From the author of the acclaimed books on climate change, Scorched and Boiling Point, comes a new look at our environment – this time from the ground up: Leonie Joubert’s Invaded: the biological invasion of South Africa. Kader Asmal – former minister of Water Affairs and Forestry – joined Joubert at the book’s launch at Exclusive Books Hyde Park earlier this week.

Invaded tells the story of invasive alien plant and animal species in South Africa: Joubert describes the journey of these species as the real story of global travel. Ever since the evolution of modern human beings about 150 000 years ago, and our first journeys out of Africa, we have taken plants and living creatures with us.

Along with alien plants, of course, comes the spectre of challenges to water resources: invasive plants use more than 7% of South Africa’s water, which is water-scarce to begin with.

Speaking before introducing Joubert, Asmal – who was instrumental in setting up the Working for Water project and drafting the National Water Act of 1998, having been inspired by the work of Dr Guy Preston – praised Invaded and said he was pleased to write the foreword to such a “remarkable and beautifully constructed book”. He found Joubert has a “way with words” which results in scientific work that’s passionately communicated – and he hoped Joubert’s book would be widely read.

Using the launch platform, Professor Asmal appealed directly to Trevor Manuel, the new Minister of Planning, to launch an enquiry into the status of water in South Africa, that the nature and quality of SA’s water resources be properly evaluated.

Joubert spoke about the familiar troublesome plants in SA such as the wattle, pine, gums and hakea, and explained how Invaded introduces a few more “culprits”: the Mediterranean mussel and the Japanese oyster, for instance. The book explores the history of these invasive species – how the mussel probably arrived as a stowaway on the bellies of a ships ,and how the oyster may have been taken from the aquaculture beds of Knysna by tourists.

She elaborated on how the spread of alien plant species can influence other species and ecosystems. Compelling and curious are eerie tales such as how the triffid weed could be turning the crocodiles of St Lucia into females and the plague of cats and mice on Marion Island.

Today’s challenge comprises not just the fact that plants travel around the globe, but the speed with which they now move. The problem is that invasive species change the way ecosystems work. She likened them to an oil spill – something that cannot be 100% cleared up.

However Invaded is, for her, a book of hope – because it identifies what we’re up against, which in turn enables us to start fixing the problem. The human ape that rose up and started walking out of Africa 150 000 years aog made the mess, and so surely we now can and must get ourselves out of it!

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