TY - JOUR
T1 - Following in the footsteps of invasion
T2 - comparisons of founder and invasive genotypes of two independent invasions reveal site-specific demographic processes and no influence by landscape attributes on dispersal
AU - Castillo, María L.
AU - Schaffner, Urs
AU - Mbaabu, Purity R.
AU - Shiferaw, Hailu
AU - van Wilgen, Brian W.
AU - Eckert, Sandra
AU - Choge, Simon
AU - Münzbergová, Zuzana
AU - Le Roux, Johannes J.
N1 - Copyright the Author(s). Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
PY - 2024
Y1 - 2024
N2 - To understand the success of invasive alien species, it is necessary to evaluate the site-specific eco-evolutionary challenges they face in their new environments. We explored whether the rearrangement of genetic diversity is linked to the invasiveness of Prosopis juliflora by (i) comparing different stages of invasion (founding vs invasive populations) in two invaded areas (Afar Region, Ethiopia and Baringo County, Kenya) to evaluate whether different stages are dominated by different genetic attributes (e.g., characteristic genotypes or levels of genetic diversity) and by (ii) evaluating if landscape features affected dispersal between invasive populations in the two invaded areas. We hypothesised that different invasion stages would have unique genetic characteristics due to either site-specific demographic and/or dispersal dynamics. We also compared the genetic characteristics at an ‘invasive–non-invasive congener’ level by studying the non-invasive P. pallida, introduced to Baringo County, and assessed whether it hybridises with P. juliflora. In the Afar Region, the establishment and spread of P. juliflora were characterised by extensive gene flow that homogenised genetic diversity across all populations. In contrast, in Baringo County, invasive populations had lower genetic diversity than founders, and genetic differentiation was lower between invasive populations than between invasive and founder populations. In both invaded areas, we found no evidence that dispersal was hampered by geographic distance, bioclimatic conditions, or distance to roads, rivers and villages, at least at the spatial scales of our study; indicating frequent long-distance dispersal. Allelic richness was higher in P. juliflora than P. pallida founders and hybrids were mainly planted trees probably resulting from the sympatric cultivation of the two species following their introduction. Thus, management actions on Prosopis invasion in eastern Africa should consider site-specific dynamics occurring during the invasion.
AB - To understand the success of invasive alien species, it is necessary to evaluate the site-specific eco-evolutionary challenges they face in their new environments. We explored whether the rearrangement of genetic diversity is linked to the invasiveness of Prosopis juliflora by (i) comparing different stages of invasion (founding vs invasive populations) in two invaded areas (Afar Region, Ethiopia and Baringo County, Kenya) to evaluate whether different stages are dominated by different genetic attributes (e.g., characteristic genotypes or levels of genetic diversity) and by (ii) evaluating if landscape features affected dispersal between invasive populations in the two invaded areas. We hypothesised that different invasion stages would have unique genetic characteristics due to either site-specific demographic and/or dispersal dynamics. We also compared the genetic characteristics at an ‘invasive–non-invasive congener’ level by studying the non-invasive P. pallida, introduced to Baringo County, and assessed whether it hybridises with P. juliflora. In the Afar Region, the establishment and spread of P. juliflora were characterised by extensive gene flow that homogenised genetic diversity across all populations. In contrast, in Baringo County, invasive populations had lower genetic diversity than founders, and genetic differentiation was lower between invasive populations than between invasive and founder populations. In both invaded areas, we found no evidence that dispersal was hampered by geographic distance, bioclimatic conditions, or distance to roads, rivers and villages, at least at the spatial scales of our study; indicating frequent long-distance dispersal. Allelic richness was higher in P. juliflora than P. pallida founders and hybrids were mainly planted trees probably resulting from the sympatric cultivation of the two species following their introduction. Thus, management actions on Prosopis invasion in eastern Africa should consider site-specific dynamics occurring during the invasion.
KW - demographic stochasticity
KW - dispersal
KW - invasive spread
KW - microsatellites
KW - Prosopis
KW - woody invasive species
UR - http://www.scopus.com/inward/record.url?scp=85199521969&partnerID=8YFLogxK
U2 - 10.3897/NEOBIOTA.93.117457
DO - 10.3897/NEOBIOTA.93.117457
M3 - Article
AN - SCOPUS:85199521969
SN - 1619-0033
VL - 93
SP - 263
EP - 291
JO - NeoBiota
JF - NeoBiota
ER -