The potential range of Ailanthus altissima (tree of heaven) in South Africa: the roles of climate, land use and disturbance
Format Extent1235663 bytes
MetadataShow full item record
Invasive trees are a major problem in South Africa. Many species are well established whereas others are still in the early stages of invasion. The management of invasive species is most cost effective at the early stages of invasion; it is thus essential to target and contain naturalizing invaders before they spread across the landscape. Multi-scale species distribution models (SDMs) provide useful insights to managers; they combine species-occurrence observations with climatic variables to predict potential distributions of alien species. Applying SDMs in human-dominated ecosystems is complicated because many factors associated with human actions interact in complex ways with climatic and edaphic factors to determine the potential suitability of sites for species. The aim of this study was to determine the degree to which a worldwide invader, A. altissima (Simaroubaceae) has occupied its potential range in South Africa, to identify areas at risk of future invasion. To do this we built a set of SDMs at both global and country scales using climatic, land use and human-footprint data. Climatic data best explained the distribution of A. altissima at the global scale whereas variables reflecting human-mediated disturbances were most influential at the national scale. Our analyses show the importance of human-mediated disturbances at a global scale and human occupancy at a country scale in determining the range limits of A. altissima. Populations of this tree species are already present in most parts of South Africa that are environmentally suitable for the species, and management actions need to focus on preventing increases in density in these areas.
Showing items related by title, author, creator and subject.
Richardson, DM (BLACKWELL PUBLISHING LTD, 2004-11-01)This issue of Diversity and Distributions carries papers on a wide range of topics dealing with invasions of introduced plant species. The collection of articles did not arise from a conference or workshop, but grew from ...
Richardson, DM; Pysek, P (HODDER ARNOLD, 2006-04)This paper considers key issues in plant invasion ecology, where findings published since 1990 have significantly improved our understanding of many aspects of invasions. The review focuses on vascular plants invading ...
Richardson, DM (CZECH BOTANICAL SOC, 2006-11)The global-scale natural experiment created by the widespread dissemination of most of the I I I species of pines (genus Pinus, family Pinaceae) has shed light on many aspects of plant invasion ecology. Introductions and ...