The Experts below are selected from a list of 1032 Experts worldwide ranked by ideXlab platform
Michael Dobson - One of the best experts on this subject based on the ideXlab platform.
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Stream ecosystems respond to riparian invasion by Japanese knotweed (Fallopia Japonica)
Canadian Journal of Fisheries and Aquatic Sciences, 2007Co-Authors: Antoine Lecerf, Denise Patfield, Anatole Boiché, Miira P. Riipinen, Eric Chauvet, Michael DobsonAbstract:There are growing concerns about the rapid spread of exotic plants into riparian zones, yet little information is currently available on their influence on stream ecosystems. This study assessed the impact of riparian invasion by Japa- nese knotweed (Fallopia Japonica), an aggressive invader, on leaf litter breakdown and its associated biota (aquatic hyphomycete fungi and benthic invertebrates) in heterotrophic, low-order streams in The Pennines (England) and the Pyre- nees (France). Our results suggest that leaf consumers (aquatic hyphomycetes and invertebrate shredders) can readily use knotweed leaf litter even in stream sites where it was not previously present. However, aquatic hyphomycete and inverte- brate assemblages differed between stream sites with and without knotweed. Leaf litter breakdown rate and relative abun- dance of large invertebrate shredders (mainly Trichoptera) were enhanced in the Pyrenean invaded site, whose channel contained a high proportion of knotweed leaf litter, whereas no such effects were observed in The Pennines, possibly be- cause of the less extensive knotweed invasion. Alteration of riparian vegetation by plant invaders could therefore increas- ingly influence instream community and ecological functions as the severity of invasion rises. Resume : En depit des preoccupations majeures posees par la proliferation rapide de plantes exotiques dans les zones riveraines, il existe actuellement peu de donnees concernant les consequences ecologiques sur les cours d'eau. Dans cette etude, nous avons evalue l'effet de la renouee du Japon (Fallopia Japonica), une plante eminemment envahissante, sur la decomposition des feuilles et les organismes biologiques associes (hyphomycetes aquatiques et invertebres ben- thiques) dans des petits cours d'eau heterotrophes de la region des Pennines (Angleterre) et des Pyrenees (France). Nos resultats suggerent que les consommateurs de feuilles (hyphomycetes aquatiques et invertebres dechiqueteurs) peuvent aisement utiliser la litiere de renouee, meme au sein des troncons de cours d'eau ou elle n'etait pas presente aupara- vant. Cependant, les assemblages d'hyphomycetes aquatiques et d'invertebres different entre les troncons de cours d'eau avec et sans renouee du Japon. La vitesse de decomposition des litieres et l'abondance relative des invertebres dechiqueteurs de grande taille (principalement les Trichopteres) ont augmente au niveau du site pyreneen envahi ou do- mine la litiere de renouee. Ces resultats ne s'observent pas sur le site envahi des Pennines, peut-etre en raison de la moindre ampleur de l'invasion par la renouee. Ainsi l'impact des plantes exotiques sur la structure et les fonctions eco- logiques des communautes aquatiques pourrait etre en rapport avec l'intensite de l'invasion.
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Stream ecosystems respond to riparian invasion by Japanese knotweed (Fallopia Japonica)
Canadian Journal of Fisheries and Aquatic Sciences, 2007Co-Authors: Antoine Lecerf, Denise Patfield, Anatole Boiché, Miira P. Riipinen, Eric Chauvet, Michael DobsonAbstract:There are growing concerns about the rapid spread of exotic plants into riparian zones, yet little information is currently available on their influence on stream ecosystems. This study assessed the impact of riparian invasion by Japa- nese knotweed (Fallopia Japonica), an aggressive invader, on leaf litter breakdown and its associated biota (aquatic hyphomycete fungi and benthic invertebrates) in heterotrophic, low-order streams in The Pennines (England) and the Pyre- nees (France). Our results suggest that leaf consumers (aquatic hyphomycetes and invertebrate shredders) can readily use knotweed leaf litter even in stream sites where it was not previously present. However, aquatic hyphomycete and inverte- brate assemblages differed between stream sites with and without knotweed. Leaf litter breakdown rate and relative abun- dance of large invertebrate shredders (mainly Trichoptera) were enhanced in the Pyrenean invaded site, whose channel contained a high proportion of knotweed leaf litter, whereas no such effects were observed in The Pennines, possibly be- cause of the less extensive knotweed invasion. Alteration of riparian vegetation by plant invaders could therefore increas- ingly influence instream community and ecological functions as the severity of invasion rises.
John P Bailey - One of the best experts on this subject based on the ideXlab platform.
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evidence for massive clonal growth in the invasive weed Fallopia Japonica japanese knotweed
Botanical Journal of the Linnean Society, 2000Co-Authors: Michelle L Hollingsworth, John P BaileyAbstract:Abstract Clonal growth in introduced populations of Japanese Knotweed ( Fallopia Japonica ) in Britain was assessed using RAPDs (Randomly Amplified Polymorphic DNA). A total of 150 British samples was analysed for genetic variation using ten arbitrary decamer primers, and compared with data from 16 samples of other introduced populations from Europe and the U.S.A. All samples produced an identical multi-primer RAPD profile. Accepting that RAPD profile identity need not equate to genet identity, based on the sensitivity of these markers for detecting genetic diversity in related taxa and on the absence of male fertile individuals of this species in Britain, we interpret this result as consistent with the presence of a single, exceptionally widespread clone. This clone must represent one of the world's largest vascular plants.
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Regular ArticleEvidence for massive clonal growth in the invasive weed Fallopia Japonica (Japanese Knotweed)
Botanical Journal of the Linnean Society, 2000Co-Authors: Michelle L Hollingsworth, John P BaileyAbstract:Clonal growth in introduced populations of Japanese Knotweed (Fallopia Japonica) in Britain was assessed using RAPDs (Randomly Amplified Polymorphic DNA). A total of 150 British samples was analysed for genetic variation using ten arbitrary decamer primers, and compared with data from 16 samples of other introduced populations from Europe and the U.S.A. All samples produced an identical multi-primer RAPD profile. Accepting that RAPD profile identity need not equate to genet identity, based on the sensitivity of these markers for detecting genetic diversity in related taxa and on the absence of male fertile individuals of this species in Britain, we interpret this result as consistent with the presence of a single, exceptionally widespread clone. This clone must represent one of the world's largest vascular plants.
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Climate and the distribution of Fallopia Japonica: use of an introduced species to test the predictive capacity of response surfaces
Journal of Vegetation Science, 1995Co-Authors: David J. Beerling, Brian Huntley, John P BaileyAbstract:Abstract. The relationship between present climate and the distribution in Europe of the aggressively invasive exotic Fallopia Japonica is described by fitting a response surface based on three bioclimatic variables: mean temperature of the coldest month, the annual temperature sum > 5 °C, and the ratio of actual to potential evapotranspiration. The close fit between the observed and simulated distributions suggests that the species' European distribution is climatically determined. The response surface also provides a simulation of the extent of the area of native distribution of F. Japonica in Southeast Asia that is generally accurate, confirming the robustness of the static correlative model upon which it is based. Simulations of the potential distribution of F. Japonica under two alternative 2 x CO2 climate change scenarios indicate the likelihood of considerable spread into higher latitudes and possible eventual exclusion of the species from central Europe. However, despite the robustness of the response surface with present-day climate, the reliability of these simulations as forecasts is likely to be limited because no account is taken of the direct effects of CO2 and their interaction with the species' physiological responses to climate. Similarly, no account is taken of the potential impact of interactions with ‘new’ species as ecosystems change in composition in response to climate change. Nevertheless, the simulations indicate both the possible magnitude of the impacts of forecast climate changes and the regions that may be susceptible to invasion by F. Japonica.
David J. Beerling - One of the best experts on this subject based on the ideXlab platform.
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Climate and the distribution of Fallopia Japonica: use of an introduced species to test the predictive capacity of response surfaces
Journal of Vegetation Science, 1995Co-Authors: David J. Beerling, Brian Huntley, John P BaileyAbstract:Abstract. The relationship between present climate and the distribution in Europe of the aggressively invasive exotic Fallopia Japonica is described by fitting a response surface based on three bioclimatic variables: mean temperature of the coldest month, the annual temperature sum > 5 °C, and the ratio of actual to potential evapotranspiration. The close fit between the observed and simulated distributions suggests that the species' European distribution is climatically determined. The response surface also provides a simulation of the extent of the area of native distribution of F. Japonica in Southeast Asia that is generally accurate, confirming the robustness of the static correlative model upon which it is based. Simulations of the potential distribution of F. Japonica under two alternative 2 x CO2 climate change scenarios indicate the likelihood of considerable spread into higher latitudes and possible eventual exclusion of the species from central Europe. However, despite the robustness of the response surface with present-day climate, the reliability of these simulations as forecasts is likely to be limited because no account is taken of the direct effects of CO2 and their interaction with the species' physiological responses to climate. Similarly, no account is taken of the potential impact of interactions with ‘new’ species as ecosystems change in composition in response to climate change. Nevertheless, the simulations indicate both the possible magnitude of the impacts of forecast climate changes and the regions that may be susceptible to invasion by F. Japonica.
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the impact of temperature on the northern distribution limits of the introduced species Fallopia Japonica and impatiens glandulifera in north west europe
Journal of Biogeography, 1993Co-Authors: David J. BeerlingAbstract:This paper tests the predictions of sensitivity ana- lysis performed on two matrix population growth models, for annual and perennial vegetation (Woodward, 1988). Climatic correlations have been established for two intro- duced invasive plant species Fallopia Japonica (Japanese knotweed) and Impatiens glandulifera (Himalayan balsam) in north-west Europe. These two species represent exam- ples of perennial and annual vegetation respectively. In accordance with the model predictions, the northern distri- bution limit of F. Japonica was found to be controlled by two climatic variables-the length of the growing season, measured in day-degrees, and the minimum temperature- while for I. glandulifera only the length of the growing season was critical. Experimental verification of the results is crucial for understanding the mechanisms operating to limit plant distributions. By use of the predictions established by the climatic cor- relations for I. glandulifera and F. Japonica, maps have been produced forecasting the potential northward spread of both species on the basis of a 1.5?C and a 4.5?C rise in global mean surface air-temperature. These temperatures represent the minimum and maximum increases predicted to occur by general circulation models for a doubling of CO2 concentration in the atmosphere. For a global tempera- ture increase of 1.5?C the maps demonstrate a maximum northward spread of F. Japonica from a latitude of 63? to 68?N and for I. glandulifera from 64? up to 69?N. The greater temperature increase of 4.5?C indicates a consider- able potential for expansion in the range of F. Japonica in Norway and Sweden but a distribution which was restricted along the eastern coast of Sweden and southern Finland. In contrast, I. glandulifera could colonize the whole of the Fennoscandinavian area. The predictions are made assum- ing no migrational lag and no soil 'incompatibility'. Geo- graphical differences in the patterns of spread between the species were explained with reference to the different factors affecting perennial and annual vegetation.
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The impact of temperature on the northern distribution limits of the introduced species Fallopia Japonica and Impatiens glandulifera in north-west Europe
Journal of Biogeography, 1993Co-Authors: David J. BeerlingAbstract:This paper tests the predictions of sensitivity ana- lysis performed on two matrix population growth models, for annual and perennial vegetation (Woodward, 1988). Climatic correlations have been established for two intro- duced invasive plant species Fallopia Japonica (Japanese knotweed) and Impatiens glandulifera (Himalayan balsam) in north-west Europe. These two species represent exam- ples of perennial and annual vegetation respectively. In accordance with the model predictions, the northern distri- bution limit of F. Japonica was found to be controlled by two climatic variables-the length of the growing season, measured in day-degrees, and the minimum temperature- while for I. glandulifera only the length of the growing season was critical. Experimental verification of the results is crucial for understanding the mechanisms operating to limit plant distributions. By use of the predictions established by the climatic cor- relations for I. glandulifera and F. Japonica, maps have been produced forecasting the potential northward spread of both species on the basis of a 1.5?C and a 4.5?C rise in global mean surface air-temperature. These temperatures represent the minimum and maximum increases predicted to occur by general circulation models for a doubling of CO2 concentration in the atmosphere. For a global tempera- ture increase of 1.5?C the maps demonstrate a maximum northward spread of F. Japonica from a latitude of 63? to 68?N and for I. glandulifera from 64? up to 69?N. The greater temperature increase of 4.5?C indicates a consider- able potential for expansion in the range of F. Japonica in Norway and Sweden but a distribution which was restricted along the eastern coast of Sweden and southern Finland. In contrast, I. glandulifera could colonize the whole of the Fennoscandinavian area. The predictions are made assum- ing no migrational lag and no soil 'incompatibility'. Geo- graphical differences in the patterns of spread between the species were explained with reference to the different factors affecting perennial and annual vegetation.
Antoine Lecerf - One of the best experts on this subject based on the ideXlab platform.
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Stream ecosystems respond to riparian invasion by Japanese knotweed (Fallopia Japonica)
Canadian Journal of Fisheries and Aquatic Sciences, 2007Co-Authors: Antoine Lecerf, Denise Patfield, Anatole Boiché, Miira P. Riipinen, Eric Chauvet, Michael DobsonAbstract:There are growing concerns about the rapid spread of exotic plants into riparian zones, yet little information is currently available on their influence on stream ecosystems. This study assessed the impact of riparian invasion by Japa- nese knotweed (Fallopia Japonica), an aggressive invader, on leaf litter breakdown and its associated biota (aquatic hyphomycete fungi and benthic invertebrates) in heterotrophic, low-order streams in The Pennines (England) and the Pyre- nees (France). Our results suggest that leaf consumers (aquatic hyphomycetes and invertebrate shredders) can readily use knotweed leaf litter even in stream sites where it was not previously present. However, aquatic hyphomycete and inverte- brate assemblages differed between stream sites with and without knotweed. Leaf litter breakdown rate and relative abun- dance of large invertebrate shredders (mainly Trichoptera) were enhanced in the Pyrenean invaded site, whose channel contained a high proportion of knotweed leaf litter, whereas no such effects were observed in The Pennines, possibly be- cause of the less extensive knotweed invasion. Alteration of riparian vegetation by plant invaders could therefore increas- ingly influence instream community and ecological functions as the severity of invasion rises. Resume : En depit des preoccupations majeures posees par la proliferation rapide de plantes exotiques dans les zones riveraines, il existe actuellement peu de donnees concernant les consequences ecologiques sur les cours d'eau. Dans cette etude, nous avons evalue l'effet de la renouee du Japon (Fallopia Japonica), une plante eminemment envahissante, sur la decomposition des feuilles et les organismes biologiques associes (hyphomycetes aquatiques et invertebres ben- thiques) dans des petits cours d'eau heterotrophes de la region des Pennines (Angleterre) et des Pyrenees (France). Nos resultats suggerent que les consommateurs de feuilles (hyphomycetes aquatiques et invertebres dechiqueteurs) peuvent aisement utiliser la litiere de renouee, meme au sein des troncons de cours d'eau ou elle n'etait pas presente aupara- vant. Cependant, les assemblages d'hyphomycetes aquatiques et d'invertebres different entre les troncons de cours d'eau avec et sans renouee du Japon. La vitesse de decomposition des litieres et l'abondance relative des invertebres dechiqueteurs de grande taille (principalement les Trichopteres) ont augmente au niveau du site pyreneen envahi ou do- mine la litiere de renouee. Ces resultats ne s'observent pas sur le site envahi des Pennines, peut-etre en raison de la moindre ampleur de l'invasion par la renouee. Ainsi l'impact des plantes exotiques sur la structure et les fonctions eco- logiques des communautes aquatiques pourrait etre en rapport avec l'intensite de l'invasion.
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Stream ecosystems respond to riparian invasion by Japanese knotweed (Fallopia Japonica)
Canadian Journal of Fisheries and Aquatic Sciences, 2007Co-Authors: Antoine Lecerf, Denise Patfield, Anatole Boiché, Miira P. Riipinen, Eric Chauvet, Michael DobsonAbstract:There are growing concerns about the rapid spread of exotic plants into riparian zones, yet little information is currently available on their influence on stream ecosystems. This study assessed the impact of riparian invasion by Japa- nese knotweed (Fallopia Japonica), an aggressive invader, on leaf litter breakdown and its associated biota (aquatic hyphomycete fungi and benthic invertebrates) in heterotrophic, low-order streams in The Pennines (England) and the Pyre- nees (France). Our results suggest that leaf consumers (aquatic hyphomycetes and invertebrate shredders) can readily use knotweed leaf litter even in stream sites where it was not previously present. However, aquatic hyphomycete and inverte- brate assemblages differed between stream sites with and without knotweed. Leaf litter breakdown rate and relative abun- dance of large invertebrate shredders (mainly Trichoptera) were enhanced in the Pyrenean invaded site, whose channel contained a high proportion of knotweed leaf litter, whereas no such effects were observed in The Pennines, possibly be- cause of the less extensive knotweed invasion. Alteration of riparian vegetation by plant invaders could therefore increas- ingly influence instream community and ecological functions as the severity of invasion rises.
David P. Matlaga - One of the best experts on this subject based on the ideXlab platform.
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Decomposition and benthic macroinvertebrate communities of exotic Japanese knotweed (Fallopia Japonica) and American sycamore (Platanus occidentalus) detritus within the Susquehanna River
Journal of Freshwater Ecology, 2018Co-Authors: Kaelyn J. Fogelman, Michael Bilger, Jack R. Holt, David P. MatlagaAbstract:The invasive shrub Japanese knotweed (Fallopia Japonica) is spreading through riparian forests in Central Pennsylvania. There is concern that detritus from this species may impact adjacent aquatic ...
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Decomposition and benthic macroinvertebrate communities of exotic Japanese knotweed (Fallopia Japonica) and American sycamore (Platanus occidentalus) detritus within the Susquehanna River
Taylor & Francis Group, 2018Co-Authors: Kaelyn J. Fogelman, Jack R. Holt, Michael D. Bilger, David P. MatlagaAbstract:The invasive shrub Japanese knotweed (Fallopia Japonica) is spreading through riparian forests in Central Pennsylvania. There is concern that detritus from this species may impact adjacent aquatic ecosystems, as allocthonous material forms the basis for aquatic food webs and may impact benthic community structure. This study compares key ecosystem processes within Japanese knotweed leaf litter to leaf litter of a native riparian species, American sycamore (Platanus occidentalis). We assess benthic macroinvertebrate communities and decomposition rates within experimental Japanese knotweed and American sycamore leaf packs at three sites within the Susquehanna River. Japanese knotweed detritus hosted a similar macroinvertebrate community to American sycamore and their assemblages had similar representation of functional feeding groups. The similarity between the invertebrate communities occupying American sycamore and Japanese knotweed detritus indicates that macroinvertebrates are able to utilize non-native litter for habitat and potentially as an energy source. American sycamore decomposed at a faster rate than Japanese knotweed, lending support to the Novel Weapons Hypothesis, which suggests that non-native species like Japanese knotweed may inhibit microbial colonization and subsequent litter breakdown. Our results suggest that invasion of Japanese knotweed along riparian corridors of large river systems may not have severe ecological consequences on local ecosystem processes
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Influence of Disturbance on Japanese Knotweed (Fallopia Japonica) Stem and Rhizome Fragment Recruitment Success within Riparian Forest Understory
Natural Areas Journal, 2016Co-Authors: Chelsea Gowton, Andrew M. Budsock, David P. MatlagaAbstract:ABSTRACT Japanese knotweed (Fallopia Japonica) is an herbaceous invader in North America and Europe with the ability to recruit via several modes (seeds, rhizome, and stem fragments). Within US riparian forests where Japanese knotweed invades, disturbances are common over space and time in the form of flooding and mowing. It remains unknown how disturbance influences the relative recruitment success of sexual and clonal propagules of this riparian invader. Using an experimental approach, we addressed this topic by planting seeds, and rhizome and stem fragments into riparian forest plots with intact Japanese knotweed subcanopies, and into plots with the Japanese knotweed subcanopy removed, simulating disturbance. We monitored canopy openness and propagule fate (shoot emergence and height) over five months. Regardless of treatment, rhizome fragments had a higher establishment probability (85%) than seeds (3%) or stem fragments (16%). Due to a small sample size, we did not analyze the effect of disturbance o...