Current and future invasion potential of Senna didymobotrya under the
changing climate in Africa
Abstract
Climate change is thought to facilitate the introduction and spread of
invasive alien species. The present study aimed at examining the present
and future invasive potential of S. didymobotrya under the changing
climatic conditions using the Species Distribution Model. Two
representative concentration pathways (RCP4.5, and RCP8.5), and seven
bioclimatic including one topographic variable were used to simulate the
current and future (2050s and 2070s) distribution of S. didymobotrya
invasion in Africa. The model performance evaluation is done based on,
the area under the receiver operating characteristic curve (AUC) and
true skills statistics (TSS). The results of the study showed that under
current climatic conditions 18% of the continent of Africa is suitable
for S. didymobotrya establishment and invasion. Eastern Africa is seen
as the most suitable habitats for S. didymobotrya invasion followed by
southern Africa. The predicted model shows that in the 2050s under
RCP4.5 and RCP8.5, 3.4% and 3.17% of the continent will be highly
suitable for S. didymobotrya invasion, respectively. In the 2070s, the
highly suitable area for the species is predicted to be 3.18 % and
2.73% in RCP4.5 and RCP8.5, respectively. The low to moderate
suitability under RCP 4.5 and RCP8.5 in the 2050s is projected as 17.4
% and 20.5 % and this area is increased in the 2070s to19.11% and
22.82 for the RCP 4.5 and RCP 8.5, respectively. The results of this
study indicate a significant increase in the vulnerability of habitat
for S. didymobotrya invasion under the future climatic conditions. Our
current finding suggests the future biodiversity conservation strategy
and policy direction should focus on the means and strategy of limiting
the rate of expansion of invasion and distribution.