Lantana camara L. (sensu lato) has a wide range of impacts throughout its global invasive range. Here we review the mechanisms driving its invasion dynamics in South Africa at national (biome, habitat) and regional (within a protected area) scales. Although only three introduction events into South Africa have been recorded (the earliest in 1858), as of 1998 L. camara was found in over 2millionha (total area), with a condensed area of about 70,000ha. Moreover, L. camara is present in most of the country's major biomes and a diversity of habitats, confirming its broad ecological tolerance. Using correlative bioclimatic models, we show that under future climate conditions, L. camara's range in South Africa could expand considerably over the coming decades. While human-mediated dispersal and climatic suitability have been crucial in shaping L. camara's current broad-scale distribution in South Africa, dispersal by birds and along rivers are important drivers of invasion at landscape scales. For example, current evidence suggests that in the Kruger National Park, L. camara has spread primarily along rivers. We conclude with a discussion on the implications of the different invasion dynamics for biological control and management, and provide recommendations for future research

Aim  The genetic makeup and evolutionary potential of alien species can be profoundly influenced by their introduction history, but without detailed historical records, it can be difficult to ascertain the strength of this historical contingency. We explore how the known introduction histories combined with phylogeographic patterns in the native range have affected the genetic diversity in the invasive range for five Australian trees introduced to South Africa (Acacia cyclops, Acacia mearnsii, Acacia pycnantha, Acacia saligna and Paraserianthes lophantha).Location  Western Australia, South Australia, Victoria and New South Wales (native and invasive ranges), and South Africa and the Hawaiian Islands (invasive range).Methods  DNA sequence data were generated for all study species for either the external transcribed spacer (ETS) or plastid rpl32‐trnL^(UAG) gene regions (combined total of 180 DNA sequences). Using statistical parsimony networks and genetic diversity indices, we compared genetic structure and variation in native and invasive ranges.Results  Australian acacia species tend to have high genetic diversity at the population level in their native ranges, often showing high intra‐specific divergence. In most instances, these species have similar levels of population genetic diversity in their adventive ranges in South Africa, but lack structure. For A. cyclops, A. saligna and P. lophantha, we found evidence for intra‐specific hybridization between mixed genetic entities in the invasive range, arguably as a result of the structured native range being broadly sampled prior to introduction.Main conclusions  Invasive species that have been extensively used in forestry often have complex introduction histories resulting in equally complex genetic signatures in the invasive range. Our results show that extreme caution should be taken when using indirect inferences (molecular genetic data) of introduction histories in the absence of detailed introduction records.

Aim  To explore whether the subspecific genetic entities of Acacia saligna occupy different bioclimatic niches in their native and introduced ranges and whether these niches are predictable using species distribution models (SDMs).Location  Australia, South Africa and the Mediterranean Basin.Methods  Species distribution models were developed in MAXENT using six climatic variables to calculate the climatic suitability of the ranges of A. saligna. We assessed (1) the subspecific niche differences identified by SDMs using measures of niche overlap and model performance; (2) the ability of SDMs to predict the most likely subspecific genetic entities present in South Africa based on comparisons to genetic data; and (3) the ability of SDMs to predict the most likely subspecific genetic entities present in the Mediterranean Basin. All model projections were assessed for sensitivity and modelled prevalence as indicators of model fit and predictability.Results  The SDMs identified different subspecific bioclimatic niches in the native range. Sensitivity and modelled prevalence show that none of the models correctly predicted the full range of A. saligna in South Africa or the Mediterranean Basin. Models also show that the South African niche is different to that in the native range.Main conclusions  Subspecies of A. saligna occupy quantifiably distinct bioclimatic niches in their native ranges, implying that they should occupy distinct niches in their invasive ranges. However, projections to the introduced range did not correspond with known occurrences. Our SDMs are unable to predict the full introduced niche of A. saligna at a species or subspecies level in either South Africa or the Mediterranean Basin. Range limits in the native and introduced ranges may be determined by additional factors not used in the SDMs developed in this study.