Colonization patterns of the invasive Brazilian peppertree, Schinus terebinthifolius, in Florida

Abstract

Invasive species are believed to spread through a process of stratified dispersal consisting of short-distance diffusive spread around established foci and human mediated long-distance jumps. Brazilian peppertree (Schinus terebinthifolius), native to South America, was introduced twice as an ornamental plant into Florida, USA, just over 100 years ago. A previous study indicated that these two introductions were from genetically differentiated source populations in the native range. In this study, we took advantage of these contrasting genetic signatures to study the spatial spread of Brazilian peppertree across its entire range in Florida. A combination of spatial genetic and geostatistical analyses using chloroplast and nuclear microsatellite markers revealed evidence for both diffusive dispersal and long-distance jumps. Chloroplast DNA haplotype distributions and extensive bands of intra-specific hybridization revealed extensive dispersal by both introduced populations across the state. The strong genetic signature around the original introduction points, the presence of a general southeast to northwest genetic cline, and evidence for short-distance genetic spatial autocorrelation provided evidence of diffusive dispersal from an advancing front, probably by birds and small mammals. In the northernmost part of the range, there were patches having a high degree of ancestry from each introduction, suggesting long-distance jump dispersal, probably by the movement of humans. The evidence for extensive movement throughout the state suggests that Brazilian peppertree will be capable of rapidly recolonizing areas from which it has been eradicated. Concerted eradication efforts over large areas or the successful establishment of effective biocontrol agents over a wide area will be needed to suppress this species.

The role of intraspecific hybridization in the evolution of invasiveness: a case study of the ornamental pear tree Pyrus calleryana

“…In the tree species Schinus terebinthifolius for example, there is evidence of multiple introductions into North America from genetically different source populations along with post-introduction recombination events (Williams et al 2005(Williams et al , 2007. The same is also true for the grass Phalaris arundinacea (Lavergne and Molofsky 2004Molofsky , 2007, which at one time had been suggested to be dominated by European cultivars that escaped cultivation (see Lavoie and Dufresne 2005).…”

Intravarietal polymorphisms reveal possible common ancestor of native Schinus terebinthifolius Raddi populations in Brazil

“…However, we are far short of elucidating the course of these long distance dispersions or even explaining the evolutionary process that led to such ecoplasticity, although we recommend more detailed phylogeographic studies, and expansion of sample groups (Mandon-Dalger et al, 2004;Williams et al, 2007;Jesus and Monteiro Filho, 2007).…”

“…These results corroborate the hypothesis of stratified dispersion of the Brazilian peppertree; this may involve both local spread around already-established populations, and also long distance jumps. This combination of dispersions has considerably increased the distances of expansion, and is used as the basis for a hypothesis for understanding the rapid advance of tree species following the last glaciation (Petit et al, 2004;Williams et al, 2007).…”

New xenophytes from the Canary Islands (Gran Canaria and Tenerife; Spain)

“…In addition to those localities listed above, it was also seen in Playa Paraiso (El Pinque), Callao Salvaje (Playa Ajabo), Santa Cruz de Tenerife (barranco Tahodio), Las Caletillas, Guargacho, Puerto de la Cruz (Parque Taoro), etc. Birds that feed on the fruits of S. terebinthifolia seem to play an important role in the processes of naturalization of this species in the Canary Islands (see also Panetta and McKee 2006;Williams et al 2007;Mink et al 2015). A future wider naturalization and subsequent invasive behavior in the Canary Islands is predictable.…”