The White Horse Press Full citation: Johnson, Sarah, ed. Bioinvaders. Themes in Environmental History series. Cambridge: The White Horse Press, 2010. http://www.environmentandsociety.org/node/2811. Rights: All rights reserved. © The White Horse Press 2010. Except for the quotation of short passages for the purpose of criticism or review, no part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical or other means, including photocopying or recording, or in any information storage or retrieval system, without permission from the publishers. For further information please see http://www.whpress.co.uk. Bioinvaders Copyright © The White Horse Press 2010 First published 2010 by The White Horse Press, 10 High Street, Knapwell, Cambridge, CB23 4NR, UK Set in 10 point Times All rights reserved. Except for the quotation of short passages for the purpose of criticism or review, no part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical or other means, in- cluding photocopying or recording, or in any information storage or retrieval system, without permission from the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 978-1-874267-55-3 (PB) Contents Publisher’s Introduction Sarah Johnson iv Strangers in a Strange Land: The Problem of Exotic Species Mark Woods and Paul Veatch Moriarty 1 Nativism and Nature: Rethinking Biological Invasion Jonah H. Peretti 28 Exotic Species, Naturalisation, and Biological Nativism Ned Hettinger 37 Plant Transfers in Historical Perspective William Beinart and Karen Middleton 68 Weeds, People and Contested Places Neil Clayton 94 Re-writing the History of Australian Tropical Rainforests: ‘Alien Invasives’ or ‘Ancient Indigenes’? Rachel Sanderson 124 Prehistory of Southern African Forestry: From Vegetable Garden to Tree Plantation Kate B. Showers 144 Rhododendron ponticum in Britain and Ireland: Social, Economic and Ecological Factors in its Successful Invasion Katharina Dehnen-Schmutz and Mark Williamson 171 Fighting With a Weed: Water Hyacinth and the State in Colonial Bengal, c. 1910–1947 Iftekhar Iqbal 197 ‘An Enemy of the Rabbit’: The Social Context of Acclimatisation of an Immigrant Killer Philippa K. Wells 221 Motives for Introducing Species: Palestine’s Carp as a Case Study Dan Tamir 248 Publisher’s Introduction Sarah Johnson KNoWING THE ENEMy: PRoBLEMS oF DEFINITIoN In a globalised and cosmopolitan world, the mobility of human beings, culture and commodities across continents is taken for granted, and it is a liberal orthodoxy that the resulting ‘multiculturalism’ is desirable. Similar movements in the biosphere, however, are highly contentious. Discourse about ‘alien’ species such as mink in Scotland and kudzu in the Southern United States often bespeaks fear and loathing. The present volume seeks to define and explore what is meant by the categories ‘exotic’, ‘alien’ (and the corollary ‘native’), and ‘invasive’, suggesting that while there are clear-cut exempla of the ‘nefarious’ (Peretti, p. 28) and broad agreement that ill-managed introductions are dangerous, both history and philosophical thought raise as many questions as they resolve about the nature and status of such species. The volume opens with three essays – by Woods and Moriarty, Peretti and Hettinger – that problematise the easy categorisation of species and re- sist ‘catch-all’ definitions and solutions. Woods and Moriarty (p. 2) present Noss and Cooperrider’s 1994 definition of an exotic as ‘the result of direct or indirect, deliberate or accidental introduction of the species by humans’ which has ‘permitted the species to cross a natural barrier to dispersal’, but question and complicate the assumptions that such attempts at single-sentence analysis entail. They offer a list of ‘exotic’ and ‘native’ qualities, illustrat- ing the general consensus of views about alien species: they are human- introduced, whether directly or indirectly, intentionally or unintentionally; they exist outside their historical or natural range; they tend to ‘damage or degrade the local ecosystem, displacing or eliminating native species’; and they are not integrated with the ‘ecological community’ (pp. 11–12). Natives, on the other hand, are characterised, broadly, by belonging and benignity. Woods and Moriarty’s definitions function as ‘cluster concepts: a given ‘exotic’ or ‘native’ species will not possess all these characteristics but it is likely to exhibit some of them, and thus the distinction between natives and exotics admits of degrees. They propose that an invasive species will almost always be non-native, while a non-native species might not be invasive. This distinction is collapsed in Hettinger’s ‘precising definition of exotics as any species significantly foreign to an ecological assemblage, whether vi Introduction or not the species causes damage, is human introduced, or arrives from some other geographical location’ (p.38). Hettinger observes that, ‘Unless one accepts an idyllic conception of perfectly-harmonious natural systems, one must admit that native species can wreak havoc in their native ranges’ (p.40). Beinart and Middleton, in a paper that deals specifically with plant transfers but illuminates the wider problem of definition, raise questions that reverberate through the essays in this volume: Is it possible to make a useful distinction between human agency in plant transfers, and other forms of plant spread? When does an intentional and apparently controlled transfer become an invasion? What is the borderline between useful plants and those seen as weeds? (p.69) So, ‘invasiveness’ is established as a fuzzy concept, its vagueness compounded by anomalies: for example, there exist certain North American tamarisks, descended from human introductions, but now evolved into a new species, present nowhere else in the world; it would seem bizarre to assert that these are not in some sense native. As Woods and Moriarty observe, addressing the subject of ‘bio-invaders’ opens ‘a Pandora’s box of conceptual and nor- mative quandaries’ (p.1) over the ideas of ‘native’, ‘alien’, ‘invasiveness’ and even ‘species’. These quandaries permeate the present volume. Several authors offer examples of clearly ‘nefarious’ species, including the brown tree snakes that have decimated bird populations on Guam (cited by both Peretti and Woods and Moriarty) and the water hyacinth that has choked the canals of Bangladesh, as described by Iqbal. Such introductions, made thoughtlessly or on an aesthetic or socio-economic whim, have had catastrophic effects on native ecosystems, in the latter case ‘choking up the natural arteries of trade, impeding agricultural operations and menacing the health of the people’ (Iqbal, p.198). However, even undeniably destructive introduced species have their advocates – Hettinger notes that there are those who consider the Japanese kudzu vines that drape southern telegraph poles to be attrac- tive camouflage, though they are fearsome stranglers of native trees; and Williams and Dehnen Schmutz relate anecdotally that, while conservation biologists unite in condemning naturalised Rhododendron ponticum, local communities vociferously defend the shrubs’ aesthetic value. Even species that are accepted as ‘invasive’ are able to win hearts and minds. Species rarely sit obediently in a single category and, as many of the authors represented here discuss, ‘cultural definition allows the same plant to change status in the context of historically dynamic socio-ecological sys- tems’ (Beinart and Middleton, p.82, outlining different attitudes to Opuntia (prickly pear) in southern Africa and Madagascar). Clayton engages with Introduction vii similar questions in his study of weeds – both as a concept and in the specific context of New Zealand agriculture. From prehistory, the loaded categories of ‘weed’ and ‘useful plant’ (Beinart and Middleton, p.69) have structured human responses to flora, but, despite attempts to taxonomise ‘weediness’, these surely say more about society at a given point in time or space than innate qualities of the plants. Beinart and Middleton address this in their decision to ‘include cultivated crops, garden plants, weeds and plant invad- ers within the same frame of analysis because many plants […] fit uneasily into any one of these categories’ (p.88). Much of world agriculture relies on ‘exotic’ species, introductions from elsewhere that we are accustomed to regard as beneficial and would certainly not consider exterminating – wheat in North America, potatoes in Europe, chillies in India and corn in Africa – introductions that have been compre- hensively assimilated into each culture’s definition of itself. As Beinart and Middleton argue, ‘most agricultural development has been dependent on plant transfers’ (p.68) and their chapter traces the literature concerning networks of formal (by means of agriculture, forestry, trade and botanical collecting) and informal plant transfers. Showers pursues the case of forestry further, noting in South Africa an irony of the sort that recurs frequently in the study of species introductions: as well as fuelling ‘the growing demand for wood products: supports for mines, fuel for steamdriven machinery, timber for railroad construction, and bark for tanning’ (p.152), nineteenth century scientists had an improving vision that silviculture of alien species in South Africa would eventually allow the