WorldWideScience

Sample records for invasive crayfish species

  1. SHELTER COMPETITION BETWEEN TWO INVASIVE CRAYFISH SPECIES: A LABORATORY STUDY

    Directory of Open Access Journals (Sweden)

    ALONSO F.

    2006-01-01

    Full Text Available Alien crayfishes represent a common threat to aquatic ecosystems. Their spread in Europe is leading to more frequent contacts between different invasive species populations. Shelter can be an important factor in the resulting interactions. A laboratory experiment was designed to analyse the competition for shelter in similarly sized males of two species that show an invasive behaviour in Spain, Pacifastacus leniusculus and Procambarus clarkii. We carried out 24 heterospecific, six-hour trials, with 30 min behavioural observations per hour. Most often, red swamp crayfish were both the first (70.8% and the long-term winner (62.5%. Usually, the long-term winner was the first winner. Whenever shelter was occupied, a passive behaviour by unsheltered individuals was more frequent in signal crayfish than in red swamp crayfish. When both were unsheltered, signal crayfish displayed more often a passive behaviour. Although the observed behaviour might be explained as the result of dominance by the red swamp crayfish over the signal crayfish, shelter availability and class, as well as different growth patterns and population size structures, could change the intensity and the outcome of the encounters in the wild, where signal crayfish usually reach larger sizes than red swamp crayfish.

  2. Invasive crayfish in the Pacific Northwest

    Science.gov (United States)

    Pearl, Christopher A.; McCreary, Brome; Adams, Michael

    2011-01-01

    Invasive species directly threaten freshwater biodiversity, particularly in regions of high aquatic richness like the Pacific Northwest (PNW). Crayfish are among the most impactful of aquatic invasive species. Invasive crayfish are considered ecosystem engineers due to their ability to alter basic wetland properties, such as reducing vegetation and bank integrity and increasing turbidity. In areas where invasion is advanced, crayfish pose major economic and ecological problems. Crayfish have been widely introduced for aquaculture and can become established in a wide range of habitat conditions. They also may be spread by anglers who use them as bait. Several non-native crayfish are established in the PNW, but the extent of their invasion is not well known. At least two groups are known from scattered sites in the PNW, and both have proven problematic for native species in other parts of the world: Red swamp crayfish (Procambarus clarkii) and several members of the genus Orconectes. Both groups are native to areas of the eastern United States. Both are identified globally as invasives of high concern and appear on the Oregon Department of Fish and Wildlife's "10 Most Unwanted" and the U.S. Forest Service's "Primary Species of Concern" lists for stream systems in the PNW. Despite the presence of introduced crayfish in the PNW and their high potential for negative effects, the scope of their invasion and effects on aquatic systems are not well known. The U.S. Geological Survey (USGS), along with local groups and state agencies, is working to clarify crayfish distribution and to outline which basins may not yet be invaded. Other goals are to improve understanding of habitat associations of invasive crayfish and their potential effects on native crayfish.

  3. Freshwater crayfish invasions in South Africa: past, present and ...

    African Journals Online (AJOL)

    Freshwater crayfish invasions have been studied around the world, but less so in Africa, a continent devoid of native freshwater crayfish. The present study reviews historical and current information on alien freshwater crayfish species introduced into South Africa and aims to indicate which areas are at risk from invasion.

  4. Incomes, Attitudes, and Occurrences of Invasive Species: An Application to Signal Crayfish in Sweden

    Science.gov (United States)

    Gren, Ing-Marie; Campos, Monica; Edsman, Lennart; Bohman, Patrik

    2009-02-01

    This article analyzes and carries out an econometric test of the explanatory power of economic and attitude variables for occurrences of the nonnative signal crayfish in Swedish waters. Signal crayfish are a carrier of plague which threatens the native noble crayfish with extinction. Crayfish are associated with recreational and cultural traditions in Sweden, which may run against environmental preferences for preserving native species. Econometric analysis is carried out using panel data at the municipality level with economic factors and attitudes as explanatory variables, which are derived from a simple dynamic harvesting model. A log-normal model is used for the regression analysis, and the results indicate significant impacts on occurrences of waters with signal crayfish of changes in both economic and attitude variables. Variables reflecting environmental and recreational preferences have unexpected signs, where the former variable has a positive and the latter a negative impact on occurrences of waters with signal crayfish. These effects are, however, counteracted by their respective interaction effect with income.

  5. Competitive interactions between co-occurring invaders: identifying asymmetries between two invasive crayfish species

    NARCIS (Netherlands)

    Hudina, S.; Galic, N.G.; Roessink, I.; Hock, K.

    2011-01-01

    Ecosystems today increasingly suffer invasions by multiple invasive species. Complex interactions between invasive species can have different fitness implications for each invader, which can in turn determine the future progression of their invasions and result in differential impacts on native

  6. Impacts of drought and crayfish invasion on stream ecosystem structure and function

    Science.gov (United States)

    Magoulick, Daniel D.

    2014-01-01

    Drought and seasonal drying can be important disturbance events in many small streams, leading to intermittent or isolated habitats. Many small streams contain crayfish populations that are often keystone or dominant species in these systems. I conducted an experiment in stream mesocosms to examine the effects of drought and potential ecological redundancy of a native and invasive crayfish species. I examined the effects of drought (drought or control) and crayfish presence (none, native crayfish Orconectes eupunctus or invasive crayfish Orconectes neglectus) on stream mesocosm structure and function (leaf breakdown, community metabolism, periphyton, sediment and chironomid densities) in a fully factorial design. Each mesocosm contained a deep and shallow section, and drought treatments had surface water present (5-cm depth) in deep sections where tiles and leaf packs were placed. Drought and crayfish presence did not interact for any response variable. Drought significantly reduced leaf breakdown, and crayfish presence significantly increased leaf breakdown. However, the native and invasive crayfish species did not differ significantly in their effects on leaf breakdown. Drought significantly reduced primary production and community respiration overall, whereas crayfish presence did not significantly affect primary production and community respiration. Neither drought nor crayfish presence significantly affected periphyton overall. However, drought significantly reduced autotrophic index (AI), and crayfish presence increased AI. Inorganic sediment and chironomid density were not affected by drought, but both were significantly reduced by crayfish presence. O. eupunctus reduced AI and sediment more than O. neglectus did. Neither drought nor crayfish species significantly affected crayfish growth or survival. Drought can have strong effects on ecosystem function, but weaker effects on benthic structure. Crayfish can have strong effects on ecosystem

  7. FEEDING PREFERENCES OF THE INVASIVE CRAYFISH, PROCAMBARUS CLARKII

    Directory of Open Access Journals (Sweden)

    Gherardi Francesca

    2007-10-01

    Full Text Available This laboratory study analyzes feeding preferences of a crayfish species with high invasive potentials, the red swamp crayfish Procambarus clarkii. We first conducted a series of multiple-choice tests among fresh plants (3 tests, one per each of three seasons, i.e. spring, summer, and autumn and animals (1 test in summer. In the first tests, crayfish were simultaneously offered fresh pieces of seven plants of different growth forms and taxonomic groups, selected on the basis of their availability in the habitat. In the second test, the offered animals were dead earthworms, rainbow trout fry, and toad tadpoles. Then, a binary choice test was run in autumn between the most preferred plant (Urtica sp. and earthworms. The percentages of organic C and N contents were measured for each food category using a gas-chromatography technique and the assimilation efficiency of both dry mass and organic content was assessed in a dedicated experiment. The results showed that P. clarkii is selective when offered fresh plants, consuming a relatively larger biomass of Urtica (in the three seasons examined, green algae (in spring, and Polygonum (in summer and autumn. Surprisingly, crayfish did not exhibit preference for any animal prey. Also, P. clarkii’s feeding decisions seemed not to be associated with either the availability of plants in the habitat or their occurrence in the gut contents of wild crayfish. Neither did their ingested biomass depend on the organic content or assimilation efficiency. Procambarus clarkii preferred Urtica sp. over earthworms, notwithstanding the higher nutritional value and assimilation efficiency of the latter. The above results might suggest that feeding preferences of the species often depend on factors other than nutritional value and digestibility. Future studies will analyze all the possible factors together in order to unravel the rules that govern feeding preferences in crayfish. In the case of invasive species, such

  8. Expansion of the marbled crayfish in Slovakia: beginning of an invasion in the Danube catchment?

    Directory of Open Access Journals (Sweden)

    Boris Lipták

    2016-01-01

    Full Text Available The marbled crayfish, Procambarus fallax f. virginalis, is a taxon widely available in the aquarium pet trade, which has been introduced to open waters in several European countries and in Madagascar. Recent studies confirmed this parthenogenetically reproducing crayfish as a high-risk invasive species, and vector of the crayfish plague pathogen, Aphanomyces astaci. It has been first discovered in Slovakia in 2010, but the status of the local population was not studied since then. Due to enlarged sampling area around the first report and one locality, where we presupposed the crayfish occurrence, we identified new marbled crayfish populations. Here, we report presence of three newly established marbled crayfish populations in Slovakia. Two populations are located critically close to the Váh River, a major tributary of the Danube River; one of them being directly connected to the Váh River via a side channel during occasional floods. The third established marbled crayfish population was found at the mouth of a thermal stream flowing into the Nitra River, a tributary of the Váh River. In this stream, crayfish coexist with other exotic fish and gastropod species of aquarium origin. We presume that the reported localities may serve as a source for further expansion of the marbled crayfish in the mid-part of the Danube catchment. Floods, active dispersal (including overland, passive dispersal by zoochory or anthropogenic translocations are among the major drivers facilitating the marbled crayfish colonization. We have not detected the crayfish plague pathogen in any of the studied populations. However, if spreading further, the marbled crayfish will encounter established populations of crayfish plague carriers in the Danube River, in which case they may acquire the pathogen by horizontal transmission and contribute to spread of this disease to indigenous European crayfish species.

  9. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    Science.gov (United States)

    van der Wal, Jessica E M; Dorenbosch, Martijn; Immers, Anne K; Vidal Forteza, Constanza; Geurts, Jeroen J M; Peeters, Edwin T H M; Koese, Bram; Bakker, Elisabeth S

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  10. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species.

    Science.gov (United States)

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-02-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates.

  11. Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?

    Directory of Open Access Journals (Sweden)

    Ruokonen T. J.

    2016-01-01

    Full Text Available Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recently introduced. Our results revealed that signal crayfish had temporally rather consistent negative effects on the benthic macroinvertebrate assemblages but that the effects might be limited to certain taxa, in particular Gastropoda and Coleoptera. We also observed increases in Gastropoda density and taxa richness following a decline in crayfish density, indicating that the recovery of invertebrate assemblages might be fast. Hence, negative effects on benthic macroinvertebrates can likely be minimized by effective control of the signal crayfish population.

  12. Phylogenetic species delimitation for crayfishes of the genus Pacifastacus.

    Science.gov (United States)

    Larson, Eric R; Castelin, Magalie; Williams, Bronwyn W; Olden, Julian D; Abbott, Cathryn L

    2016-01-01

    Molecular genetic approaches are playing an increasing role in conservation science by identifying biodiversity that may not be evident by morphology-based taxonomy and systematics. So-called cryptic species are particularly prevalent in freshwater environments, where isolation of dispersal-limited species, such as crayfishes, within dendritic river networks often gives rise to high intra- and inter-specific genetic divergence. We apply here a multi-gene molecular approach to investigate relationships among extant species of the crayfish genus Pacifastacus, representing the first comprehensive phylogenetic study of this taxonomic group. Importantly, Pacifastacus includes both the widely invasive signal crayfish Pacifastacus leniusculus, as well as several species of conservation concern like the Shasta crayfish Pacifastacus fortis. Our analysis used 83 individuals sampled across the four extant Pacifastacus species (omitting the extinct Pacifastacus nigrescens), representing the known taxonomic diversity and geographic distributions within this genus as comprehensively as possible. We reconstructed phylogenetic trees from mitochondrial (16S, COI) and nuclear genes (GAPDH), both separately and using a combined or concatenated dataset, and performed several species delimitation analyses (PTP, ABGD, GMYC) on the COI phylogeny to propose Primary Species Hypotheses (PSHs) within the genus. All phylogenies recovered the genus Pacifastacus as monophyletic, within which we identified a range of six to 21 PSHs; more abundant PSHs delimitations from GMYC and ABGD were always nested within PSHs delimited by the more conservative PTP method. Pacifastacus leniusculus included the majority of PSHs and was not monophyletic relative to the other Pacifastacus species considered. Several of these highly distinct P. leniusculus PSHs likely require urgent conservation attention. Our results identify research needs and conservation priorities for Pacifastacus crayfishes in western

  13. Distribution of crayfish species in Hungarian waters

    NARCIS (Netherlands)

    Mercédesz, Ludányi; Peeters, E.T.H.M.; Kiss, B.; Roessink, I.

    2016-01-01

    Three native crayfish species, i.e.~Astacus astacus, Astacus leptodactylus and Austropotamobius torrentium, occur in Hungary. Lately, however, non-indigenous crustaceans have also invaded the country Their most recent distribution and impact on the occurrences of the native species is not clear.

  14. Red swamp crayfish: biology, ecology and invasion - an overview

    Directory of Open Access Journals (Sweden)

    Tainã Gonçalves Loureiro

    Full Text Available ABSTRACTAlien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modifications in invaded environments causing irreparable ecological and economic damages. Its impressive ability to successfully colonize a wide range of environments is a consequence of its behavioural and biological characteristics that can adapt to features of the invaded location, conferring to this species a notable ecological plasticity. This review summarizes the available information regarding P. clarkii's biology and invasive dynamics around the world in order to contribute to the understanding of the threats posed by its establishment, as well as to support management and impact mitigation efforts.

  15. INTERACTION BETWEEN NATIVE AND ALIEN SPECIES OF CRAYFISH IN AUSTRIA: CASE STUDIES

    Directory of Open Access Journals (Sweden)

    PÖCKL M.

    2002-07-01

    Full Text Available In Austria, three indigenous crayfish species occur: the noble crayfish (Astacus astacus, the stone crayfish (Austropotamobius torrentium, and the white-clawed crayfish (Austropotamobius pallipes. It is not known if Astacus leptodactylus is autochthonous in the very eastern part of Austria, near the border with Hungary and Slovakia. In other parts of Austria the Turkish crayfish has been transplanted into several gravel pits and ponds. Up to now, the red swamp crayfish (Procambarus clarkii is not known to occur in the wild, but can be bought alive in fish markets, restaurants, and the aquarium trade. The Nearctic spiny-cheek crayfish (Orconectes limosus and the signal crayfish (Pacifastacus leniusculus have been introduced since the 1970s by crayfish farmers because these species are resistant to the crayfish plague fungus (Aphanomyces astaci. There are just a few populations of O. limosus, and the species is not spreading actively. However, P. leniusculus is widespread all over Austria, and was illegally introduced from one water body to another. It can be characterized as an aggressive, invasive North American species, spreading actively and acting as a vector of the crayfish plague. Unfortunately the habitat requirements of the native noble crayfish and the alien signal crayfish are nearly the same. Case studies are given in the following chapters: the first group of examples refers to water bodies where the alien signal crayfish is most probably the cause of displacement of the indigenous noble crayfish: 1 Hintersee, 2 Irrsee (« Zeller See », 3 north-western Lower Austria (« Waldviertel », 4 Merzenstein (aquacultural enterprise, 5 Neufelder See. The second group of examples refers to water bodies where alien and indigenous species are able to coexist: a the confluence of the main course of the Danube River, the Ölhafen and the Neue Donau in the southeast part of Vienna, b the Schönauer Wasser, a backwater of the Danube River downstream

  16. Continental-wide distribution of crayfish species in Europe: update and maps

    Directory of Open Access Journals (Sweden)

    Kouba A.

    2014-01-01

    Full Text Available Recently published astacological studies substantially improved available data on distribution of crayfish in various European regions. At the same time, spread of invasive species has been recorded, additional non-indigenous species became established in various countries, and losses of populations of native species due to crayfish plague and other negative factors were observed. We overview recent advances in this knowledge, and provide updated colour maps of the distribution of all crayfish species present in Europe. These maps are originally based on the data from the Atlas of Crayfish in Europe published in 2006 as a result of the CRAYNET project, and were further updated from more recently published reports, grey literature, and especially thanks to contributions and feedback of over 70 specialists from 32 countries. Separate maps are available for all indigenous crayfish species in Europe as well as for three most widespread non-indigenous crayfish species. Additionally, two maps give locations of known findings of crayfish species introduced to Europe after 1980. These newly established alien species have so far restricted distributions; however, the frequency of recent reports suggests that findings of such species resulting from releases of aquarium pets will further increase.

  17. REDUCING THE THREAT TO CONTROL INVASIVE SIGNAL CRAYFISH REDUCING: THE POTENTIAL USE OF PHEROMONES

    Directory of Open Access Journals (Sweden)

    STEBBING P. D.

    2003-04-01

    Full Text Available The need for an effective method of controlling invasive species of crayfish is of utmost importance given the plight of Europe’s native crayfish species. Many techniques have been applied to the growing problem with little success. Pheromones have been used to control terrestrial insect pests for a number of years with many success stories. The concept of applying pheromone control methods to the aquatic environment is by no means new, but has not been previously developed. This paper discusses the preliminary results from field trials testing traps baited with Pacifastacus leniusculus pheromones, and the potential application of the pheromones in controlling P. leniusculus populations.

  18. Predatory functional response and prey choice identify predation differences between native/invasive and parasitised/unparasitised crayfish.

    Science.gov (United States)

    Haddaway, Neal R; Wilcox, Ruth H; Heptonstall, Rachael E A; Griffiths, Hannah M; Mortimer, Robert J G; Christmas, Martin; Dunn, Alison M

    2012-01-01

    Invasive predators may change the structure of invaded communities through predation and competition with native species. In Europe, the invasive signal crayfish Pacifastacus leniusculus is excluding the native white clawed crayfish Austropotamobius pallipes. This study compared the predatory functional responses and prey choice of native and invasive crayfish and measured impacts of parasitism on the predatory strength of the native species. Invasive crayfish showed a higher (>10%) prey (Gammarus pulex) intake rate than (size matched) natives, reflecting a shorter (16%) prey handling time. The native crayfish also showed greater selection for crustacean prey over molluscs and bloodworm, whereas the invasive species was a more generalist predator. A. pallipes parasitised by the microsporidian parasite Thelohania contejeani showed a 30% reduction in prey intake. We suggest that this results from parasite-induced muscle damage, and this is supported by a reduced (38%) attack rate and increased (30%) prey handling time. Our results indicate that the per capita (i.e., functional response) difference between the species may contribute to success of the invader and extinction of the native species, as well as decreased biodiversity and biomass in invaded rivers. In addition, the reduced predatory strength of parasitized natives may impair their competitive abilities, facilitating exclusion by the invader.

  19. Differences in aggression, activity and boldness between native and introduced populations of an invasive crayfish

    Science.gov (United States)

    Pintor, L.M.; Sih, A.; Bauer, M.L.

    2008-01-01

    Aggressiveness, along with foraging voracity and boldness, are key behavioral mechanisms underlying the competitive displacement and invasion success of exotic species. However, do aggressiveness, voracity and boldness of the invader depend on the presence of an ecologically similar native competitor in the invaded community? We conducted four behavioral assays to compare aggression, foraging voracity, threat response and boldness to forage under predation risk of multiple populations of exotic signal crayfish Pacifastacus leniusculus across its native and invaded range with and without a native congener, the Shasta crayfish P. fortis. We predicted that signal crayfish from the invaded range and sympatric with a native congener (IRS) should be more aggressive to outcompete a close competitor than populations from the native range (NR) or invaded range and allopatric to a native congener (IRA). Furthermore, we predicted that IRS populations of signal crayfish should be more voracious, but less bold to forage under predation risk since native predators and prey likely possess appropriate behavioral responses to the invader. Contrary to our predictions, results indicated that IRA signal crayfish were more aggressive towards conspecifics and more voracious and active foragers, yet also bolder to forage under predation risk in comparison to NR and IRS populations, which did not differ in behavior. Higher aggression/voracity/ boldness was positively correlated with prey consumption rates, and hence potential impacts on prey. We suggest that the positive correlations between aggression/voracity/boldness are the result of an overall aggression syndrome. Results of stream surveys indicated that IRA streams have significantly lower prey biomass than in IRS streams, which may drive invading signal crayfish to be more aggressive/voracious/bold to acquire resources to establish a population. ?? 2008 The Authors.

  20. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species

    Directory of Open Access Journals (Sweden)

    D.M. Holdich

    2009-01-01

    Full Text Available Non-indigenous crayfish species (NICS in Europe now outnumber indigenous crayfish species (ICS 2:1, and it has been predicted that they may dominate completely in the next few decades unless something is done to protect them. Of the ten NICS introduced at least nine have become established in areas occupied by four of the five ICS. A decline in stocks of ICS has been recorded in many countries in the face of increasing populations of NICS. Most European countries retain at least one ICS but all are under threat from habitat loss, deteriorating water quality, overfishing, climate change, and most importantly from NICS and crayfish plague. The threat to ICS is so great in some countries that “ark”sanctuary sites are being established.The three most widely-spread NICS are the North American species: Pacifastacus leniusculus, Orconectes limosus and Procambarus clarkii. These can be considered as “Old NICS”, which were introduced before 1975, compared with the “New NICS”, which were introduced after 1980, such as the North American species: Orconectes immunis, Orconectes juvenilis, Orconectes virilis, Procambarus sp. and Procambarus acutus; and the Australian species: Cherax destructor and Cherax quadricarinatus, all of which have much narrower ranges in Europe. The North American species are potentially capable of acting as vectors of crayfish plague. Outbreaks of this disease occur regularly where there are high concentrations of vectors.In addition to the NICS currently established in the wild, a further threat exists through the aquarium trade, where many American and Australian species are available via the internet and in aquarist centres. Owners of such species may discard them into the freshwater environment when they grow too big as with some Cherax spp. and Orconectes spp., or multiply too frequently as with Procambarus sp. (a parthenogenetic species. A conceptual model is presented as a possible way forward for protecting the

  1. Can heat waves change the trophic role of the world's most invasive crayfish? Diet shifts in Procambarus clarkii.

    Science.gov (United States)

    Carreira, Bruno M; Segurado, Pedro; Laurila, Anssi; Rebelo, Rui

    2017-01-01

    In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red swamp crayfish, Procambarus clarkii. In laboratory experiments, we fed juvenile and adult crayfish on animal, plant or mixed diets and exposed them to a short or a long heat wave. We then measured crayfish survival, growth, body reserves and Fulton's condition index. Diet choices of the crayfish maintained on the mixed diet were estimated using stable isotopes (13C and 15N). The results suggest a decreased efficiency of carnivorous diets at higher temperatures, as juveniles fed on the animal diet were unable to maintain high growth rates in the long heat wave; and a decreased efficiency of herbivorous diets at lower temperatures, as juveniles in the cold accumulated less body reserves when fed on the plant diet. Heat wave treatments increased the assimilation of plant material, especially in juveniles, allowing them to sustain high growth rates in the long heat wave. Contrary to our expectations, crayfish performance decreased in the long heat wave, suggesting that Mediterranean summer heat waves may have negative effects on P. clarkii and that they are unlikely to boost its populations in this region. Although uncertain, it is possible that the greater assimilation of the plant diet resulted from changes in crayfish feeding preferences, raising the hypotheses that i) heat waves may change the predominant impacts of this keystone species and ii) that by altering species' trophic niches, climate change may alter the main impacts of invasive alien species.

  2. Can heat waves change the trophic role of the world's most invasive crayfish? Diet shifts in Procambarus clarkii.

    Directory of Open Access Journals (Sweden)

    Bruno M Carreira

    Full Text Available In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red swamp crayfish, Procambarus clarkii. In laboratory experiments, we fed juvenile and adult crayfish on animal, plant or mixed diets and exposed them to a short or a long heat wave. We then measured crayfish survival, growth, body reserves and Fulton's condition index. Diet choices of the crayfish maintained on the mixed diet were estimated using stable isotopes (13C and 15N. The results suggest a decreased efficiency of carnivorous diets at higher temperatures, as juveniles fed on the animal diet were unable to maintain high growth rates in the long heat wave; and a decreased efficiency of herbivorous diets at lower temperatures, as juveniles in the cold accumulated less body reserves when fed on the plant diet. Heat wave treatments increased the assimilation of plant material, especially in juveniles, allowing them to sustain high growth rates in the long heat wave. Contrary to our expectations, crayfish performance decreased in the long heat wave, suggesting that Mediterranean summer heat waves may have negative effects on P. clarkii and that they are unlikely to boost its populations in this region. Although uncertain, it is possible that the greater assimilation of the plant diet resulted from changes in crayfish feeding preferences, raising the hypotheses that i heat waves may change the predominant impacts of this keystone species and ii that by altering species' trophic niches, climate change may alter the main impacts of invasive alien species.

  3. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

    Science.gov (United States)

    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  4. Double blow: Alien crayfish infected with invasive temnocephalan in South African waters

    Directory of Open Access Journals (Sweden)

    Louis du Preez

    2013-09-01

    Full Text Available Trade in live, freshwater crayfish for ornamental markets, as well as for aquaculture, has grown rapidly and has become the major pathway for the introduction of non-indigenous crayfish species to several countries worldwide. Here we report on the first record of the Australian "redclaw" Cherax quadracarinatus in the natural waters of a game reserve in South Africa. To compound the situation, these redclaw crayfish were infected with a non-indigenous temnocephalan flatworm parasite. Both crayfish and temnocephalan were in full breeding condition, with young. Further spreading of this crayfish to the subtropical, water-rich, northern KwaZulu-Natal Province of South Africa and southern Mozambique is predicted. Not only might the crayfish compete with indigenous aquatic invertebrates but the non-host-specific temnocephalan might transfer to local decapods, such as freshwater crabs.

  5. Invasion of an occupied niche by the crayfish Orconectes rusticus: potential importance of growth and mortality.

    Science.gov (United States)

    Hill, Anna M; Sinars, Damon M; Lodge, David M

    1993-06-01

    We are exploring mechanisms of an invasion that contradicts the oft-cited generalization that species invade vacant niches. In northern Wisconsin lakes, the introduced crayfish Orconectes rusticus is replacing two ecologically similar resident congeners, O. virilis and O. propinquus. In laboratory experiments, we compared growth and mortality of individually maintained crayfish offered one of five ad libitum diets: invertebrates, macrophytes, dentritus, periphyton or all items combined. Mortality was highest for O. virilis and lowest for O. rusticus. Macrophyte diets yielded the highest mortality. All three species grew best on invertebrate and combination diets but grew little or not at all on diets of periphyton, detritus or macrophytes. O. rusticus and O. virilis grew more than O. propinquus. O. rusticus grew more quickly and/or was better able to survive overall than its congeners. Therefore, O. rusticus would probably have advantages over O. virilis and O. propinquus in competitive interactions, reproductive success and avoiding size-selective fish predation. Subtle interspecific differences may interact strongly with other ecological factors and contribute to the displacement of resident species from a well-occupied niche.

  6. Trapping for invasive crayfish: comparisons of efficacy and selectivity of baited traps versus novel artificial refuge traps

    Directory of Open Access Journals (Sweden)

    Green Nicky

    2018-01-01

    Full Text Available Non-native crayfish can dominate the invertebrate biomass of invaded freshwaters, with their high ecological impacts resulting in their populations being controlled by numerous methods, especially trapping. Although baited funnel traps (BTs are commonly used, they tend to be selective in mainly catching large-bodied males. Here, the efficacy and selectivity of BTs were tested against an alternative trapping method based on artificial refuges (ARTs that comprised of a metal base with several tubes (refuges attached. The target species was signal crayfish Pacifastacus leniusculus in an upland river in southwest England. Trapping was completed in April to October over two consecutive years. In total, 5897 crayfish were captured, with 87% captured in ARTs. Comparison of the catch per unit effort (CPUE between the trapping methods in the same 24 hour periods revealed significantly higher CPUE in ARTs than of BTs. ARTs fished for 6 consecutive days had higher catches than both methods over 24 hours. Whilst catches in BTs were significantly dominated by males (1.49M:1F, the sex ratio of catches in ARTs was 0.99M:1F. The mean carapace length of crayfish was also significantly larger in BTs (43.2 ± 0.6 mm than in ARTs (33.6 ± 0.2 mm. Thus, ARTs had higher CPUE over 24 hour and 6 day periods versus BTs and also captured a greater proportion of smaller and female individuals. These results indicate that when trapping methods are deployed for managing invasions, the use of ARTs removes substantial numbers of crayfish of both sexes and of varying body sizes.

  7. ROUNDTABLE SESSION 2B: NATIONAL INTERACTIONS BETWEEN NON-INDIGENOUS AND INDIGENOUS CRAYFISH SPECIES

    Directory of Open Access Journals (Sweden)

    GHERARDI F.

    2002-07-01

    Full Text Available The main object of the present essay is to summarise some aspects underlying the interactions between non-indigenous (NICS and indigenous (ICS crayfish species. The discussion has been also extended to the effects exercised by NICS on the natural habitats they occupy. While doing research on the dyads NICS/ICS, one starting point is to extrapolate common traits that make NICS good invaders from the analysis of their biology, ecology and ethology and the comparison with indigenous species. A subsequent step is to switch attention to the understanding of the characteristics that make ecosystems less vulnerable to invasions and then to analyse both the complex interactions of invaders and target communities and the negative and positive impacts exerted by NICS on the occupied habitats. Examples from Sweden, Britain, and Italy have shown that NICS can replace the native species by a combination of several interacting mechanisms. Besides the transmission of the crayfish plague fungus, mechanisms into action include mostly competitive interference, but also diverse life history traits, recruitment failure, differential susceptibility to predation, and reproductive interference. It has been claimed that invasion theory is full of rules of thumb that, having no precise predictive powers, are thus useless to guide reliable public policy. The solution of the prediction problem requires an in-depth study of every potential invader and target community, trespassing the boundaries among disciplines and having a look at crayfish as a whole and not a single entity. The expectation is thus the return to precise and clear empirical generalisations that can be most useful to develop management strategies.

  8. CRAYFISH PREDATION ON TADPOLES : A COMPARISON BETWEEN A NATIVE (AUSTROPOTAMOBIUS PALLIPES AND AN ALIEN SPECIES (PROCAMBARUS CLARKII.

    Directory of Open Access Journals (Sweden)

    GHERARDI F.

    2001-04-01

    Full Text Available In the laboratory, the motivation and/or ability to prey on anuran larvae (Bufo bufo, Rana kl. esculenta and R. italica were compared between a native European (Austropotamobius pallipes and an alien North American crayfish species (Procambarus clarkii. Both were skilled predators of tadpoles, adopting a sit-and-wait strategy. However, because P. clarkii displayed lower latency times in the presence of one of the three amphibians (Rana kl. esculenta here tested, the hypothesis is raised that invasive crayfish are more opportunistic predators and possibly faster in switching to different prey than those species they are displacing. From a conservation perspective, these preliminary results further emphasise the importance of studies centred on the invasion-displacement dichotomy.

  9. Short Note Invasive Australian crayfish Cherax quadricarinatus in ...

    African Journals Online (AJOL)

    Most crayfish were between 50 and 59.9 mm carapace length. Males (average 82.6 g) were significantly heavier than females (37.2 g) and males were larger in carapace length, carapace width, chela length and chela width. A feral population of C. quadricarinatus is now established in the Sanyati Basin. Possible modes of ...

  10. THE FRESHWATER CRAYFISH AUSTROPOTAMOBIUS PALLIPESIN SOUTH TYROL: HERITAGE SPECIES AND BIOINDICATOR

    Directory of Open Access Journals (Sweden)

    FÜREDER L.

    2003-04-01

    Full Text Available Rapid decline of crayfish in European freshwaters and continuing threat necessitate integrated actions in conservation and management of native crayfish populations. Besides biological reasons (diseases, plague, the impact of toxic and harmful substances (fertilisers, herbicides or wastewater effluents, habitat alteration or fragmentation have been responsible for their decline in some regions. The same is true for the region of South Tyrol, where compared to previous investigations, only 10 of a former total of 15 crayfish locations in the water bodies could be affirmed. Although two new populations of the non-indigenous Astacus astacus were detected, the native Austropotamobius pallipes continues to decline. While many investigations have focused accurately on causal coherences for the decline of native populations, the properties of crayfish facilitate to reverse the situation. In a few examples, the potential of Austropotamobius pallipes, the native crayfish in South Tyrol, as “surrogate species” for effective biological conservation is discussed. Given the various adequate attributes of freshwater crayfish as surrogate species (including indicator species, umbrella species and flagship species qualities, they may help to advance not only the crayfish situation itself but also freshwater ecosystem properties in general.

  11. Habitat and co-occurrence of native and invasive crayfish in the Pacific Northwest, USA

    Science.gov (United States)

    Pearl, Christopher A.; Adams, Michael J.; McCreary, Brome

    2013-01-01

    Biological invasions can have dramatic effects on freshwater ecosystems and introduced crayfish can be particularly impacting. We document crayfish distribution in three large hydrographic basins (Rogue, Umpqua, Willamette/Columbia) in the Pacific Northwest USA. We used occupancy analyses to investigate habitat relationships and evidence for displacement of native Pacifastacus leniusculus (Dana, 1852) by two invaders. We found invasive Procambarus clarkii (Girard, 1852), in 51 of 283 sites and in all three hydrographic basins. We found invasive Orconectes n. neglectus (Faxon, 1885) at 68% of sites in the Rogue basin and provide first documentation of their broad distribution in the Umpqua basin. We found P. clarkii in both lentic and lotic habitats, and it was positively associated with manmade sites. P. leniusculus was positively associated with lotic habitats and negatively related to manmade sites. In the Rogue and Umpqua basins, O. n. neglectus and P. leniusculus were similar in their habitat associations. We did not find a negative relationship in site occupancy between O. n. neglectus and P. leniusculus. Our data suggest that P. clarkii has potential to locally displace P. leniusculus. There is still time for preventive measures to limit the spread of the invasive crayfish in this region.

  12. Habitat use and population structure of the invasive red swamp crayfish Procambarus clarkii (Girard, 1852 in a protected area in northern Italy

    Directory of Open Access Journals (Sweden)

    Donato Roberta

    2018-01-01

    Full Text Available The red swamp crayfish Procambarus clarkii is one of the most invasive alien species in Europe and included in the list of invasive species of Union concern. We describe for the first time some life-history traits of a red swamp crayfish population in the Nature Reserve of the Lago di Candia (Italy. We investigated (1 preferences of this species for specific environmental features on the banks of the lake, and (2 differences in size, sex ratio, and condition index between individuals caught in lake and marsh. Moreover, we compared sampling effort and the features of individuals caught in the lake, for two sampling seasons in 2014 and 2015. Findings indicated that the population was well established, and the marsh seemed to have better conditions for growth of individuals than the lake. Accordingly, continuity of riparian vegetation, opportunity to dig burrows, and trophic resource availability seems to facilitate the proliferation of the crayfish in the lake. Our study demonstrated that massive removal efforts over the whole active period of the species and more than one year of trapping are necessary to increase the controlling activities' success. This study could have important implications for further population management projects directed at biodiversity conservation in the area.

  13. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii) in China from Mitochondrial Control Region and Nuclear Intron Sequences

    Science.gov (United States)

    Li, Yanhe; Guo, Xianwu; Chen, Liping; Bai, Xiaohui; Wei, Xinlan; Zhou, Xiaoyun; Huang, Songqian; Wang, Weimin

    2015-01-01

    Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC) in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA) were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China. PMID:26132567

  14. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii in China from Mitochondrial Control Region and Nuclear Intron Sequences

    Directory of Open Access Journals (Sweden)

    Yanhe Li

    2015-06-01

    Full Text Available Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China.

  15. First record of the invasive Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868 in the Crocodile River, Kruger National Park, South Africa

    Directory of Open Access Journals (Sweden)

    Robin M. Petersen

    2017-03-01

    Full Text Available The redclaw crayfish Cherax quadricarinatus (von Martens, 1868, a robust freshwater crayfish native to Australia and Papua New Guinea, has now been recorded from the Kruger National Park (KNP. Previously absent from the Crocodile River, SAN Parks received a report in February 2016 of redclaw crayfish below the Van Graan Dam on the border of the KNP. Here, we provide evidence of the presence of redclaw crayfish in the Crocodile River. A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the KNP and the Komati Catchment. The negative impacts of global crayfish introductions justify efforts to discourage further introductions and prevent their secondary spread. Conservation implications: A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the Kruger National Park and the Komati Catchment.

  16. Status and management of noble crayfish Astacus astacus in Estonia

    Directory of Open Access Journals (Sweden)

    T. Paaver

    2009-01-01

    Full Text Available Noble crayfish Astacus astacus (L. is an indigenous and the only crayfish species in Estonia. It is potentially endangered by invasion of alien species, diseases and habitat deterioration but does not have legal protected status and is fished only for recreational purpose. Crayfish Working Group of Ministry of Environment and Department of Aquaculture of the Estonian University of Life Sciences have developed crayfish conservation and management plan. Since 1994 standardized test fishing with traps (which catch only crayfish over 7 cm TL has been carried out and database of these fishings shows, that crayfish is dwelling in more than 255 sites in the lakes, rivers, streams, artificial reservoirs. In 52% of monitored sites populations are weak, catch per trap night is below 1 specimen. Exceptionally rich is the stock on the island Saaremaa, where in 59% of populations catch per trap night is over 4 and can reach 50. Licensed recreational catch is allowed in regions, where monitoring data show good status of crayfish stock. It is not allowed to sell the crayfish caught on recreational license. Crayfishing season is limited with August, size limit in recreational fishery is 11 cm TL. There are 10 operating crayfish farms and 15 are under construction. The farms produce yearly around 1000 kg of commercial size crayfish for export to Finland. Over 200000 juveniles are produced for restocking yearly. Restocking projects e.g. restoration of populations, which have been lost because of plague have been successful. The main threat factor is crayfish plague. In 2006–2007 it destroyed the stock of crayfish farms of companies Veteko, Pähkla, Astacus and wild population of Põduste river on the island Saaremaa.

  17. Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales

    Science.gov (United States)

    Nolen, Matthew S.; Magoulick, Daniel D.; DiStefano, Robert J.; Imhoff, Emily M.; Wagner, Brian K.

    2014-01-01

    Crayfishes and other freshwater aquatic fauna are particularly at risk globally due to anthropogenic demand, manipulation and exploitation of freshwater resources and yet are often understudied. The Ozark faunal region of Missouri and Arkansas harbours a high level of aquatic biological diversity, especially in regard to endemic crayfishes. Three such endemics, Orconectes eupunctus,Orconectes marchandi and Cambarus hubbsi, are threatened by limited natural distribution and the invasions of Orconectes neglectus.

  18. Tracking the invasion of the red swamp crayfish Procambarus clarkii (Girard, 1852 (Decapoda Cambaridae in Sicily: a “citizen science” approach

    Directory of Open Access Journals (Sweden)

    Francesco Paolo Faraone

    2017-11-01

    Full Text Available The first record of the red swamp crayfish in Sicily dates back to 2003 and, since then, the species seemed to be confined to a few localities in western Sicily. A small “citizen science” project carried out from November 2016 onwards led to the creation of the “Sicilian Procambarus working group” (SPwg, which aims at monitoring the distribution and impact of the species in Sicily. To date, the SPwg found the red swamp crayfish in five new sites on the island, thus doubling the number of local sites of occurrence. The new Procambarus clarkii sites lie in different river basins, some of them located several hundred kilometres from the invaded areas known to date, suggesting the existence of multiple independent releases of the species in the wild. The need of better informing the local population on the risks exerted by invasive species on biological diversity, and of carefully monitoring the impact of P. clarkii on the Sicilian inland water biota is briefly stressed.

  19. Mitochondrial cytochrome oxidase I gene analysis indicates a restricted genetic background in Finnish noble crayfish (Astacus astacus stocks

    Directory of Open Access Journals (Sweden)

    Makkonen J.

    2015-01-01

    Full Text Available The IUCN Red List indexes the noble crayfish (Astacus astacus as vulnerable, with a declining population trend. The main threats to the species are the crayfish plague caused by the oomycete Aphanomyces astaci and the introduced North American crayfish that act as the carriers of this disease. In Finland, the noble crayfish is considered as a native species, which original distribution area covers the southern part of the country, but the species distribution has been dispersed to cover almost the whole country. The aim of this study was to survey the genetic diversity among the Finnish noble crayfish populations. The mitochondrial cytochrome oxidase I (COI-gene was sequenced from 742 individuals representing 59 populations from Finland and Estonia. As a result, only a single haplotype was found. Based on these results, the genetic diversity of noble crayfish in its Northern distribution range is remarkably low. The observed lack of variation can result from several mechanisms including small size of the founder population and the intense spreading of the species by manmade stockings. The restricted diversity can also be caused by eradication of the original populations due to crayfish plague epidemics and spreading of the invasive crayfish species carrying the crayfish plague. It is also possible that all contemporary Finnish noble crayfish populations originate from stockings with no variation in respect to COI-gene.

  20. Management of invasive species

    DEFF Research Database (Denmark)

    Schou, Jesper Sølver; Jensen, Frank

    impact of the establishment of this invasive species is a substantial increase in the number of allergy cases, which we use as a measure of the physical damage. As valuation methods, we use both the cost-of-illness method and the benefit transfer method to quantify the total gross benefits of the two...... policy actions. Based on the idea of an invasion function, we identify the total and average net benefit under both prevention and mitigation. For both policy actions, the total and average net benefits are significantly positive irrespective of the valuation method used; therefore, both prevention...... and mitigation are beneficial policy actions. However, the total and average net benefits under mitigation are larger than the benefits under prevention, implying that the former policy action is more beneficial. Despite this result, we conclude that prevention, not mitigation, shall be used because...

  1. The future of the indigenous freshwater crayfish Austropotamobius italicus in Basque Country streams: Is it possible to survive being an inconvenient species?

    Directory of Open Access Journals (Sweden)

    L. García-Arberas

    2009-01-01

    Full Text Available The white-clawed freshwater crayfish Austropotamobius italicus is listed as “vulnerable” in the Spanish Red List of threatened species, but local legislation varies among Spanish regions. Thus, while in some places the species is classified as “in risk of extinction” and various plans of conservation and restoration have been implemented, in the Basque Country and other regions the species is not listed. The distribution of the white-clawed crayfish in the province of Biscay (Basque Country was studied from 1993 to 2007 at more than 600 sampling locations. Results show that 108 streams were inhabited by the native crayfish species A. italicus while 137 streams were inhabited by non-native signal crayfish Pacifastacus leniusculus or red-swamp crayfish Procambarus clarkii. The spread of non-native crayfish is not the only threat to the native species whose survival is also closely dependent on how watersheds are managed. Most A. italicus populations inhabit headwaters, where forestry activities are very important. The presence of native crayfish in heavily forested areas results in a conflict of interests and makes its conservation particularly difficult. We employed a SWOT analysis – an assessment and decision tool commonly used in marketing and business – to evaluate the situation of the native white-clawed crayfish in Biscay, a province characterized by very high demographic pressure. SWOT analysis has proved to be a useful diagnostic tool and can help develop better and more accurate management strategies for the conservation of native crayfish threatened by multiple stressors.

  2. Do environmental changes or juvenile competition act as mechanisms of species displacement in crayfishes?

    Science.gov (United States)

    Westhoff, Jacob T.; DiStefano, R.J.; Magoulick, D.D.

    2012-01-01

    The Big Creek Crayfish, Orconectes peruncus, is native to the St. Francis River drainage in Missouri, USA and is often absent where the introduced Woodland Crayfish, Orconectes hylas, has established. We performed a field experiment to determine whether effects of current abiotic conditions and interspecific competition with O. hylas were responsible for displacement of O. peruncus from parts of their former range. We examined growth and survival of juvenile male O. peruncus exposed to juvenile male O. hylas in enclosures at two sites in the former range of O. peruncus. Enclosures contained 8 (low density) or 16 individuals (high density) and had O. peruncus only (control) or both species (interspecific treatment). Juvenile O. peruncus were able to survive and grow in portions of their former range, implicating biotic versus abiotic factors in the displacement of O. peruncus. Survival rates of O. peruncus did not differ among treatments at either site. Orconectes peruncus showed significant growth in all treatments and interspecific effects were not greater than intraspecific effects on O. peruncus growth rates. High-density treatments showed significantly reduced O. peruncus growth rates compared to low-density treatments, except in Carver Creek interspecific treatments. When considered in the context of previous studies examining the effects of O. hylas on O. peruncus, results suggest that neither direct competition between juvenile males of the two species or abiotic change are responsible for the decreased range of O. peruncus. Additional research is required to determine the mechanism(s) driving the displacement of O. peruncus. ?? 2011 Springer Science+Business Media B.V.

  3. Quantifying the invasiveness of species

    Directory of Open Access Journals (Sweden)

    Robert Colautti

    2014-04-01

    Full Text Available The success of invasive species has been explained by two contrasting but non-exclusive views: (i intrinsic factors make some species inherently good invaders; (ii species become invasive as a result of extrinsic ecological and genetic influences such as release from natural enemies, hybridization or other novel ecological and evolutionary interactions. These viewpoints are rarely distinguished but hinge on distinct mechanisms leading to different management scenarios. To improve tests of these hypotheses of invasion success we introduce a simple mathematical framework to quantify the invasiveness of species along two axes: (i interspecific differences in performance among native and introduced species within a region, and (ii intraspecific differences between populations of a species in its native and introduced ranges. Applying these equations to a sample dataset of occurrences of 1,416 plant species across Europe, Argentina, and South Africa, we found that many species are common in their native range but become rare following introduction; only a few introduced species become more common. Biogeographical factors limiting spread (e.g. biotic resistance, time of invasion therefore appear more common than those promoting invasion (e.g. enemy release. Invasiveness, as measured by occurrence data, is better explained by inter-specific variation in invasion potential than biogeographical changes in performance. We discuss how applying these comparisons to more detailed performance data would improve hypothesis testing in invasion biology and potentially lead to more efficient management strategies.

  4. Water chemistry and endangered white-clawed Crayfish: a literature review and field study of water chemistry association in Austropotamobius pallipes

    Directory of Open Access Journals (Sweden)

    Haddaway N.R.

    2015-01-01

    Full Text Available Populations of the endangered white-clawed crayfish (Austropotamobius pallipes have rapidly declined in distribution and density in recent decades as a result of invasive crayfish, disease and habitat degradation. The species is thought to be particularly sensitive to water chemistry, and has been proposed as a bio-indicator of water quality. Here we detail the results of a systematic review of the literature regarding the chemistry of waterbodies inhabited by white-clawed crayfish, along with a wide-scale field study of the chemistry of crayfish-inhabited waterbodies in the UK. We use these data to examine potentially significant variables influencing crayfish distribution. Several variables appear to have thresholds that affect crayfish distribution; crayfish presence was associated with high dissolved oxygen, low conductivity, ammonium, sodium, and phosphate, and to a lesser extent low sulphate, nitrate, and total suspended solids. Some variables (magnesium, potassium, sodium, sulphate, nitrate, and total suspended solids may be tolerated at moderate to high concentrations in isolation (indicated by the presence of some populations in high levels of these variables, but suites of chemical conditions may act synergistically in situ and must be considered together. Recent efforts to conserve white-clawed crayfish have included relocations to Ark Sites; novel protected habitats with reduced risk of the introduction of disease, invasive crayfish and habitat degradation. We use our findings to propose the first detailed guidelines for common water chemistry variables of potential Ark Sites for the conservation of the species throughout its European range.

  5. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    Directory of Open Access Journals (Sweden)

    Britton J. Robert

    2017-01-01

    Full Text Available The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish Pacifastacus leniusculus only being prominent prey items in warmer months and amphibians in winter, revealing that non-fish resources were seasonally important dietary components. Reconstructed body lengths of prey revealed the only species present in diet >350 mm was pike Esox lucius. These dietary data thus provide important information for informing conservation conflicts between otters and fishery interests.

  6. Are rapid transitions between invasive and native species caused by alternative stable states, and does it matter?

    Science.gov (United States)

    Hansen, Gretchen J A; Ives, Anthony R; Vander Zanden, M Jake; Carpenter, Stephen R

    2013-10-01

    Rapid transitions in ecosystem structure, or regime shifts, are a hallmark of alternative stable states (ASS). However, regime shifts can occur even when feedbacks are not strong enough to cause ASS. We investigated the potential for ASS to explain transitions between dominance of an invasive species, rusty crayfish (Orconectes rusticus), and native sunfishes (Lepomis spp.) in northern Wisconsin (USA) lakes. A rapid transition from Lepomis to rusty crayfish dominance occurred as rusty crayfish invaded Trout Lake, and the reverse transition resulted from an eight-year experimental removal of rusty crayfish from Sparkling Lake. We fit a stage-structured population model of species interactions to 31 years of time-series data from each lake. The model identified water level as an important driver, with drought conditions reducing rusty crayfish recruitment and allowing Lepomis dominance. The maximum-likelihood parameter estimates of the negative interaction between rusty crayfish and Lepomis led to ASS in the model, where each species was capable of excluding the other within a narrow range of environmental conditions. However, uncertainty in parameter estimates made it impossible to exclude the potential that rapid transitions were caused by a simpler threshold response lacking alternative equilibria. Simulated forward and backward transitions between species dominance occurred at different environmental conditions (i.e., hysteresis), even when the parameters used for simulation did not predict ASS as a result of slow species responses to environmental drivers. Thus, ASS are possible, but by no means certain, explanations for rapid transitions in this system, and our results highlight the difficulties associated with distinguishing ASS from other types of threshold responses. However, whether regime shifts are caused by ASS may be relatively unimportant in this system, as the range of conditions over which transitions occur is narrow, and under most conditions, the

  7. Terrestrial animals as invasive species and as species at risk from invasions

    Science.gov (United States)

    Deborah M. Finch; Dean Pearson; Joseph Wunderle; Wayne Arendt

    2010-01-01

    Including terrestrial animal species in the invasive species strategy plan is an important step in invasive species management. Invasions by nonindigenous species threaten nearly 50 percent of imperiled native species in the United States and are the Nation's second leading cause of species endangerment. Invasion and conversion of native habitats by exotic species...

  8. Two new species of freshwater crayfish of the genus Faxonius (Decapoda: Cambaridae) from the Ozark Highlands of Arkansas and Missouri.

    Science.gov (United States)

    Fetzner, James W Jr; Taylor, Christopher A

    2018-03-22

    Two new species of freshwater crayfish are described from the Ozarks Plateau of northern Arkansas and southern Missouri. Both species are restricted to the mainstem of rocky streams that are at least fourth-order or greater in size. Recent genetic and morphological investigations of the coldwater crayfish, Faxonius eupunctus Williams, 1952, indicated that it was actually composed of several undescribed species. Faxonius eupunctus is herein restricted to just the Eleven Point River system. Faxonius roberti, new species is found in the mainstem of the Spring and Strawberry river systems in northern Arkansas. It differs from F. eupunctus by lacking a male Form-I gonopod with a distal spatulate mesial process, and presence of two spines on the dorsal side of the merus, where F. eupunctus typically has 1 spine. Faxonius wagneri, new species is known from a 54 mile (86 km) stretch of the Eleven Point River mainstem, ranging from just southeast of Greer, Missouri to just north of Birdell, Arkansas. Faxonius wagneri can be differentiated from both F. eupunctus and Faxonius roberti sp. nov. by using the male Form-I and Form-II gonopods, the shape of the chelae, and the female annulus ventralis. In F. wagneri, the terminal elements of the first pleopod are almost twice as long as those in F. eupunctus and F. roberti, with the tips of the appendage reaching the posterior base of the first perieopod when the abdomen is flexed forward, whereas, in the other two species, these elements only reach the base of the second pereiopod. The species also possesses two spines on the dorsal side of the merus of the first pereiopod, which helps distinguish it from F. eupunctus.

  9. Garden ponds as potential introduction pathway of ornamental crayfish

    Directory of Open Access Journals (Sweden)

    Patoka J.

    2014-01-01

    Full Text Available The private stocking of ornamental crayfish in garden ponds was discussed in previous studies, but there is a lack of detailed analysis for better understanding of this introduction pathway. The Czech Republic is one of leading EU countries in trade with ornamental crayfish and private garden ponds are popular among people. The crayfish keepers in the country were interviewed by self-administered questionnaire to gather data about principal characteristics of the keepers and detailed information about crayfish breeding that are of interest for conservation managers. Besides of releasing crayfish into garden ponds, alarming illegal behavior such as releasing of juvenile crayfish into the wild, and capturing of indigenous crayfish from wild populations, were registered. Therefore focusing on public education to increase awareness of possible unwanted consequences of crayfish release and introduction of an obligation to inform customers about hazardousness of non-indigenous crayfish species for retailers and wholesalers is recommended.

  10. 76 FR 68776 - Invasive Species Advisory Committee

    Science.gov (United States)

    2011-11-07

    ... broad array of issues related to preventing the introduction of invasive species and providing for their...-2012 Invasive Species National Management Plan. The meeting is open to the public. An orientation...

  11. 77 FR 23740 - Invasive Species Advisory Committee

    Science.gov (United States)

    2012-04-20

    ... broad array of issues related to preventing the introduction of invasive species and providing for their... both ecological and management contexts, will center on topics that: (1) Pertain to invasive species...

  12. Exponential increase of signal crayfish in running waters in Sweden – due to illegal introductions?

    Directory of Open Access Journals (Sweden)

    Bohman P.

    2011-07-01

    Full Text Available Sweden has only one indigenous species of crayfish, the noble crayfish (Astacus astacus, Fabricius. There has been a steady decline of noble crayfish populations in Sweden since 1907, mainly due to the crayfish plague. To substitute the noble crayfish fishery lost, the Swedish government launched a large-scale introduction of the signal crayfish (Pacifastacus leniusculus Dana. Today, the signal crayfish is regarded as a chronic carrier of the crayfish plague, and an expansion of the species may seriously threaten the noble crayfish. This paper examines the decrease of noble crayfish populations, and the concurrent expansion of signal crayfish in running waters. Data from the Swedish Electrofishing RegiSter (SERS was used. We found that in 1980–1984 the noble crayfish occurred in 4.5% of the studied river sections. In 2008–2009 the occurrences had decreased to 1.9%. In contrast, the signal crayfish had increased in occurrence, from 0.2% (1980–1984 to 11.8% in (2008–2009. We studied the number of stocking permits for signal crayfish introductions, and the available signal crayfish population from the open fishery in Lake Vättern, as possible causes of this expansion. A negative correlation between stocking permits and increased occurrence in streams, and a positive correlation between the availability of crayfish in Lake Vättern and the occurrence in streams was found. This suggests that the expansion of signal crayfish may be due to illegal introductions, further endangering the endemic noble crayfish.

  13. Signal crayfish as zoogeomorphic agents: diel patterns of fine sediment suspension in a crayfish-affected river and the implications for fine sediment fluxes and dynamics

    Science.gov (United States)

    Rice, Stephen; Johnson, Matthew; Reeds, Jake; Longstaff, Holly; Extence, Chris

    2013-04-01

    The signal crayfish (Pacifasticus leniusculus) is a formidable invasive species that has had a deleterious impact on native freshwater fauna across Europe. We contend that the impact of this animal extends beyond ecology into geomorphology and hypothesise that crayfish are significant agents of fine sediment recruitment and mobilisation, with potentially profound impacts on water quality, substrate quality and fine sediment fluxes. Building on pioneering work by colleagues at Queen Mary University, London this poster considers the role of crayfish in fine sediment suspension in a lowland, gravel-bed river. The hypothesis that nocturnal increases in crayfish activity are associated with a greater frequency of sediment suspension events and increases in ambient turbidity, is tested. Strong diel fluctuations in water turbidity were recorded at several sites on the Brampton Arm of the River Nene in England, a river heavily populated by signal crayfish, during August and September 2012. With the exception of three summer flood events, stage measurements during the same period were essentially flat, ruling out a hydraulic cause for overnight rises in turbidity. Water samples collected at midnight and at midday at one site confirm this diel pattern for suspended sediment concentration. Higher mean turbidity values overnight are associated with an increase in the magnitude and frequency of isolated turbidity spikes or events and this is consistent with crayfish nocturnalism. In particular, we suspect that turbidity events are caused by the construction and maintenenance of burrows and by interactions between crayfish and the river bed while foraging, fighting and avoiding each other. Tying the diel SSC signal directly to crayfish activity proved difficult, but several lines of argument presented here suggest that crayfish are the most likely cause of the diel pattern. These results provide substantial support for the idea that signal crayfish are important zoogeomorphic

  14. 75 FR 29359 - Invasive Species Advisory Committee

    Science.gov (United States)

    2010-05-25

    ... Council is co-chaired by the Secretary of the Interior, the Secretary of Agriculture, and the Secretary of... of the most invaded marine/coastal environments in the world, with over 50 invasive species that... development of state invasive species councils. DATES: Meeting of the Invasive Species Advisory Committee...

  15. Invasive Species Science Update (No. 7)

    Science.gov (United States)

    Dean Pearson; Yvette Ortega; Jack Butler

    2014-01-01

    Invasive Species Science Updates are designed to keep managers and other users up-to-date with recently completed and ongoing research by RMRS scientists, as well as highlight breaking news related to invasive species issues. The newsletter is produced by the RMRS Invasive Species Working Group (ISWG), which is a core group of scientists who volunteer to coordinate...

  16. Do invasive plant species alter soil health?

    Science.gov (United States)

    Invasive species may alter soil characteristics or interact with the soil microbial community to yield a competitive advantage. Our objectives were to determine: if invasive plant species alter soil properties important to soil health; and the long-term effects of invasive plant species on soil pro...

  17. The Invasive Species Forecasting System

    Science.gov (United States)

    Schnase, John; Most, Neal; Gill, Roger; Ma, Peter

    2011-01-01

    The Invasive Species Forecasting System (ISFS) provides computational support for the generic work processes found in many regional-scale ecosystem modeling applications. Decision support tools built using ISFS allow a user to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of management concern, such as a national park, monument, forest, or refuge. This type of decision product helps resource managers plan invasive species protection, monitoring, and control strategies for the lands they manage. Until now, scientists and resource managers have lacked the data-assembly and computing capabilities to produce these maps quickly and cost efficiently. ISFS focuses on regional-scale habitat suitability modeling for invasive terrestrial plants. ISFS s component architecture emphasizes simplicity and adaptability. Its core services can be easily adapted to produce model-based decision support tools tailored to particular parks, monuments, forests, refuges, and related management units. ISFS can be used to build standalone run-time tools that require no connection to the Internet, as well as fully Internet-based decision support applications. ISFS provides the core data structures, operating system interfaces, network interfaces, and inter-component constraints comprising the canonical workflow for habitat suitability modeling. The predictors, analysis methods, and geographic extents involved in any particular model run are elements of the user space and arbitrarily configurable by the user. ISFS provides small, lightweight, readily hardened core components of general utility. These components can be adapted to unanticipated uses, are tailorable, and require at most a loosely coupled, nonproprietary connection to the Web. Users can invoke capabilities from a command line; programmers can integrate ISFS's core components into more complex systems and services. Taken together, these

  18. CONSERVATION PROGRAMS THAT PROMOTE INVASIVE SPECIES

    Science.gov (United States)

    Invasive plant species are degrading the structure and function of ecosystems throughout the world. Although most state and federal conservation agencies in the U.S. attempt to reduce the impact of invasive species, some agency activities can contribute to the spread of invasive...

  19. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  20. Muddied waters: suspended sediment impacts on gill structure and aerobic scope in an endangered native and an invasive freshwater crayfish

    DEFF Research Database (Denmark)

    Rosewarne, P.J.; Svendsen, Jon Christian; Mortimer, R.J.G.

    2014-01-01

    Suspended sediment (SS) loadings in freshwater habitats have increased over the past century and SS is now a significant environmental stressor. Greater tolerance to environmental stressors has been proposed as a factor in the success of aquatic invasive species. Further, parasites may interact...

  1. Preliminary Data on the Ecological Requirements of the Invasive Spiny-Cheek Crayfish in the Lower Danube

    Directory of Open Access Journals (Sweden)

    Pîrvu Mălina

    2014-12-01

    Full Text Available Water quality and properties of the riverbed often shape the community structure of aquatic ecosystems, occasionally sustaining the expansion of non-native species. This study aims to provide preliminary data on the ecological preferences of the invasive species Orconectes limosus, its control, and the protection of the native stock is an European priority. In order to assess the species ability to colonize small river systems, relevant tributaries in the invaded Danube sector were monitored. Statistical test indicates a preference for deep and warm rivers, low water velocity and also high concentrations of calcium.

  2. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    OpenAIRE

    Britton, J.R.; Berry, M.; Sewell, S.; Lees, C.; Reading, P.

    2017-01-01

    The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish...

  3. REINTRODUCTION OF NOBLE CRAYFISH ASTACUS ASTACUS AFTER CRAYFISH PLAGUE IN NORWAY

    Directory of Open Access Journals (Sweden)

    TAUGBØL T.

    2004-01-01

    Full Text Available The Glomma and Halden watercourses in Norway were hit by crayfish plague in 1987 and 1989. Reintroduction of the noble crayfish started in 1989 in the Glomma and in 1995 in the Halden watercourse. Norway has especially good conditions for reintroduction of the native crayfish after crayfish plague, as there is no alien plague-carrying crayfish species in the country. In the Glomma watercourse, approx. 15 000 adult crayfish and 10 000 juveniles have been stocked while in the Halden watercourse the figures are 19 000 adults and 26 500 juveniles. All stocking sites were previously regarded as very good crayfish localities. Four years after stocking, natural recruitment was recorded at all adult crayfish stocking sites in the Glomma watercourse and at most sites in the Halden watercourse. Current crayfish density is, however, much lower than pre-plague densities even at the sites where population development has been in progress for more than 10 years. Extensive post-stocking movements were recorded among adult crayfish. Some sites seemed more suitable for settling, resulting in a great variation in CPUE between the different test-fishing sites. Juveniles seem more appropriate as stocking material if the goal is to re-establish a population in a particular area, due to their stationary behaviour, which seems to remain as they grow larger.

  4. The Impacts of flow alterations to crayfishes in Southeastern Oklahoma, with an emphasis on the mena crayfish (orconectes menae)

    Science.gov (United States)

    Brewer, Shannon K.; Dyer, Joseph J.

    2016-01-01

    Human activities can alter the environment to the point that it is unsuitable to the native species resulting in a loss of biodiversity. Ecologists understand the importance of biodiversity and the conservation of vulnerable species. Species that are narrowly endemic are considered to be particularly vulnerable because they often use specific habitats that are highly susceptible to human disturbance. The basic components of species conservation are 1) delineation of the spatial distribution of the species, 2) understanding how the species interacts with its environment, and 3) employing management strategies based on the ecology of the species. In this study, we investigated several crayfish species endemic to the Ouachita Mountains in Oklahoma and Arkansas. We established the spatial distributions (i.e., range) of the crayfish using Maximum Entropy species distribution modeling. We then investigated crayfish habitat use with quantitative sampling and a paired movement study. Finally, we evaluated the ability of crayfish to burrow under different environmental conditions in a controlled laboratory setting. Crayfish distribution at the landscape scale was largely driven by climate, geology and elevation. In general, the endemic crayfish in this study occurred above 300-m elevation where the geology was dominated by sandstone and shale, and rainfall totals were the highest compared to the rest of the study region. Our quantitative data indicated crayfish did not select for specific habitat types at the reach scale; however, crayfish appeared to continue to use shallow and dry habitat even as the streams dried. Movement by passive integrated transponder (PIT) tagged crayfish was highly variable but crayfish tended to burrow in response to drought rather than migrate to wet habitat. Controlled laboratory experiments revealed smaller substrate size (pebble) restricted crayfish burrowing more than larger substrates (cobble). We also found excess fine sediment restricted

  5. The Invasive Plant Species Education Guide

    Science.gov (United States)

    Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

    2010-01-01

    To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

  6. 76 FR 30955 - Invasive Species Advisory Committee

    Science.gov (United States)

    2011-05-27

    ... Commerce. The duty of the Council is to provide national leadership regarding invasive species issues... broad array of issues related to preventing the introduction of invasive species and providing for their... with Western-based scientists and practitioners on problems and potential solutions, as well as...

  7. Distribution of native and exotic branchiobdellidans (Annelida: Clitellata) on their respective crayfish hosts in northern Italy, with the first record of native Branchiobdella species on an exotic North American crayfish.

    OpenAIRE

    Joy N. RAYBURN; Giovanni B. DELMASTRO; Stuart R. GELDER

    1999-01-01

    Branchiobdellidans were found on crayfish at the 18 sites examined in northern Italy. At 15 of the sites the native crayfish, Austropotamobius pallipes, was collected and all supported specimens of Branchiobdella italica. A few specimens of B. parasita were found at only two of these sites and no specimens of B. hexodonta were observed during the survey. The North American Louisiana red swamp crayfish, Procambarus (Scapulicambarus) clarkii has been found in three additional sites around Carma...

  8. Quantifying the invasiveness of species

    Czech Academy of Sciences Publication Activity Database

    Colautti, R. I.; Parker, J. D.; Cadotte, M. W.; Pyšek, Petr; Brown, C. S.; Sax, D. F.; Richardson, D. M.

    2014-01-01

    Roč. 21, č. 1 (2014), s. 7-27 ISSN 1619-0033 R&D Projects: GA ČR(CZ) GAP505/11/1112; GA ČR(CZ) GAP504/11/1028 Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : biological invasions * biogeographical comparison * invasiveness Subject RIV: EH - Ecology, Behaviour

  9. Fort Collins Science Center: Invasive Species Science

    Science.gov (United States)

    Stohlgren, Tom

    2004-01-01

    Invasive, non-native species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like "biological wildfires," they can quickly spread, and they affect nearly all terrestrial and aquatic ecosystems. Invasive species have become the greatest environmental challenge of the 21st century in terms of economic, environmental, and human health costs, with an estimated impact in the U.S. of over $138 billion per year. Managers of Department of the Interior and other public and private lands and waters rank invasive species as their top resource management problem.

  10. Multiple mechanisms enable invasive species to suppress native species.

    Science.gov (United States)

    Bennett, Alison E; Thomsen, Meredith; Strauss, Sharon Y

    2011-07-01

    Invasive plants represent a significant threat to ecosystem biodiversity. To decrease the impacts of invasive species, a major scientific undertaking of the last few decades has been aimed at understanding the mechanisms that drive invasive plant success. Most studies and theories have focused on a single mechanism for predicting the success of invasive plants and therefore cannot provide insight as to the relative importance of multiple interactions in predicting invasive species' success. We examine four mechanisms that potentially contribute to the success of invasive velvetgrass Holcus lanatus: direct competition, indirect competition mediated by mammalian herbivores, interference competition via allelopathy, and indirect competition mediated by changes in the soil community. Using a combination of field and greenhouse approaches, we focus on the effects of H. lanatus on a common species in California coastal prairies, Erigeron glaucus, where the invasion is most intense. We found that H. lanatus had the strongest effects on E. glaucus via direct competition, but it also influenced the soil community in ways that feed back to negatively influence E. glaucus and other native species after H. lanatus removal. This approach provided evidence for multiple mechanisms contributing to negative effects of invasive species, and it identified when particular strategies were most likely to be important. These mechanisms can be applied to eradication of H. lanatus and conservation of California coastal prairie systems, and they illustrate the utility of an integrated set of experiments for determining the potential mechanisms of invasive species' success.

  11. Invasive Species Science Update (No. 10)

    Science.gov (United States)

    Justin Runyon

    2018-01-01

    In this issue, we cover new research on wide-ranging topics from the longterm effects of drought on competition between native and invasive plant species, to the effects of drought on pollinator visitation to invasive plants, to a novel use of insect pheromones to improve biocontrol of invasive saltcedar. There’s also big news to report in weed biocontrol: two new...

  12. The assessment of the habitat and water quality requirements of the stone crayfish (Austropotamobius torrentium and noble crayfish (Astacus astacus species in the rivers from the Anina Mountains (SW Romania

    Directory of Open Access Journals (Sweden)

    Pârvulescu L.

    2011-02-01

    Full Text Available The species Austropotamobius torrentium and Astacus astacus are two species known in the EU directives to require deeper understanding of their autecologic requirements before any sustainable conservation effort could be successfully applied. Therefore, the paper aims to analyze the occurrence of these two species of crayfish in the Anina Mountains (Romania in relation to several physical-chemical indicators measured on site. The results suggest that the anthropogenic impacts registered in some of the sampling sites (e.g. organic pollution and river bed modification might have triggered the disappearance of both species from the areas of the water sheds situated downstream villages and towns, deforestation sites and sewage treatment plants. The analysis suggest that both species might have similar ecologic requirements, with a BMWP score of 8 (out of a possible 10, therefore good indicators of pristine aquatic environments and with a possible toleration to pollution but only up to a moderate level. Nevertheless, the lack of cohabitation of the populations of both species at a local scale was discussed along with two possible explaining hypotheses: behavioral exclusion or different times and/or modalities of dispersal history.

  13. Distribution of native and exotic branchiobdellidans (Annelida: Clitellata on their respective crayfish hosts in northern Italy, with the first record of native Branchiobdella species on an exotic North American crayfish.

    Directory of Open Access Journals (Sweden)

    Joy N. RAYBURN

    1999-02-01

    Full Text Available Branchiobdellidans were found on crayfish at the 18 sites examined in northern Italy. At 15 of the sites the native crayfish, Austropotamobius pallipes, was collected and all supported specimens of Branchiobdella italica. A few specimens of B. parasita were found at only two of these sites and no specimens of B. hexodonta were observed during the survey. The North American Louisiana red swamp crayfish, Procambarus (Scapulicambarus clarkii has been found in three additional sites around Carmagnola, south of Torino. The exotic Cambarincola mesochoreus was recovered from red crayfish at two sites. However, no specimens of C. mesochoreus were found at the third site, but specimens B. italica and B. parasita were identified. This is the first record of native Branchiobdella spp. on an exotic and wild crayfish in northern Italy.

  14. Alien invasive species and international trade

    Science.gov (United States)

    Emergency control measures for invasive species often rely on use of pesticides and other destructive practices. Public concern about pesticide contamination of the ground water and the environment has lead to increased restrictions on the use of pesticides for control of many destructive invasive ...

  15. Plant invasions: Merging the concepts of species invasiveness and community invasibility

    Czech Academy of Sciences Publication Activity Database

    Richardson, D. M.; Pyšek, Petr

    2006-01-01

    Roč. 30, č. 3 (2006), s. 409-431 ISSN 0309-1333 Institutional research plan: CEZ:AV0Z60050516 Keywords : plant invasions * species invasiveness * community invasibility Subject RIV: EF - Botanics Impact factor: 1.278, year: 2006

  16. Invasive Species Science Branch: research and management tools for controlling invasive species

    Science.gov (United States)

    Reed, Robert N.; Walters, Katie D.

    2015-01-01

    Invasive, nonnative species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like “biological wildfires,” they can quickly spread and affect nearly all terrestrial and aquatic ecosystems. Invasive species have become one of the greatest environmental challenges of the 21st century in economic, environmental, and human health costs, with an estimated effect in the United States of more than $120 billion per year. Managers of the Department of the Interior and other public and private lands often rank invasive species as their top resource management problem. The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. To disseminate this information, branch scientists are developing platforms to share invasive species information with DOI cooperators, other agency partners, and the public. From these and other data, branch scientists are constructing models to understand and predict invasive species distributions for more effective management. The branch also has extensive herpetological and population biology expertise that is applied to harmful reptile invaders such as the Brown Treesnake on Guam and Burmese Python in Florida.

  17. Economics of Harmful Invasive Species: A Review

    Directory of Open Access Journals (Sweden)

    George Marbuah

    2014-07-01

    Full Text Available The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive species; single species and groups of species at different geographical scales. However, the estimated damage costs show large variation, from less than 1 million USD to costs corresponding to 12% of gross domestic product, depending on the methods employed, geographical scale, and scope with respect to inclusion of different species. Decisions regarding optimal management strategies, when to act in the invasion chain and which policy to choose, have received much less attention in earlier years, but have been subject to increasing research during the last decade. More difficult, but also more relevant policy issues have been raised, which concern the targeting in time and space of strategies under conditions of uncertainty. In particular, the weighting of costs and benefits from early detection and mitigation against the uncertain avoidance of damage with later control, when the precision in targeting species is typically greater is identified as a key challenge. The role of improved monitoring for detecting species and their spread and damage has been emphasized, but questions remain on how to achieve this in practice. This is in contrast to the relatively large body of literature on policies for mitigating dispersal by trade, which is regarded as one of the most important vectors for the spread of invasive species. On the other hand, the literature on how to mitigate established species, by control or adaptation, is much more scant. Studies evaluating causes for success or failure of policies against invasive in practice are in principal non-existing.

  18. Invasive species unchecked by climate - response

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Duarte, Carlos M.

    2012-01-01

    environments. This may be particularly true in the world's boreal oceans as melting sea ice facilitates new migratory passages between the Atlantic and Pacific Oceans. Moreover, as the ebb and flow of biodiversity intensifies under anthropogenic climate change, novel climates and communities of species......Hulme points out that observed rates of range expansion by invasive alien species are higher than the median speed of isotherm movement over the past 50 years, which in turn has outpaced the rates of climate-associated range changes of marine and terrestrial species. This is not surprising, given...... of climate-change-induced range shifts between native and alien species are meaningful only after the initial invasive spread has reached a stable range boundary. A focus on regions with high velocities of climate change, and on regions such as the tropics where novel thermal niches are being created, should...

  19. Invasive species in southern Nevada [Chapter 4

    Science.gov (United States)

    Mathew L. Brooks; Steven M. Ostoja; Jeanne C. Chambers

    2013-01-01

    Southern Nevada contains a wide range of topographies, elevations, and climatic zones emblematic of its position at the ecotone between the Mojave Desert, Great Basin, and Colorado Plateau ecoregions. These varied environmental conditions support a high degree of biological diversity (Chapter 1), but they also provide opportunities for a wide range of invasive species...

  20. Habitat associations of three crayfish endemic to the Ouachita Mountain Ecoregion

    Science.gov (United States)

    Dyer, Joseph J.; Brewer, Shannon K.

    2018-01-01

    Many crayfish are of conservation concern because of their use of unique habitats and often narrow ranges. In this study, we determined fine-scale habitat use by 3 crayfishes that are endemic to the Ouachita Mountains, in Oklahoma and Arkansas. We sampled Faxonius menae (Mena Crayfish), F. leptogonopodus (Little River Creek Crayfish), and Fallicambarus tenuis (Ouachita Mountain Crayfish) from wet and dry erosional channel units of 29 reaches within the Little River catchment. We compared channel-unit and microhabitat selection for each species. Crayfish of all species and life stages selected erosional channel units more often than depositional units, even though these sites were often dry. Accordingly, crayfish at all life stages typically selected the shallowest available microhabitats. Adult crayfish of all species and juvenile Little River Creek Crayfish selected patches of coarse substrate, and all crayfish tended to use the lowest amount of bedrock available. In general, we showed that these endemic crayfish used erosional channel units of streams, even when the channel units were dry. Conservation efforts that protect erosional channel units and mitigate actions that cause channel downcutting to bedrock would benefit these crayfish, particularly during harsh, summer drying periods.

  1. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding

    NARCIS (Netherlands)

    Ghahramanzadeh, R.; Esselink, G.; Kodde, L.P.; Duistermaat, H.; Valkenburg, van J.L.C.H.; Marashi, S.H.; Smulders, M.J.M.; Wiel, van de C.C.M.

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to

  2. Temporal variation in the prevalence of the crayfish plague pathogen, Aphanomyces astaci, in three Czech spiny-cheek crayfish populations

    Directory of Open Access Journals (Sweden)

    Matasová K.

    2011-06-01

    Full Text Available North American crayfish species are natural hosts of the crayfish plague pathogen Aphanomyces astaci. The spiny-cheek crayfish Orconectes limosus, widespread in Central Europe, is the main reservoir of A. astaci in Czech Republic. We tested if there are temporal changes in the prevalence of infected individuals (i.e., the proportion of individuals in which the pathogen is detected in spiny-cheek crayfish populations. Crayfish from three populations shown previously to be infected to different extents (high, intermediate and low, were repeatedly sampled in different years (2004–2010 and seasons. The presence of A. astaci in the soft abdominal crayfish cuticle was tested by specific amplification of the pathogen DNA. There was no substantial temporal variation in pathogen prevalence in the highly and very lowly infected populations. However, a significant long-term as well as seasonal decrease was found in the intermediately infected population. This decline could be related to a decrease in population density over the studied years, and to crayfish seasonal moulting, respectively. A reliable estimate of pathogen prevalence in American crayfish populations thus requires repeated monitoring over years, preferably during the same season before the main period of crayfish moulting.

  3. A meta-analysis of trait differences between invasive and non-invasive plant species

    OpenAIRE

    van Kleunen, Mark; Weber, Ewald; Fischer, Markus

    2010-01-01

    A major aim in ecology is identifying determinants of invasiveness. We performed a meta-analysis of 117 field or experimental-garden studies that measured pair-wise trait differences of a total of 125 invasive and 196 non-invasive plant species in the invasive range of the invasive species. We tested whether invasiveness is associated with performance-related traits (physiology, leaf-area allocation, shoot allocation, growth rate, size and fitness), and whether such associations depend on typ...

  4. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

    Science.gov (United States)

    Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. © 2012 Blackwell Publishing Ltd.

  5. Invasive Plant Species in the National Parks of Vietnam

    OpenAIRE

    Bernard Dell; Pham Quang Thu; Dang Thanh Tan

    2012-01-01

    The impact of invasive plant species in national parks and forests in Vietnam is undocumented and management plans have yet to be developed. Ten national parks, ranging from uncut to degraded forests located throughout Vietnam, were surveyed for invasive plant species. Transects were set up along roads, trails where local people access park areas, and also tracks through natural forest. Of 134 exotic weeds, 25 were classified as invasive species and the number of invasive species ranged from ...

  6. A Landscape Approach to Invasive Species Management.

    Directory of Open Access Journals (Sweden)

    Miguel Lurgi

    Full Text Available Biological invasions are not only a major threat to biodiversity, they also have major impacts on local economies and agricultural production systems. Once established, the connection of local populations into metapopulation networks facilitates dispersal at landscape scales, generating spatial dynamics that can impact the outcome of pest-management actions. Much planning goes into landscape-scale invasive species management. However, effective management requires knowledge on the interplay between metapopulation network topology and management actions. We address this knowledge gap using simulation models to explore the effectiveness of two common management strategies, applied across different extents and according to different rules for selecting target localities in metapopulations with different network topologies. These management actions are: (i general population reduction, and (ii reduction of an obligate resource. The reduction of an obligate resource was generally more efficient than population reduction for depleting populations at landscape scales. However, the way in which local populations are selected for management is important when the topology of the metapopulation is heterogeneous in terms of the distribution of connections among local populations. We tested these broad findings using real-world scenarios of European rabbits (Oryctolagus cuniculus infesting agricultural landscapes in Western Australia. Although management strategies targeting central populations were more effective in simulated heterogeneous metapopulation structures, no difference was observed in real-world metapopulation structures that are highly homogeneous. In large metapopulations with high proximity and connectivity of neighbouring populations, different spatial management strategies yield similar outcomes. Directly considering spatial attributes in pest-management actions will be most important for metapopulation networks with heterogeneously

  7. A Landscape Approach to Invasive Species Management.

    Science.gov (United States)

    Lurgi, Miguel; Wells, Konstans; Kennedy, Malcolm; Campbell, Susan; Fordham, Damien A

    2016-01-01

    Biological invasions are not only a major threat to biodiversity, they also have major impacts on local economies and agricultural production systems. Once established, the connection of local populations into metapopulation networks facilitates dispersal at landscape scales, generating spatial dynamics that can impact the outcome of pest-management actions. Much planning goes into landscape-scale invasive species management. However, effective management requires knowledge on the interplay between metapopulation network topology and management actions. We address this knowledge gap using simulation models to explore the effectiveness of two common management strategies, applied across different extents and according to different rules for selecting target localities in metapopulations with different network topologies. These management actions are: (i) general population reduction, and (ii) reduction of an obligate resource. The reduction of an obligate resource was generally more efficient than population reduction for depleting populations at landscape scales. However, the way in which local populations are selected for management is important when the topology of the metapopulation is heterogeneous in terms of the distribution of connections among local populations. We tested these broad findings using real-world scenarios of European rabbits (Oryctolagus cuniculus) infesting agricultural landscapes in Western Australia. Although management strategies targeting central populations were more effective in simulated heterogeneous metapopulation structures, no difference was observed in real-world metapopulation structures that are highly homogeneous. In large metapopulations with high proximity and connectivity of neighbouring populations, different spatial management strategies yield similar outcomes. Directly considering spatial attributes in pest-management actions will be most important for metapopulation networks with heterogeneously distributed links. Our

  8. Rocky Mountain Research Station invasive species visionary white paper

    Science.gov (United States)

    D. E. Pearson; M. Kim; J. Butler

    2011-01-01

    Invasive species represent one of the single greatest threats to natural ecosystems and the services they provide. Effectively addressing the invasive species problem requires management that is based on sound research. We provide an overview of recent and ongoing invasive species research conducted by Rocky Mountain Research Station scientists in the Intermountain...

  9. Optimal detection and control strategies for invasive species management

    Science.gov (United States)

    Shefali V. Mehta; Robert G. Haight; Frances R. Homans; Stephen Polasky; Robert C. Venette

    2007-01-01

    The increasing economic and environmental losses caused by non-native invasive species amplify the value of identifying and implementing optimal management options to prevent, detect, and control invasive species. Previous literature has focused largely on preventing introductions of invasive species and post-detection control activities; few have addressed the role of...

  10. Invasive species information networks: Collaboration at multiple scales for prevention, early detection, and rapid response to invasive alien species

    Science.gov (United States)

    Simpson, Annie; Jarnevich, Catherine S.; Madsen, John; Westbrooks, Randy G.; Fournier, Christine; Mehrhoff, Les; Browne, Michael; Graham, Jim; Sellers, Elizabeth A.

    2009-01-01

    Accurate analysis of present distributions and effective modeling of future distributions of invasive alien species (IAS) are both highly dependent on the availability and accessibility of occurrence data and natural history information about the species. Invasive alien species monitoring and detection networks (such as the Invasive Plant Atlas of New England and the Invasive Plant Atlas of the MidSouth) generate occurrence data at local and regional levels within the United States, which are shared through the US National Institute of Invasive Species Science. The Inter-American Biodiversity Information Network's Invasives Information Network (I3N), facilitates cooperation on sharing invasive species occurrence data throughout the Western Hemisphere. The I3N and other national and regional networks expose their data globally via the Global Invasive Species Information Network (GISIN). International and interdisciplinary cooperation on data sharing strengthens cooperation on strategies and responses to invasions. However, limitations to effective collaboration among invasive species networks leading to successful early detection and rapid response to invasive species include: lack of interoperability; data accessibility; funding; and technical expertise. This paper proposes various solutions to these obstacles at different geographic levels and briefly describes success stories from the invasive species information networks mentioned above. Using biological informatics to facilitate global information sharing is especially critical in invasive species science, as research has shown that one of the best indicators of the invasiveness of a species is whether it has been invasive elsewhere. Data must also be shared across disciplines because natural history information (e.g. diet, predators, habitat requirements, etc.) about a species in its native range is vital for effective prevention, detection, and rapid response to an invasion. Finally, it has been our

  11. DISTRIBUTION OF CRAYFISH IN EUROPE AND SOME ADJOINING COUNTRIES

    Directory of Open Access Journals (Sweden)

    HOLDICH D. M.

    2002-07-01

    Full Text Available The distribution of crayfish in Europe is examined using information from a variety of sources mainly for the last two decades. All European countries have at least one indigenous crayfish species (ICS, many with large stocks, and most countries in Western Europe have at least one non-indigenous crayfish species (NICS. Some species termed indigenous in certain countries may have been introduced in relatively recent times. However, the meaning of the term indigenous (native varies between countries. NICS continue to expand their ranges and present a continued threat to ICS through competition and transmission of diseases, notably crayfish plague. The current high level of interest in crayfish means that many countries are monitoring their crayfish situation and, where necessary, taking steps to renew stocks of threatened indigenous species, some of which are apparently on the verge of extinction. A more regular monitoring programme for European crayfish as a whole is needed if the demise of indigenous species is to be prevented.

  12. The stock of invasive insect species and its economic determinants.

    Science.gov (United States)

    Hlasny, Vladimir

    2011-06-01

    Invasions of nonindigenous organisms have long been linked to trade, but the contribution of individual trade pathways remains poorly understood, because species are not observed immediately upon arrival and the number of species arriving annually is unknown. Species interception records may count both new arrivals and species long introduced. Furthermore, the stock of invasive insect species already present is unknown. In this study, a state-space model is used to infer the stock of detected as well as undetected invasive insect species established in the United States. A system of equations is estimated jointly to distinguish the patterns of introduction, identification, and eradication. Introductions of invasive species are modeled as dependent on the volume of trade and arrival of people. Identifications depend on the public efforts at invasive species research, as well as on the established stock of invasive species that remain undetected. Eradications of both detected and undetected invasive species depend on containment and quarantine efforts, as well as on the stock of all established invasive species. These patterns are estimated by fitting the predicted number of invasive species detections to the observed record in the North American Non-Indigenous Arthropod Database. The results indicate that agricultural imports are the most important pathway of introduction, followed by immigration of people. Expenditures by the U.S. Department of Agriculture and the Agricultural Research Service are found to explain the species identification record well. Between three and 38 invasive insect species are estimated to be established in the United States undetected.

  13. New pasture plants intensify invasive species risk.

    Science.gov (United States)

    Driscoll, Don A; Catford, Jane A; Barney, Jacob N; Hulme, Philip E; Inderjit; Martin, Tara G; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M; Riley, Sophie; Visser, Vernon

    2014-11-18

    Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks.

  14. MINIMISING LOSS OF CRAYFISH AND HABITATDURING WORKS ON WATERCOURSES

    Directory of Open Access Journals (Sweden)

    PEAY S.

    2003-04-01

    Full Text Available Works in watercourses with white-clawed crayfish Austropotamobius pallipes cause temporary or permanent loss of habitat and crayfish. Past modifications can also leave waterbodies unfavourable for crayfish, but sometimes there is scope to improve them. Mitigation measures can reduce the impact and reinstate or even improve habitat. Various case studies show measures used during engineering works and some of the problems. Good planning and supervision are vital. The big issues at river and catchment scales (non-indigenous crayfish, disease, water quality and landuse may be higher priorities than provision of habitat at site or reach level; e.g. fencing in pastures improves riparian areas for crayfish and other species. If necessary, there are various options for natural and artificial refuges, but their success depends on flow characteristics, substrate and accessibility. Microhabitat can make the difference between success and failure.

  15. Comparative anatomy of invasive and non-invasive species in the ...

    African Journals Online (AJOL)

    The foliar and stem micromorphological study of the invasive and non-invasive species were undertaken using Light Microscope (LM). The occurrence of vessels in the pillar of the abundant sclerenchyma tissues are important component of the skeletal system in the invasive species. The prominent tiles of parenchymatous ...

  16. Five potential consequences of climate change for invasive species.

    Science.gov (United States)

    Hellmann, Jessica J; Byers, James E; Bierwagen, Britta G; Dukes, Jeffrey S

    2008-06-01

    Scientific and societal unknowns make it difficult to predict how global environmental changes such as climate change and biological invasions will affect ecological systems. In the long term, these changes may have interacting effects and compound the uncertainty associated with each individual driver. Nonetheless, invasive species are likely to respond in ways that should be qualitatively predictable, and some of these responses will be distinct from those of native counterparts. We used the stages of invasion known as the "invasion pathway" to identify 5 nonexclusive consequences of climate change for invasive species: (1) altered transport and introduction mechanisms, (2) establishment of new invasive species, (3) altered impact of existing invasive species, (4) altered distribution of existing invasive species, and (5) altered effectiveness of control strategies. We then used these consequences to identify testable hypotheses about the responses of invasive species to climate change and provide suggestions for invasive-species management plans. The 5 consequences also emphasize the need for enhanced environmental monitoring and expanded coordination among entities involved in invasive-species management.

  17. Depletion of heterogeneous source species pools predicts future invasion rates

    Science.gov (United States)

    Andrew M. Liebhold; Eckehard G. Brockerhoff; Mark Kimberley; Jacqueline Beggs

    2017-01-01

    Predicting how increasing rates of global trade will result in new establishments of potentially damaging invasive species is a question of critical importance to the development of national and international policies aimed at minimizing future invasions. Centuries of historical movement and establishment of invading species may have depleted the supply of species...

  18. Introduced and invasive cactus species: a global review

    Science.gov (United States)

    Novoa, Ana; Le Roux, Johannes J.; Robertson, Mark P.; Wilson, John R.U.; Richardson, David M.

    2015-01-01

    Understanding which species are introduced and become invasive, and why, are central questions in invasion science. Comparative studies on model taxa have provided important insights, but much more needs to be done to unravel the context dependencies of these findings. The cactus family (Cactaceae), one of the most popular horticultural plant groups, is an interesting case study. Hundreds of cactus species have been introduced outside their native ranges; a few of them are among the most damaging invasive plant species in the world. We reviewed the drivers of introductions and invasions in the family and seek insights that can be used to minimize future risks. We compiled a list of species in the family and determined which have been recorded as invasive. We also mapped current global distributions and modelled the potential global distributions based on distribution data of known invasive taxa. Finally, we identified whether invasiveness is phylogenetically clustered for cacti and whether particular traits are correlated with invasiveness. Only 57 of the 1922 cactus species recognized in this treatment have been recorded as invasive. There are three invasion hotspots: South Africa (35 invasive species recorded), Australia (26 species) and Spain (24 species). However, there are large areas of the world with climates suitable for cacti that are at risk of future invasion—in particular, parts of China, eastern Asia and central Africa. The invasive taxa represent an interesting subset of the total species pool. There is a significant phylogenetic signal: invasive species occur in 2 of the 3 major phylogenetic clades and in 13 of the 130 genera. This phylogenetic signal is not driven by human preference, i.e. horticultural trade, but all invasive species are from 5 of the 12 cactus growth forms. Finally, invasive species tend to have significantly larger native ranges than non-invasive species, and none of the invasive species are of conservation concern in their

  19. Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

    Science.gov (United States)

    Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2014-03-01

    Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

  20. Dna c-values of 20 invasive alien species and 3 native species in south china

    OpenAIRE

    Gong Ni; Wang Yu-Tao; Björn Lars Olof; Li Shao-Shan

    2014-01-01

    Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lo...

  1. A synthetic phylogeny of freshwater crayfish: insights for conservation

    Science.gov (United States)

    Owen, Christopher L.; Bracken-Grissom, Heather; Stern, David; Crandall, Keith A.

    2015-01-01

    Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project (opentreeoflife.org) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts. PMID:25561670

  2. The risk of establishment of aquatic invasive species: joining invasibility and propagule pressure.

    Science.gov (United States)

    Leung, Brian; Mandrak, Nicholas E

    2007-10-22

    Invasive species are increasingly becoming a policy priority. This has spurred researchers and managers to try to estimate the risk of invasion. Conceptually, invasions are dependent both on the receiving environment (invasibility) and on the ability to reach these new areas (propagule pressure). However, analyses of risk typically examine only one or the other. Here, we develop and apply a joint model of invasion risk that simultaneously incorporates invasibility and propagule pressure. We present arguments that the behaviour of these two elements of risk differs substantially--propagule pressure is a function of time, whereas invasibility is not--and therefore have different management implications. Further, we use the well-studied zebra mussel (Dreissena polymorpha) to contrast predictions made using the joint model to those made by separate invasibility and propagule pressure models. We show that predictions of invasion progress as well as of the long-term invasion pattern are strongly affected by using a joint model.

  3. 77 FR 23494 - Invasive Species Advisory Committee; Request for Nominations

    Science.gov (United States)

    2012-04-19

    ... human health impacts that invasive species cause. NISC is Co-chaired by the Secretaries of the Interior... coordinated network to document, evaluate, and monitor impacts from invasive species; and facilitates... management and restoration; animal health protection; shipping, tourism, highways, and other transportation...

  4. 78 FR 9724 - Invasive Species Advisory Committee; Meetings

    Science.gov (United States)

    2013-02-11

    ..., on a broad array of issues related to preventing the introduction of invasive species and providing... outlined in the 2008-2012 National Invasive Species Management Plan. The meeting agenda is now available on... be no committee business conducted during the orientation session, which is closed to the public...

  5. Invasive Species Working Group: Research Summary and Expertise Directory

    Science.gov (United States)

    Jack Butler; Dean Pearson; Mee-Sook Kim

    2009-01-01

    Rocky Mountain Research Station (RMRS) personnel have scientific expertise in widely ranging disciplines and conduct multidisciplinary research on invasive species issues with emphasis in terrestrial and aquatic habitats throughout the Interior West, Great Plains, and related areas (fig. 1; Expertise Directory; appendix). RMRS invasive species research covers an array...

  6. Science priorities for reducing the threat of invasive species

    Science.gov (United States)

    E. A. Chornesky; A. M. Bartuska; G. H. Aplet; J. Cummings-Carlson; F. W. Davis; J. Eskow; D. R. Gordon; K. W. Gottschalk; R. A. Haack; A. J. Hansen; R. N. Mack; F. J. Rahel; M. A. Shannon; L. A. Wainger; T. B. Wigley

    2005-01-01

    Invasive species pose a major, yet poorly addressed, threat to sustainable forestry. Here we set forth an interdisciplinary science strategy of research, development, and applications to reduce this threat. To spur action by public and private entities that too often are slow, reluctant, or unable to act, we recommend (a) better integrating invasive species into...

  7. Predicting the dynamics of local adaptation in invasive species

    Science.gov (United States)

    An invasive plant species may restrict its spread to only one habitat, or, after some time, may continue to spread into a different, secondary, habitat. The question of whether evolution is required for an invasive species to spread from one habitat to another is currently hotly debated. In order fo...

  8. Invasive species in east Africa: current status for informed policy ...

    African Journals Online (AJOL)

    Invasive alien species are the second leading cause of biodiversity loss in the world today. A number of hypotheses have been advanced to explain the proliferation of invasive species. These hypotheses include deficiency of natural enemies in the introduced range, increased competitive ability, increased resource ...

  9. Dna c-values of 20 invasive alien species and 3 native species in south china

    Directory of Open Access Journals (Sweden)

    Gong Ni

    2014-01-01

    Full Text Available Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lowest DNA C-value among the perennials, indicating that native species with low nuclear content may also possess an invasive potential.

  10. Vision of a cyberinfrastructure for nonnative, invasive species management

    Science.gov (United States)

    2008-01-01

    Although the quantity of data on the location, status, and management of invasive species is ever increasing, invasive species data sets are often difficult to obtain and integrate. A cyberinfrastructure for such information could make these data available for Internet users. The data can be used to create regional watch lists, to send e-mail alerts when a new species enters a region, to construct models of species' current and future distributions, and to inform management. Although the exchange of environmental data over the Internet in the form of raster data is maturing, and the exchange of species occurrence data is developing quickly, there is room for improvement. In this article, we present a vision for a comprehensive invasive species cyberinfrastructure that is capable of accessing data effectively, creating models of invasive species spread, and distributing this information.

  11. A review of ecological interactions between crayfish and fish, indigenous and introduced

    Directory of Open Access Journals (Sweden)

    Reynolds J.D.

    2011-05-01

    Full Text Available Crayfish (decapods and fish are both long-lived large members of freshwater communities, often functioning as keystone species. This paper reviews interactions between these, with emphasis on the European context. Native crayfish and fish are in ecological balance, which may involve mutual predation, competition and sometimes habitat disturbance. This balance is disrupted by range extensions and translocations of native fish or crayfish into exotic situations. Some fish and crayfish have been translocated globally, chiefly from North America to other continents. Non-indigenous crayfish species (NICS may impact on native fish, just as introduced fish impact on indigenous crayfish species (ICS. Competition between ICS and NICS may result in making the former susceptible to various mechanisms of interaction with fish, indigenous or introduced. In Europe, long-established NICS – signals, spiny-cheek and red swamp crayfish – may occur in greater densities than ICS; they are more tolerant and aggressive and show more interactions with fish. More recent introductions, still restricted in distribution, have not yet received enough study for their impacts to be assessed. Interactions between fish and crayfish in North and South America, Madagascar and Australasia are also explored. Mechanisms of interaction between fish and crayfish include mutual predation, competition for food and spatial resources, food-web alteration and habitat modification. Resultant changes in communities and ecosystems may be physical or biotal, and affect both ecosystem services and exploitation potential.

  12. Soil modification by invasive plants: Effects on native and invasive species of mixed-grass prairies

    Science.gov (United States)

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2008-01-01

    Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.

  13. Invasive alien species – framework for the identification of invasive alien species of EU concern

    OpenAIRE

    Roy, Helen; Schonrogge, Karsten; Dean, Hannah; Peyton, Jodey; Branquart, Etienne; Vanderhoeven, Sonia; Copp, Gordon; Stebbing, Paul; Kenis, Marc; Rabitsch, Wolfgang; Essl, Franz; Schindler, Stefan; Brunel, Sarah; Kettunen, Marianne; Mazza, Leonardo

    2014-01-01

    Invasive alien species (IAS) are considered to be one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change (MEA 2005, GBO 2011). In recent years the European Commission (EC) has intensified their commitment to provide a comprehensive, problem-oriented, well-balanced and manageable solution to IAS in Europe. The text of a European Union (EU) Regulation is expected to be adopted soon. A core component of the Regulation is a list of “IAS o...

  14. UNDERSTANDING AND MANAGING BIODIVERSITY IN RELATION TO NATIVE CRAYFISH POPULATIONS IN EUROPE

    Directory of Open Access Journals (Sweden)

    GHERARDI F.

    2003-04-01

    Full Text Available The loss or diminution of European crayfish populations because of both habitat deterioration and competition with alien crayfish – also responsible for the dissemination of the crayfish plague – would reduce the biodiversity at the species level. The topic “What is meant by biodiversity?” in the context of native freshwater crayfish in Europe was discussed during the Kilkenny CRAYNET meeting in order to make the point about the varied meanings of biodiversity from genes and individuals to population levels.

  15. Placing invasive species management in a spatiotemporal context.

    Science.gov (United States)

    Baker, Christopher M; Bode, Michael

    2016-04-01

    Invasive species are a worldwide issue, both ecologically and economically. A large body of work focuses on various aspects of invasive species control, including how to allocate control efforts to eradicate an invasive population as cost effectively as possible: There are a diverse range of invasive species management problems, and past mathematical analyses generally focus on isolated examples, making it hard to identify and understand parallels between the different contexts. In this study, we use a single spatiotemporal model to tackle the problem of allocating control effort for invasive species when suppressing an island invasive species, and for long-term spatial suppression projects. Using feral cat suppression as an illustrative example, we identify the optimal resource allocation for island and mainland suppression projects. Our results demonstrate how using a single model to solve different problems reveals similar characteristics of the solutions in different scenarios. As well as illustrating the insights offered by linking problems through a spatiotemporal model, we also derive novel and practically applicable results for our case studies. For temporal suppression projects on islands, we find that lengthy projects are more cost effective and that rapid control projects are only economically cost effective when population growth rates are high or diminishing returns on control effort are low. When suppressing invasive species around conservation assets (e.g., national parks or exclusion fences), we find that the size of buffer zones should depend on the ratio of the species growth and spread rate.

  16. INVENTORY OF THE INVASIVE ALIE N PLANT SPECIES IN INDONESIA

    Directory of Open Access Journals (Sweden)

    SRI S UDARMIYATI T JITROSOEDIRDJO

    2005-01-01

    Full Text Available An inventory of the alien plant species in Indone sia based on the existing references and herbarium specimens concluded that 1936 alien plant species ar e found in Indonesia which belong to 187 families. Field studies should be done to get the complete figur es of alien plant species in Indonesia. Based on the existing figures of the plant species, the invasive alien plant species can be iden tified, followed by studies on the assessment of losses, biology, management and their possible utilizations. Alien plant species are imported to Indonesia for cultivation, collection of the botanical garden, as experimental plants or other curiosities. Aside from plants purposely imported, there are also introduced plant propagules conta-minating imported agricultural products. These alien plant species can be beneficial or have a potential of being invasive. The alien cultivated species consisted of 67% of the total number. More than half of the cultivated plants are ornamental plants. Some of th e species are naturalized or escaped from cultivation and become wild and invasive. Some other natura lized species, adapted well without any problems of invasion. There are 339 species or 17% of the species r ecorded as weeds. The highest record of weeds is found in the family of Poaceae (57 species, follo wed by Asteraceae (53 species and Cyperaceae (35 species. There are 6 families having more than 10 species of weeds: Amaranthaceae, Asteraceae, Cyperaceae, Euphorbiaceae, Poaceae, and Rubiaceae. Three families have more than 100 species: Asteraceae 162 species, Poaceae 120 species, and Papillionaceae 103 species. Five species of aquatic and 20 species of terrestrial plants considered as important alien plant species in Indonesia were identified and some of their distributions noted

  17. Towards Arctic Resource Governance of Marine Invasive Species

    DEFF Research Database (Denmark)

    Kourantidou, Melina; Kaiser, Brooks; Fernandez, Linda

    2015-01-01

    Scientific and policy-oriented publications highlighting the magnitude of uncertainty in the changing Arctic and the possibilities for effective regional governance are proliferating, yet it remains a challenging task to examine Arctic marine biodiversity. Limited scientific data are currently...... available. Through analysis of marine invasions in the Arctic, we work to identify and assess patterns in the knowledge gaps regarding invasive species in the Arctic that affect the ability to generate improved governance outcomes. These patterns are expected to depend on multiple aspects of scientific...... research into invasive species threats in the Arctic, including the ways in which known marine invasions are related to different stakeholder groups and existing disparate national and international experiences with invasive species. Stakeholdergroups include dominant industries (fishing, shipping, tourism...

  18. Risk assessment for invasive species produces net bioeconomic benefits.

    Science.gov (United States)

    Keller, Reuben P; Lodge, David M; Finnoff, David C

    2007-01-02

    International commerce in live organisms presents a policy challenge for trade globalization; sales of live organisms create wealth, but some nonindigenous species cause harm. To reduce damage, some countries have implemented species screening to limit the introduction of damaging species. Adoption of new risk assessment (RA) technologies has been slowed, however, by concerns that RA accuracy remains insufficient to produce positive net economic benefits. This concern arises because only a small proportion of all introduced species escape, spread, and cause harm (i.e., become invasive), so a RA will exclude many noninvasive species (which provide a net economic benefit) for every invasive species correctly identified. Here, we develop a simple cost:benefit bioeconomic framework to quantify the net benefits from applying species prescreening. Because invasive species are rarely eradicated, and their damages must therefore be borne for long periods, we have projected the value of RA over a suitable range of policy time horizons (10-500 years). We apply the model to the Australian plant quarantine program and show that this RA program produces positive net economic benefits over the range of reasonable assumptions. Because we use low estimates of the financial damage caused by invasive species and high estimates of the value of species in the ornamental trade, our results underestimate the net benefit of the Australian plant quarantine program. In addition, because plants have relatively low rates of invasion, applying screening protocols to animals would likely demonstrate even greater benefits.

  19. Digestive efficiency of indigenous and invasive avian species fed ...

    African Journals Online (AJOL)

    ... Knysna (Tauraco corythaix) and Purple-crested (Gallirex porphyreolophus) Turacos and invasive alien Rose-ringed Parakeets (Psittacula krameri) met their energy demands when fed fruits of four fleshyfruited invasive alien plant species: Solanum mauritianum, Cinnamomum camphora, Psidium guajava and Morus alba.

  20. Economic essays on marine invasive species and international fisheries agreements

    NARCIS (Netherlands)

    Walker, A.N.

    2016-01-01

    This thesis is divided into two parts, as explained in Chapter 1, which focus on different aspects of marine ecological change. Part A considers marine Invasive Alien Species (IAS), which are taxa introduced outside of their native range. The detrimental consequences of invasions for human

  1. Experiments on growth interactions between two invasive macrophyte species

    NARCIS (Netherlands)

    Barrat-Segretain, M-H.; Elger, A.F.

    2004-01-01

    The success of invasive species has been attributed to the ability to displace other species by direct competition. We studied growth and possible competition between the two macrophyte species Elodea nuttallii and E. canadensis, because the former has been observed to replace the latter in the

  2. Inventory of the Invasive Alien Plant Species in Indonesia

    OpenAIRE

    TJITROSOEDIRDJO, SRI SUDARMIYATI

    2005-01-01

    An inventory of the alien plant species in Indonesia based on the existing references and herbarium specimens concluded that 1936 alien plant species are found in Indonesia which belong to 187 families. Field studies should be done to get the complete figures of alien plant species in Indonesia. Based on the existing figures of the plant species, the invasive alien plant species can be identified, followed by studies on the assessment of losses, biology, management and their possible utilizat...

  3. First evidence of crayfish plaque agent in populations of the marbled caryfish (Procambarus fallux forma virginalis)

    NARCIS (Netherlands)

    Keller, N.S.; Pfeiffer, M.; Roessink, I.; Schulz, R.; Schrimpf, A.

    2014-01-01

    The introduction of non-indigenous species and associated diseases can cause declines in indigenous flora and fauna and threaten local biodiversity. The crayfish plague pathogen (Aphanomyces astaci), carried and transmitted by latent infected North American crayfish, can lead to high mortalities in

  4. Effects of nonindigenous invasive species on water quality and quantity

    Science.gov (United States)

    Frank H. McCormick; Glen C. Contreras; Sherri L. Johnson

    2010-01-01

    Physical and biological disruptions of aquatic systems caused by invasive species alter water quantity and water quality. Recent evidence suggests that water is a vector for the spread of Sudden Oak Death disease and Port-Orfordcedar root disease. Since the 1990s, the public has become increasingly aware of the presence of invasive species in the Nation’s waters. Media...

  5. Globally threatened vertebrates on islands with invasive species.

    Science.gov (United States)

    Spatz, Dena R; Zilliacus, Kelly M; Holmes, Nick D; Butchart, Stuart H M; Genovesi, Piero; Ceballos, Gerardo; Tershy, Bernie R; Croll, Donald A

    2017-10-01

    Global biodiversity loss is disproportionately rapid on islands, where invasive species are a major driver of extinctions. To inform conservation planning aimed at preventing extinctions, we identify the distribution and biogeographic patterns of highly threatened terrestrial vertebrates (classified by the International Union for Conservation of Nature) and invasive vertebrates on ~465,000 islands worldwide by conducting a comprehensive literature review and interviews with more than 500 experts. We found that 1189 highly threatened vertebrate species (319 amphibians, 282 reptiles, 296 birds, and 292 mammals) breed on 1288 islands. These taxa represent only 5% of Earth's terrestrial vertebrates and 41% of all highly threatened terrestrial vertebrates, which occur in vertebrates was available for 1030 islands (80% of islands with highly threatened vertebrates). Invasive vertebrates were absent from 24% of these islands, where biosecurity to prevent invasions is a critical management tool. On the 76% of islands where invasive vertebrates were present, management could benefit 39% of Earth's highly threatened vertebrates. Invasive mammals occurred in 97% of these islands, with Rattus sp. as the most common invasive vertebrate (78%; 609 islands). Our results provide an important baseline for identifying islands for invasive species eradication and other island conservation actions that reduce biodiversity loss.

  6. Different aspects of reproduction strategies in crayfish: A review

    Directory of Open Access Journals (Sweden)

    Yazicioglu B.

    2016-01-01

    Full Text Available Study of the reproductive strategy of crayfish species is of great importance in the current astacological world. Crayfish are among the largest freshwater invertebrates, and as keystone species, they are able to regulate the structure of the benthic fauna in the freshwaters, demonstrating different ecological strategies and life spans ranging up to 20+ years. In order to bring together the various pieces of information related to this issue, this overview of published scientific reports was conducted. The majority of crayfish species studied show sexual dimorphism, with approximately equal numbers of males and females. However, over some decades numerous observations have been made for a few species that may have different modes of reproduction, such as hermaphroditism or intersex (e.g. Cherax quadricarinatus, Samastacus spinifrons, Parastacus virilastacus and Pacifastacus leniusculus and parthenogenesis (only Procambarus fallax f. virginalis. A recent study showed a new case of parthenogenesis as apomictic parthenogenesis (only Orconectes limosus. In addition, there are many investigations into the reproduction biology of crayfish, including using eyestalk ablation or androgenic gland ablation under various lab conditions and hybridization under natural conditions (e.g. Astacus astacus X Astacus leptodactylus, Orconectes rusticus X Orconectes propinquus. There are also some chemical factors which could possibly affect the reproduction system of crayfish in the wild.

  7. Ecological niche transferability using invasive species as a case study.

    Directory of Open Access Journals (Sweden)

    Miguel Fernández

    Full Text Available Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.

  8. Near term climate projections for invasive species distributions

    Science.gov (United States)

    Jarnevich, C.S.; Stohlgren, T.J.

    2009-01-01

    Climate change and invasive species pose important conservation issues separately, and should be examined together. We used existing long term climate datasets for the US to project potential climate change into the future at a finer spatial and temporal resolution than the climate change scenarios generally available. These fine scale projections, along with new species distribution modeling techniques to forecast the potential extent of invasive species, can provide useful information to aide conservation and invasive species management efforts. We created habitat suitability maps for Pueraria montana (kudzu) under current climatic conditions and potential average conditions up to 30 years in the future. We examined how the potential distribution of this species will be affected by changing climate, and the management implications associated with these changes. Our models indicated that P. montana may increase its distribution particularly in the Northeast with climate change and may decrease in other areas. ?? 2008 Springer Science+Business Media B.V.

  9. Essential elements of online information networks on invasive alien species

    Science.gov (United States)

    Simpson, A.; Sellers, E.; Grosse, A.; Xie, Y.

    2006-01-01

    In order to be effective, information must be placed in the proper context and organized in a manner that is logical and (preferably) standardized. Recently, invasive alien species (IAS) scientists have begun to create online networks to share their information concerning IAS prevention and control. At a special networking session at the Beijing International Symposium on Biological Invasions, an online Eastern Asia-North American IAS Information Network (EA-NA Network) was proposed. To prepare for the development of this network, and to provide models for other regional collaborations, we compare four examples of global, regional, and national online IAS information networks: the Global Invasive Species Information Network, the Invasives Information Network of the Inter-American Biodiversity Information Network, the Chinese Species Information System, and the Invasive Species Information Node of the US National Biological Information Infrastructure. We conclude that IAS networks require a common goal, dedicated leaders, effective communication, and broad endorsement, in order to obtain sustainable, long-term funding and long-term stability. They need to start small, use the experience of other networks, partner with others, and showcase benefits. Global integration and synergy among invasive species networks will succeed with contributions from both the top-down and the bottom-up. ?? 2006 Springer.

  10. Pushing the envelope in genetic analysis of species invasion

    Science.gov (United States)

    Samuel A. Cushman

    2015-01-01

    How a species spreads once introduced into a new environment is a major question in landscape genetics. When the species in question is a potential disease vector, the findings are important not only for fundamental science, but can impact applied science and public health as well. In this issue of Molecular Ecology Medley et al. (2014) study, the invasion...

  11. Central-marginal population dynamics in species invasions

    Directory of Open Access Journals (Sweden)

    Qinfeng eGuo

    2014-06-01

    Full Text Available The species’ range limits and associated central-marginal (C-M; i.e., from species range center to margin population dynamics continue to draw increasing attention because of their importance for current emerging issues such as biotic invasions and epidemic diseases under global change. Previous studies have mainly focused on species borders and C-M process in natural settings for native species. More recently, growing efforts are devoted to examine the C-M patterns and process for invasive species partly due to their relatively short history, highly dynamic populations, and management implications. Here I examine recent findings and information gaps related to (1 the C-M population dynamics linked to species invasions, and (2 the possible effects of climate change and land use on the C-M patterns and processes. Unlike most native species that are relatively stable (some even having contracting populations or ranges, many invasive species are still spreading fast and form new distribution or abundance centers. Because of the strong nonlinearity of population demographic or vital rates (i.e. birth, death, immigration and emigration across the C-M gradients and the increased complexity of species ranges due to habitat fragmentation, multiple introductions, range-wide C-M comparisons and simulation involving multiple vital rates are needed in the future.

  12. Invasive Species - A Threat to the Homeland?

    Science.gov (United States)

    2003-04-07

    species of weeds, diseases and organisms on both my farm and the surrounding woodlands. Some of these species include soybean cyst nematode, soybean aphid ...natural enemies in their new environment. Parasites, pathogens , or predators that would inhibit or limit their spread are few or non-existent. In...tested, and fielded to control the genetically modified organism. Serums would be less effective, and diagnosis of human pathogens could change and

  13. Potential impacts of alien freshwater crayfish in South Africa | de ...

    African Journals Online (AJOL)

    The habitat preferences and life history characteristics of four alien species of freshwater crayfish (Cherax tenuimanus, C. destructor, C. quadricarinatus and Procambarus clarkii) are reviewed. The potential impact of these species on South African freshwater ecosystems is assessed and the desirability of allowing their ...

  14. GSD Update: What are invasive species? ... And do we really need to worry about them?

    Science.gov (United States)

    Catherine Dold

    2011-01-01

    Invasive species are the focus of the September 2011 issue of GSDUpdate: What Are Invasive Species? And Do We Really Need to Worry About Them? An invasive species is any species - non-native or native to a region - that could cause economic or ecological harm to an area. Invasives can be weeds, shrubs and trees, insects, mollusks, vertebrates and even microorganisms...

  15. Mechanistic species distribution modeling reveals a niche shift during invasion.

    Science.gov (United States)

    Chapman, Daniel S; Scalone, Romain; Štefanić, Edita; Bullock, James M

    2017-06-01

    Niche shifts of nonnative plants can occur when they colonize novel climatic conditions. However, the mechanistic basis for niche shifts during invasion is poorly understood and has rarely been captured within species distribution models. We quantified the consequence of between-population variation in phenology for invasion of common ragweed (Ambrosia artemisiifolia L.) across Europe. Ragweed is of serious concern because of its harmful effects as a crop weed and because of its impact on public health as a major aeroallergen. We developed a forward mechanistic species distribution model based on responses of ragweed development rates to temperature and photoperiod. The model was parameterized and validated from the literature and by reanalyzing data from a reciprocal common garden experiment in which native and invasive populations were grown within and beyond the current invaded range. It could therefore accommodate between-population variation in the physiological requirements for flowering, and predict the potentially invaded ranges of individual populations. Northern-origin populations that were established outside the generally accepted climate envelope of the species had lower thermal requirements for bud development, suggesting local adaptation of phenology had occurred during the invasion. The model predicts that this will extend the potentially invaded range northward and increase the average suitability across Europe by 90% in the current climate and 20% in the future climate. Therefore, trait variation observed at the population scale can trigger a climatic niche shift at the biogeographic scale. For ragweed, earlier flowering phenology in established northern populations could allow the species to spread beyond its current invasive range, substantially increasing its risk to agriculture and public health. Mechanistic species distribution models offer the possibility to represent niche shifts by varying the traits and niche responses of individual

  16. Chronic effects of an invasive species on an animal community.

    Science.gov (United States)

    Doody, J Sean; Rhind, David; Green, Brian; Castellano, Christina; McHenry, Colin; Clulow, Simon

    2017-08-01

    Invasive species can trigger trophic cascades in animal communities, but published cases involving their removal of top predators are extremely rare. An exception is the invasive cane toad (Rhinella marina) in Australia, which has caused severe population declines in monitor lizards, triggering trophic cascades that facilitated dramatic and sometimes unexpected increases in several prey of the predators, including smaller lizards, snakes, turtles, crocodiles, and birds. Persistence of isolated populations of these predators with a decades-long sympatry with toads suggests the possibility of recovery, but alternative explanations are possible. Confirming predator recovery requires longer-term study of populations with both baseline and immediate post-invasion densities. Previously, we quantified short-term impacts of invasive cane toads on animal communities over seven years at two sites in tropical Australia. Herein, we test the hypothesis that predators have begun to recover by repeating the study 12 yr after the initial toad invasion. The three predatory lizards that experienced 71-97% declines in the short-term study showed no sign of recovery, and indeed a worse fate: two of the three species were no longer detectable in 630 km of river surveys, suggesting local extirpation. Two mesopredators that had increased markedly in the short term due to these predator losses showed diverse responses in the medium term; a small lizard species increased by ~500%, while populations of a snake species showed little change. Our results indicate a system still in ecological turmoil, having not yet reached a "new equilibrium" more than a decade after the initial invasion; predator losses due to this toxic invasive species, and thus downstream effects, were not transient. Given that cane toads have proven too prolific to eradicate or control, we suggest that recovery of impacted predators must occur unassisted by evolutionary means: dispersal into extinction sites from

  17. A globally-distributed alien invasive species poses risks to United States imperiled species.

    Science.gov (United States)

    McClure, Meredith L; Burdett, Christopher L; Farnsworth, Matthew L; Sweeney, Steven J; Miller, Ryan S

    2018-03-28

    In the midst of Earth's sixth mass extinction event, non-native species are a driving factor in many imperiled species' declines. One of the most widespread and destructive alien invasive species in the world, wild pigs (Sus scrofa) threaten native species through predation, habitat destruction, competition, and disease transmission. We show that wild pigs co-occur with up to 87.2% of imperiled species in the contiguous U.S. identified as susceptible to their direct impacts, and we project increases in both the number of species at risk and the geographic extent of risks by 2025. Wild pigs may therefore present a severe threat to U.S. imperiled species, with serious implications for management of at-risk species throughout wild pigs' global distribution. We offer guidance for efficient allocation of research effort and conservation resources across species and regions using a simple approach that can be applied to wild pigs and other alien invasive species globally.

  18. Status, Impact and Management of Invasive Alien Species in Tanzania

    African Journals Online (AJOL)

    The study used three methodological approaches including documentary search, interviews with relevant stakeholders and limited field visits. Findings from the study have indicated that the awareness, trends, distribution and impacts of the invasive alien species in Tanzania are variable, and similarly are the management ...

  19. Factors affecting people's response to invasive species management

    Science.gov (United States)

    Paul H. Gobster

    2011-01-01

    Natural areas managers contend with an increasingly diverse array of invasive species in their mission to conserve the health and integrity of ecosystems under their charge. As users, nearby neighbours and de facto 'owners' of the lands where many significant natural areas reside, the public is often highly supportive of broad programme goals for management...

  20. Economics of Arctic Fisheries and Marine Invasive Species Part I

    DEFF Research Database (Denmark)

    Kourantidou, Melina

    Bioeconomics of Red King Crab in the Barents Sea involves the crab’s dual nature as invader and market commodity. We apply a spatial dynamic model to find the optimal joint management of international invasive species threats with historic management of the Red King Crab by Norway and Russia...

  1. 76 FR 32135 - National Forest System Invasive Species Management Policy

    Science.gov (United States)

    2011-06-03

    ... increase the amount of invasive species work planned and accomplished, increasing economic development opportunities and improving local economic stability, including job and contracting opportunities among small... determination of an economic, human health, or environmental threshold that indicates when a pest population is...

  2. The importance of education in managing invasive plant species

    Science.gov (United States)

    Invasive plant species can establish in diverse environments and with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheat grass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wet lands and Canada this...

  3. AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES

    Science.gov (United States)

    Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

  4. Effects of Climate Change on Aquatic Invasive Species and ...

    Science.gov (United States)

    This draft report reviews available literature on climate change effects on aquatic invasive species (AIS) and examines state level AIS management activities. This draft report assesses the state of the science of climate change effects on AIS and examines state level AIS management activities.

  5. Invasive species in southern Nevada [Chapter 4] (Executive Summary)

    Science.gov (United States)

    Matthew L. Brooks; Steven M. Ostoja; Jeanne C.. Chambers

    2013-01-01

    Southern Nevada contains a wide range of topographies, elevations, and climatic zones that are emblematic of its position at the ecotone between the Mojave Desert, Great Basin, and Colorado Plateau ecoregions. These varied environmental conditions support a high degree of biological diversity, but they also provide opportunities for a wide range of invasive species. In...

  6. Spatial management of invasive species : Pathways and policy options

    NARCIS (Netherlands)

    Sanchirico, James N.; Albers, Heidi J.; Fischer, Carolyn; Coleman, Conrad

    2010-01-01

    In addressing the problem of invasive species, decision makers have a variety of options, each targeting different aspects as it evolves over time and space. We develop a 2-region bioeconomic model that includes several transmission pathways that spread the invader. Within each region, inspections,

  7. Invasive species control in a one-dimensional metapopulation network

    NARCIS (Netherlands)

    Walker, A.N.; Poos, J.J.; Groeneveld, R.A.

    2015-01-01

    The growth and spread of established Invasive Alien Species (IAS) cause significant ecological and economic damages. Minimising the costs of controlling, and the damages from, IAS depends on the spatial dynamics and uncertainty regarding IAS spread. This study expands on existing modelling

  8. Decisionmaking under risk in invasive species management: risk management theory and applications

    Science.gov (United States)

    Shefali V. Mehta; Robert G. Haight; Frances R. Homans

    2010-01-01

    Invasive species management is closely entwined with the assessment and management of risk that arises from the inherently random nature of the invasion process. The theory and application of risk management for invasive species with an economic perspective is reviewed in this synthesis. Invasive species management can be delineated into three general categories:...

  9. A single ectomycorrhizal fungal species can enable a Pinus invasion.

    Science.gov (United States)

    Hayward, Jeremy; Horton, Thomas R; Pauchard, Aníbal; Nuñnez, Martin A

    2015-05-01

    Like all obligately ectomycorrhizal plants, pines require ectomycorrhizal fungal symbionts to complete their life cycle. Pines introduced into regions far from their native range are typically incompatible with local ectomycorrhizal fungi, and, when they invade, coinvade with fungi from their native range. While the identities and distributions of coinvasive fungal symbionts of pine invasions are poorly known, communities that have been studied are notably depauperate. However, it is not yet clear whether any number of fungal coinvaders is able to support a Pinaceae invasion, or whether very depauperate communities are unable to invade. Here, we ask whether there is evidence for a minimum species richness of fungal symbionts necessary to support a pine/ectomycorrhizal fungus coinvasion. We sampled a Pinus contorta invasion front near Coyhaique, Chile, using molecular barcoding to identify ectomycorrhizal fungi. We report that the site has a total richness of four species, and that many invasive trees appear to be supported by only a single ectomycorrhizal fungus, Suillus luteus. We conclude that a single ectomycorrhizal (ECM) fungus can suffice to enable a pine invasion.

  10. Conservation status of crayfishes of the United States and Canada

    Science.gov (United States)

    Christopher A. Taylor; Melvin L. Warren; J. F. Fitzpatrick; Horton H. Hobbs; Raymond F. Jezerinac; William L. Pflieger; Henry W. Robinson

    1996-01-01

    The American Fisheries Society (AFS) Endangered Species Committee herein provides a list of all crayfishes (families and Cambaridae) in the United States and Canada that includes state provincial distributions; a comprehensive review of the conservation status of all taxa; and references on biology, conservation, and...

  11. Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment.

    Science.gov (United States)

    Peng, Qian; Nunes, Luís M; Greenfield, Ben K; Dang, Fei; Zhong, Huan

    2016-03-01

    Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68-95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining >92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10(-5)) for both the median (ILTR=2.5×10(-5)) and 90th percentile (ILTR=1.8×10(-4)), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Invasive plant species: Inventory, mapping, and monitoring - A national strategy

    Science.gov (United States)

    Ludke, J. Larry; D'Erchia, Frank; Coffelt, Jan; Hanson, Leanne

    2002-01-01

    America is under siege by invasive species of plants and animals, and by diseases. The current environmental, economic, and health-related costs of invasive species could exceed $138 billion per year-more than all other natural disasters combined. Notorious examples include West Nile virus, Dutch elm disease, chestnut blight, and purple loose- strife in the Northeast; kudzu, Brazilian peppertree, water hyacinth, nutria, and fire ants in the Southeast; zebra mussels, leafy spurge, and Asian long-horn beetles in the Midwest; salt cedar, Russian olive, and Africanized bees in the Southwest; yellow star thistle, European wild oats, oak wilt disease, Asian clams, and white pine blister rust in California; cheatgrass, various knapweeds, and thistles in the Great Basin; whirling disease of salmonids in the Northwest; hundreds of invasive species from microbes to mammals in Hawaii; and the brown tree snake in Guam. Thousands of species from other countries are introduced intentionally or accidentally into the United States each year. Based on past experience, 10-15 percent can be expected to establish free-living populations and about 1 percent can be expected to cause significant impacts to ecosystems, native species, economic productivity, and (or) human health.

  13. Novel organisms: comparing invasive species, GMOs, and emerging pathogens.

    Science.gov (United States)

    Jeschke, Jonathan M; Keesing, Felicia; Ostfeld, Richard S

    2013-09-01

    Invasive species, range-expanding species, genetically modified organisms (GMOs), synthetic organisms, and emerging pathogens increasingly affect the human environment. We propose a framework that allows comparison of consecutive stages that such novel organisms go through. The framework provides a common terminology for novel organisms, facilitating knowledge exchange among researchers, managers, and policy makers that work on, or have to make effective decisions about, novel organisms. The framework also indicates that knowledge about the causes and consequences of stage transitions for the better studied novel organisms, such as invasive species, can be transferred to more poorly studied ones, such as GMOs and emerging pathogens. Finally, the framework advances understanding of how climate change can affect the establishment, spread, and impacts of novel organisms, and how biodiversity affects, and is affected by, novel organisms.

  14. Plant invasions in the Czech Republic: current state, introduction dynamics, invasive species and invaded habitats

    Czech Academy of Sciences Publication Activity Database

    Pyšek, Petr; Chytrý, M.; Pergl, Jan; Sádlo, Jiří; Wild, Jan

    2012-01-01

    Roč. 84, č. 3 (2012), s. 575-629 ISSN 0032-7786 R&D Projects: GA ČR(CZ) GAP504/11/1028 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : invasive species * invaded habitats * Czech Republic Subject RIV: EF - Botanics Impact factor: 2.833, year: 2012

  15. Seed bank survival of an invasive species, but not of two native species, declines with invasion.

    Science.gov (United States)

    Orrock, John L; Christopher, Cory C; Dutra, Humberto P

    2012-04-01

    Soil-borne seed pathogens may play an important role in either hindering or facilitating the spread of invasive exotic plants. We examined whether the invasive shrub Lonicera maackii (Caprifoliaceae) affected fungi-mediated mortality of conspecific and native shrub seeds in a deciduous forest in eastern Missouri. Using a combination of L. maackii removal and fungicide treatments, we found no effect of L. maackii invasion on seed viability of the native Symphoricarpos orbiculatus (Caprifoliaceae) or Cornus drummondii (Cornaceae). In contrast, fungi were significant agents of L. maackii seed mortality in invaded habitats. Losses of L. maackii to soil fungi were also significant in invaded habitats where L. maackii had been removed, although the magnitude of the effect of fungi was lower, suggesting that changes in soil chemistry or microhabitat caused by L. maackii were responsible for affecting fungal seed pathogens. Our work suggests that apparent competition via soil pathogens is not an important factor contributing to impacts of L. maackii on native shrubs. Rather, we found that fungal seed pathogens have density-dependent effects on L. maackii seed survival. Therefore, while fungal pathogens may provide little biotic resistance to early invasion by L. maackii, our study illustrates that more work is needed to understand how changes in fungal pathogens during the course of an invasion contribute to the potential for restoration of invaded systems. More generally, our study suggests that increased rates of fungal pathogen attack may be realized by invasive plants, such as L. maackii, that change the chemical or physical environment of the habitats they invade.

  16. Effects of mining-derived metals on riffle-dwelling crayfish in southwestern Missouri and southeastern Kansas, USA

    Science.gov (United States)

    Allert, Ann L.; DiStefano, Robert J.; Schmitt, Christopher J.; Fairchild, James F.; Brumbaugh, William G.

    2012-01-01

    Riffle-dwelling crayfish populations were sampled at 16 sites in 4 tributaries of the Spring River located within the Tri-State Mining District in southwest Missouri. Crayfish density, physical habitat quality, and water quality were examined at each site to assess the ecological effects of mining-derived metals on crayfish. Metals (lead, zinc, and cadmium) were analyzed in samples of surface water, sediment, detritus, and whole crayfish. Sites were classified a posteriori into reference, mining, and downstream sites primarily based on metal concentrations in the materials analyzed. Three species of crayfish (Orconectes neglectus neglectus, O. macrus, and O. virilis) were collected during the study; however, only O. n. neglectus was collected at all sites. Mean crayfish densities were significantly lower at mining sites than at reference sites. Mean concentrations of metals were significantly correlated among the materials analyzed and were significantly greater at mining and downstream sites than at reference sites. Principal component analyses showed a separation of sites due to an inverse relationship among crayfish density, metals concentrations, and physical habitat quality variables. Sediment probable-effects quotients and surface-water toxic unit scores were significantly correlated; both indicated risk of toxicity to aquatic biota at several sites. Metals concentrations in whole crayfish at several sites exceeded concentrations known to be toxic to carnivorous wildlife. Mining-derived metals have the potential to impair ecosystem function through decreased organic matter processing and nutrient cycling in streams due to decreased crayfish densities.

  17. QUANTIFYING AND MODELING THE RISK OF DISTURBANCE TO ECOSYSTEMS CAUSED BY INVASIVE SPECIES

    Science.gov (United States)

    Invasive species are biological pollutants that threaten ecosystem health. Identifying the mechanisms of invasive and developing predictive models of invasion will be critical to developing risk management strategies for limiting the economic and environmental damage caused by i...

  18. Introduced cryptic species of parasites exhibit different invasion pathways.

    Science.gov (United States)

    Miura, Osamu; Torchin, Mark E; Kuris, Armand M; Hechinger, Ryan F; Chiba, Satoshi

    2006-12-26

    Sometimes infectious agents invade and become established in new geographic regions. Others may be introduced yet never become established because of the absence of suitable hosts in the new region. This phenomenon may be particularly true for the many parasites with complex life cycles, where various life stages require different host species. Homogenization of the world's biota through human-mediated invasions may reunite hosts and parasites, resulting in disease outbreaks in novel regions. Here we use molecular genetics to differentiate invasion pathways for two digenean trematode parasites and their exotic host, the Asian mud snail, Batillaria attramentaria. All of the snail haplotypes found in introduced populations in North America were identical to haplotypes common in the areas of Japan that provided oysters for cultivation in North America, supporting the hypothesis that the snails were introduced from Japan with seed oysters. Two cryptic trematode species were introduced to North American populations in high frequencies. We found a marked reduction of genetic variation in one of these species, suggesting it experienced a bottleneck or founder event comparable to that of the host snail. In contrast, no genetic variation was lost in the other parasite species. We hypothesize that this parasite was and is dispersed naturally by migratory shorebirds and was able to establish only after the host snail, B. attramentaria, was introduced to North America. Evaluation of the nature of invasion pathways and postinvasion consequences will aid mitigation of spreading diseases of humans, livestock, and wildlife in an increasingly globalized world.

  19. Optimal control of an invasive species with imperfect information about the level of infestation

    Science.gov (United States)

    Robert G. Haight; Stephen. Polasky

    2010-01-01

    The presence of invasive species is often not realized until well after the species becomes established. Discovering the location and extent of infestation before the invasive species causes widespread damage typically requires intensive monitoring efforts. In this paper, we analyze the problem of controlling an invasive species when there is imperfect information...

  20. Status of the white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858, in Spain : distribution and legislation

    Directory of Open Access Journals (Sweden)

    ALONSO F.

    2000-01-01

    Full Text Available The white-clawed crayfish, Austropotamobius pallipes, is the only native species of freshwater crayfish in Spain. This species sustained a first-magnitude inland fishery up to the end of 1970's, when the crayfish plague struck the Spanish waters. It is detected an overall loss of distribution area of populations inhabiting the medium and lower reaches of the main river catchments, especially in Southern and Central Spain. The number of surviving populations can be estimated in ca. 700. Remaining native crayfish populations currently inhabit marginal areas. The populations are very fragmented, occupy short stretches, and are frequently isolated from the main river system. The current distribution is the result of a sum of different factors, i.e. crayfish plague, habitat alterations, extreme climatic drought, etc. The incidence and relative importance of each one varied during the last 15 years, with crayfish plague being a predominant negative factor in the seventies and eighties, and climatic drought in the nineties. The current trend of disappearance is a sufficient reason to consider the native crayfish as at risk of extinction. However neither the national legislation nor most of the regional government legislations have listed this species as endangered. An analysis of the legislation dealing with freshwater crayfish in Spain shows : (a an uneven and generally low level of protection given to the native species and (b a very complex fishing and commercialization regulations for crayfish that show significant changes from one region to another. This complex legislation, complemented with a general lack of data on crayfish populations, low levels of management and public involvement, and different strategies in regional governments regarding restocking programs with exotic species, makes a confusing situation. In order to decrease the general tendency of regression of A. pallipes a conservation program for this species needs to be implemented

  1. Evolutionary responses of native plant species to invasive plants : a review

    OpenAIRE

    Oduor, Ayub M. O.

    2013-01-01

    Strong competition from invasive plant species often leads to declines in abundances and may,in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species, suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has invol...

  2. Using habitat suitability models to target invasive plant species surveys.

    Science.gov (United States)

    Crall, Alycia W; Jarnevich, Catherine S; Panke, Brendon; Young, Nick; Renz, Mark; Morisette, Jeffrey

    2013-01-01

    Managers need new tools for detecting the movement and spread of nonnative, invasive species. Habitat suitability models are a popular tool for mapping the potential distribution of current invaders, but the ability of these models to prioritize monitoring efforts has not been tested in the field. We tested the utility of an iterative sampling design (i.e., models based on field observations used to guide subsequent field data collection to improve the model), hypothesizing that model performance would increase when new data were gathered from targeted sampling using criteria based on the initial model results. We also tested the ability of habitat suitability models to predict the spread of invasive species, hypothesizing that models would accurately predict occurrences in the field, and that the use of targeted sampling would detect more species with less sampling effort than a nontargeted approach. We tested these hypotheses on two species at the state scale (Centaurea stoebe and Pastinaca sativa) in Wisconsin (USA), and one genus at the regional scale (Tamarix) in the western United States. These initial data were merged with environmental data at 30-m2 resolution for Wisconsin and 1-km2 resolution for the western United States to produce our first iteration models. We stratified these initial models to target field sampling and compared our models and success at detecting our species of interest to other surveys being conducted during the same field season (i.e., nontargeted sampling). Although more data did not always improve our models based on correct classification rate (CCR), sensitivity, specificity, kappa, or area under the curve (AUC), our models generated from targeted sampling data always performed better than models generated from nontargeted data. For Wisconsin species, the model described actual locations in the field fairly well (kappa = 0.51, 0.19, P guiding invasive species monitoring, and we support the use of an iterative sampling design for

  3. Optimising invasive fish management in the context of invasive species legislation in South Africa

    Directory of Open Access Journals (Sweden)

    Darragh J. Woodford

    2017-03-01

    Full Text Available Background: South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. Many of these species are now listed under the National Environmental Management: Biodiversity Act (NEM:BA Alien and Invasive Species (A&IS lists and regulations, though the practical options available to conservation agencies to effectively manage these fishes vary greatly among species and regions. Objectives & methods: We assessed the history and status of national legislation pertaining to invasive freshwater fishes, and the practical implications of the legislation for managing different species with contrasting distributions, impacts and utilisation value. Results: The smallmouth bass, despite being a potential conflict-generating species, is fairly straightforward to manage based on current legislation. Two species of trout, which remain absent from the NEM:BA A&IS lists because of ongoing consultation with stakeholders, continue to be managed in regions like the Western Cape province using existing provincial legislation. To maximise the limited capacity for management within conservation agencies, we proposed a decision-support tool that prioritises invasive fish populations that represent high environmental risk and low potential for conflict with stakeholders. Using three case studies, we demonstrated how the tool can be used to set management goals of ‘eradicate’, ‘manage against impacts and further spread’ and ‘continue to monitor population’ as the most pragmatic solutions given the state of an invasion, its socio-economic impact and the capacity of the responsible agency to act. Conclusion: By choosing a pragmatic management strategy, conservation agencies can maximise the effective deployment of limited resources, while minimising avoidable conflicts with stakeholders.

  4. An invasive foundation species enhances multifunctionality in a coastal ecosystem.

    Science.gov (United States)

    Ramus, Aaron P; Silliman, Brian R; Thomsen, Mads S; Long, Zachary T

    2017-08-08

    While invasive species often threaten biodiversity and human well-being, their potential to enhance functioning by offsetting the loss of native habitat has rarely been considered. We manipulated the abundance of the nonnative, habitat-forming seaweed Gracilaria vermiculophylla in large plots (25 m 2 ) on southeastern US intertidal landscapes to assess impacts on multiple ecosystem functions underlying coastal ecosystem services. We document that in the absence of native habitat formers, this invasion has an overall positive, density-dependent impact across a diverse set of ecosystem processes (e.g., abundance and richness of nursery taxa, flow attenuation). Manipulation of invader abundance revealed both thresholds and saturations in the provisioning of ecosystem functions. Taken together, these findings call into question the focus of traditional invasion research and management that assumes negative effects of nonnatives, and emphasize the need to consider context-dependence and integrative measurements when assessing the impact of an invader, including density dependence, multifunctionality, and the status of native habitat formers. This work supports discussion of the idea that where native foundation species have been lost, invasive habitat formers may be considered as sources of valuable ecosystem functions.

  5. Stream permanence influences crayfish occupancy and abundance in the Ozark Highlands, USA

    Science.gov (United States)

    Yarra, Allyson N.; Magoulick, Daniel D.

    2018-01-01

    Crayfish use of intermittent streams is especially important to understand in the face of global climate change. We examined the influence of stream permanence and local habitat on crayfish occupancy and species densities in the Ozark Highlands, USA. We sampled in June and July 2014 and 2015. We used a quantitative kick–seine method to sample crayfish presence and abundance at 20 stream sites with 32 surveys/site in the Upper White River drainage, and we measured associated local environmental variables each year. We modeled site occupancy and detection probabilities with the software PRESENCE, and we used multiple linear regressions to identify relationships between crayfish species densities and environmental variables. Occupancy of all crayfish species was related to stream permanence. Faxonius meeki was found exclusively in intermittent streams, whereas Faxonius neglectus and Faxonius luteushad higher occupancy and detection probability in permanent than in intermittent streams, and Faxonius williamsi was associated with intermittent streams. Estimates of detection probability ranged from 0.56 to 1, which is high relative to values found by other investigators. With the exception of F. williamsi, species densities were largely related to stream permanence rather than local habitat. Species densities did not differ by year, but total crayfish densities were significantly lower in 2015 than 2014. Increased precipitation and discharge in 2015 probably led to the lower crayfish densities observed during this year. Our study demonstrates that crayfish distribution and abundance is strongly influenced by stream permanence. Some species, including those of conservation concern (i.e., F. williamsi, F. meeki), appear dependent on intermittent streams, and conservation efforts should include consideration of intermittent streams as an important component of freshwater biodiversity.

  6. Do culverts impact the movements of the endangered white-clawed crayfish?

    Directory of Open Access Journals (Sweden)

    Louca V.

    2014-01-01

    Full Text Available Culverts can impact the migration and dispersal of aquatic animals and result in population fragmentation, increasing the risk of local extinction for endangered species such as the white-clawed crayfish Austropotamobius pallipes. This study used radio telemetry and passive integrated transponder (PIT telemetry to determine whether existing and experimental covered culverts affect the upstream and downstream movements of adult white-clawed crayfish. Daily crayfish movement rates did not differ significantly between an unlit 363-m long culvert and open stream channel sections. Crayfish moved into dark, covered sections volitionally. However, limited upstream movement occurred at sudden transitions of bed height or smooth-concrete box culvert sections with fast flow, suggesting partial barrier effects. In the 20-m long experimental in-stream culvert, also dark, but with natural stream bed, 70% of radio-tagged crayfish released downstream entered the culvert, as did 60% of those released upstream. Overall 35% passed through, with similar numbers in each direction. We conclude that dark culverts up to several hundred metres do not inhibit dispersal of white-clawed crayfish, provided stream slope, bed type and water velocity are amenable for movement and refuge. Care is required to ensure that culverts are bioengineered to ensure that average water velocity is sufficiently low and local hydraulic variation high, the bed and/or sidewalls contain refuge structures, and there are no cross-channel steps in bed level. Smooth-bedded box culverts are unlikely to be suitable for white-clawed crayfish.

  7. Floristic characteristics of alien invasive seed plant species in China.

    Science.gov (United States)

    Wang, Congyan; Liu, Jun; Xiao, Hongguang; Zhou, Jiawei; DU, Daolin

    2016-01-01

    This study aims to determine the floristic characteristics of alien invasive seed plant species (AISPS) in China. There are a total of five hundred and thirteen AISPS, belonging to seventy families and two hundred and eighty-three genera. Seventy families were classified into nine areal types at the family level, and "Cosmopolitan" and "Pantropic" are the two main types. Two hundred and eighty-three genera were classified into twelve areal types at the genus level, and "Pantropic", "Trop. Asia & Amer. disjuncted", and "Cosmopolitan" are the three main types. These results reveal a certain degree of diversity among AISPS in China. The floristic characteristics at the family level exhibit strong pantropic characteristics. Two possible reasons for this are as follows. Firstly, southeastern China is heavily invaded by alien invasive plant species and this region has a mild climate. Secondly, southeastern China is more disturbed by human activities than other regions in China. The floristic characteristics at the genus level display strong pantropic but with abundant temperate characteristics. This may be due to that China across five climatic zones and the ecosystems in which the most alien invasive plant species occur have the same or similar climate with their natural habitat.

  8. Invasive vascular plant species of limnocrenic karst springs in Poland

    Science.gov (United States)

    Spałek, Krzysztof

    2015-04-01

    Natural water reservoirs are very valuable floristic sites in Poland. Among them, the most important for preservation of biodiversity of flora are limnocrenic karst springs. The long-term process of human pressure on habitats of this type caused disturbance of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of last two hundred years, led to systematic disappearance of localities of many plant species connected with rare habitats and also to appear numerous invasive plant species. They are: Acorus calamus, Echinocystis lobata, Elodea canadensis, Erechtites hieraciifolia, Impatiens glandulifera, Solidago canadensis, S. gigantea and S. graminifolia. Fielworks were conducted in 2010-2014.

  9. Responses of the soil fungal communities to the co-invasion of two invasive species with different cover classes.

    Science.gov (United States)

    Wang, C; Zhou, J; Liu, J; Jiang, K; Xiao, H; Du, D

    2018-01-01

    Soil fungal communities play an important role in the successful invasion of non-native species. It is common for two or more invasive plant species to co-occur in invaded ecosystems. This study aimed to determine the effects of co-invasion of two invasive species (Erigeron annuus and Solidago canadensis) with different cover classes on soil fungal communities using high-throughput sequencing. Invasion of E. annuus and/or S. canadensis had positive effects on the sequence number, operational taxonomic unit (OTU) richness, Shannon diversity, abundance-based cover estimator (ACE index) and Chao1 index of soil fungal communities, but negative effects on the Simpson index. Thus, invasion of E. annuus and/or S. canadensis could increase diversity and richness of soil fungal communities but decrease dominance of some members of these communities, in part to facilitate plant further invasion, because high soil microbial diversity could increase soil functions and plant nutrient acquisition. Some soil fungal species grow well, whereas others tend to extinction after non-native plant invasion with increasing invasion degree and presumably time. The sequence number, OTU richness, Shannon diversity, ACE index and Chao1 index of soil fungal communities were higher under co-invasion of E. annuus and S. canadensis than under independent invasion of either individual species. The co-invasion of the two invasive species had a positive synergistic effect on diversity and abundance of soil fungal communities, partly to build a soil microenvironment to enhance competitiveness of the invaders. The changed diversity and community under co-invasion could modify resource availability and niche differentiation within the soil fungal communities, mediated by differences in leaf litter quality and quantity, which can support different fungal/microbial species in the soil. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  10. Effects of Climate Change on Aquatic Invasive Species and Implications for Management and Research (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Effects of Climate Change on Aquatic Invasive Species and Implications for Management and Research . This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines sta...

  11. Economics of controlling invasive species: the case of Californian thistle in New Zealand

    NARCIS (Netherlands)

    Chalak, S.M.

    2009-01-01

    Keywords
    Invasive species, Economics, Californian thistle, New Zealand, Stochastic, Dynamic programming, Biological control, Extinction risk, Herbivory, Dispersal, Competition
    Invasive species are one of the most significant threats to biodiversity and agricultural production systems

  12. Floristic analysis of perennial species on flowerbeds in Belgrade with special attention on invasiveness of the recorded species

    Directory of Open Access Journals (Sweden)

    Popović Marija

    2012-01-01

    Full Text Available Urban areas are among the most important centres of invasive plant species distribution due to their richness in alien species. Because of that, a detailed floristic analysis of perennial flowerbeds was conducted in the central parks of Belgrade. A total of 53 perennial species were found, of which 55% were the alien species planted on 75% of the research area. Among them, two species (Aster novi belgii and Solidago canadensis are invasive and six species are potentially invasive in Serbia. These are planted on 5% and 20% of the flowerbeds, respectively. We can conclude that both the experts and institutions should be informed about the invasive species and potential damages. In the meantime, planting of native decorative species should be encouraged, since they will not pose a threat to natural habitats. Also, detailed research should be conducted in order to eradicate invasive and potentially invasive species from the surfaces around the research area.

  13. Evaluating Hypotheses of Plant Species Invasions on Mediterranean Islands: Inverse Patterns between Alien and Endemic Species

    Directory of Open Access Journals (Sweden)

    Alexander Bjarnason

    2017-08-01

    Full Text Available Invasive alien species cause major changes to ecosystem functioning and patterns of biodiversity, and the main factors involved in invasion success remain contested. Using the Mediterranean island of Crete, Greece as a case study, we suggest a framework for analyzing spatial data of alien species distributions, based on environmental predictors, aiming to gain an understanding of their spatial patterns and spread. Mediterranean islands are under strong ecological pressure from invading species due to their restricted size and increased human impact. Four hypotheses of invasibility, the “propagule pressure hypothesis” (H1, “biotic resistance hypothesis vs. acceptance hypothesis” (H2, “disturbance-mediated hypothesis” (H3, and “environmental heterogeneity hypothesis” (H4 were tested. Using data from alien, native, and endemic vascular plant species, the propagule pressure, biotic resistance vs. acceptance, disturbance-mediated, and environmental heterogeneity hypotheses were tested with Generalized Additive Modeling (GAM of 39 models. Based on model selection, the optimal model includes the positive covariates of native species richness, the negative covariates of endemic species richness, and land area. Variance partitioning between the four hypotheses indicated that the biotic resistance vs. acceptance hypothesis explained the vast majority of the total variance. These results show that areas of high species richness have greater invasibility and support the acceptance hypothesis and “rich-get-richer” distribution of alien species. The negative correlation between alien and endemic species appears to be predominantly driven by altitude, with fewer alien and more endemic species at greater altitudes, and habitat richness. The negative relationship between alien and endemic species richness provides potential for understanding patterns of endemic and alien species on islands, contributing to more effective conservation

  14. Characterization of Population Genetic Structure of red swamp crayfish, Procambarus clarkii, in China.

    Science.gov (United States)

    Yi, Shaokui; Li, Yanhe; Shi, Linlin; Zhang, Long; Li, Qingbin; Chen, Jing

    2018-04-03

    The red swamp crayfish (Procambarus clarkii) is one of the most economically important farmed aquatic species in China. However, it is also a famous invasive species in the world. This invasive species was dispersed most via human activities including intentional or unintentional carry in China. Thus, P. clarkii naturally distributed in China provides us a desirable mode to investigate the genetic structure of an invasive species dispersed mainly by human-mediated factors. To reveal the impact of human-mediated dispersal on genetic structure of P. clarkii in China, a total of 22,043 genome-wide SNPs were obtained from approximately 7.4 billion raw reads using 2b-RAD technique in this study. An evident pattern of population genetic structure and the asymmetrical migrational rates between different regions were observed with 22 populations based on these SNPs. This study provide a better understanding of the population genetic structure and demographic history of P. clarkii populations in China, inferring that anthropogenic factors (aquaculture or by accident) and ecological factors (e.g., complicated topography and climatic environment), as well as its special biological traits could account for the current population structure pattern and dispersal history of P. clarkii.

  15. KEYNOTE PRESENTATION AND ROUNDTABLE SESSION 4. CRAYFISH PATHOLOGY IN EUROPE:PAST, PRESENT AND A PROGRAMME FOR THE FUTURE

    Directory of Open Access Journals (Sweden)

    EDGERTON B. F.

    2004-01-01

    Full Text Available The devastating affects of disease on European freshwater crayfish are well known as epizootics in wild populations have occurred throughout much of Europe since the mid XVIIIe s. After protracted and rigorous debate, the cause of the disease named crayfish plague was proved to be the fungus Aphanomyces astaci in 1934. In the last 70 years, much of the research conducted in the field of crayfish pathology has concentrated on fungi, especially improving diagnostic techniques for A. astaci. Similarly, diagnostic responses to epizootics in European crayfish have concentrated almost entirely on fungal isolation and/or identification. On the other hand, viruses have proved to be the most important pathogens in the growing global crustacean aquaculture and fishery industries. Rickettsia-like organisms (RLO are also important. Critically, diagnostic techniques necessary to detect the full range of potential pathogens of crayfish are rarely utilized in the field of crayfish pathology in Europe. Histopathological analysis, required for the diagnosis of infections by viruses and RLOs, is absent from most European studies. Epizootics unrelated to A. astaci in European crayfish and epizootics in introduced American crayfish species highlight the inadequate current state of knowledge in the field. Presently, the field is ill-equipped to determine the cause(s of these epizootics. Moreover, crayfish conservation strategies may be undermined and even detrimental to the longterm goals; eg., stocking programs may spread undetected pathogens. Therefore, critical limitations in the field of crayfish pathology have major repercussions in management of freshwater crayfish. Guiding principles and a concept for a trans-European Community research and education program were developed to address this serious issue and are presented herein.

  16. When does invasive species removal lead to ecological recovery? Implications for management success

    Science.gov (United States)

    Kirsten M. Prior; Damian C. Adams; Kier D. Klepzig; Jiri Hulcr

    2018-01-01

    The primary goal of invasive species management is to eliminate or reduce populations of invasive species. Although management efforts are often motivated by broader goals such as to reduce the negative impacts of invasive species on ecosystems and society, there has been little assessment of the consistency between population-based (e.g., removing invaders) and...

  17. The Dispersal and Persistence of Invasive Marine Species

    Science.gov (United States)

    Glick, E. R.; Pringle, J.

    2007-12-01

    The spread of invasive marine species is a continuing problem throughout the world, though not entirely understood. Why do some species invade more easily than the rest? How are the range limits of these species set? Recent research (Byers & Pringle 2006, Pringle & Wares 2007) has produced retention criteria that determine whether a coastal species with a benthic adult stage and planktonic larvae can be retained within its range and invade in the direction opposite that of the mean current experienced by the larvae (i.e. upstream). These results however, are only accurate for Gaussian dispersal kernels. For kernels whose kurtosis differs from a Gaussian's, the retention criteria becomes increasingly inaccurate as the mean current increases. Using recent results of Lutscher (2006), we find an improved retention criterion which is much more accurate for non- Gaussian dispersal kernels. The importance of considering non-Gaussian kernels is illustrated for a number of commonly used dispersal kernels, and the relevance of these calculations is illustrated by considering the northward limit of invasion of Hemigrapsus sanguineus, an important invader in the Gulf of Maine.

  18. Applying remote sensing to invasive species science—A tamarisk example

    Science.gov (United States)

    Morisette, Jeffrey T.

    2011-01-01

    The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. This fact sheet considers the invasive plant species tamarisk (Tamarix spp), addressing three fundamental questions: *Where is it now? *What are the potential or realized ecological impacts of invasion? *Where can it survive and thrive if introduced? It provides peer-review examples of how the U.S. Geological Survey, working with other federal agencies and university partners, are applying remote-sensing technologies to address these key questions.

  19. Priority setting for invasive species management: risk assessment of Ponto-Caspian invasive species into Great Britain.

    Science.gov (United States)

    Gallardo, Belinda; Aldridge, David C

    2013-03-01

    Invasive species drive important ecological and economic losses across wide geographies, with some regions supporting especially large numbers of nonnative species and consequently suffering relatively high impacts. For this reason, integrated risk assessments able to screen a suite of multiple invaders over large geographic areas are needed for prioritizing the allocation of limited resources. A total of 16 Ponto-Caspian aquatic species (10 gammarids, one isopod, two mysids, and three fishes) have been short-listed as recent or potential future invaders of British waters, whose introduction and spread is of high concern. In this study, we use multiple modeling techniques to assess their risk of establishment and spread into Great Britain. Climate suitability maps for these 16 species differed depending on the eastern and western distribution of species in continental Europe, which was related to their respective migration corridor: southern (Danube-Rhine rivers), and northern (Don and Volga rivers and Baltic lakes). Species whose suitability was high across large parts of Great Britain included four gammarids (Cheliorophium robustum, Dikerogammarus bispinosus, D. villosus, and Echinogammarus trichiatus) and a mysid (Hemimysis anomala). A climatic "heat map" combining the results of all 16 species together pointed to the southeast of England as the area most vulnerable to multiple invasions, particularly the Thames, Anglian, Severn, and Humber river basin districts. Regression models further suggested that alkalinity concentration > 120 mg/L in southeast England may favor the establishment of Ponto-Caspian invaders. The production of integrated risk maps for future invaders provides a means for the scientifically informed prioritization of resources toward particular species and geographic regions. Such tools have great utility in helping environmental managers focus efforts on the most effective prevention, management, and monitoring programs.

  20. A Framework for Spatial Risk Assessments: Potential Impacts of Nonindigenous Invasive Species on Native Species

    Directory of Open Access Journals (Sweden)

    Craig R. Allen

    2006-06-01

    Full Text Available Many populations of wild animals and plants are declining and face increasing threats from habitat fragmentation and loss as well as exposure to stressors ranging from toxicants to diseases to invasive nonindigenous species. We describe and demonstrate a spatially explicit ecological risk assessment that allows for the incorporation of a broad array of information that may influence the distribution of an invasive species, toxicants, or other stressors, and the incorporation of landscape variables that may influence the spread of a species or substances. The first step in our analyses is to develop species models and quantify spatial overlap between stressor and target organisms. Risk is assessed as the product of spatial overlap and a hazard index based on target species vulnerabilities to the stressor of interest. We illustrate our methods with an example in which the stressor is the ecologically destructive nonindigenous ant, Solenopsis invicta, and the targets are two declining vertebrate species in the state of South Carolina, USA. A risk approach that focuses on landscapes and that is explicitly spatial is of particular relevance as remaining undeveloped lands become increasingly uncommon and isolated and more important in the management and recovery of species and ecological systems. Effective ecosystem management includes the control of multiple stressors, including invasive species with large impacts, understanding where those impacts may be the most severe, and implementing management strategies to reduce impacts.

  1. Invasive plant species in the West Indies: geographical, ecological, and floristic insights.

    Science.gov (United States)

    Rojas-Sandoval, Julissa; Tremblay, Raymond L; Acevedo-Rodríguez, Pedro; Díaz-Soltero, Hilda

    2017-07-01

    The level of invasion (number or proportion of invasive species) in a given area depends on features of the invaded community, propagule pressure, and climate. In this study, we assess the invasive flora of nine islands in the West Indies to identify invasion patterns and evaluate whether invasive species diversity is related to geographical, ecological, and socioeconomic factors. We compiled a database of invasive plant species including information on their taxonomy, origin, pathways of introduction, habitats, and life history. This database was used to evaluate the similarity of invasive floras between islands and to identify invasion patterns at regional (West Indies) and local (island) scales. We found a total of 516 alien plant species that are invasive on at least one of the nine islands studied, with between 24 to 306 invasive species per island. The invasive flora on these islands includes a wide range of taxonomic groups, life forms, and habitats. We detected low similarity in invasive species diversity between islands, with most invasive species (>60%) occurring on a single island and 6% occurring on at least five islands. To assess the importance of different models in predicting patterns of invasive species diversity among islands, we used generalized linear models. Our analyses revealed that invasive species diversity was well predicted by a combination of island area and economic development (gross domestic product per capita and kilometers of paved roadways). Our results provide strong evidence for the roles of geographical, ecological, and socioeconomic factors in determining the distribution and spread of invasive species on these islands. Anthropogenic disturbance and economic development seem to be the major drivers facilitating the spread and predominance of invasive species over native species.

  2. Species coexistence and the superior ability of an invasive species to exploit a facilitation cascade habitat

    Directory of Open Access Journals (Sweden)

    Andrew H. Altieri

    2017-02-01

    Full Text Available Facilitation cascades generated by co-occurring foundation species can enhance the abundance and diversity of associated organisms. However, it remains poorly understood how differences among native and invasive species in their ability to exploit these positive interactions contribute to emergent patterns of community structure and biotic acceptance. On intertidal shorelines in New England, we examined the patterns of coexistence between the native mud crabs and the invasive Asian shore crab in and out of a facilitation cascade habitat generated by mid intertidal cordgrass and ribbed mussels. These crab species co-occurred in low intertidal cobbles adjacent to the cordgrass–mussel beds, despite experimental findings that the dominant mud crabs can kill and displace Asian shore crabs and thereby limit their successful recruitment to their shared habitat. A difference between the native and invasive species in their utilization of the facilitation cascade likely contributes to this pattern. Only the Asian shore crabs inhabit the cordgrass–mussel beds, despite experimental evidence that both species can similarly benefit from stress amelioration in the beds. Moreover, only Asian shore crabs settle in the beds, which function as a nursery habitat free of lethal mud crabs, and where their recruitment rates are particularly high (nearly an order of magnitude higher than outside beds. Persistence of invasive adult Asian shore crabs among the dominant native mud crabs in the low cobble zone is likely enhanced by a spillover effect of the facilitation cascade in which recruitment-limited Asian shore crabs settle in the mid intertidal cordgrass–mussel beds and subsidize their vulnerable populations in the adjacent low cobble zone. This would explain why the abundances of Asian shore crabs in cobbles are doubled when adjacent to facilitation cascade habitats. The propensity for this exotic species to utilize habitats created by facilitation cascades

  3. A SURVEY OF THE WHITE-CLAWED CRAYFISH,AUSTROPOTAMOBIUS PALLIPES (LEREBOULLET, AND OF WATERQUALITY IN TWO CATCHMENTS OF EASTERN IRELAND.

    Directory of Open Access Journals (Sweden)

    DEMERS A.

    2002-07-01

    Full Text Available The white-clawed crayfish, Austropotamobius pallipes (Lereboullet, is the only crayfish species found in Ireland. Because of the prohibition on importation of exotic species of crayfish onto the island and of its relatively clean rivers up to now, Ireland has kept an abundant population of crayfish. A survey was conducted in the catchments of the Liffey and Boyne rivers, in eastern Ireland to assess water quality and to sample crayfish populations. The aim of the study was to evaluate the water quality requirements of the white-clawed crayfish in Ireland. Baited traps and nets were used to sample crayfish while water quality was measured with biological indices calculated from samples of macroinvertebrates. Distribution of this crayfish species is patchy in the Liffey catchment and seems to be related to factors such as soil types and water quality. They were not found in the downstream part of the river Liffey possibly due to poor water quality. In the Boyne catchment, no crayfish were found in most of the catchment. They were only present in the Kells Blackwater subcatchment. This may be due to an earlier outbreak of the fungal plague caused by Aphanomyces astaci. The disease was discovered in lakes at the top of some of the tributaries of the Boyne in 1987 and it probably spread from there through the whole catchment.

  4. REVIEW OF THE NATIONAL RESTOCKING PROGRAMME “ACTIVE PROTECTION OF NATIVE CRAYFISH IN POLAND” 1999-2001

    Directory of Open Access Journals (Sweden)

    ŠMIETANA P.

    2004-01-01

    Full Text Available After the first spread of crayfish plague (aphanomycosis at the end of the nineteenth century, the formerly abundant populations of native crayfish in Poland declined drastically. Analysis of historical data on the occurrence and distribution of crayfish in Poland led to the conclusion that without human intervention the native crayfish species would be at high risk of being made extinct. The largest programme concerning crayfish monitoring and restocking in Poland was “Active protection of native crayfish in Poland” conducted by the Inland Fisheries Institute, the Department of Ecology, University of Szczecin, the Department of Zoology, Warsaw Agricultural University and the University of Warmia and Mazury that was funded by the EkoFundusz Foundation and Inland Fisheries Institute in 1999-2001. One of the main objectives and results of this programme was the determination of indigenous crayfish distribution in Poland (mainly Astacus astacus and Astacus leptodactylus and the restocking of suitable habitats with indigenous crayfish. The densest populations (> 2 500 adult individuals per hectare were used as a source of restocking material. Restocking was performed in 54 water bodies using a total of 45 200 individuals of A. astacus and 9 800 of A. leptodactylus. Between 2001-2002, the success of the restocking programme was monitored. According to the results obtained so far, the restocking exercise has been successful in at least 60.8% of the cases.

  5. Invasive species in phytocenosis of Sterlitamak town (Republic of Bashkortostan, Russia)

    Science.gov (United States)

    Golovanov, Ya M.; Abramova, L. M.; Petrov, S. S.

    2018-01-01

    There were 69 invasive and potentially invasive species in the flora of Sterlitamak in the Bashkortostan Republic (Russia). Eight are in the most dangerous types of invasive species. The greatest danger is represented by: Acer negundo, Ambrosia trifida, Elodea canadensis and Xanthium albinum. Within the boundaries of Sterlitamak, 21 syntaxa (13 associations and 8 derivated communities) are invasive species. This phytocenosis in an urban environment can be prime targets for plant quarantine actions.

  6. EXPERIMENTAL EVIDENCE FOR HOMING IN THE RED SWAMP CRAYFISH, PROCAMBARUS CLARKII

    Directory of Open Access Journals (Sweden)

    BARBARESI S.

    2006-01-01

    Full Text Available The red swamp crayfish, Procambarus clarkii, is an efficient burrower, but its burrow fidelity has been recently questioned. In this study, we aimed at investigating whether individuals of this species are capable to learn the position of a goal (a wet burrow hidden to their sight in experimental tanks and to make more efficient with time their oriented movement towards it. We also analyzed crayfish behavior after having closed one of the two accesses to the goal. Indeed, in successive trials we recorded the crayfish tendency to reduce the distance covered to reach the goal and the time taken, except when they were already familiar to the experimental setting. Memory of the spatial configuration lasted for 16 hours at least and crayfish learned and maintained individual trajectories. The interruption of their usual path always caused a drastic increase of distance and time that however decreased in the successive trials. This study provided also some information of the sensory channels used by P. clarkii to orient. This crayfish, which can be active also during daytime, seemed to adopt a combination of tactile and visual information, together with the possible use of cues (i.e. humidity cues emitted by the goal. Future studies should clarify the paradox of a crayfish species whose individuals, although being physiologically capable to home, seem not to return to the previously occupied burrows at the end of their foraging excursions, notwithstanding the time and energy expended to excavate them.

  7. No universal scale-dependent impacts of invasive species on native plant species richness.

    Science.gov (United States)

    Stohlgren, Thomas J; Rejmánek, Marcel

    2014-01-01

    A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species-area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 (Science 339, 316-318. (doi:10.1126/science.1226817)), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness-log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal.

  8. Species invasion shifts the importance of predator dependence.

    Science.gov (United States)

    Griffen, Blaine D; Delaney, David G

    2007-12-01

    The strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. Here we demonstrate how the replacement of a previously established invader, the predatory crab Carcinus maenas, by the recently invading predatory crab Hemigrapsus sanguineus shifts predation from a species that experiences strong predator interference (strong predator dependence) to one that experiences weak predator interference (weak predator dependence). We demonstrate using field experiments that differences in the strength of predator dependence persist for these species both when they forage on a single focal prey species only (the mussel Mytilus edulis) and when they forage more broadly across the entire prey community. This shift in predator dependence with species replacement may be altering the biomass across trophic levels, consistent with theoretical predictions, as we show that H. sanguineus populations are much larger than C. maenas populations throughout their invaded ranges. Our study highlights that predator dependence may differ among predator species and demonstrates that different predatory impacts of two conspicuous invasive predators may be explained at least in part by different strengths of predator dependence.

  9. Founding population size of an aquatic invasive species

    Science.gov (United States)

    Kalinowski, Steven T.; Muhlfeld, Clint C.; Guy, Christopher S.; Benjamin Cox,

    2010-01-01

    Non-native species of fish threaten native fishes throughout North America, and in the Rocky Mountains, introduced populations of lake trout threaten native populations of bull trout. Effective management of lake trout and other exotic species require understanding the dynamics of invasion in order to either suppress non-native populations or to prevent their spread. In this study, we used microsatellite genetic data to estimate the number of lake trout that invaded a population of bull trout in Swan Lake, MT. Examination of genetic diversity and allele frequencies within the Swan Lake populations showed that most of the genes in the lake trout population are descended from two founders. This emphasizes the importance of preventing even a few lake trout from colonizing new territory.

  10. When can efforts to control nuisance and invasive species backfire?

    Science.gov (United States)

    Zipkin, Elise F; Kraft, Clifford E; Cooch, Evan G; Sullivan, Patrick J

    2009-09-01

    Population control through harvest has the potential to reduce the abundance of nuisance and invasive species. However, demographic structure and density-dependent processes can confound removal efforts and lead to undesirable consequences, such as overcompensation (an increase in abundance in response to harvest) and instability (population cycling or chaos). Recent empirical studies have demonstrated the potential for increased mortality (such as that caused by harvest) to lead to overcompensation and instability in plant, insect, and fish populations. We developed a general population model with juvenile and adult stages to help determine the conditions under which control harvest efforts can produce unintended outcomes. Analytical and simulation analyses of the model demonstrated that the potential for overcompensation as a result of harvest was significant for species with high fecundity, even when annual stage-specific survivorship values were fairly low. Population instability as a result of harvest occurred less frequently and was only possible with harvest strategies that targeted adults when both fecundity and adult survivorship were high. We considered these results in conjunction with current literature on nuisance and invasive species to propose general guidelines for assessing the risks associated with control harvest based on life history characteristics of target populations. Our results suggest that species with high per capita fecundity (over discrete breeding periods), short juvenile stages, and fairly constant survivorship rates are most likely to respond undesirably to harvest. It is difficult to determine the extent to which overcompensation and instability could occur during real-world removal efforts, and more empirical removal studies should be undertaken to evaluate population-level responses to control harvests. Nevertheless, our results identify key issues that have been seldom acknowledged and are potentially generic across taxa.

  11. Seed Removal Increased by Scramble Competition with an Invasive Species.

    Science.gov (United States)

    Minor, Rebecca L; Koprowski, John L

    2015-01-01

    Competition for seeds has a major influence on the evolution of granivores and the plants on which they rely. The complexity of interactions and coevolutionary relationships vary across forest types. The introduction of non-native granivores has considerable potential to alter seed dispersal dynamics. Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As biological invasions continue to rise, it is important to understand mechanisms to build up strategies to mitigate the threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti) on rates of seed removal within the range of critically endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis), which consumes similar foods. In the presence of invasive Abert's squirrels, the time cones were removed was faster than when the invasive was excluded, accounting for a median removal time of cones available to red and Abert's squirrels that is 32.8% less than that of cones available only to the rare native red squirrels. Moreover, in the presence of Abert's squirrels, removal rates are higher at great distance from a territorial red squirrel larderhoard and in more open portions of the forest, which suggests differential patterns of seed dispersal. The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Furthermore, the magnitude and differential spatial patterns of seed removal suggest that non-native granivores may have impacts on forest regeneration and structure.

  12. Seed Removal Increased by Scramble Competition with an Invasive Species.

    Directory of Open Access Journals (Sweden)

    Rebecca L Minor

    Full Text Available Competition for seeds has a major influence on the evolution of granivores and the plants on which they rely. The complexity of interactions and coevolutionary relationships vary across forest types. The introduction of non-native granivores has considerable potential to alter seed dispersal dynamics. Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As biological invasions continue to rise, it is important to understand mechanisms to build up strategies to mitigate the threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti on rates of seed removal within the range of critically endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis, which consumes similar foods. In the presence of invasive Abert's squirrels, the time cones were removed was faster than when the invasive was excluded, accounting for a median removal time of cones available to red and Abert's squirrels that is 32.8% less than that of cones available only to the rare native red squirrels. Moreover, in the presence of Abert's squirrels, removal rates are higher at great distance from a territorial red squirrel larderhoard and in more open portions of the forest, which suggests differential patterns of seed dispersal. The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Furthermore, the magnitude and differential spatial patterns of seed removal suggest that non-native granivores may have impacts on forest regeneration and structure.

  13. Ecological and economic determinants of invasive tree species on Alabama forestland

    Science.gov (United States)

    Anwar Hussain; Changyou Sun; Xiaoping Zhou; Ian A. Munn

    2008-01-01

    The spread of invasive tree species has caused increasing harm to the environment. This study was motivated by the considerations that earlier studies generally ignored the role of economic factors related to the occurrence and abundance of invasive species, and empirical analyses of invasive trees on forestland have been inadequate. We assessed the impact of...

  14. Fire and invasive exotic plant species in eastern oak communities: an assessment of current knowledge

    Science.gov (United States)

    Cynthia D. Huebner

    2006-01-01

    Successful regeneration of oak-dominated communities in the Eastern United States historically requires disturbance such as fire, making them vulnerable to invasion by exotic plants. Little is currently known about the effects of fire on invasive plant species and the effects of invasive plant species on fire regimes of this region. Seventeen common eastern invaders...

  15. Risk analysis and bioeconomics of invasive species to inform policy and management

    Science.gov (United States)

    David M. Lodge; Paul W. Simonin; Stanley W. Burgiel; Reuben P. Keller; Jonathan M. Bossenbroek; Christopher L. Jerde; Andrew M. Kramer; Edward S. Rutherford; Matthew A. Barnes; Marion E. Wittmann; W. Lindsay Chadderton; Jenny L. Apriesnig; Dmitry Beletsky; Roger M. Cooke; John M. Drake; Scott P. Egan; David C. Finnoff; Crysta A. Gantz; Erin K. Grey; Michael H. Hoff; Jennifer G. Howeth; Richard A. Jensen; Eric R. Larson; Nicholas E. Mandrak; Doran M. Mason; Felix A. Martinez; Tammy J. Newcomb; John D. Rothlisberger; Andrew J. Tucker; Travis W. Warziniack; Hongyan. Zhang

    2016-01-01

    Risk analysis of species invasions links biology and economics, is increasingly mandated by international and national policies, and enables improved management of invasive species. Biological invasions proceed through a series of transition probabilities (i.e., introduction, establishment, spread, and impact), and each of these presents opportunities for...

  16. Modulation of biodiversity-invasion relationships by resource availability : commensal species defend invaders in a changing world

    NARCIS (Netherlands)

    Yang, T.

    2017-01-01

    Biological invasion brings disturbance to localenvironment, such as reducing available niches or altering species interactions. In order to reduce the undesired consequences brought by invasion, the determining factors suppressing invasion become important. The success of invasion depends on

  17. Mechanisms controlling the distribution of two invasive Bromus species

    Directory of Open Access Journals (Sweden)

    Olga Bykova

    2014-03-01

    Full Text Available In order to predict future range shifts for invasive species it is important to explore their ability to acclimate to the new environment and understand physiological and reproductive constraints controlling their distribution. My dissertation studied mechanisms by which temperature may affect the distribution of two aggressive plant invaders in North America, Bromus tectorum and Bromus rubens. I first evaluated winter freezing tolerance of Bromus species and demonstrated that the mechanism explaining their distinct northern range limits is different acquisition time of freezing tolerance. While B. rubens has a slower rate of freezing acclimation that leads to intolerance of sudden, late-autumn drops in temperature below -12°C, B. tectorum rapidly hardens and so is not impacted by the sudden onset of severe late-autumn cold. In addition, the analysis of male reproductive development and seed production showed that neither species produces seed at or above 36°C, due to complete pollen sterility, which might trigger climate-mediated range contractions at B. tectorum and B. rubens southern margins. Finally, a detailed gas-exchange analysis combined with biochemical modelling demonstrated that both species acclimate to a broad range of temperatures and photosynthetic response to temperature does not explain their current range separation.

  18. Invasive Species Biology, Control, and Research. Part 1: Kudzu (Pueraria montana)

    National Research Council Canada - National Science Library

    Guertin, Patrick J; Denight, Michael L; Gebhart, Dick L; Nelson, Linda

    2008-01-01

    ..., and damage to equipment and structures. Of the 11 plant species (or groups) identified by installations as uncontrolled vegetation, six were invasive plants, of which the two invasive plants most commonly identified were Kudzu (Pueraria montana...

  19. Invasive Species Biology, Control, and Research. Part 2. Multiflora Rose (Rosa multiflora)

    National Research Council Canada - National Science Library

    Denight, Michael L; Guertin, Patrick J; Gebhart, Dick L; Nelson, Linda

    2008-01-01

    ..., and damage to equipment and structures. Of the 11 plant species (or groups) identified by installations as "uncontrolled vegetation," six were invasive plants, of which the two invasive plants most commonly identified were Kudzu (Pueraria montana...

  20. Plant functional traits of dominant native and invasive species in mediterranean-climate ecosystems.

    Science.gov (United States)

    Funk, Jennifer L; Standish, Rachel J; Stock, William D; Valladares, Fernando

    2016-01-01

    The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean-climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean-climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation. .

  1. Annotated list of marine alien species in the Mediterranean with records of the worst invasive species

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2005-12-01

    Full Text Available This collaborative effort by many specialists across the Mediterranean presents an updated annotated list of alien marine species in the Mediterranean Sea. Alien species have been grouped into six broad categories namely established, casual, questionable, cryptogenic, excluded and invasive, and presented in lists of major ecofunctional/taxonomic groups. The establishment success within each group is provided while the questionable and excluded records are commented in brief. A total of 963 alien species have been reported from the Mediterranean until December 2005, 218 of which have been classified as excluded (23% leaving 745 of the recorded species as valid aliens. Of these 385 (52% are already well established, 262 (35% are casual records, while 98 species (13% remain “questionable” records. The species cited in this work belong mostly to zoobenthos and in particular to Mollusca and Crustacea, while Fish and Phytobenthos are the next two groups which prevail among alien biota in the Mediterranean. The available information depends greatly on the taxonomic group examined. Thus, besides the three groups explicitly addressed in the CIESM atlas series (Fish, Decapoda/Crustacea and Mollusca, which are however updated in the present work, Polychaeta, Phytobenthos, Phytoplankton and Zooplankton are also addressed in this study. Among other zoobenthic taxa sufficiently covered in this study are Echinodermata, Sipuncula, Bryozoa and Ascidiacea. On the contrary, taxa such as Foraminifera, Amphipoda and Isopoda, that are not well studied in the Mediterranean, are insufficiently covered. A gap of knowledge is also noticed in Parasites, which, although ubiquitous and pervasive in marine systems, have been relatively unexplored as to their role in marine invasions. Conclusively the lack of funding purely systematic studies in the region has led to underestimation of the number of aliens in the Mediterranean. Emphasis is put on those species that are

  2. Assessing the importance of food for improving noble crayfish culture conditions

    Directory of Open Access Journals (Sweden)

    Rusch J.C.

    2015-01-01

    Full Text Available Captive breeding and crayfish culture are considered important measures in species protection activities. Thus, knowledge on optimal feeding of crayfish in captivity is needed in order to secure minimal mortality and prevent detrimental effects to health. To optimize conditions of crayfish prior to subsequent stocking, feeding trials were conducted with the aim of investigating the connection between food intake, food preference and temperature under near natural conditions. During a five-month period, noble crayfish were fed on fish, carrots, algae and chironomid-larvae according to a pre-defined rotation system, whereby the ambient water temperature ranged from 5 °C to 13 °C, following the natural temperature regime. The results of these feeding trials demonstrate a direct correlation between rising temperature and increasing food intake for water temperatures exceeding 8 °C. Food intake is further influenced by the variety of food items available at any one time. The results also confirm that Astacus astacus has a strong preference for fish and that alternation of food types has an impact on consumption. Our results prompt the following recommendations for optimized feeding conditions of crayfish in captivity prior to their release: (1 a balanced diet containing not only plant tissue but also a significant proportion of animal tissue and (2 the amount of available food must be adjusted according to the carapace length of the crayfish.

  3. Minimizing Risks of Invasive Alien Plant Species in Tropical Production Forest Management

    Directory of Open Access Journals (Sweden)

    Michael Padmanaba

    2014-08-01

    Full Text Available Timber production is the most pervasive human impact on tropical forests, but studies of logging impacts have largely focused on timber species and vertebrates. This review focuses on the risk from invasive alien plant species, which has been frequently neglected in production forest management in the tropics. Our literature search resulted in 114 publications with relevant information, including books, book chapters, reports and papers. Examples of both invasions by aliens into tropical production forests and plantation forests as sources of invasions are presented. We discuss species traits and processes affecting spread and invasion, and silvicultural practices that favor invasions. We also highlight potential impacts of invasive plant species and discuss options for managing them in production forests. We suggest that future forestry practices need to reduce the risks of plant invasions by conducting surveillance for invasive species; minimizing canopy opening during harvesting; encouraging rapid canopy closure in plantations; minimizing the width of access roads; and ensuring that vehicles and other equipment are not transporting seeds of invasive species. Potential invasive species should not be planted within dispersal range of production forests. In invasive species management, forewarned is forearmed.

  4. Soil seed banks in plant invasions: promoting species invasiveness and long-term impakt on plant community dynamics

    Czech Academy of Sciences Publication Activity Database

    Gioria, M.; Pyšek, Petr; Moravcová, Lenka

    2012-01-01

    Roč. 84, č. 2 (2012), s. 327-350 ISSN 0032-7786 R&D Projects: GA ČR GA206/09/0563 Institutional support: RVO:67985939 Keywords : soil seed bank * plant invasions * species invasive ness Subject RIV: EF - Botanics Impact factor: 2.833, year: 2012

  5. Modeling invasive alien plant species in river systems : Interaction with native ecosystem engineers and effects on hydro-morphodynamic processes

    NARCIS (Netherlands)

    van Oorschot, M.; Kleinhans, M. G.; Geerling, G.W.; Egger, G.; Leuven, R.S.E.W.; Middelkoop, H.

    2017-01-01

    Invasive alien plant species negatively impact native plant communities by out-competing species or changing abiotic and biotic conditions in their introduced range. River systems are especially vulnerable to biological invasions, because waterways can function as invasion corridors. Understanding

  6. Impacts of invasive nonnative plant species on the rare forest herb Scutellaria montana

    Science.gov (United States)

    Sikkema, Jordan J.; Boyd, Jennifer N.

    2015-11-01

    Invasive plant species and overabundant herbivore populations have the potential to significantly impact rare plant species given their increased risk for local extirpation and extinction. We used interacting invasive species removal and grazer exclusion treatments replicated across two locations in an occurrence of rare Scutellaria montana (large-flowered skullcap) in Chattanooga, Tennessee, USA, to assess: 1) competition by invasive Ligustrum sinense (Chinese privet) and Lonicera japonica (Japanese honeysuckle) and 2) the role of invasive species in mediating Oedocoilus virginianus (white-tailed deer) grazing of S. montana. Contrary to our hypothesis that invasive species presence would suppress S. montana directly via competition, S. montana individuals experienced a seasonal increase in stem height when invasive species were intact but not when invasive species were removed. Marginally significant results indicated that invasive species may afford S. montana protection from grazers, and we suggest that invasive species also could protect S. montana from smaller herbivores and/or positively influence abiotic conditions. In contrast to growth responses, S. montana individuals protected from O. virginianus exhibited a decrease in flowering between seasons relative to unprotected plants, but invasive species did not affect this variable. Although it has been suggested that invasive plant species may negatively influence S. montana growth and fecundity, our findings do not support related concerns. As such, we suggest that invasive species eradication efforts in S. montana habitat could be more detrimental than positive due to associated disturbance. However, the low level of invasion of our study site may not be representative of potential interference in more heavily infested habitat.

  7. Toward a global information system for invasive species

    Science.gov (United States)

    Ricciardi, Anthony; Steiner, William W.M.; Mack, Richard N.; Simberloff, Daniel

    2000-01-01

    The growing frequency and impact of biological invasions worldwide threaten biodiversity, ecosystem functioning, resource availability, national economies, and human health (Ruesink et al. 1995, Simberloff 1996, Vitousek et al. 1997). Organisms are spreading into new regions at unprecedented rates. As a result, hundreds to thousands of nonindigenous species of invertebrates, vertebrates, plants, bacteria, and fungi have become established in all but the most remote areas of the planet (Vitousek et al. 1997). Recent examples are abundant and, in some cases, alarming. Cholera bacteria and toxic dinoflagellates have been discovered in the ballast waters of cargo ships (McCarthy and Khambaty 1994, Hallegraeff 1998). Asian tiger mosquitos—vectors of yellow fever and encephalitis—have spread to new continents in imported truck tires (Moore et al. 1988). Pasture and crop lands in Australia are being invaded by Parthenium, an aggressive Caribbean weed that causes severe allergic reactions in livestock and humans (Evans 1997). Rapid and widespread dieoffs of native freshwater mussels are occurring in the wake of the zebra mussel invasion in North America (Ricciardi et al. 1998). [[AQ4]Hardwood trees in American cities are being killed by Asian long-horned beetles introduced with wooden packing crates (Haack et al. 1997).

  8. Biological control of alien and invasive species in agriculture

    International Nuclear Information System (INIS)

    Calvitti, Maurizio; Moretti Riccardo; Lampazzi, Elena

    2015-01-01

    Agricultural production in Europe faces many challenges including limited availability of water, nitrogen input and fossil fuels. It is necessary, therefore, to identify methods of production and new technologies to increase the efficiency of the primary systems, guaranteeing amount of food, quality, safety and eco-sustainability . One of the most important aspects, though often undervalued in relation to the food chain, is the adversity of biological management of agricultural crops due to pests, pathogens or fitomizi with potential invasive already present in the territory or of recent origin alien. In this context, two main objectives should be implemented at the same time reduce production losses and protect the agro-ecosystem. To meet these expectations, as of January 1, 2015 all farms in the European Union countries are bound to the application of the Integrated Defense principles, as indicated by the Directive on the sustainable use of plant protection products (128/09 / EC) .In response to this and other new entomological emergencies plant health and medical-veterinary entomologist researchers of the Laboratory sustainable management of Agro-Ecosystems in ENEA, have directed their research towards the development of innovative systems for the sustainable control of invasive species of insects is in the agricultural sector that health. [it

  9. Distribution patterns of invasive alien species in Alabama, USA

    Directory of Open Access Journals (Sweden)

    Xiongwen Chen

    2012-12-01

    Full Text Available Invasive alien species (IAS cause environmental and economical problems. How to effectively manage all IAS at a large area is a challenge.Hypotheses about IAS (such as the “human activity” hypothesis, the “biotic acceptance” and the “biotic resistance” have been proposedfrom numerous studies. Here the state of Alabama in USA, widely occupied by IAS, is used as a case study for characterizing the emergentpatterns of IAS. The results indicate that most IAS are located in metropolitan areas and in the Black Belt area which is a historical intensiveland use area. There are positive relationships between the richness of IAS and the change of human population, the species richness and thenumber of endangered species, as well as the total road length and farmland area across Alabama. This study partially supports the abovethree hypotheses and provides a general pattern of local IAS. Based on possible processes related with IAS, some implications forstrategically managing local IAS are discussed.

  10. A review of operations research models in invasive species management: state of the art, challenges, and future directions

    Science.gov (United States)

    İ. Esra Büyüktahtakın; Robert G. Haight

    2017-01-01

    Invasive species are a major threat to the economy, the environment, health, and thus human well-being. The international community, including the United Nations' Global Invasive Species Program (GISP), National Invasive Species Council (NISC), and Center for Invasive Species Management (CISM), has called for a rapid control of invaders in order to minimize their...

  11. The Global Invasive Species Information Network: contributing to GEO Task BI-07-01b

    Science.gov (United States)

    Graham, J.; Morisette, J. T.; Simpson, A.

    2009-12-01

    Invasive alien species (IAS) threaten biodiversity and exert a tremendous cost on society for IAS prevention and eradication. They endanger natural ecosystem functioning and seriously impact biodiversity and agricultural production. The task definition for the GEO task BI-07-01b: Invasive Species Monitoring System is to characterize, monitor, and predict changes in the distribution of invasive species. This includes characterizing the current requirements and capacity for invasive species monitoring and developing strategies for implementing cross-search functionality among existing online invasive species information systems from around the globe. The Task is being coordinated by members of the Global Invasive Species Information Network (GISIN) and their partners. Information on GISIN and a prototype of the network is available at www.gisin.org. This talk will report on the current status of GISIN and review how researchers can either contribute to or utilize data from this network.

  12. Fishes, mussels, crayfishes, and aquatic habitats of the Hoosier-Shawnee ecological assessment area

    Science.gov (United States)

    M. Burr Brooks; Justin T. Sipiorski; Matthew R. Thomas; Kevin S. Cummings; Christopher A. Taylor

    2004-01-01

    The Hoosier-Shawnee Ecological Assessment Area, part of the Coastal Plain and Interior Low Plateau physiographic provinces, includes 194 native fish species, 76 native mussel species, and 34 native crayfish species. Five of the subregions (e.g., Mississippi Embayment) that make up the assessment area were recently ranked as either globally or bioregionally outstanding...

  13. Teaching Farmers and Commercial Pesticide Applicators about Invasive Species in Pesticide Training Workshops

    Science.gov (United States)

    Wyatt, Gary J.; Herzfeld, Dean; Haugen-Brown, Tana

    2015-01-01

    Farmers and agricultural professionals who are aware of species likely to invade agricultural landscapes can be active participants in efforts to detect invasive species. To reach this audience we created a short invasive species program and added it to the existing and required pesticide applicator recertification workshops. We highlighted four…

  14. The challenge of modelling and mapping the future distribution and impact of invasive alien species

    Science.gov (United States)

    Robert C. Venette

    2015-01-01

    Invasions from alien species can jeopardize the economic, environmental or social benefits derived from biological systems. Biosecurity measures seek to protect those systems from accidental or intentional introductions of species that might become injurious. Pest risk maps convey how the probability of invasion by an alien species or the potential consequences of that...

  15. Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities

    Science.gov (United States)

    Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

    2013-01-01

    Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

  16. Herbicides: an unexpected ally for native plants in the war against invasive species

    Science.gov (United States)

    Andrea Watts; Tim Harrington; Dave Peter

    2015-01-01

    Herbicides are primarily used for protecting agricultural crops from weeds and controlling vegetation competition in newly planted forest stands. Yet for over 40 years, they have also proven useful in controlling invasive plant species in natural areas. Nonnative invasive plant species, if not controlled, can displace native species and disrupt an ecosystem by changing...

  17. Projecting future expansion of invasive species: comparing and improving methodologies for species distribution modeling.

    Science.gov (United States)

    Mainali, Kumar P; Warren, Dan L; Dhileepan, Kunjithapatham; McConnachie, Andrew; Strathie, Lorraine; Hassan, Gul; Karki, Debendra; Shrestha, Bharat B; Parmesan, Camille

    2015-12-01

    Modeling the distributions of species, especially of invasive species in non-native ranges, involves multiple challenges. Here, we developed some novel approaches to species distribution modeling aimed at reducing the influences of such challenges and improving the realism of projections. We estimated species-environment relationships for Parthenium hysterophorus L. (Asteraceae) with four modeling methods run with multiple scenarios of (i) sources of occurrences and geographically isolated background ranges for absences, (ii) approaches to drawing background (absence) points, and (iii) alternate sets of predictor variables. We further tested various quantitative metrics of model evaluation against biological insight. Model projections were very sensitive to the choice of training dataset. Model accuracy was much improved using a global dataset for model training, rather than restricting data input to the species' native range. AUC score was a poor metric for model evaluation and, if used alone, was not a useful criterion for assessing model performance. Projections away from the sampled space (i.e., into areas of potential future invasion) were very different depending on the modeling methods used, raising questions about the reliability of ensemble projections. Generalized linear models gave very unrealistic projections far away from the training region. Models that efficiently fit the dominant pattern, but exclude highly local patterns in the dataset and capture interactions as they appear in data (e.g., boosted regression trees), improved generalization of the models. Biological knowledge of the species and its distribution was important in refining choices about the best set of projections. A post hoc test conducted on a new Parthenium dataset from Nepal validated excellent predictive performance of our 'best' model. We showed that vast stretches of currently uninvaded geographic areas on multiple continents harbor highly suitable habitats for parthenium

  18. Invasive non-native species' provision of refugia for endangered native species.

    Science.gov (United States)

    Chiba, Satoshi

    2010-08-01

    The influence of non-native species on native ecosystems is not predicted easily when interspecific interactions are complex. Species removal can result in unexpected and undesired changes to other ecosystem components. I examined whether invasive non-native species may both harm and provide refugia for endangered native species. The invasive non-native plant Casuarina stricta has damaged the native flora and caused decline of the snail fauna on the Ogasawara Islands, Japan. On Anijima in 2006 and 2009, I examined endemic land snails in the genus Ogasawarana. I compared the density of live specimens and frequency of predation scars (from black rats [Rattus rattus]) on empty shells in native vegetation and Casuarina forests. The density of land snails was greater in native vegetation than in Casuarina forests in 2006. Nevertheless, radical declines in the density of land snails occurred in native vegetation since 2006 in association with increasing predation by black rats. In contrast, abundance of Ogasawarana did not decline in the Casuarina forest, where shells with predation scars from rats were rare. As a result, the density of snails was greater in the Casuarina forest than in native vegetation. Removal of Casuarina was associated with an increased proportion of shells with predation scars from rats and a decrease in the density of Ogasawarana. The thick and dense litter of Casuarina appears to provide refugia for native land snails by protecting them from predation by rats; thus, eradication of rats should precede eradication of Casuarina. Adaptive strategies, particularly those that consider the removal order of non-native species, are crucial to minimizing the unintended effects of eradication on native species. In addition, my results suggested that in some cases a given non-native species can be used to mitigate the impacts of other non-native species on native species.

  19. High-density native-range species affects the invasive plant Chromolaena odorata more strongly than species from its invasive range.

    Science.gov (United States)

    Zheng, Yulong; Liao, Zhiyong

    2017-11-22

    Invasive plant species often form dense mono-dominant stands in areas they have invaded, while having only sparse distribution in their native ranges, and the reasons behind this phenomenon are a key point of research in invasive species biology. Differences in species composition between native and invasive ranges may contribute to the difference in distribution status. In this study, we found that the high-density condition had a more negative effect on C. odorata than the low-density condition when co-grown with neighbor plants from its native range in Mexico, while this pattern was not in evidence when it was grown with neighbors from its invasive range in China. Different competitive ability and coevolutionary history with C. odorata between native-range neighbors and invasive-range neighbors may lead to the inconsistent patterns.

  20. Research on the fundamental principles of China's marine invasive species prevention legislation.

    Science.gov (United States)

    Bai, Jiayu

    2014-12-15

    China's coastal area is severely damaged by marine invasive species. Traditional tort theory resolves issues relevant to property damage or personal injuries, through which plaintiffs cannot cope with the ecological damage caused by marine invasive species. Several defects exist within the current legal regimes, such as imperfect management systems, insufficient unified technical standards, and unsound legal responsibility systems. It is necessary to pass legislation to prevent the ecological damage caused by marine invasive species. This investigation probes the fundamental principles needed for the administration and legislation of an improved legal framework to combat the problem of invasive species within China's coastal waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The need for spatially explicit quantification of benefits in invasive-species management.

    Science.gov (United States)

    Januchowski-Hartley, Stephanie R; Adams, Vanessa M; Hermoso, Virgilio

    2018-04-01

    Worldwide, invasive species are a leading driver of environmental change across terrestrial, marine, and freshwater environments and cost billions of dollars annually in ecological damages and economic losses. Resources limit invasive-species control, and planning processes are needed to identify cost-effective solutions. Thus, studies are increasingly considering spatially variable natural and socioeconomic assets (e.g., species persistence, recreational fishing) when planning the allocation of actions for invasive-species management. There is a need to improve understanding of how such assets are considered in invasive-species management. We reviewed over 1600 studies focused on management of invasive species, including flora and fauna. Eighty-four of these studies were included in our final analysis because they focused on the prioritization of actions for invasive species management. Forty-five percent (n = 38) of these studies were based on spatial optimization methods, and 35% (n = 13) accounted for spatially variable assets. Across all 84 optimization studies considered, 27% (n = 23) explicitly accounted for spatially variable assets. Based on our findings, we further explored the potential costs and benefits to invasive species management when spatially variable assets are explicitly considered or not. To include spatially variable assets in decision-making processes that guide invasive-species management there is a need to quantify environmental responses to invasive species and to enhance understanding of potential impacts of invasive species on different natural or socioeconomic assets. We suggest these gaps could be filled by systematic reviews, quantifying invasive species impacts on native species at different periods, and broadening sources and enhancing sharing of knowledge. © 2017 Society for Conservation Biology.

  2. Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

    Science.gov (United States)

    Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

    2013-01-01

    The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

  3. Invasive species: Ocean ecosystem case studies for earth systems and environmental sciences

    Science.gov (United States)

    Schofield, Pam; Brown, Mary E.

    2016-01-01

    Marine species are increasingly transferred from areas where they are native to areas where they are not. Some nonnative species become invasive, causing undesirable impacts to environment, economy and/or human health. Nonnative marine species can be introduced through a variety of vectors, including shipping, trade, inland corridors (such as canals), and others. Effects of invasive marine species can be dramatic and irreversible. Case studies of four nonnative marine species are given (green crab, comb jelly, lionfish and Caulerpa algae).

  4. Evolutionary responses of native plant species to invasive plants: a review.

    Science.gov (United States)

    Oduor, Ayub M O

    2013-12-01

    Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

  5. Invasions by two non-native insects alter regional forest species composition and successional trajectories

    Science.gov (United States)

    Randall S. Morin; Andrew M. Liebhold

    2015-01-01

    While invasions of individual non-native phytophagous insect species are known to affect growth and mortality of host trees, little is known about how multiple invasions combine to alter forest dynamics over large regions. In this study we integrate geographical data describing historical invasion spread of the hemlock woolly adelgid, Adelges tsugae...

  6. Aliens in Transylvania: risk maps of invasive alien plant species in Central Romania

    Directory of Open Access Journals (Sweden)

    Heike Zimmermann

    2015-01-01

    Full Text Available Using the MAXENT algorithm, we developed risk maps for eight invasive plant species in southern Transylvania, Romania, a region undergoing drastic land-use changes. Our findings show that invasion risk increased with landscape heterogeneity. Roads and agricultural areas were most prone to invasion, whereas forests were least at risk.

  7. Public reaction to invasive plant species in a disturbed Colorado landscape

    Science.gov (United States)

    Michael T. Daab; Courtney G. Flint

    2010-01-01

    Invasive plant species degrade ecosystems in many ways. Controlling invasive plants is costly for government agencies, businesses, and individuals. North central Colorado is currently experiencing large-scale disturbance, and millions of acres are vulnerable to invasion because of natural and socioeconomic processes. Mountain pine beetles typically endemic to this...

  8. ECOLOGICAL CHARACTERISATION OF STREAMS IN TUSCANY (ITALY FOR THE MANAGEMENT OF THE THREATENED CRAYFISH AUSTROPOTAMOBIUS PALLIPES COMPLEX

    Directory of Open Access Journals (Sweden)

    RENAI B.

    2006-01-01

    Full Text Available Any initiative aimed at the management of a threatened species needs a good knowledge of its environmental requirements. Aims of this study were to individuate suitable areas for the reintroduction of crayfish species belonging to the Austropotamobius pallipes complex and to evaluate the causes of the local extinction in Tuscany (Italy of some populations. Between May 2003 and September 2004, we collected ecological data from 19 streams of 4 catchments, 9 watercourses where crayfish were present (WI and 10 where they were present in the recent past and absent now (WO, and we compared them. Multivariate analyses were performed using chemico-physical and biotic parameters to examine the relationships between their values and the presence of crayfish. The results did not allow us to find significant differences between the two categories of streams, suggesting their suitability for crayfish reintroduction.

  9. Inferring invasive species abundance using removal data from management actions

    Science.gov (United States)

    Davis, Amy J.; Hooten, Mevin B.; Miller, Ryan S.; Farnsworth, Matthew L.; Lewis, Jesse S.; Moxcey, Michael; Pepin, Kim M.

    2016-01-01

    Evaluation of the progress of management programs for invasive species is crucial for demonstrating impacts to stakeholders and strategic planning of resource allocation. Estimates of abundance before and after management activities can serve as a useful metric of population management programs. However, many methods of estimating population size are too labor intensive and costly to implement, posing restrictive levels of burden on operational programs. Removal models are a reliable method for estimating abundance before and after management using data from the removal activities exclusively, thus requiring no work in addition to management. We developed a Bayesian hierarchical model to estimate abundance from removal data accounting for varying levels of effort, and used simulations to assess the conditions under which reliable population estimates are obtained. We applied this model to estimate site-specific abundance of an invasive species, feral swine (Sus scrofa), using removal data from aerial gunning in 59 site/time-frame combinations (480–19,600 acres) throughout Oklahoma and Texas, USA. Simulations showed that abundance estimates were generally accurate when effective removal rates (removal rate accounting for total effort) were above 0.40. However, when abundances were small (<50) the effective removal rate needed to accurately estimates abundances was considerably higher (0.70). Based on our post-validation method, 78% of our site/time frame estimates were accurate. To use this modeling framework it is important to have multiple removals (more than three) within a time frame during which demographic changes are minimized (i.e., a closed population; ≤3 months for feral swine). Our results show that the probability of accurately estimating abundance from this model improves with increased sampling effort (8+ flight hours across the 3-month window is best) and increased removal rate. Based on the inverse relationship between inaccurate abundances and

  10. Inferring invasive species abundance using removal data from management actions.

    Science.gov (United States)

    Davis, Amy J; Hooten, Mevin B; Miller, Ryan S; Farnsworth, Matthew L; Lewis, Jesse; Moxcey, Michael; Pepin, Kim M

    2016-10-01

    Evaluation of the progress of management programs for invasive species is crucial for demonstrating impacts to stakeholders and strategic planning of resource allocation. Estimates of abundance before and after management activities can serve as a useful metric of population management programs. However, many methods of estimating population size are too labor intensive and costly to implement, posing restrictive levels of burden on operational programs. Removal models are a reliable method for estimating abundance before and after management using data from the removal activities exclusively, thus requiring no work in addition to management. We developed a Bayesian hierarchical model to estimate abundance from removal data accounting for varying levels of effort, and used simulations to assess the conditions under which reliable population estimates are obtained. We applied this model to estimate site-specific abundance of an invasive species, feral swine (Sus scrofa), using removal data from aerial gunning in 59 site/time-frame combinations (480-19,600 acres) throughout Oklahoma and Texas, USA. Simulations showed that abundance estimates were generally accurate when effective removal rates (removal rate accounting for total effort) were above 0.40. However, when abundances were small (removal rate needed to accurately estimates abundances was considerably higher (0.70). Based on our post-validation method, 78% of our site/time frame estimates were accurate. To use this modeling framework it is important to have multiple removals (more than three) within a time frame during which demographic changes are minimized (i.e., a closed population; ≤3 months for feral swine). Our results show that the probability of accurately estimating abundance from this model improves with increased sampling effort (8+ flight hours across the 3-month window is best) and increased removal rate. Based on the inverse relationship between inaccurate abundances and inaccurate removal

  11. Running a network on a shoestring: the Global Invasive Species Information Network

    Science.gov (United States)

    Jarnevich, Catherine S.; Simpson, Annie; Graham, James J; Newman, Gregory J.; Bargeron, Chuck T.

    2015-01-01

    The Global Invasive Species Information Network (GISIN) was conceptualized in 2004 to aggregate and disseminate invasive species data in a standardized way. A decade later the GISIN community has implemented a data portal and three of six GISIN data aggregation models in the GISIN data exchange Protocol, including invasive species status information, resource URLs, and occurrence data. The portal is based on a protocol developed by representatives from 15 countries and 27 organizations of the global invasive species information management community. The GISIN has 19 data providers sharing 34,343 species status records, 1,693,073 occurrences, and 15,601 resource URLs. While the GISIN's goal is to be global, much of its data and funding are provided by the United States. Several initiatives use the GISIN as their information backbone, such as the Great Lakes Early Detection Network (GLEDN) and the North American Invasive Species Network (NAISN). Here we share several success stories and organizational challenges that remain.

  12. The Bifurcation and Control of a Single-Species Fish Population Logistic Model with the Invasion of Alien Species

    OpenAIRE

    Zhang, Yi; Zhang, Qiaoling; Li, Jinghao; Zhang, Qingling

    2014-01-01

    The objective of this paper is to study systematically the bifurcation and control of a single-species fish population logistic model with the invasion of alien species based on the theory of singular system and bifurcation. It regards Spartina anglica as an invasive species, which invades the fisheries and aquaculture. Firstly, the stabilities of equilibria in this model are discussed. Moreover, the sufficient conditions for existence of the trans-critical bifurcation and the singularity ind...

  13. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits.

    Directory of Open Access Journals (Sweden)

    Günther Klonner

    Full Text Available The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value, habitat use (agricultural and ruderal habitats, occurrence under the montane belt, and propagule pressure (frequency were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties.

  14. REMOTE DETENTION OF INVASIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS

    Science.gov (United States)

    Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

  15. Ecological impact of Prosopis species invasion in Turkwel riverine forest, Kenya

    NARCIS (Netherlands)

    Muturi, G.M.; Poorter, L.; Mohren, G.M.J.; Kigomo, B.N.

    2013-01-01

    The impact of Prosopis species invasion in the Turkwel riverine forest in Kenya was investigated under three contrasting: Acacia, Prosopis and Mixed species (Acacia and Prosopis) canopies. Variation amongst canopies was assessed through soil nutrients and physical properties, tree characteristics

  16. Effects of depth and crayfish size on predation risk and foraging profitability of a lotic crayfish

    Science.gov (United States)

    Flinders, C.A.; Magoulick, D.D.

    2007-01-01

    We conducted field surveys and experiments to determine whether observed distributions of crayfish among habitats were influenced by differential resource availability, foraging profitability, and predation rates and whether these factors differed with crayfish size and habitat depth. We sampled available food resources (detritus and invertebrates) and shelter as rock substrate in deep (>50 cm) and shallow (<30 cm) habitats. We used an enclosure-exclosure experiment to examine the effects of water depth and crayfish size on crayfish biomass and survival, and to determine whether these factors affected silt accrual, algal abundance (chlorophyll a [chl a]), and detritus and invertebrate biomass (g ash-free dry mass) differently from enclosures without crayfish. We conducted tethering experiments to assess predation on small (13-17 mm carapace length [CL]) and large (23-30 mm CL) Orconectes marchandi and to determine whether predation rates differed with water depth. Invertebrate biomass was significantly greater in shallow water than in deep water, whereas detritus biomass did not differ significantly between depths. Cobble was significantly more abundant in shallow than in deep water. Depth and crayfish size had a significant interactive effect on change in size of enclosed crayfish when CL was used as a measure of size but not when biomass was used as a measure of size. CL of small crayfish increased significantly more in enclosures in shallow than in deep water, but CL of large crayfish changed very little at either depth. Silt, chl a, and detritus biomass were significantly lower on tiles in large- than in small- and no-crayfish enclosures, and invertebrate biomass was significantly lower in large- than in no-crayfish enclosures. Significantly more crayfish were consumed in deep than in shallow water regardless of crayfish size. Our results suggest that predation and resource availability might influence the depth distribution of small and large crayfish. Small

  17. Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California

    Science.gov (United States)

    Hereford, Mark E.

    2016-07-22

    The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in summer 2010 indicated that endemic Amargosa River pupfish (Cyprinodon nevadensis amargosae) and speckled dace (Rhinichthys osculus spp.) were abundant and occurred throughout the Amargosa River Canyon. The 2010 survey reported non-native red swamp crayfish (Procambarus clarkii) and western mosquitofish (Gambusia affinis) captures were significantly higher, whereas pupfish captures were lower, in areas dominated by non-native saltcedar (Tamarix ssp.). Based on the 2010 survey, it was hypothesized that the invasion of saltcedar could result in a decrease in native species. In an effort to maintain and enhance native fish populations, the Bureau of Land Management removed saltcedar from a 1,550 meter reach of stream on the Amargosa River in autumn 2014 and autumn 2015. Prior to the removal of saltcedar, a survey of fishes and crayfish using baited minnow traps was conducted in the treatment reach to serve as a baseline for future comparisons with post-saltcedar removal surveys. During the 2014 survey, 1,073 pupfish and 960 speckled dace were captured within the treatment reach. Catch per unit effort of pupfish and speckled dace in the treatment reach was less in 2014 than in 2010, although differences could be owing to seasonal variation in capture probability. Non-native mosquitofish catch per unit effort decreased from 2010 to 2014; however, the catch per unit effort of crayfish increased from 2010 to 2014. Future monitoring efforts of this reach should be conducted at the same time period to account for potential seasonal fluctuations of abundance and distribution of fishes and crayfish. A more robust study design that

  18. Phenotypic plasticity and population differentiation in an ongoing species invasion.

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    Full Text Available The ability to succeed in diverse conditions is a key factor allowing introduced species to successfully invade and spread across new areas. Two non-exclusive factors have been suggested to promote this ability: adaptive phenotypic plasticity of individuals, and the evolution of locally adapted populations in the new range. We investigated these individual and population-level factors in Polygonum cespitosum, an Asian annual that has recently become invasive in northeastern North America. We characterized individual fitness, life-history, and functional plasticity in response to two contrasting glasshouse habitat treatments (full sun/dry soil and understory shade/moist soil in 165 genotypes sampled from nine geographically separate populations representing the range of light and soil moisture conditions the species inhabits in this region. Polygonum cespitosum genotypes from these introduced-range populations expressed broadly similar plasticity patterns. In response to full sun, dry conditions, genotypes from all populations increased photosynthetic rate, water use efficiency, and allocation to root tissues, dramatically increasing reproductive fitness compared to phenotypes expressed in simulated understory shade. Although there were subtle among-population differences in mean trait values as well as in the slope of plastic responses, these population differences did not reflect local adaptation to environmental conditions measured at the population sites of origin. Instead, certain populations expressed higher fitness in both glasshouse habitat treatments. We also compared the introduced-range populations to a single population from the native Asian range, and found that the native population had delayed phenology, limited functional plasticity, and lower fitness in both experimental environments compared with the introduced-range populations. Our results indicate that the future spread of P. cespitosum in its introduced range will likely be

  19. Identification of exotic North American crayfish in Europe by DNA barcoding

    Directory of Open Access Journals (Sweden)

    Filipová L.

    2011-05-01

    Full Text Available Several alien crayfish of North American origin have become established in Europe in recent decades, but their identification is often confusing. Our aim was to verify the taxonomic status of their European populations by DNA barcoding. We sequenced the cytochrome c oxidase subunit I (COI gene fragment of individuals representing all American crayfish known from European waters, and compared the results with reference sequences from North America. Our results confirm the morphological identification of Orconectes juvenilis from a population in eastern France, and of the marbled crayfish (Marmorkrebs, i.e., a parthenogenetic form of Procambarus fallax, from south-western Germany. Sequences of most individuals of presumed Procambarus acutus from the Netherlands were similar to American P. cf. acutus, but one was divergent, closer to a sequence of a reference individual of P. cf. zonangulus. However, divergences among three American P. cf. zonangulus samples were also high, comparable to interspecific variation within cambarid species complexes. The divergence between O. immunis from Europe and America also reached values corresponding to those observed among distinct Orconectes species. Genetic variation in the American range of these crayfish should therefore be further studied. Our study shows that DNA barcoding is useful for the rapid and accurate identification of exotic crayfish in Europe, and also provides insights into overall variation within these taxa.

  20. The content of phenolics and tannins in native and invasive Solidago species

    Directory of Open Access Journals (Sweden)

    Oksana Omelchuk

    2013-04-01

    Full Text Available This paper deals with plant invasions in the Transcarpathian region of the Ukraine. Within Solidagogenus, one native (S. virgaurea and one invasive (S. canadensis species were studied by measuring contents of phenolics and tannins. The results support the enemy release hypothesis. Because the invasive species can save its energy by aborting the phenolics production, and use this energy for other processes like growth or reproduction.

  1. Antagonistic interactions between an invasive alien and a native coccinellid species may promote coexistence.

    OpenAIRE

    Hentley, W.T.; Vanbergen, A.J.; Beckerman, A.P.; Brien, M.N.; Hails, R.S.; Jones, T.H.; Johnson, S.N.

    2016-01-01

    1. Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). 2. Behavioural interactions are key components of interspecific competition between predators,yet these are often overlooked invasion processes. Here, we show how behavioural, nonlethal IGP intera...

  2. 77 FR 37064 - Request for Nominations for the Invasive Species Advisory Committee; Extension of Submission...

    Science.gov (United States)

    2012-06-20

    ... their control, and minimizing the economic, ecological, and human health impacts that invasive species... monitor impacts from invasive species; and facilitates information-sharing. The role of ISAC is to...; shipping, tourism, highways, and other transportation industries; international development and trade...

  3. Exotic annual Bromus invasions: Comparisons among species and ecoregions in the western United States [Chapter 2

    Science.gov (United States)

    Matthew L. Brooks; Cynthia S. Brown; Jeanne C. Chambers; Carla M. D' Antonio; Jon E. Keeley; Jayne Belnap

    2016-01-01

    Exotic annual Bromus species are widely recognized for their potential to invade, dominate, and alter the structure and function of ecosystems. In this chapter, we summarize the invasion potential, ecosystem threats, and management strategies for different Bromus species within each of five ecoregions of the western United States. We characterize invasion...

  4. There is no silver bullet: the value of diversification in planning invasive species surveillance

    Science.gov (United States)

    Denys Yemshanov; Frank H. Koch; Bo Lu; D. Barry Lyons; Jeffrey P. Prestemon; Taylor Scarr; Klaus Koehler

    2014-01-01

    In this study we demonstrate how the notion of diversification can be used in broad-scale resource allocation for surveillance of invasive species. We consider the problem of short-term surveillance for an invasive species in a geographical environment.Wefind the optimal allocation of surveillance resourcesamongmultiple geographical subdivisions via application of a...

  5. Invasive species change detection using artificial neural networks and CASI hyperspectral imagery

    Science.gov (United States)

    For monitoring and controlling the extent and intensity of an invasive species, a direct multi-date image classification method was applied in invasive species (saltcedar) change detection in the study area of Lovelock, Nevada. With multi-date Compact Airborne Spectrographic Imager (CASI) hyperspec...

  6. Invasive species and disturbances: Current and future roles of Forest Service Research and Development

    Science.gov (United States)

    Jim Slavicek; Allen M. Solomon

    2010-01-01

    The success of an invasive species is in large part due to favorable conditions resulting from the complex interactions among natural and anthropogenic factors such as native and nonnative pests, fires, droughts, hurricanes, wind storms, ice storms, climate warming, management practices, human travel, and trade. Reducing the negative effects of invasive species and...

  7. Genetic structure of three invasive gobiid species along the Danube-Rhine invasion corridor: similar distributions, different histories

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Bryja, Josef; Ondračková, Markéta; Mendel, Jan; Jurajda, Pavel

    2017-01-01

    Roč. 12, č. 4 (2017), s. 551-564 ISSN 1798-6540 R&D Projects: GA ČR(CZ) GAP505/11/1768; GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : invasive species * Gobiidae * mitochondrial DNA haplotypes * invasion genetics * microsatellites Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 2.069, year: 2016

  8. Low genetic diversity despite multiple introductions of the invasive plant species Impatiens glandulifera in Europe.

    Science.gov (United States)

    Hagenblad, Jenny; Hülskötter, Jennifer; Acharya, Kamal Prasad; Brunet, Jörg; Chabrerie, Olivier; Cousins, Sara A O; Dar, Pervaiz A; Diekmann, Martin; De Frenne, Pieter; Hermy, Martin; Jamoneau, Aurélien; Kolb, Annette; Lemke, Isgard; Plue, Jan; Reshi, Zafar A; Graae, Bente Jessen

    2015-08-20

    Invasive species can be a major threat to native biodiversity and the number of invasive plant species is increasing across the globe. Population genetic studies of invasive species can provide key insights into their invasion history and ensuing evolution, but also for their control. Here we genetically characterise populations of Impatiens glandulifera, an invasive plant in Europe that can have a major impact on native plant communities. We compared populations from the species' native range in Kashmir, India, to those in its invaded range, along a latitudinal gradient in Europe. For comparison, the results from 39 other studies of genetic diversity in invasive species were collated. Our results suggest that I. glandulifera was established in the wild in Europe at least twice, from an area outside of our Kashmir study area. Our results further revealed that the genetic diversity in invasive populations of I. glandulifera is unusually low compared to native populations, in particular when compared to other invasive species. Genetic drift rather than mutation seems to have played a role in differentiating populations in Europe. We find evidence of limitations to local gene flow after introduction to Europe, but somewhat less restrictions in the native range. I. glandulifera populations with significant inbreeding were only found in the species' native range and invasive species in general showed no increase in inbreeding upon leaving their native ranges. In Europe we detect cases of migration between distantly located populations. Human activities therefore seem to, at least partially, have facilitated not only introductions, but also further spread of I. glandulifera across Europe. Although multiple introductions will facilitate the retention of genetic diversity in invasive ranges, widespread invasive species can remain genetically relatively invariant also after multiple introductions. Phenotypic plasticity may therefore be an important component of the

  9. Invasive species in the flora of the Starobilsk grass-meadow steppe (Ukraine

    Directory of Open Access Journals (Sweden)

    Kucher Oksana O.

    2015-06-01

    Full Text Available The results of an investigation of the invasive species in the flora of the Starobilsk grass-meadow steppe are presented. Check-list of alien plant has over 386 species of vascular plants of which 28 species are invasive. We have identified 6 transformer species from the invasive plants. We aggregate data on the entry, distribution history, ecology, occurrence in different plant communities, degree of their naturalization and the habitats where they occur. The leading families of invasive species are: Asteraceae. The basis for this group is presented by origin from the North America and the Mediterranean. With respect to the time of immigration, most of them are kenophytes. By the method of introduction, ksenophytes are dominated; according to the degree of naturalization epoecophytes and agriophytes dominate in this group. With regard to the characteristics of life forms, half of invasive species are terophytes. The vast majority of plants are heliophytes and xeromesophytes. Most species are found in biotopes group I: Cultivated agricultural biotopes; least of all species found in biotopes group F: Biotopes dominated by chamephytes and nanophanerophytes. Only 3 species found in biotopes group F: Biotopes dominated by chamephytesand nanophanerophytes. The maps of distribution of 28 invasive species are provided. Most of the species marked dispersed in more than 30 squares.

  10. Global threats from invasive alien species in the twenty-first century and national response capacities

    Science.gov (United States)

    Early, Regan; Bradley, Bethany A.; Dukes, Jeffrey S.; Lawler, Joshua J.; Olden, Julian D.; Blumenthal, Dana M.; Gonzalez, Patrick; Grosholz, Edwin D.; Ibañez, Ines; Miller, Luke P.; Sorte, Cascade J. B.; Tatem, Andrew J.

    2016-01-01

    Invasive alien species (IAS) threaten human livelihoods and biodiversity globally. Increasing globalization facilitates IAS arrival, and environmental changes, including climate change, facilitate IAS establishment. Here we provide the first global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluate national capacities to prevent and manage species invasions. We find that one-sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing economies and biodiversity hotspots. The dominant invasion vectors differ between high-income countries (imports, particularly of plants and pets) and low-income countries (air travel). Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion. PMID:27549569

  11. Evaluation of biomass of some invasive weed species as substrate for oyster mushroom (Pleurotus spp.) cultivation.

    Science.gov (United States)

    Mintesnot, Birara; Ayalew, Amare; Kebede, Ameha

    2014-01-15

    This study assessed the bioconversion of Agriculture wastes like invasive weeds species (Lantana camara, Prosopis juliflora, Parthenium hysterophorus) as a substrate for oyster mushroom (Pleurotus species) cultivation together with wheat straw as a control. The experiment was laid out in factorial combination of substrates and three edible oyster mushroom species in a Completely Randomized Design (CRD) with three replications. Pleurotus ostreatus gave significantly (p mushroom cultivation could contribute to alleviating ecological impact of invasive weed species while offering practical option to mitigating hunger and malnutrition in areas where the invasive weeds became dominant.

  12. Economic impacts of invasive species in forest past, present, and future

    Science.gov (United States)

    Thomas P. Holmes; Juliann E. Aukema; Betsy Von Holle; Andrew Liebhold; Erin Sills

    2009-01-01

    Biological invasions by nonnative species are a by-product of economic activities, with the vast majority of nonnative species introduced by trade and transport of products and people. Although most introduced species are relatively innocuous, a few species ultimately cause irreversible economic and ecological impacts, such as the chestnut blight that functionally...

  13. Interaction of species traits and environmental disturbance predicts invasion success of aquatic microorganisms.

    Directory of Open Access Journals (Sweden)

    Elvira Mächler

    Full Text Available Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species' identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary.

  14. Impacts of invasive plants on carbon pools depend on both species' traits and local climate.

    Science.gov (United States)

    Martin, Philip A; Newton, Adrian C; Bullock, James M

    2017-04-01

    Invasive plants can alter ecosystem properties, leading to changes in the ecosystem services on which humans depend. However, generalizing about these effects is difficult because invasive plants represent a wide range of life forms, and invaded ecosystems differ in their plant communities and abiotic conditions. We hypothesize that differences in traits between the invader and native species can be used to predict impacts and so aid generalization. We further hypothesize that environmental conditions at invaded sites modify the effect of trait differences and so combine with traits to predict invasion impacts. To test these hypotheses, we used systematic review to compile data on changes in aboveground and soil carbon pools following non-native plant invasion from studies across the World. Maximum potential height (H max ) of each species was drawn from trait databases and other sources. We used meta-regression to assess which of invasive species' H max , differences in this height trait between native and invasive plants, and climatic water deficit, a measure of water stress, were good predictors of changes in carbon pools following invasion. We found that aboveground biomass in invaded ecosystems relative to uninvaded ones increased as the value of H max of invasive relative to native species increased, but that this effect was reduced in more water stressed ecosystems. Changes in soil carbon pools were also positively correlated with the relative H max of invasive species, but were not altered by water stress. This study is one of the first to show quantitatively that the impact of invasive species on an ecosystem may depend on differences in invasive and native species' traits, rather than solely the traits of invasive species. Our study is also the first to show that the influence of trait differences can be altered by climate. Further developing our understanding of the impacts of invasive species using this framework could help researchers to identify not

  15. Integrating invasive species policies across ornamental horticulture supply chains to prevent plant invasions

    NARCIS (Netherlands)

    Hulme, Philip E.; Brundu, Giuseppe; Carboni, Marta; Dehnen-schmutz, Katharina; Dullinger, Stefan; Early, Regan; Essl, Franz; González-moreno, Pablo; Groom, Quentin J.; Kueffer, Christoph; Kühn, Ingolf; Maurel, Noëlie; Novoa, Ana; Pergl, Jan; Pyšek, Petr; Seebens, Hanno; Tanner, Rob; Touza, Julia M.; Van Kleunen, Mark; Verbrugge, Laura Nicoline Halley

    2017-01-01

    1.Ornamental horticulture is the primary pathway for invasive alien plant introductions. We critically appraise published evidence on the effectiveness of four policy instruments that tackle invasions along the horticulture supply chain: pre-border import restrictions, post-border bans, industry

  16. Citizen Science and Open Data: a Model for Invasive Alien Plant Species in Kenya's Northern Rangelands

    Science.gov (United States)

    Amirazodi, S.; Griffin, R.; Flores Cordova, A. I.; Ouko, E.; Omondi, S.; Mugo, R. M.; Farah, H.; Flores Cordova, A. I.; Adams, E. C.

    2017-12-01

    Invasive species in African savannas pose great threat to the native biodiversity and changes ecosystem functioning. In the forest sector, for instance Acacia species are important sources of fuel-wood, yet at the same time they have increased strain on water resources and shrunken forage spaces for both livestock and wildlife. In recently infested regions, invasive species can progress through the stages of introduction, establishment and dispersal to a full range. Currently there is much worldwide interest in predicting distributions of invasive species, and several organizations are faced with questions of whether and how to tackle such environmental challenges, or how to interpret predictions from the science community. Conservation practioners require mapped estimates of where species could persist in a given region, and this is associated to information about the biotope - i.e. the geographic location of the species' niche. The process of collecting species distribution data for identifying the potential distribution of the invasive species in the invaded ranges has become a challenge both in terms of resource and time allocation. This study highlights innovative approaches in crowdsourcing validation data in mapping and modelling invasive species (Acacia reficiens and Cactus) through involvement of the local communities. The general approach was to model the distribution of A. reficiens and Cactus (Opuntia Spp) using occurrence records from native range, then project the model into new regions to assess susceptibility to invasion using climatic and topographic environmental variables. The models performed better than random prediction (P 0.75.

  17. A global review of freshwater crayfish temperature tolerance, preference, and optimal growth

    Science.gov (United States)

    Westhoff, Jacob T.; Rosenberger, Amanda E.

    2016-01-01

    Conservation efforts, environmental planning, and management must account for ongoing ecosystem alteration due to a changing climate, introduced species, and shifting land use. This type of management can be facilitated by an understanding of the thermal ecology of aquatic organisms. However, information on thermal ecology for entire taxonomic groups is rarely compiled or summarized, and reviews of the science can facilitate its advancement. Crayfish are one of the most globally threatened taxa, and ongoing declines and extirpation could have serious consequences on aquatic ecosystem function due to their significant biomass and ecosystem roles. Our goal was to review the literature on thermal ecology for freshwater crayfish worldwide, with emphasis on studies that estimated temperature tolerance, temperature preference, or optimal growth. We also explored relationships between temperature metrics and species distributions. We located 56 studies containing information for at least one of those three metrics, which covered approximately 6 % of extant crayfish species worldwide. Information on one or more metrics existed for all 3 genera of Astacidae, 4 of the 12 genera of Cambaridae, and 3 of the 15 genera of Parastacidae. Investigations employed numerous methodological approaches for estimating these parameters, which restricts comparisons among and within species. The only statistically significant relationship we observed between a temperature metric and species range was a negative linear relationship between absolute latitude and optimal growth temperature. We recommend expansion of studies examining the thermal ecology of freshwater crayfish and identify and discuss methodological approaches that can improve standardization and comparability among studies.

  18. Checklist of invasive alien species in CSIR-NBRI Botanic Garden, Lucknow, India

    Directory of Open Access Journals (Sweden)

    Shilpi Singh

    2015-08-01

    Full Text Available The invasive alien species of CSIR-NBRI Botanic Garden are enumerated and their impact on the surrounding ecosystem are discussed. This study deals with the information on habit, nativity and family of plant species occurring in the area of study. A total of 103 invasive alien species under 86 genera and 36 families were recorded. Among these, the eudicotyledons represent 85 species, 69 genera and 32 families; monocotyledons represent 18 species, 17 genera and 4 families. In terms of nativity, species from Tropical America are the most dominant group with 34 species. In addition, based on life forms, herbs are dominant (88 species, followed by shrubs (8 species, climbers (4 species and trees (3 species.

  19. DNA barcoding discriminates the noxious invasive species, floating pennywort (Hydrocotyle ranunculoides L.f.), from non-invasive relatives

    NARCIS (Netherlands)

    Wiel, van de C.C.M.; Schoot, van der J.; Valkenburg, van J.L.C.H.; Duistermaat, H.; Smulders, M.J.M.

    2009-01-01

    Floating pennywort (Hydrocotyle ranunculoides L.f.), a member of the plant family Araliaceae originating from North America, is an example of an invasive aquatic species posing serious problems to the management of waterways outside of its original distribution area in Australia and Western Europe.

  20. Public attitude in the city of Belgrade towards invasive alien plant species

    Directory of Open Access Journals (Sweden)

    Tomićević Jelena

    2012-01-01

    Full Text Available Biological invasions are seen as a major threat to biodiversity at a global level, while the number of new invasions is increasing at an alarming rate. Raising the awareness of the public, academic world and policy makers about the dangers caused by invasive species, is essential for the creation of the support needed to implement and coordinate the policies necessary to address this problem. The aim of this study is to determine the level of local public awareness of the existence of these plant species, examine the public attitude towards alien invasive plant species and willingness to get involved in the prevention of their spreading. The survey was conducted in four nurseries on the territory of the City of Belgrade and the investigation dealt only with alien invasive woody plant species. Thirty customers were questioned in each of the four nurseries. The results show that local public is uninformed on the issue of invasive plant species. It is necessary to constantly and intensively raise their awareness of this issue, as well as the awareness of harmful consequences that may occur due to the uncontrolled spreading of alien invasive species. This refers not only to the population that visits the nurseries and buys the plants there and to those employed in plant production and selling, but also to the whole local public and decision makers.

  1. Can transgenerational plasticity contribute to the invasion success of annual plant species?

    Science.gov (United States)

    Fenesi, Annamária; Dyer, Andrew R; Geréd, Júliánna; Sándor, Dorottya; Ruprecht, Eszter

    2014-09-01

    Adaptive transgenerational plasticity (TGP), i.e., significantly higher fitness when maternal and offspring conditions match, might contribute to the population growth of non-native species in highly variable environments. However, comparative studies that directly test this hypothesis are lacking. Therefore, we performed a reciprocal split-brood experiment to compare TGP in response to N and water availability in single populations of two invasive (Amaranthus retroflexus, Galinsoga parviflora) and two congeneric non-invasive introduced species (Amaranthus albus, Galinsoga ciliata). We hypothesized that the transgenerational effect is adaptive: (1) in invasive species compared with non-invasive adventives, and (2) in stressful conditions compared with resource-rich environments. The phenotypic variation among offspring was generated, in large part, by our experimental treatments in the maternal generation; therefore, we demonstrated a direct TGP effect on the offspring's adult fitness. We found evidence, for the first time, that invasive and non-invasive adventive species differ regarding the expression of TGP in the adult stage, as adaptive responses were found exclusively in the invasive species. The manifestation of TGP was more explicit under resource-rich conditions; therefore, it might contribute to the population dynamics of non-native species in resource-rich sites rather than to their ecological tolerance spectra.

  2. Public attitude in the city of Belgrade towards invasive alien plant species

    OpenAIRE

    Tomićević Jelena; Grbić Mihailo; Skočajić Dragana; Radovanović Dragana

    2012-01-01

    Biological invasions are seen as a major threat to biodiversity at a global level, while the number of new invasions is increasing at an alarming rate. Raising the awareness of the public, academic world and policy makers about the dangers caused by invasive species, is essential for the creation of the support needed to implement and coordinate the policies necessary to address this problem. The aim of this study is to determine the level of local public a...

  3. Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

    Science.gov (United States)

    Gallagher, R V; Randall, R P; Leishman, M R

    2015-04-01

    The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

  4. Predicting the presence and cover of management relevant invasive plant species on protected areas.

    Science.gov (United States)

    Iacona, Gwenllian; Price, Franklin D; Armsworth, Paul R

    2016-01-15

    Invasive species are a management concern on protected areas worldwide. Conservation managers need to predict infestations of invasive plants they aim to treat if they want to plan for long term management. Many studies predict the presence of invasive species, but predictions of cover are more relevant for management. Here we examined how predictors of invasive plant presence and cover differ across species that vary in their management priority. To do so, we used data on management effort and cover of invasive plant species on central Florida protected areas. Using a zero-inflated multiple regression framework, we showed that protected area features can predict the presence and cover of the focal species but the same features rarely explain both. There were several predictors of either presence or cover that were important across multiple species. Protected areas with three days of frost per year or fewer were more likely to have occurrences of four of the six focal species. When invasive plants were present, their proportional cover was greater on small preserves for all species, and varied with surrounding household density for three species. None of the predictive features were clearly related to whether species were prioritized for management or not. Our results suggest that predictors of cover and presence can differ both within and across species but do not covary with management priority. We conclude that conservation managers need to select predictors of invasion with care as species identity can determine the relationship between predictors of presence and the more management relevant predictors of cover. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Introduced and invasive insect species in the Czech Republic and their economic and ecological impact (Insecta

    Directory of Open Access Journals (Sweden)

    Hana Šefrová

    2005-01-01

    Full Text Available A total of 383 alien insect species were registered in the Czech Republic, which represents 1.4% of local fauna. The most numerous taxonomic groups are Homoptera (116 species, 30.3%, Coleoptera (110; 28.7% and Lepidoptera (37; 9.7%. The occurrence of 200 species (52.2% are limited to closed heated spaces, casual aliens (28; 7.3% infiltrate the outdoor environment for a short term only, 36 (9.4% naturalized non-invasive species do not spread from the location of introduction, 50 (13.1% species are post-invasive and 69 (18.0% invasive. From the species registered, 61 (15.9% are stored product pests (especially Coleoptera 36 species, Psocoptera 11, and Lepidoptera 9, 50 (13.1% are plant pests indoors (especially Coccinea 33 species, Aphidinea 7, and Thysanoptera 6, 25 (i.e. 6.5% of aliens are pests in agriculture, forestry, and in ornamental cultures, 15 species (3.9% are important animal parasites, and 5 species (1.3% can affect biodiversity. Of the remaining 227 species (59.3%, no economic or ecological effects were found. The origin of most of the species living eusynanthropically is in the tropics and subtropics; of the 155 naturalized (non-invasive, post-invasive, and invasive species, 42 (27.1% originate from the Mediterranean, 36 (23.2% from North America, 28 (18.1% from Central to Southwest Asia, 14 (9.0% from East Asia, 13 (8.4% from South and Southeast Asia, with the remaining 22 species (14.2% coming from other areas.

  6. Reproductive characteristics of neophytes in the Czech Republic: traits of invasive and non-invasive species

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Lenka; Pyšek, Petr; Jarošík, Vojtěch; Havlíčková, Vendula; Zákravský, Petr

    2010-01-01

    Roč. 82, č. 4 (2010), s. 365-390 ISSN 0032-7786 R&D Projects: GA MŠk LC06073; GA ČR GA206/09/0563; GA ČR GA206/05/0323 Institutional research plan: CEZ:AV0Z60050516 Keywords : plant invasions * reproductive traits * invasiveness Subject RIV: EF - Botanics Impact factor: 2.792, year: 2010

  7. Genetic characterization of Western European noble crayfish populations (Astacus astacus) for advanced conservation management strategies

    NARCIS (Netherlands)

    Schrimpf, A.; Piscione, M.; Cammaerts, R.; Collas, M.; Herman, D.; Jung, A.; Ottburg, F.; Roessink, I.; Rollin, X.; Schulz, R.; Theissinger, K.

    2017-01-01

    One central goal of conservation biology is to conserve the genetic diversity of species in order to protect their adaptive potential. The main objective of this study was to identify management units (MUs) for the threatened noble crayfish (Astacus astacus) in Western Europe by utilizing

  8. 76 FR 18575 - Nominations of New Members to the Invasive Species Advisory Committee (ISAC)

    Science.gov (United States)

    2011-04-04

    ...; facilitates the development of a coordinated network to document, evaluate, and monitor impacts from invasive... invasive species; encourages planning and action at local, tribal, State, regional and ecosystem- based... monitoring, natural resource database design and integration, and internet-based management of conservation...

  9. Invasive species detection in Hawaiian rainforests using airborne imaging spectroscopy and LiDAR

    Science.gov (United States)

    Gregory P. Asner; David E. Knapp; Ty Kennedy-Bodoin; Matthew O. Jones; Roberta E. Martin; Joseph Boardman; Flint Hughes

    2008-01-01

    Remote sensing of invasive species is a critical component of conservation and management efforts, but reliable methods for the detection of invaders have not been widely established. In Hawaiian forests, we recently found that invasive trees often have hyperspectral signatures unique from that of native trees, but mapping based on spectral reflectance properties alone...

  10. Linking nitrogen partitioning and species abundance to invasion resistance in the Great Basin

    Science.gov (United States)

    J. J. James; K. W. Davies; R. L. Sheley; Z. T. Aanderud

    2008-01-01

    Resource partitioning has been suggested as an important mechanism of invasion resistance. The relative importance of resource partitioning for invasion resistance, however, may depend on how species abundance is distributed in the plant community. This study had two objectives. First, we quantified the degree to which one resource, nitrogen (N), is partitioned by time...

  11. Rapid assessment of the invasive status of eucalyptus species in two South African provinces

    CSIR Research Space (South Africa)

    Forsyth, GG

    2004-01-01

    Full Text Available . camaidutensis) and flooded gum (E. grandis) are clearly invasive. Surveys were not undertaken in parts of the Western Cape known to be invaded by spider gum (E. lehmannii); the invasive status of this species is well known and is not contested. Red River gum has...

  12. Exotic and invasive terrestrial and freshwater animal species in the Dutch Caribbean

    NARCIS (Netherlands)

    Buurt, van G.; Debrot, A.O.

    2011-01-01

    An overview of 72 invasive animals of the terrestrial and freshwater environments of the Dutch Caribbean, eleven of which are no longer present. All invasive animals that are principally agricultural pests and or animal and plant diseases (46 species) are excluded as these are discussed separately

  13. Do traits of invasive species influence decomposition and soil respiration of disturbed ecosystems?

    Science.gov (United States)

    Wells, A. J.; Balster, N. J.

    2009-12-01

    Large-scale landscape disturbances typically alter the terrestrial carbon cycle leading to shifts in pools of soil carbon. Restoration of disturbed landscapes with prairie vegetation has thus been practiced with the intent of increasing carbon accrual in soils. However, since disturbed soils are prone to invasion by non-native invasive species, many ecological restorations have resulted in unexpected outcomes, which may be explained by differences in plant traits such as tissue quality and biomass allocation. Typically, the tissue of invasive species has lower C:N ratios relative to native species, and consequently, faster decomposition rates, which potentially can alter the balance in soil carbon. The primary objective of this research was to compare the effects of native prairie species versus non-native invasive species on the carbon cycling within a novel environment: a recently dewatered basin in southwestern Wisconsin following dam removal. We hypothesized that a higher invasive to native species ratio would result in faster litter decomposition and a higher rate of soil respiration. To test this hypothesis, we seeded newly exposed sediments with native prairie seeds in 2005, annually collected aboveground plant biomass (by species per plot), calculated decomposition rate of native and invasive litter (underneath both canopy types), and measured soil respiration during the growing season of 2009. After four years of seeding, the aboveground biomass of the native vegetation has increased significantly (p invasive species biomass has decreased from 459 to 296 g m-2. Senesced tissue from mixed native species had a higher C:N ratio, 27:1 (43% C: 1.6% N), than tissue from mixed invasive species, 24:1 (35% C: 1.5% N). However, after 7 months, we found that the rate of decomposition depended on both litter type and plant canopy type (p invasive plant tissue had a slightly faster decomposition rate than the native litter and this rate was elevated under invasive

  14. Restoring abandoned agricultural lands in cold desert shrublands: Tradeoffs between water availability and invasive species

    Science.gov (United States)

    Jeanne C. Chambers; Eric P. Eldredge; Keirith A. Snyder; David I. Board; Tara Forbis de Queiroz; Vada Hubbard

    2014-01-01

    Restoration of abandoned agricultural lands to create resilient ecosystems in arid and semi-arid ecosystems typically requires seeding or transplanting native species, improving plant-soil-water relations, and controlling invasive species. We asked if improving water relations via irrigation or surface mulch would result in negative tradeoffs between native species...

  15. Integrating conventional classifiers with a GIS expert system to increase the accuracy of invasive species mapping

    NARCIS (Netherlands)

    Masocha, M.; Skidmore, A.K.

    2011-01-01

    Mapping the cover of invasive species using remotely sensed data alone is challenging, because many invaders occur as mid-level canopy species or as subtle understorey species and therefore contribute little to the spectral signatures captured by passive remote sensing devices. In this study, two

  16. Crayfish impact desert river ecosystem function and litter-dwelling invertebrate communities through association with novel detrital resources.

    Directory of Open Access Journals (Sweden)

    Eric K Moody

    Full Text Available Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima, but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia or hydric Fremont cottonwood (Populus fremontii and Gooding's willow (Salix goodingii. Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems.

  17. Effect of the internet commerce on dispersal modes of invasive alien species.

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M H; Moroń, Dawid; Sutherland, William J; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.

  18. Effect of the internet commerce on dispersal modes of invasive alien species.

    Directory of Open Access Journals (Sweden)

    Magdalena Lenda

    Full Text Available The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.

  19. Effect of the Internet Commerce on Dispersal Modes of Invasive Alien Species

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M. H.; Moroń, Dawid; Sutherland, William J.; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  20. Long time behavior of a PDE model for invasive species control

    KAUST Repository

    Parshad, R.D.

    2011-01-01

    The Trojan Y Chromosome strategy (TYC) is a theoretical method for eradication of invasive species. It requires constant introduction of artificial individuals into a target population, causing a shift in the sex ratio, that ultimately leads

  1. Transfer of Invasive Species Associated with the Movement of Military Equipment and Personnel

    National Research Council Canada - National Science Library

    Cofrancesco, Jr., Alfred F; Reaves, David R; Averett, Daniel E

    2007-01-01

    .... Every military unit that passes through a port of embarkation and debarkation is subjected to scrutiny and inspections to preclude the movement of invasive species from one region of the world to another...

  2. Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners.

    Science.gov (United States)

    Macel, Mirka; de Vos, Ric C H; Jansen, Jeroen J; van der Putten, Wim H; van Dam, Nicole M

    2014-07-01

    It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native congeners of the family Asteraceae. Our results showed that plant chemistry is highly species-specific and diverse among both exotic and native species. Nonetheless, the exotic species had on average a higher total number of metabolites and more species-unique metabolites compared with their native congeners. Herbivory led to an overall increase in metabolites in all plant species. Generalist herbivore performance was lower on most of the exotic species compared with the native species. We conclude that high chemical diversity and large phytochemical uniqueness of the exotic species could be indicative of biological invasion potential.

  3. Effects of Different Social and Environmental Conditions on Established Dominance Relationships in Crayfish.

    Science.gov (United States)

    Herberholz, Jens; Swierzbinski, Matthew E; Birke, Juliane M

    2016-04-01

    Like most social animals, crayfish readily form dominance relationships and linear social hierarchies when competing for limited resources. Competition often entails dyadic aggressive interactions, from which one animal emerges as the dominant and one as the subordinate. Once dominance relationships are formed, they typically remain stable for extended periods of time; thus, access to future resources is divided unequally among conspecifics. We previously showed that firmly established dominance relationships in juvenile crayfish can be disrupted by briefly adding a larger conspecific to the original pair. This finding suggested that the stability of social relationships in crayfish was highly context-dependent and more transient than previously assumed. We now report results that further identify the mechanisms underlying the destabilization of crayfish dominance relationships. We found that rank orders remained stable when conspecifics of smaller or equal size were added to the original pair, suggesting that both dominant and subordinate must be defeated by a larger crayfish in order to destabilize dominance relationships. We also found that dominance relationships remained stable when both members of the original pair were defeated by larger conspecifics in the absence of their original opponent. This showed that dominance relationships are not destabilized unless both animals experience defeat together. Lastly, we found that dominance relationships of pairs were successfully disrupted by larger intruders, although with reduced magnitude, after all chemical cues associated with earlier agonistic experiences were eliminated. These findings provide important new insights into the contextual features that regulate the stability of social dominance relationships in crayfish and probably in other species as well. © 2016 Marine Biological Laboratory.

  4. ROUNDTABLE SESSION 3: PHYLOGENY OF EUROPEAN CRAYFISH – IMPROVING THE TAXONOMY OF EUROPEAN CRAYFISH FOR A BETTER CONSERVATION

    Directory of Open Access Journals (Sweden)

    SCHULZ H. K.

    2005-07-01

    Full Text Available This paper summarizes the various themes discussed in a roundtable session on the uses and usefulness of genetics for conservation of our European crayfish heritage. After reviewing the importance of characterizing the different genetic stocks (ESU: Evolutionary Significant Units of a species, where morphological criteria used for taxonomy, are utilizable with caution, the present state of knowledge of the phylogeny of European species was determined, in particular for the genus Austropotamobius which occupies most studies. There was a lively debate on the elevation to species rank of A. italicus. The status of knowledge of the taxonomy of Astacus astacus has been presented. Finally, given a major increase in works describing the genetic variability of natural populations of European crayfish, it was evident that an up to date inventory of the different research teams in this field should be developed, for several reasons – (i to describe these teams and their managers (thus facilitating contact (ii to list the species studied and the markers used (iii to give some recommendations on standardizing the use of certain markers or genes so as to allow comparison between the results collected by the various teams, and to apply them on a broader geographic scale.

  5. Does competition for phosphate supply explain the invasion pattern of Elodea species?

    Science.gov (United States)

    Thiébaut, Gabrielle

    2005-09-01

    Two invasive aquatic plants, Elodea canadensis and Elodea nuttallii, occurred in north-eastern France. In this study, we examine the influence of phosphorus availability in soft water streams to explain the invasion pattern of exotic species (E. nuttallii and E. canadensis) compared to native plants (Callitriche platycarpa, Ranunculus peltatus). Total phosphorus was measured in these four aquatic macrophytes. Sediment total phosphorus and water-soluble reactive phosphorus were also analysed each season in 2001. Phosphorus content in the two invasive species and in R. peltatus was higher than in C. platycarpa. Elodea species are adapted to the seasonal phosphorus fluctuations as well as R. peltatus and exhibited high phosphorus storage ability. The high fluctuation availability of resources in space or/and time favoured the spread of the invasive plants and confirms the theory of invasibility of Davis et al. [2000. Fluctuating resources in plant communities: a general theory of invasibility. J. Ecol. 88, 528-534]. The eutrophication process increases the invasibility of E. nuttallii's, while inducing competition between E. nuttallii and native macrophyte species.

  6. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

    Directory of Open Access Journals (Sweden)

    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  7. Invasive species, environmental change and management, and health

    Czech Academy of Sciences Publication Activity Database

    Pyšek, Petr; Richardson, D. M.

    2010-01-01

    Roč. 35, - (2010), s. 25-57,C1,C2 ISSN 1543-5938 R&D Projects: GA MŠk 7E09053; GA MŠk LC06073 Grant - others:Evropská komise(XE) GOCE-CT-2003-506675 Institutional research plan: CEZ:AV0Z60050516 Keywords : biological invasions * impact * management Subject RIV: EF - Botanics Impact factor: 3.737, year: 2010

  8. Optimal surveillance and eradication of invasive species in heterogeneous landscapes

    Czech Academy of Sciences Publication Activity Database

    Epanchin-Niell, R. S.; Haight, R. G.; Berec, Luděk; Kean, J. M.; Liebhold, A. M.

    2012-01-01

    Roč. 15, č. 8 (2012), s. 803-812 ISSN 1461-023X Grant - others:National Science Foundation(US) DEB-0553768; USDA PREISM(US) 58-7000-7-0088 Institutional research plan: CEZ:AV0Z50070508 Keywords : biological invasions * cost efficient * detection Subject RIV: EH - Ecology, Behaviour Impact factor: 17.949, year: 2012 http://onlinelibrary.wiley.com/doi/10.1111/j.1461-0248.2012.01800.x/pdf

  9. Mycorrhizal status helps explain invasion success of alien plant species

    Czech Academy of Sciences Publication Activity Database

    Menzel, A.; Hempel, S.; Klotz, S.; Moora, M.; Pyšek, Petr; Rillig, M. C.; Zobel, M.; Kühn, I.

    2017-01-01

    Roč. 98, č. 1 (2017), s. 92-102 ISSN 0012-9658 R&D Projects: GA ČR GB14-36079G Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : plant invasion * mycorrhiza * naturalization Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.809, year: 2016

  10. What determines positive, neutral, and negative impacts of Solidago canadensis invasion on native plant species richness?

    Science.gov (United States)

    Dong, Li-Jia; Yu, Hong-Wei; He, Wei-Ming

    2015-11-17

    Whether plant invasions pose a great threat to native plant diversity is still hotly debated due to conflicting findings. More importantly, we know little about the mechanisms of invasion impacts on native plant richness. We examined how Solidago canadensis invasion influenced native plants using data from 291 pairs of invaded and uninvaded plots covering an entire invaded range, and quantified the relative contributions of climate, recipient communities, and S. canadensis to invasion impacts. There were three types of invasion consequences for native plant species richness (i.e., positive, neutral, and negative impacts). Overall, the relative contributions of recipient communities, S. canadensis and climate to invasion impacts were 71.39%, 21.46% and 7.15%, respectively; furthermore, the roles of recipient communities, S. canadensis and climate were largely ascribed to plant diversity, density and cover, and precipitation. In terms of direct effects, invasion impacts were negatively linked to temperature and native plant communities, and positively to precipitation and soil microbes. Soil microbes were crucial in the network of indirect effects on invasion impacts. These findings suggest that the characteristics of recipient communities are the most important determinants of invasion impacts and that invasion impacts may be a continuum across an entire invaded range.

  11. NASA and USGS invest in invasive species modeling to evaluate habitat for Africanized Honey Bees

    Science.gov (United States)

    2009-01-01

    Invasive non-native species, such as plants, animals, and pathogens, have long been an interest to the U.S. Geological Survey (USGS) and NASA. Invasive species cause harm to our economy (around $120 B/year), the environment (e.g., replacing native biodiversity, forest pathogens negatively affecting carbon storage), and human health (e.g., plague, West Nile virus). Five years ago, the USGS and NASA formed a partnership to improve ecological forecasting capabilities for the early detection and containment of the highest priority invasive species. Scientists from NASA Goddard Space Flight Center (GSFC) and the Fort Collins Science Center developed a longterm strategy to integrate remote sensing capabilities, high-performance computing capabilities and new spatial modeling techniques to advance the science of ecological invasions [Schnase et al., 2002].

  12. Federated or cached searches: providing expected performance from multiple invasive species databases

    Science.gov (United States)

    Graham, Jim; Jarnevich, Catherine S.; Simpson, Annie; Newman, Gregory J.; Stohlgren, Thomas J.

    2011-01-01

    Invasive species are a universal global problem, but the information to identify them, manage them, and prevent invasions is stored around the globe in a variety of formats. The Global Invasive Species Information Network is a consortium of organizations working toward providing seamless access to these disparate databases via the Internet. A distributed network of databases can be created using the Internet and a standard web service protocol. There are two options to provide this integration. First, federated searches are being proposed to allow users to search “deep” web documents such as databases for invasive species. A second method is to create a cache of data from the databases for searching. We compare these two methods, and show that federated searches will not provide the performance and flexibility required from users and a central cache of the datum are required to improve performance.

  13. Exotic annual Bromus invasions: comparisons among species and ecoregions in the western United States

    Science.gov (United States)

    Brooks, Matthew L.; Brown, Cynthia S.; Chambers, Jeanne C.; D'Antonio, Carla M.; Keeley, Jon E.; Belnap, Jayne

    2016-01-01

    Exotic annual Bromus species are widely recognized for their potential to invade, dominate, and alter the structure and function of ecosystems. In this chapter, we summarize the invasion potential, ecosystem threats, and management strategies for different Bromus species within each of five ecoregions of the western United States. We characterize invasion potential and threats in terms of ecosystem resistance to Bromus invasion and ecosystem resilience to disturbance with an emphasis on the importance of fi re regimes. We also explain how soil temperature and moisture regimes can be linked to patterns of resistance and resilience and provide a conceptual framework that can be used to evaluate the relative potential for invasion and ecological impact of the dominant exotic annual Bromus species in the western United States.

  14. Identifying knowledge gaps for gene drive research to control invasive animal species: The next CRISPR step

    Directory of Open Access Journals (Sweden)

    Dorian Moro

    2018-01-01

    Full Text Available Invasive animals have been linked to the extinctions of native wildlife, and to significant agricultural financial losses or impacts. Current approaches to control invasive species require ongoing resources and management over large geographic scales, and often result in the short-term suppression of populations. New and innovative approaches are warranted. Recently, the RNA guided gene drive system based on CRISPR/Cas9 is being proposed as a potential gene editing tool that could be used by wildlife managers as a non-lethal addition or alternative to help reduce pest animal populations. While regulatory control and social acceptance are crucial issues that must be addressed, there is an opportunity now to identify the knowledge and research gaps that exist for some important invasive species. Here we systematically determine the knowledge gaps for pest species for which gene drives could potentially be applied. We apply a conceptual ecological risk framework within the gene drive context within an Australian environment to identify key requirements for undertaking work on seven exemplar invasive species in Australia. This framework allows an evaluation of the potential research on an invasive species of interest and within a gene drive and risk context. We consider the currently available biological, genetic and ecological information for the house mouse, European red fox, feral cat, European rabbit, cane toad, black rat and European starling to evaluate knowledge gaps and identify candidate species for future research. We discuss these findings in the context of future thematic areas of research worth pursuing in preparation for a more formal assessment of the use of gene drives as a novel strategy for the control of these and other invasive species. Keywords: Invasive species, Gene drive, CRISPR, Pest management, Islands

  15. Clarifying values, risk perceptions, and attitudes to resolve or avoid social conflicts in invasive species management.

    Science.gov (United States)

    Estévez, Rodrigo A; Anderson, Christopher B; Pizarro, J Cristobal; Burgman, Mark A

    2015-02-01

    Decision makers and researchers recognize the need to effectively confront the social dimensions and conflicts inherent to invasive species research and management. Yet, despite numerous contentious situations that have arisen, no systematic evaluation of the literature has examined the commonalities in the patterns and types of these emergent social issues. Using social and ecological keywords, we reviewed trends in the social dimensions of invasive species research and management and the sources and potential solutions to problems and conflicts that arise around invasive species. We integrated components of cognitive hierarchy theory and risk perceptions theory to provide a conceptual framework to identify, distinguish, and provide understanding of the driving factors underlying disputes associated with invasive species. In the ISI Web of Science database, we found 15,915 peer-reviewed publications on biological invasions, 124 of which included social dimensions of this phenomenon. Of these 124, 28 studies described specific contentious situations. Social approaches to biological invasions have emerged largely in the last decade and have focused on both environmental social sciences and resource management. Despite being distributed in a range of journals, these 124 articles were concentrated mostly in ecology and conservation-oriented outlets. We found that conflicts surrounding invasive species arose based largely on differences in value systems and to a lesser extent stakeholder and decision maker's risk perceptions. To confront or avoid such situations, we suggest integrating the plurality of environmental values into invasive species research and management via structured decision making techniques, which enhance effective risk communication that promotes trust and confidence between stakeholders and decision makers. © 2014 Society for Conservation Biology.

  16. Competitive interactions between native and invasive exotic plant species are altered under elevated carbon dioxide.

    Science.gov (United States)

    Manea, Anthony; Leishman, Michelle R

    2011-03-01

    We hypothesized that the greater competitive ability of invasive exotic plants relative to native plants would increase under elevated CO(2) because they typically have traits that confer the ability for fast growth when resources are not limiting and thus are likely to be more responsive to elevated CO(2). A series of competition experiments under ambient and elevated CO(2) glasshouse conditions were conducted to determine an index of relative competition intensity for 14 native-invasive exotic species-pairs. Traits including specific leaf area, leaf mass ratio, leaf area ratio, relative growth rate, net assimilation rate and root weight ratio were measured. Competitive rankings within species-pairs were not affected by CO(2) concentration: invasive exotic species were more competitive in 9 of the 14 species-pairs and native species were more competitive in the remaining 5 species-pairs, regardless of CO(2) concentration. However, there was a significant interaction between plant type and CO(2) treatment due to reduced competitive response of native species under elevated compared with ambient CO(2) conditions. Native species had significantly lower specific leaf area and leaf area ratio under elevated compared with ambient CO(2). We also compared traits of more-competitive with less-competitive species, regardless of plant type, under both CO(2) treatments. More-competitive species had smaller leaf weight ratio and leaf area ratio, and larger relative growth rate and net assimilation rate under both ambient and elevated CO(2) conditions. These results suggest that growth and allocation traits can be useful predictors of the outcome of competitive interactions under both ambient and elevated CO(2) conditions. Under predicted future atmospheric CO(2) conditions, competitive rankings among species may not change substantially, but the relative success of invasive exotic species may be increased. Thus, under future atmospheric CO(2) conditions, the ecological and

  17. Are Invasive Species Stressful? The Glucocorticoid Profile of Native Lizards Exposed to Invasive Fire Ants Depends on the Context.

    Science.gov (United States)

    Graham, Sean P; Freidenfelds, Nicole A; Thawley, Christopher J; Robbins, Travis R; Langkilde, Tracy

    Invasive species represent a substantial threat to native species worldwide. Research on the impacts of invasive species on wild living vertebrates has focused primarily on population-level effects. The sublethal, individual-level effects of invaders may be equally important but are poorly understood. We investigated the effects of invasive fire ants (Solenopsis invicta) on the physiological stress response of a native lizard (Sceloporus undulatus) within two experimental contexts: directly exposing lizards to a fire ant attack and housing lizards with fire ants in seminatural field enclosures. Lizards directly exposed to brief attack by fire ants had elevated concentrations of the stress hormone corticosterone (CORT), suggesting that these encounters can be physiologically stressful. However, lizards exposed for longer periods to fire ants in field enclosures had lower concentrations of CORT. This may indicate that the combined effects of confinement and fire ant exposure have pushed lizards into allostatic overload. However, lizards from fire ant enclosures appeared to have intact negative feedback controls of the stress response, evidenced by functioning adrenocorticotropic hormone responsiveness and lack of suppression of innate immunity (plasma bactericidal capacity). We review previous studies examining the stress response of wild vertebrates to various anthropogenic stressors and discuss how these-in combination with our results-underscore the importance of considering context (the length, frequency, magnitude, and types of threat) when assessing these impacts.

  18. Species invasions on islands: searching for general patterns and principles

    Science.gov (United States)

    Q. Guo

    2014-01-01

    Numerous islands worldwide are being increasingly invaded by exotic species. However, the effects of invading species on native floras remain underexplored, particularly whether island biogeography theory is applicable to native, exotic, and the newly assembled floras. Inter-group comparisons across different regions or island groups through a collection of individual...

  19. Invasive exotic plant species in Sierra Nevada ecosystems

    Science.gov (United States)

    Carla M. D' Antonio; Eric L. Berlow; Karen L. Haubensak

    2004-01-01

    The Sierra Nevada is a topographically and floristically diverse region of the western United States. While it comprises only a fifth of the total land area of California, half of the native plant species in the state occur within the range. In addition, more than 400 plant species are endemic to the Sierra Nevada and many of these are listed as threatened or have...

  20. Evaluation of Integrating the Invasive Species Forecasting System to Support National Park Service Decisions on Fire Management Activities and Invasive Plant Species Control

    Science.gov (United States)

    Ma, Peter; Morisette, T.; Rodman, Ann; McClure, Craig; Pedelty, Jeff; Benson, Nate; Paintner, Kara; Most, Neal; Ullah, Asad; Cai, Weijie; hide

    2007-01-01

    The USGS and NASA, in conjunction with Colorado State University, George Mason University and other partners, have developed the Invasive Species Forecasting System (ISFS), a flexible tool that capitalizes on NASA's remote sensing resource to produce dynamic habitat maps of invasive terrestrial plant species across the United States. In 2006 ISFS was adopted to generate predictive invasive habitat maps to benefit noxious plant and fire management teams in three major National Park systems: The Greater Yellowstone Area (Yellowstone / Grand Tetons National Parks), Sequoia and Kings Canyon National Park, and interior Alaskan (between Denali, Gates of The Arctic and Yukon-Charley). One of the objectives of this study is to explore how the ISFS enhances decision support apparatus in use by National Park management teams. The first step with each park system was to work closely with park managers to select top-priority invasive species. Specific species were chosen for each study area based on management priorities, availability of observational data, and their potential for invasion after fire disturbances. Once focal species were selected, sources of presence/absence data were collected from previous surveys for each species in and around the Parks. Using logistic regression to couple presence/absence points with environmental data layers, the first round of ISFS habitat suitability maps were generated for each National Park system and presented during park visits over the summer of 2006. This first engagement provided a demonstration of what the park service can expect from ISFS and initiated the ongoing dialog on how the parks can best utilized the system to enhance their decisions related to invasive species control. During the park visits it was discovered that separate "expert opinion" maps would provide a valuable baseline to compare against the ISFS model output. Opinion maps are a means of spatially representing qualitative knowledge into a quantitative two

  1. Allelopathic assessment of selected invasive species of pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, S. [International Islamic Univ., Islamabad (Pakistan). Dept. of Bioinformatics and Biotechnology; Bangash, N. [Pir Mehr Ali Shah Arid Agriculture Univ., Peshawar (Pakistan). Dept. of Environmental Sciences; Asghar, R. [Mirpur Univ. of Science and Technology, Azad Jammu and Kashmir (Pakistan)

    2014-10-15

    Invader species are a great threat to local flora. Eight invader species of Pakistan were screened for their allelopathic activity through sandwich method. Toxic (inhibitory) and non-toxic (stimulatory) effects were assessed by recording their effect on germination and growth of lettuce. Radicle and plumule growth of lettuce were recorded at 5, 10 and 50 mg leaves concentrations of each species. Among all species the growth activity was found to be concentration dependent. Except Eutcalyptus glabra all species resulted in inhibitory effects at 5, 10 and 50 mg leaves concentrations. Xanthium strumarium and Cannabis sativa showed strong inhibitory effects on radicle and plumule growth of lettuce. Maximum inhibition was recorded at highest concentration; even growth of lettuce was stopped with 50 mg leaves concentration of C. sativa. (author)

  2. Allelopathic assessment of selected invasive species of pakistan

    International Nuclear Information System (INIS)

    Akhtar, S.

    2014-01-01

    Invader species are a great threat to local flora. Eight invader species of Pakistan were screened for their allelopathic activity through sandwich method. Toxic (inhibitory) and non-toxic (stimulatory) effects were assessed by recording their effect on germination and growth of lettuce. Radicle and plumule growth of lettuce were recorded at 5, 10 and 50 mg leaves concentrations of each species. Among all species the growth activity was found to be concentration dependent. Except Eutcalyptus glabra all species resulted in inhibitory effects at 5, 10 and 50 mg leaves concentrations. Xanthium strumarium and Cannabis sativa showed strong inhibitory effects on radicle and plumule growth of lettuce. Maximum inhibition was recorded at highest concentration; even growth of lettuce was stopped with 50 mg leaves concentration of C. sativa. (author)

  3. Identifying barriers to effective management of widespread invasive alien trees: Prosopis species (mesquite) in South Africa as a case study

    CSIR Research Space (South Africa)

    Shackleton, RT

    2016-05-01

    Full Text Available and in some cases improve the benefits that some invasive species can provide. This study assesses the barriers that hinder the effective management of widespread tree invasions, drawing insights from a case study of invasions of Prosopis species (mesquite...

  4. Public Perception of Invasive Plant Species: Assessing the Impact of Workshop Activities to Promote Young Students' Awareness

    Science.gov (United States)

    Schreck Reis, Catarina; Marchante, Helia; Freitas, Helena; Marchante, Elizabete

    2013-01-01

    Invasive species are one of the main threats to biodiversity worldwide. Even though they are identified and recognized as such by the Portuguese law, the majority of the population is not yet aware of this problem. Aiming to increase awareness about biological invasions among young students, a workshop on Invasive Plant Species was organized at…

  5. Use of exotic species in afforestation and facilitation for the establishment of biological invasion

    Directory of Open Access Journals (Sweden)

    Juliano Ricardo Fabricante

    2017-02-01

    Full Text Available This study aimed to inventory the species used in landscaping the Campus of Agricultural Sciences of the Federal University of Paraíba, Areia, PB, Brazil and to rank them according to their origin and their invasive potential. Through walks throughout the study area (active search, we cataloged all the species used in local afforestation and classified them as native or exotic. Exotic plants were also classified as to their invasive potential. Altogether, we identified 76 species belonging to 67 genera and 25 families. Of these, only 26 species were native. The results of this study are worrisome because of the large number of exotic species used for planting at the study site (50 species, including known aggressive species: Artocarpus heterophyllus Lam., Azadirachta indica A. Juss. and Leucaena leucocephala (Lam. de Wit.

  6. Herbarium specimens show patterns of fruiting phenology in native and invasive plant species across New England.

    Science.gov (United States)

    Gallinat, Amanda S; Russo, Luca; Melaas, Eli K; Willis, Charles G; Primack, Richard B

    2018-01-01

    Patterns of fruiting phenology in temperate ecosystems are poorly understood, despite the ecological importance of fruiting for animal nutrition and seed dispersal. Herbarium specimens represent an under-utilized resource for investigating geographical and climatic factors affecting fruiting times within species, patterns in fruiting times among species, and differences between native and non-native invasive species. We examined over 15,000 herbarium specimens, collected and housed across New England, and found 3159 specimens with ripe fruits, collected from 1849-2013. We examined patterns in fruiting phenology among 37 native and 18 invasive woody plant species common to New England. We compared fruiting dates between native and invasive species, and analyzed how fruiting phenology varies with temperature, space, and time. Spring temperature and year explained a small but significant amount of the variation in fruiting dates. Accounting for the moderate phylogenetic signal in fruiting phenology, invasive species fruited 26 days later on average than native species, with significantly greater standard deviations. Herbarium specimens can be used to detect patterns in fruiting times among species. However, the amount of intraspecific variation in fruiting times explained by temporal, geographic, and climatic predictors is small, due to a combination of low temporal resolution of fruiting specimens and the protracted nature of fruiting. Later fruiting times in invasive species, combined with delays in autumn bird migrations in New England, may increase the likelihood that migratory birds will consume and disperse invasive seeds in New England later into the year. © 2018 Botanical Society of America.

  7. Housing is positively associated with invasive exotic plant species richness in New England, USA.

    Science.gov (United States)

    Gavier-Pizarro, Gregorio I; Radeloff, Volker C; Stewart, Susan I; Huebner, Cynthia D; Keuler, Nicholas S

    2010-10-01

    Understanding the factors related to invasive exotic species distributions at broad spatial scales has important theoretical and management implications, because biological invasions are detrimental to many ecosystem functions and processes. Housing development facilitates invasions by disturbing land cover, introducing nonnative landscaping plants, and facilitating dispersal of propagules along roads. To evaluate relationships between housing and the distribution of invasive exotic plants, we asked (1) how strongly is housing associated with the spatial distribution of invasive exotic plants compared to other anthropogenic and environmental factors; (2) what type of housing pattern is related to the richness of invasive exotic plants; and (3) do invasive plants represent ecological traits associated with specific housing patterns? Using two types of regression analysis (best subset analysis and hierarchical partitioning analysis), we found that invasive exotic plant richness was equally or more strongly related to housing variables than to other human (e.g., mean income and roads) and environmental (e.g., topography and forest cover) variables at the county level across New England. Richness of invasive exotic plants was positively related to area of wildland-urban interface (WUI), low-density residential areas, change in number of housing units between 1940 and 2000, mean income, plant productivity (NDVI), and altitudinal range and rainfall; it was negatively related to forest area and connectivity. Plant life history traits were not strongly related to housing patterns. We expect the number of invasive exotic plants to increase as a result of future housing growth and suggest that housing development be considered a primary factor in plans to manage and monitor invasive exotic plant species.

  8. What does "local" firewood buy you? Managing the risk of invasive species introduction

    Science.gov (United States)

    Patrick C. Tobin; Andrea Diss-Torrance; Laura M. Blackburn; Brian D. Brown

    2011-01-01

    Firewood can serve as a primary vector in the transport of non-native species, particularly of wood boring insects that can be transported surreptitiously in firewood. State and Federal governments have enacted limitations on the movement of firewood as a means to limit accidental introduction of invasive species. However, it can be challenging for governments to...

  9. A rapid assessment survey of invasive species of macrobenthic invertebrates in Korean waters

    Science.gov (United States)

    Park, Chul; Kim, Sung-Tae; Hong, Jae-Sang; Choi, Keun-Hyung

    2017-09-01

    Introduced species are a growing and imminent threat to living marine resources in parts of the world's oceans. The present study is a rapid assessment survey of invasive macrobenthic invertebrate species in Korean ports. We surveyed over 40 ports around Korea during the period of May 2010 March 2013. Among the sampling sites were concrete walls, docks and associated floats, bumpers, tires, and ropes which might harbor non-native species. We found 15 invasive species as follows: one Sponge, two Bryozoans, three Mollusks, one Polychaete, four Cirripedes, and four Ascidians. Three morphologically similar species, namely X. atrata, M. galloprovincialis, and X. securis were further examined for distinctions in their morphology. Although they could be reasonably distinguished based on shell shapes, significant overlap was noted so that additional analysis may be required to correctly distinguish them. Although many of the introduced species have already spread to all three coastal areas, newly arrived invasive species showed a relatively restricted range, with a serpulid polychaete Ficopomatus enigmaticus and a mytilid bivalve Xenostrobus securis found only at a few sites on the East Coast. An exception is for Balanus perforatus, which has rapidly colonized the East coast of Korea following its introduction into the region. Successful management of invasive macrobenthic invertebrates should be established in order to contain the spread of these newly arrived species.

  10. Does global warning increase establishment rates of invasive alien species? A centurial time series analysis

    Science.gov (United States)

    Dingcheng Huang; Robert A. Haack; Runzhi. Zhang

    2011-01-01

    The establishment rate of invasive alien insect species has been increasing worldwide during the past century. This trend has been widely attributed to increased rates of international trade and associated species introductions, but rarely linked to environmental change. To better understand and manage the bioinvasion process, it is crucial to understand the...

  11. Developing thresholds of potential concern for invasive alien species: Hypotheses and concepts

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2009-03-01

    Conservation implication: In accepting that species and systems are variable, and that flux is inevitable and desirable, these TPCs developed for invasive alien species specifi cally, provide end points against which monitoring can be assessed. Once a threshold is reached, the cause of the threshold being exceeded is examined and management interventions recommended.

  12. Invasive alien species under attack: natural enemies of Harmonia axyridis in the Netherlands

    NARCIS (Netherlands)

    Raak-van den Berg, C.L.; Wielink, van P.; Jong, de P.W.; Gort, G.; Haelewaters, D.; Helder, J.; Lenteren, van J.C.

    2014-01-01

    The aphid predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is an invasive alien species in Europe and North America with negative effects on non-target species (including a decline of native ladybird populations), as well as fruit production, and human health. It is, therefore,

  13. Danger to biodiversity of High Tatras by spreading of invasive plant species

    International Nuclear Information System (INIS)

    Strba, P.; Gogolakova, A.

    2010-01-01

    The aim of our work was to analyze the current status of invasive plant species - their generic representation and current extension (horizontal and vertical extension). The authors used the method of inventory of species richness. Sites were recorded on a tourist map and GPS (Garmin).

  14. Impact of mine dumps on transport the invasive plant species to Upper Silesia

    Science.gov (United States)

    Sotkova, N.; Lokajickova, B.; Mec, J.; Svehlakova, H.; Stalmachova, B.

    2017-10-01

    Human activities significantly change the species composition in the area. The main factor of change was the mining industry, which changed the natural conditions on Upper Silesia. The anthropogenic relief of mine dumps are the main centre of alien plant in an industrial landscape. The poster deals with the state of the invasive plant species by the phyto-sociological surveys on Upper Silesia.

  15. Forecasting the impact of an invasive macrophyte species in the littoral zone through aquatic insect species composition

    Directory of Open Access Journals (Sweden)

    Hugo H. L. Saulino

    2017-11-01

    Full Text Available ABSTRACT Invasive macrophytes threaten freshwater ecosystem biodiversity. We analyzed the impact of the invasive white ginger lily (Hedychium coronarium J. König, Zingiberaceae on aquatic insect assemblages living in the littoral zone of a tropical reservoir. We took aquatic insect samples in the littoral zone on four main vegetal profile banks: white ginger monotypic bank, forest partially invaded, native macrophyte monotypic bank and riparian forest. At each vegetal bank, we measured abiotic variables such as dissolved oxygen, pH, water temperature and depth. We analyzed the aquatic insects through abundance, richness and Simpson diversity. We used the non-Metric Multidimensional Scaling (nMDS analysis to analyze the spatial distribution of each assemblage, and Analysis of similarities (ANOSIM to verify differences amongst dissimilarity distances. Additionally, we analyzed the main taxa associated with invasive macrophytes through indicator species analyses using IndVal index. We observed that the invasive macrophyte banks presented higher abundance of associated specimens, as well as lower dissimilarity of aquatic insect assemblages. Additionally, invasive macrophytes shifted the water pH and littoral depth of reservoir banks. The IndVal index indicated eight aquatic insects as indicator species. Labrundinia unicolor Silva, 2013, Ablabesmyia depaulai Neubern, 2013 and Diastatops Rambur, 1842 were indicator species on banks. We concluded that invasion of white ginger lily caused loss of shallow littoral habitat and altered the pH of the surrounding water probably by high decomposition rate and high production of plant biomass. We suggest the use of species of aquatic insects as indicator species to monitor white ginger lily impact in freshwater systems.

  16. Hurricane Activity and the Large-Scale Pattern of Spread of an Invasive Plant Species

    Science.gov (United States)

    Bhattarai, Ganesh P.; Cronin, James T.

    2014-01-01

    Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P. australis stands expanded in size by 6–35% per year. Based on tropical storm and hurricane activity over that same time period, we found that the frequency of hurricane-force winds explained 81% of the variation in P. australis growth over this broad geographic range. The expansion of P. australis stands was strongly and positively correlated with hurricane frequency. In light of the many climatic models that predict an increase in the frequency and intensity of hurricanes over the next century, these results suggest a strong link between climate change and species invasion and a challenging future ahead for the management of invasive species. PMID:24878928

  17. Analysis of the Trojan Y-Chromosome eradication strategy for an invasive species.

    Science.gov (United States)

    Wang, Xueying; Walton, Jay R; Parshad, Rana D; Storey, Katie; Boggess, May

    2014-06-01

    The Trojan Y-Chromosome (TYC) strategy, an autocidal genetic biocontrol method, has been proposed to eliminate invasive alien species. In this work, we analyze the dynamical system model of the TYC strategy, with the aim of studying the viability of the TYC eradication and control strategy of an invasive species. In particular, because the constant introduction of sex-reversed trojan females for all time is not possible in practice, there arises the question: What happens if this injection is stopped after some time? Can the invasive species recover? To answer that question, we perform a rigorous bifurcation analysis and study the basin of attraction of the recovery state and the extinction state in both the full model and a certain reduced model. In particular, we find a theoretical condition for the eradication strategy to work. Additionally, the consideration of an Allee effect and the possibility of a Turing instability are also studied in this work. Our results show that: (1) with the inclusion of an Allee effect, the number of the invasive females is not required to be very low when the introduction of the sex-reversed trojan females is stopped, and the remaining Trojan Y-Chromosome population is sufficient to induce extinction of the invasive females; (2) incorporating diffusive spatial spread does not produce a Turing instability, which would have suggested that the TYC eradication strategy might be only partially effective, leaving a patchy distribution of the invasive species.

  18. Analysis of the Trojan Y-Chromosome eradication strategy for an invasive species

    KAUST Repository

    Wang, Xueying

    2013-05-24

    The Trojan Y-Chromosome (TYC) strategy, an autocidal genetic biocontrol method, has been proposed to eliminate invasive alien species. In this work, we analyze the dynamical system model of the TYC strategy, with the aim of studying the viability of the TYC eradication and control strategy of an invasive species. In particular, because the constant introduction of sex-reversed trojan females for all time is not possible in practice, there arises the question: What happens if this injection is stopped after some time? Can the invasive species recover? To answer that question, we perform a rigorous bifurcation analysis and study the basin of attraction of the recovery state and the extinction state in both the full model and a certain reduced model. In particular, we find a theoretical condition for the eradication strategy to work. Additionally, the consideration of an Allee effect and the possibility of a Turing instability are also studied in this work. Our results show that: (1) with the inclusion of an Allee effect, the number of the invasive females is not required to be very low when the introduction of the sex-reversed trojan females is stopped, and the remaining Trojan Y-Chromosome population is sufficient to induce extinction of the invasive females; (2) incorporating diffusive spatial spread does not produce a Turing instability, which would have suggested that the TYC eradication strategy might be only partially effective, leaving a patchy distribution of the invasive species. © 2013 Springer-Verlag Berlin Heidelberg.

  19. Distribution of the invasive plant species Heracleum sosnowskyi Manden. in the Komi Republic (Russia).

    Science.gov (United States)

    Chadin, Ivan; Dalke, Igor; Zakhozhiy, Ilya; Malyshev, Ruslan; Madi, Elena; Olga Kuzivanova; Kirillov, Dmitrii; Elsakov, Vladimir

    2017-01-01

    Occurrences of the invasive plant species Heracleum sosnowskyi Manden. in the Komi Republic (northeastern part of European Russia) were recorded and published in the Global Biodiversity Information Facility (GBIF http://www.gbif.org) using the RIVR information system (http://ib.komisc.ru/add/rivr/en). RIVR stands for "Rasprostranenie Invasionnyh Vidov Rastenij" [Occurrence of Invasion Plant Species]. This citizen science project aims at collecting occurrence data about invasive plant species with the help of citizen scientists. Information can be added by any user after a simple registration (concept) process. However, the data published in GBIF are provided only by professional scientists. The total study area is approximately 19,000 km 2 . The GBIF resource contains 10894 Heracleum sosnowskyi occurrence points, each with their geographical coordinates and photographs of the plants in the locus of growth. The preliminary results of species distribution modelling on the territory of European North-East Russia presented.

  20. IUCN/SSC Invasive Species Specialist Group (ISSG)

    Science.gov (United States)

    animal species that are endemic—found nowhere else on Earth. The legacy of a unique evolutionary history of particular value to people as a source of food, medicine or livelihood... more>> 8 January

  1. Control of invasive plant species in created wetlands.

    Science.gov (United States)

    1994-01-01

    The Virginia Department of Transportation (VDOT) has been using a herbicide in the form of glyphosate for the control of unwanted species in created wetlands. Results with this particular herbicide have been somewhat mixed. It was requested that the ...

  2. Hyperspectral Time Series Analysis of Native and Invasive Species in Hawaiian Rainforests

    Directory of Open Access Journals (Sweden)

    Gregory P. Asner

    2012-08-01

    Full Text Available The unique ecosystems of the Hawaiian Islands are progressively being threatened following the introduction of exotic species. Operational implementation of remote sensing for the detection, mapping and monitoring of these biological invasions is currently hampered by a lack of knowledge on the spectral separability between native and invasive species. We used spaceborne imaging spectroscopy to analyze the seasonal dynamics of the canopy hyperspectral reflectance properties of four tree species: (i Metrosideros polymorpha, a keystone native Hawaiian species; (ii Acacia koa, a native Hawaiian nitrogen fixer; (iii the highly invasive Psidium cattleianum; and (iv Morella faya, a highly invasive nitrogen fixer. The species specific separability of the reflectance and derivative-reflectance signatures extracted from an Earth Observing-1 Hyperion time series, composed of 22 cloud-free images spanning a period of four years and was quantitatively evaluated using the Separability Index (SI. The analysis revealed that the Hawaiian native trees were universally unique from the invasive trees in their near-infrared-1 (700–1,250 nm reflectance (0.4 > SI > 1.4. Due to its higher leaf area index, invasive trees generally had a higher near-infrared reflectance. To a lesser extent, it could also be demonstrated that nitrogen-fixing trees were spectrally unique from non-fixing trees. The higher leaf nitrogen content of nitrogen-fixing trees was expressed through slightly increased separabilities in visible and shortwave-infrared reflectance wavebands (SI = 0.4. We also found phenology to be key to spectral separability analysis. As such, it was shown that the spectral separability in the near-infrared-1 reflectance between the native and invasive species groups was more expressed in summer (SI > 0.7 than in winter (SI < 0.7. The lowest separability was observed for March-July (SI < 0.3. This could be explained by the

  3. Rapid species diagnosis for invasive candidiasis using mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Carine Marinach-Patrice

    Full Text Available BACKGROUND: Matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI TOF-MS allows the identification of most bacteria and an increasing number of fungi. The potential for the highest clinical benefit of such methods would be in severe acute infections that require prompt treatment adapted to the infecting species. Our objective was to determine whether yeasts could be identified directly from a positive blood culture, avoiding the 1-3 days subculture step currently required before any therapeutic adjustments can be made. METHODOLOGY/PRINCIPAL FINDINGS: Using human blood spiked with Candida albicans to simulate blood cultures, we optimized protocols to obtain MALDI TOF-MS fingerprints where signals from blood proteins are reduced. Simulated cultures elaborated using a set of 12 strains belonging to 6 different species were then tested. Quantifiable spectral differences in the 5000-7400 Da mass range allowed to discriminate between these species and to build a reference database. The validation of the method and the statistical approach to spectral analysis were conducted using individual simulated blood cultures of 36 additional strains (six for each species. Correct identification of the species of these strains was obtained. CONCLUSIONS/SIGNIFICANCE: Direct MALDI TOF-MS analysis of aliquots from positive blood cultures allowed rapid and accurate identification of the main Candida species, thus obviating the need for sub-culturing on specific media. Subsequent to this proof-of-principle demonstration, the method can be extended to other clinically relevant yeast species, and applied to an adequate number of clinical samples in order to establish its potential to improve antimicrobial management of patients with fungemia.

  4. An ounce of prevention or a pound of cure: bioeconomic risk analysis of invasive species.

    Science.gov (United States)

    Leung, Brian; Lodge, David M; Finnoff, David; Shogren, Jason F; Lewis, Mark A; Lamberti, Gary

    2002-12-07

    Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks, however, for invasive species are lacking. We need to evaluate the risks posed by invasive species and quantify the relative merits of different management strategies (e.g. allocation of resources between prevention and control). We present a quantitative bioeconomic modelling framework to analyse risks from non-indigenous species to economic activity and the environment. The model identifies the optimal allocation of resources to prevention versus control, acceptable invasion risks and consequences of invasion to optimal investments (e.g. labour and capital). We apply the model to zebra mussels (Dreissena polymorpha), and show that society could benefit by spending up to US$324 000 year(-1) to prevent invasions into a single lake with a power plant. By contrast, the US Fish and Wildlife Service spent US$825 000 in 2001 to manage all aquatic invaders in all US lakes. Thus, greater investment in prevention is warranted.

  5. Hobbseus yalobushensis, a crayfish of intermittent streams: Biotic and habitat associations, life history characteristics, and new localities

    Science.gov (United States)

    Susan B. Adams; Blake A. Davis; Darren A. Miller

    2018-01-01

    Hobbseus yalobushensis, the Yalobusha rivulet crayfish, is a species of conservation concern because it is known from only six localities in parts of three central Mississippi counties. No studies have focused on the species since its description in 1989. Our objectives were to: (1) identify additional H. yalobushensis...

  6. Invasive rats on tropical islands: Their population biology and impacts on native species

    OpenAIRE

    Harper, Grant A.; Bunbury, Nancy

    2015-01-01

    The three most invasive rat species, black or ship rat Rattus rattus, brown or Norway rats, R. norvegicus and Pacific rat, R. exulans have been incrementally introduced to islands as humans have explored the world’s oceans. They have caused serious deleterious effects through predation and competition, and extinction of many species on tropical islands, many of which are biodiversity hotspots. All three rat species are found in virtually all habitat types, including mangrove and arid shrub la...

  7. Economic impacts of invasive species in forests: past, present, and future.

    Science.gov (United States)

    Holmes, Thomas P; Aukema, Juliann E; Von Holle, Betsy; Liebhold, Andrew; Sills, Erin

    2009-04-01

    Biological invasions by nonnative species are a by-product of economic activities, with the vast majority of nonnative species introduced by trade and transport of products and people. Although most introduced species are relatively innocuous, a few species ultimately cause irreversible economic and ecological impacts, such as the chestnut blight that functionally eradicated the American chestnut across eastern North America. Assessments of the economic costs and losses induced by nonnative forest pests are required for policy development and need to adequately account for all of the economic impacts induced by rare, highly damaging pests. To date, countrywide economic evaluations of forest-invasive species have proceeded by multiplying a unit value (price) by a physical quantity (volume of forest products damaged) to arrive at aggregate estimates of economic impacts. This approach is inadequate for policy development because (1) it ignores the dynamic impacts of biological invasions on the evolution of prices, quantities, and market behavior, and (2) it fails to account for the loss in the economic value of nonmarket ecosystem services, such as landscape aesthetics, outdoor recreation, and the knowledge that healthy forest ecosystems exist. A review of the literature leads one to anticipate that the greatest economic impacts of invasive species in forests are due to the loss of nonmarket values. We proposed that new methods for evaluating aggregate economic damages from forest-invasive species need to be developed that quantify market and nonmarket impacts at microscales that are then extended using spatially explicit models to provide aggregate estimates of impacts. Finally, policies that shift the burden of economic impacts from taxpayers and forest landowners onto parties responsible for introducing or spreading invasives, whether through the imposition of tariffs on products suspected of imposing unacceptable risks on native forest ecosystems or by requiring

  8. The assessment of invasive alien plant species removal programs ...

    African Journals Online (AJOL)

    Yusuf Adam

    a School of Agricultural, Earth and Environmental Sciences, University of ... variation of an environment due to localised extinction of endemic species. ... the abundance and impact of IAPs is still increasing (Müllerová et al., 2013). ... One of issues related to satellite image acquisition is cloud cover (Kerr & Ostrovsky, 2003).

  9. Marine Invasive Species Management: Adapting in the Arctic

    DEFF Research Database (Denmark)

    Kaiser, Brooks

    2014-01-01

    The rapid pace of climate change and increased human disturbance of ecosystems in the Arctic is bringing urgency to concern over non-native species introductions and their potential threats to the marine environment and its economic productivity, where before environmental conditions served...

  10. The assessment of invasive alien plant species removal programs ...

    African Journals Online (AJOL)

    Yusuf Adam

    Yusuf Adama, Njoya S Ngetara, Syd Ramdhanib a School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Howard ... Shaanker, 2013). These species affect human health, agriculture, forestry and biodiversity .... 2.2 Field data collection and image processing. Field data for the classification of ...

  11. Population-specific responses to an invasive species

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin; Douda, K.; Przybylski, M.; Popa, O. P.; Karbanová, E.; Matasová, K.; Rylková, K.; Polačik, Matej; Blažek, Radim; Smith, Carl

    2015-01-01

    Roč. 282, č. 1812 (2015), s. 167-174, č. článku 20151063. ISSN 0962-8452 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : alien species * Anodonta woodiana * intraspecific variation * glochidia * host–parasite dynamics * symbiosis Subject RIV: EG - Zoology Impact factor: 4.823, year: 2015

  12. Partition of ruthenium-106 between the fresh water environment and crayfish

    International Nuclear Information System (INIS)

    Berg, G.G.; Ginsberg, E.

    1976-01-01

    Crayfish of two species, Orconectes obscurus and Cambarus robustus, were identified in West Valley, New York, in streams contaminated with radioactive wastes. 106 Ru accounted for over 90% of the gamma radioactivity in specimens collected in 1972, and had higher concentrations in the crayfish than in fish from that site. Crayfish are suggested as indicator organisms for 106 Ru. In subsequent aquarium experiments, crayfish exposed to water labeled with inorganic complexes of 106 Ru concentrated the dissolved ruthenium an average of 9 x and accumulated 50% of the equilibrium body burden in approximately 10 hr, with the bulk of the isotope bound at the surface of the exoskeleton. If food was also exposed to the labeled water, uptake was faster and high concentrations were found in the digestive gland, which showed concentration factors in excess of 25 x. Releases were slower and bimodal, with approximately 10% of body burden remaining after 1 or 2 months in repeated changes of water. Data describe the partition of 106 Ru to colloidal aggregates and organically-bound sediments, and its availability for bioconcentration. (author)

  13. Mapping invasive species and spectral mixture relationships with neotropical woody formations in southeastern Brazil

    Science.gov (United States)

    Amaral, Cibele H.; Roberts, Dar A.; Almeida, Teodoro I. R.; Souza Filho, Carlos R.

    2015-10-01

    Biological invasion substantially contributes to the increasing extinction rates of native vegetative species. The remote detection and mapping of invasive species is critical for environmental monitoring. This study aims to assess the performance of a Multiple Endmember Spectral Mixture Analysis (MESMA) applied to imaging spectroscopy data for mapping Dendrocalamus sp. (bamboo) and Pinus elliottii L. (slash pine), which are invasive plant species, in a Brazilian neotropical landscape within the tropical Brazilian savanna biome. The work also investigates the spectral mixture between these exotic species and the native woody formations, including woodland savanna, submontane and alluvial seasonal semideciduous forests (SSF). Visible to Shortwave Infrared (VSWIR) imaging spectroscopy data at one-meter spatial resolution were atmospherically corrected and subset into the different spectral ranges (VIS-NIR1: 530-919 nm; and NIR2-SWIR: 1141-2352 nm). The data were further normalized via continuum removal (CR). Multiple endmember selection methods, including Interactive Endmember Selection (IES), Endmember average root mean square error (EAR), Minimum average spectral angle (MASA) and Count-based (CoB) (collectively called EMC), were employed to create endmember libraries for the targeted vegetation classes. The performance of the MESMA was assessed at the pixel and crown scales. Statistically significant differences (α = 0.05) were observed between overall accuracies that were obtained at various spectral ranges. The infrared region (IR) was critical for detecting the vegetation classes using spectral data. The invasive species endmembers exhibited spectral patterns in the IR that were not observed in the native formations. Bamboo was characterized as having a high green vegetation (GV) fraction, lower non-photosynthetic vegetation (NPV) and a low shade fraction, while pine exhibited higher NPV and shade fractions. The invasive species showed a statistically

  14. Invasive Alien Species of Terrestrial Vegetation of North-Eastern Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Sumit Srivastava

    2014-01-01

    Full Text Available The vegetational landscape of north-eastern Terai region at the foot hills of Central Himalayas is a mosaic of grassland, old-field, wasteland, and forest ecosystems. Like many other parts of the country, this region is also infested with alien intruders which not only interfere with the growth and production of food crops but also exercise adverse effects on the biodiversity of native species. The present study attempts to catalogue the invasive alien species of the terrestrial vegetation of north-eastern Uttar Pradesh especially with reference to their habit, taxonomic position, and nativity. A total of 1135 plant species within 580 genera under 119 families are so far known to occur in the region. Of these, only 149 species within 100 genera under 41 families have been found to be invasive aliens as evident from their center of origin, past history, nature of aggregation, and invasion observed under field conditions. About 80% of these invaders have been introduced from neotropics. Out of 173 invasive plants across India, this region shares 149 species, out of which 66% of species have come from Tropical America, 14% from African continent, and the rest from other countries. A better planning in the form of early identification and reporting of infestation and spread of noxious weeds is needed for their control.

  15. Selenium exposure results in reduced reproduction in an invasive ant species and altered competitive behavior for a native ant species

    International Nuclear Information System (INIS)

    De La Riva, Deborah G.; Trumble, John T.

    2016-01-01

    Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL −1 ) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL −1 ) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species. - Highlights: • Argentine ant colonies exposed to selenium had reduced fecundity compared to unexposed colonies. • Viability of offspring was negatively impacted by selenium. • Queen survival was reduced in colonies

  16. [A new method of therapy for branchiobdellosis in crayfish].

    Science.gov (United States)

    Lohniský, K

    1979-02-01

    Crayfish (Astacus fluviatilis Fabricius, 1793) were treated three times with a bath of diluted ammonia water and proflavine for four and six minutes at a temperature of 18 degrees C to get rid of the ectoparasitic worms of Branchiobdella parasita Henle, 1835; the hatching ability of the Branchiobdella parasita eggs was stopped after the treatment. No lethal effect of the bath on the crayfish of 5 to 14 cm was observed, the lethal effect on the young crayfish borne on the uropods of the female crayfish cannot be eliminated: during the baths the young crayfish died (the death rate was approximately 6% of the average fertility of crayfish); the young crayfish may have been damaged during the treatment operations with the crayfish. The bath of diluted ammonia water and proflavine may be recommended for the treatment of branchiobdellosis in crayfish to be planted, or after several-hour storage of crayfish supplied to the market. One replication of the above cycle is sufficient according to the results obtained. The ammonia content in the ammonia water depends also on the duration of storage and on the storage temperature--it can drop during the storage. Therefore the ammonia water should be used as soon as possible after the despatchment from the place of production; the ammonia content should be determined by means of titration before preparing the bath, and according to this content the dilution ratio should be adjusted.

  17. The Bifurcation and Control of a Single-Species Fish Population Logistic Model with the Invasion of Alien Species

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2014-01-01

    Full Text Available The objective of this paper is to study systematically the bifurcation and control of a single-species fish population logistic model with the invasion of alien species based on the theory of singular system and bifurcation. It regards Spartina anglica as an invasive species, which invades the fisheries and aquaculture. Firstly, the stabilities of equilibria in this model are discussed. Moreover, the sufficient conditions for existence of the trans-critical bifurcation and the singularity induced bifurcation are obtained. Secondly, the state feedback controller is designed to eliminate the unexpected singularity induced bifurcation by combining harvested effort with the purification capacity. It obviously inhibits the switch of population and makes the system stable. Finally, the numerical simulation is proposed to show the practical significance of the bifurcation and control from the biological point of view.

  18. Mediterranean species of Caulerpa are polyploid with smaller genomes in the invasive ones.

    Directory of Open Access Journals (Sweden)

    Elena Varela-Álvarez

    Full Text Available Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders. Despite many publications on the genetics and ecology of Caulerpa species, their life history and ploidy levels are still to be resolved and are the subject of large controversy. While some authors claimed that the thallus found in nature has a haplodiplobiontic life cycle with heteromorphic alternation of generations, other authors claimed a diploid or haploid life cycle with only one generation involved. DAPI-staining with image analysis and microspectrophotometry were used to estimate relative nuclear DNA contents in three species of Caulerpa from the Mediterranean, at individual, population and species levels. Results show that ploidy levels and genome size vary in these three Caulerpa species, with a reduction in genome size for the invasive ones. Caulerpa species in the Mediterranean are polyploids in different life history phases; all sampled C. taxifolia and C. racemosa var. cylindracea were in haplophasic phase, but in C. prolifera, the native species, individuals were found in both diplophasic and haplophasic phases. Different levels of endopolyploidy were found in both C. prolifera and C. racemosa var. cylindracea. Life history is elucidated for the Mediterranean C. prolifera and it is hypothesized that haplophasic dominance in C. racemosa var. cylindracea and C. taxifolia is a beneficial trait for their invasive strategies.

  19. Danger to biodiversity of High Tatras by spread of invasive plant species

    International Nuclear Information System (INIS)

    Strba, P.; Gogolakova, A.

    2010-01-01

    The aim of our work was to analyze the current status of invasive plant species - their generic representation of a current extension (horizontal and vertical extension). We have been working method inventory of species richness. Site was recorded on a tourist map and a GPS (Garmin). Populations of invasive plants are studied localities mostly small (a few individuals to hundreds of individuals), but at the high anthropogenic impacts (construction activity, excessive tourist traffic), by synantropization of habitats and concurrently with the impacts of climate change here can create important focal point of the country and pose a serious threat to biodiversity is very valuable ecosystems.

  20. Lionfish, Pterois volitans Linnaeus 1758, the complete mitochondrial DNA of an invasive species.

    Science.gov (United States)

    Del Río-Portilla, Miguel A; Vargas-Peralta, Carmen E; Machkour-M'Rabet, Salima; Hénaut, Yann; García-De-León, Francisco J

    2016-01-01

    The lionfish, Pterois volitans, native from the Indo-Pacific, has been found in Atlantic and Caribbean waters and is considered as an invasive species. Here we sequence its mitogenome (Genbank accession number KJ739816), which has a total length of 16,500 bp, and the arrangement consist of 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes and 22 transfer RNA similar to other Pteroinae subfamily (family Scorpaenidae). This mitogenome will be useful for phylogenetic and population genetic studies of this invasive species.

  1. AUTECOLOGY OF INVASIVE SPECIES Cyperus rotundus L. IN FOREST EDGE OF POHEN MOUNTAIN, BATUKAHU NATURE RESERVE, BALI, INDONESIA

    OpenAIRE

    Sutomo Sutomo; Dini Fardila

    2015-01-01

    Anthropogenic-origin forest disturbance has been known to increase the risk of invasion to native habitat. Invasive species caused problems for local ecosystems and their native species. The  research on the dynamics and autecology of invasive species Cyperus rotundus was conducted on anthropogenic disturbed Pohen mountain forest in Bali, Indonesia. Results showed significant changes in microclimatic variables from forest edge to interior. C. rotundus in Pohen mountain forest can be found in ...

  2. Species distribution modeling for the invasive raccoon dog (Nyctereutes procyonoides) in Austria and first range predictions for alpine environments

    OpenAIRE

    Duscher Tanja; Nopp-Mayr Ursula

    2017-01-01

    Species distribution models are important tools for wildlife management planning, particularly in the case of invasive species. We employed a recent framework for niche-based invasive species distribution modeling to predict the probability of presence for the invasive raccoon dog (Nyctereutes procyonoides) in Austria. The raccoon dog is an adaptive, mobile and highly reproductive Asiatic canid that has successfully invaded many parts of Europe. It is known...

  3. Invasive species triggers a massive loss of ecosystem services through a trophic cascade.

    Science.gov (United States)

    Walsh, Jake R; Carpenter, Stephen R; Vander Zanden, M Jake

    2016-04-12

    Despite growing recognition of the importance of ecosystem services and the economic and ecological harm caused by invasive species, linkages between invasions, changes in ecosystem functioning, and in turn, provisioning of ecosystem services remain poorly documented and poorly understood. We evaluate the economic impacts of an invasion that cascaded through a food web to cause substantial declines in water clarity, a valued ecosystem service. The predatory zooplankton, the spiny water flea (Bythotrephes longimanus), invaded the Laurentian Great Lakes in the 1980s and has subsequently undergone secondary spread to inland lakes, including Lake Mendota (Wisconsin), in 2009. In Lake Mendota, Bythotrephes has reached unparalleled densities compared with in other lakes, decreasing biomass of the grazer Daphnia pulicaria and causing a decline in water clarity of nearly 1 m. Time series modeling revealed that the loss in water clarity, valued at US$140 million (US$640 per household), could be reversed by a 71% reduction in phosphorus loading. A phosphorus reduction of this magnitude is estimated to cost between US$86.5 million and US$163 million (US$430-US$810 per household). Estimates of the economic effects of Great Lakes invasive species may increase considerably if cases of secondary invasions into inland lakes, such as Lake Mendota, are included. Furthermore, such extreme cases of economic damages call for increased investment in the prevention and control of invasive species to better maximize the economic benefits of such programs. Our results highlight the need to more fully incorporate ecosystem services into our analysis of invasive species impacts, management, and public policy.

  4. Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

    Science.gov (United States)

    Smith, Kimberly G.

    2006-01-01

    Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of

  5. Comparing macrophyte herbivory by introduced Louisiana crayfish ...

    African Journals Online (AJOL)

    The omnivorous Louisiana crayfish, Procambarus clarkii, has caused significant changes to macrophyte communities worldwide and may have similar negative effects in Kenya if used as a biological control agent for snails harbouring human schistosomes. Here we examine how herbivory by the introduced Louisiana ...

  6. Invasive species management restores a plant-pollinator mutualism in Hawaii

    Science.gov (United States)

    Hanna, Cause; Foote, David; Kremen, Claire

    2013-01-01

    1.The management and removal of invasive species may give rise to unanticipated changes in plant–pollinator mutualisms because they can alter the composition and functioning of plant–pollinator interactions in a variety of ways. To utilize a functional approach for invasive species management, we examined the restoration of plant–pollinator mutualisms following the large-scale removal of an invasive nectar thief and arthropod predator, Vespula pensylvanica. 2.We reduced V. pensylvanica populations in large plots managed over multiple years to examine the response of plant–pollinator mutualisms and the fruit production of a functionally important endemic Hawaiian tree species, Metrosideros polymorpha. To integrate knowledge of the invader's behaviour and the plant's mating system, we determined the efficacy of V. pensylvanica as a pollinator of M. polymorpha and quantified the dependence of M. polymorpha on animal pollination (e.g. level of self-compatibility and pollen limitation). 3.The reduction of V. pensylvanica in managed sites, when compared to unmanaged sites, resulted in a significant increase in the visitation rates of effective bee pollinators (e.g. introduced Apis mellifera and native Hylaeus spp.) and in the fruit production of M. polymorpha. 4.Apis mellifera, following the management of V. pensylvanica, appears to be acting as a substitute pollinator for M. polymorpha, replacing extinct or threatened bird and bee species in our study system. 5.Synthesis and applications. Fruit production of the native M. polymorpha was increased after management of the invasive pollinator predator V. pensylvanica; however, the main pollinators were no longer native but introduced. This research thus demonstrates the diverse impacts of introduced species on ecological function and the ambiguous role they play in restoration. We recommend incorporating ecological function and context into invasive species management as this approach may enable conservation

  7. International cooperation in the solution to trade-related invasive species risks.

    Science.gov (United States)

    Perrings, Charles; Burgiel, Stas; Lonsdale, Mark; Mooney, Harold; Williamson, Mark

    2010-05-01

    In this paper, we consider the factors behind the growth of invasive species as a global problem, and the scope for international cooperation and coordination in addressing that problem. This is limited by the terms of the various international agreements governing trade, health, and biodiversity. The default strategy in most cases has two parts: border protection and the control of or adaptation to introduced species that have escaped detection at the border. Most invasive species policy involves unilateral national defensive action as opposed to coordinated international action. We argue that an important part of the solution to the problem lies in global coordination and cooperation in the management of both pathways and sanitary and phytosanitary risks at all scales. More particularly, because invasive species are an externality of trade, transport, and travel that involve public goods, they require collective regulation of international markets that goes beyond that admitted under the World Trade Organization's (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures. We argue that it is important to bring that agreement into conformity with the International Health Regulations (IHR), and to develop an international mechanism to generate and disseminate information on invasive species risks and their impacts.

  8. Species Distribution Model for Management of an Invasive Vine in Forestlands of Eastern Texas

    Directory of Open Access Journals (Sweden)

    Hsiao-Hsuan Wang

    2015-11-01

    Full Text Available Invasive plants decrease biodiversity, modify vegetation structure, and inhibit growth and reproduction of native species. Japanese honeysuckle (Lonicera japonica Thunb. is the most prevalent invasive vine in the forestlands of eastern Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor, and test possible management strategies. We analyzed an extensive dataset collected as part of the Forest Inventory and Analysis Program of the United States Department of Agriculture (USDA Forest Service to quantify the range expansion of Japanese honeysuckle in the forestlands of eastern Texas from 2006 to 2011. We then identified potential factors influencing the likelihood of presence of Japanese honeysuckle using boosted regression trees. Our results indicated that the presence of Japanese honeysuckle on sampled plots almost doubled during this period (from 352 to 616 plots, spreading extensively, geographically. The probability of invasion was correlated with variables representing landscape conditions, climatic conditions, forest features, disturbance factors, and forest management activities. Habitats most at risk to invasion under current conditions occurred primarily in northeastern Texas, with a few invasion hotspots in the south. Estimated probabilities of invasion were reduced most by artificial site regeneration, with habitats most at risk again occurring primarily in northeastern Texas.

  9. Laboratory and field assessment of uranium trophic transfer efficiency in the crayfish Orconectes limosus fed the bivalve C. fluminea

    International Nuclear Information System (INIS)

    Simon, Olivier; Garnier-Laplace, Jacqueline

    2005-01-01

    At present, ecotoxicological information regarding the impact of natural uranium (U) on freshwater ecosystems via the trophic contamination route is scarce. We generated an experimental trophic food chain involving the prey species, Corbicula fluminea, and a predator, Orconectes limosus, for a 10-day and a 30-day feeding periods (food ration: one whole soft body/day/crayfish). We studied the efficiency of U trophic transfer and the distribution of U in the predator. During the test, we varied the quantity of dietary U (from beforehand contaminated bivalves at concentrations ranging from 0.9 ± 0.1 to 20.2 ± 9 μg/g fw provided to each crayfish over the 10 days) applying a daily feeding rate equal to 3.9 ± 0.8% fw. The efficiency of U trophic transfer from clams to crayfish varied between 1 and 13% depending on the prey exposure modalities. Accumulation of U was observed in the digestive gland but also in gills, in the muscle, and in the molt of the crayfish after trophic exposure treatments. Under high-level exposure conditions, the digestive gland was the main target-organ, however a significant accumulation was also observed in the stomach. With regard to low levels of trophic exposure, accumulation of U in gills, in the stomach, and in the digestive gland was of the same order of magnitude. Longer exposure period which incorporated a crayfish molt, resulted in a decrease of trophic transfer ratio and a modified U tissue distribution

  10. Comparative study of freshwater crayfish, Cherax spp. (crustaceae: decapoda: parastacidae) from Papua, Indonesia based on length-weight analysis

    Science.gov (United States)

    Hamidah, H.; Abinawanto, Bowolaksono, A.

    2017-07-01

    The freshwater crayfish is one of the most important fish species as the protein resources. Lake and rivers are the habitat of crayfish in Papua. Morphological characters of crayfish, such as color, total body lengths (L) and body weight (W) were influenced by the habitat. The purpose of the study, therefore, was to compare the total body length and body weight as well as the unique color of crayfish from Uter lake (Atinjo district), Seremuk river (Haha village), Baliem river (Pike village; Hubukiak district, Jayawijaya), and Baliem river (Wesaput village; Wesaput district). Length-weight (body length; LB versus wet weight; WWT) relationships were determined for male and female crayfish (Cherax spp.) The length-weight relationships of total individuals was W = 0,022215.L3,159. This regression differed significantly (R2 = 97.5 %) between locations. Both males and females exhibited positive allometric growth as statistical difference was observed in the mean of the wet weight and body length between males and females. Besides, Canonical function was subjected to determine population distribution based on length-weight data.

  11. Antagonistic interactions between an invasive alien and a native coccinellid species may promote coexistence.

    Science.gov (United States)

    Hentley, William T; Vanbergen, Adam J; Beckerman, Andrew P; Brien, Melanie N; Hails, Rosemary S; Jones, T Hefin; Johnson, Scott N

    2016-07-01

    Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). Behavioural interactions are key components of interspecific competition between predators, yet these are often overlooked invasion processes. Here, we show how behavioural, non-lethal IGP interactions might facilitate the establishment success of an invading alien species. We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata), whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterized with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non-declining C. septempunctata was unaltered by the presence of H. axyridis. Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We

  12. Abundance modelling of invasive and indigenous Culicoides species in Spain

    Directory of Open Access Journals (Sweden)

    Els Ducheyne

    2013-11-01

    Full Text Available In this paper we present a novel methodology applied in Spain to model spatial abundance patterns of potential vectors of disease at a medium spatial resolution of 5 x 5 km using a countrywide database with abundance data for five Culicoides species, random regression Forest modelling and a spatial dataset of ground measured and remotely sensed eco-climatic and environmental predictor variables. First the probability of occurrence was computed. In a second step a direct regression between the probability of occurrence and trap abundance was established to verify the linearity of the relationship. Finally the probability of occurrence was used in combination with the set of predictor variables to model abundance. In each case the variable importance of the predictors was used to biologically interpret results and to compare both model outputs, and model performance was assessed using four different accuracy measures. Results are shown for C. imicola, C. newsteadii, C. pulicaris group, C. punctatus and C. obsoletus group. In each case the probability of occurrence is a good predictor of abundance at the used spatial resolution of 5 x 5 km. In addition, the C. imicola and C. obsoletus group are highly driven by summer rainfall. The spatial pattern is inverse between the two species, indicating that the lower and upper thresholds are different. C. pulicaris group is mainly driven by temperature. The patterns for C. newsteadii and C. punctatus are less clear. It is concluded that the proposed methodology can be used as an input to transmission-infection-recovery (TIR models and R0 models. The methodology will become available to the general public as part of the VECMAPTM software.

  13. DNA barcoding discriminates the noxious invasive plant species, floating pennywort (Hydrocotyle ranunculoides L.f.), from non-invasive relatives.

    Science.gov (United States)

    VAN DE Wiel, C C M; VAN DER Schoot, J; VAN Valkenburg, J L C H; Duistermaat, H; Smulders, M J M

    2009-07-01

    Floating pennywort (Hydrocotyle ranunculoides L.f.), a member of the plant family Araliaceae originating from North America, is an example of an invasive aquatic species posing serious problems to the management of waterways outside of its original distribution area in Australia and Western Europe. As a consequence, its import was banned in the Netherlands. It can be difficult to distinguish H. ranunculoides from other species of the genus on a morphological basis. In this regard, DNA barcoding may become a good alternative once this could be performed on a routine basis. In this study, we show that it is possible to distinguish H. ranunculoides from a series of closely related congeners by using a single plastid DNA sequence, trnH-psbA. © 2009 Blackwell Publishing Ltd.

  14. Acute Upper Thermal Limits of Three Aquatic Invasive Invertebrates: Hot Water Treatment to Prevent Upstream Transport of Invasive Species

    Science.gov (United States)

    Beyer, Jessica; Moy, Philip; de Stasio, Bart

    2011-01-01

    Transport of aquatic invasive species (AIS) by boats traveling up rivers and streams is an important mechanism of secondary spread of AIS into watersheds. Because physical barriers to AIS movement also prevent navigation, alternate methods for preventing spread are necessary while allowing upstream navigation. One promising approach is to lift boats over physical barriers and then use hot water immersion to kill AIS attached to the hull, motor, or fishing gear. However, few data have been published on the acute upper thermal tolerance limits of potential invaders treated in this manner. To test the potential effectiveness of this approach for a planned boat lift on the Fox River of northeastern WI, USA, acute upper thermal limits were determined for three AIS, adult zebra mussels ( Dreissena polymorpha), quagga mussels ( Dreissena rostriformis bugensis), and spiny water fleas ( Bythotrephes longimanus) from the local area employing temperatures from 32 to 54°C and immersion times from 1 to 20 min. Mortality was determined after immersion followed by a 20-min recovery period. Immersion at 43°C for at least 5 min was required to ensure 100% mortality for all three species, but due to variability in the response by Bythotrephes a 10 min immersion would be more reliable. Overall there were no significant differences between the three species in acute upper thermal limits. Heated water can be an efficient, environmentally sound, and cost effective method of controlling AIS potentially transferred by boats, and our results should have both specific and wide-ranging applications in the prevention of the spread of aquatic invasive species.

  15. Estimating suitable environments for invasive plant species across large landscapes: A remote sensing strategy using Landsat 7 ETM+

    Science.gov (United States)

    The key to reducing ecological and economic damage caused by invasive plant species is to locate and eradicate new invasions before they threaten native biodiversity and ecological processes. We used Landsat Enhanced Thematic Mapper Plus imagery to estimate suitable environments for four invasive pl...

  16. INVASIVESNET towards an International Association for Open Knowledge on Invasive Alien Species

    Science.gov (United States)

    Lucy, Frances; Roy, Helen; Simpson, Annie; Carlton, James T.; Hanson, John Mark; Magellan, Kit; Campbell, Marnie L.; Costello, Mark J.; Pagad, Shyama; Hewitt, Chad L; McDonald, Justin; Cassey, Phillip; Thomaz, Sidinei M; Katsanevakis, Stelios; Zenetos, Argyro; Tricarico, Elena; Boggero, Angela; Groom, Quentin J.; Adriaens, Tim; Vanderhoeven, Sonia; Torchin, Mark E.; Hufbauer, Ruth A.; Fuller, Pam; Carman, Mary R; Conn, David Bruce; Vitule, Jean R. S.; Canning-Clode, João; Galil, Bella S; Ojaveer, Henn; Bailey, Sarah A; Therriault, Thomas W; Claudi, Renata; Gazda, Anna; Dick, Jaimie T A; Caffrey, Joe; Witt, Arne; Kenis, Marc; Lehtiniemi, Maiju; Helmisaari, Harry; Panov, Vadim E

    2016-01-01

    In a world where invasive alien species (IAS) are recognised as one of the major threats to biodiversity, leading scientists from five continents have come together to propose the concept of developing an international association for open knowledge and open data on IAS—termed “INVASIVESNET”. This new association will facilitate greater understanding and improved management of invasive alien species (IAS) and biological invasions globally, by developing a sustainable network of networks for effective knowledge exchange. In addition to their inclusion in the CBD Strategic Plan for Biodiversity, the increasing ecological, social, cultural and economic impacts associated with IAS have driven the development of multiple legal instruments and policies. This increases the need for greater co-ordination, co-operation, and information exchange among scientists, management, the community of practice and the public.

  17. Teaching citizen science skills online: Implications for invasive species training programs

    Science.gov (United States)

    Newman, G.; Crall, A.; Laituri, M.; Graham, J.; Stohlgren, T.; Moore, J.C.; Kodrich, K.; Holfelder, K.A.

    2010-01-01

    Citizen science programs are emerging as an efficient way to increase data collection and help monitor invasive species. Effective invasive species monitoring requires rigid data quality assurances if expensive control efforts are to be guided by volunteer data. To achieve data quality, effective online training is needed to improve field skills and reach large numbers of remote sentinel volunteers critical to early detection and rapid response. The authors evaluated the effectiveness of online static and multimedia tutorials to teach citizen science volunteers (n = 54) how to identify invasive plants; establish monitoring plots; measure percent cover; and use Global Positioning System (GPS) units. Participants trained using static and multimedia tutorials provided less (p quality, and overall program effectiveness. ?? Taylor & Francis Group, LLC.

  18. Increase in quantity and quality of suitable areas for invasive species as climate changes.

    Science.gov (United States)

    Bertelsmeier, Cleo; Luque, Gloria M; Courchamp, Franck

    2013-12-01

    As climatically suitable range projections become increasingly used to assess distributions of species, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could determine variations in the quality of potential habitat. This relative risk assessment circumvents the use of an arbitrary suitability threshold. We illustrated our method with 2 case studies on invasive ant species. We estimated invasion potential of the destroyer ant (Monomorium destructor) and the European fire ant (Myrmica rubra) on a global scale currently and by 2080 with climate change. We found that 21.1% of the world's landmass currently has a suitable climate for the destroyer ant and 16% has a suitable climate for European fire ant. Our climatic suitability index showed that both ant species would benefit from climate change, but in different ways. The size of the potential distribution increased by 35.8% for the destroyer ant. Meanwhile, the total area of potential distribution remained the same for the European fire ant (>0.05%), but the level of climatic suitability within this range increased greatly and led to an improvement in habitat quality (i.e., of invasive species' establishment likelihood). Either through quantity or quality of suitable areas, both invasive ant species are likely to increase the extent of their invasion in the future, following global climate change. Our results show that species may increase their range if either more areas become suitable or if the available areas present improved suitability. Studies in which an arbitrary suitability threshold was used may overlook changes in area quality within climatically suitable areas and as a result reach incorrect predictions. Incremento de la Cantidad y Calidad de Áreas Idóneas para Especies Invasoras a Medida que Cambia el Clima.

  19. Using Risk Assessment and Habitat Suitability Models to Prioritise Invasive Species for Management in a Changing Climate.

    Science.gov (United States)

    Chai, Shauna-Lee; Zhang, Jian; Nixon, Amy; Nielsen, Scott

    2016-01-01

    Accounting for climate change in invasive species risk assessments improves our understanding of potential future impacts and enhances our preparedness for the arrival of new non-native species. We combined traditional risk assessment for invasive species with habitat suitability modeling to assess risk to biodiversity based on climate change. We demonstrate our method by assessing the risk for 15 potentially new invasive plant species to Alberta, Canada, an area where climate change is expected to facilitate the poleward expansion of invasive species ranges. Of the 15 species assessed, the three terrestrial invasive plant species that could pose the greatest threat to Alberta's biodiversity are giant knotweed (Fallopia sachalinensis), tamarisk (Tamarix chinensis), and alkali swainsonpea (Sphaerophysa salsula). We characterise giant knotweed as 'extremely invasive', with 21 times the suitable habitat between baseline and future projected climate. Tamarisk is 'extremely invasive' with a 64% increase in suitable habitat, and alkali swainsonpea is 'highly invasive' with a 21% increase in suitable habitat. Our methodology can be used to predict and prioritise potentially new invasive species for their impact on biodiversity in the context of climate change.

  20. Using Risk Assessment and Habitat Suitability Models to Prioritise Invasive Species for Management in a Changing Climate.

    Directory of Open Access Journals (Sweden)

    Shauna-Lee Chai

    Full Text Available Accounting for climate change in invasive species risk assessments improves our understanding of potential future impacts and enhances our preparedness for the arrival of new non-native species. We combined traditional risk assessment for invasive species with habitat suitability modeling to assess risk to biodiversity based on climate change. We demonstrate our method by assessing the risk for 15 potentially new invasive plant species to Alberta, Canada, an area where climate change is expected to facilitate the poleward expansion of invasive species ranges. Of the 15 species assessed, the three terrestrial invasive plant species that could pose the greatest threat to Alberta's biodiversity are giant knotweed (Fallopia sachalinensis, tamarisk (Tamarix chinensis, and alkali swainsonpea (Sphaerophysa salsula. We characterise giant knotweed as 'extremely invasive', with 21 times the suitable habitat between baseline and future projected climate. Tamarisk is 'extremely invasive' with a 64% increase in suitable habitat, and alkali swainsonpea is 'highly invasive' with a 21% increase in suitable habitat. Our methodology can be used to predict and prioritise potentially new invasive species for their impact on biodiversity in the context of climate change.

  1. CONFIRMATION OF OCCURRENCE OF THE NARROW-CLAWED CRAYFISH ? STACUS LEPTODACTYLUS ESCHSCHOLTZ, 1823 IN THE RIVER EVROS IN GREECE

    Directory of Open Access Journals (Sweden)

    PERDIKARIS C.

    2007-04-01

    Full Text Available The narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823, is widely distributed in eastern European and western Asian countries. However, species presence in Greece was documented only by limited museum conserved specimens dating back to 1893. Recently (May 2005 several crayfish were captured in the Evros River (close to city of Didimotiho and these were identified as A. leptodactylus. The present work confirms the presence of A. leptodactylus in the Evros River still hundred and twelve years later and introduces the possibility of A. leptodactylus being indigenous to Greece.

  2. An annotated bibliography of invasive tree pathogens Sirococcus clavigignenti-juglandacearum, Phytophthora alni, and Phytophthora quercina and a regulatory policy and management practices for invasive species

    Science.gov (United States)

    T.M. Seeland; M.E. Ostry; R. Venette; J. Juzwik

    2006-01-01

    Provides a database of selected literature pertaining to the prevention, early detection and rapid response, control and management, and rehabilitation and restoration related to three invasive fungal pathogens of forest trees. Literature addressing regulatory policy and management practices for invasive species is also included.

  3. Climate, invasive species and land use drive population dynamics of a cold-water specialist

    Science.gov (United States)

    Kovach, Ryan P.; Al-Chokhachy, Robert K.; Whited, Diane C.; Schmetterling, David A.; Dux, Andrew M; Muhlfeld, Clint C.

    2017-01-01

    Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors.We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate).Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor).Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact.Synthesis and applications. Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation

  4. Analysis of the Trojan Y-Chromosome eradication strategy for an invasive species

    KAUST Repository

    Wang, Xueying; Walton, Jay R.; Parshad, Rana; Storey, Katie; Boggess, May M.

    2013-01-01

    of the TYC eradication and control strategy of an invasive species. In particular, because the constant introduction of sex-reversed trojan females for all time is not possible in practice, there arises the question: What happens if this injection is stopped

  5. Public support for invasive alien species eradication programs: insights from the Netherlands

    NARCIS (Netherlands)

    Runhaar, Hens; Vane, Maurice

    2016-01-01

    Over the last few decades, the number of invasive alien species (IAS) has increasedworldwide. IAS can have negative impacts on biodiversity, human health, and the economy. For a number of reasons, IAS policies and management schemes that have been implemented have not been sufficient to tackle the

  6. Use of DNA barcodes to identify invasive armyworm Spodoptera species in Florida

    Science.gov (United States)

    A critical component for sustaining adequate food production is the protection of local agriculture from invasive pest insects. Essential to this goal is the ability to accurately distinguish foreign from closely related domestic species, a process that has traditionally required identification of d...

  7. Pest risk maps for invasive alien species: a roadmap for improvement

    Science.gov (United States)

    Robert C. Venette; Darren J. Kriticos; Roger D. Magarey; Frank H. Koch; Richard H.A. Baker; Susan P. Worner; Nadilia N. Gomez Raboteaux; Daniel W. McKenney; Erhard J. Dobesberger; Denys Yemshanov; Paul J. De Barro; William D. Hutchison; Glenn Fowler; Tom M. Kalaris; John. Pedlar

    2010-01-01

    Pest risk maps are powerful visual communication tools to describe where invasive alien species might arrive, establish, spread, or cause harmful impacts. These maps inform strategic and tactical pest management decisions, such as potential restrictions on international trade or the design of pest surveys and domestic quarantines. Diverse methods are available to...

  8. Pest risk maps for invasive alien species: a roadmap for improvement

    Science.gov (United States)

    Robert C. Venette; Darren J. Kriticos; Roger D. Magarey; Frank H. Koch; Richard H. A. Baker; Susan P. Worner; Nadila N. Gomez Raboteaux; Daniel W. McKenney; Erhard J. Dobesberger; Denys Yemshanov; Paul J. De Barro; William D. Hutchinson; Glenn Fowler; Tom M. Kalaris; John. Pedlar

    2010-01-01

    Pest risk maps are powerful visual communication tools to describe where invasive alien species might arrive, establish, spread, or cause harmful impacts. These maps inform strategic and tactical pest management decisions, such as potential restrictions on international trade or the design of pest surveys and domestic quarantines. Diverse methods are available to...

  9. Research Report Non-invasive DNA-based species and sex ...

    Indian Academy of Sciences (India)

    shrushti modi

    Non-invasive DNA-based species and sex identification of Asiatic wild dog (Cuon alpinus) .... We did not find any cross-gender amplification with any of the reference or field-collected samples. Success rate for sex discrimination for all field-.

  10. Impacts of nonnative invasive species on US forests and recommendations for policy and management

    Science.gov (United States)

    W. Keith Moser; Edward L. Barnard; Ronald F. Billings; Susan J. Crocker; Andrew N. Gray; George G. Ice; Mee-Sook Kim; Richard Reid; Sue U. Rodman; William H. McWilliams

    2009-01-01

    The introduction of nonnative invasive species (NNIS) into the United States has had tremendous impacts on the nation's commercial and urban forest resources. Of principal concern are the effects of NNIS on forest composition, structure, function, productivity, and patterns of carbon sequestration. In 2006, the Society of American Foresters commissioned an ad hoc...

  11. An invasive mosquito species Aedes albopictus found in the Czech Republic, 2012

    Czech Academy of Sciences Publication Activity Database

    Šebesta, Oldřich; Rudolf, Ivo; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk

    2012-01-01

    Roč. 17, č. 43 (2012), s. 20301 ISSN 1560-7917 Institutional support: RVO:68081766 Keywords : invasive mosquito species * Aedes albopictus Subject RIV: EG - Zoology Impact factor: 5.491, year: 2012 http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20301

  12. Missing the Boat on Invasive Alien Species: A Review of Post-Secondary Curricula in Canada

    Science.gov (United States)

    Smith, Andrea L.; Bazely, Dawn R.; Yan, Norman D.

    2011-01-01

    Invasive alien species (IAS) cause major environmental and economic damage worldwide, and also threaten human food security and health. The impacts of IAS are expected to rise with continued globalization, land use modification, and climate change. Developing effective strategies to deal with IAS requires a collaborative, interdisciplinary…

  13. On the potential of plant species invasion influencing bio-geomorphologic landscape formation in salt marshes

    NARCIS (Netherlands)

    Schwarz, Christian; Ysebaert, Tom; Vandenbruwaene, Wouter; Temmerman, Stijn; Zhang, Li Quan; Herman, Peter M.J.

    2016-01-01

    Species invasions are known to change biotic and abiotic ecosystem characteristics such as community structure, cycling of materials and dynamics of rivers. However, their ability to alter interactions between biotic and abiotic ecosystem components, in particular bio-geomorphic feedbacks and the

  14. On the potential of plant species invasion influencing bio-geomorphologic landscape formation in salt marshes

    NARCIS (Netherlands)

    Schwarz, C.; Ysebaert, T.; Vandenbruwaene, W.; Temmerman, S.; Zhang, L.; Herman, P.

    2016-01-01

    Species invasions are known to change biotic and abiotic ecosystem characteristics such as community structure, cycling of materials and dynamics of rivers. However, their ability to alter interactions between biotic and abiotic ecosystem components, in particular bio-geomorphic feedbacks and the

  15. Working across cultures to protect Native American natural and cultural resources from invasive species in California

    Science.gov (United States)

    Janice M. Alexander; Susan J. Frankel; Nina Hapner; John L. Phillips; Virgil Dupuis

    2017-01-01

    Invasive species know no boundaries; they spread regardless of ownership, and actions by neighboring landowners can influence local and regional populations and impacts. Native Americans and mainstream Western society (representing the prevalent attitudes, values, and practices of US society) both depend on forests for food, fiber, and emotional well-being, but in...

  16. A new approach to horizon-scanning: identifying potentially invasive alien species and their introduction pathways

    NARCIS (Netherlands)

    Matthews, Jonathan; Beringen, Ruud; Creemers, Raymond; Hollander, Hans; van Kessel, Nils; van Kleef, Hein; de Koppel, Sander van; Lemaire, Adrienne J. J.; Ode, Baudewijn; Verbrugge, Laura N. H.; Hendriks, A. Jan; Schipper, Aafke M.; van der Velde, Gerard; Leuven, Rob S. E. W.

    Invasive alien species (IAS) are considered an important threat to global biodiversity due to major ecological impacts. In 2014, the European Union (EU) introduced a regulation (EU) No 1143/2014 on the prevention and management of the introduction and spread of IAS. The first risk prioritized list

  17. Prediction of Prosopis species invasion in Kenya using geographical information system techniques

    NARCIS (Netherlands)

    Muturi, G.M.; Mohren, G.M.J.; Kimani, J.N.

    2010-01-01

    Tree species from Prosopis genus were widely planted for rehabilitation of degraded drylands of Kenya. However, they have invaded riverine ecosystems where they cause negative socio-economic and ecological impacts. GIS was used to estimate the reverine area threatened by Prosopis invasion in Kenya.

  18. Maintenance of salt barrens inhibited landward invasion of Spartina species in salt marshes

    NARCIS (Netherlands)

    Qi, Man; Sun, Tao; Zhang, Heyue; Zhu, Meisha; Yang, Ying-Wei; Shao, Dongdong; Voinov, Alexey

    2017-01-01

    Spartina spp. (cordgrasses) often dominates intertidal mudflats and/or low marshes. The landward invasion of these species was typically thought to be restrained by low tidal inundation frequencies and interspecific competition. We noticed that the reported soil salinity levels in some salt marshes

  19. Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity.

    Science.gov (United States)

    Porté, Annabel J; Lamarque, Laurent J; Lortie, Christopher J; Michalet, Richard; Delzon, Sylvain

    2011-11-24

    To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread in European resource

  20. The aggressive invasion of exotic reptiles in Florida with a focus on prominent species: A review

    Directory of Open Access Journals (Sweden)

    Richard ENGEMAN, Elliott JACOBSON, Michael L. AVERY

    2011-10-01

    Full Text Available Florida, along with Hawaii, has among the two worst invasive species problems in the USA, and the state is especially susceptible to establishment by alien reptiles. Besides the large numbers of established non-native reptile species in Florida, many of these species present novel difficulties for management, or have other characteristics making effective management extremely challenging. Moreover, initiation of management action requires more than recognition by experts that a potentially harmful species has become established. It also requires the political will along with concomitant resources and appropriate personnel to develop effective methods and apply them. We review the situation in Florida, including assessment of risk for establishment, and we use a subset of prominent species to illustrate in more detail the array of invasive reptile species circumstances in Florida, including routes of introduction, impacts, and potential and implemented management actions. These examples not only highlight the severity of the invasive reptile problems in the state, but they also show the diversity in resolve and response towards them and the motivating factors [Current Zoology 57 (5: 599–612, 2011].

  1. Vulnerability of Rehabilitated Agricultural Production Systems to Invasion by Nontarget Plant Species

    Science.gov (United States)

    Baer, Sara G.; Engle, David M.; Knops, Johannes M. H.; Langeland, Kenneth A.; Maxwell, Bruce D.; Menalled, Fabian D.; Symstad, Amy J.

    2009-02-01

    Vast areas of arable land have been retired from crop production and “rehabilitated” to improved system states through landowner incentive programs in the United States (e.g., Conservation and Wetland Reserve Programs), as well as Europe (i.e., Agri-Environment Schemes). Our review of studies conducted on invasion of rehabilitated agricultural production systems by nontarget species elucidates several factors that may increase the vulnerability of these systems to invasion. These systems often exist in highly fragmented and agriculturally dominated landscapes, where propagule sources of target species for colonization may be limited, and are established under conditions where legacies of past disturbance persist and prevent target species from persisting. Furthermore, rehabilitation approaches often do not include or successfully attain all target species or historical ecological processes (e.g., hydrology, grazing, and/or fire cycles) key to resisting invasion. Uncertainty surrounds ways in which nontarget species may compromise long term goals of improving biodiversity and ecosystem services through rehabilitation efforts on former agricultural production lands. This review demonstrates that more studies are needed on the extent and ecological impacts of nontarget species as related to the goals of rehabilitation efforts to secure current and future environmental benefits arising from this widespread conservation practice.

  2. Interference competition between an invasive parakeet and native bird species at feeding sites.

    Science.gov (United States)

    Le Louarn, Marine; Couillens, Bertrand; Deschamps-Cottin, Magali; Clergeau, Philippe

    2016-01-01

    Interference competition has proved to be a factor of successful establishment of invasive species. This type of competition may have a stronger impact when native species have temporal niche overlap with the invasive species. The ring-necked parakeet Psittacula krameri has been successfully introduced in many countries and its interspecific agonistic behavior has already been reported. The purpose of this study is to analyze the territorial and preemptive interference competition between the ring-necked parakeet and native bird species in a recently colonized area. We used an empirical approach by recording video sequences in gardens equipped with bird feeders in winter. Our results showed that the ring-necked parakeet was the most frequent species at the feeders. Several native species showed temporal niche overlap with the ring-necked parakeet, the highest overlap being with the starling Sturnus vulgaris . The starling was also the species most impacted by interference competition with the parakeet. Our study suggests that, by being most frequently present at the feeders, by demonstrating the most agonistic behavior and by hindering access to food of the other species, the ring-necked parakeet is a superior competitor and may compete with native bird species.

  3. Comparative Ultrastructure and Carbohydrate Composition of Gastroliths from Astacidae, Cambaridae and Parastacidae Freshwater Crayfish (Crustacea, Decapoda

    Directory of Open Access Journals (Sweden)

    Gérard Alcaraz

    2012-12-01

    Full Text Available Crustaceans have to cyclically replace their rigid exoskeleton in order to grow. Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohydrate composition. This study was performed in a comparative perspective on crayfish species belonging to the infra-order Astacidea (Decapoda, Malacostraca: three species from the Astacoidea superfamily and one species from the Parastacoidea superfamily. We observed that all the gastroliths exhibit a similar dense network of protein-chitin fibers, from macro- to nanoscale, within which calcium is precipitated as amorphous calcium carbonate. Nevertheless, they are not very similar at the molecular level, notably as regards their carbohydrate composition. Besides glucosamine, the basic carbohydrate component of chitin, we evidenced the presence of other sugars, some of which are species-specific like rhamnose and galacturonic acid whereas xylose and mannose could be linked to proteoglycan components.

  4. Assessing distributions of two invasive species of contrasting habits in future climate.

    Science.gov (United States)

    Panda, Rajendra Mohan; Behera, Mukunda Dev; Roy, Partha Sarathi

    2018-05-01

    Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C. tora may demonstrate physiological tolerance to the mean diurnal temperature range and L. camara to the solar radiation. C. tora may invade central India, while L. camara may invade the Western Himalaya, parts of the Eastern Himalaya and the Western Ghats. The distribution ranges of both species could shift in the northern and north-eastern directions in India, owing to changes in moisture availability. The possible alterations in precipitation regimes could lead to water stress, which might have cascading effects on species invasion. L. camara might adapt to climate change better compared with C. tora. This comparative analysis of the future distributions of two invasive plants with contrasting habits demonstrates that temporal complementarity would prevail over the competition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Thermal ecological physiology of native and invasive frog species: do invaders perform better?

    Science.gov (United States)

    Cortes, Pablo A; Puschel, Hans; Acuña, Paz; Bartheld, José L; Bozinovic, Francisco

    2016-01-01

    Biological invasions are recognized as an important biotic component of global change that threatens the composition, structure and functioning of ecosystems, resulting in loss of biodiversity and displacement of native species. Although ecological characteristics facilitating the establishment and spread of non-native species are widely recognized, little is known about organismal attributes underlying invasion success. In this study, we tested the effect of thermal acclimation on thermal tolerance and locomotor performance in the invasive Xenopus laevis and the Chilean native Calyptocephalella gayi . In particular, the maximal righting performance (μ MAX ), optimal temperature ( T O ), lower (CT min ) and upper critical thermal limits (CT max ), thermal breadth ( T br ) and the area under the performance curve (AUC) were studied after 6 weeks acclimation to 10 and 20°C. We observed higher values of μ max and AUC in X. laevis in comparison to C. gayi . On the contrary, the invasive species showed lower values of CT min in comparison to the native one. In contrast, CT max , T O and T br showed no inter-specific differences. Moreover, we found that both species have the ability to acclimate their locomotor performance and lower thermal tolerance limit at low temperatures. Our results demonstrate that X. laevis is a better performer than C. gayi . Although there were differences in CT min , the invasive and native frogs did not differ in their thermal tolerance. Interestingly, in both species the lower and upper critical thermal limits are beyond the minimal and maximal temperatures encountered in nature during the coldest and hottest month, respectively. Overall, our findings suggest that both X. laevis and C. gayi would be resilient to climate warming expectations in Chile.

  6. Genetic networking of the Bemisia tabaci cryptic species complex reveals pattern of biological invasions.

    Directory of Open Access Journals (Sweden)

    Paul De Barro

    Full Text Available BACKGROUND: A challenge within the context of cryptic species is the delimitation of individual species within the complex. Statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. The results also enable us to explore the spread in taxa that have invaded globally. METHODOLOGY/PRINCIPAL FINDINGS: Using a 657 bp portion of mitochondrial cytochrome oxidase 1 from 352 unique haplotypes belonging to the Bemisia tabaci cryptic species complex, the analysis revealed 28 networks plus 7 unconnected individual haplotypes. Of the networks, 24 corresponded to the putative species identified using the rule set devised by Dinsdale et al. (2010. Only two species proposed in Dinsdale et al. (2010 departed substantially from the structure suggested by the analysis. The analysis of the two invasive members of the complex, Mediterranean (MED and Middle East - Asia Minor 1 (MEAM1, showed that in both cases only a small number of haplotypes represent the majority that have spread beyond the home range; one MEAM1 and three MED haplotypes account for >80% of the GenBank records. Israel is a possible source of the globally invasive MEAM1 whereas MED has two possible sources. The first is the eastern Mediterranean which has invaded only the USA, primarily Florida and to a lesser extent California. The second are western Mediterranean haplotypes that have spread to the USA, Asia and South America. The structure for MED supports two home range distributions, a Sub-Saharan range and a Mediterranean range. The MEAM1 network supports the Middle East - Asia Minor region. CONCLUSION/SIGNIFICANCE: The network analyses show a high level of congruence with the species identified in a previous phylogenetic analysis. The analysis of the two globally invasive members of the complex support the view that global invasion often involve very small portions of

  7. What does "local" firewood buy you? Managing the risk of invasive species introduction.

    Science.gov (United States)

    Tobin, Patrick C; Diss-Torrance, Andrea; Blackburn, Laura M; Brown, Brian D

    2010-10-01

    Firewood can serve as a vector in the transport of non-native species, including wood-boring insects that feed within the wood and thus can be transported accidentally. Governments have enacted limitations on the movement of firewood in an effort to limit the anthropogenic movement of non-native species through, for example, recreational camping. Although the movement of invasive species through firewood is a documented invasion pathway, it is not trivial for governments to determine a "safe" allowable distance for moving firewood. We were motivated by this challenge and developed a theoretical simulation to determine the campgrounds that could be potentially exposed to infested firewood based upon the hypothetical distribution of an invasive species and the allowable distance for moving firewood. We extend this concept to the known distributions of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) and Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) Coleoptera: Cerambycidae). We illustrate, based upon theoretical and empirical observations, that as the distribution of an invasive species increases, more rigid constraints on the movement of firewood would be required relative to those species that are distributed over a smaller scale. Also, on the level of management within a state, smaller states have far less margin for error than larger ones, as even extremely rigid restrictions on the movement of firewood could have little management effect unless the infested area is spatially limited. These results collectively suggest the potential for a dynamic management strategy that adjusts allowable distances for firewood movement based upon the distribution of the non-native species.

  8. Does the order of invasive species removal matter? The case of the eagle and the pig.

    Directory of Open Access Journals (Sweden)

    Paul W Collins

    2009-09-01

    Full Text Available Invasive species are recognized as a primary driver of native species endangerment and their removal is often a key component of a conservation strategy. Removing invasive species is not always a straightforward task, however, especially when they interact with other species in complex ways to negatively influence native species. Because unintended consequences may arise if all invasive species cannot be removed simultaneously, the order of their removal is of paramount importance to ecological restoration. In the mid-1990s, three subspecies of the island fox Urocyon littoralis were driven to near extinction on the northern California Channel Islands owing to heightened predation by golden eagles Aquila chrysaetos. Eagles were lured to the islands by an abundant supply of feral pigs Sus scrofa and through the process of apparent competition pigs indirectly facilitated the decline in foxes. As a consequence, both pigs and eagles had to be removed to recover the critically endangered fox. Complete removal of pigs was problematic: removing pigs first could force eagles to concentrate on the remaining foxes, increasing their probability of extinction. Removing eagles first was difficult: eagles are not easily captured and lethal removal was politically distasteful.Using prey remains collected from eagle nests both before and after the eradication of pigs, we show that one pair of eagles that eluded capture did indeed focus more on foxes. These results support the premise that if the threat of eagle predation had not been mitigated prior to pig removal, fox extinction would have been a more likely outcome.If complete eradication of all interacting invasive species is not possible, the order in which they are removed requires careful consideration. If overlooked, unexpected consequences may result that could impede restoration.

  9. Does the order of invasive species removal matter? The case of the eagle and the pig.

    Science.gov (United States)

    Collins, Paul W; Latta, Brian C; Roemer, Gary W

    2009-09-14

    Invasive species are recognized as a primary driver of native species endangerment and their removal is often a key component of a conservation strategy. Removing invasive species is not always a straightforward task, however, especially when they interact with other species in complex ways to negatively influence native species. Because unintended consequences may arise if all invasive species cannot be removed simultaneously, the order of their removal is of paramount importance to ecological restoration. In the mid-1990s, three subspecies of the island fox Urocyon littoralis were driven to near extinction on the northern California Channel Islands owing to heightened predation by golden eagles Aquila chrysaetos. Eagles were lured to the islands by an abundant supply of feral pigs Sus scrofa and through the process of apparent competition pigs indirectly facilitated the decline in foxes. As a consequence, both pigs and eagles had to be removed to recover the critically endangered fox. Complete removal of pigs was problematic: removing pigs first could force eagles to concentrate on the remaining foxes, increasing their probability of extinction. Removing eagles first was difficult: eagles are not easily captured and lethal removal was politically distasteful. Using prey remains collected from eagle nests both before and after the eradication of pigs, we show that one pair of eagles that eluded capture did indeed focus more on foxes. These results support the premise that if the threat of eagle predation had not been mitigated prior to pig removal, fox extinction would have been a more likely outcome. If complete eradication of all interacting invasive species is not possible, the order in which they are removed requires careful consideration. If overlooked, unexpected consequences may result that could impede restoration.

  10. Does temperature-mediated reproductive success drive the direction of species displacement in two invasive species of leafminer fly?

    Directory of Open Access Journals (Sweden)

    Haihong Wang

    Full Text Available Liriomyza sativae and L. trifolii (Diptera: Agromyzidae are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C. L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0 for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement

  11. Multistate models of bigheaded carps in the Illinois River reveal spatial dynamics of invasive species

    Science.gov (United States)

    Coulter, Alison A.; Brey, Marybeth; Lubejko, Matthew; Kallis, Jahn L.; Coulter, David P.; Glover, David C.; Whitledge, Gregory W.; Garvey, James E.

    2018-01-01

    Knowledge of the spatial distributions and dispersal characteristics of invasive species is necessary for managing the spread of highly mobile species, such as invasive bigheaded carps (Bighead Carp [Hypophthalmichthys nobilis] and Silver Carp [H. molitrix]). Management of invasive bigheaded carps in the Illinois River has focused on using human-made barriers and harvest to limit dispersal towards the Laurentian Great Lakes. Acoustic telemetry data were used to parameterize multistate models to examine the spatial dynamics of bigheaded carps in the Illinois River to (1) evaluate the effects of existing dams on movement, (2) identify how individuals distribute among pools, and (3) gauge the effects of reductions in movement towards the invasion front. Multistate models estimated that movement was generally less likely among upper river pools (Starved Rock, Marseilles, and Dresden Island) than the lower river (La Grange and Peoria) which matched the pattern of gated versus wicket style dams. Simulations using estimated movement probabilities indicated that Bighead Carp accumulate in La Grange Pool while Silver Carp accumulate in Alton Pool. Fewer Bighead Carp reached the upper river compared to Silver Carp during simulations. Reducing upstream movement probabilities (e.g., reduced propagule pressure) by ≥ 75% into any of the upper river pools could reduce upper river abundance with similar results regardless of location. Given bigheaded carp reproduction in the upper Illinois River is presently limited, reduced movement towards the invasion front coupled with removal of individuals reaching these areas could limit potential future dispersal towards the Great Lakes.

  12. Rapid evolution mitigates the ecological consequences of an invasive species (Bythotrephes longimanus) in lakes in Wisconsin.

    Science.gov (United States)

    Gillis, Michael K; Walsh, Matthew R

    2017-07-12

    Invasive species have extensive negative consequences for biodiversity and ecosystem health. Novel species also drive contemporary evolution in many native populations, which could mitigate or amplify their impacts on ecosystems. The predatory zooplankton Bythotrephes longimanus invaded lakes in Wisconsin, USA, in 2009. This invasion caused precipitous declines in zooplankton prey ( Daphnia pulicaria ), with cascading impacts on ecosystem services (water clarity). Here, we tested the link between Bythotrephes invasion, evolution in Daphnia and post-invasion ecological dynamics using 15 years of long-term data in conjunction with comparative experiments. Invasion by Bythotrephes is associated with rapid increases in the body size of Daphnia Laboratory experiments revealed that such shifts have a genetic component; third-generation laboratory-reared Daphnia from 'invaded' lakes are significantly larger and exhibit greater reproductive effort than individuals from 'uninvaded' lakes. This trajectory of evolution should accelerate Daphnia population growth and enhance population persistence. We tested this prediction by comparing analyses of long-term data with laboratory-based simulations, and show that rapid evolution in Daphnia is associated with increased population growth in invaded lakes. © 2017 The Authors.

  13. Predicting plant invasions under climate change: are species distribution models validated by field trials?

    Science.gov (United States)

    Sheppard, Christine S; Burns, Bruce R; Stanley, Margaret C

    2014-09-01

    Climate change may facilitate alien species invasion into new areas, particularly for species from warm native ranges introduced into areas currently marginal for temperature. Although conclusions from modelling approaches and experimental studies are generally similar, combining the two approaches has rarely occurred. The aim of this study was to validate species distribution models by conducting field trials in sites of differing suitability as predicted by the models, thus increasing confidence in their ability to assess invasion risk. Three recently naturalized alien plants in New Zealand were used as study species (Archontophoenix cunninghamiana, Psidium guajava and Schefflera actinophylla): they originate from warm native ranges, are woody bird-dispersed species and of concern as potential weeds. Seedlings were grown in six sites across the country, differing both in climate and suitability (as predicted by the species distribution models). Seedling growth and survival were recorded over two summers and one or two winter seasons, and temperature and precipitation were monitored hourly at each site. Additionally, alien seedling performances were compared to those of closely related native species (Rhopalostylis sapida, Lophomyrtus bullata and Schefflera digitata). Furthermore, half of the seedlings were sprayed with pesticide, to investigate whether enemy release may influence performance. The results showed large differences in growth and survival of the alien species among the six sites. In the more suitable sites, performance was frequently higher compared to the native species. Leaf damage from invertebrate herbivory was low for both alien and native seedlings, with little evidence that the alien species should have an advantage over the native species because of enemy release. Correlations between performance in the field and predicted suitability of species distribution models were generally high. The projected increase in minimum temperature and reduced

  14. Integrating Remote Sensing with Species Distribution Models; Mapping Tamarisk Invasions Using the Software for Assisted Habitat Modeling (SAHM)

    OpenAIRE

    West, Amanda M.; Evangelista, Paul H.; Jarnevich, Catherine S.; Young, Nicholas E.; Stohlgren, Thomas J.; Talbert, Colin; Talbert, Marian; Morisette, Jeffrey; Anderson, Ryan

    2016-01-01

    Early detection of invasive plant species is vital for the management of natural resources and protection of ecosystem processes. The use of satellite remote sensing for mapping the distribution of invasive plants is becoming more common, however conventional imaging software and classification methods have been shown to be unreliable. In this study, we test and evaluate the use of five species distribution model techniques fit with satellite remote sensing data to map invasive tamarisk (Tama...

  15. Potential establishment of alien-invasive forest insect species in the United States: where and how many?

    Science.gov (United States)

    Frank H. Koch; Denys Yemshanov; Manuel Colunga-Garcia; Roger D. Magarey; William D. Smith

    2011-01-01

    International trade is widely acknowledged as a conduit for movement of invasive species, but few studies have directly quantified the invasion risk confronting individual locations of interest. This study presents estimates of the likelihood of successful entry for alien forest insect species at more than 3,000 urban areas in the contiguous United States (US). To...

  16. Leaf litter traits of invasive alien species slow down decomposition compared to Spanish natives: a broad phylogenetic comparison.

    NARCIS (Netherlands)

    Godoy, O.; Castro Diez, P.; van Logtestijn, R.S.P; Cornelissen, J.H.C.; Valladares, F.

    2010-01-01

    Leaf traits related to the performance of invasive alien species can influence nutrient cycling through litter decomposition. However, there is no consensus yet about whether there are consistent differences in functional leaf traits between invasive and native species that also manifest themselves

  17. An assessment of invasive plant species monitored by the Northern Research Station Forest Inventory and Analysis Program, 2005 through 2010

    Science.gov (United States)

    Cassandra M. Kurtz

    2013-01-01

    Invasive plant species are a worldwide concern due to the high ecological and economic costs associated with their presence. This document describes the plant characteristics and regional distribution of the 50 invasive plant species monitored from 2005 through 2010 on forested Phase 2 (P2) Forest Inventory and Analysis (FIA) plots in the 24 states of the Northern...

  18. Insecticide-mediated apparent displacement between two invasive species of leafminer fly.

    Directory of Open Access Journals (Sweden)

    Yulin Gao

    Full Text Available BACKGROUND: Closely related invasive species may often displace one another, but it is often difficult to determine mechanisms because of the historical nature of these events. The leafmining flies Liriomyza sativae and Liriomyza trifolii have become serious invasive agricultural pests throughout the world. Where both species have invaded the same region, one predominates over the other. Although L. sativae invaded Hainan Island of China first, it recently has been displaced by the newly invasive L. trifolii. We hypothesized that differential susceptibilities to insecticides could be causing this demographic shift. METHODOLOGY/PRINCIPAL FINDINGS: Avermectin and cyromazine are the most commonly used insecticides to manage leafminers, with laboratory bioassays demonstrating that L. trifolii is significantly less susceptible to these key insecticides than is L. sativae. In trials where similar numbers of larvae of both species infested plants, which subsequently were treated with the insecticides, the eclosing adults were predominately L. trifolii, yet similar numbers of adults of both species eclosed from control plants. The species composition was then surveyed in two regions where L. trifolii has just begun to invade and both species are still common. In field trials, both species occurred in similar proportions before insecticide treatments began. Following applications of avermectin and cyromazine, almost all eclosing adults were L. trifolii in those treatment plots. In control plots, similar numbers of adults of the two species eclosed, lending further credence to the hypothesis that differential insecticide susceptibilities could be driving the ongoing displacement of L. sativae by L. trifolii. CONCLUSIONS/SIGNIFICANCE: Our results show that differential insecticide susceptibility can lead to rapid shifts in the demographics of pest complexes. Thus, successful pest management requires the identification of pest species to understand the

  19. The use of environmental DNA in invasive species surveillance of the Great Lakes commercial bait trade.

    Science.gov (United States)

    Nathan, Lucas R; Jerde, Christopher L; Budny, Michelle L; Mahon, Andrew R

    2015-04-01

    Over 180 non-native species have been introduced in the Laurentian Great Lakes region, many posing threats to native species and ecosystem functioning. One potential pathway for introductions is the commercial bait trade; unknowing or unconcerned anglers commonly release unused bait into aquatic systems. Previous surveillance efforts of this pathway relied on visual inspection of bait stocks in retail shops, which can be time and cost prohibitive and requires a trained individual that can rapidly and accurately identify cryptic species. Environmental DNA (eDNA) surveillance, a molecular tool that has been used for surveillance in aquatic environments, can be used to efficiently detect species at low abundances. We collected and analyzed 576 eDNA samples from 525 retail bait shops throughout the Laurentian Great Lake states. We used eDNA techniques to screen samples for multiple aquatic invasive species (AIS) that could be transported in the bait trade, including bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix), round goby (Neogobius melanostomus), tubenose goby (Proterorhinus marmoratus), Eurasian rudd (Scardinius erythrophthalmus), and goldfish (Carassius auratus). Twenty-seven samples were positive for at least one target species (4.7% of samples), and all target species were found at least once, except bighead carp. Despite current regulations, the bait trade remains a potential pathway for invasive species introductions in the Great Lakes region. Alterations to existing management strategies regarding the collection, transportation, and use of live bait are warranted, including new and updated regulations, to prevent future introductions of invasive species in the Great Lakes via the bait trade. © 2014 Society for Conservation Biology.

  20. Optimal control applied to native-invasive species competition via a PDE model

    Directory of Open Access Journals (Sweden)

    Wandi Ding

    2012-12-01

    Full Text Available We consider an optimal control problem of a system of parabolic partial differential equations modelling the competition between an invasive and a native species. The motivating example is cottonwood-salt cedar competition, where the effect of disturbance in the system (such as flooding is taken to be a control variable. Flooding being detrimental at low and high levels, and advantageous at medium levels led us to consider the quadratic growth function of the control. The objective is to maximize the native species and minimize the invasive species while minimizing the cost of implementing the control. An existence result for an optimal control is given. Numerical examples are presented to illustrate the results.

  1. Invasive hybridization in a threatened species is accelerated by climate change

    Science.gov (United States)

    Muhlfeld, Clint C.; Kovach, Ryan P.; Jones, Leslie A.; Al-Chokhachy, Robert; Boyer, Matthew C.; Leary, Robb F.; Lowe, Winsor H.; Luikart, Gordon; Allendorf, Fred W.

    2014-07-01

    Climate change will decrease worldwide biodiversity through a number of potential pathways, including invasive hybridization (cross-breeding between invasive and native species). How climate warming influences the spread of hybridization and loss of native genomes poses difficult ecological and evolutionary questions with little empirical information to guide conservation management decisions. Here we combine long-term genetic monitoring data with high-resolution climate and stream temperature predictions to evaluate how recent climate warming has influenced the spatio-temporal spread of human-mediated hybridization between threatened native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and non-native rainbow trout (Oncorhynchus mykiss), the world's most widely introduced invasive fish. Despite widespread release of millions of rainbow trout over the past century within the Flathead River system, a large relatively pristine watershed in western North America, historical samples revealed that hybridization was prevalent only in one (source) population. During a subsequent 30-year period of accelerated warming, hybridization spread rapidly and was strongly linked to interactions between climatic drivers--precipitation and temperature--and distance to the source population. Specifically, decreases in spring precipitation and increases in summer stream temperature probably promoted upstream expansion of hybridization throughout the system. This study shows that rapid climate warming can exacerbate interactions between native and non-native species through invasive hybridization, which could spell genomic extinction for many species.

  2. Invasive hybridization in a threatened species is accelerated by climate change

    Science.gov (United States)

    Muhlfeld, Clint C.; Kovach, Ryan P.; Jones, Leslie A.; Al-Chokhachy, Robert K.; Boyer, Matthew C.; Leary, Robb F.; Lowe, Winsor H.; Luikart, Gordon; Allendorf, Fred W.

    2014-01-01

    Climate change will decrease worldwide biodiversity through a number of potential pathways, including invasive hybridization (cross-breeding between invasive and native species). How climate warming influences the spread of hybridization and loss of native genomes poses difficult ecological and evolutionary questions with little empirical information to guide conservation management decisions. Here we combine long-term genetic monitoring data with high-resolution climate and stream temperature predictions to evaluate how recent climate warming has influenced the spatio-temporal spread of human-mediated hybridization between threatened native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and non-native rainbow trout (Oncorhynchus mykiss), the world’s most widely introduced invasive fish. Despite widespread release of millions of rainbow trout over the past century within the Flathead River system, a large relatively pristine watershed in western North America, historical samples revealed that hybridization was prevalent only in one (source) population. During a subsequent 30-year period of accelerated warming, hybridization spread rapidly and was strongly linked to interactions between climatic drivers—precipitation and temperature—and distance to the source population. Specifically, decreases in spring precipitation and increases in summer stream temperature probably promoted upstream expansion of hybridization throughout the system. This study shows that rapid climate warming can exacerbate interactions between native and non-native species through invasive hybridization, which could spell genomic extinction for many species.

  3. Management of invasive plant species in Nigeria through economic exploitation: lessons from other countries

    Directory of Open Access Journals (Sweden)

    Folaranmi Dapo Babalola

    2012-12-01

    Full Text Available Invasive alien species, once they made entry into a region or country, often become difficult to eradicate and it appears that they have cometo stay. Worse still, their adverse effects on the native biodiversity are enormous and they are considered ecologically harmful. Agriculturaland economic losses to invasive species are comparatively high. Mechanical control is expensive and difficult in some terrains; chemicalcontrol is also expensive, requires constant application and has its environmental implications, while biological control is mirred with mixedfailures and successes. This paper reviewed that economic exploitation of some notorious invasive species in other countries – such asSudan, Ethiopia, India, Senegal, Mali and the Gambia – and how this had helped reduce the spread of these invasives and at the same time,became source of income to the poor people. It is believed that adopting this concept in Nigeria will create incentives for harvesting invasivespecies with more commitment, while it is an indirect way of controlling them. Furthermore, harvesting could be labour intensive, thuscreating jobs for people, while it provides additional means of income for rural people, which is a key adaptation strategy for climate change.

  4. Assessment of the invasive status of newly recorded cactus species in the central Tugela River basin

    Directory of Open Access Journals (Sweden)

    Michael D. Cheek

    2015-12-01

    Full Text Available Background: Current distribution information on cacti in the Tugela River basin in KwaZulu-Natal, South Africa, is scant. Accordingly, surveys in this region substantially improve our understanding of regional invasions by this succulent group. The identification of new or extended invasions requires (reassessments of their invasion status and consideration of possible management interventions. Objectives: To identify and collect cacti either not previously recorded or poorly known in the central Tugela River basin, and to assess their invasion status. Method: A 40 km section of tertiary road was travelled through the topocadastral square 2830 CC, from the R74 main road northward across the Bloukrans River towards the Tugela River. Herbarium specimens were collected to vouch for new instances of naturalisation of cacti, the colony sizes of which were estimated and invasion stages determined. An applicable weed risk assessment model was used to determine the threat status of one cactus species not previously evaluated for South Africa. Based on the South African Plant Invaders Atlas database records and field observations, management recommendations were suggested for six cacti species. Results: The first naturalised population of Opuntia microdasys in KwaZulu-Natal was detected, as was the first confirmed South African record of Echinopsis oxygona. Four populations of Peniocereus serpentinus were also found, ranging in size from several square metres to 0.4 ha. Echinopsis oxygona generated a score that falls into the reject category of the risk assessment model used. Conclusion: It is recommended that E. oxygona be added to the Species Under Surveillance for Possible Eradication or Containment Targeting list to investigate whether this species requires formal legal listing and the development of a specific eradication plan. Immediate action from local authorities is recommended for the manual removal of P. serpentinus and O. microdasys

  5. Analysis of a native whitefly transcriptome and its sequence divergence with two invasive whitefly species

    Directory of Open Access Journals (Sweden)

    Wang Xiao-Wei

    2012-10-01

    Full Text Available Abstract Background Genomic divergence between invasive and native species may provide insight into the molecular basis underlying specific characteristics that drive the invasion and displacement of closely related species. In this study, we sequenced the transcriptome of an indigenous species, Asia II 3, of the Bemisia tabaci complex and compared its genetic divergence with the transcriptomes of two invasive whiteflies species, Middle East Asia Minor 1 (MEAM1 and Mediterranean (MED, respectively. Results More than 16 million reads of 74 base pairs in length were obtained for the Asia II 3 species using the Illumina sequencing platform. These reads were assembled into 52,535 distinct sequences (mean size: 466 bp and 16,596 sequences were annotated with an E-value above 10-5. Protein family comparisons revealed obvious diversification among the transcriptomes of these species suggesting species-specific adaptations during whitefly evolution. On the contrary, substantial conservation of the whitefly transcriptomes was also evident, despite their differences. The overall divergence of coding sequences between the orthologous gene pairs of Asia II 3 and MEAM1 is 1.73%, which is comparable to the average divergence of Asia II 3 and MED transcriptomes (1.84% and much higher than that of MEAM1 and MED (0.83%. This is consistent with the previous phylogenetic analyses and crossing experiments suggesting these are distinct species. We also identified hundreds of highly diverged genes and compiled sequence identify data into gene functional groups and found the most divergent gene classes are Cytochrome P450, Glutathione metabolism and Oxidative phosphorylation. These results strongly suggest that the divergence of genes related to metabolism might be the driving force of the MEAM1 and Asia II 3 differentiation. We also analyzed single nucleotide polymorphisms within the orthologous gene pairs of indigenous and invasive whiteflies which are helpful for

  6. Identification of invasive and expansive plant species based on airborne hyperspectral and ALS data

    Science.gov (United States)

    Szporak-Wasilewska, Sylwia; Kuc, Gabriela; Jóźwiak, Jacek; Demarchi, Luca; Chormański, Jarosław; Marcinkowska-Ochtyra, Adriana; Ochtyra, Adrian; Jarocińska, Anna; Sabat, Anita; Zagajewski, Bogdan; Tokarska-Guzik, Barbara; Bzdęga, Katarzyna; Pasierbiński, Andrzej; Fojcik, Barbara; Jędrzejczyk-Korycińska, Monika; Kopeć, Dominik; Wylazłowska, Justyna; Woziwoda, Beata; Michalska-Hejduk, Dorota; Halladin-Dąbrowska, Anna

    2017-04-01

    The aim of Natura 2000 network is to ensure the long term survival of most valuable and threatened species and habitats in Europe. The encroachment of invasive alien and expansive native plant species is among the most essential threat that can cause significant damage to protected habitats and their biodiversity. The phenomenon requires comprehensive and efficient repeatable solutions that can be applied to various areas in order to assess the impact on habitats. The aim of this study is to investigate of the issue of invasive and expansive plant species as they affect protected areas at a larger scale of Natura 2000 network in Poland. In order to determine the scale of the problem we have been developing methods of identification of invasive and expansive species and then detecting their occurrence and mapping their distribution in selected protected areas within Natura 2000 network using airborne hyperspectral and airborne laser scanning data. The aerial platform used consists of hyperspectral HySpex scanner (451 bands in VNIR and SWIR), Airborne Laser Scanner (FWF) Riegl Lite Mapper and RGB camera. It allowed to obtain simultaneous 1 meter resolution hyperspectral image, 0.1 m resolution orthophotomaps and point cloud data acquired with 7 points/m2. Airborne images were acquired three times per year during growing season to account for plant seasonal change (in May/June, July/August and September/October 2016). The hyperspectral images were radiometrically, geometrically and atmospherically corrected. Atmospheric correction was performed and validated using ASD FieldSpec 4 measurements. ALS point cloud data were used to generate several different topographic, vegetation and intensity products with 1 m spatial resolution. Acquired data (both hyperspectral and ALS) were used to test different classification methods including Mixture Tuned Matched Filtering (MTMF), Spectral Angle Mapper (SAM), Random Forest (RF), Support Vector Machines (SVM), among others

  7. Antibacterial properties of extracts of Solidago canadensis and their potential use as dietary supplements in red swamp crayfish (Procambarus clarkii

    Directory of Open Access Journals (Sweden)

    Manhong YE,Lei ZHANG,Jiaqi GE,Haifeng SUN,Jingjing NI,Shengmei YANG,Wanhong WEI

    2015-12-01

    Full Text Available Canadian goldenrod (Solidago canadensis is one of the most destructive invasive weeds in South-eastern China. To evaluate its potential application as dietary supplement in red swamp crayfish (Procambarus clarkii, the antibacterial properties of aqueous and ethanol extracts of this plant against three major pathogenic bacteria in crayfish aquaculture were examined. Inhibition zone tests and determination of minimum inhibitory concentration revealed that the extracts had lower antibacterial activity than extracts from two traditional medicinal plants that possess antibacterial properties, garlic (Allium sativum and cortex phellodendri (Phellodendron chinense. However, they did exhibit greater antibacterial effects than extracts from another widely used medicinal plant, Sophora flavescens, and an aquatic weed, Alternanthera philoxeroides. Aqueous extracts of Canadian goldenrod gave greater inhibition than the ethanol extracts. Crayfish fed a diet with 2% these aqueous extracts exhibited significantly higher enzyme activity of alkaline phosphatase, catalase and phenoloxidase (P<0.05. Based on the results of this study, we conclude that aqueous extracts of Canadian goldenrod are highly promising for the development of new dietary supplement for use in crayfish aquaculture.

  8. Modelling Favourability for Invasive Species Encroachment to Identify Areas of Native Species Vulnerability

    OpenAIRE

    Romero, David; Báez, José C.; Ferri-Yáñez, Francisco; Bellido, Jesús J.; Real, Raimundo

    2014-01-01

    We assessed the vulnerability of the native Mediterranean pond turtle to encroachment by the invasive red-eared slider in southern Spain. We first obtained an ecogeographical favourability model for the Mediterranean pond turtle. We then modelled the presence/absence of the red-eared slider in the Mediterranean pond turtle range and obtained an encroachment favourability model. We also obtained a favourability model for the red-eared slider using the ecogeographical favourability for the Medi...

  9. INVASIVE PLANTS IN MOUNTAINOUS REMNANT FOREST: RECOMMENDATION FOR CHOOSING BEST DECISION FOR INVASIVE SPECIES MANAGEMENT OF Cestrum aurantiacum Lindl.

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2012-01-01

    Full Text Available Cestrum aurantiacum Lindl. is an exotic species found in native remnant forest of GPNP which is located inside the Cibodas Botanic Garden (CBG. Risk assessment is an important tool to choose best decision for invasive plant management.  Risk assessment analysis on C. aurantiacum in Cibodas Botanic Garden was conducted using Multi Criteria Decision Analysis (MCDA method.  Analytical Hierarchy Process (AHP used in the valuation process. Three sub-criteria used: minimizing the ecological impact, minimizing the management cost, and maximizing the public acceptance. Five management alternatives were used: do nothing (DN, eradication (E, containment (C, bio-control (BC and harvesting (H. Harvesting (H recommended as the best management decision for C. aurantiacumin at CBG remnant forest. This harvesting decision is not only creating environment/ ecosystem remediation but also as sources of fund in the management activity of the area.

  10. Temperature-dependent performance of competitive native and alien invasive plant species

    Science.gov (United States)

    Song, Uhram

    2017-10-01

    To assess the likely impacts of environmental change, the responses of two well-known invasive plant species, native Pueraria lobata and alien Humulus japonicus, to differences in growth temperature were studied in South Korea. Habitat preferences, physiological responses such as photosynthetic rates and chlorophyll contents, growth rates, and nutrient contents were quantified for each species. A competition experiment was conducted to evaluate the temperature preferences of the two species. All results indicated that the alien species H. japonicus can take advantage of elevated temperatures (35 °C) to enhance its competitive advantage against the native species P. lobata. While H. japonicus took advantage of elevated temperatures and preferred high-temperature areas, P. lobata showed reduced performance and dominance in high-temperature areas. Therefore, in future, due to global warming and urbanization, there are possibilities that H. japonicus takes advantage of elevated temperature against P. lobata that could lead to increased H. japonicus coverage over time. Therefore, consistent monitoring of both species especially where P. lobata is dominated are required because both species are found in every continents in the world. Controlling P. lobata requires thorough inspection of H. japonicus presence of the habitat in advance to prevent post P. lobata management invasion of H. japonicus.

  11. Invasive species and habitat degradation in Iberian streams: an analysis of their role in freshwater fish diversity loss.

    Science.gov (United States)

    Hermoso, Virgilio; Clavero, Miguel; Blanco-Garrido, Francisco; Prenda, José

    2011-01-01

    Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions.

  12. Effects of an invasive plant species, celastrus orbiculatus, on soil composition and processes

    Science.gov (United States)

    Leicht-Young, S. A.; O'Donnell, H.; Latimer, A.M.; Silander, J.A.

    2009-01-01

    Celastrus orbiculatus is a non-native, invasive liana that was introduced to the United States in the 1860s and has spread rapidly throughout the Northeast Several attributes contribute to the invasiveness of C. orbiculatus, including tolerance to a wide range of light levels and habitat types. We compared soil characteristics in seven sets of adjacent, paired plots, spanning a range of habitats and soil types, with and without C. orbiculatus. The paired plots were similar other than the presence or absence of Celastrus. Plots with C. orbiculatus had significantly higher soil pH, potassium, calcium and magnesium levels. Furthermore, nitrogen mineralization and litter decomposition rates were higher in plots with C. orbiculatus. Phosphorus levels were not significantly different between the paired plots. The results of this study contribute to the growing body of research of the effects of invasive species on ecosystem processes.

  13. Managing conflict-generating invasive species in South Africa: Challenges and trade-offs

    Directory of Open Access Journals (Sweden)

    Tsungai Zengeya

    2017-03-01

    Full Text Available Background: This paper reviewed the benefits and negative impacts of alien species that are currently listed in the Alien and Invasive Species Regulations of the National Environmental Management: Biodiversity Act (Act no 10 of 2004 and certain alien species that are not yet listed in the regulations for which conflicts of interest complicate management. Objectives: Specifically, it identified conflict-generating species, evaluated the causes and driving forces of these conflicts and assessed how the conflicts have affected management. Method: A simple scoring system was used to classify the alien species according to their relative degree of benefits and negative impacts. Conflict-generating species were then identified and further evaluated using an integrated cognitive hierarchy theory and risk perception framework to identify the value systems (intrinsic and economic and risk perceptions associated with each conflict. Results: A total of 552 alien species were assessed. Most of the species were classified as inconsequential (55% or destructive (29%. Beneficial (10% and conflict-generating (6% species made a minor contribution. The majority (46% of the conflict cases were associated with more than one value system or both values and risk perception. The other conflicts cases were based on intrinsic (40% and utilitarian (14% value systems. Conclusions: Conflicts based on value and risk perceptions are inherently difficult to resolve because authorities need to balance the needs of different stakeholders while meeting the mandate of conserving the environment, ecosystem services and human well-being. This paper uses the identified conflict-generating species to highlight the challenges and trade-offs of managing invasive species in South Africa.

  14. Genetic diversity in three invasive clonal aquatic species in New Zealand

    Directory of Open Access Journals (Sweden)

    Sorrell Brian K

    2010-06-01

    Full Text Available Abstract Background Elodea canadensis, Egeria densa and Lagarosiphon major are dioecious clonal species which are invasive in New Zealand and other regions. Unlike many other invasive species, the genetic variation in New Zealand is very limited. Clonal reproduction is often considered an evolutionary dead end, even though a certain amount of genetic divergence may arise due to somatic mutations. The successful growth and establishment of invasive clonal species may be explained not by adaptability but by pre-existing ecological traits that prove advantageous in the new environment. We studied the genetic diversity and population structure in the North Island of New Zealand using AFLPs and related the findings to the number of introductions and the evolution that has occurred in the introduced area. Results Low levels of genetic diversity were found in all three species and appeared to be due to highly homogeneous founding gene pools. Elodea canadensis was introduced in 1868, and its populations showed more genetic structure than those of the more recently introduced of E. densa (1946 and L. major (1950. Elodea canadensis and L. major, however, had similar phylogeographic patterns, in spite of the difference in time since introduction. Conclusions The presence of a certain level of geographically correlated genetic structure in the absence of sexual reproduction, and in spite of random human dispersal of vegetative propagules, can be reasonably attributed to post-dispersal somatic mutations. Direct evidence of such evolutionary events is, however, still insufficient.

  15. Genetic diversity in three invasive clonal aquatic species in New Zealand

    Science.gov (United States)

    2010-01-01

    Background Elodea canadensis, Egeria densa and Lagarosiphon major are dioecious clonal species which are invasive in New Zealand and other regions. Unlike many other invasive species, the genetic variation in New Zealand is very limited. Clonal reproduction is often considered an evolutionary dead end, even though a certain amount of genetic divergence may arise due to somatic mutations. The successful growth and establishment of invasive clonal species may be explained not by adaptability but by pre-existing ecological traits that prove advantageous in the new environment. We studied the genetic diversity and population structure in the North Island of New Zealand using AFLPs and related the findings to the number of introductions and the evolution that has occurred in the introduced area. Results Low levels of genetic diversity were found in all three species and appeared to be due to highly homogeneous founding gene pools. Elodea canadensis was introduced in 1868, and its populations showed more genetic structure than those of the more recently introduced of E. densa (1946) and L. major (1950). Elodea canadensis and L. major, however, had similar phylogeographic patterns, in spite of the difference in time since introduction. Conclusions The presence of a certain level of geographically correlated genetic structure in the absence of sexual reproduction, and in spite of random human dispersal of vegetative propagules, can be reasonably attributed to post-dispersal somatic mutations. Direct evidence of such evolutionary events is, however, still insufficient. PMID:20565861

  16. Alkaloid concentration of the invasive plant species Ulex europaeus in relation to geographic origin and herbivory

    Science.gov (United States)

    Hornoy, Benjamin; Atlan, Anne; Tarayre, Michèle; Dugravot, Sébastien; Wink, Michael

    2012-11-01

    In the study of plant defense evolution, invasive plant species can be very insightful because they are often introduced without their enemies, and traits linked to defense can be released from selective pressures and evolve. Further, studying plant defense evolution in invasive species is important for biological control and use of these species. In this study, we investigated the evolution of the defensive chemicals quinolizidine alkaloids (QAs) in the invasive species gorse, Ulex europaeus. Using a common garden experiment, our goals were to characterize the role of QAs relative to specialist enemies of gorse and to investigate if QA concentration evolved in invaded regions, where gorse was introduced without these enemies. Our results showed that pod infestation rate by the seed predator Exapion ulicis and infestation by the rust pathogen Uromyces genistae-tinctoriae were negatively correlated to concentration of the QA lupanine. Quinolizidine alkaloid concentration was very variable between individuals, both within and among populations, but it was not different between native and invaded regions, suggesting that no evolution of decreased resistance occurred after gorse lost its enemies. Our study also suggests that QA concentrations are traits integrated into seed predation avoidance strategies of gorse, with plants that mass-fruit in spring but do not escape pod infestation in time being richer in QAs.

  17. Invasive Species May Disrupt Protected Area Networks: Insights from the Pine Wood Nematode Spread in Portugal

    Directory of Open Access Journals (Sweden)

    Begoña de la Fuente

    2018-05-01

    Full Text Available The expansion of invasive alien species is considered a major threat to forest ecosystems and biodiversity. Their potential impacts range from local changes in species composition to wider-scale effects on forest habitat and landscape functioning, although the latter has been relatively little explored in the literature. Here, we assessed the impact of an invasive forest pest, the pine wood nematode (PWN, in the Natura 2000 network of protected areas (PAs in Portugal, the first European country in which PWN was reported. We considered the impacts of the pest’s spread (up to 2016 on individual PAs, in terms of the fraction of their coniferous forest infected, and on the corridors between PAs, which were mapped and prioritized through least-cost path modelling, geographic information system analysis, and the graph-based probability of connectivity metric. We found that PWN by 2016 had spread into 49% of the Portuguese Natura 2000 coniferous forest habitat, while it had invaded 68% of the coniferous forests that form the priority corridors between the PAs. These impacts are likely to be aggravated in the next years, given the pace of PWN expansion and the predicted rates of natural spread to new areas in Portugal and, increasingly likely, in Spain. Our results suggest that the connectivity of PA systems may be significantly disrupted by alien species, and that spatially prioritized control measures can help mitigate the impacts of invasive species on the coherence and functionality of protected area networks such as Natura 2000.

  18. Paving the Way for Invasive Species: Road Type and the Spread of Common Ragweed ( Ambrosia artemisiifolia)

    Science.gov (United States)

    Joly, Martin; Bertrand, Pascale; Gbangou, Roland Y.; White, Marie-Catherine; Dubé, Jean; Lavoie, Claude

    2011-09-01

    Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there is little research on the influence of these types on the spread of invaders. Common ragweed ( Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely (13%) colonized by the plant. A model (53% of variance explained), constructed with only four variables (paved regional roads, paved local roads, recently mown road verges, forest cover), correctly predicted (success rate: 89%) the spatial distribution of common ragweed. Results support the hypothesis that attributes associated with paved roads strongly favour the spread of an opportunistic invasive plant species. Specifically, larger verges and greater disturbance associated with higher traffic volume create propitious conditions for common ragweed. To date, emphasis has been placed on controlling the plant in agricultural fields, even though roadsides are probably a much larger seed source. Strategies for controlling the weed along roads have only focused on major highways, even though the considerable populations along local roads also contribute to the production of pollen. Management prioritizations developed to control common ragweed are thus questionable.

  19. Acacia saligna: an invasive species on the coast of Molise (southern Italy

    Directory of Open Access Journals (Sweden)

    Calabrese V

    2017-02-01

    Full Text Available Italy is one of the European countries most affected by biological invasions. In this study, we focused on the impact of Acacia saligna, an Australian invasive plant species, on the coastal ecosystem’s ecology and biodiversity along the sandy coasts of Molise (southern Italy. We analyzed data from 61 vegetation plots recorded in coastal pine forest and Mediterranean scrub habitats of Molise throughout the preparatory actions of the “LIFE Maestrale” project (NAT/IT/000262. In order to study the ecological impact of Acacia saligna comparing invaded and non-invaded areas, we first assigned the Ellenberg’s indicator values to each plant species, which were then used to relate the presence of Acacia saligna with ecological characteristics of sites through a generalized linear model (GLM. Our results showed a significant positive relationship between the presence of Acacia saligna and high levels of soil nutrients and, on the contrary, a negative relationship with the presence of mesophilic species, which are typical of the community interest habitats of pine forest (2270*. The use of ecological indicators is effective to pinpoint the ecological effects of biological invasions, as well as to evaluate habitat conservation state and to identify vulnerable native species.

  20. Differences in functional traits between invasive and native Amaranthus species under different forms of N deposition

    Science.gov (United States)

    Wang, Congyan; Zhou, Jiawei; Liu, Jun; Jiang, Kun

    2017-08-01

    Differences in functional traits between invasive and native plant species are believed to determine the invasion success of the former. Increasing amounts of anthropogenic nitrogen (N) are continually deposited into natural ecosystems, which may change the relative occurrence of the different N deposition forms (such as NH4-N, NO3-N, and CO(NH2)2-N) naturally deposited. Under high N deposition scenarios, some invasive species may grow faster, gaining advantage over native species. In a greenhouse experiment, we grew invasive and native Amaranthus species from seed both alone and in competition under simulated N enriched environments with different forms of N over 3 months. Then, we measured different leaf traits (i.e., plant height, leaf length, leaf width, leaf shape index, specific leaf area (SLA), and leaf chlorophyll and N concentrations). Results showed that the competition intensity between A. retroflexus and A. tricolor decreased under N deposition. This may be due to the large functional divergence between A. retroflexus and A. tricolor under simulated N deposition. Phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus were significantly lower than in A. tricolor. The lower range of phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may indicate a fitness cost for plastic functional traits under adverse environments. The restricted phenotypic plasticity of SLA and leaf chlorophyll concentration of A. retroflexus may also stabilize leaf construction costs and the growth rate. Meanwhile, the two Amaranthus species possessed greater plasticity in leaf N concentration under NO3-N fertilization, which enhanced their competitiveness.

  1. Monitoring of noble, signal and narrow-clawed crayfish using environmental DNA from freshwater samples

    DEFF Research Database (Denmark)

    Agersnap, Sune; Larsen, William Brenner; Knudsen, Steen Wilhelm

    2017-01-01

    human assisted expansion of non-indigenous signal crayfish Pacifastacus leniusculus that carry and transmit the crayfish plague pathogen. In Denmark, also the non-indigenous narrow-clawed crayfish Astacus leptodactylus has expanded due to anthropogenic activities. Knowledge about crayfish distribution...

  2. Using economic instruments to develop effective management of invasive species: insights from a bioeconomic model.

    Science.gov (United States)

    McDermott, Shana M; Irwin, Rebecca E; Taylor, Brad W

    2013-07-01

    Economic growth is recognized as an important factor associated with species invasions. Consequently, there is increasing need to develop solutions that combine economics and ecology to inform invasive species management. We developed a model combining economic, ecological, and sociological factors to assess the degree to which economic policies can be used to control invasive plants. Because invasive plants often spread across numerous properties, we explored whether property owners should manage invaders cooperatively as a group by incorporating the negative effects of invader spread in management decisions (collective management) or independently, whereby the negative effects of invasive plant spread are ignored (independent management). Our modeling approach used a dynamic optimization framework, and we applied the model to invader spread using Linaria vulgaris. Model simulations allowed us to determine the optimal management strategy based on net benefits for a range of invader densities. We found that optimal management strategies varied as a function of initial plant densities. At low densities, net benefits were high for both collective and independent management to eradicate the invader, suggesting the importance of early detection and eradication. At moderate densities, collective management led to faster and more frequent invader eradication compared to independent management. When we used a financial penalty to ensure that independent properties were managed collectively, we found that the penalty would be most feasible when levied on a property's perimeter boundary to control spread among properties. At the highest densities, the optimal management strategy was "do nothing" because the economic costs of removal were too high relative to the benefits of removal. Spatial variation in L. vulgaris densities resulted in different optimal management strategies for neighboring properties, making a formal economic policy to encourage invasive species removal

  3. How complete is our knowledge of the ecosystem services impacts of Europe's top 10 invasive species?

    Science.gov (United States)

    McLaughlan, C.; Gallardo, B.; Aldridge, D. C.

    2014-01-01

    Invasive non-native species have complex multilevel impacts on their introduced ecosystems, leading to far-ranging effects on fundamental ecosystem services, from the provision of food from that system, to human health and wellbeing. For this reason, there is an emerging interest in basing risk assessments not only on the species' ecological and economic impacts, but also on the effects related to ecosystem services. We investigated the quality and extent of baseline data detailing the effects that the top 10 of the 'worst' invasive species in Europe are having on their adopted ecosystems. The results were striking, as the 10 species showed a wide range of impacts on ecosystem services, a number of which were actually positive for ecosystems and human well-being. For instance, the bivalve Dreissena polymorpha is a prolific biofouler of pipes and boats, but it can improve water quality through its filtration of nuisance algae, a valuable effect that is often overlooked. We found that negative effects, particularly economic ones, were often assumed rather than quantitatively evidenced; for example, the cost of crop damage by species such as Myocastor coypus and Branta canadensis. In general, the evidence for impacts of these 'worst' invaders was severely lacking. We conclude that invasive species management requires prioritization, which should be based on informed and quantified assessment of the potential ecological and economic costs of species (both positive and negative), considered in the proper context of the invader and ecosystem. The Millennium Ecosystem Approach provides a useful framework to undertake such prioritization from a new perspective combining ecological and societal aspects. However, standard guidelines of evaluation are urgently needed in order to unify definitions, methods and evaluation scores.

  4. Invasive species and biodiversity crises: testing the link in the late devonian.

    Directory of Open Access Journals (Sweden)

    Alycia L Stigall

    Full Text Available During the Late Devonian Biodiversity Crisis, the primary driver of biodiversity decline was the dramatic reduction in speciation rates, not elevated extinction rates; however, the causes of speciation decline have been previously unstudied. Speciation, the formation of new species from ancestral populations, occurs by two primary allopatric mechanisms: vicariance, where the ancestral population is passively divided into two large subpopulations that later diverge and form two daughter species, and dispersal, in which a small subset of the ancestral population actively migrates then diverges to form a new species. Studies of modern and fossil clades typically document speciation by vicariance in much higher frequencies than speciation by dispersal. To assess the mechanism behind Late Devonian speciation reduction, speciation rates were calculated within stratigraphically constrained species-level phylogenetic hypotheses for three representative clades and mode of speciation at cladogenetic events was assessed across four clades in three phyla: Arthropoda, Brachiopoda, and Mollusca. In all cases, Devonian taxa exhibited a congruent reduction in speciation rate between the Middle Devonian pre-crisis interval and the Late Devonian crisis interval. Furthermore, speciation via vicariance is almost entirely absent during the crisis interval; most episodes of speciation during this time were due to dispersal. The shutdown of speciation by vicariance during this interval was related to widespread interbasinal species invasions. The lack of Late Devonian vicariance is diametrically opposed to the pattern observed in other geologic intervals, which suggests the loss of vicariant speciation attributable to species invasions during the Late Devonian was a causal factor in the biodiversity crisis. Similarly, modern ecosystems, in which invasive species are rampant, may be expected to exhibit similar shutdown of speciation by vicariance as an outcome of the

  5. Invasive species and biodiversity crises: testing the link in the late devonian.

    Science.gov (United States)

    Stigall, Alycia L

    2010-12-29

    During the Late Devonian Biodiversity Crisis, the primary driver of biodiversity decline was the dramatic reduction in speciation rates, not elevated extinction rates; however, the causes of speciation decline have been previously unstudied. Speciation, the formation of new species from ancestral populations, occurs by two primary allopatric mechanisms: vicariance, where the ancestral population is passively divided into two large subpopulations that later diverge and form two daughter species, and dispersal, in which a small subset of the ancestral population actively migrates then diverges to form a new species. Studies of modern and fossil clades typically document speciation by vicariance in much higher frequencies than speciation by dispersal. To assess the mechanism behind Late Devonian speciation reduction, speciation rates were calculated within stratigraphically constrained species-level phylogenetic hypotheses for three representative clades and mode of speciation at cladogenetic events was assessed across four clades in three phyla: Arthropoda, Brachiopoda, and Mollusca. In all cases, Devonian taxa exhibited a congruent reduction in speciation rate between the Middle Devonian pre-crisis interval and the Late Devonian crisis interval. Furthermore, speciation via vicariance is almost entirely absent during the crisis interval; most episodes of speciation during this time were due to dispersal. The shutdown of speciation by vicariance during this interval was related to widespread interbasinal species invasions. The lack of Late Devonian vicariance is diametrically opposed to the pattern observed in other geologic intervals, which suggests the loss of vicariant speciation attributable to species invasions during the Late Devonian was a causal factor in the biodiversity crisis. Similarly, modern ecosystems, in which invasive species are rampant, may be expected to exhibit similar shutdown of speciation by vicariance as an outcome of the modern biodiversity

  6. Minimizing opportunity costs to aquatic connectivity restoration while controlling an invasive species.

    Science.gov (United States)

    Milt, Austin W; Diebel, Matthew W; Doran, Patrick J; Ferris, Michael C; Herbert, Matthew; Khoury, Mary L; Moody, Allison T; Neeson, Thomas M; Ross, Jared; Treska, Ted; O'Hanley, Jesse R; Walter, Lisa; Wangen, Steven R; Yacobson, Eugene; McIntyre, Peter B

    2018-03-08

    Controlling invasive species is critical for conservation but can have unintended consequences for native species and divert resources away from other efforts. This dilemma occurs on a grand scale in the North American Great Lakes, where dams and culverts block tributary access to habitat of desirable fish species and are a lynchpin of long-standing efforts to limit ecological damage inflicted by the invasive, parasitic sea lamprey (Petromyzon marinus). Habitat restoration and sea-lamprey control create conflicting goals for managing aging infrastructure. We used optimization to minimize opportunity costs of habitat gains for 37 desirable migratory fishes that arose from restricting sea lamprey access (0-25% increase) when selecting barriers for removal under a limited budget (US$1-105 million). Imposing limits on sea lamprey habitat reduced gains in tributary access for desirable species by 15-50% relative to an unconstrained scenario. Additional investment to offset the effect of limiting sea-lamprey access resulted in high opportunity costs for 30 of 37 species (e.g., an additional US$20-80 million for lake sturgeon [Acipenser fulvescens]) and often required ≥5% increase in sea-lamprey access to identify barrier-removal solutions adhering to the budget and limiting access. Narrowly distributed species exhibited the highest opportunity costs but benefited more at less cost when small increases in sea-lamprey access were allowed. Our results illustrate the value of optimization in limiting opportunity costs when balancing invasion control against restoration benefits for diverse desirable species. Such trade-off analyses are essential to the restoration of connectivity within fragmented rivers without unleashing invaders. © 2018 Society for Conservation Biology.

  7. Pre-damage biomass allocation and not invasiveness predicts tolerance to damage in seedlings of woody species in Hawaii.

    Science.gov (United States)

    Lurie, Matthew H; Barton, Kasey E; Daehler, Curtis C

    2017-12-01

    Plant-herbivore interactions have been predicted to play a fundamental role in plant invasions, although support for this assertion from previous research is mixed. While plants may escape from specialist herbivores in their introduced ranges, herbivory from generalists is common. Tolerance traits may allow non-native plants to mitigate the negative consequences of generalist herbivory that they cannot avoid in their introduced range. Here we address whether tolerance to herbivory, quantified as survival and compensatory growth, is associated with plant invasion success in Hawaii and investigate traits that may enhance tolerance in seedlings, the life stage most susceptible to herbivory. In a greenhouse experiment, we measured seedling tolerance to simulated herbivory through mechanical damage (50% leaf removal) of 16 non-native woody plant species differing in invasion status (invasive vs. non-invasive). Seedlings were grown for 2 weeks following damage and analyzed for biomass to determine whether damaged plants could fully compensate for the lost leaf tissue. Over 99% of all seedlings survived defoliation. Although species varied significantly in their levels of compensation, there was no consistent difference between invasive and non-invasive species. Seedlings of 11 species undercompensated and remained substantially smaller than control seedlings 2 weeks after damage; four species were close to compensating, while one species overcompensated. Across species, compensation was positively associated with an increased investment in potential storage reserves, specifically cotyledons and roots, suggesting that these organs provide resources that help seedlings re-grow following damage. Our results add to a growing consensus that pre-damage growth patterns determine tolerance to damage, even in young seedlings which have relatively low biomass. The lack of higher tolerance in highly invasive species may suggest that invaders overcome herbivory barriers to invasion

  8. Species groups occupying different trophic levels respond differently to the invasion of semi-natural vegetation by Solidago canadensis

    NARCIS (Netherlands)

    Groot, de M.; Kleijn, D.; Jogan, N.

    2007-01-01

    We studied the impact of the invasive plant species Solidago canadensis on the species richness of vascular plants and the abundance, species richness and diversity of butterflies, hoverflies and carabid beetles in herbaceous semi-natural habitats near Ljubljana, Slovenia. The species groups were

  9. A framework for sustainable invasive species management: environmental, social and economic objectives

    Science.gov (United States)

    Larson, Diane L.; Phillips-Mao, Laura; Quiram, Gina; Sharpe, Leah; Stark, Rebecca; Sugita, Shinya; Weiler, Annie

    2011-01-01

    Applying the concept of sustainability to invasive species management (ISM) is challenging but necessary, given the increasing rates of invasion and the high costs of invasion impacts and control. To be sustainable, ISM must address environmental, social, and economic factors (or *pillars*) that influence the causes, impacts, and control of invasive species across multiple spatial and temporal scales. Although these pillars are generally acknowledged, their implementation is often limited by insufficient control options and significant economic and political constraints. In this paper, we outline specific objectives in each of these three *pillars* that, if incorporated into a management plan, will improve the plan's likelihood of sustainability. We then examine three case studies that illustrate how these objectives can be effectively implemented. Each pillar reinforces the others, such that the inclusion of even a few of the outlined objectives will lead to more effective management that achieves ecological goals, while generating social support and long-term funding to maintain projects to completion. We encourage agency directors and policy-makers to consider sustainability principles when developing funding schemes, management agendas, and policy.

  10. Moscatilin Inhibits Lung Cancer Cell Motility and Invasion via Suppression of Endogenous Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Akkarawut Kowitdamrong

    2013-01-01

    Full Text Available Lung cancer is the leading cause of death among cancer patients worldwide, and most of them have died from metastasis. Migration and invasion are prerequisite processes associated with high metastasis potential in cancers. Moscatilin, a bibenzyl derivative isolated from the Thai orchid Dendrobium pulchellum, has been shown to have anticancer effect against numerous cancer cell lines. However, little is known regarding the effect of moscatilin on cancer cell migration and invasion. The present study demonstrates that nontoxic concentrations of moscatilin were able to inhibit human nonsmall cell lung cancer H23 cell migration and invasion. The inhibitory effect of moscatilin was associated with an attenuation of endogenous reactive oxygen species (ROS, in which hydroxyl radical (OH∙ was identified as a dominant species in the suppression of filopodia formation. Western blot analysis also revealed that moscatilin downregulated activated focal adhesion kinase (phosphorylated FAK, Tyr 397 and activated ATP-dependent tyrosine kinase (phosphorylated Akt, Ser 473, whereas their parental counterparts were not detectable changed. In conclusion, our results indicate the novel molecular basis of moscalitin-inhibiting lung cancer cell motility and invasion and demonstrate a promising antimetastatic potential of such an agent for lung cancer therapy.

  11. Predicting the geographical distribution of two invasive termite species from occurrence data.

    Science.gov (United States)

    Tonini, Francesco; Divino, Fabio; Lasinio, Giovanna Jona; Hochmair, Hartwig H; Scheffrahn, Rudolf H

    2014-10-01

    Predicting the potential habitat of species under both current and future climate change scenarios is crucial for monitoring invasive species and understanding a species' response to different environmental conditions. Frequently, the only data available on a species is the location of its occurrence (presence-only data). Using occurrence records only, two models were used to predict the geographical distribution of two destructive invasive termite species, Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki. The first model uses a Bayesian linear logistic regression approach adjusted for presence-only data while the second one is the widely used maximum entropy approach (Maxent). Results show that the predicted distributions of both C. gestroi and C. formosanus are strongly linked to urban development. The impact of future scenarios such as climate warming and population growth on the biotic distribution of both termite species was also assessed. Future climate warming seems to affect their projected probability of presence to a lesser extent than population growth. The Bayesian logistic approach outperformed Maxent consistently in all models according to evaluation criteria such as model sensitivity and ecological realism. The importance of further studies for an explicit treatment of residual spatial autocorrelation and a more comprehensive comparison between both statistical approaches is suggested.

  12. A new ostracod (Entocytheridae, Notocytherinae) on New Guinea crayfish1)

    NARCIS (Netherlands)

    Hart, D.G.; Hart, C.W.

    1970-01-01

    In 1967 we examined the crayfish collections in the Rijksmuseum van Natuurlijke Historie, Leiden, to determine if the crayfishes collected in New Guinea in 1954 by Dr. L. B. Holthuis, Dr. L. D. Brongersma, and Dr. M. Boeseman (Boeseman, 1963) were hosts to commensal ostracods. Of the collections

  13. Parasites of crayfish ( P. clarki ) and lobsters ( Macrobrachium ...

    African Journals Online (AJOL)

    Studies on parasites of crayfish and lobsters as indicators of metal pollution in Great Kwa River, Nigeria was evaluated using appropriate instruments for determination of Physicochemical parameters and detection of metals. Formol ether centrifugation method was used for isolation of parasites. A total of 150 crayfish and ...

  14. Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

    Science.gov (United States)

    Burdon, J J; Thrall, P H; Ericson, L

    2013-08-01

    Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Forest legacies, climate change, altered disturbance regimes, invasive species and water

    Science.gov (United States)

    Stohlgren, T.; Jarnevich, C.; Kumar, S.

    2007-01-01

    The factors that must be considered in seeking to predict changes in water availability has been examined. These factors are the following: forest legacies including logging, mining, agriculture, grazing, elimination of large carnivores, human-caused wildfire, and pollution; climate change and stream flow; altered disturbances such as frequency intensity and pattern of wildfires and insect outbreaks as well as flood control; lastly, invasive species like forest pests and pathogens. An integrated approach quantifying the current and past condition trends can be combined with spatial and temporal modeling to develop future change in forest structures and water supply. The key is a combination of geographic information system technologies with climate and land use scenarios, while preventing and minimizing the effects of harmful invasive species.

  16. Biology and impacts of Pacific island invasive species 9. Capra hircus, the feral goat, (Mammalia: Bovidae)

    Science.gov (United States)

    Chynoweth, Mark W.; Litton, Creighton M.; Lepczyk, Christopher A.; Hess, Steve A.; Cordell, Susan

    2013-01-01

    Domestic goats, Capra hircus, were intentionally introduced to numerous oceanic islands beginning in the sixteenth century. The remarkable ability of C. hircus to survive in a variety of conditions has enabled this animal to become feral and impact native ecosystems on islands throughout the world. Direct ecological impacts include consumption and trampling of native plants, leading to plant community modification and transformation of ecosystem structure. While the negative impacts of feral goats are well-known and effective management strategies have been developed to control this invasive species, large populations persist on many islands. This review summarizes the impacts of feral goats on Pacific island ecosystems, and the management strategies available to control this invasive species.

  17. Canopy and knowledge gaps when invasive alien insects remove foundation species.

    Science.gov (United States)

    Marler, Thomas E; Lawrence, John H

    2013-01-01

    The armored scale Aulacaspis yasumatsui invaded the northern range of the cycad Cycas micronesica in 2003, and epidemic tree mortality ensued due to a lack of natural enemies of the insect. We quantified cycad demographic responses to the invasion, but the ecological responses to the selective removal of this foundation species have not been addressed. We use this case to highlight information gaps in our understanding of how alien invasive phytophagous insects force cascading adverse ecosystem changes. The mechanistic role of unique canopy gaps, oceanic island examples and threatened foundation species with distinctive traits are three issues that deserve research efforts in a quest to understand this facet of ecosystem change occurring across multiple settings globally.

  18. Invasive fish species in the largest lakes of Scotland, Northern Ireland, Wales and England: the collective U.K. experience

    OpenAIRE

    Winfield, I.J.; Fletcher, J.M.; James, J.B.

    2011-01-01

    An invasive species is defined as an alien (or introduced or non-native) species whose establishment and spread threaten ecosystems, habitats or species with harm. Such threats to UK lake fish communities have long been appreciated and this review assembles case histories, including new data, from the largest lakes of Scotland, Northern Ireland, Wales and England to examine the hypothesis that at least some of these introductions have become invasive. Loch Lomond in Scotland has experienced s...

  19. Getting the Right Traits: Reproductive and Dispersal Characteristics Predict the Invasiveness of Herbaceous Plant Species

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Lenka; Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2015-01-01

    Roč. 10, č. 4 (2015), s. 1-16,no.e0123634 E-ISSN 1932-6203 R&D Projects: GA ČR GB14-36079G; GA ČR GA206/05/0323 Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : species traits * prediction * invasiveness Subject RIV: EF - Botanics Impact factor: 3.057, year: 2015

  20. Tackling invasive alien species in Europe II: threats and opportunities until 2020

    Czech Academy of Sciences Publication Activity Database

    Piria, M.; Copp, G. H.; Dick, J. T. A.; Duplić, A.; Groom, Q.; Jelić, D.; Lucy, F. E.; Roy, H. E.; Sarat, E.; Simonović, P.; Tomljanović, T.; Tricarico, E.; Weinlander, M.; Adámek, Zdeněk; Bedolfe, S.; Coughlan, N. E.; Davis, E.; Dobrzycka-Krahel, A.; Grgić, Z.; Kırankaya, S. G.; Ekmekci, F. G.; Lajtner, J.; Lukas, J. A. Y.; Koutsikos, N.; Mennen, G. J.; Mitić, B.; Pastorino, P.; Ruokonen, T. J.; Skóra, M. E.; Smith, E. R. C.; Šprem, N.; Tarkan, A. S.; Treer, T.; Vardakas, L.; Vehanen, T.; Vilizzi, L.; Zanella, D.; Caffrey, J. M.

    2017-01-01

    Roč. 8, č. 3 (2017), s. 273-286 E-ISSN 1989-8649. [Freshwater Invasives – Networking for Strategy (FINS-II). Zagreb, 11.07.2016-14.07.2016] Institutional support: RVO:68081766 Keywords : non-native species * legislation * policy * environmental management * sequential rank voting * scoring system Subject RIV: EH - Ecology, Behaviour OBOR OECD: Biodiversity conservation Impact factor: 1.439, year: 2016

  1. Mapping of incidence and management of invasive species Fallopia japonica at selected locations of northwestern Slovakia

    International Nuclear Information System (INIS)

    Paukova, Z.; Krskova, L.

    2011-01-01

    Mapping of one of the most dangerous invasive species Fallopia japonica was conducted at selected locations of northwestern Slovakia: in the cadastral territory of Zazriva, in the village Parnica towards Kralovany, in the village Kralovany and the city of Dolny Kubin - Zaskalie, stretch Timravina in the Lower Orava in late summer and early autumn 2009. We recorded by field survey 24 invading Japanese knotweed in the area of 12.238 m 2 . (authors)

  2. Modeling disturbance-based native invasive species control and its implications for management.

    Science.gov (United States)

    Shackelford, Nancy; Renton, Michael; Perring, Michael P; Hobbs, Richard J

    2013-09-01

    Shifts in disturbance regime have often been linked to invasion in systems by native and nonnative species. This process can have negative effects on biodiversity and ecosystem function. Degradation may be ameliorated by the reinstatement of the disturbance regimes, such as the reintroduction of fire in pyrogenic systems. Modeling is one method through which potential outcomes of different regimes can be investigated. We created a population model to examine the control of a native invasive that is expanding and increasing in abundance due to suppressed fire. Our model, parameterized with field data from a case study of the tree Allocasuarina huegeliana in Australian sandplain heath, simulated different fire return intervals with and without the additional management effort of mechanical removal of the native invader. Population behavior under the different management options was assessed, and general estimates of potential biodiversity impacts were compared. We found that changes in fire return intervals made no significant difference in the increase and spread of the population. However, decreased fire return intervals did lower densities reached in the simulated heath patch as well as the estimated maximum biodiversity impacts. When simulating both mechanical removal and fire, we found that the effects of removal depended on the return intervals and the strategy used. Increase rates were not significantly affected by any removal strategy. However, we found that removal, particularly over the whole patch rather than focusing on satellite populations, could decrease average and maximum densities reached and thus decrease the predicted biodiversity impacts. Our simulation model shows that disturbance-based management has the potential to control native invasion in cases where shifted disturbance is the likely driver of the invasion. The increased knowledge gained through the modeling methods outlined can inform management decisions in fire regime planning that

  3. Unprecedented carbon accumulation in mined soils: the synergistic effect of resource input and plant species invasion.

    Science.gov (United States)

    Silva, Lucas C R; Corrêa, Rodrigo S; Doane, Timothy A; Pereira, Engil I P; Horwath, William R

    2013-09-01

    Opencast mining causes severe impacts on natural environments, often resulting in permanent damage to soils and vegetation. In the present study we use a 14-year restoration chronosequence to investigate how resource input and spontaneous plant colonization promote the revegetation and reconstruction of mined soils in central Brazil. Using a multi-proxy approach, combining vegetation surveys with the analysis of plant and soil isotopic abundances (delta13C and delta15N) and chemical and physical fractionation of organic matter in soil profiles, we show that: (1) after several decades without vegetation cover, the input of nutrient-rich biosolids into exposed regoliths prompted the establishment of a diverse plant community (> 30 species); (2) the synergistic effect of resource input and plant colonization yielded unprecedented increases in soil carbon, accumulating as chemically stable compounds in occluded physical fractions and reaching much higher levels than observed in undisturbed ecosystems; and (3) invasive grasses progressively excluded native species, limiting nutrient availability, but contributing more than 65% of the total accumulated soil organic carbon. These results show that soil-plant feedbacks regulate the amount of available resources, determining successional trajectories and alternative stable equilibria in degraded areas undergoing restoration. External inputs promote plant colonization, soil formation, and carbon sequestration, at the cost of excluding native species. The introduction of native woody species would suppress invasive grasses and increase nutrient availability, bringing the system closer to its original state. However, it is difficult to predict whether soil carbon levels could be maintained without the exotic grass cover. We discuss theoretical and practical implications of these findings, describing how the combination of resource manipulation and management of invasive species could be used to optimize restoration strategies

  4. Optimal surveillance strategy for invasive species management when surveys stop after detection.

    Science.gov (United States)

    Guillera-Arroita, Gurutzeta; Hauser, Cindy E; McCarthy, Michael A

    2014-05-01

    Invasive species are a cause for concern in natural and economic systems and require both monitoring and management. There is a trade-off between the amount of resources spent on surveying for the species and conducting early management of occupied sites, and the resources that are ultimately spent in delayed management at sites where the species was present but undetected. Previous work addressed this optimal resource allocation problem assuming that surveys continue despite detection until the initially planned survey effort is consumed. However, a more realistic scenario is often that surveys stop after detection (i.e., follow a "removal" sampling design) and then management begins. Such an approach will indicate a different optimal survey design and can be expected to be more efficient. We analyze this case and compare the expected efficiency of invasive species management programs under both survey methods. We also evaluate the impact of mis-specifying the type of sampling approach during the program design phase. We derive analytical expressions that optimize resource allocation between monitoring and management in surveillance programs when surveys stop after detection. We do this under a scenario of unconstrained resources and scenarios where survey budget is constrained. The efficiency of surveillance programs is greater if a "removal survey" design is used, with larger gains obtained when savings from early detection are high, occupancy is high, and survey costs are not much lower than early management costs at a site. Designing a surveillance program disregarding that surveys stop after detection can result in an efficiency loss. Our results help guide the design of future surveillance programs for invasive species. Addressing program design within a decision-theoretic framework can lead to a better use of available resources. We show how species prevalence, its detectability, and the benefits derived from early detection can be considered.

  5. Considering native and exotic terrestrial reptiles in island invasive species eradication programmes in the Tropical Pacific

    Science.gov (United States)

    Fisher, Richard N.; Veitch, C.R.; Clout, Mike N.; Towns, D. R.

    2010-01-01

    Most island restoration projects with reptiles, either as direct beneficiaries of conservation or as indicators of recovery responses, have been on temperate or xeric islands. There have been decades of research, particularly on temperate islands in New Zealand, on the responses of native reptiles to mammal eradications but very few studies in tropical insular systems. Recent increases in restoration projects involving feral mammal eradications in the tropical Pacific have led to several specific challenges related to native and invasive reptiles. This paper reviews these challenges and discusses some potential solutions to them. The first challenge is that the tropical Pacific herpetofauna is still being discovered, described and understood. There is thus incomplete knowledge of how eradication activities may affect these faunas and the potential risks facing critical populations of these species from these eradication actions. The long term benefit of the removal of invasives is beneficial, but the possible short term impacts to small populations on small islands might be significant. The second challenge is that protocols for monitoring the responses of these species are not well documented but are often different from those used in temperate or xeric habitats. Lizard monitoring techniques used in the tropical Pacific are discussed. The third challenge involves invasive reptiles already in the tropical Pacific, some of which could easily spread accidentally through eradication and monitoring operations. The species posing the greatest threats in this respect are reviewed, and recommendations for biosecurity concerning these taxa are made.

  6. Discrimination of Species and Hybrid Detection in Myriophyllum Spp.: an Introduction to Biodiversity Conservation and Invasion Avoidance

    Directory of Open Access Journals (Sweden)

    R Ghahramanzadeh

    2014-03-01

    Full Text Available Minimizing economical loss through introduction of invasive alien species (IAS in local ecosystem is one of the most important issues in biosecurity. The hybridization potential between non-indigenous and native species has raised concerns due mainly to introgression, which can cause extirpation of native species through gene contamination. In the present study, 71 samples belonging to 12 species from Myriophyllum genus were assessed in Plant Breeding group of Wageningen University. Internal transcribed spacer (ITS was used for identification of invasive species from related native and possible hybrid plants. The result showed that based on universal application, high sequence divergence and species discrimination, ITS is a powerful sequence for the identification of invasive species from related non-invasive foreign and native species. In contrast to morphological data, ITS grouped suspected hybrid plants in to M. heterophyllum and demonstrated that they have not resulted from hybridization. These observations suggest that multiple introduction and genetic recombination among different introduced genotypes or genetic pools could be reasons of non-flowering in suspected hybrid plants. Results showed that molecular markers enable to distinguish invasive plant species from their most closely related congeners. This could be helpful with enforcing a ban on important of such invasive which can help to plant ecosystem and biodiversity stability.

  7. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes.

    Science.gov (United States)

    Kowalski, Kurt P; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michèle; Lillard, Elizabeth; McCormick, Melissa K; Nelson, Eric; Torres, Monica; White, James; Wilcox, Douglas A

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  8. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes

    Science.gov (United States)

    Kowalski, Kurt P.; Bacon, Charles R.; Bickford, Wesley A.; Braun, Heather A.; Clay, Keith; Leduc-Lapierre, Michele; Lillard, Elizabeth; McCormick, Melissa K.; Nelson, Eric; Torres, Monica; White, James W. C.; Wilcox, Douglas A.

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis andPhragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  9. European hare Lepus europaeus(Lagomorpha: Leporidae an invasive species in Peru

    Directory of Open Access Journals (Sweden)

    Horacio Zeballos

    2013-06-01

    Full Text Available We describe the current distribution of the European hare, Lepus europaeus, in Peru which currently covers the highlands, Andean valleys, surrounding areas of the Titicaca Lake and coastal irrigations; in Arequipa, Cusco, Moquegua, Puno and Tacna departments. Based on its current distribution we developed models of potential distribution of this species, which would forecast this species in northern Peru. We make recommendations on the main issues that should be studied in Peru, and the possible consequences of their invasive process of in Peru.

  10. New invasive species of aphids (Hemiptera, Aphididae in Serbia and Montenegro

    Directory of Open Access Journals (Sweden)

    Petrović-Obradović Olivera

    2010-01-01

    Full Text Available Three new invasive species of aphids have been found in Serbia: Chaitophorus populifolli Essig, Myzocallis walshii (Monell and Trichosiphonaphis polygonifoliae (Shinji and two have been found in Montenegro: Aphis illinoisensis Shimer and Tinocallis kahawaluokalani (Kirkaldy. A. illinoisensis is a pest of the grapevine, T. polygonifoliae, feeds on a decorative shrub (Lonicera and the other three feed on trees (Populus, Quercus and Lagerostroemia. Three of the species are American aphids and two are of Asian origin. Their morphology, illustrated by original drawings and data on the biology and distribution are given. .

  11. INVASIVE ALIEN PLANT SPECIES USED FOR THE TREATMENT OF VARIOUS DISEASES IN LIMPOPO PROVINCE, SOUTH AFRICA.

    Science.gov (United States)

    Maema, Lesibana Peter; Potgieter, Martin; Mahlo, Salome Mamokone

    2016-01-01

    Invasive alien plant species (IAPs) are plants that have migrated from one geographical region to non-native region either intentional or unintentional. The general view of IAPs in environment is regarded as destructive to the ecosystem and they pose threat to native vegetation and species. However, some of these IAPS are utilized by local inhabitants as a substitute for scarce indigenous plants. The aim of the study is to conduct ethnobotanical survey on medicinal usage of invasive plant species in Waterberg District, Limpopo Province, South Africa. An ethnobotanical survey on invasive plant species was conducted to distinguish species used for the treatment of various ailments in the Waterberg, District in the area dominated by Bapedi traditional healers. About thirty Bapedi traditional healers (30) were randomly selected via the snowball method. A guided field work by traditional healers and a semi-structured questionnaire was used to gather information from the traditional healers. The questionnaire was designed to gather information on the local name of plants, plant parts used and methods of preparation which is administered by the traditional healers. The study revealed that Schinus molle L., Catharanthus roseus (L.), Datura stramonium L., Opuntia stricta (Haw.) Haw., Opuntia ficus- indica, Sambucus canadensis L., Ricinus communis L., Melia azedarch L., Argemone ochroleuca and Eriobotrya japónica are used for treatment of various diseases such as chest complaint, blood purification, asthma, hypertension and infertility. The most plant parts that were used are 57.6% leaves, followed by 33.3% roots, and whole plant, seeds and bark at 3% each. Noticeably, most of these plants are cultivated (38%), followed by 28% that are common to the study area, 20% abundant, 12% wild, and 3% occasionally. Schinus molle is the most frequently used plant species for the treatment of various ailments in the study area. National Environmental Management Biodiversity Act (NEMBA

  12. Acute toxicity of chlorantraniliprole to non-target crayfish (Procambarus clarkii) associated with rice-crayfish cropping systems.

    Science.gov (United States)

    Barbee, Gary C; McClain, W Ray; Lanka, Srinivas K; Stout, Michael J

    2010-09-01

    Chlorantraniliprole, a novel anthranilic diamide insecticide, was recently introduced into the United States where rice-crayfish crop rotations are practiced to control rice water weevil (Lissorhoptrus oryzophilus Kuschel) infestations. Chlorantraniliprole has high margins of mammalian safety and excellent insecticidal efficacy, but its toxicity to non-target crayfish is uncertain. In this study, the acute toxicity of chlorantraniliprole to the red swamp crayfish Procambarus clarkii Girard was determined using aquatic and feeding assays. The aquatic 96 h median lethal toxicity (LC(50)) data indicate that technical-grade chlorantraniliprole is highly toxic (US EPA category) to crayfish with an LC(50) of 951 microg L(-1) (95% CL = 741-1118 microg L(-1)). A no observed effect concentration (NOEC) of 480 microg L(-1) was recorded. Neither the 36 day chronic feeding study, where crayfish fed on chlorantraniliprole-treated rice seed in aquaria, nor the 144 h acute feeding test, where crayfish fed on rice seeds treated with chlorantraniliprole, produced mortality or abnormal behavior. Chlorantraniliprole is three orders of magnitude less acutely toxic to P. clarkii than lambda-cyhalothrin and etofenprox, two pyrethroid insecticides also used in rice, and is less likely to cause acute crayfish toxicity in rice pond ecosystems. Based on acute toxicity data, the use of chlorantraniliprole should be more compatible with rice-crayfish crop rotations than pyrethroids. (c) 2010 Society of Chemical Industry.

  13. Biological Invasion Influences the Outcome of Plant-Soil Feedback in the Invasive Plant Species from the Brazilian Semi-arid.

    Science.gov (United States)

    de Souza, Tancredo Augusto Feitosa; de Andrade, Leonaldo Alves; Freitas, Helena; da Silva Sandim, Aline

    2017-05-30

    Plant-soil feedback is recognized as the mutual interaction between plants and soil microorganisms, but its role on the biological invasion of the Brazilian tropical seasonal dry forest by invasive plants still remains unclear. Here, we analyzed and compared the arbuscular mycorrhizal fungi (AMF) communities and soil characteristics from the root zone of invasive and native plants, and tested how these AMF communities affect the development of four invasive plant species (Cryptostegia madagascariensis, Parkinsonia aculeata, Prosopis juliflora, and Sesbania virgata). Our field sampling revealed that AMF diversity and frequency of the Order Diversisporales were positively correlated with the root zone of the native plants, whereas AMF dominance and frequency of the Order Glomerales were positively correlated with the root zone of invasive plants. We grew the invasive plants in soil inoculated with AMF species from the root zone of invasive (I changed ) and native (I unaltered ) plant species. We also performed a third treatment with sterilized soil inoculum (control). We examined the effects of these three AMF inoculums on plant dry biomass, root colonization, plant phosphorous concentration, and plant responsiveness to mycorrhizas. We found that I unaltered and I changed promoted the growth of all invasive plants and led to a higher plant dry biomass, mycorrhizal colonization, and P uptake than control, but I changed showed better results on these variables than I unaltered . For plant responsiveness to mycorrhizas and fungal inoculum effect on plant P concentration, we found positive feedback between changed-AMF community (I changed ) and three of the studied invasive plants: C. madagascariensis, P. aculeata, and S. virgata.

  14. Faster N Release, but Not C Loss, From Leaf Litter of Invasives Compared to Native Species in Mediterranean Ecosystems

    Directory of Open Access Journals (Sweden)

    Guido Incerti

    2018-04-01

    Full Text Available Plant invasions can have relevant impacts on biogeochemical cycles, whose extent, in Mediterranean ecosystems, have not yet been systematically assessed comparing litter carbon (C and nitrogen (N dynamics between invasive plants and native communities. We carried out a 1-year litterbag experiment in 4 different plant communities (grassland, sand dune, riparian and mixed forests on 8 invasives and 24 autochthonous plant species, used as control. Plant litter was characterized for mass loss, N release, proximate lignin and litter chemistry by 13C CPMAS NMR. Native and invasive species showed significant differences in litter chemical traits, with invaders generally showing higher N concentration and lower lignin/N ratio. Mass loss data revealed no consistent differences between native and invasive species, although some woody and vine invaders showed exceptionally high decomposition rate. In contrast, N release rate from litter was faster for invasive plants compared to native species. N concentration, lignin content and relative abundance of methoxyl and N-alkyl C region from 13C CPMAS NMR spectra were the parameters that better explained mass loss and N mineralization rates. Our findings demonstrate that during litter decomposition invasive species litter has no different decomposition rates but greater N release rate compared to natives. Accordingly, invasives are expected to affect N cycle in Mediterranean plant communities, possibly promoting a shift of plant assemblages.

  15. Incentivizing the public to support invasive species management: eurasian milfoil reduces lakefront property values.

    Science.gov (United States)

    Olden, Julian D; Tamayo, Mariana

    2014-01-01

    Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum) invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing) and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995-2006) in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA). After accounting for structural (e.g., house size), locational (e.g., boat launch), and environmental characteristics (e.g., water clarity) of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price), corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue), justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.

  16. Incentivizing the public to support invasive species management: eurasian milfoil reduces lakefront property values.

    Directory of Open Access Journals (Sweden)

    Julian D Olden

    Full Text Available Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995-2006 in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA. After accounting for structural (e.g., house size, locational (e.g., boat launch, and environmental characteristics (e.g., water clarity of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price, corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue, justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.

  17. Mucor nidicola sp. nov., a fungal species isolated from an invasive paper wasp nest.

    Science.gov (United States)

    Madden, A A; Stchigel, A M; Guarro, J; Sutton, D; Starks, P T

    2012-07-01

    A strain of a novel mucoralean fungus was isolated from a nest of the invasive paper wasp, Polistes dominulus. Phylogenetic analysis based on the internal transcribed spacer (ITS) regions and 5.8S rRNA gene sequences, along with physiological tests, revealed that this strain represents a novel species within the genus Mucor. The novel species also includes a representative that had previously been characterized as part of the Mucor hiemalis complex. Unlike the type strain of M. hiemalis, these two strains can grow at 37 °C and sporulate at 35 °C. Here, we present a partial resolution of the M. hiemalis species complex and propose the novel species Mucor nidicola sp. nov. to accommodate the isolate; the type strain of M. nidicola is F53(T) (=NRRL 54520(T)=UAMH 11442(T)=CBS 130359(T)).

  18. Potential problems of removing one invasive species at a time: a meta-analysis of the interactions between invasive vertebrates and unexpected effects of removal programs.

    Science.gov (United States)

    Ballari, Sebastián A; Kuebbing, Sara E; Nuñez, Martin A

    2016-01-01

    Although the co-occurrence of nonnative vertebrates is a ubiquitous global phenomenon, the study of interactions between invaders is poorly represented in the literature. Limited understanding of the interactions between co-occurring vertebrates can be problematic for predicting how the removal of only one invasive-a common management scenario-will affect native communities. We suggest a trophic food web framework for predicting the effects of single-species management on native biodiversity. We used a literature search and meta-analysis to assess current understanding of how the removal of one invasive vertebrate affects native biodiversity relative to when two invasives are present. The majority of studies focused on the removal of carnivores, mainly within aquatic systems, which highlights a critical knowledge gap in our understanding of co-occurring invasive vertebrates. We found that removal of one invasive vertebrate caused a significant negative effect on native species compared to when two invasive vertebrates were present. These unexpected results could arise because of the positioning and hierarchy of the co-occurring invasives in the food web (e.g., carnivore-carnivore or carnivore-herbivore). We consider that there are important knowledge gaps to determinate the effects of multiple co-existing invaders on native ecosystems, and this information could be precious for management.

  19. Practical disinfection chemicals for fishing and crayfishing gear against crayfish plague transfer

    Directory of Open Access Journals (Sweden)

    Jussila J.

    2014-01-01

    Full Text Available We tested four commercial disinfectants against crayfish plague (Aphanomyces astaci spores in both aquatic solutions and with material mimicking fishing and crayfishing gear, e.g. traps, ropes, mesh, etc. The tested disinfectants were Proxitane®5:14, Proxitane®12:20, Wofasteril®E400, Virkon®S and hydrogen peroxide. The effects of the chemicals were initially tested in liquid zoospore cultures and the effective concentrations were then further tested using clean and dirty model materials (PP sheet, nylon rope, cotton fabric contaminated with A. astaci spore solutions. The disinfectants effective against infective crayfish plague spores with both clean and dirty model materials were Proxinate®5:14 (effective concentration was 30 mg·L-1 of PAA and Virkon®S (3 g·L-1, while Proxinate®12:20 (10 mg·L-1 of PAA and Wofasteril®E400 (30 mg·L-1 of PAA worked only with clean model materials. Hydrogen peroxide was not effective in the tested concentrations and conditions. Based on the results, the disinfectants most suitable for the fishing and crayfishing gear disinfection would be Proxitane®5:14 and Virkon®S, with the condition that all the gear should be thoroughly cleaned of organic matter to ensure inactivation of A. astaci spores.

  20. Invasive rats on tropical islands: Their population biology and impacts on native species

    Directory of Open Access Journals (Sweden)

    Grant A. Harper

    2015-01-01

    Full Text Available The three most invasive rat species, black or ship rat Rattus rattus, brown or Norway rats, R. norvegicus and Pacific rat, R. exulans have been incrementally introduced to islands as humans have explored the world’s oceans. They have caused serious deleterious effects through predation and competition, and extinction of many species on tropical islands, many of which are biodiversity hotspots. All three rat species are found in virtually all habitat types, including mangrove and arid shrub land. Black rats tend to dominate the literature but despite this the population biology of invasive rats, particularly Norway rats, is poorly researched on tropical islands. Pacific rats can often exceed population densities of well over 100 rats ha−1 and black rats can attain densities of 119 rats ha−1, which is much higher than recorded on most temperate islands. High densities are possibly due to high recruitment of young although the data to support this are limited. The generally aseasonally warm climate can lead to year-round breeding but can be restricted by either density-dependent effects interacting with resource constraints often due to aridity. Apparent adverse impacts on birds have been well recorded and almost all tropical seabirds and land birds can be affected by rats. On the Pacific islands, black rats have added to declines and extinctions of land birds caused initially by Pacific rats. Rats have likely caused unrecorded extinctions of native species on tropical islands. Further research required on invasive rats on tropical islands includes the drivers of population growth and carrying capacities that result in high densities and how these differ to temperate islands, habitat use of rats in tropical vegetation types and interactions with other tropical species, particularly the reptiles and invertebrates, including crustaceans.

  1. Integrated monitoring and information systems for managing aquatic invasive species in a changing climate

    Science.gov (United States)

    Lee, Henry; Reusser, Deborah A.; Olden, Julian D.; Smith, Scott S.; Graham, Jim; Burkett, Virginia; Dukes, Jeffrey S.; Piorkowski, Robert J.; Mcphedran, John

    2008-01-01

    Changes in temperature, precipitation, and other climatic drivers and sea-level rise will affect populations of existing native and non-native aquatic species and the vulnerability of aquatic environments to new invasions. Monitoring surveys provide the foundation for assessing the combined effects of climate change and invasions by providing baseline biotic and environmental conditions, although the utility of a survey depends on whether the results are quantitative or qualitative, and other design considerations. The results from a variety of monitoring programs in the United States are available in integrated biological information systems, although many include only non-native species, not native species. Besides including natives, we suggest these systems could be improved through the development of standardized methods that capture habitat and physiological requirements and link regional and national biological databases into distributed Web portals that allow drawing information from multiple sources. Combining the outputs from these biological information systems with environmental data would allow the development of ecological-niche models that predict the potential distribution or abundance of native and non-native species on the basis of current environmental conditions. Environmental projections from climate models can be used in these niche models to project changes in species distributions or abundances under altered climatic conditions and to identify potential high-risk invaders. There are, however, a number of challenges, such as uncertainties associated with projections from climate and niche models and difficulty in integrating data with different temporal and spatial granularity. Even with these uncertainties, integration of biological and environmental information systems, niche models, and climate projections would improve management of aquatic ecosystems under the dual threats of biotic invasions and climate change

  2. Remote sensing of California estuaries: Monitoring climate change and invasive species

    Science.gov (United States)

    Mulitsch, Melinda Jennifer

    The spread of invasive species and climate change are among the most serious global environmental threats. The goal of this dissertation was to link inter-annual climate change and biological invasions at a landscape scale using novel remote sensing techniques applied to the San Francisco Bay/Sacramento- San Joaquin Delta Estuary. I evaluated the use of hyperspectral imagery for detecting invasive aquatic species in the Delta using 3 m HyMap hyperspectral imagery. The target invasive aquatics weeds were the emergent water hyacinth (Eichhornia crassipes) and the submerged Brazilian waterweed (Egeria densa). Data were analyzed using linear spectral mixture analysis (SMA). The results show the weeds were mapped with a classification accuracy of 90.6% compared to 2003 sample sites and 82.6% accuracy compared to 2004 sample sites. Brazilian waterweed locations were successfully mapped but the abundances were overestimated because we did not separate it from other submerged aquatic vegatation (SAV). I evaluated 3 m HyMap imagery, from 2004, for SAV species in the Delta, including: Brazilian waterweed ( Egeria densa), Eurasian watermilfoil (Myriophyllum spicatum ), curlyleaf pondweed (Potamogeton crispus), coontail (Ceratophyllum demersum), American pondweed (Potamogeton nodosus), fanwort (Cabomba caroliniana), and common elodea (Elodea canadensis). Data were analyzed using SMA with a classification accuracy of 84.4%. Spectral simulations of Brazilian waterweed and American pondweed show how spectral properties can change at different water depths and varying water quality. Finally I address the effect of inter-annual climate change on the estuary ecology in the San Francisco Bay by analyzing current (2002) and historical (1994-1996) Airborne Visible Infrared Imaging Spectrometer (AVIRIS) datasets to map salt marsh species distribution. The species in the estuary, Salicornia virginica, Spartinia foliosa, Scirpus robustus, and Distichlis spicata undergo dramatic changes in

  3. Targeted research to improve invasive species management: yellow crazy ant Anoplolepis gracilipes in Samoa.

    Science.gov (United States)

    Hoffmann, Benjamin D; Auina, Saronna; Stanley, Margaret C

    2014-01-01

    Lack of biological knowledge of invasive species is recognised as a major factor contributing to eradication failure. Management needs to be informed by a site-specific understanding of the invasion system. Here, we describe targeted research designed to inform the potential eradication of the invasive yellow crazy ant Anoplolepis gracilipes on Nu'utele island, Samoa. First, we assessed the ant's impacts on invertebrate biodiversity by comparing invertebrate communities between infested and uninfested sites. Second, we investigated the timing of production of sexuals and seasonal variation of worker abundance and nest density. Third, we investigated whether an association existed between A. gracilipes and carbohydrate sources. Within the infested area there were few other ants larger than A. gracilipes, as well as fewer spiders and crabs, indicating that A. gracilipes is indeed a significant conservation concern. The timing of male reproduction appears to be consistent with places elsewhere in the world, but queen reproduction was outside of the known reproductive period for this species in the region, indicating that the timing of treatment regimes used elsewhere are not appropriate for Samoa. Worker abundance and nest density were among the highest recorded in the world, being greater in May than in October. These abundance and nest density data form baselines for quantifying treatment efficacy and set sampling densities for post-treatment assessments. The number of plants and insects capable of providing a carbohydrate supply to ants were greatest where A. gracilipes was present, but it is not clear if this association is causal. Regardless, indirectly controlling ant abundance by controlling carbohydrate supply appears to be promising avenue for research. The type of targeted, site-specific research such as that described here should be an integral part of any eradication program for invasive species to design knowledge-based treatment protocols and determine

  4. Regina rigida (glossy crayfish snake)

    Science.gov (United States)

    David A. Steen; James A. Stiles; Sierra H. Stiles; Craig Guyer; Josh B. Pierce; D. Craig Rudolph; Lora L. Smith

    2011-01-01

    The overland movements and upland habitat use of wetland-associated reptiles has important conservation implications (Semlitsch and Bodie 2003. Conserv. BioI. 17:1219-1228). However, for many species, particularly snakes, we lack a basic understanding of spatial ecology and habitat use. Regina rigida is a poorly known species for which "observations of any kind...

  5. Leaf litter traits of invasive species slow down decomposition compared to Spanish natives: a broad phylogenetic comparison.

    Science.gov (United States)

    Godoy, Oscar; Castro-Díez, Pilar; Van Logtestijn, Richard S P; Cornelissen, Johannes H C; Valladares, Fernando

    2010-03-01

    Leaf traits related to the performance of invasive alien species can influence nutrient cycling through litter decomposition. However, there is no consensus yet about whether there are consistent differences in functional leaf traits between invasive and native species that also manifest themselves through their "after life" effects on litter decomposition. When addressing this question it is important to avoid confounding effects of other plant traits related to early phylogenetic divergences and to understand the mechanism underlying the observed results to predict which invasive species will exert larger effects on nutrient cycling. We compared initial leaf litter traits, and their effect on decomposability as tested in standardized incubations, in 19 invasive-native pairs of co-familial species from Spain. They included 12 woody and seven herbaceous alien species representative of the Spanish invasive flora. The predictive power of leaf litter decomposition rates followed the order: growth form > family > status (invasive vs. native) > leaf type. Within species pairs litter decomposition tended to be slower and more dependent on N and P in invaders than in natives. This difference was likely driven by the higher lignin content of invader leaves. Although our study has the limitation of not representing the natural conditions from each invaded community, it suggests a potential slowing down of the nutrient cycle at ecosystem scale upon invasion.

  6. Meta-analysis reveals evolution in invasive plant species but little support for Evolution of Increased Competitive Ability (EICA).

    Science.gov (United States)

    Felker-Quinn, Emmi; Schweitzer, Jennifer A; Bailey, Joseph K

    2013-03-01

    Ecological explanations for the success and persistence of invasive species vastly outnumber evolutionary hypotheses, yet evolution is a fundamental process in the success of any species. The Evolution of Increased Competitive Ability (EICA) hypothesis (Blossey and Nötzold 1995) proposes that evolutionary change in response to release from coevolved herbivores is responsible for the success of many invasive plant species. Studies that evaluate this hypothesis have used different approaches to test whether invasive populations allocate fewer resources to defense and more to growth and competitive ability than do source populations, with mixed results. We conducted a meta-analysis of experimental tests of evolutionary change in the context of EICA. In contrast to previous reviews, there was no support across invasive species for EICA's predictions regarding defense or competitive ability, although invasive populations were more productive than conspecific native populations under noncompetitive conditions. We found broad support for genetically based changes in defense and competitive plant traits after introduction into new ranges, but not in the manner suggested by EICA. This review suggests that evolution occurs as a result of plant introduction and population expansion in invasive plant species, and may contribute to the invasiveness and persistence of some introduced species.

  7. Invasive species' leaf traits and dissimilarity from natives shape their impact on nitrogen cycling: a meta-analysis.

    Science.gov (United States)

    Lee, Marissa R; Bernhardt, Emily S; van Bodegom, Peter M; Cornelissen, J Hans C; Kattge, Jens; Laughlin, Daniel C; Niinemets, Ülo; Peñuelas, Josep; Reich, Peter B; Yguel, Benjamin; Wright, Justin P

    2017-01-01

    Many exotic species have little apparent impact on ecosystem processes, whereas others have dramatic consequences for human and ecosystem health. There is growing evidence that invasions foster eutrophication. We need to identify species that are harmful and systems that are vulnerable to anticipate these consequences. Species' traits may provide the necessary insights. We conducted a global meta-analysis to determine whether plant leaf and litter functional traits, and particularly leaf and litter nitrogen (N) content and carbon: nitrogen (C : N) ratio, explain variation in invasive species' impacts on soil N cycling. Dissimilarity in leaf and litter traits among invaded and noninvaded plant communities control the magnitude and direction of invasion impacts on N cycling. Invasions that caused the greatest increases in soil inorganic N and mineralization rates had a much greater litter N content and lower litter C : N in the invaded than the reference community. Trait dissimilarities were better predictors than the trait values of invasive species alone. Quantifying baseline community tissue traits, in addition to those of the invasive species, is critical to understanding the impacts of invasion on soil N cycling. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  8. Inventory of Invasive Plant Species along the corridor of Kawah Ijen Nature Tourism Park, Banyuwangi, East Java

    Directory of Open Access Journals (Sweden)

    Lia Hapsari

    2014-01-01

    Full Text Available A field survey was conducted in November 2013 to inventory invasive plant species present along the corridor of Kawah Ijen Nature Tourism Park exploratively. Result showed that there were 11 plant species found abundantly along the corridor. Typical native species were dominated by Cyathea contaminans, Casuarina junghuhniana and Vaccinium varingiaefolium. Three species were determined as invasive alien species i.e. Chromolaena odorata, Acacia decurrens and Blumea lacera whereas five species were determined as native species but potential invaders i.e. Rubus moluccanus, Melastoma malabatrichum, Polygonum barbatum, Debregeasia longifolia and Pteridium aquilinum. In term of tourism particularly on nature-based destinations enable moving in and out of invasive alien species due to opening the access of some natural protected areas. The environmental impact of an alien species whether it becomes invasive at its destination depends on its biological key point,  what ecological role the species may play, and on additional factors such as its tolerance of the gross features of the environment in the new range. Keyword: invasive plants, corridor, Kawah Ijen, Nature Tourism Park, Banyuwangi

  9. Reactive oxygen species induced by Streptococcus pyogenes invasion trigger apoptotic cell death in infected epithelial cells.

    Science.gov (United States)

    Aikawa, Chihiro; Nozawa, Takashi; Maruyama, Fumito; Tsumoto, Kohei; Hamada, Shigeyuki; Nakagawa, Ichiro

    2010-06-01

    Streptococcus pyogenes (group A streptococcus, GAS), one of the most common pathogens of humans, attaches and invades into human pharyngeal or skin epithelial cells. We have previously reported that induction of apoptosis is associated with GAS invasion, which induces mitochondrial dysfunction and apoptotic cell death. We demonstrate here that GAS-induced apoptosis is mediated by reactive oxygen species (ROS) production. Both the induction of apoptosis and ROS production markedly increased upon invasion of wild-type GAS strain JRS4 into HeLa cells; however, the apoptotic response was not observed in fibronectin-binding protein F1-disrupted mutant SAM1-infected cells. In Bcl-2-overexpressing HeLa cells (HBD98-2-4), the induction of apoptosis, ROS production and mitochondrial dysfunction were significantly suppressed, whereas the numbers of invaded GAS was not different between HeLa (mock cells) and the HeLa HBD98-2-4 cells. Whereas Rac1 activation occurred during GAS invasion, ROS production in GAS-infected cells was clearly inhibited by transfection with the Rac1 mutants (L37 or V12L37), but not by the dominant active mutant (V12L61) or by the dominant negative mutant (N17). These observations indicate that GAS invasion triggers ROS production through Rac1 activation and generated ROS induced mitochondrial dysfunction leading to cellular apoptosis.

  10. Invasive plant species alters consumer behavior by providing refuge from predation.

    Science.gov (United States)

    Dutra, Humberto P; Barnett, Kirk; Reinhardt, Jason R; Marquis, Robert J; Orrock, John L

    2011-07-01

    Understanding the effects of invasive plants on native consumers is important because consumer-mediated indirect effects have the potential to alter the dynamics of coexistence in native communities. Invasive plants may promote changes in consumer pressure due to changes in protective cover (i.e., the architectural complexity of the invaded habitat) and in food availability (i.e., subsidies of fruits and seeds). No experimental studies have evaluated the relative interplay of these two effects. In a factorial experiment, we manipulated cover and food provided by the invasive shrub Amur honeysuckle (Lonicera maackii) to evaluate whether this plant alters the foraging activity of native mammals. Using tracking plates to quantify mammalian foraging activity, we found that removal of honeysuckle cover, rather than changes in the fruit resources it provides, reduced the activity of important seed consumers, mice in the genus Peromyscus. Two mesopredators, Procyon lotor and Didelphis virginiana, were also affected. Moreover, we found rodents used L. maackii for cover only on cloudless nights, indicating that the effect of honeysuckle was weather-dependent. Our work provides experimental evidence that this invasive plant species changes habitat characteristics, and in so doing alters the behavior of small- and medium-sized mammals. Changes in seed predator behavior may lead to cascading effects on the seeds that mice consume.

  11. Invasive plants as potential food resource for native pollinators: A case study with two invasive species and a generalist bumble bee.

    Science.gov (United States)

    Drossart, Maxime; Michez, Denis; Vanderplanck, Maryse

    2017-11-24

    It is now well established that invasive plants may induce drifts in the quantity and/or quality of floral resources. They are then often pointed out as a potential driver of bee decline. However, their impact on bee population remains quite unclear and still controversial, as bee responses are highly variable among species. Here, we compared the amino acid composition of pollen from three native and two invasive plant species included in diets of common pollinators in NW Europe. Moreover, the nutritional intake (i.e., pollen and amino acid intakes) of Bombus terrestris colonies and the pollen foraging behaviour of workers (i.e., visiting rate, number of foraging trips, weight of pollen loads) were considered. We found significant differences in pollen nutrients among the studied species according to the plant invasive behaviour. We also found significant differences in pollen foraging behaviour according to the plant species, from few to several foraging trips carrying small or large pollen loads. Such behavioural differences directly impacted the pollen intake but depended more likely on plant morphology rather than on plant invasive behaviour. These results suggest that common generalist bumble bees might not always suffer from plant invasions, depending on their behavioural plasticity and nutritional requirements.

  12. Invasive ecosystem engineer selects for different phenotypes of an associated native species.

    Science.gov (United States)

    Wright, Jeffrey T; Gribben, Paul E; Byers, James E; Monro, Keyne

    2012-06-01

    Invasive habitat-forming ecosystem engineers modify the abiotic environment and thus represent a major perturbation to many ecosystems. Because native species often persist in these invaded habitats but have no shared history with the ecosystem engineer, the engineer may impose novel selective pressure on native species. In this study, we used a phenotypic selection framework to determine whether an invasive habitat-forming ecosystem engineer (the seaweed Caulerpa taxifolia) selects for different phenotypes of a common co-occurring native species (the bivalve Anadara trapezia). Compared to unvegetated habitat, Caulerpa habitat has lower water flow, lower dissolved oxygen, and sediments are more silty and anoxic. We determined the performance consequences of variation in key functional traits that may be affected by these abiotic changes (shell morphology, gill mass, and palp mass) for Anadara transplanted into Caulerpa and unvegetated habitat. Both linear and nonlinear performance gradients in Anadara differed between habitats, and these gradients were stronger in Caulerpa compared to unvegetated sediment. Moreover, in Caulerpa alternate phenotypes performed well, and these phenotypes were different from the dominant phenotype in unvegetated sediment. By demonstrating that phenotype-performance gradients differ between habitats, we have highlighted a role for Caulerpa as an agent of selection on native species.

  13. Shrubs as ecosystem engineers across an environmental gradient: effects on species richness and exotic plant invasion.

    Science.gov (United States)

    Kleinhesselink, Andrew R; Magnoli, Susan M; Cushman, J Hall

    2014-08-01

    Ecosystem-engineering plants modify the physical environment and can increase species diversity and exotic species invasion. At the individual level, the effects of ecosystem engineers on other plants often become more positive in stressful environments. In this study, we investigated whether the community-level effects of ecosystem engineers also become stronger in more stressful environments. Using comparative and experimental approaches, we assessed the ability of a native shrub (Ericameria ericoides) to act as an ecosystem engineer across a stress gradient in a coastal dune in northern California, USA. We found increased coarse organic matter and lower wind speeds within shrub patches. Growth of a dominant invasive grass (Bromus diandrus) was facilitated both by aboveground shrub biomass and by growing in soil taken from shrub patches. Experimental removal of shrubs negatively affected species most associated with shrubs and positively affected species most often found outside of shrubs. Counter to the stress-gradient hypothesis, the effects of shrubs on the physical environment and individual plant growth did not increase across the established stress gradient at this site. At the community level, shrub patches increased beta diversity, and contained greater rarified richness and exotic plant cover than shrub-free patches. Shrub effects on rarified richness increased with environmental stress, but effects on exotic cover and beta diversity did not. Our study provides evidence for the community-level effects of shrubs as ecosystem engineers in this system, but shows that these effects do not necessarily become stronger in more stressful environments.

  14. Transcriptome analysis and comparison reveal divergence between two invasive whitefly cryptic species

    Directory of Open Access Journals (Sweden)

    Xia Jun

    2011-09-01

    Full Text Available Abstract Background Invasive species are valuable model systems for examining the evolutionary processes and molecular mechanisms associated with their specific characteristics by comparison with closely related species. Over the past 20 years, two species of the whitefly Bemisia tabaci species complex, Middle East-Asia Minor 1 (MEAM1 and Mediterranean (MED, have both spread from their origin Middle East/Mediterranean to many countries despite their apparent differences in many life history parameters. Previously, we have sequenced the transcriptome of MED. In this study, we sequenced the transcriptome of MEAM1 and took a comparative genomic approach to investigate the transcriptome evolution and the genetic factors underlying the differences between MEAM1 and MED. Results Using Illumina sequencing technology, we generated 17 million sequencing reads for MEAM1. These reads were assembled into 57,741 unique sequences and 15,922 sequences were annotated with an E-value above 10-5. Compared with the MED transcriptome, we identified 3,585 pairs of high quality orthologous genes and inferred their sequence divergences. The average differences in coding, 5' untranslated and 3' untranslated region were 0.83%, 1.66% and 1.43%, respectively. The level of sequence divergence provides additional support to the proposition that MEAM1 and MED are two species. Based on the ratio of nonsynonymous and synonymous substitutions, we identified 24 sequences that have evolved in response to positive selection. Many of those genes are predicted to be involved in metabolism and insecticide resistance which might contribute to the divergence of the two whitefly species. Conclusions Our data present a comprehensive sequence comparison between the two invasive whitefly species. This study will provide a road map for future investigations on the molecular mechanisms underlying their biological differences.

  15. An eDNA Assay to Monitor a Globally Invasive Fish Species from Flowing Freshwater.

    Science.gov (United States)

    Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia

    2016-01-01

    Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sensitive. Consequently, populations are usually detected only when they have reached high densities and when management or containment efforts are futile. To improve monitoring, we developed an assay based on the detection of DNA traces (environmental DNA, or eDNA) of Ponto-Caspian gobies in river water. The assay specifically detects invasive goby DNA and does not react to any native fish species. We apply the assay to environmental samples and demonstrate that parameters such as sampling depth, sampling location, extraction protocol, PCR protocol and PCR inhibition greatly impact detection. We further successfully outline the invasion front of Ponto-Caspian gobies in a large river, the High Rhine in Switzerland, and thus demonstrate the applicability of the assay to lotic environments. The eDNA assay requires less time, equipment, manpower, skills, and financial resources than the conventional monitoring methods such as electrofishing, angling or diving. Samples can be taken by untrained individuals, and the assay can be performed by any molecular biologist on a conventional PCR machine. Therefore, this assay enables environment managers to map invaded areas independently of fishermen's' reports and fish community monitorings.

  16. Dispersal and selection mediate hybridization between a native and invasive species

    Science.gov (United States)

    Kovach, Ryan P.; Muhlfeld, Clint C.; Boyer, Matthew C.; Lowe, Winsor H.; Allendorf, Fred W.; Luikart, Gordon

    2015-01-01

    Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In two populations inhabiting contrasting environments, non-native admixture increased rapidly from 1984 to 2007 and was driven by surprisingly consistent processes. Individual admixture was related to two phenotypic traits associated with fitness: size at spawning and age of juvenile emigration. Fish with higher non-native admixture were larger and tended to emigrate at a younger age—relationships that are expected to confer fitness advantages to hybrid individuals. However, strong selection against non-native admixture was evident across streams and cohorts (mean selection coefficient against genotypes with non-native alleles (s) ¼ 0.60; s.e. ¼ 0.10). Nevertheless, hybridization was promoted in both streams by the continuous immigration of individuals with high levels of non-native admixture from other hybrid source populations. Thus, antagonistic relationships between dispersal and selection are mediating invasive hybridization between these fish, emphasizing that data on dispersal and natural selection are needed to fully understand the dynamics of introgression between native and non-native species. .

  17. Teaching citizen science skills online: Implications for invasive species training programs

    Science.gov (United States)

    Newman, G.; Crall, A.; Laituri, M.; Graham, J.; Stohlgren, T.; Moore, J.C.; Kodrich, K.; Holfelder, K.A.

    2010-01-01

    Citizen science programs are emerging as an efficient way to increase data collection and help monitor invasive species. Effective invasive species monitoring requires rigid data quality assurances if expensive control efforts are to be guided by volunteer data. To achieve data quality, effective online training is needed to improve field skills and reach large numbers of remote sentinel volunteers critical to early detection and rapid response. The authors evaluated the effectiveness of online static and multimedia tutorials to teach citizen science volunteers (n = 54) how to identify invasive plants; establish monitoring plots; measure percent cover; and use Global Positioning System (GPS) units. Participants trained using static and multimedia tutorials provided less (p plant cover estimates between static (??10%) and multimedia (??13%) participants did not differ (p =.86 and.08, respectively) from those of professionals (??9%). Trained volunteers struggled with plot setup and GPS skills. Overall, the online approach used did not influence conferred field skills and abilities. Traditional or multimedia online training augmented with more rigorous, repeated, and hands-on, in-person training in specialized skills required for more difficult tasks will likely improve volunteer abilities, data quality, and overall program effectiveness. ?? Taylor & Francis Group, LLC.

  18. Comparing climate change and species invasions as drivers of coldwater fish population extirpations.

    Directory of Open Access Journals (Sweden)

    Sapna Sharma

    Full Text Available Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax on cisco (Coregonus artedii population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.

  19. Predicting climate change impacts on native and invasive tree species using radial growth and twenty-first century climate scenarios

    NARCIS (Netherlands)

    González-Muñoz, N.; Linares, J.C.; Castro-Díez, P.; Sass-Klaassen, U.G.W.

    2014-01-01

    The climatic conditions predicted for the twenty-first century may aggravate the extent and impacts of plant invasions, by favouring those invaders more adapted to altered conditions or by hampering the native flora. We aim to predict the fate of native and invasive tree species in the oak forests

  20. Testing Carea varipes and Neostauropus alternus as biological control agents for the Florida invasive plant species Rhodomyrtus tomentosa.

    Science.gov (United States)

    Rhodomyrtus tomentosa (RT) a native plant to Southeastern Asia, commonly known as downy rose myrtle, is invasive to the regions of Central and South Florida. Introduced in the early 1920’s, this weed is currently considered a Category I invasive species by the Florida Exotic Pest Plant Council. RT...

  1. Environmental risk assessment for invasive alien species : A case study of apple snails affecting ecosystem services in Europe

    NARCIS (Netherlands)

    Gilioli, Gianni; Schrader, Gritta; Carlsson, Nils; van Donk, Ellen; van Leeuwen, Casper H.A.; Martín, Pablo R.; Pasquali, Sara; Vilà, Montserrat; Vos, Sybren

    2017-01-01

    The assessment of the risk posed by invasive alien species (IAS) to the environment is a component of increasing importance for Pest Risk Analysis. Standardized and comprehensive procedures to assess their impacts on ecosystem services have been developed only recently. The invasive apple snails

  2. Environmental risk assessment for invasive alien species: A case study of apple snails affecting ecosystem services in Europe

    NARCIS (Netherlands)

    Gilioli, Gianni; Schrader, Gritta; Carlsson, Nils; van Donk, Ellen; van Leeuwen, Casper H.A.; Martín, Pablo R.; Pasquali, Sara; Vilà, Montserrat; Vos, Sybren

    Abstract The assessment of the risk posed by invasive alien species (IAS) to the environment is a component of increasing importance for Pest Risk Analysis. Standardized and comprehensive procedures to assess their impacts on ecosystem services have been developed only recently. The invasive apple

  3. The ecological niche and reciprocal prediction of the disjunct distribution of an invasive species: the example of Ailanthus altissima

    Science.gov (United States)

    Thomas P. Albright; Hao Chen; Lijun Chen; Qinfeng Guo

    2010-01-01

    Knowledge of the ecological niches of invasive species in native and introduced ranges can inform management as well as ecological and evolutionary theory. Here, we identified and compared factors associated with the distribution of an invasive tree, Ailanthus altissima, in both its native Chinese and introduced US ranges and predicted potential US...

  4. Disruption of ecosystem processes in western North America by invasive species

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Dukes

    2004-09-01

    Full Text Available Many ecosystems of western North America have been dramatically changed by non-native species. Here, we review ecological impacts of 56 plant, animal, fungus, and protist species that were brought to this region by humans. We discuss characteristics of invasive species that can lead to major ecosystem impacts, and explore how invasive species alter many different attributes of ecosystems. Specifically, we include examples of invasive species that affect geomorphology, fire regimes, hydrology, microclimate, atmospheric composition, nutrient cycling, and productivity. Finally, we review the direct consequences of biological invasions for some native species. We summarize examples from this paper in Appendix 1. Our examples illustrate how, as invasive species have become dominant across large areas of western North America's grassland, shrubland, dune, riparian, and estuarine ecosystems, the properties and functioning of these systems have changed. To date, some systems in this region, such as its forests, remain relatively unaffected by invasive species. However, recent attacks of forest pathogens highlight the potential vulnerability of these ecosystemsMuchos ecosistemas de Norteamérica occidental han cambiado dramáticamente a causa del efecto producido por especies no autóctonas. Aquí se muestra una revisión del impacto ecológico producido por 56 especies diferentes de plantas, animales y hongos, y especies de protistas que fueron traídos a esta región por humanos. Discutimos las características de las especies invasoras que pueden producir un gran impacto en el ecosistema, y exploramos cómo las especies invasoras pueden alterar de forma muy diferente los atributos de un ecosistema. Específicamente, incluimos ejemplos de especies invasoras que afectan a la geomorfología, a los regímenes del fuego, a la hidrología, al microclima, a la composición atmosférica, al ciclo de nutrientes, y a la productividad. Finalmente, revisamos las

  5. The role of CVS (and FIA) data and genetic tests in assessing species vulnerability to invasive pests and changing climate

    Science.gov (United States)

    R.A. Sniezko; H.E. Lintz

    2017-01-01

    United States tree species and their associated ecosystems, managed forests, and urban plantings are increasingly vulnerable to non-native invasive pathogens and insects as well as effects associated with a changing climate. Some species, such as whitebark pine (Pinus albicaulis), have been proposed for listing under the Endangered Species Act. To...

  6. The economics of landscape restoration: Benefits of controlling bush encroachment and invasive plant species in South Africa and Namibia

    CSIR Research Space (South Africa)

    Stafford, William

    2017-01-01

    Full Text Available Bush encroachment and alien plant invasions alter the composition and/or balance of species in natural ecosystems and impact biodiversity, land productivity and water availability. Therefore, the appropriate control and management of bush...

  7. Conjugated action of two species-specific invasion proteins for fetoplacental listeriosis.

    Science.gov (United States)

    Disson, Olivier; Grayo, Solène; Huillet, Eugénie; Nikitas, Georgios; Langa-Vives, Francina; Dussurget, Olivier; Ragon, Marie; Le Monnier, Alban; Babinet, Charles; Cossart, Pascale; Lecuit, Marc

    2008-10-23

    The ability to cross host barriers is an essential virulence determinant of invasive microbial pathogens. Listeria monocytogenes is a model microorganism that crosses human intestinal and placental barriers, and causes severe maternofetal infections by an unknown mechanism. Several studies have helped to characterize the bacterial invasion proteins InlA and InlB. However, their respective species specificity has complicated investigations on their in vivo role. Here we describe two novel and complementary animal models for human listeriosis: the gerbil, a natural host for L. monocytogenes, and a knock-in mouse line ubiquitously expressing humanized E-cadherin. Using these two models, we uncover the essential and interdependent roles of InlA and InlB in fetoplacental listeriosis, and thereby decipher the molecular mechanism underlying the ability of a microbe to target and cross the placental barrier.

  8. Can a native rodent species limit the invasive potential of a non-native rodent species in tropical agroforest habitats?

    Science.gov (United States)

    Stuart, Alexander M; Prescott, Colin V; Singleton, Grant R

    2016-06-01

    Little is known about native and non-native rodent species interactions in complex tropical agroecosystems. We hypothesised that the native non-pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat, and assessed over 6 months the response of R. tanezumi and other rodent species. Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas R. everetti selected microhabitat with a dense canopy. Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, while the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non-target impacts of short-term rodent pest control. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  9. MANAGEMENT OF THE WHITE-CLAWED CRAYFISH (AUSTROPOTAMOBIUS PALLIPES IN WESTERN FRANCE: ABIOTIC AND BIOTIC FACTORS STUDY

    Directory of Open Access Journals (Sweden)

    TROUILHE M. C.

    2003-04-01

    Full Text Available In France, the distribution of the white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858, is restricted, fragmented and mainly located in headwaters. To preserve this indigenous species, it is necessary to characterize its ecological requirements (water and habitat quality. With this aim in view, a two-year study is being conducted in the Deux-Sèvres department (Western France since November 2002. Nine brooks from four different catchments are monitored regularly; eight of the nine brooks harbour whiteclawed crayfish populations. Two sampling sites are surveyed per brook, the first being where the crayfish population is located and the second 2 to 3 km downstream. Physicochemical parameters (18 are measured twice monthly and biotic factors are estimated twice yearly. In this study, the I.B.G.N. (Indice Biologique Global Normalisé protocol based on the determination of macroinvertebrates was used as a biotic index of biological water quality. Results of this preliminary study on two brooks (Thouet and Verdonnière show that physico-chemical and biological data considered separately do not provide reliable information about A. pallipes ecological requirements. However, the use of multivariate analyses (Principal Component Analysis to combine abiotic and biotic factors highlights a good correlation between these parameters. Organic matter appears to be a better discriminating factor than mineral matter affecting presence or absence of the whiteclawed crayfish.

  10. Stone crayfish in the Czech Republic: how does its population density depend on basic chemical and physical properties of water?

    Directory of Open Access Journals (Sweden)

    Vlach P.

    2013-03-01

    Full Text Available The stone crayfish (Austropotamobius torrentium Schrank is one of the two native crayfish species in the Czech Republic. The populations as well as physical and chemical parameters of water (pH, conductivity, dissolved oxygen, undissolved particles, NH3, NH4+, NO2−, NO3−, phosphorus, Ca2+ and SO42 −  of 33 streams were examined to find the ecological plasticity of this crayfish and some relations between these parameters and population densities. The mentioned parameters often significantly varied at the sites. Two approaches were applied to find relations between these parameters and observed abundance. At first, the observed streams were compared using RDA (streams  ×  physical-chemical parameters. No significance was found while testing relationship between the streams grouped along the 1st axis of model and the observed abundances of stone crayfish. However, some correlations between abundance and conductivity, calcium, nitrates and sulphates were found using polynomial regression. These relationships are explicable in terms of mutual correlations, underlying geology and other factors which affect abundances. In conclusion, A. torrentium is able to inhabit waters with a large range of physical and chemical parameters of the water without any fundamental influence on population densities. Water properties play an indisputable role as limiting ecological factors at uncommon concentrations, but population densities are probably influenced much more by the types of habitats, habitat features, predation and other ecological factors.

  11. Environmental DNA (eDNA metabarcoding assays to detect invasive invertebrate species in the Great Lakes.

    Directory of Open Access Journals (Sweden)

    Katy E Klymus

    Full Text Available Describing and monitoring biodiversity comprise integral parts of ecosystem management. Recent research coupling metabarcoding and environmental DNA (eDNA demonstrate that these methods can serve as important tools for surveying biodiversity, while significantly decreasing the time, expense and resources spent on traditional survey methods. The literature emphasizes the importance of genetic marker development, as the markers dictate the applicability, sensitivity and resolution ability of an eDNA assay. The present study developed two metabarcoding eDNA assays using the mtDNA 16S RNA gene with Illumina MiSeq platform to detect invertebrate fauna in the Laurentian Great Lakes and surrounding waterways, with a focus for use on invasive bivalve and gastropod species monitoring. We employed careful primer design and in vitro testing with mock communities to assess ability of the markers to amplify and sequence targeted species DNA, while retaining rank abundance information. In our mock communities, read abundances reflected the initial input abundance, with regressions having significant slopes (p<0.05 and high coefficients of determination (R2 for all comparisons. Tests on field environmental samples revealed similar ability of our markers to measure relative abundance. Due to the limited reference sequence data available for these invertebrate species, care must be taken when analyzing results and identifying sequence reads to species level. These markers extend eDNA metabarcoding research for molluscs and appear relevant to other invertebrate taxa, such as rotifers and bryozoans. Furthermore, the sphaeriid mussel assay is group-specific, exclusively amplifying bivalves in the Sphaeridae family and providing species-level identification. Our assays provide useful tools for managers and conservation scientists, facilitating early detection of invasive species as well as improving resolution of mollusc diversity.

  12. Citizen science contributes to our knowledge of invasive plant species distributions

    Science.gov (United States)

    Crall, Alycia W.; Jarnevich, Catherine S.; Young, Nicholas E.; Panke, Brendon; Renz, Mark; Stohlgren, Thomas

    2015-01-01

    Citizen science is commonly cited as an effective approach to expand the scale of invasive species data collection and monitoring. However, researchers often hesitate to use these data due to concerns over data quality. In light of recent research on the quality of data collected by volunteers, we aimed to demonstrate the extent to which citizen science data can increase sampling coverage, fill gaps in species distributions, and improve habitat suitability models compared to professionally generated data sets used in isolation. We combined data sets from professionals and volunteers for five invasive plant species (Alliaria petiolata, Berberis thunbergii, Cirsium palustre, Pastinaca sativa, Polygonum cuspidatum) in portions of Wisconsin. Volunteers sampled counties not sampled by professionals for three of the five species. Volunteers also added presence locations within counties not included in professional data sets, especially in southern portions of the state where professional monitoring activities had been minimal. Volunteers made a significant contribution to the known distribution, environmental gradients sampled, and the habitat suitability of P. cuspidatum. Models generated with professional data sets for the other four species performed reasonably well according to AUC values (>0.76). The addition of volunteer data did not greatly change model performance (AUC > 0.79) but did change the suitability surface generated by the models, making them more realistic. Our findings underscore the need to merge data from multiple sources to improve knowledge of current species distributions, and to predict their movement under present and future environmental conditions. The efficiency and success of these approaches require that monitoring efforts involve multiple stakeholders in continuous collaboration via established monitoring networks.

  13. Potential problems of removing one invasive species at a time: a meta-analysis of the interactions between invasive vertebrates and unexpected effects of removal programs

    Directory of Open Access Journals (Sweden)

    Sebastián A. Ballari

    2016-06-01

    Full Text Available Although the co-occurrence of nonnative vertebrates is a ubiquitous global phenomenon, the study of interactions between invaders is poorly represented in the literature. Limited understanding of the interactions between co-occurring vertebrates can be problematic for predicting how the removal of only one invasive—a common management scenario—will affect native communities. We suggest a trophic food web framework for predicting the effects of single-species management on native biodiversity. We used a literature search and meta-analysis to assess current understanding of how the removal of one invasive vertebrate affects native biodiversity relative to when two invasives are present. The majority of studies focused on the removal of carnivores, mainly within aquatic systems, which highlights a critical knowledge gap in our understanding of co-occurring invasive vertebrates. We found that removal of one invasive vertebrate caused a significant negative effect on native species compared to when two invasive vertebrates were present. These unexpected results could arise because of the positioning and hierarchy of the co-occurring invasives in the food web (e.g., carnivore–carnivore or carnivore–herbivore. We consider that there are important knowledge gaps to determinate the effects of multiple co-existing invaders on native ecosystems, and this information could be precious for management.

  14. The Invasive Species Forecasting System (ISFS): An iRODS-Based, Cloud-Enabled Decision Support System for Invasive Species Habitat Suitability Modeling

    Science.gov (United States)

    Gill, Roger; Schnase, John L.

    2012-01-01

    The Invasive Species Forecasting System (ISFS) is an online decision support system that allows users to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of interest, such as a national park, monument, forest, or refuge. Target customers for ISFS are natural resource managers and decision makers who have a need for scientifically valid, model- based predictions of the habitat suitability of plant species of management concern. In a joint project involving NASA and the Maryland Department of Natural Resources, ISFS has been used to model the potential distribution of Wavyleaf Basketgrass in Maryland's Chesapeake Bay Watershed. Maximum entropy techniques are used to generate predictive maps using predictor datasets derived from remotely sensed data and climate simulation outputs. The workflow to run a model is implemented in an iRODS microservice using a custom ISFS file driver that clips and re-projects data to geographic regions of interest, then shells out to perform MaxEnt processing on the input data. When the model completes, all output files and maps from the model run are registered in iRODS and made accessible to the user. The ISFS user interface is a web browser that uses the iRODS PHP client to interact with the ISFS/iRODS- server. ISFS is designed to reside in a VMware virtual machine running SLES 11 and iRODS 3.0. The ISFS virtual machine is hosted in a VMware vSphere private cloud infrastructure to deliver the online service.

  15. Stress reaction in crayfish: chlorides help to withstand stress in high nitrite concentration conditions – preliminary study

    Directory of Open Access Journals (Sweden)

    Kozák P.

    2011-06-01

    Full Text Available A non-invasive method of recording cardiac activity (heart rate – HR and stress reaction (stress index – SI was used to understand the immediate and ongoing stress reaction of crayfish to the chemical stimuli. This method detects changes in the shape and amplitude parameters of the response to the stress factors, which characterized the crayfish functional state. Experimental animals (Astacus leptodactylus were divided to the two groups with (400 mg·L-1 Cl− and without added chlorides and then exposed to a stepwise increased level of nitrite to the final (sublethal-lethal concentration of 60 mg·L-1 N-NO\\hbox{$_{2}^{-}$}−2 within 24 hours. The course of crayfish reaction was evident and provided information about their reaction to the sublethal-lethal concentration over time. As expected, a less prominent stress reaction was detected in the group with chlorides. The non-invasive method successfully evaluated the sensing of chemical stimuli in water through HR and SI changes.

  16. Chronic impacts of invasive herbivores on a foundational forest species: a whole-tree perspective.

    Science.gov (United States)

    Wilson, Claire M; Schaeffer, Robert N; Hickin, Mauri L; Rigsby, Chad M; Sommi, Amanda F; Thornber, Carol S; Orians, Colin M; Preisser, Evan L

    2018-05-05

    Forests make up a large portion of terrestrial plant biomass, and the long-lived woody plants that dominate them possess an array of traits that deter consumption by forest pests. Although often extremely effective against native consumers, invasive species that avoid or overcome these defenses can wreak havoc on trees and surrounding ecosystems. This is especially true when multiple invasive species co-occur, since interactions between invasive herbivores may yield non-additive effects on the host. While the threat posed by invasive forest pests is well known, long-term field experiments are necessary to explore these consumer-host interactions at appropriate spatial and temporal scales. Moreover, it is important to measure multiple variables to get a 'whole-plant' picture of their combined impact. We report the results of a four-year field experiment addressing the individual and combined impacts of two invasive herbivores, the hemlock woolly adelgid (Adelges tsugae) and elongate hemlock scale (Fiorinia externa), on native eastern hemlock (Tsuga canadensis) in southern New England. In 2011, we planted 200 hemlock saplings into a temperate forest understory and experimentally manipulated the presence/absence of both herbivore species; in 2015, we harvested the 88 remaining saplings and assessed plant physiology, growth, and resource allocation. Adelgids strongly affected hemlock growth: infested saplings had lower above/belowground biomass ratios, more needle loss, and produced fewer new needles than control saplings. Hemlock scale did not alter plant biomass allocation or growth, and its co-occurrence did not alter the impact of adelgid. While both adelgid and scale impacted the concentrations of primary metabolites, adelgid effects were more pronounced. Adelgid feeding simultaneously increased free amino acids local to feeding sites and a ~30% reduction in starch. The cumulative impact of adelgid-induced needle loss, manipulation of nitrogen pools, and the loss

  17. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.).

    Science.gov (United States)

    Yang, Ruyi; Yu, Guodong; Tang, Jianjun; Chen, Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species (Solidago canadensis L.) in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels (control, 300, and 600 mg/kg soil) were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhi