Climatic changes can drive the loss of genetic diversity in a Neotropical savanna tree species

Abstract

The high rates of future climatic changes, compared with the rates reported for past changes, may hamper species adaptation to new climates or the tracking of suitable conditions, resulting in significant loss of genetic diversity. Trees are dominant species in many biomes and because they are long-lived, they may not be able to cope with ongoing climatic changes. Here, we coupled ecological niche modelling (ENM) and genetic simulations to forecast the effects of climatic changes on the genetic diversity and the structure of genetic clusters. Genetic simulations were conditioned to climatic variables and restricted to plant dispersal and establishment. We used a Neotropical savanna tree as species model that shows a preference for hot and drier climates, but with low temperature seasonality. The ENM predicts a decreasing range size along the more severe future climatic scenario. Additionally, genetic diversity and allelic richness also decrease with range retraction and climatic genetic clusters are lost for both future scenarios, which will lead genetic variability to homogenize throughout the landscape. Besides, climatic genetic clusters will spatially reconfigure on the landscape following displacements of climatic conditions. Our findings indicate that climate change effects will challenge population adaptation to new environmental conditions because of the displacement of genetic ancestry clusters from their optimal conditions.

Carbon-optimised land management strategies for southern Amazonia

“…Indeed, its biodiversity is very high, including the existence of endemic species. However, its current state is also at risk of being irreversibly destroyed; a reduction of around 50% of its natural vegetation cover has been observed in the last decades (Beuchle et al 2015;Rocha et al 2011) and climate change is expected to add to this (Lima et al 2017). Although deforestation is still the dominant transition form, portions of the Cerrado are experiencing a recovery of secondary woody vegetation (Redo et al 2013).…”

A hierarchical Bayesian Beta regression approach to study the effects of geographical genetic structure and spatial autocorrelation on species distribution range shifts

“…This is because we can interpret the number of genetic clusters, their geographical distribution and their degree of admixture as the result of all demographic processes and adaptive forces acting on populations. This paradigm has steadily gained ground in studies estimating future distribution range shifts due to GCC by means of species distribution models (SDMs; Bálint et al, 2011;D'Amen, Zimmermann, & Pearman, 2013;Diniz-Filho et al, 2016;Gotelli & Stanton-Geddes, 2015;Ikeda et al, 2017;Jay et al, 2012;Lima, Ballesteros-Mejia, Lima-Ribeiro, & Collevatti, 2017;Marcer, Méndez-Vigo, Alonso-Blanco, & Picó, 2016;Milanesi et al, 2018;Yannic et al, 2014), stressing the need to consider the inherent genetic heterogeneity of organisms.…”

Establishment rate of regional provenances mirrors relative share and germination rate in a climate change experiment

“…Recent studies (e.g., Lima et al. ) modeled future climate scenarios predicting a significant loss of genetic diversity over longer time periods. Diversity loss is one of the major threats for species survival and finally may lead to local extinction (Lima et al.…”

“…Diversity loss is one of the major threats for species survival and finally may lead to local extinction (Lima et al. ). In conclusion, finding no or only low effects of climate change and land‐use treatments on the genetic diversity even emphasizes the importance and justification of establishing the GCEF as long‐term field experiment lasting for at least 15 yr. A distinct genetic response to anthropogenic environmental changes will be most probably measurable after a longer time period, by investigating subsequent plant generations.…”