After centuries of colonization and trade, South Africa is now home to alien species from Australia, Europe, Asia, and the Americas. As an antidote, a pioneering program called Working for Water (WfW) has cleared about 1 million hectares of invasive species in the past 15 years.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/unleashing-army-repair-alien-ravaged-ecosystems
[2] http://admin.indiaenvironmentportal.org.in/category/author/robert-koenig
[3] http://admin.indiaenvironmentportal.org.in/category/journal/science
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/weeds
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/invasive-alien-species
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/south-africa
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ecosystems