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Plant invasions: human perception, ecological impacts and management



This book contains 27 chapters that cover topics on: human perception and role in biological invasions; biology, ecology and distribution of invasive species; invasibility of habitats and impacts of invasive species; and control and management.
Edited by Barbara Tokarska-Guzik, John H. Brock, Giuseppe
Brundu, Lois Child, Curtis C. Daehler and Petr Pyšek
Backhuys Publishers, Leiden, 2008
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ISBN 978-3-8236-1528-6
ISBN 978-90-5782-201-8
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Preface ix
Index of main taxa xiii
Section 1 – Human perception and role in biological invasions 1
Invasive plant problems in the Hawaiian Islands and beyond:
insights from history and psychology 3
Curtis C. Daehler
Forestry and horticulture as pathways of plant invasions: a database of
alien woody plants in the Czech Republic 21
Martin Křivánek and Petr Pyšek
Assessing the risks to Mediterranean islands ecosystems from alien plant
introductions 39
Philip E. Hulme, Giuseppe Brundu, Ignazio Camarda, Panos Dalias, Phil
Lambdon, Francisco Lloret, Frederic Medail, Eva Moragues, Carey Suehs,
Anna Traveset, Andreas Troumbis and Montserrat Vilà
Balsams on the offensive: the role of planting in the invasion of Impatiens
species 57
Wojciech Adamowski
Section 2 – Biology, ecology and distribution of invasive species 71
Humulus japonicus, an emerging invader in Hungary 73
Lajos Balogh and István Dancza
Ecology and management of Alhagi maurorum in a pine-oak forest in
north-central Arizona, USA 93
John H. Brock
Solidago graminifolia in Poland: spread and habitat preferences 101
Zygmunt Dajdok and Arkadiusz Nowak
Dispersal of invasive Pinus strobus in sandstone areas of the Czech
Republic 117
Věra Hadincová, Zuzana Münzbergová, Jan Wild, Ludvík Šajtar and Jana
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Genotypic and phenotypic variation in a Fallopia × bohemica population
in north-eastern France 133
Annik Schnitzler, John Bailey and Celia N. Hansen
Modelling the spatial spread of Fallopia japonica on a local scale in the
United Kingdom 145
James M.D. Smith, John P. Ward, Lois E. Child and Markus R. Owen
Invasion of Impatiens glandulifera in the surroundings of the Babia Góra
National Park (Western Carpathians, Poland) 161
Aldona K. Uziębło
Section 3 – Invasibility of habitats and impacts of invasive species 169
Regional scale assessment of alien plant invasions: a case study for the
Silesian Upland (southern Poland) 171
Barbara Tokarska-Guzik, Alina Urbisz, Andrzej Urbisz, Beata Węgrzynek,
Teresa Nowak and Andrzej Pasierbiński
Communities with Bunias orientalis in human-made habitats of the Silesian
Upland (southern Poland) 189
Wojciech J. Bąba and Agnieszka N. Kompała-Bąba
Unsaturated guilds, unexploited resources and plant invasion: a case study
of floodplain vegetation in the Carpathian Basin 207
Csaba Tóth and Zoltán Botta-Dukát
Soil seed banks associated with two invasive species, Gunnera tinctoria
and Heracleum mantegazzianum 217
Margherita Gioria and Bruce Osborne
Patterns of native and alien plant species occurrence on coastal dunes in
Central Italy 235
Alicia T.R. Acosta, M. Laura Carranza, Luciano Di Martino, Annarita
Frattaroli, C. Francesca Izzi and Angela Stanisci
Soil microbial activity in dune ecosystems in Portugal invaded by Acacia
longifolia 249
Elizabete Marchante, Annelise Kjøller, Sten Struwe and Helena Freitas
Competitive balance between the alien invasive Acacia longifolia and
native Mediterranean species 261
Christiane Werner, Ralf Peperkorn, Cristina Máguas and Wolfram Beyschlag
vi Contents
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Performance of Imperata cylindrica in relation to light availability on soils
from the tropical forest-savannah boundary in central Cameroon 277
Lindsey Norgrove
Effects of Rosa rugosa invasion in different coastal dune vegetation types 289
Maike Isermann
The neophyte flora of North Tyrol (Austria): insights into an inner Alpine
region 307
Konrad Pagitz
Alien flora on walls in southern and western Moravia (Czech Republic) 317
Deana Simonová
Gammarid (Crustacea: Amphipoda) herbivory on native and alien fresh-
water macrophytes 333
Gabrielle Thiébaut and Pierre Gierlinski
Section 4 – Control and management 341
A review on the potential for the biological control of the invasive weed,
Impatiens glandulifera in Europe 343
Robert A. Tanner
Strategies for use of pathogens in weed biological control: some lessons
from pathogens in natural and agroecosystems 355
Timothy L. Widmer and Min B. Rayamajhi
Determination and management of alien plant impacts on biodiversity:
examples from New South Wales, Australia 369
Paul O. Downey
Protecting biodiversity by managing alien plants in national parks:
perspectives from South Africa and Australia 387
Llewellyn C. Foxcroft and Paul O. Downey
List of contributors 405
Index 413
Contents vii
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This volume continues the tradition of publishing key presentations from a series of
biennial International Conferences on the Ecology and Management of Alien Plant
Invasions (EMAPi) beginning in 1992 (see de Waal et al. 1994, Pyšek et al. 1995,
Brock et al. 1997, Starfinger et al. 1998, Brundu et al. 2001, Child et al. 2003). The
first conference, held in Loughborough, UK in 1992 brought together the latest
research and thinking on alien plant management within Europe. Since then, the
conference has widened its scope having been hosted in Kostelec nad Černými
Lesy, Czech Republic (1993); Tempe, Arizona, USA (1995); Berlin, Germany
(1997); La Maddalena, Sardinia, Italy (1999); Loughborough, UK (2001); Fort
Lauderdale, Florida, USA (2003) and most recently, in Katowice, Poland (2005).
The next conference is planned for Perth, Australia in 2007. The number of partic-
ipating countries and organisations has increased steadily over the years with 150
delegates from over 30 countries and five continents represented at the Katowice
conference. This is an indication of the world-wide importance of plant invasions
and the need for a global network to exchange research outcomes, ideas and best
management practices of invasive plants.
Plant invasions are, of course, only a fraction of the whole process of biological inva-
sions concerning marine, freshwater and terrestrial environments, including plants
and other living organisms. Another notably parallel conference series has been
organised in Europe by the German Working Group on Biological Invasions NEO-
BIOTA. This group aims to coordinate responses to the ever increasing problems
caused by the invasion of alien plants, animals, fungi and micro-organisms, focussing
mainly on Central Europe, with its first conference held in 2000 in Berlin, Germany
(Kowarik & Starfinger 2000, 2003, Kühn & Klotz 2004, Nentwig et al. 2005).
The effects of invasive alien species (IAS) are widespread and pose a significant
threat to global biodiversity. The European Union has recognised the proliferation
of invasive alien species as an emerging issue, funding the GIANT ALIEN project,
which focused on Heracleum mantegazzianum (Pyšek et al. 2007), and the EPI-
DEMIE project (Exotic Plant Invasions: Deleterious Effects on Mediterranean
Island Ecosystems) (Hulme et al. 2007) under the 5th Framework Programme in
2002–2005, as well as ongoing projects addressing biological invasions (ALARM
– Assessing Large Scale Risks for Biodiversity with Tested Methods; DAISIE –
Delivering Alien Invasive Species Inventories for Europe) under the 6th Framework
Programme. During the Environment December 2006 meeting (2773rd) the
Council of the European Union called upon the European Commission to assess
gaps in the current legal policy and economic framework for the prevention of intro-
duction and for the control and eradication of invasive alien species. Furthermore,
the Council invited the Commission, in cooperation with the member States, to pre-
pare an EU strategy and an effective early warning system, on the basis of the
Convention on Biological Diversity (CBD) Guiding Principles on Invasive Alien
Species. Since the 1992 CBD, this is probably the strongest legal European com-
mitment to address invasive species with legislation and regulatory tools.
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The United Nations’ 2002 Convention on Biological Diversity (CBD) has recog-
nized an urgent need to address the impacts of IAS and has included ‘Trends in
invasive alien species’ with trial indicators to be developed and used for assessing
global progress towards the 2010 target of halting biodiversity loss. In this frame-
work, a pan European initiative, Streamlining Biodiversity Indicators by 2010
(SEBI 2010), was launched in 2004. One of the deliverables of this initiative will
be the editing of a list of the worst invasive alien species threatening biodiversity in
Europe. Some of the species that are present in the SEBI draft list, such as Ailanthus
altissima, Carpobrotus spp., Fallopia japonica are the prime subject of papers pre-
sented in this volume.
At an international level, the Global Invasive Species Programme (GISP) has
encouraged countries to recognize that they cannot solve problems connected with
biological invasions by working solely within their own administrative borders. By
their very definition, IAS are an international problem. Apart from their threat to
biodiversity and ecosystem services, invasive species have a significant socio-eco-
nomic impact. Developing countries are particularly vulnerable to the threats posed
by invasive species because their economies typically rely heavily on agriculture,
locally cultivated varieties, forestry and fishing. Moreover, within these countries it
is generally the rural communities that are most at risk, as their livelihoods are
almost solely based on these economic sectors, while the poorest people may be
dependent on local biodiversity for food, fuel and construction material (GISP
The number of meetings, workshops and scientific publications on biological inva-
sions is steadily increasing at a global level, seemingly in relationship with the
dynamics of the process, and the field has been receiving increasing attention
(Pyšek et al. 2006). Actions are now in progress, including amelioration of the leg-
islation, even in those countries where, until recently, the presence of invasive alien
plants was regarded as a botanical curiosity. There is now increasingly consolidat-
ed knowledge available about best practices for prevention, control, monitoring,
risk assessment, and – in limited cases – eradication of IAS. Finally, biological inva-
sions provide an exciting laboratory for ecological studies, e.g. as in the case of geo-
graphical or biogeographical islands (Daehler 2006) or concerning the relationships
between species invasiveness and habitat invasibility (Richardson and Pyšek 2006).
Nevertheless, in total conflict both with the general increasing background knowl-
edge and evidence of actual impacts, species continue to be introduced in many
regions of the world without any comprehensive risk assessment. Introductions con-
tinue to be made for diverse purposes e.g. as ornamentals in the Mediterranean, for
erosion control in China and Asia and to protect from desertification and provide
fodder, charcoal and fuel wood in the dry zones of Africa. Furthermore, in many
countries, a national legislation framework is lacking showing that continued rais-
ing of awareness and education are needed in addition to scientific study.
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This volume aims to contribute to this growing field, exploring human perceptions
of plant invasions and the role of humans in the invasion process from different per-
spectives and geographical areas. It also covers case studies of the biology and ecol-
ogy of invasive species, mechanisms of invasion and ecological impacts, while
offering solutions through a variety of control and management techniques.
The terminology associated with plant invasions is diverse and sometimes confus-
ing. As in the previous volumes, we have attempted to standardize terminology used
in this book following suggestions by Richardson et al. (2000) and Pyšek et al.
We thank all contributors to this volume, the participants of the 8th EMAPi confer-
ence at the University of Silesia, Katowice, Poland, and the sixty-seven reviewers
for their valuable help in reviewing the papers. We are grateful to Wil Peters and
Michael Ruijsenaars of Backhuys Publishers for their advice during the editing of
the book.
We particularly thank the following institutions for their assistance and support:
Faculty of Biology and Environmental Protection, University of Silesia; Institute of
Botany, Jagiellonian University; Władysław Szafer Institute of Botany, Polish
Academy of Science; Białowieża Geobotanical Station, Warsaw University; Odra
Project, WWF Poland and The National Fish and Wildlife Foundation, located in
Washington, DC, for providing the funding for a working meeting held in August
2004 in preparation for the 2005 Katowice conference.
Finally, logistic help from the following people during the organization of the
conference is greatly acknowledged: Wojciech Adamowski, Beata Babczyńska-
Sendek, Alicja Barć, Agnieszka Błońska, Katarzyna Bzdęga, Barbara Fojcik, Anna
Gawron, Ewa Gucwa-Przepióra, Monika Jędrzejczyk-Korycińska, Agnieszka
Kompała-Bąba, Zbigniew Kuc, Zbigniew Mirek, Teresa Nowak, Maria Palowska,
Andrzej Pasierbiński, Wojciech Paul, Adam Rostański, Krzysztof Rostański, Edyta
Sierka, Alina Urbisz, Beata Węgrzynek, Andrzej Woźnica, Gabriela Woźniak,
Adam Zając and Maria Zając.
Barbara Tokarska-Guzik, John H. Brock, Giuseppe Brundu, Lois Child,
Curtis C. Daehler and Petr Pyšek
Brock, J.H., Wade, M., Pyšek, P. and Green, D. (eds.) 1997. Plant invasions: Studies from North
America and Europe. Backhuys Publishers, Leiden, The Netherlands. [223 pp.]
Brundu, G., Brock, J.H., Camarda, I., Child, L. and Wade, M. (eds.) 2001. Plant invasions: Species
ecology and ecosystem management. Backhuys Publishers, Leiden, The Netherlands. [338 pp.]
Child, L.E., Brock, J.H., Brundu, G., Prach, K., Pyšek, P., Wade, P.M. and Williamson M. (eds.)
2003. Plant invasions: Ecological threats and management solutions. Backhuys Publishers,
Leiden, The Netherlands. [457 pp.]
Preface xi
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Council of the European Union, 2006. 2773rd Council Meeting Environment. Brussels, 18 December
2006. 16164/06 (Presse 349). Available at:
Daehler, C.C. 2006. Invasibility of tropical islands: partitioning the influence of isolation and
propagule pressure. Preslia 78: 389-404.
de Waal, L.C., Child, L.E., Wade, P.M. and Brock, J.H. (eds.) 1994. Ecology and management of
invasive riverside plants. John Wiley & Sons, Chichester. [217 pp.]
GISP, The Global Invasive Species Programme. 2007. Invasive species and poverty: Exploring the
links. [12 pp]. Available at:
Hulme, P.E., Brundu, G., Camarda, I., Dalias, P., Lambdon, P., Lloret F., Medail, F., Moragues, E.,
Suehs, C., Traveset, A., Troumbis, A. and Montserrat, V. 2007 [this volume] 39-56.
Kowarik, I. and Starfinger, U. (eds.) 2002. Biologische Invasionen – eine Herausforderung zum
Handeln? NEOBIOTA 1 [377 pp.]
Kowarik, I. and Starfinger, U. 2003. Introduction. In: Kowarik, I. and Starfinger, U. (eds) Biological
Invasions in Central Europe - a Challenge to Act? Biological Invasions 5: 279.
Kühn, I. and Klotz, S. 2004. Biological Invasions – challenges for science. NEOBIOTA 3 [154 pp.]
Nentwig, W., Bacher, S., Cock, M.J.W., Dietz, H., Gigon, A. and Wittenberg, R. (eds.) 2005.
Biological Invasions – from Ecology to Control. NEOBIOTA 6 [199 pp.]
Pyšek, P., Prach, K., Rejmánek, M. and Wade, P.M. (eds.) 1995. Plant invasions: General aspects
and special problems. SPB Academic Publ., Amsterdam. [263 pp.]
Pyšek, P., Cock, M.J.W., Nentwig, W. and Ravn, H.P. (eds.) 2007. Ecology and management of Giant
Hogweed (Heracleum mantegazzianum). CAB International, Wallingford. [324 pp]
Pyšek, P., Richardson, D.M. and Jarošík, V. 2006. Who cites who in the invasion zoo: insights from
an analysis of the most highly cited papers in invasion ecology. Preslia 78: 437-468.
Pyšek, P., Richardson, D.M., Rejmánek, M., Webster, G.L., Williamson, M. and Kirschner, J. 2004.
Alien plants in checklists and floras: towards better communication between taxonomists and
ecologists. Taxon 53: 131-143.
Richardson, D.M. and Pyšek, P. 2006. Plant invasions: Merging the concepts of species invasiveness
and community invasibility. Progress in Physical Geography 30: 409-431.
Richardson, D.M., Pyšek, P., Rejmánek, M., Barbour, M.G., Panetta, D. and West, C.J. 2000.
Naturalization and invasion of alien plants: concepts and definitions. Diversity and
Distributions 6: 93-107.
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mechanisms and human responses. Backhuys Publishers, Leiden, The Netherlands. [362 pp.]
WEB References
ALARM homepage:
DAISIE homepage:
EMAPI homepage:
EPIDEMIE homepage:
GIANT ALIEN homepage:
GISP homepage:
SEBI 2010 homepage:
NEOBIOTA homepage:
xii Preface
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... Humulus scandens est une plante introduite et utilisée en plantations ornementales, pour une croissance sur des treillis, des tonnelles ou des clôtures (Tournois, 1914 ;Chevalier, 1943 ;Balogh et Dancza, 2008). C'est donc une marchandise, principalement commercialisée sous forme de graines (akènes), puisque c'est une plante annuelle. ...
... En France, les zones au climat le plus favorable sont situées dans la partie sud du territoire, à basse altitude (e.g Sud-Ouest, vallée du Rhône et vallée de la Saône). (Balogh et Dancza, 2008, Fried et al., 2018. (Fried et al., 2018). ...
... Une étude dans l'aire de répartition naturelle a révélé une densité moyenne de 32,3 ± 37,0 individus / m² (Masuda et Washitani, 1990). En Europe, la période de floraison s'étend de juillet à septembre (Balogh et Dancza, 2008). Dans une enquête réalisée dans le sud de la France en 2013, les premières fleurs ont été observées le 23 août, et les premiers fruits matures ont été observés fin septembre. ...
... Changes of population sizes across time and space are entangled. For instance, space-for-time substitution has been applied in studies on plant succession after disturbance (Cooper, 1923;Crocker and Major, 1955) and the impact of biological invasions on native ecosystems (Fukami and Wardle, 2005), yet both have been heavily criticized because species spatial distribution and temporal dynamics are often governed by different ecological processes (Tokarska-Guzik et al., 2008). As a rule of thumb, the space-for-0304-3800/$ -see front matter © 2010 Elsevier B.V. All rights reserved. ...
Forecasting the temporal trend of a focal species, its range expansion or retraction, provides crucial information regarding population viability. To this end, we require the accumulation of temporal records which is evidently time consuming. Progress in spatial data capturing has enabled rapid and accurate assessment of species distribution across large scales. Therefore, it would be appealing to infer the temporal trends of populations from the spatial structure of their distributions. Based on a combination of models from the fields of range dynamics, occupancy scaling and spatial autocorrelation, here I present a model for forecasting the population trend solely from its spatial distribution. Numerical tests using cellular automata confirm a positive correlation, as inferred from the model, between the temporal change in species range sizes and the exponent of the power-law scaling pattern of occupancy. The model is thus recommended for rapid estimation of species range dynamics from a single snapshot of its current distribution. Further applications in biodiversity conservation could provide a swift risk assessment, especially, for endangered and invasive species.
Full-text available
The Japanese Rose (Rosa rugosa) is a perennial shrub belonging to the family Rosaceae. It was introduced in Europe from East Asia as an ornamental plant in the XIX century and it is now considered an invasive species especially in northern Europe, colonising in particular the Atlantic and Baltic coastal dune habitats and threatening local biodiversity. Nevertheless, little is known about its presence and invasion patterns in the Mediterranean area. In Italy, R. rugosa has been classified as naturalised and just a few observations have been recorded in dune habitats in the North Adriatic coast. Here, we review published data about R. rugosa in Europe and present preliminary data on the invasive pattern of R. rugosa on the North Adriatic coast. We surveyed the coastline in two locations (i.e., Brussa and Bibione, Italy) where we characterised the dimension and structure (i.e., number of ramets and stem height) of the R. rugosa populations and listed the associated floristic composition. No occurrence of R. rugosa was recorded in Bibione, probably due to the success of the restoration project carried out on that site. In contrast, several stands of R. rugosa were found in Brussa, where other alien species were also found (accounting for 15.28% of the sampled species). Given the strong invasiveness of R. rugosa, it is important to keep data on its distribution up-to-date and investigate its ecology and physiology to promote appropriate management strategies to control its spread and anticipate its future potential distribution.
Full-text available
During the first 25 years, EMAPi conferences were attended by 1280 participants from 77 countries in five continents and produced 1474 presentations, including 44 keynotes on a broad range of aspects of plant invasion ecology. The series was established in Loughborough, UK, in 1992 and with its 14th conference in Lisbon, Portugal in 2017 it has become the longest held series of regular meetings in plant invasion ecology with the number of participants in the last decade ranging between 150 and 250 per meeting. Of the 14 events so far, eight were held in Europe, three in North America and the remaining three in Australia, Africa and South America, respectively. The EMAPi series continues to be maintained by an informal board consisting of the organizers of previous meetings. Over time, there has been a shift in research focus from the ecology of species invasiveness and community invasibility, analyses of distribution and spread dynamics towards presentations dealing with management, control, risk assessment and impact. The latter topics, although well represented even at the beginning of the EMAPi conferences, increased their proportion among the total number of papers delivered, from about a quarter to more than half. Ten conferences yielded proceedings and up to 2008 these were published as books with Backhuys Publishers, followed by two issues in the journals Biological Invasions and NeoBiota. By forming a long-term meeting platform, addressing a broad range of topics, reflecting development in plant invasion ecology, achieving truly global geographical coverage and bringing together researchers and practitioners into close contact, EMAPi has become an excellent venue for initiating collaborations among invasion ecologists worldwide.
Full-text available
The number of alien plants escaping from cultivation into native ecosystems is increasing steadily. We provide an overview of the historical, contemporary and potential future roles of ornamental horticulture in plant invasions. We show that currently at least 75% and 93% of the global naturalised alien flora is grown in domestic and botanical gardens, respectively. Species grown in gardens also have a larger naturalised range than those that are not. After the Middle Ages, particularly in the 18th and 19th centuries, a global trade network in plants emerged. Since then, cultivated alien species also started to appear in the wild more frequently than non-cultivated aliens globally, particularly during the 19th century. Horticulture still plays a prominent role in current plant introduction, and the monetary value of live-plant imports in different parts of the world is steadily increasing. Historically, botanical gardens-an important component of horticulture-played a major role in displaying, cultivating and distributing new plant discoveries. While the role of botanical gardens in the horticultural supply chain has declined, they are still a significant link, with one-third of institutions involved in retail-plant sales and horticultural research. However, botanical gardens have also become more dependent on commercial nurseries as plant sources, particularly in North America. Plants selected for ornamental purposes are not a random selection of the global flora, and some of the plant characteristics promoted through horticulture, such as fast growth, also promote invasion. Efforts to breed non-invasive plant cultivars are still rare. Socio-economical, technological, and environmental changes will lead to novel patterns of plant introductions and invasion opportunities for the species that are already cultivated. We describe the role that horticulture could play in mediating these changes. We identify current research challenges, and call for more research efforts on the past and current role of horticulture in plant invasions. This is required to develop science-based regulatory frameworks to prevent further plant invasions.
Full-text available
An observational study was conducted to update the vascular wall flora of the world's oldest city of Varanasi, which spreads over an area of about 150 km 2 and situated on the bank of sacred Ganges River in Uttar Pradesh state of India. A total of 192 vascular plant species were recorded from the walls of city, of which 190 species were represented by angiosperms belonging to 147 genera and 51 families while only 2 species were represented by the pteridophytes belonging to 2 genera and 2 families. No any species of gymnosperms was recorded from the walls of Varanasi city. Asteraceae, Poaceae and Fabaceae were the dominant families of the vascular wall flora of Varanasi city. Analysis of wall flora with respect to life forms indicated the dominance of therophytes. The exotic plant species exceeds the number of native plant species on the walls of Varanasi city. Ficus benghalensis, Ficus racemosa, Ficus religiosa, Lindenbergia indica and Tridax procumbens were the most common vascular plant species observed on the walls of Varanasi city.
Full-text available
Premise of research. Invasive plants usually have growth and reproductive abilities that allow them to cope with new habitats and environments. The small balsam, Impatiens parviflora, is one of the most widespread annual invasive species in Europe. As no precise physiological assessment for this species has been performed, we compared physiological traits linked to growth performance in contrasting environments. Methodology. Plants were cultivated in growth chambers under four different treatments varying by light and water conditions. We assessed the impact of water stress and low light levels on traits related to plant growth, leaf physiology, photosynthesis, and water status. Pivotal results. Tolerance of low light level was reflected by several morphological and physiological characteristics. The number of leaves initiated was not affected by light condition, whereas specific leaf area increased for plants grown under low light. In addition, the chlorophyll fluorescence parameters revealed that low light did not affect the light-dependent reactions of photosynthesis. Although the net rate of photosynthesis was reduced, plant growth was not markedly affected. Our results thus suggest that I. parviflora generally copes well with shady conditions. The traits involved in efficiency of water use and water conservation indicated that I. parviflora is also highly tolerant to water stress. Although a reduction in plant growth and abscission of old leaves were observed after 4 wk of stress, I. parviflora demonstrated several mechanisms to maintain the light-dependent reactions of photosynthesis under water-stress conditions. Water use efficiency strongly increased in response to water stress, and plants adjusted their water potential to maintain their water supply. Conclusions. Impatiens parviflora shows physiological traits that allow plant growth under contrasting and stressful environments. These physiological traits may contribute to its invasive ability.
Full-text available
Three Anthoxanthum species are found in Poland: the native A. odoratum L. s. str. and A. alpinum Á. Löve & D. Löve, and the alien A. aristatum Boiss. Major problems within this genus concern: (1) population variation of the native A. odoratum, representing various phases of ecological expansion to anthropogenic habitats; (2) population variation of A. odoratum and A. alpinum along the altitudinal transect; and (3) variation between populations of A. aristatum colonizing new areas and habitats outside its natural range of distribution (chorological expansion). In this study, morphological and anatomical variation of the three Polish Anthoxanthum species was analysed in detail. The variation of A. odoratum and A. aristatum was analysed in respect of environmental differences: habitat types and soil parameters. In the Babia Góra massif, variability distribution along the altitudinal transect was analysed for two vicariants: A. odoratum and A. alpinum. A odoratum in this massif does not cross the upper forest limit (i.e. forest line), and lower montane populations are morphologically very similar to lowland populations. Morphological and anatomical differences were detected between populations of A. alpinum along the altitudinal transect in the Babia Góra massif, with distinct upper montane populations. Moreover, clear morphological differences were found between the two altitudinal vicariants. Lowland populations of A. odoratum are characterized by great morphological variation, only weakly correlated with the type of occupied habitat and the phase of ecological expansion. The detected morphological variation reflects only to a limited extent the environmental variation of occupied habitats, and is not significantly correlated with the phase of chorological expansion. Some soil parameters are significantly correlated with some morphological characters studied in all the Anthoxanthum species. The analysed anatomical features of stems and leaves show continuous variation in the three species.
The Giant Hogweed Heracleum mantegazzianum is a pernicious invasive species, with significant impact on human health due to its phytoxic sap. From its native area, the Caucasus, it has spread across Europe creating serious environmental and health problems. This book, the output of a three-year EU project involving 40 European experts, is an authoritative compendium of current knowledge on this amazing invasive plant and will facilitate improved management. It is an invaluable resource for both practitioner and student, and covers topics including taxonomy, genetics, reproduction, population ecology, and invasion dynamics. It also reviews the possibilities of mechanical, chemical and biological control.
All else being equal, more isolated islands should be more susceptible to invasion because their native species are derived from a smaller pool of colonists, and isolated islands may be missing key functional groups. Although some analyses seem to support this hypothesis, previous studies have not taken into account differences in the number of plant introductions made to different islands, which will affect invasibility estimates. Furthermore, previous studies have not assessed invasibility in terms of the rates at which introduced plant species attain different degrees invasion or naturalization. I compared the naturalization status of introduced plants on two pairs of Pacific island groups that are similar in most respects but that differ in their distances from a mainland. Then, to factor out differences in propagule pressure due to differing numbers of introductions, I compared the naturalization status only among shared introductions. In the fast comparison, Hawai'i (3700 km from a mainland) had three times more casual/weakly naturalized, naturalized and pest species than Taiwan (160 km from a mainland); however, roughly half (54%) of this difference can be attributed to a larger number of plant introductions to Hawai'i. In the second comparison, Fiji (2500 km from a mainland) did not differ in susceptibility to invasion in comparison to New Caledonia (1000 km from a mainland); the latter two island groups appear to have experienced roughly similar propagule pressure, and they have similar invasibility. The rate at which naturalized species have become pests is similar for Hawai'i and other island groups. The higher susceptibility of Hawai'i to invasion is related to more species entering the earliest stages in the invasion process (more casual and weakly naturalized species), and these higher numbers are then maintained in the naturalized and pest pools. The number of indigenous (not endemic) species was significantly correlated with susceptibility to invasion across all four island groups. When islands share similar climates and habitat diversity, the number of indigenous species may be a better predictor of invasibility than indices of physical isolation because it is a composite measure of biological isolation.
The citation frequency of papers on invasion ecology published between 1981 and 2003 and that had accumulated at least 30 citations on the Web of Science on 9 August 2006 was analysed. The dataset comprised 329 papers and 27,240 citations. For each paper, the total number of citations was recorded and the annual citation rate (number of citations per year) was calculated. Papers were classified into broad research fields: plant invasions, animal invasions, biological control, and general papers (reviews and syntheses). Eight papers were cited more than 300 times, five of them dealt with general topics, and the mean value of the total number of citations across the whole data set is 82.8±73.1. The mean annual citation rate is 11.5±11.3 citations per year; six studies received on average at least 50 citations each year. About a half (50.8%) of papers in the data set deal with plant invasions. General papers are significantly more cited than papers from the other categories. The annual citation rate increased with time over the analysed period (1981-2003), by 1.0 citations per year. To compare the trends in invasion ecology with those in other fields of ecology, comparable data were compiled for population ecology and dynamics, and global change. The annual citation rate for invasion ecology as a whole increased faster than that for population ecology and dynamics, but not exponentially as is the case with studies on global change. The best-cited papers on invasion ecology were distributed among most of the top ecology journals. Those published in Oikos, Journal of Ecology, Ecological Applications and BioScience are cited 3.8-5.8 times more than the average for these journals (based on the impact factor). Papers on biodiversity, community ecology, impact, invasibility, dispersal, population ecology, competition, resources, genetical issues, biological control and species invasiveness received the highest total number of citations. However, measured by the annual citation rate, the hottest current topics in invasion ecology are the effect of global change on invasions, the role of natural enemies, character of the invasion process, evolutionary aspects, invasibility of communities and ecosystem processes. Some topics are disproportionally more cited than studied and vice versa. Studies on plant and animal invasions differ in focus: the topics of invasibility, biodiversity, resources, species invasiveness and population genetics are more emphasized in botanical studies, dispersal, competition, impact and pathways in papers dealing with animal invasions. Studies of grasslands and marine environment are most frequently cited in botanical and zoological studies, respectively. Most of the highly cited papers deal with multiple species; only 14 plant species and four animal species are the primary focus of one or more of the highly-cited papers. Twenty-two authors (4.5% of the total involved in the papers analysed), each with seven or more contributions cited at least 30 times, together contributed 49.4% of the most-cited paper, and attracted 55.6% of the total number of citations.
Attempts to predict which species will become invaders and those which will not, represent one of the main areas of interest in the study of biological invasions. At present, however, only very limited generalizations are available, based on plant physiology, genetics, demography, species behaviour in other countries, or behaviour of congeneric species. Here I report that invasiveness of pines (genus Pinus) and, very likely, other woody species of seed plants in disturbed landscapes, is predictable on the basis of a small number of attributes: small mean seed mass, short juvenile period, and short mean interval between large seed crops. Moreover, vertebrate dispersal is responsible for success of many woody invaders in disturbed as well as 'undisturbed' habitats. As for herbaceous species, their primary (native) latitudinal range seems to be the best predictor of invasiveness, at least for species introduced from Eurasia to North America.
This paper considers key issues in plant invasion ecology, where findings published since 1990 have significantly improved our understanding of many aspects of invasions. The review focuses on vascular plants invading natural and semi-natural ecosystems, and on fundamental ecological issues relating to species invasiveness and community invasibility. Three big questions addressed by the SCOPE programme in the 1980s (which species invade; which habitats are invaded; and how can we manage invasions?) still underpin most work in invasion ecology. Some organizing and unifying themes in the field are organism-focused and relate to species invasiveness (the tens rule; the concept of residence time; taxonomic patterns and Darwin's naturalization hypothesis; issues of phenotypic plasticity and rapid evolutionary change, including evolution of increased competitive ability hypothesis; the role of long-distance dispersal). Others are ecosystem-centred and deal with determinants of the invasibility of communities, habitats and regions (levels of invasion, invasibility and propagule pressure; the biotic resistance hypothesis and the links between diversity and invasibility; synergisms, mutualisms, and invasional meltdown). Some theories have taken an overarching approach to plant invasions by integrating the concepts of species invasiveness and community invasibility (a theory of seed plant invasiveness; fluctuating resources theory of invasibility). Concepts, hypotheses and theories reviewed here can be linked to the naturalization-invasion continuum concept, which relates invasion processes with a sequence of environmental and biotic barriers that an introduced species must negotiate to become casual, naturalized and invasive. New research tools and improved research links between invasion ecology and succession ecology, community ecology, conservation biology and weed science, respectively, have strengthened the conceptual pillars of invasion ecology.
Builds on material presented at the Sardinian EMAPi (Ecology and Managment of Alien Plant invasions) conference where more than 100 contributions (papers and posters) were received from 20 countries across 5 continents. In an attempt to quantify and further the understanding of ecological issues relating to plant invasions, this work contains case study papers on the ecology of single invasive plant species. It also addresses general questions on invasion biology and explores the control and management of invasive species in a wide range of ecosystems. Reviewed at:
How Important are Rivers for Supporting Plant Invasions? The Giant Hogweed Problem in Sweden: Suggestions for its Management and Control Giant Hogweed and its Control in Scotland Controlling Invasive Weeds using Glyphosate Alien Weeds - A National Rivers Authority Perspective.
The number of studies dealing with plant invasions is increasing rapidly, but the accumulating body of knowledge has unfortunately also spawned increasing confusion about terminology. Invasions are a global phenomenon and comparison of geographically distant regions and their introduced biota is a crucially important methodological approach for elucidation of the determinants of invasiveness and invasibility. Comparative studies of alien floras provide substantial new insights to our understanding of general patterns of plant invasions. Such studies, using information in previously published floras and checklists, are fundamentally dependent on the quality of the assessment of particular species with respect to their taxonomic identity, time of immigration and invasion status. Three crucial decisions should be made when defining the status of a plant species in a given region: (1) whether the taxon is native or alien to that region (origin status); (2) what is its position in the invasion process, i.e., when was it introduced (residence status); and (3) what is the degree of its naturalization and possible invasion (invasion status). Standard floras differ hugely in their treatment of non-native species and those with appropriate categorization of alien species according to their status are rather rare. The present paper suggests definitions of terms associated with plant invasions and places these into the context of floras. Recommendations are outlined on how to deal with the issue of plant invasions in standard floras with the aim of contributing to a better understanding between taxonomists and ecologists and allowing more detailed comparative analyses of alien floras of various regions of the world.