
Exotic invasive species in urban wetlands: environmental correlates and implications for
wetland management.Preview By: Ehrenfeld, Joan G.. Journal of Applied Ecology, Aug2008, Vol. 45 Issue
4, p1160-1169, 10p, 2 graphs; DOI: 10.1111/j.1365-2664.2008.01476.x; (AN 33017702)
Abstract Only
1. Wetlands in urban regions are subjected to a wide variety of anthropogenic disturbances, many of
which may promote invasions of exotic plant species. In order to devise management strategies, the
influence of different aspects of the urban and natural environments on invasion and community
structure must be understood. 2. The roles of soil variables, anthropogenic effects adjacent to and
within the wetlands, and vegetation structure on exotic species occurrence within 21 forested wetlands
in north-eastern New Jersey, USA, were compared. The hypotheses were tested that different
vegetation strata and different invasive species respond similarly to environmental factors, and that
invasion increases with increasing direct human impact, hydrologic disturbance, adjacent residential
land use and decreasing wetland area. Canonical correspondence analyses, correlation and logistic
regression analyses were used to examine invasion by individual species and overall site invasion, as
measured by the absolute and relative number of exotic species in the site flora. 3. Within each stratum,
different sets of environmental factors separated exotic and native species. Nutrients, soil clay content
and pH, adjacent land use and canopy composition were the most frequently identified factors affecting
species, but individual species showed highly individualistic responses to the sets of environmental
variables, often responding in opposite ways to the same factor. 4. Overall invasion increased with
decreasing area but only when sites > 100 ha were included. Unexpectedly, invasion decreased with
increasing proportions of industrial/commercial adjacent land use. 5. The hypotheses were only
partially supported; invasion does not increase in a simple way with increasing human presence and
disturbance. 6. Synthesis and applications. The results suggest that a suite of environmental conditions
can be identified that are associated with invasion into urban wetlands, which... [ABSTRACT FROM
AUTHOR]
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
Diversity, invasive species and extinctions in insular ecosystems.Preview By: Donlan, C.
Josh; Wilcox, Chris. Journal of Applied Ecology, Aug2008, Vol. 45 Issue 4, p1114-1123, 10p, 2 charts; DOI:
10.1111/j.1365-2664.2008.01482.x; (AN 33017699)
Abstract Only
1. Species invasions are a primary driver of species additions and deletions in ecosystems.
Understanding the intricacies of invasions and their consequences is central to ecology and biodiversity
conservation. Extinctions are rarely random and often are influenced by a suite of factors. 2. We
explored abiotic and biotic factors that correlate with and help to provide proximate explanations for
insular extinctions driven by invasive predators on islands off western Mexico. 3. A number of factors
that were hypothesized a priori to explain the observed extinction patterns performed better than island
size alone. Alternative prey available to invasive predators was negatively correlated with extinction,
with twice the number of alternative prey species present on extinction-free islands compared to islands
with extinctions. Carrying capacity estimates of extant populations were 27 times that of extinct
populations. 4. An aggregate model that included alternative prey, carrying capacity, and seasonal
precipitation was the best performing model. Those factors, which are supported by theory and
empirical evidence, are informative to conservation decision-makers. 5. Synthesis and applications.
Islands with small native mammals and no, or few, alternative prey species available to invasive
predators should be prioritized for eradication. By focusing regionally on a specific threat, we provide a
framework to practitioners that aids in prioritizing invasive predator eradications to halt insular
extinctions. [ABSTRACT FROM AUTHOR]
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
The presence of a showy invasive plant disrupts pollinator service and reproductive
output in native alpine species only at high densities.Preview By: Muñoz, Alejandro A.; Cavieres,
Lohengrin A.. Journal of Ecology, May2008, Vol. 96 Issue 3, p459-467, 9p, 1 chart, 3 graphs; DOI:
10.1111/j.1365-2745.2008.01361.x; (AN 31601048)
Abstract Only
1. Alien invasive plants possessing attractive flowers can affect the interactions between native plants
and their pollinators. The few studies conducted so far have reported positive, negative and neutral
effects of the presence of an invasive species on the pollinator visitation rates and seed output of native
species. However, the role played by the density of the alien species has been seldom explored. 2.
While high densities of the invasive species can negatively effect the pollinator visitation rates and seed
output of the native species, due to sequestration of pollinators by the invasive species, at lower
densities the invasive can attract pollinators that otherwise would not visit patches of native species,
positively affecting their reproduction. 3. Using observations and pollinator exclusions at a site at
2800 m altitude in the central Chilean Andes, we show that the alien herb Taraxacum officinale
(Asteraceae), possessing showy floral capitula, shares pollinators to a high degree (> 90%) with two cooccurring native Asteraceae: Hypochaeris thrincioides and Perezia carthamoides. Pollinator exclusion
indicated that both natives are highly dependent on insect visitation to produce seeds. 4. Using
manipulative supplemental hand-pollination and experiments, where we varied the density of T.
officinale, we determined that seed output in H. thrincioides and P. carthamoides is pollen-limited and
that its magnitude is not affected by the presence of the exotic. Further, while the presence of one
individual of T. officinale around focal native individuals showed neutral or facilitative effects on
pollinator service or seed output in the two native species, the presence of five individuals of T.
officinale negatively affected these reproductive variables. 5. Synthesis. Our results suggest that the
effects of the presence of alien invasive plant species with attractive flowers vary with their density.
This demonstrates the need to... [ABSTRACT FROM AUTHOR]
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
Modelling invasion for a habitat generalist and a specialist plant species.Preview By:
Evangelista, Paul H.; Kumar, Sunil; Stohlgren, THomas J.; Jarnevich, Catherine S.; Crall, Alycia W.; Norman
III, John B.; Barnett, David T.. Diversity & Distributions, Sep2008, Vol. 14 Issue 5, p808-817, 10p, 2 charts, 2
color; DOI: 10.1111/j.1472-4642.2008.00486.x; (AN 33654377)
Abstract Only
Predicting suitable habitat and the potential distribution of invasive species is a high priority for
resource managers and systems ecologists. Most models are designed to identify habitat characteristics
that define the ecological niche of a species with little consideration to individual species’ traits. We
tested five commonly used modelling methods on two invasive plant species, the habitat generalist
Bromus tectorum and habitat specialist Tamarix chinensis, to compare model performances, evaluate
predictability, and relate results to distribution traits associated with each species. Most of the tested
models performed similarly for each species; however, the generalist species proved to be more
difficult to predict than the specialist species. The highest area under the receiver-operating
characteristic curve values with independent validation data sets of B. tectorum and T. chinensis was
0.503 and 0.885, respectively. Similarly, a confusion matrix for B. tectorum had the highest overall
accuracy of 55%, while the overall accuracy for T. chinensis was 85%. Models for the generalist
species had varying performances, poor evaluations, and inconsistent results. This may be a result of a
generalist's capability to persist in a wide range of environmental conditions that are not easily defined
by the data, independent variables or model design. Models for the specialist species had consistently
strong performances, high evaluations, and similar results among different model applications. This is
likely a consequence of the specialist's requirement for explicit environmental resources and ecological
barriers that are easily defined by predictive models. Although defining new invaders as generalist or
specialist species can be challenging, model performances and evaluations may provide valuable
information on a species’ potential invasiveness. [ABSTRACT FROM AUTHOR]
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Abstracts)

PLASTICITY IN SALT TOLERANCE TRAITS ALLOWS FOR INVASION OF
NOVEL HABITAT BY JAPANESE KNOTWEED S. L. (FALLOPIA JAPONICA AND F.
XBOHEMICA, POLYGONACEAE).Preview By: Richards, Christina L.; Walls, Ramona L.; Bailey,
John P.; Parameswaran, Radha; George, Tara; Piguucci, Massimo. American Journal of Botany, Aug2008, Vol.
95 Issue 8, p931-942, 12p, 3 charts, 3 graphs; DOI: 10.3732/ajb.2007364; (AN 34123854)
Abstract Only
Japanese knotweeds are among the most invasive organisms in the world. Their recent expansion into
salt marsh habitat provides a unique opportunity to investigate how invasives establish in new
environments. We used morphology, cytology, and AFLP genotyping to identify taxa and clonal
diversity in roadside and salt marsh populations. We conducted a greenhouse study to determine the
ability to tolerate salt and whether salt marsh populations are more salt tolerant than roadside
populations as measured by the efficiency of PSII, leaf area, succulence, height, root-to-shoot ratio, and
total biomass. Clonal diversity was extremely low with one F. japonica clone and five F. ×bohemica
genotypes. The two taxa were significantly different in several traits, but did not vary in biomass or
plasticity of any trait. All traits were highly plastic in response to salinity, but differed significantly
among genets. Despite this variation, plants from the salt marsh habitats did not perform better in the
salt treatment, suggesting that they are not better adapted to tolerate salt. Instead, our data support the
hypothesis that plasticity in salt tolerance traits may allow these taxa to live in saline habitats without
specific adaptation to tolerate salt. [ABSTRACT FROM AUTHOR]
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
The Relation of Density Regulation to Habitat Specialization, Evolution of a Species'
Range, and the Dynamics of Biological Invasions.Preview By: Filin, Ido; Holt, Robert D.; Barfield,
Michael. American Naturalist, Aug2008, Vol. 172 Issue 2, p233-247, 15p; DOI: 10.1086/589459; (AN
33960043)
Abstract Only
Prior studies of the evolution of species' niches and ranges have identified the importance of withinpopulation genetic variance, migration rate, and environmental heterogeneity in determining
evolutionarily stable patterns of species' range and habitat use. Different combinations of these
variables can produce either habitat specialists or generalists and cause either stable range limits or
unbounded expansion. We examine the effect of density regulation on a species' range and habitat use
within a landscape comprised of two discrete habitats and along continuous environmental gradients.
Using the theta-logistic formulation, we demonstrate the following. (1) Spatially uniform density
regulation generally weakens gene swamping and opposes habitat specialization and range limitation.
(2) The form of density regulation should play an important role in determining whether the
equilibrium species' range is limited by gene flow. (3) Even when no long-term limited-range
equilibrium occurs, quasi-stable (or even contracting) range limits may be maintained for a long
period during the initial phases of an invasion; the length of this period depends on the form of density
regulation. (4) The steady state invasion speed in heterogeneous environments depends on the form of
density regulation. Implications for the study of biological invasions are discussed, and directions for
further exploration are sketched.

Increased abundance of native and non-native spiders with habitat
fragmentation.Preview By: Bolger, Douglas T.; Beard, Karen H.; Suarez, Andrew V.; Case, Ted J..
Diversity & Distributions, Jul2008, Vol. 14 Issue 4, p655-665, 11p, 3 charts, 2 graphs, 1 map; DOI:
10.1111/j.1472-4642.2008.00470.x; (AN 32549390)
Abstract Only
Habitat fragmentation and invasive species often contribute to the decline of native taxa. Since the
penetration of non-native species into natural habitat may be facilitated by habitat fragmentation, it is
important to examine how these two factors interact. Previous research documented that, in contrast to
most other arthropod taxa, spiders increased in density and morphospecies richness with decreasing
fragment area and increasing fragment age (time since insularization) in urban habitat fragments in San
Diego County, California, USA. We tested whether a specific mechanism, an increase in non-native
species with fragmentation, is responsible for this pattern. We found that both native and non-native
taxa contributed to the pattern. Abundance of native spiders per pitfall trap sample increased
significantly with decreasing fragment size (i.e. a negative density–area relationship) and abundance of
non-natives increased significantly with increasing fragment age. The proportion of non-native
individuals also increased significantly with age. One non-native species, Oecobius navus, comprised
the majority of non-native individuals (82.2%) and a significant proportion of total individuals (25.1%).
Richness of spider families per sample (family density) increased with fragment age due to an increase
in the occurrence of non-natives in older fragments, however, native family richness did not vary with
age or area. Due to increasing dominance by non-native and some native families, family evenness
declined with decreasing fragment size and increasing fragment age. Native and non-native abundance
covaried positively arguing against strong negative interactions between the two groups. O. navus had a
strong positive association with another common non-native arthropod, the Argentine ant ( Linepitheme
humile), suggesting a possible direct interaction. In contrast, abundance of native spiders was
negatively correlated with Argentine ant abundance. We... [ABSTRACT FROM AUTHOR]
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Abstracts)

Impacts of alien invasive plants on soil nutrients are correlated with initial site conditions
in NW Europe.Preview By: Dassonville, Nicolas; Vanderhoeven, Sonia; Vanparys, Valérie; Hayez,
Mathieu; Gruber, Wolf; Meerts, Pierre. Oecologia, Jul2008, Vol. 157 Issue 1, p131-140, 10p, 3 charts, 2 graphs;
DOI: 10.1007/s00442-008-1054-6; (AN 33005519)
Abstract Only
Alien invasive plants are capable of modifying ecosystem function. However, it is difficult to make
generalisations because impacts often appear to be species- and site-specific. In this study, we
examined the impacts of seven highly invasive plant species in NW Europe ( Fallopia japonica,
Heracleum mantegazzianum, Impatiens glandulifera, Prunus serotina, Rosa rugosa, Senecio
inaequidens, Solidago gigantea) on nutrient pools in the topsoil and the standing biomass. We tested if
the impacts follow predictable patterns, across species and sites or, alternatively, if they are entirely
idiosyncratic. To that end, we compared invaded and adjacent uninvaded plots in a total of 36 sites with
widely divergent soil chemistry and vegetation composition. For all species, invaded plots had
increased aboveground biomass and nutrient stocks in standing biomass compared to uninvaded
vegetation. This suggests that enhanced nutrient uptake may be a key trait of highly invasive plant
species. The magnitude and direction of the impact on topsoil chemical properties were strongly sitespecific. A striking finding is that the direction of change in soil properties followed a predictable
pattern. Thus, strong positive impacts (higher topsoil nutrient concentrations in invaded plots compared
to uninvaded ones) were most often found in sites with initially low nutrient concentrations in the
topsoil, while negative impacts were generally found under the opposite conditions. This pattern was
significant for potassium, magnesium, phosphorus, manganese and nitrogen. The particular site-specific
pattern in the impacts that we observed provides the first evidence that alien invasive species may
contribute to a homogenisation of soil conditions in invaded landscapes. [ABSTRACT FROM
AUTHOR]
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
Is exotic plant invasion enhanced by a traditional wildlife habitat management
technique?Preview By: Johnson, M.V.V.; Fulbright, T.E.. Journal of Arid Environments, Oct2008,
Vol. 72 Issue 10, p1911-1917, 7p; DOI: 10.1016/j.jaridenv.2008.04.006; (AN 33640890)
Abstract Only
Abstract: Soil disturbance is a wildlife habitat management tool that retards succession and
promotes early seral vegetation. Our objective was to determine responses of two invasive
herbaceous species (Pennisetum ciliare and Salsola iberica) and native perennial grasses to
disking on different soils. Two 10×40m plots were delineated within each of 4 blocks on
Ramadero loams and 4 blocks on Delmita fine sandy loams. On Delmita soils, canopy cover of
P. ciliare, S. iberica, and native perennial grasses averaged across all years was not affected
by disking (ANOVA, P>0.05). On Ramadero soils, P. ciliare canopy cover was similar (Tukey's,
P>0.05) on control and disked plots for the first 4 years post-disturbance, but P. ciliare cover
was 10-fold greater (Tukey's, P=0.02) the 5th year after disking on disked versus control
plots. On Ramadero soils, S. iberica canopy cover averaged across all years was 221 times
greater (ANOVA, P=0.05) on disked plots than on control plots. Disking did not affect native
perennial grass canopy cover. Land managers should consider soil series when disking for
wildlife management, as disking disturbance may exacerbate exotic plant ingress and
establishment on certain soils. [Copyright 2008 Elsevier]
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
Impacts of a woody invader vary in different vegetation communities.Preview
By: Mason, T. J.; French, K.. Diversity & Distributions, Sep2008, Vol. 14 Issue 5, p829-838, 10p, 5
charts, 1 graph; DOI: 10.1111/j.1472-4642.2008.00493.x; (AN 33654374)
Abstract Only
The impact of an exotic species in natural systems may be dependent not only on invader
attributes but also on characteristics of the invaded community. We examined impacts of the
invader bitou bush, Chrysanthemoides monilifera ssp. rotundata, in fore and hind dune
communities of coastal New South Wales, Australia. We compared invader impacts on
vegetation structure, richness of both native and exotic growth forms and community
variability in fore and hind dunes. We found that impacts of bitou invasion were context
specific: in fore dune shrublands, functionally distinct graminoid, herb and climber rather than
shrub growth forms had significantly reduced species richness following bitou invasion.
However, in forested hind dunes, the functionally similar native shrub growth form had
significantly reduced species richness following bitou invasion. Density of vegetation
structure increased at the shrub level in both fore and hind dune invaded communities
compared with non-invaded communities. Fore dune ground-level vegetation density declined
at invaded sites compared with non-invaded sites, reflecting significant reductions in herb and
graminoid species richness. Hind dune canopy-level vegetation density was reduced at
invaded compared with non-invaded sites. Bitou bush invasion also affected fore dune
community variability with significant increases in variability of species abundances observed
in invaded compared with non-invaded sites. In contrast, variability among all hind dune sites
was similar. The results suggest that effects of bitou bush invasion are mediated by the
vegetation community. When bitou bush becomes abundant, community structure and
functioning may be compromised. [ABSTRACT FROM AUTHOR]
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
POPULATION FEEDBACK AFTER SUCCESSFUL INVASION LEADS TO
ECOLOGICAL SUICIDE IN SEASONAL ENVIRONMENTS.Preview By: van de Wolfshaar, K. E.;
de Roos, A. M.; Persson, L.. Ecology, Jan2008, Vol. 89 Issue 1, p259-268, 10p, 4 graphs; (AN
31275232)
Abstract Only
For most consumer species, winter represents a period of harsh food conditions in addition to
the physiological strain that results from the low ambient temperatures. In size- structured
populations, larger-bodied individuals do better during winter as they have larger energy
reserves to buffer starvation periods. In contrast, smaller-bodied individuals do better under
growing conditions, as they have lower maintenance costs. We study how the interplay
between size-dependent life-history processes and seasonal changes in temperature and food
availability shape the long-term dynamics of a size-structured consumer population and its
unstructured resource. We show that the size dependence of maintenance requirements
translates into a minimum body size that is needed for surviving starvation when consumers
can adapt only to a limited extent to the low food densities in winter. This size threshold can
lead to population extinction because adult individuals suffer only a little during winter and
hence produce large numbers of offspring. Due to population feedback on the resource and
intense intra-cohort competition, newborn consumers then fail to reach the size threshold for
survival. Under these conditions, small numbers of individuals can survive, increase in density,
and build up a population, which will subsequently go extinct due to its feedback on the
resource. High juvenile mortality may prevent this ecological suicide from occurring, as it
releases resource competition among newborns and speeds up their growth. In sizestructured populations, annual fluctuations in temperature and food availability may thus lead
to a conflict between individual fitness and population persistence. [ABSTRACT FROM
AUTHOR]
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
Intraspecific diversity and dominant genotypes resist plant invasions.Preview
By: Crutsinger, Gregory M.; Souza, Lara; Sanders, Nathan J.. Ecology Letters, Jan2008, Vol. 11 Issue
1, p16-23, 8p, 2 charts, 3 graphs; DOI: 10.1111/j.1461-0248.2007.01118.x; (AN 27824900)
Abstract Only
Numerous studies have asked whether communities with many species deter invasions more
so than do species-poor communities or whether dominant species deter invasion by
colonizing species. However, little is known about whether high intraspecific diversity can
deter biological invasions or whether particular genotypes might deter invasions. In this
study, we present experimental evidence that intraspecific diversity and particular genotypes
of tall goldenrod, Solidago altissima, can act as a barrier to colonization by new species. We
found that biomass of colonizing species was negatively correlated with genotypic diversity,
and particular genotypes affected the richness, cover, and biomass of colonizing species.
Stem density of S. altissima increased with genotypic diversity and varied among genotypes,
suggesting that stem density is a key mechanism in limiting colonization dynamics in this
system. Our results indicate that the loss of intraspecific diversity within a dominant plant
species can increase susceptibility to plant invasions. [ABSTRACT FROM AUTHOR]
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
Exotic invasive plant accumulates native soil pathogens which inhibit native
plants.Preview By: Mangla, Seema; Callaway, Ragan M.. Journal of Ecology, Jan2008, Vol. 96
Issue 1, p58-67, 10p, 6 graphs; DOI: 10.1111/j.1365-2745.2007.01312.x; (AN 27825015)
Abstract Only
1. We investigated the role of a native generalist soil pathogen through which a non-native
invasive plant species may suppress naturalized/native plant species. 2. We found that
rhizosphere soils of Chromolaena odorata, one of the world's most destructive tropical
invasive weeds, accumulate high concentrations of the generalist soil borne fungi, Fusarium
(tentatively identified as F. semitectum), thus creating a negative feedback for native plant
species. 3. Soils collected beneath Chromolaena in the Western Ghats of India inhibited
naturalized/native species and contained over 25 times more spores of the pathogenic fungi
Fusarium semitectum than soils collected at the same locations beneath neighbouring native
species that were at least 20 m from any Chromolaena plant. Sterilization of these soils
eliminated their inhibitory effect. Chromolaena root leachate experimentally added to
uninvaded soils increased Fusarium spore density by over an order of magnitude, and
increased the inhibitory effect of the soils. 4. The positive effect of Chromolaena root
leachates on Fusarium spores was attenuated by activated carbon, suggesting a biochemical
basis for how the invader stimulated the pathogen. 5. Synthesis. Invasive plants have been
shown to escape inhibitory soil biota in their native range and to inhibit soil biota in their
invaded range, but our results indicate that the impacts of Chromolaena are due to the
exacerbation of biotic interactions among native plants and native soil biota, which is to our
knowledge a new invasive pathway. [ABSTRACT FROM AUTHOR]
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may not be copied or emailed to multiple sites or posted to a listserv without the copyright
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
Are Invaders Moving Targets? The Generality and Persistence of Advantages in
Size, Reproduction, and Enemy Release in Invasive Plant Species with Time since
Introduction.Preview By: Hawkes, Christine V.. American Naturalist, Dec2007, Vol. 170 Issue 6,
p832-843, 12p, 1 chart, 1 diagram, 4 graphs; DOI: 10.1086/522842; ( AN 28038887)
Abstract Only
Successful plant invasions are often attributed to increased plant size, reproduction, or
release from natural enemies, but the generality and persistence of these patterns remains
widely debated, Meta-analysis was used to quantitatively assess invasive plant performance
and release from enemy damage and how these change with residence time and geographic
distribution. Invasive plants were compared either in their introduced and home ranges or
with native congeners in the introduced range. Invasive plants in the introduced range were
generally larger, allocated more to reproduction, and had lower levels of herbivore damage
compared with conspecifics in the home range; pathogen attack, however, varied widely. In
congener comparisons, invasive and native plants did not differ in size or herbivory, but
invaders did allocate less to reproduction and had lower levels of pathogen damage. Time
since introduction was a significant nonlinear predictor of enemy release for both herbivores
and pathogens, with initial release in recently arrived species and little to no release after 50
to 200 years. Geographic distribution was also a significant nonlinear predictor of enemy
release. The observed nonlinear relationships are consistent with dynamic invasions and
may define targets for eradication efforts if these patterns hold up for individual species.
[ABSTRACT FROM AUTHOR]
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
Phylogenetically Independent Associations between Autonomous Self-Fertilization
and Plant Invasiveness.Preview By: van Kleunen, Mark; Manning, John C.; Pasqualetto,
Vanessa; Johnson, Steven D.. American Naturalist, Feb2008, Vol. 171 Issue 2, p195-201, 7p; DOI:
10.1086/525057; (AN 28626561)
Abstract Only
Many plant species have been introduced from their native ranges to new continents, but
few have become naturalized or, ultimately, invasive. It has been predicted that species that
do not require the presence of compatible mates and the services of pollinators for
reproduction will be favored in establishment after longdistance dispersal. We tested whether
this hypothesis, generally referred to as Baker's law, holds for South African species of
Iridaceae (iris family) that have been introduced in other regions for horticultural purposes.
Fruit and seed production of flowers from which pollinators had been experimentally excluded
was assessed for 10 pairs of species from nine different genera or subgenera. Each species
pair comprised one naturalized and one nonnaturalized species, all of which are used in
international horticulture. On average, species of Iridaceae that have become naturalized
outside their native ranges showed a higher capacity for autonomous fruit and seed
production than congeneric species that have not become naturalized. This was especially
true for the naturalized species that are considered to be invasive weeds. These results
provide strong evidence for the role of autonomous seed production in increasing potential
invasiveness in plants. [ABSTRACT FROM AUTHOR]
Copyright of American Naturalist is the property of University of Chicago Press and its content
may not be copied or emailed to multiple sites or posted to a listserv without the copyright
holder's express written permission. However, users may print, download, or email articles for
individual use. This abstract may be abridged. No warranty is given about the accuracy of the
copy. Users should refer to the original published version of the material for the full abstract.
(Copyright applies to all Abstracts)
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HIGH SEEDLING RELATIVE GROWTH RATE AND SPECIFIC LEAF AREA ARE
TRAITS OF INVASIVE SPECIES: PHYLOGENETICALLY INDEPENDENT CONTRASTS OF
WOODY ANGIOSPERMS.Preview By: Grotkopp, Eva; Rejmanek, Marcel. American Journal of
Botany, Apr2007, Vol. 94 Issue 4, p526-532, 7p, 3 charts; (AN 25291923)
Abstract Only
Understanding causal factors of exotic species invasions is important not only for prevention
and prioritizing control efforts, but also for providing valuable insights into the underlying
biology of contrasting life-history strategies. In seedling growth analyses, invasive woody
species were compared with less-invasive woody species commonly cultivated in California
using phylogenetically corrected procedures (12 phylogenetically independent contrasts).
Invasive species were hypothesized to have higher seedling relative growth rates (RGRs) and
specific leaf areas (SLAs) than did related less-invasive species. In phylogenetically
independent contrasts conducted among taxa within families, high seedling RGRs and SLAs
have significant positive associations with woody plant invasiveness. For contrasts
containing species invasive in mediterranean regions, invasive species had significantly larger
root biomass allocation than did less-invasive species. Optimization of fast seedling growth
(high RGR) associated with opportunistic resource acquisition (high SLA) and increased root
allocation to survive summer drought may be critical for the success of plant invaders in
regions with mediterranean climates. [ABSTRACT FROM AUTHOR]
Copyright of American Journal of Botany is the property of Botanical Society of America, Inc.
and its content may not be copied or emailed to multiple sites or posted to a listserv without
the copyright holder's express written permission. However, users may print, download, or
email articles for individual use. This abstract may be abridged. No warranty is given about
the accuracy of the copy. Users should refer to the original published version of the material
for the full abstract. (Copyright applies to all Abstracts)

Plant invasions: merging the concepts of species invasiveness and community
invasibility.Preview By: Richardson, David M.; Pyšek, Petr. Progress in Physical Geography,
Jul2006, Vol. 30 Issue 3, p409-431, 23p, 2 diagrams; DOI: 10.1191/0309133306pp490pr; (AN
21076352)
PDF Full Text
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Life-history correlates of plant invasiveness at regional and continental
scales.Preview By: Hamilton, Mark A.; Murray, Brad R.; Cadotte, Marc W.; Hose, Grant C.; Baker,
Andrew C.; Harris, Carla J.; Licari, Damian. Ecology Letters, Oct2005, Vol. 8 Issue 10, p1066-1074, 9p,
2 charts; DOI: 10.1111/j.1461-0248.2005.00809.x; (AN 18155656)
PDF Full Text
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Influence of woody invader control methods and seed availability on native and
invasive species establishment in a Hawaiian forest [electronic resource].Preview , Loh,
Rhonda K. , Biological invasions, 2008 Aug., v. 10, no. 6, p. 805-819., Dordrecht : Springer
Netherlands
Abstract Only
Linked Full Text
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Variable effects of large mammal herbivory on three non-native versus three
native woody plants [electronic resource].Preview , Knapp, Liza B., Forest ecology and
management, 2008 Feb. 20, v. 255, no. 1, p. 92-98., [Amsterdam]: Elsevier Science
Abstract Only
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Plant invasions: habitat invasibility and dominance of invasive plant
species.Preview , Inderjit, Plant and soil, 2005 Dec., v. 277, no. 1-2, p. 1-5.
Invasive plant species of the world : a reference guide to environmental weeds /
Ewald Weber.Preview , Weber, Ewald, vii, 548 p. ; 25 cm., Wallingford, Oxon, UK ; Cambridge,
MA, USA : CABI Pub., c2003.
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Classical biological control: exploiting enemy escape to manage plant invasions
[electronic resource].Preview , M©ơller-Sch©Þrer, Heinz , Biological invasions, 2008
Aug., v. 10, no. 6, p. 859-874., Dordrecht : Springer Netherlands
Abstract Only
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Plant reproductive systems and evolution during biological invasion [electronic
resource].Preview , BARRETT, SPENCER C.H., Molecular ecology, 2008 Jan., v. 17, no. 1, p. 373383., Oxford, UK : Blackwell Publishing Ltd
Abstract Only
Recent biological invasions provide opportunities to investigate microevolution during
contemporary timescales. The tempo and scope of local adaptation will be determined by the
intensity of natural selection and the amounts and kinds of genetic variation within
populations. In flowering plants, genetic diversity is strongly affected by interactions
between reproductive systems and stochastic forces associated with immigration history and
range expansion. Here, we explore the significance of reproductive system diversity for
contemporary evolution during plant invasion. We focus in particular on how reproductive
modes influence the genetic consequences of long-distance colonization and determine the
likelihood of adaptive responses during invasion. In many clonal invaders, strong founder
effects and restrictions on sexual reproduction limit opportunities for local adaptation. In
contrast, adaptive changes to life-history traits should be a general expectation in both
outbreeding and inbreeding species. We provide evidence that evolutionary modifications to
reproductive systems promote the colonizing ability of invading populations and that
reproductive timing is an important target of selection during range expansion. Knowledge of
the likelihood and speed at which local adaptation evolves in invasive plants will be
particularly important for management practices when evolutionary changes enhance
ecological opportunities and invasive spread.
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Plant invasion across space and time: factors affecting nonindigenous species
success during four stages of invasion [electronic resource].Preview , Theoharides,
Kathleen A., New phytologist, 2007 Oct., v. 176, no. 2, p. 256-273., Oxford, UK : Blackwell Publishing
Ltd
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Plant invasions in undisturbed ecosystems: The triggering attribute
approach.Preview , Gurvich, D.E., Journal of vegetation science : official organ of the International
Association for Vegetation Science, 2005 Dec., v. 16, issue 6, p. 723-728.
PDF Full Text
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Plant invasions: habitat invasibility and dominance of invasive plant
species.Preview , Inderjit, Plant and soil, 2005 Dec., v. 277, no. 1-2, p. 1-5.
PDF Full Text
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Plant invasion of native grassland on serpentine soils has no major effects upon
selected physical and biological properties.Preview , Batten, K.M., Soil biology & biochemistry,
2005 Dec., v. 37, no. 12, p. 2277-2282.
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