologically distinct groups (eastern and western only). The east-west split in both the morphological and genetic data closely mirrors previously described phylogeographic patterns of Cerrado species. Generalized linear mixed effects models and multiple regression analyses revealed several climatic factors associated with both genetic and leaf trait divergence among populations of A. crassiflora. Isolation by environment (IBE) was mainly due to temperature seasonality and precipitation of the warmest quarter. Populations that experienced lower precipitation summers and hotter winters had heavier leaves and lower specific leaf area. The southwestern area of the Cerrado had the highest genetic diversity of A. crassiflora, suggesting that this region may have been climatically stable. Overall, we demonstrate that a combination of current climate and past climatic changes have shaped the population divergence and spatial structure of A. crassiflora. However, the genetic structure of A. crassiflora reflects the biogeographic history of the species more strongly than leaf traits, which are more related to current climate.

Drivers of bromeliad leaf and floral bract variation across a latitudinal gradient in the Atlantic Forest

“…Two major clades splitting V. taritubensis (green, yellow and blue) and V. incurvata (red) specimens are recovered. Our results contrast to the pattern of a decrease in size at sites with lower rainfall and hotter temperatures with increased irradiance (Peppe et al, 2011;Ribeiro et al, 2016;Wright et al, 2017), but is consistent if interpreted in a more comprehensive way regarding plant architecture. For localities number see Table S1 in Appendix S2 [Colour figure can be viewed at wileyonlinelibrary.com] global assessment of climatic drivers of leaf size demonstrated no effective thermal constraint acting in warm and ever-wet tropical climates, as sufficient water is commonly available for transpirational cooling and plants are not exposed to frost damage (Wright et al, 2017).…”

“…Being large leaved at seasonal sites with lower mean annual precipitation is advantageous if this size translates into wider blades and sheaths to form a robust tank to retain water. Our results contrast to the pattern of a decrease in size at sites with lower rainfall and hotter temperatures with increased irradiance (Peppe et al, 2011;Ribeiro et al, 2016;Wright et al, 2017), but is consistent if interpreted in a more comprehensive way regarding plant architecture.…”

Nitrogen and Potassium Fertilization in the Initial Growth of Annona crassiflora Mart.

“…However, with the rapid expansion of agriculture in Cerrado regions accompanied by reduction in native vegetation, many species of this domain are threatened, including A. crassiflora. Thus, in order to minimize environmental impacts and promote maintenance of the native vegetation, programs for the recovery of these disturbed areas are necessary (Ribeiro et al, 2016b). Accordingly, it is also necessary to understand the silvicultural behavior of this species, mainly in relation to fertilization, considering that little is known about the behavior of this species in Cerrado regions.…”

Geographical variation and the role of climate in leaf traits of a relict tree species across its distribution in China

“…; Ribeiro et al . ). In particular, most morphological trait (leaf perimeter, width, thickness, petiole length and length–width ratio) variation values were less at the regional scale than the local scale, which might be linked with adaptation to broad environmental gradients (Craine et al .…”

“…A study in Brazilian savannas showed that leaf trait divergence in Annona crassiflora was induced by climate variables (Ribeiro et al . ). Niinemets () found a within‐species leaf economics spectrum in Quercus ilex, and found within‐species trait–climate relationships were different from the general spectrum for all species.…”