Abstract
The rapid spread of many weeds into intensely disturbed landscapes is boosted by clonal growth and self-fertilization strategies, which conversely increases the genetic structure of populations. Here, we use empirical and modeling approaches to evaluate the spreading dynamics of Tillandsia recurvata (L.) L. populations, a common epiphytic weed with self-reproduction and clonal growth widespread in dry forests and deforested landscapes in the American continent. We introduce the TRec model, an individual-based approach to simulate the spreading of T. recurvata over time and across landscapes subjected to abrupt changes in tree density with the parameters adjusted according to the empirical genetic data based on microsatellites genotypes. Simulations with this model showed that the strong spatial genetic structure observed from empirical data in T. recurvata can be explained by a rapid increase in abundance and gene flow followed by stabilization after ca. 25 years. TRec model’s results also indicate that deforestation is a turning point for the rapid increase in both individual abundance and gene flow among T. recurvata subpopulations occurring in formerly dense forests. Active reforestation can, in turn, reverse such a scenario, although with a milder intensity. The genetic-based study suggests that anthropogenic changes in landscapes may strongly affect the population dynamics of species with ‘weedy’ traits.
Highlights
The rapid spread of many weeds into intensely disturbed landscapes is boosted by clonal growth and self-fertilization strategies, which increases the genetic structure of populations
Clonal growth may lead to the maintenance of genetic d iversity[23,24], while continuous selfing can result in the absence of inbreeding depression as a consequence of purging of deleterious alleles over generations[16,25,26]
Based on seven microsatellite loci genotyped in a total of 224 individuals of T. recurvata hosted on 14 distinct trees, we observed moderate levels of genetic diversity within subpopulations, despite high endogamy and generally high genetic structure
Summary
The rapid spread of many weeds into intensely disturbed landscapes is boosted by clonal growth and self-fertilization strategies, which increases the genetic structure of populations. Clonal growth may lead to the maintenance of (once established) genetic d iversity[23,24], while continuous selfing can result in the absence of inbreeding depression as a consequence of purging of deleterious alleles over generations[16,25,26] These effects lead to a strong population subdivision, creating a metapopulation dynamic with extinction in a site being balanced by recolonization. This dynamic may, favor selfing and clonal genotypes, due to their higher capacities of recolonization[20,27]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have