Invasive Species

+557' 81.

:HHGVDV)XUQLWXUH_0DULQH,QYDVLYHV_0RQNH\)RONORUH_$QLPDO(PRWLRQV 6SHFLDO,QYDVLYH6SHFLHV

EWTTGPVEQPUGTXCVKQP^ 6JKUOCIC\KPGKURTQFWEGFYKVJUWRRQTVHTQO

%WTTGPV%QPUGTXCVKQPECTTKGUVJGNCVGUVKPTGUGCTEJPGYUHTQOPCVWTCNCPFUQEKCN UEKGPEGHCEGVUQHEQPUGTXCVKQPUWEJCUEQPUGTXCVKQPDKQNQI[GPXKTQPOGPVCNJKUVQT[ CPVJTQRQNQI[UQEKQNQI[GEQNQIKECNGEQPQOKEUCPFNCPFUECRGGEQNQI[

(QTOQTGFGVCKNUXKUKVQWTYGDUKVGCVYYYEWTTGPVEQPUGTXCVKQPQTI EQPVGPVU^%WTTGPV%QPUGTXCVKQP 5RGEKCN+PXCUKXG5RGEKGU

5RGEKCN)WGUV'FKVQTKCN /CMKPI%JCKTUHQT%QPUGTXCVKQP Introducing Invasives Ankila Hiremath & Vikram Dayal Some say putting a weed to good use is the best way to control it. Can this novel strategy result in a win-win for multiple-interest groups? 2GTURGEVKXG R Uma Shaanker, Gladwin Joseph, NA Aravind, R Kannan & KN Ganeshiah How Lantana Invaded India Gyan P Sharma, AS Raghubhanshi Invading the Andamans 4GUQNWVKQPVQ4GUVQTG Rauf Ali No half measures work in eradicating persistent invaders. Complete eradication with local participation is the only long-term solution. 5RQVNKIJV Suresh Babu, Amit Love & Cherukuri Raghavendra Babu Tackling Invasive Species: #e Story of a Shrub in South Africa Charlie Shackleton, James Gambiza 6JG'EQPQOKEUQH+PXCUKXGU Anatomy of an Invader John Volin If we take the expenditure to counter pests in agriculture, forestry and !sheries along with the output lost through invasive pests and pathogens in all sectors, and add to that the costs of both, emergent and recurrent diseases of international ori- %QPUGTXCVKQP0GYUHGGF gin, the problem of invasive species makes all other environmental problems pale into insigni!cance. 5PKRRGVU Charles Perrings, Harold Mooney & Mark Williamson 4GUGCTEJKP6TCPUNCVKQP Culture & Conservation %QTCNUQT%QNCDGVYGGPVJG&GXKNVJG&GGR$NWG5GC Joining the Dots Lessons from History An introduced seaweed that brings income to farmers but death to reefs leaves us Removing Rats with Care con"icted. To harvest or eradicate? Kalyani Ganapathy Naveen Namboothri & Kartik Shanker $QQMHTQOVJG#VVKE

#e #inking and Feeling Animal Sartaj S Ghuman GFKVQTŏUPQVG^ Invasive species are a part of our lives, so much so that we don’t even notice that a number of the plants and animals around us are foreigners. More importantly, their impact on native biodiversity goes unnoticed. In this issue, we have contributions from distinguished scholars working on a diverse assemblage of invasive species, and within these pages you will !nd some unlikely invaders—elephants in the Andamans, mosquitoes in Hawaii, and domestic cats everywhere.

Over the past three years Current Conservation has been a source of research news and conservation stories, but from this volume onwards we are bringing about a change in our pro!le to include a broader variety of material, a new look, and a revamped website to engage those of you interested in conservation, science or simply just nature.

For instance, are books ever too old to be read? We introduce a new book review Cover art by Kalyani Ganapathy section—‘Book from the Attic’, where we solicit reviews of dated, but nonetheless pivotal, books that have changed the way we view the natural world around us. And what better book to inaugurate this section than one of Darwin’s? Page 36 reviews Darwin and his thoughts on animal emotions.

As Current Conservation transforms into this new avatar, we solicit your participation, feedback and any input you may care to give us. We look forward to hearing from you.

'FKVQT #FXKUQT[$QCTF %QR[TKIJV

R Nandini Rohan Arthur, India All articles in Current Conservation, unless Bram Buscher, #e Netherlands otherwise noted, are licensed under a Creative Commons Attribution 3 License. /CPCIKPI'FKVQT Brian Child, USA You are free to copy, distribute and transmit the Hetal Hariya Vikram Dayal, India work, and to remix or adapt the work under the Jose Alexandre Diniz-Filho, Brazil following conditions: 5GPKQT'FKVQTU Brendan Godley, UK * You must attribute the work in the manner Kartik Shanker Ferenc Jordan, Hungary speci!ed by the author or licensor (but not in any way that suggests that they endorse you or Ankila Hiremath John Mathew, USA your use of the work). Harini Nagendra, India * For any reuse or distribution, you must make &GUKIP6GCO Fred Nelson, Tanzania clear to others the license terms of this work. Pallavi Baasri Wallace J Nichols, USA * Any of the above conditions can be waived if you get permission from the copyright holder. Arjun Shankar Meera Anna Oommen, India * Nothing in this license impairs or restricts the Kalyani Ganapathy Samraat Pawar, USA author’s moral rights. Suhel Quader, India Javier Arce-Nazario, USA #e full text of this license is available at: http://creativecommons.org/licenses/by/3.0/ Madhu Rao, Singapore Ana Rodrigues, UK Jane Southworth, USA

^EWTTGPVEQPUGTXCVKQP EQPUGTXCVKQPPGYUHGGF^5QWVJ#UKC

young, and the subspecies of swiftlet on the Andaman Islands is under threat. E$orts to control this by including the species in Schedule I of the Indian Wildlife Protection Act (according it the highest degree of protection) failed, given the di%culty of monitoring caves in inhospitable terrain. #e solution could lie in a unique program initiated by the late Ravi Sankaran and now ex- Photo: Kalyan Varma | Artwork: Pallavi Baasri ecuted by Shirish Manchi, Salim Ali Centre for Ornithology and Natural 5('/,*+7$5($635(9(17&/26((1&2817(56 History, Coimbatore in association with the Andamans Forest Department. #e program employs poachers to protect A novel warning system to alert villa- umented elephant-human con"ict in caves (numbering 181), and nests are gers to passing elephants could reduce Valparai since 2002, hope to build on harvested after the !rst breeding cycle. human-elephant con"ict on the Valpa- the success of earlier initiatives. #e rai plateau in Tamil Nadu, southern team previously introduced a system Additionally, birds are translocated to India, a mosaic of plantations (predo- that allows villagers to learn of eleph- abandoned buildings in order to estab- minantly tea), woodlots and rainforest ant herd movement across the plateau lish breeding centres similar to those fragments. through cable TV. #e movements of in Southeast Asia. Cross-fostering of the elephant herds appeared on a news chicks from caves to the buildings will Home to one of the largest populations ticker across the screen of a local tele- eventually encourage more birds to of elephants in the region, the plateau vision channel through the evenings. breed in the buildings, given that the sees frequent interactions between peo- species is philopatric. Nests are kept in ple and elephants that result in acciden- Technology o$ers promising solutions the custody of the forest department, tal human fatalities, usually late in the to conservation problems, says Kumar. and their sale will be monitored by a evening or at nighttime, when elephant co-operative society (comprising of movement is hard to see. forest department, local communities 6HOOLQJ1HVWVWR6DYH%LUGV and biologists). #e team persuaded the But a new initiative by M Ananda Indian Government to deregister the Kumar and colleagues at the Nature #e indiscriminate poaching of swiftlet species from Schedule I on a probation Conservation Foundation, Mysore, nests could be ended while at the same basis for 3 years, during which this con- could change all that. In association time allowing simultaneous sustainable troversial program will be monitored. with the corporations, running the harvest of nests in the Andaman Isla- plantations, the Forest Department, nds, India, according to a bold initiative media, and women’s self-help groups, by scientists and forest o%cers. Kumar and his team plan to install "ashing red lights activated by GSM Edible-nest swiftlets are widely distri- based technology mounted on poles buted across south and southeast Asia, near colonies and bus stops. #ese and their nests are the main ingredient

)DVW)DFWV Shirish Manchi ‘Elephant Alert Indicators,’ seen from in bird-nests soup, a popular dish in the * Nests in caves in groups up to a kilometer away, will "ash red Orient region. Valued at US$ 400/kg * Build nest out of saliva when elephants are in the vicinity, al- in the international market, poachers * Build nest for every brood lowing locals to use alternative routes in India can earn up to Rs. 10,000/kg * Nest philopatry (return to breed or wait till the lights are turned o$. of nests harvested. Poaching of nests in the cave they were born in) Kumar and his team, who have doc- from caves prevents birds from raising

EWTTGPVEQPUGTXCVKQP^ URGEKCN^+PXCUKXG5RGEKGU

%LRORJLFDO,QYDVLRQV IURPHFRORJ\WRKXPDQZHOOEHLQJ

People have moved species from one part of the globe to another throughout human history. For the most part species introductions have been deliberate—most of the food we eat, the !bres we use, the plants in our gardens, have their origins in distant parts of the world. Occasionally, species introductions have been inadvertent or acc- idental—as hitchhikers on deliberate introductions, or, increasingly, as a collateral to growing global travel and trade. Every so often, an introduced species tends to become dominant in its de novo environ- 'XGT[UQQHVGPCPKPVTQFW ment, competing with native species, alter- EGFURGEKGUVGPFUVQDGEQOG ing the structure and functioning of native FQOKPCPVKPKVUFGPQXQGPX ecosystems, and doing untold ecological KTQPOGPVEQORGVKPIYKVJ and economic damage: the arrival of avian

Kalyani Ganapathy PCVKXGURGEKGUCNVGTKPIVJG malaria in the Hawaiian islands led to the UVTWEVWTGCPFHWPEVKQPKPI extinction of several bird species unique to QHPCVKXGGEQU[UVGOUCPF the archipelago, and to the decline of many others; introduced grasses have altered !re FQKPIWPVQNFGEQNQIKECNCPF regimes, thereby changing ecosystem stru- GEQPQOKEFCOCIG cture, composition, and dynamics in the Americas; introduced trees are reducing water "ow into aquifers and a$ecting water supply to Cape Town in South Africa. #- ese are examples of what have come to be known as invasive alien species, ‘invasive’ a reference to the ecological damage they cause, and ‘alien’ a reference to their non- native biogeographical provenance. So great is the concern about invasive alien species today, that the international Con- vention on Biological Diversity has ranked them amongst the foremost threats to biodiversity and ecosystem functioning.

A British biologist, Charles Elton, was amongst the earliest to draw attention to

^EWTTGPVEQPUGTXCVKQP the problem of invasive species in the microorganisms in their de!nition of both Shaanker et al. and by Shackleton late 1950s. He was concerned that with biological invasive species, thus enco- and Gambiza. Shaanker et al. argue increasing human-aided movement of mpassing issues of emergent and recur- that once an invasive species has bec- species around the planet, the unique- rent human diseases. #eir assertion, ome widespread it may be best to live ness and distinctness of biodiversity that the problem of invasive species is with it and enable local communities in di$erent parts of the world was in the most signi!cant environmental to draw a livelihood from it, thus red- danger of being homogenised. He cau- issue facing humanity, is therefore not ucing the costs of control. Shackleton tioned that though not all alien species surprising. and Gambiza draw our attention to were necessarily invasive, those that Euryops !oribundus, a native invasive were could have devastating impacts. Volin reviews work on Lygodium micro- species in South Africa; its eradication, He also cautioned that the potential phyllum, a climbing fern native to the though of bene!t to livestock owners, danger from invasive alien species was Old World and now widespread in the would adversely a$ect women who likely to be greatest on oceanic islands, southeastern USA. #is article illustr- depend on it for fuel. with their unique but vulnerable biota, ates the kinds of information, across and in disturbed environments, where scales, required to understand the ecol- Rauf Ali is dismissive of the focus on available resources could be readily ogical underpinnings of a species’ inva- what he terms the ‘page 3 species,’ incl- preempted by invasive species. siveness; such information can aid the uding lantana. Instead, he draws atten- search for appropriate control methods tion to the vulnerability of island eco- Today there is a great deal of interest, and enable predictive modeling of the systems, in this case the Andaman isl- both in what makes certain species species’ spread, of value for managers ands, to invasions. His choice of inva- more invasive than others, and in what and policy makers. sive species—both elephants and chital makes certain ecosystems more vulne- are native to the Indian mainland— rable to invasion than others—quest- #ree of the articles focus on Lantana helps underscore an important point, ions that can provide insights into how camara in India, undoubtedly a re"ec- that ‘alien’ is a biogeographical rather ecosystems are assembled. #ese question of lantana’s status as amongst Ind- than a political concept. His choice of tions also have tremendous practical ia’s most widespread terrestrial invasive invasive species also underscores the signi!cance for the conservation of bi- species. However, they examine very cultural obstacles to our dealing with odiversity and the services that society di$erent aspects of lantana—Sharma animal invasive species. derives from ecosystems, as they can and Raghubanshi focus on its ecolog- provide us with tools to predict which ical impacts, Babu et al. talk about Namboothri and Shanker draw our species are most likely to become inva- mitigation and control, and Shaanker attention to Kappaphycus alvarezii, sive, and can enable us to model invasi- et al. propose adaptation and related a marine invasive species, and its relat- ve species spread and to prioritise livelihoods. #e article by Sharma and ionship with industrial production of management interventions. #ere is Raghubanshi draws on their work on soft drinks. Cola production has cre- also growing interest in evaluating the the impacts of lantana on biodiversity ated an economic interest in the species, economic consequences of invasive and ecosystem functioning. #ey also to the extent that arguments are made species for human well being, and in propose that lantana’s invasive success contesting the species’ invasiveness. developing appropriate policies and ca- may not be explained by any one char- Who bears the burden of proof? pacities for invasive species prevention, acteristic of the species but rather, co- Should we adopt the precautionary control, or mitigation. uld be attributed to multiple mechan- principle? #is collection of summaries isms. Babu et al. describe a method they informs us that there are a great di- #is special feature brings together a have designed to control lantana and versity of biologically invasive species collection of articles that showcases a restore native species and ecosystem and contexts, with some fundamental diversity of concerns related to invasive functioning, which may have high ben- uncertainties but possibly great impli- alien species. Perrings et al. examine e!ts, particularly in protected areas. cations for human welfare. the economic and policy aspects of the problem of biological invasions at #e management of invasive species * Ankila Hiremath is a Fellow at ATREE, New Delhi, India. Mail at [email protected] a global scale, especially with respect can have complex e$ects on liveli- * Vikram Dayal is an Associate Professor at the to global trade. #e authors include hoods and ecology, as illustrated by Institute of Economic Growth, Delhi, India.

EWTTGPVEQPUGTXCVKQP^ HGCVWTG^47OC5JCCPMGT)NCFYKP,QUGRJ 0##TCXKPF4-CPCP-0)CPGUJCKCJ

6RPHVD\SXWWLQJDZHHGWRJRRGXVHLVWKHEHVWZD\WR FRQWUROLW&DQWKLVQRYHOVWUDWHJ\UHVXOWLQDZLQZLQIRU PXOWLSOHLQWHUHVWJURXSV"

#e management of invasives has focussed on preventing and containing invasive species and thereby mitigating their impacts on local biodiversity, ecosystem functioning, and human health. However, apart from a few examples, such management has been only partly successful while being very costly. #e management of invasive species is especially challenging in tropical human-dominated landscapes. Invasive species can exacerbate the biodiversity crisis by reducing population den- sities of native species, many of which are important for livelihoods of the rural poor. Invasive species could potentially lead to further marginalisation of these impoverished people. But the reverse is also true. In tropical human-dominated landscapes invasive species are often viewed as resources that can provide potential Ramesh Kannan economic bene!ts to the poor. Control of invasive species in these habitats may lead to loss of rural livelihoods. In low income countries, because people might Women artisans at work at the Lantana Craft Centre, Ramagalli, MM Hills exploit invasive species for food, !ber and fuel, there could be an ambivalent atti- tude to the control of invasive species. In these countries, invasive species control may have to be weighed against the resulting loss. #is challenges conventional wisdom about managing invasive species, at least for tropical landscapes. #is also creates an interesting dilemma: to control or not to control. Mainstream research on management of invasive species has scarcely addressed this question.

Management decisions do not conform to a ‘one size !ts all’, and a suite of di$- erent strategies-including exploitation of the invasive at some stage of its invasion -rather than a single strategy, could be regarded as an approach to minimizing the net costs. Optimising management strategies for invasive species requires evaluating the full range of costs and bene!ts of alternative control options. #e following questions can be considered: a) what are the threshold levels of invasion that warrant management (when bene!ts due to investments in control exceed the damage costs) and, as a corollary, b) at what threshold (or when), should management e$- ort be considered to have failed (i.e., when are bene!ts due to control actually less than the damage costs)?

^EWTTGPVEQPUGTXCVKQP Management of invasive species in the third phase may be Kalyani Ganapathy

We expect the ecological impact of an invasive species to be regarded as futile. But should management options to low at an early stage soon after introduction but before it has control invasive species at this stage be abandoned? Could spread widely (the ‘lag phase’). #e impacts of the invasive alternate management strategies be developed? species are likely to increase during the subsequent expone- ntial growth (‘logistic’) and stabilisation (‘equilibrium’) phases From a management perspective, the increasing ecologi- (see !gure). In the early stages of invasion, eradication is gen- cal cost of invasive species should be weighed against any erally preferred, both because the marginal costs are low and bene!ts that may accrue. In the range of options available because the potential bene!ts are large. Ironically, often no for management, one can allow for the entire spectrum management e$ort is initiated at this stage, either because the from complete eradication to adaptive management ecological costs are small or because they are not yet perceived. (wherein the species can actually be gainfully used; http: As both the abundance and the impacts of the invasion incr- //tncweeds.ucdavis.htm). Today, a number of species are ease, management investments start being made. Most man- notorious for being invasive across the world, and notable agement, though expensive, tends to be deployed during this among them are Eichhornia, Prosopis, and Opuntia. Con- phase. In the last, stable phase, management interventions are trol tor management of these invasive species, especially in not only very expensive but tend also to be the least successful. tropical human-dominated landscapes, with traditionally

EWTTGPVEQPUGTXCVKQP^

Lantana toys and furniture at the Krishi Mela 2010, University of Agricultural Sciences, Bangalore poor economies, has been nearly absent or woefully unsuc- communities in India depend almost exclusively on forest cessful. Over time, though, at least some of these invasive resources for their livelihood. On such community, the species have blended into the local ecosystems and become Soligas, were hereditarily dependent on bamboo and cane integrated into the livelihoods of people for two reasons. resources. In recent years indiscriminate extraction has severely depleted the natural stocks of cane and bamboo, First, invasive species tend to be abundant and freely available and has directly threatened their principal source of liveli- for harvest. Second, invasive species can o$er a suitable, if not hood. An appropriate substitute for the declining wild bam- a perfect, substitute for existing resources that are scarce or exp- boo and rattan resources could make a substantial di$er- ensive. Abundance and substitutability result in low opportu- ence to the Soligas. nity cost of collection and utilisation. We explored the possibility of using the locally abundant +H[QWECPPQVDTGCMKVCVNGCUVDGPFKV invasive species, lantana, as a substitute for bamboo and #e invasion and current spread of lantana across the world canes to maintain or even enhance the livelihoods of these represents a typical case of a successful invasive species. Man- communities, while alleviating the stress on beleaguered agement options for lantana are few, expensive, and possibly populations of bamboo and canes. Kannan and colleagues futile. One potential management strategy, therefore, would promoted the use of lantana as a substitute for bamboo be the utilisation of lantana. Could this lead to adaptive man- and canes and designed appropriate lantana products for agement of lantana in a manner that would reduce the net rural and urban markets. Over 350 men and women were cost of the species by partially o$setting both control and trained in the use of lantana at several !eld sites in South damage costs? We present a case study of a recent initiative India. More than 50 di$erent products, from baskets to that encouraged the use of lantana among marginalised com- furniture, were developed. #e average number of person- munities in southern India. A number of forest dwelling days of employment in lantana craft increased from about

^EWTTGPVEQPUGTXCVKQP Photo: Ramesh Kannan | Infographic: Pallavi Baasri

Schematic representation of the temporal dymanics of an invasive species, showing the change in associated ecological costs over time; also shown is the pattern of bene"ts from the invasive species (in the event of its use)

30 in 2004 to more than 80 in 2006. Over the same period, the species, from one of exclusion to that of inclusion may be mean annual per capita income from lantana increased from pragmatic, particularly in tropical human-dominate landsc- US$ 17.90 to US$ 63.93, a signi!cant jump. apes where low income and the abundance of the invasive species constrain e$ective control, while the lack of rural Viewed in the context of managing invasive species, this initi- options encourages utilisation. For example, Geesing and ative o$ers an unconventional approach to minimising the net colleagues defend the use of Prosopis thus, “Notwithstand- cost: the use of lantana could allow for the regeneration and ing the unquestionable ecological changes produced by recruitment of native species and mitigate other ecosystem da- Prosopis invasion, where the species has been introduced it mages such as pollinator loss; the harvest of lantana could pro- is necessary to make the best of a situation that is hardly vide a window of opportunity for the regeneration of at least reversible.” some native plants; and the extraction of the weed might help in reducing the incidence of forest !res, which otherwise are * R Uma Shaanker is at the Department of Crop Physiology, and School of Ecology and Conservation, University of Agricultural Sciences, Bangalore, fanned by lantana and also o$er greater accessibility for both India. Mail at [email protected] animals as well as people. Of course, these mitigating e$ects would depend on the scale and the ways in which lantana is * Gladwin Joseph, NA Aravind and R Kannan are at Ashoka Trust for Research in Ecology and the Environment, Bangalore, India. eventually used. * KN Ganeshaiah is at the Department of Forestry and Environmental (TQOGZENWUKQPVQKPENWUKQP Sciences, and School of Ecology and Conservation, University of Agricultural Sciences, Bangalore, India. Any action (including promoting the use of the invasive) that can reduce the ecological cost of the invasive is a potentially useful strategy. A shift in our view of managing invasive

EWTTGPVEQPUGTXCVKQP^ HGCVWTG^5WTGUJ$CDW#OKV.QXG %JGTWMWTK4CIJCXGPFTC$CDW 4GUQNWVKQPVQ4GUVQTG

1RKDOIPHDVXUHVZRUNLQ Protected areas (PAs) across India today are invaded by alien invasive species HUDGLFDWLQJSHUVLVWHQWLQYD that include Lantana camara, Mikania micrantha, Chromolaena odorata, Ageratum GHUV&RPSOHWHHUDGLFDWLRQ conyzoides, Parthenium hysterophorus and Hyptis suaveolens. Although di%cult, ZLWKORFDOSDUWLFLSDWLRQLV restoring landscapes colonized by invasive species is important for the conserva- WKHRQO\ORQJWHUPVROXWLRQ tion of biodiversity and for the sustenance of other ecosystem services. :HHGLQIHVWHGODQGVFDSHV ZLWKGUDVWLFDOO\GLPLQLVKHG Lantana (Lantana camara), one of the world’s most troublesome weeds, has virtu- HFRV\VWHPIXQFWLRQVRIIHU ally invaded all the tropical and subtropical regions of India. Although attempts XQLTXHFKDOOHQJHVDQGRS have been made to control lantana by physical, chemical and biological methods, SRUWXQLWLHVIRUUHVWRUDWLRQ there has been little success either in its control or in the prevention of its spread. :HHGVKLQGHUWKHUHJHQHU #e control methods in use at present remain inadquate and infeasible owing to DWLRQRIDSURGXFWLYHQDWLYH the sheer magnitude of the infestations, low land values, and lack of incentives for FRPPXQLW\ control. #e lack of understanding of the species’ biology and lack of site-speci!c information of its ecology are major bottlenecks in developing e$ective tools for its management. It has yet to be recognised, for instance, that habitat degradation has triggered the invasion of lantana and that a !nal solution has to come in the form of habitat restoration. #e methods that have been in practice for controlling lantana typically included chopping the main stem at the base, clipping aerial shoots and burning the clumps, and uprooting. Although these methods do bring about a short term reduction in the cover of lantana, with the onset of monsoons, profuse coppicing from multiple growing points occurs. Clipping is totally ine$ective and only causes the clumps to spread and become hardier. Burn- ing results in coppicing from the buried meristematic zone and also increases soil erosion. Burning on a large scale is normally not resorted to in PAs, besides the fact that this practice may actually be advantageous to the weed in the long run. Uprooting, besides being labor intensive, disturbs the soil, exposes the buried seeds of lantana, and leads to their rapid germination.

Building on past experience with lantana management, and on the basis of a sys- tematic assessment of its biology (the magnitude of its spread, its phenology, the distribution of growth points from which the plant resprouts or coppices, its archi- tecture-including root system-soil microbiology and seed dispersal strategies) we ventured to develop a new management strategy, the ‘cut rootstock method’. #is method involves the of lantana by cutting below the rootstock (see photo- graph), which we determined, experimentally, to be the most e$ective way of preventing it from coppicing. #is is followed by ecological restoration using locally available legumes and grasses. Landscapes where lantana has been removed using this method need to be re-weeded, especially under trees where the bird dispersers of lantana perch. lantana removal must be followed by restoration of weed-free landscapes, preferably of grassland or forest communities depending on the needs of stakeholders, to prevent re invasion by lantana or secondary invasion by other alien species. #e new strategy was developed using experimental

plots at Laldhang and Jhirna at Corbett Tiger Reserve and has subsequently been Pallavi Baasri

^EWTTGPVEQPUGTXCVKQP implemented successfully in other parts of Corbett (Uttara- gumes, with scattered trees. At Laldhang, the Corbett khand), Kalesar National Park (Haryana) and Satpura Tiger management has scaled up the restoration plot to 64 ha. Reserve (Madhya Pradesh). #e area was fenced o$ due to frequent instances of cattle grazing from nearby villages. #is plot now harbours luxu- #e two experimental plots at Corbett have been the "agships riant grassland with few interspersed trees and diverse of this control strategy that involved e$ective removal and avifauna. #e Jhirna plot was left unfenced because there ecological restoration of ‘weed-free landscapes’. #e plots were was no cattle grazing. #is plot is now frequented by large browsed by chital and there was some mortality, but it was herds of such browsers as chital and sambar, which form not a serious impediment because herbivore numbers were the major prey base for carnivores. So far there have been small, since this area had been a settlement till quite recently. several recorded tiger sightings at Jhirna in the vicinity of We were able to achieve high survival rates (measured on an the restoration plot (including carcasses of kills within the annual basis) for tree saplings because of modi!cation of soil plots). #e two plots established at Jhirna and Laldhang, conditions and the habitat by short grasses such as Penisetum using the integrated control and restoration strategy out- ciliaris, Eulaliopsis binata, Heteropogon contortus, Paspalidium lined above, are now used for demonstration of the tech- scrobicularis, Cynodon dactylon, and Sporobolus indicus, as well nique. At both sites the original relative density of lantana as leguminous species like Desmodium gangeticum, D. tri!o- clumps varied from 80% to 100% and the areas were devoid rum, Flemingia bracteata, F. fruticosa, F. macrophylla, Indigof- of native species except for a few scattered trees that served era astragalina, and I. hirsuta). #e experimental plots are now as perches for bird dispersers of lantana. Within 2 years fully covered with a carpet of several grass species and le- of the restoration program at Corbett (June 2005 to June

EWTTGPVEQPUGTXCVKQP^ 2007), both demonstration plots harbored grassland communities with annual and perennial native grasses and legumes. Several workshops and hands-on training programs were also held to enable foresters and park managers to scale up the lantana control and restoration measures, with !eld visits to the plots and demonstration of the technique employed. Various aspects of this model including the costs and bene!ts of clearing lantana and then converting the landscape into productive grasslands and woodlands, were highlighted to gain wider acceptance for the model. A simple manual was developed and widely circulated to aid foresters in removing lantana by the cut-rootstock method and to identify the grasses and legumes used in the Corbett model.

Subsequently, other forest managers of Uttarakhand State have adopted this technique. #ese forests include the

Rajaji National Park, Landsdowne Forest Division, and Suresh Babu Nainital Forest Division. In Corbett itself, lantana has Top: #e Laldhang experimental plot as a lantana monoculture been removed from over 2500 ha and restoration of these Above: As luxuriant grassland with interspersed trees after restoration patches is in progress under the supervision of the park management. #e advantages of the new management strategy over other control methods currently used are its enhanced biological productivity, particularly in terms of cost e$ectiveness, its simplicity and ease of adoption and palatable species of grasses and legumes; greater retention of the successful control of lantana that the technique ensures, soil moisture; prevention of soil erosion; enrichment of native without the use of chemicals or exotic biological control biodiversity; the increased frequency of wildlife sightings; and agents, and with minimal disturbance of the soil. One of enhanced recreational values, since Corbett is a favorite desti- the major reasons for the popularity of the cut-rootstock nation for eco-tourists and ornithologists. method has been the fact that the restored patches do not require care after the !rst two years, since all the species We anticipate that our observations on lantana management used are native. Forest departments of other states, con- in Corbett and the success of the Corbett model will help in vinced by the e$ectiveness of the approach, have already developing similar management strategies for other PAs that removed lantana from several hundred hectares of forest are presently overrun by lantana and also other weeds such land, particularly around Panchmarhi Biosphere Reserve as Mikania micrantha, Chromolaena odorata and Parthenium in Madhya Pradesh and Kalesar National Park in Haryana. hysterophorus. However, any restoration program for these However, as we have learned from our experience in Cor- other invasive species would also need to be informed by an bett, the ultimate success of such a program relies heavily understanding of the biology of the invader, the local soil and on the conviction and motivation of stakeholders. Land- micro climatic conditions, the status of the ecosystem, the scapes degraded by invasive species are often extensive, and larger landscape matrix, and most importantly, the require- even as weeds are eradicated from one area, propagule pres- ments of the stakeholders. sure and thus, reinvasion, can persist due to the continuing presence of weeds in other areas. * Suresh Babu is a Research Scientist with the Centre of Excellence Program, Center for Environmental Management of Degraded Ecosystems, University of Delhi, India. Mail at [email protected] A well-coordinated removal program followed by restoration at suitably large scales is necessary to tilt the scales in * Amit Love is a Research Scientist with the Centre of Excellence Program, Center for Environmental Management of Degraded Ecosystems, University of Delhi, favor of native species. A strong determination by the park India. managers was crucial for the success of such a program. #e bene!ts of lantana eradication and subsequent res- * Cherukuri Raghavendra Babu is Emeritus Professor at the Centre of Excellence Program, Center for Environmental Management of Degraded Ecosystems, toration to grasslands in Corbett have been many: University of Delhi, India.

^EWTTGPVEQPUGTXCVKQP UPKRRGVU^&KF[QWMPQY!

&RQWUROOLQJ,QYDVLYHV

#e loud mating calls of introduced Coqui frogs cause sleepless nights for residents in Hawaii. #e frog problem has become so acute that it has reduced the value of invaded properties. Locals spray citric acid or bleach to kill the frogs, and scientists are now experimenting with infecting .LOOHU&DWV the frogs with a nematode parasite !e domestic cat is a widespread invader globally, and causes enormous found in their native Puerto Rico. and often undocumented damage to native fauna......

Populations of coconut rhinoceros Feral as well as pet cats prey on native common methods of control are kill- beetle accidentally introduced to fauna, primarily birds and small to ing of cats and the ‘trap-neuter-release’ islands of the South Paci!c are kept medium-sized mammals. Predation by (TNR) method. While animal rights in check with bio-control measures. Researchers feed a virus from Mala- cats is particularly critical on islands. In groups condemn cat killing, studies ysia to healthy beetles that are then Britain alone, cats (9 million) are resp- have shown that the TNR method is released to infect the rest of the onsible for killing approximately 275 ine$ective in controlling cat populat- population. #e virus destroys the million animals a year. One domestic ions. Various organisations urge less stomach walls, causing beetles to cat in New Zealand was documented agressive methods like not feeding stop eating. to bring in 558 animals from a radius stray cats and keeping domestic cats ...... of 600 mt around its home over a 17- indoors. #e solution to the cat prob- #e mile-a-minute weed (Mikania year lifetime. lem might lie in a combination of me- micrantha), a fast-growing creeper, thods, including accepting novel (and was introduced to India by the Brit- #ough listed as one of the 100 worst grisly?) alternatives like the cat-eating ish to camou"age airstrips during invaders worldwide by the IUCN, festival in Peru or the underground World War II. Native to Central management and eradication of feral cat-fur trade in China. and South America, is now found cats remains controversial. #e most across South Asia and the Paci!c...... ),6+<%86,1(66 #e arrival of mosquitos in Hawaii with the !rst Europeans, and the attracted to each other through smell, avian malaria that followed, took and scientists are using this to try and a massive toll on the endemic bird control them in Minnesotta, USA. #e diversity, even causing extinctions. idea is to release carp pheromones in targeted areas of the rivers to lure the !sh into concentrations, where they can Native to Europe and be netted. A more long term-solution northern Asia, Common carp (Cyprinus is being attempted in Australia, where carpio) are one of the earliest widely-int- carp are being genetically modi!ed so roduced !sh. #ey are a problem species they produce only male o$spring. 6SRWWHGGHHUVZLPDFURVVVWUHWFKHVRI in their introduced range, causing &DUS OHIW DUHLQWURGXFHGLQ,QGLDQULYHUV VHDEHWZHHQLVODQGVXSWRNPVDSDUW damage to plant and animal communi- E\WKH)LVKHULHV'HSDUWPHQWWRLQFUHDVH LQWKH$QGDPDQV ties in freshwater ecosystems. Carp are UHYHQXHRIORFDOÀVKHUV Carp: Robin Abraham | Chital: Manish Chandi | Cat: Invasive Animals Cooperative Research Centre

EWTTGPVEQPUGTXCVKQP^ HGCVWTG^%JCTNGU2GTTKPIU*CTQNF/QQPG[ /CTM9KNNKCOUQP 7KH(FRQRPLFV RI,QYDVLYHV e Nature Conservancy # ,I ZHWDNHWKHH[SHQGLWXUHWRFRXQWHUSHVWVLQDJULFXOWXUHIRUHVWU\DQGÀVK HULHVDORQJZLWKWKHRXWSXWORVWWKURXJKLQYDVLYHSHVWVDQGSDWKRJHQVLQDOO VHFWRUVDQGDGGWRWKDWWKHFRVWVRI ERWKHPHUJHQWDQGUHFXUUHQWGLVHDVHVRI LQWHUQDWLRQDORULJLQWKHSUREOHPRI LQYDVLYHVSHFLHVPDNHVDOORWKHUHQYL URQPHQWDOSUREOHPVSDOHLQWRLQVLJQLÀFDQFH

^EWTTGPVEQPUGTXCVKQP Invasive species are de!ned by the Convention of Biologi- of trade along those routes has increased the frequency with cal Diversity as “.. those alien species which threaten eco- which introductions are repeated. Species introductions are systems, habitats or species”. If we take the expenditure an externality of trade whose cost depends heavily on the to counter pests in agriculture, forestry and !sheries along way that ecosystems are exploited, both because that in"u- with the output lost through invasive pests and pathogens ences the vulnerability of those systems to invasion, and in all sectors, and add to that the costs of both emergent because it determines the value at risk from invasions. and recurrent human diseases of international origin, the problem of invasive species makes all other environmental 7KHLQWURGXFWLRQRI DQ\JLYHQVSHFLHVKDVYHU\ problems pale into insigni!cance. GLIIHUHQWFRQVHTXHQFHVLQODQGVFDSHVH[SORLWHG IRUGLVWLQFWSXUSRVHV #e ecological and economic dimensions of the problem of invasive species are connected at di$erent levels. #e ecological changes that lead ecosystems to be more vulnerable to the impacts of invasions, the fragmentation and disturbance of habitats, loss of biodiversity and increasing pollution burdens, are a direct consequence of economic behaviour. #e ecological mechanism connecting invasive species, functional diversity and ecosystem resilience, the rate at which species are dispersed, is highly correlated with the growth of trade, transport and travel. #e main consequence of a loss of resilience is a reduction in the capacity of ecosystems to maintain functionality and the production of ecosystem services over a range of environmental conditions. #is has direct implications for the value of both output and the underlying ecological assets—the natural capi- A plant pathogen speci!c to a particular cultivated crop, for tal—of the system. At every level, the ecological impacts example, may have no implications outside of agricultural ar- of the economic activities involved are incidental to and eas, but may be devastating within those areas. Indeed, agro- are ignored by the actors concerned. ecosystems are typically the most vulnerable to invasive species, though also the most likely to be protected through #ey are said to be externalities of the market transactions controls. For the agricultural sector, for example, invasive involved, meaning that they are not taken into account by species cause damage costs equal to around 50% of agri- the people engaged in those transactions. #e economic cultural GDP in the USA and Australia, 30% in the UK, problem of biological invasions is !rst to understand the but between 80% and 110% of agricultural GDP in South nature of invasive species externalities and why they occur, Africa, India and Brazil. To date, however, there are almost second to evaluate the consequences they have for human no studies of the implicit cost of habitat fragmentation, well-being, and third to develop policies and instruments disturbance, or other landscape changes that a$ect the ease for their internalisation. with which introduced species can establish and spread.

#e economic forces that drive the problem of biological Where there is uncertainty about the likelihood of both invasions include trends in land use that a$ect the vulne- introductions and the potential consequences of establish- rability or susceptibility of ecosystems, trends in trade, ment and spread, the economic problem resolves into an transport and travel that a$ect the likelihood of species evaluation of the relative net bene!ts of mitigation versus introductions, and trends in technology that a$ect species’ adaptation strategies: of preventive action versus control af- impacts. While globalisation has implications for all three, ter the fact. What makes the problem particularly di%cult it is especially important for the second, in"uencing both is precisely the uncertainty attaching to several aspects of the species involved in exchanges and the likelihood of the invasion process. #e historic likelihood that any given their becoming invasive. #e development of new trade introduced species will establish, spread and in"ict appre- routes has led to the introduction of new species either de- ciable harm on the host system is low. However, the few liberately or accidentally, while the growth in the volume species that do turn out to be damaging can be very harm-

EWTTGPVEQPUGTXCVKQP^ ful indeed—as was the case with the plague in Europe, smallpox, measles and typhus in the Americas, or the Spanish Flu world-wide.

#ree related issues turn out to be important in the theory of invasive species control. #e !rst is the relative costs and bene!ts of alternative strategies and, in particular, the relative costs and bene!ts of mitigation versus adaptation strategies. #e second is the degree of uncertainty involved, and the third is the rapidity and spatial extent of the potential spread of the invasive species.

In the absence of reliable estimates of the net bene!ts of investment in the defensive capabilities of ecosystems the- mselves, the relative costs and bene!ts of alternative strategies generally involve a comparison of net bene!ts of

But where the risks are not known, it is optimal to adopt a random audit approach. In an evolutionary system where the capacity to predict the consequences of novel events is limited by the lack of historical precedents, building that capacity through both monitoring and experimentation is an essential part of the policy toolkit. Biological invasions are an externality of international trade, and the solution to the problem requires policies to address that fact directly. #ese imply international cooperation, which means colla- borative action both in terms of the multilateral agreements governing trade (the General Agreement on Tari$s and Trade) and the e$ects of trade (the Sanitary and Phytosa- nitary Agreement, and the International Plant Protection Convention), and of the intergovernmental organisations established to address di$erent dimensions of the invasive species problem. For virulent human or animal pathogens inspection and interception or detection and eradication versus the control of established invaders. Of the three strategies-inspection (to prevent introduction), detection (to identify and eradicate species that have got past the border but have not yet spread) and control (management of species that have established and spread - inspection and detection are generally substitutes. Reducing the cost of one of these two strategies will increase the optimal ef- fort devoted to it and reduce the optimal e$ort devoted to the other. However, both are substitutes for the control of established populations. #e optimal inspection strategy depends on the level of uncertainty attaching to commodity groups and trade routes. Where the risks associated with particular commodity groups or trade routes are known, then a targeted inspection strategy makes sense.

^EWTTGPVEQPUGTXCVKQP Page 14: Cheatgrass, Bromus tectorum, in Dinosaur National that are likely to spread globally the scale at which the pro- Monument, Utah. It has spread from Southern Eaurope to Russia, Asia, blem needs to be addressed is clearly global. At the same North America, Japan, South Africa, Australia, New Zealand, Iceland, and Greenland, and displaces many native species. time, however, many introduced species spread locally at fast enough rates to make them problematic at that scale, Page 15: #e zebra mussel, Dreissena polymorpha, introduced to the Great but have no implications beyond that. Application of the Lakes in ships ballast, causes millions of dollars of damage every year. subsidiarity principle implies that problems of that sort be Facing Page; clockwise from top: Fountain grass, Penisetum setaceum, is a dealt with at a local scale. Between such polar cases, how- major "re threat to many of Hawaii’s natural areas. Tamarisk, Tamarix ever, lie problems that occur over a wide range of scales. #e ramosissima, from southern Eurasia, has invaded riparian areas in many dryland environments. Water hyacinth, Eichhornia Crassipes, originally challenge in this for the economic, epidemiological and eco- from South America, has spread widely through Africa, Asia, and North logical sciences is to determine the spatial and temporal America. In India it has invaded large areas of the Kerala Backwaters. scale of the problem-including its causes and e$ects-and

Above: #e red palm mite, Raoiella indica, moved by trade and travel to analyze both the problem and the policy and manage- between Caribbean islands. ment options accordingly.

Global protection against many invasive species risks is a public good of a very special kind-a ‘weakest link public good’. Because global protection is a weakest link public good, the lower the capacity of poor countries to deal with damaging and rapidly-spreading invasive species, the greater the exposure of all their trading partners. It follows that the more closely integrated is the global system, the greater the incentive to high income countries to build capacity in the weakest links in the chain. In the case of human, animal and plant pathogens, the risk of infection or re-infection can be reduced by direct support of the sanitary and phytosanitary capabilities of low-income trading partners.

* Charles Perrings is at the School of Life Sciences, Arizona State University, Tempe, USA. Mail at [email protected] Further reading: * Harold Mooney is at the Department of Biological Sciences, Stanford Uni- Perrings C, HA Mooney, & MH Williamson. 2010. versity, Stanford, USA. Bioinvasions and globalization: Ecology, economics, management, and policy. Oxford: Oxford University Press. * Mark Williamson is at the Department of Biology, University of York, UK.

EWTTGPVEQPUGTXCVKQP^ HGCVWTG^0CXGGP0CODQQVJTK-CTVKM5JCPMGT Kalyani Ganapathy

DGVYGGPVJGFGXKNCPFVJGFGGRDNWGUGC

^EWTTGPVEQPUGTXCVKQP *WOCPOGFKCVGFOCTKPG KPXCUKQPUCTGKPETGCUKPIN[ RGTEGKXGFCUGEQNQIKECNN[ CPFGEQPQOKECNN[FGXCUVCV KPI6JG[JCXGDGGPKFGPVK ſGFCUQPGQHVJGVQRſXG VJTGCVUVQOCTKPGGEQU[U VGOUINQDCNN[ECWUKPIURG EKGUGZVKPEVKQPUCPFDKQVKE JQOQIGPKUCVKQP

Right: Kaneohe Bay, Hawaii: alga growth rate of 260 metres per year; covers 50% of

substrate in many areas J K Patterson

Ocean-going vessels, which can account for the movement of 7,000-10,000 species at a time, are the single most important pathway for the dispersal of marine organisms. In addition, the intentional introduction of species for aquaculture is becoming an important mode of spread of potentially invasive species. One such species introduced to India is the seaweed Kappaphycus alvarezii.

.DSSDSK\FXVDOYDUH]LLLQ,QGLD K. alvarezii was !rst introduced by the Central Salt and Marine Research Institute to Gujarat, in 1993, and later to Mandapam, in 1995, for large-scale commercial culture. K. alvarezii is used to produce the gelling agent, kappa carrageenan, which, in turn, is used in industrial gums, and in products such as soft drinks. #e entrepreneurial venture of seaweed cultivation was undertaken by Pepsi Foods Limited (PFL) along with the Central Salt and Marine Chemi- cals Research Institute (CSMCRI) as a livelihood option for Self Help Groups (SHG) on an attractive buy-back arrangement. Large-scale culture of the species began in 2001 in the Palk Bay waters o$ Mandapam (which supports coral reefs and seagrass beds). By this time, the species had been classi!ed as an invasive species and had wreaked havoc in the reefs of the Hawaiian and Caribbean islands. At the Kaneohe Bay, Hawaii, the alga is spreading at the rate of about 260 metres per year, and covers 50% of the benthic substrate in many areas. It can grow over, smother, and prevent fresh establishment by both coral larvae, and other benthic invertebrates and its invasive potential and ability to re-grow has aroused the concern of researchers.

Recent studies and our own in situ observations have shown that the species has spread to the marine protected areas within the Gulf of Mannar Biosphere Re- serve. #e alga is growing extensively on the branching coral colonies of Acropora formosa and A. nobilis, smothering the corals beneath. We found that all coral polyps below the algal mat were dead. #e alga grows so densely and compactly on the coral colonies that, once well-established, it is impossible to separate the alga from the coral colony without causing severe damage or breaking. If left un- checked, and if no immediate remedial action is taken, the alga could well

EWTTGPVEQPUGTXCVKQP^ spread to other parts of the marine protected area and lead to large-scale ecosystem phase shifts and undermine the functionality of coral reefs. Some scientists (including Dr. APJ Abdul Kalam, former President of India), have hailed Kap- paphycus cultivation as an important alternate livelihood option for communities.

Naveen Namboothri #e culture of the alga is a lucrative activity and comes with a promising buy- back package, and central and state government support.

#e entire issue of K. alvarezii raises questions about the integrity and responsi- bilities of science, scientists and people in power. While the idea of introducing K. alvarezii to provide a livelihood alternative for resource-dependent communities is certainly well-intended, the scienti!c information and research to support and justify its introduction is weak and unsubstantiated. #e most audacious justi!cation so far provided for the introduction of K. alvarezii was the discovery of a few strands of the species in the Andaman and Nicobar islands, leading to its being declared a native species.

If immediate measures are not undertaken to check the spread of large-scale culture, at least till the species is conclusively proven to be harmless, it could lead to complications in future management. With more people depending on the seaweed for livelihoods, con"icts could evolve if management policies are to be put in place.

* Naveen Namboothri is a Post Doctoral Fellow at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India. Mail at [email protected]

* Kartik Shanker is an Associate Professor at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India.

^EWTTGPVEQPUGTXCVKQP RGTURGEVKXG^)[CP2TCMCUJ5JCTOC #54CIJWDCPUJK *QY.CPVCPCKPXCFGF+PFKC

#ere are a growing number of invasive species in ecosystems around the world. One such invasive species is Lantana camara. Key biological attributes of lantana that make this species among the world’s 100 worst invasive weeds include !tness homeostasis, phenotypic plasticity, widespread dispersal by birds that feed on its fruit, a broad geographic range, vegetative reproduction, !re tolerance, ability to compete e$ectively with the native "ora, and allelopathy.

It is not clear how lantana arrived in India, although there are anecdotal references to the introduction of lantana as an ornamental in the early 19th century. lantana may have been introduced into India on multiple occasions—as an ornamental plant in Coorg and as a hedge plant in Calcutta. We can trace its spread in Nainital district of India: it was introduced around 1905; till 1911 it was con!ned to hedges and was sparsely distributed; by 1929 it had become widespread, forming dense thickets in farms, pastures, fallows, and forest areas. Lantana has invaded most Indian pasture lands (13.2 million ha) besides forest and fallow areas, and the cost of its control is estimated to be US$ 70 per hectare. Indian populations of lantana have been around for a long time (about 2 centuries). #is would suggest that lantana has had time to evolve and become locally adapted. However, it is di%cult to attribute the success of lantana to any one factor alone, and one could invoke di$erent hypotheses to explain its success at di$erent stages of the invasion process (see over- leaf).

Consequences of lantana invasion, particularly on the native "ora, are little understood and need to be studied. Our studies provide a qualitative and quantitative overview of the e$ects of lantana on ecosystem structure and function in tropical dry forests of northern India. Many species of tropical dry forests have small local populations, but several of them exhibit declining or even severely depleted populations in lantana-invaded locations. Such invasions create demographic instability among native tree species, reduce tree diversity, and could even change the structure of the forest in the near future (examples of species with declining Kalyani Ganapathy populations include Acacia auriculiformis, Adina cordifolia, Boswellia serrata, Briedelia retusa, Buchanania lanzan, 7UDQVLWLRQEHWZHHQ6WDJHVRI/DQWDQD,QYDVLRQ Kalyani Ganapathy

)OXFWXDWLQJ5HVRXUFH+\SRWKHVLV (QHP\5HOHDVH+\SRWKHVLV (YROXWLRQRI,QFUHDVHG 3UHVHQFHRI(PSW\1LFKHV &RPSHWLWLYH$ELOLW\!1RYHO:HDSRQV

Biologists have invoked a number of potential explanations, or hypotheses, for the success of invasive species. Fluctuating Resource Hypothesis: #e ability of invasive species to preemptively take advantage of resources (light, soil nutri- ents, space) that become available following a disturbance. Presence of Empty Niches: Some species-poor ecosystems, such as oceanic islands, are thought to be more vulnerable to invasions than species-rich ecosystems. Enemy Release Hypothesis: Invasive species are often thought to be successful in their introduced environments due to the lack of natural enemies to keep them in check. Evolution of Increased Competitive Ability: Freedom from enemies (herbivores or predators) might allow introduced species to allocate resources to growing larger, or faster. Novel Weapons: Invasives may spread rapidly in new environments due to weapons like antimicrobial or allelopathic chemicals they exude from roots, which may inhibit other species in their new environments-the Allelopathic Advantage Against Resident Species of some invasive species is an example.

Cassia "stula, Elaeodendron glaucum, Emblica o$-cinalis, this, in turn, favours the growth of lantana. Our research Eriolena quinquelaris, Hardwickia binata, Miliusa tomentosa, suggests the need for prioritization of issues, designing of Schrebera swietenioides). Lantana can also have a devastating hierarchical management, and adaptive management strate- impact on the rich herbaceous understory. gies in response to lantana invasion. New research approaches warrant further investigation with more in situ experimenta- We also observed that lantana litter inputs increase with tion. #ere is also an urgent need for information increasing lantana cover and that the chemical composi- regarding the current and the potential distribution of lan- tion of lantana litter is very di$erent from the chemical tana, for its monitoring, control, and possible eradication. All composition of native forest species litter. #e high nitro- this can only be possible through increased public awareness gen and low lignin content of lantana litter and the favo- of the harmful impacts of lantana on our landscapes. Amal- rable microclimate beneath lantana canopies favour faster gamation of all this will create a promising environment in decomposition and release of nitrogen. #is alteration in which lantana research can be promoted, funded, and nur- litter inputs and chemistry beneath lantana positively and tured through a ‘Lantana working group’ for India. signi!cantly alter soil nitrogen availability, nitrogen min- eralization, and total soil nitrogen, leading to a positive * Gyan Prakash Sharma is at the Department of Environmental Biology Univer- sity of Delhi, New Delhi, India. Mail at [email protected] feedback: lantana increases soil nitrogen availability, and * AS Raghubanshi is a Professor of Botany at Banaras Hindu University, Vara- nasi, India.

^EWTTGPVEQPUGTXCVKQP RGTURGEVKXG^4CWH#NK +PXCFKPIVJG#PFCOCPU

)URPZHHGVWRHOHSKDQWVDQLPDOVEURXJKWLQE\KXPDQVFDXVH HFRQRPLFDQGHQYLURQPHQWDOGDPDJHLQWKH$QGDPDQ,VODQGV Manish Chandi Mohwa-Manilkara littoralis on limestone rock, Cape Strachan, middle Andaman Island

Invasive species are especially problematic on islands. Islands While some invasives spread by extending their ranges in tend to be depauperate of species, and this enables a lot of the areas where they have been introduced, the most im- introduced species to take hold. Invasives arrive by various portant factor is the availability of transport vectors. #ese means. #ey are either deliberately introduced (as household could be domestic animals passing through with parasites pets or ornamental plants), or arrive as commensals (e.g., rats, on them. #ese could also be trucks and cars; the presence mice), foodgrain contaminants (as weeds), or in ship-water of road networks is a key factor in the spread of invasives. ballast. Ship water ballast is estimated to carry up to 10,000 In the Indian subcontinent, knowledge of invasives is basi- species daily to areas outside their native range, making this cally con!ned to ‘page 3’ plants. #e well-known ones here one of the main pathways of introduction. Islands also have are Chromolaema odorata (eupatorium), Lantana camara a large number of range-restricted endemic species, that mig- (lantana), Eicchornia crassipes (water hyacinth) and Mika- ht face extinction when competition with invasives occurs. nia micrantha (mile-a-minute weed). Every protected area Even invasives that do not attract attention in mainland ar- management plan gives a laundry list of these plants, with eas can become troublesome on islands. #is is specially the a recommendation that they ‘be controlled’. How this is case when there are no predators, and endemics have evolved to be done is never speci!ed. Animal invasives are largely in the absence of predators. ignored, because of the perception that these are common

EWTTGPVEQPUGTXCVKQP^ animals and cannot be called invasives. #ese include feral were released into the forest and became feral. On Interview dogs and cats, which cause great damage to our natural Island these elephants have damaged the vegetation by deba- ecosystems. rking and knocking down trees. Moreover, the deer here will not allow any regeneration. #e result is an annual rate of for- While hardly noticed on the Indian mainland, bird and est loss on Interview Island signi!cant enough to be detected animal invasives have begun to play a signi!cant role in on satellite imagery. Cats, dogs, goats, and cattle have all be- both the ecology and the economics of the Andaman come feral in di$erent parts of the islands. Dogs form packs Islands. A total of 12 bird species have been introduced and have been known to attack humans. #ey also attack sea into the Andamans, mainly at the end of the 19th century. turtles that come ashore to lay eggs, in addition to digging up Of these, 5 are still found there, 6 have disappeared, and and eating the eggs. While no study has been done on cats, the status of 1 is unknown. Of the !ve still found, two they probably cause serious mortality among the bird species are invasive. #e most ubiquitous of the bird invasives found in the islands. Goats contribute to the degradation of found in South Andaman is the common mynah (Acri- Barren Island. #is island is volcanic, and is not inhabited. dotheres tristis). #is species of the Indian mainland has British sailors released the goats there in the mid-1800s as spread all over Southeast Asia, parts of Australia and New insurance against any future shipwreck in the area. #ey were Zealand, and the island groups of the South Paci!c. #ey subsequently introduced on Narcondam Island in the 1970s, are known to prey on the eggs and nestlings of other bird where they began spreading; luckily the Andaman and Nicobar species, and may compete in the Andamans with indig- Administration acted on a report by Ravi Sankaran detailing enous hole nesters such as the glossy starling and the black the damage they did, and has taken steps to eradicate them. #e woodpecker. #ey are listed as being among the 100 most control of chital has been recommended for a while, but the invasive species in the world. permissions from MOEF are not forthcoming yet. #e control of dogs has also not been undertaken yet; fear of animal rights $PXFKPRUHUHFHQWLQYDGHULVWKHKRXVH activists seems to play a large role here. FURZ6HYHQLQGLYLGXDOVZHUHVHHQÁ\LQJ RIIDERDWLQ3RUW%ODLULQ7LPHO\ I will not go into the various plant species that have become DFWLRQZDVQRWWDNHQWRHUDGLFDWHWKHP invasive here, save to state that even on Great Nicobar island, DQGQRZWKH\QXPEHUVHYHUDOKXQGUHG a short study found 12 invasive weed species. Most of these were contaminants of seed material that had been brought In other island ecosystems where crows have become es- there. Escaped ornamental plants have also caused major prob- tablished they are agricultural pests as well as disease vec- lems around Port Blair. What is required urgently is a national tors. House crows were also introduced into the Nicobars policy to deal with invasives, especially in these island areas in the past, though the exact date is not known. Of the that are particularly vulnerable. #is policy would have to con- 13 mammal species that were introduced here-including sider invasion pathways, vectors of spread, and legal and cost- domestic animals-two, (leopard and hog deer) have died e$ective mechanisms for control and eradication. out, but most of the rest are problematic. #e most ubiq- * Rauf Ali is a trustee at the Foundation for Ecological uitous of these is the chital (Axis axis). In the Andamans Research, Advocacy and Learning (FERAL), the regeneration of forests is severely a$ected wherever Pondicherry, India. chital are common, since they browse on seedlings, even Mail at [email protected] in evergreen forest. #e only two species they appear to avoid are Pongamia pinnata, a coastal evergreen species, and Lagerstromia hypoleuca, a deciduous species. As a result, large areas that were originally semi-evergreen forest have become deciduous in character due to the pre-dominance of Lagerstromia hypoleuca.

Elephants were used for timber operations on Interview Island, and in North Andaman. When the timber operator in that area went bankrupt in 1962, the elephants

^EWTTGPVEQPUGTXCVKQP Kalyani Ganapathy URQVNKIJV^%JCTNKG5JCEMNGVQP,COGU)CODK\C 6CEMNKPI+PXCUKXG5RGEKGU VJGUVQT[QHCUJTWDKP5QWVJ#HTKEC Kalyani Ganapathy 6RPHWLPHQDWLYHSODQWVUXQUDPSDQWXQGHU FKDQJLQJFLUFXPVWDQFHVEHFRPLQJHFRORJLFDO GLVDVWHUV%XWKRZGRHVRQHFRQWUROWKLVZKHQ WKHSODQWQRZHQKDQFHVORFDOOLYHOLKRRGV"

Invasive plant species are a considerable threat to productive land use and economic returns in many areas of the world. #us they are frequently viewed within a degradation paradigm, having been facilitated by inappropriate land use practices resulting in reduced useful productivity. For example, the economic cost of alien invasive species has been estimated at being close to 5% of world GDP. However, not all invasives are alien. For example, at least 10% of South Africa is encroached by indigenous species that form almost monospeci!c stands over large areas, and this encroachment is increasing through perceived injudicious land use practices. #erefore the economic costs of invasive species in general are likely to be far

^EWTTGPVEQPUGTXCVKQP higher. Given the overwhelmingly ne- tive contributions of the absence of paired non-invaded ones, largely due to gative narratives pertaining to the eco- contours in arable !elds on hilly slopes, the increased richness of forb species. nomic impacts of invasive species, the and weak control of runo$ from roads #e invaded areas had six species exc- social and sometimes ecological dime- has not been investigated). Conseque- lusive to it not found outside the Eury- nsions of these processes receive consi- ntly, in 2004, the central government ops patches, whereas the open grassla- derably less attention. Consequently, sought to involve local households in nds had only one species that was not eradication programmes are designed on a land rehabilitation and poverty relief found in invaded areas. #e frequency economic imperatives with insu%cient programme. After basic consultations of livestock dung in open grasslands consideration of the social and ecologi- they agreed to hire local labour to man- (14.6 + 3.4 %) was almost double that cal implications. Frequently, the alien ually remove approximately 1,500 ha recorded in the invaded areas (8.5 + species are cleared by manual, biological of Euryops as a means to create more 2.5 %). Cluster analysis of the species or chemical means, but without altering grazing for the livestock and so reduce composition indicated that none of the the original land use practices that en- the grazing impact per unit area. Al- designated groupings were exclusive to couraged the invasion in the !rst place. most US$1 million was allocated to the invaded or non-invaded areas, and that #us, in the long run, the species re- programme, comprising 35,350 person 75 % of the paired sites were faithfully invades. Management is addressing the days of labour. However, there was no placed within a matching cluster. #is symptoms rather than the cause. scienti!c investigation of the causes of suggests that overall plant species com- the Euryops invasion, nor of how the position is similar between the two, We recently examined the case of inv- broader population viewed or used it. and the composition of groupings in asion by an indigenous perennial shrub, the cluster analysis re"ected underlying Euryops !oribundus NEBR, in the #rough a household survey, we found abiotic site characteristics rather than inland mountains of the Eastern Cape that most households interviewed used di$erential land use pressure. province, South Africa. #is mountai- Euryops as a source of biomass fuel for nous area is covered largely by semi- cooking, with most households colle- #e situation regarding the occurrence, arid, sub-montane grasslands. A few cting it daily or every second day. A use and management of Euryops at the trees and shrubs can be found in valley few households also used it as packing site is clearly complex, with contrasting bottoms, but most were removed by lo- to build livestock enclosures, and alm- needs and understandings. Local hou- cal communities long ago for fuelwood ost none used it for medicinal purposes. seholds clearly make extensive use of it and fencing poles. #e species has a Many stressed that without Euryops as a resource, and are highly dependent wide distribution, but is usually relat- they would have to purchase para%n upon it as their primary source of fuel. ively sparse and con!ned to rocky out- for cooking fuel, which was expensive Its removal therefore represents a crops. However, in the Macubeni area and not always available. Hence, their potential cause of hardship and reduc- it has invaded large tracts of land, and energy security was vested in being tion in energy security. Another bene!t is believed to be promoted by heavy gra- able to collect Euryops within an acces- of its presence seems to be the higher zing pressure by domestic livestock. In sible distance. plant species richness associated with protected outcrops it grows up to 2.5 patches of Euryops relative to the sur- mt tall, but in open environments it is #e results of an ecological survey rounding grasslands. usually less than 0.75 metre tall. comparing sites, with and without Euryops re"ected certain di$erences We suggest this is because the shrub #e Macubeni area is one of the poor- in habitat variables. Overall, there was o$ers a physical refuge to certain spe- est in South Africa. It consists of 14 no statistical di$erence in the propor- cies. #is is supported by the lower- villages with approximately 1,700 hou- tion of bare ground or total plant cover grazing pressure in the invaded areas seholds. Livestock stocking rates in the between invaded and paired non-inva- (as indexed by the lower frequency of Macubeni area are over three times ded areas. However, there was signi!- livestock dung). #us, on the one hand what is recommended by government cantly less grass cover, but a higher forb there is widespread soil erosion and extension o%cers. #e signi!cant signs cover, in invaded sites. Interestingly, invasion by Euryops, which prompted of gully and sheet erosion obvious thr- however, was the fact that there was a external authorities to take action. As oughout the area are blamed on the signi!cantly higher plant species rich- livestock grazing regimes were impli- high stocking rates (although the rela- ness in the invaded sites than the cated (although never examined) in

EWTTGPVEQPUGTXCVKQP^ Pallavi Baasri

both of these negative manifestations deprive most households of their pri- ing and its presumed attendant ill- the reasoning of authorities was either mary source of biomass fuel. Interest- e$ects of soil erosion and reduction in reduce the livestock numbers or incre- ingly, the collection of biomass fuel is plant species richness. ase the area available for grazing. Local the purview of women, who typically * Charlie Shackleton is Professor of Environmental owners of livestock argued for the latter, lack a voice in community meetings Science, Rhodes University, Grahamstown, South proposing that funds be provided to ma- and household a$airs. It will also open Africa. Mail at [email protected] nually remove Euryops. If successful up the invaded areas to increased graz- * James Gambiza is a Senior Lecturer in Environ- this would bene!t households who own ing again, and potential loss of the ref- mental Science, Rhodes University, Grahamnstown, livestock and also provide some temp- uge sites for several plant species. How- South Africa. orary employment to poorer househo- ever, if the excessive grazing was the Further reading: Shackleton CM & J Gambiza. lds. However, livestock owning house- cause of the invasion in the !rst place, 2008. Social and ecological trade-o%s in combating holds are in the minority, and are gen- what will prevent the shrub from rein- land degradation: #e case of invasion of a woody erally more wealthy than average. vading in time? #e bottom line is that shrub (Euryops !oribundus) at Macubeni, South Africa. Land Degradation & Development 19: Moreover, livestock ownership is the until a thorough ecological study is und- 464-46 domain of men, and in a patriarchal ertaken to understand the causes and society they have greater power in com- consequences of the invasion, any inter- munity meetings and household a$airs. ventions and relief e$orts are likely to On the other hand, our results have be temporary, whilst removing the res- show that the removal of Euryops will pite the invasion o$ers to heavy graz-

^EWTTGPVEQPUGTXCVKQP URQVNKIJV^,QJP8QNKP #PCVQO[QHCP+PXCFGT

7KLVFOLPELQJIHUQKDV After an invasive species has been stud- Several of these !eld and controlled SODVWLFVH[OLYHVLQFURZG ied for a time, a Gestalt of that species studies were linked with landscape- HGFRPPXQHVDQGOLNHVLW usually begins to emerge. Unfortun- scale studies to develop a spatial model ZHW6WUDQJHO\LWVQRWWKHVH ately, this has been slow to develop of the fern’s potential spread across its DEHUUDQWTXLUNVEXWLWVVHF in the case of L. microphyllum. introduced environment. Finally, cross- UHWXQGHUJURXQGOLIHWKDW continental controlled and common PDNHVLWDJRRGLQYDGHU After more than a decade of study, the garden studies were carried out to com- reasons for its success as an invader pare the growth of the fern in its native In the continental United States, the only now begin to become apparent. versus its introduced environment. We Florida Everglades ranks among the To truly understand why an invasive learned much from our studies of L.mic- top locations in regard to the number plant is successful often requires exam- rophyllum’s reproductive biology. #e and coverage of introduced invasive ining the species across a range of scales fern is homosporous-it produces bise- species. Among Florida’s non-indigen- and in both its native and introduced xual gametophytes and, consequently, ous invasive "ora, a relatively recently habitats. #is has been the strategy my it can reproduce by three di$erent repr- introduced species, Lygodium microphy- colleagues and I have used to discover oductive strategies: intragametophytic llum, also known as Old World climb- why L. microphyllum is such a success- sel!ng, intergametophytic sel!ng and ing fern, is quickly becoming one of its ful invader in its de novo environment. outcrossing. Intragametophytic sel!ng most widespread. L. microphyllum !rst We began by studying its reprodution, allows for long distance dispersal beca- drew attention for escaping cultivation including its mode of reproduction, use it only requires one gametophyte to and spreading into natural lands in the the seasonality of sporulation and its establish new colonies, since sporelings late 1960s. However, little was done spore production. Our subsequent stu- (i.e., young plants) result from the un- with this observation until the late dies examined the fern’s community ion of an egg and sperm on the same 1990s, when active scienti!c research ecology and its growth, both in situ gametophyte. #e second and third on its ecology and management, inclu- and under controlled conditions, with strategies require two spores to land ding biological, chemical, and mechan- various environmental treatments, inc- close together and to germinate into ical control activities began in earnest. luding the in"uence of di$erent light gametophytes, such that a sperm can and di$erent hydrological environments swim from one gametophyte to the L. microphyllum, a vine-like fern native on its growth. to the pantropics of the Old World, is typically considered a benign constitu- ent of its native plant communities.

However, in its Florida introduced hab- Arjun Shankar itat it can develop a near monoculture, smothering the native understory under a mat of vegetation that can be thicker than 1 metre. #e fern also climbs into the native overstory, eventually shading and killing the canopy trees and resulting in their collapse. In some cases, the fronds act as a ‘!re ladder,’ allowing !re into the canopy and resulting in the death of the host trees.

EWTTGPVEQPUGTXCVKQP^ other. In the case of intergametophytic from low to high irradiances. Later ence of aggressive control measures, sel!ng, the two gametophytes are from evidence in controlled studies showed this model predicted that the coverage the same parent plant, while with outc- that small plants of L. microphyllum of L. microphyllum could exceed the rossing the two gametophytes are from have the same relative growth rate after coverage of the top !ve invasive spe- di$erent parent plants. Typically, homo- 3 months whether growing in 20, 50 cies in Florida by 2014. Fortunately, sporous ferns are conservative in their or 70% full sun light. #e ability of the aggressive biological, chemical and reproductive strategy, in that they only fern to maintain high growth under mechanical control for this species has reproduce by one of the three modes. di$erent light environments appears to been ongoing. We found that this is not the case for be related to its ability to allocate carbon L. microphyllum, which we determined to stems in a highly plastic and favora- #ese early studies highlighted some was able to reproduce by all three mat- ble manner. For instance, in the high- of the attributes that help explain L. ing strategies. However, we also discov- est light environment, the plants grow microphyllum’s ability to be invasive in ered an interesting invasive twist to its on average 2.9 m for every gram of car- its introduced environment. #e same reproductive strategy. bon invested, while in the lowest light studies, combined with intensive moni- conditions the plants grew 4.2 m per toring e$orts, allowed us to develop a When a gametophyte !rst germinates gram of carbon. #ese !ndings were spatially explicit predictive model that from a spore, it is almost always female supported by 2 years of !eld observa- assisted in sounding the alarm, partic- and this female produces a pheromone tions where under high light condit- ularly to policy makers, since most land that makes all younger nearby gameot- ions the height of the actual climbing managers had already understood the phytes to become male, thus assuring mat (i.e., not individual stems) increased dire consequences that ignoring this outcrossing. On the other hand, if aft- 1.43 m per year on host canopy trees. species would have on natural lands. er a few weeks there are no nearby spores or gametophytes, the female will We were able to combine the attributes However, this series of studies was not become bisexual by producing male or- of the fern from our studies of its repro- su%cient to fully understand why this gans thus assuring fertilisation. Collec- duction biology and ecology with a seri- species is so successful in its new envir- tively, these highly plastic reproductive es of aerial transects to develop a spatial onment, while being apparently so be- strategies help explain the fern’s long model predicting the future spread of nign in its native range. Moreover, to distance dispersal. We followed this this highly invasive fern across the land- optimise management of this species, initial work with studies related to the scape. In 1978, a survey of known further studies were needed to provide fern’s seasonal spore patterns, spore pr- individual L. microphyllum sites was additional information that could be oduction and community ecology. In published. In 1993, the South Florida used in both biological control and land its introduced environment, we found Water Management District began management e$orts. that dense sites of L. microphyllum prod- conducting aerial surveys every 2 years uce spores year round, with a peak pro- to monitor invasive species, including Interestingly, from our earlier control- duction in the wet season. We estimated L. microphyllum, locations across the led studies under di$erent light condi- a density of 15,000 spores per cm2 of Southern Florida region. Combined tions, we found that L. microphyllum fertile leaf area, resulting in approxima- with our earlier data, we were able to allocated 48% of its carbon to below- tely three billion spores present at each construct a cellular automaton lands- ground tissues, while a native vine in invaded site at any given time. Our cape model by calibrating the model the same study averaged only 27%. community-level studies showed that from the 1978 survey data stepped thr- #e latter is a typical investment for the presence of the fern coincided with ough to 1993. #en we validated the a vine belowground, given that vines a wet but not permanently inundated model independently from 1993 to 1999 characteristically maximise their allo- environment, and the coverage of the using the aerial data. Finally, by initia- cation to above ground tissues in order fern was greatest in a low-light under- lizing our model with the 1999 aerial to reach greater heights to optimise story environment, which likely facili- survey data, we predicted the spread of light interception. L. microphyllum, on tates its early establishment and growth. the fern to 2014, showing that 37% of the other hand, is able to grow to great Anecdotally, L. microphyllum can be the 40,000 km2-grid cells covering heights, but it does it with relatively found in the various light conditions Southern Florida would have L. micr- little investment in carbon. It was this that exist in Florida’s native ecosystems, ophyllum present by 2014. In the abs- observation that !rst led us to consider

^EWTTGPVEQPUGTXCVKQP that, perhaps, L. microphyllum is such othesis that the invasiveness of L. mic- a successful invasive because it may be rophyllum in Florida is in part mediated released from its natural belowground by release from soil-borne enemies, and enemies. #is would allow the plant to given the di$erent response of the Sou- allocate substantially to belowground theastern Queensland population in tissues, which may confer a competit- Australia as compared to the other pop- ive advantage in the low nutrient envi- ulations, a region-speci!c response ronment of southern Florida. We tes- may be occurring. ted this hypothesis through a series of coordinated control and !eld common In both its native and introduced garden studies in its introduced range environment, L. microphyllum is in Florida as well as in its native range found in wetland environments, in Australia. We examined the fern’s growth across soil treatments, including soil sterilization to eliminate below ground natural enemies, and nutrient ame- ndments to examine the possible intera- ction of soil nutrient availability. In addition, in the native range, we used three di$- erent fern source populations; one from Florida, one fromthe study location in Southeastern Queensland, Aust- ralia, and the third from northeastern Queensland, Australia. #is third source is the reputed original location of the plants introduced into Florida. All populations tended to have comparati- vely poor growth in unaltered soil, but growth for all was stimulated by nutrient amendment and sterilisation. #e overall e$ect of sterilisation, however, was muted under high nutrient conditions, except for the population orig- Kalyani Ganapathy inating from the same region as the soil used in Australia. Regardless of nutrient treatment, ferns in this population grew signi!cantly faster in sterilized than non-sterilized soil.

So what does this mean? It appears that overall these results supported our hyp- innae (i.e., leaf) area and photosynthe- costs in tissue construction, thereby ga- but appears to be able to tolerate a ra- sis: in other words, morphological and ining the ability to grow rapidly across nge of hydrological conditions. #ere- physiological determinants of growth, gradients in light and hydrology. On the fore, we conducted another study to respectively. other hand, in its native range, this abi- examine L. microphyllum growth resp- lity to grow across environmental grad- onse to three hydrological treatments; From these numerous studies condu- ients and reproductive output may be "ood, drought and !eld capacity. Field cted at various scales under di$erent constrained by natural enemies. Our capacity and drought showed no di$e- environmental conditions, as well as cross-continental comparisons appear rences in growth, while "ooded plants from comparisons between introduced to support our hypothesis that release had signi!cantly slower growth. How- and native habitats, we eventually dev- from natural enemies belowground may ever, it should be noted that, even after eloped an understanding of why L. mi- also help explain the success of the fern more than 2 months of continuous crohpyllum is such a successful invader, in its introduced environment and, pro- inundation, the "ooded ferns demon- while at the same time a relatively ben- vocatively, given the di$erent source strated positive relative growth rate. ign presence in its native environment. population responses, it appears that In essence, L. microhpyllum possesses a regional-scale version of the enemy #is apparent hydrological plasticity is several life-history characteristics that release hypothesis might play a role in likely another contributing factor to the may enhance its competitive ability in L. microphyllum’s invasive success. fern’s widespread establishment across Florida, including plastic reproductive a range of plant communities within strategies, and proli!c and continuous Our !ndings demonstrate the impor- the greater Everglades ecosystem. #e spore production. #is fern appears to tance of a biogeographical approach fern’s growth response to di$erences in optimise its morphological and physio- to invasive species studies and have hydrological conditions was largely exp- ological characteristics to maximise ph- implications for the identi!cation of lained by changes in its speci!c otosynthetic area and minimise carbon potential biocontrol agents. Moreover, the numerous studies at di$erent scales in the fern’s introduced environment allowed us to make speci!c management recommendations, provided clues to its invasiveness that could then be corroborated by comparative studies of its native versus introduced ranges, and allowed us to develop a landscape-level model that could inform scientists, land managers, policy makers and the public, of the imminent danger of this particular invasive plant.

* John Volin is a Professor of plant physiological ecology and Head, Department of Natural Resourc- es and the Environment at the University of Connecticut, Storrs, CT, USA. Mail at john. [email protected] Arjun Shankar

^EWTTGPVEQPUGTXCVKQP TGUGCTEJKPVTCPUNCVKQP

Adult male Tonkean Macaque, Indonasia Erin P Riley

&XOWXUH &RQVHUYDWLRQ * Hari Sridhar 6RFLDOWDERRVPLJKWKHOSSURWHFWWKH7RQNHDQ0DFDTXH

Folklore about the Tonkean Macaque and related to humans; for the same species in another area. (Macaca tonkeana) might be the reason Macaques should be treated well Moreover, people’s beliefs are not !xed behind an indigenous group in Indon- even when they raid crops because oth- and might change in response to exter- esia tolerating this crop-raiding species, erwise they will do much worse things nal in"uences. For example, even amo- reports a new study in the journal Oryx. Macaques act as guardians of Lin- ng the To Lindu, another taboo against du adat or customary law. the felling of strangler !gs is slowly Erin P Riley, a primatologist at the vanishing seemingly in response to the San Diego state university, conducted #ese biological, cultural and ecologi- rise of Christianity among its people. semi-structured interviews among the cal links to the Tonkean Macaque en- Given the tenuous nature of cultural To Lindu, an ethnic group indigenous visioned by the To Lindu has resulted reasons for conservation, it is therefore to highlands in Lore Lindu National in a taboo that prevents them from har- important that a suite of values, inclu- Park in Indonesia to understand how ming this crop-raiding species. Riley, ding ecological and economic bene!ts these people conceptualize the Tonkean uses this case study, to highlight the are used in justifying the conservation Macaque, a species which frequently importance of including traditional of a particular species. raids their crops. #rough a qualitative knowledge and beliefs in conservation Riley EP. 2010. #e importance of human– analysis of the data, she identi!ed three e$orts but also adds the caveat that macaque folklore for conservation in Lore Lindu main themes which characterized the cultural reasons for conservation are National Park, Sulawesi, Indonesia. Oryx 44(2): 235–240. To Lindu’s folklore about the macaques. probably context-speci!c and might Macaques were biologically similar not apply for a di$erent species or even

EWTTGPVEQPUGTXCVKQP^ -RLQLQJWKH'RWV been investigated. #is paper high- can provide perspective on long-term Hari Sridhar lights two particularly important uses trends in species occurrence, and in * of network building in the context of speci!c cases can allow us to assess (FRORJLFDOQHWZRUNVPLJKWEHWKHQH[W conservation: rates of population change. However, ELJWRROLQFRQVHUYDWLRQUHVHDUFK there are inherent biases in using this To identify and prioritise for conse- kind of data, such as no records of Conservation research has traditionally rvation, species whose extinction will species absence, changes in sampling focused on understanding how human- have strong secondary e$ects on other e$ort, spatial coverage, collection induced disturbances such as pollution members of the community. method or species focus that need to and hunting directly a$ect wild species, To understand what features of com- be accounted for before conclusions leading to their extinctions. Little is munities make them vulnerable or can be drawn. known about how these extinctions mi- resilient to disturbance. For example, ght in turn in"uence other species liv- it has been shown in numerous studies Tobbias Jeppson and colleagues at the ing in the area. One would guess that that the greater the number of ties bet- Swedish University of Agricultural these in"uences will be important ween species in a community, the less Sciences examined over 42,000 histor- because species are connected to other susceptible it is to disturbance. ical records of 108 species of longhorn species in myriad ways - as food, as beetles in Sweden collected between predators, as competitors for the same In spite of a great deal of research into 1908-2000 in order to determine if resource and as partners in mutually the impacts of humans on species and changes in species range coincided bene!cial relationships. Ulrich Brose, biodiversity over the last few decades, with changes in population abundance in this conceptual paper, argues that global extinction rates are currently over time. #ey also factored rarity of visualizing species as nodes in a net- at an all-time high. #is paper makes species into this analysis; for instance, work might help us understand these the case that this is due to a lack of they predicted that rare species would secondary e$ects of species extinctions. attention to species interactions and decline in range if they declined in that the next big step in conservation abundance. Take for example a simple food chain research will be to understand these involving an eagle, a snake and a frog. interactions using ecological networks. #e results showed that a number of species changed in abundance over #e snake feeds on the frog and in turn Brose U. 2010. Improving nature conservancy is fed on by the eagle. Now suppose strategies by ecological network theory. Basic and time, with most species exhibiting these snakes are hunted for their skin Applied Ecology 11(1): p. 1-5. increasing or stable trends while a few species showed declining trends in and over time become extinct, what * Hari Sridhar is a PhD student at the Centre for might happen to the eagles and the Ecological Sciences, Indian Institute of Science, population sizes. frogs? What might also happen to the Bangalore, India. Mail at [email protected] insects which the frogs eat and the Changes in species range did not other creatures that the eagles eat? re"ect changes in population size, /HVVRQVIURP+LVWRU\ and several species showed con"icting Building ecological networks of these relationships will help us predict the * R Nandini local and global trends. Rare species answers to these questions. with increasing populations showed &DQKLVWRULFDOUHFRUGVEHXVHGWRGH range expansions (unlike common spe- WHUPLQHSRSXODWLRQVL]HVDQGVSUHDG" Ecological networks are representa- cies), and rare species with decreasing tions of the pair wise relationships populations did not have larger range between species in an area. While contractions. #e authors suggest that initially, these networks were almost merely using range of species in threat entirely used in the context of food assessments might not su%ce, and webs such as in the example describe suggest using population sizes as well. above, more recently, other kinds of Jeppsson T, A Lindhe, U Gärdenfors & P Forslund. relationships such as competition and Historical records from museums 2010. #e use of historical collections to estimate positive interactions (for e.g. between specimens, reports, and !eld notes are population trends: A case study using Swedish long- a valuable source of information, and horn beetles (Coleoptera: Cerambycidae). Biological plants and their pollinators) have also Conservation 143: 1940 - 1950.

^EWTTGPVEQPUGTXCVKQP Arjun Shankar

5HPRYLQJ5DWVZLWK &DUH * R Nandini (UDGLFDWLRQRILQYDVLYHVVSHFLHVLQYRO deer mice, and care was taken not to and raptors were released one year after YHVPRQLWRULQJRIV\PSDWULFVSHFLHV eradicate this species. Before air-drop- application, and numbers are now seen ping pellets, speci!c species, like deer- to be similar to pre-application levels. Invasive species cause much damage to mice and raptors, that were thought to Following successful eradication of native biota, and eradicating these inv- be potentially at risk from the poison black rats from the island, positive ef- asives is often a di%cult time-consum- were captured, and a certain part of the fects were seen on murrulets and other ing and expensive process that involves local population was held in captivity. seabirds, including reduced predation careful planning and monitoring of Several environmental variables (soil, on eggs and sightings of a one addi- sympatric species. Gregg Howald of ocean samples) and animal popula- tional species of seabird. #e authors Island Conservation, Canada, and tions, including the target species, were stress the importance of holding colleagues at the University of Califor- monitored closely before and after the captive populations of natives species nia, Santa Cruz, eradicated black rats application of the poison. Rats were during large-scale eradication e$orts. completely eradicated by the procedure (Rattus rattus) on Anacapa island, o$ Howald G, Donlan CJ , Faulkner KR, Gellerman the coast of California, while simulta- and monitoring in the year found no SOH, Croll DA and Tershy BR. 2009. Eradication neously monitoring the impact of these more rats. of black rats Rattus rattus from Anacapa Island. Oryx 44(1): 30–40. e$orts on native fauna between 2001 However, while most other native and 2008. species were not adversely a$ected, the * R Nandini is a Research Associate at the National poison decimated populations of deer- Institute of Advanced Studies, Indian Institute of mice, raptors and small birds. Rufus- Science campus, Bangalore 560012. Mail at Pellets containing the poison Brodifa- [email protected] coum were air-dropped during the dry crowned sparrows were most a$ected, and were not sighted by the authors season, in a staggered fashion, between 6QEQPVTKDWVGCUWOOCT[QHCTGUG 2001-2002, to cover Anacapa Island. even 6-7 years after application. #e CTEJCTVKENGNQIQPVQQWTYGDUKVG YYYEWTTGPVEQPUGTXCVKQPQTI #e island has a native population of captive-held populations of deermice

EWTTGPVEQPUGTXCVKQP^ DQQMHTQOVJGCVVKE^5CTVCL5)JWOCP 6JG6JKPMKPI(GGNKPI#PKOCN

‘#e Expression of the Emotions in Man notes from observations of the insane, and Animals’, !rst published in 1872, and notes on the expression of emotions followed in the wake of ‘#e Origin in various races of human beings. #e of Species’ and ‘#e Descent of Man’. book thus brings together vast amounts Although an important landmark in of evidence from diverse !elds like phy- early behavioural studies, it was prob- siology, psychology, psychiatry, the arts ably overshadowed by Darwin’s earlier and animal behaviour. As is character- works of great importance and is thus istic of Darwin, there are no hand-wav- not as well known as his other writings. ing arguments or enthusiastic, but unwarranted, interpretations; instead he 6JGDGJCXKQWTUQHCPKOCNU #is book is not, as is sometimes made conducts a patient appraisal of the avai- CTGGCUKN[UGGPCPFYKFGN[ out to be, an explicitly comparative lable evidence and puts forward argu- CEMPQYNGFIGFDWVFQCPKO study of emotions in man and animals ments supported by extremely insight- CNUHGGN!+PCDQQMVJCVYCU to establish the continuity of emotions. ful observations replete with detailed OWEJCJGCFQHKVUVKOG It is actually an investigation into the descriptions of behaviour. %JCTNGU&CTYKPKNNWUVTCVGU nature and origin of the expression of VJGRTQHWUKQPQHGOQVKQPU emotions. #e questions Darwin inte- What makes the book special, though, KPVJGCPKOCNMKPIFQO nded to answer were more on the lines is how e$ortlessly and without hesita- of how far particular movements of the tion Darwin bestows upon animals all features and gestures are really expres- that Descartes had denied them: feel- sive of certain states of the mind and ings, emotions, volition. #ere is thus why certain muscles, and not others, an important extension here of the doc- contract under the in"uence of certain trine of evolution of species, one that emotions. To this end he took an implies morphological, behavioural evolutionary approach, for he believed and mental continuity not just over that the creationist assumption of imm- evolutionary time as species evolve, but utability of species, adopted by most within the extant species as well.Alth- authors of the time, hindered a thorough not explicitly sketched out in the ough investigation into the causes of text, the psychological continuity eme- emotions. rges as we are led to closely examine the emotions and behaviour of animals Darwin presents six lines of evidence to and man. ‘#e Expression’ is thus a re- try and answer the questions he posed; markable treatise, far ahead of its time, Arjun Shankar of these, he gives most importance to and an immensely signi!cant forerun- the close observation of expression of ner to the development of !elds like several ‘passions’ in the ‘commoner’ comparative psychology, which were animals. #e other evidence stem from, eventually to give rise to disciplines like for reasons that he explains in the intro- animal cognition and cognitive ethol- duction to the book, the observation of ogy that today delve into animal minds. babies, impressions of observers about Charles Darwin. 1872. !e Expression of the the emotion best expressed by photo- Emotions in Man & Animals. London: John graphs of the face of an old man when Murray. certain muscles were galvanized, study * Sartaj S Ghuman is a PhD student at the National Institute of Advanced Studies, Bangalore, India. of emotions in paintings and sculpture, Mail at [email protected]

^EWTTGPVEQPUGTXCVKQP 5WDUETKDGPQY 6RXWK$VLD To subscribe online, visit our website Individual Rs. 200.00 ZZZFXUUHQWFRQVHUYDWLRQRUJ Annual subscription rates for Cur- Institutional Rs. 500.00 rent Conservation. Cheques or For queries, write to Hetal Hariya at demand drafts should be in favour $IULFD$VLD/DWLQ$PHULFD KHWDO#FXUUHQWFRQVHUYDWLRQRUJ of 'DNVKLQ)RXQGDWLRQ Individual US$ 10.00 Dakshin Foundation, Institutional US$ 25.00 C 305, Samriddhi Gardenia, $XVWUDOLD(XURSH-DSDQ 88/3, Byatarayanapura, 1RUWK$PHULFD Near Sahakara Nagar A Block, Individual US$ 25.00 Bangalore 560092, India Institutional US$ 50.00 Kalyani Ganapathy