scholarly journals Identifying Sustainable Grassland Management Approaches in Response to the Invasive Legume Lespedeza cuneata: A Functional Group Approach

2020 ◽  
Vol 12 (15) ◽  
pp. 5951
Author(s):  
Erin M. Garrett ◽  
David J. Gibson
Keyword(s):  
Species Composition ◽  
Functional Groups ◽  
Community Assembly ◽  
Mycorrhizal Fungi ◽  
Native Species ◽  
Invasive Plant ◽  
Greenhouse Experiment ◽  
Driver Model ◽  
Lespedeza Cuneata ◽  
The Impact

We propose combining the filter framework model of community assembly with the passenger-driver model of non-native species behavior to help clarify the impacts of invasive species in the communities they invade and to guide sustainable management protocols. Observational field surveys and a greenhouse experiment explored the role of the invasive legume Lespedeza cuneata in the communities it invades and how natives in three functional groups—grasses, forbs, and legumes—respond to its presence. Within-site analyses from the field survey revealed differences in invaded and uninvaded areas in half of the sites, suggesting that site-specific characteristics influences whether L. cuneata’s presence corresponds to local differences in species composition. The greenhouse experiment found higher levels of saprophytic and arbuscular mycorrhizal fungi in soil conditioned by L. cuneata than in unconditioned soil. However, competition between L. cuneata or the native congener L. capitata and nine native species illustrated stronger aboveground competitive effects than belowground soil effects due to soil conditioning, with impacts differing among functional groups. The response of L. cuneata was reduced in the presence of grasses and other legumes but not forbs. Assessing the impact of L. cuneata with the combined community assembly model revealed this invasive plant acts as a driver because it alters abiotic and biotic filters to impact species composition. Managing for high grass abundance and planting native legumes will help sustain grasslands from L. cuneata invasion.

scholarly journals Effects of High Impact Grazing on Species Diversity and Plant Functional Groups in Grasslands of Northern Argentina

2018 ◽  
Vol 10 (9) ◽  
pp. 3153
Author(s):  
Ditmar Kurtz ◽  
Marcus Giese ◽  
Folkard Asch ◽  
Saskia Windisch ◽  
María Goldfarb
Keyword(s):  
Species Composition ◽  
Functional Groups ◽  
Plant Species ◽  
High Impact ◽  
Sustainable Land Use ◽  
Plant Functional Groups ◽  
Seasonal Effects ◽  
Plant Species Composition ◽  
Wiener Diversity Index ◽  
The Impact

High impact grazing (HIG) was proposed as a management option to reduce standing dead biomass in Northern Argentinean (Chaco) rangelands. However, the effects of HIG on grassland diversity and shifts in plant functional groups are largely unknown but essential to assess the sustainability of the impact. During a two-year grazing experiment, HIG was applied every month to analyze the seasonal effects on plant species composition and plant functional groups. The results indicate that irrespective of the season in which HIG was applied, the diversity parameters were not negatively affected. Species richness, the Shannon–Wiener diversity index and the Shannon’s equitability index did not differ from the control site within a 12-month period after HIG. While plant functional groups of dicotyledonous and annual species could not benefit from the HIG disturbance, C3-, C4-monocotyledonous and perennials increased their absolute and relative green cover. Our results suggest that HIG, if not applied in shorter frequencies than a year, neither alters diversity nor shifts the plant species composition of the grassland plant community, but instead it promotes previously established rather competitive species. HIG could therefore contribute as an alternative management practice to the sustainable land use intensification of the “Gran Chaco” grassland ecosystem and even counteract the encroachment of “low value” species.

scholarly journals Cheatgrass invasion alters the abundance and composition of dark septate fungal communities in sagebrush steppe

Botany ◽  
2016 ◽  
Vol 94 (6) ◽  
pp. 481-491 ◽  
Author(s):  
Catherine A. Gehring ◽  
Michaela Hayer ◽  
Lluvia Flores-Rentería ◽  
Andrew F. Krohn ◽  
Egbert Schwartz ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Species ◽  
Mycorrhizal Fungi ◽  
Native Species ◽  
Invasive Plant ◽  
Soil Microbial Communities ◽  
Sagebrush Steppe ◽  
Native Plant ◽  
Native Plant Species ◽  
Dark Septate Fungi

Invasive, non-native plant species can alter soil microbial communities in ways that contribute to their persistence. While most studies emphasize mycorrhizal fungi, invasive plants also may influence communities of dark septate fungi (DSF), which are common root endophytes that can function like mycorrhizas. We tested the hypothesis that a widespread invasive plant in the western United States, cheatgrass (Bromus tectorum L.), influenced the abundance and community composition of DSF by examining the roots and rhizosphere soils of cheatgrass and two native plant species in cheatgrass-invaded and noninvaded areas of sagebrush steppe. We focused on cheatgrass because it is negatively affected by mycorrhizal fungi and colonized by DSF. We found that DSF root colonization and operational taxonomic unit (OTU) richness were significantly higher in sagebrush (Artemisia tridentata Nutt.) and rice grass (Achnatherum hymenoides (Roem. & Schult.) Barkworth) from invaded areas than noninvaded areas. Cheatgrass roots had similar levels of DSF colonization and OTU richness as native plants. The community composition of DSF varied with invasion in the roots and soils of native species and among the roots of the three plant species in the invaded areas. The substantial changes in DSF we observed following cheatgrass invasion argue for comparative studies of DSF function in native and non-native plant species.

Allelopathic disruptions of biotic interactions due to non-native plants.

2020 ◽  
pp. 270-280
Author(s):  
Lauren M. Smith-Ramesh
Keyword(s):  
Invasive Species ◽  
Mycorrhizal Fungi ◽  
Native Species ◽  
Invasive Plant ◽  
Native Plants ◽  
Biotic Interactions ◽  
Resident Species ◽  
Negative Impacts ◽  
And Performance ◽  
Native Invasive

Abstract Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.

Stable isotopes as early indicators of high impact after plant invasion: A remote sensing perspective

2020 ◽  
Author(s):  
André Große-Stoltenberg ◽  
Christine Hellmann ◽  
Jan Thiele ◽  
Jens Oldeland ◽  
Christiane Werner
Keyword(s):  
Remote Sensing ◽  
Stable Isotopes ◽  
Native Species ◽  
Invasive Plant ◽  
Leaf Traits ◽  
High Impact ◽  
Hyperspectral Data ◽  
Water Cycling ◽  
Leaf N Content ◽  
The Impact

<p>High impact invasive plant species, such as the N-fixing and water-spending tree <em>Acacia longifolia</em>, are a major threat to ecosystem functioning worldwide. For example, <em>Acacia'</em>s impact on nutrient and water-cycling in Mediterranean dune ecosystems is well understood. However, early detection of such impacts remains challenging. Therefore, novel approaches are required to map functional indicators of high invader impact. Here, we tested in a real world context if the stable isotopes δ<sup>13</sup>C and δ<sup>15</sup>N could be such mappable indicators. First, we show that <em>A. longifolia </em>differs regarding its biochemical leaf traits from the native species of the same growth form particularly regarding leaf N content as well as δ<sup>13</sup>C and δ<sup>15</sup>N. This may indicate a high impact on N and water cycling, and can be retrieved from hyperspectral data. Second, the impact of the invader on N cycling was mapped joining the spatial distribution of δ<sup>15</sup>N with airborne laserscanning data. Foliar δ<sup>15</sup>N of a non-fixing, native species increased in vicinity of invasive stands indicating an uptake of N previously fixed by the invader. Finally, those impacts possibly result in an increase of productivity of the whole dune ecosystem even when invader cover is low. This increase can be mapped integrating hyperspectral imagery with LiDAR data. Thus, there is potential to retrieve functional indicators of high impact including stable isotopes using remote sensing.</p>

Allelopathic disruptions of biotic interactions due to non-native plants.

2020 ◽  
pp. 270-280
Author(s):  
Lauren M. Smith-Ramesh ◽  
Keyword(s):  
Invasive Species ◽  
Mycorrhizal Fungi ◽  
Native Species ◽  
Invasive Plant ◽  
Native Plants ◽  
Biotic Interactions ◽  
Resident Species ◽  
Negative Impacts ◽  
And Performance ◽  
Native Invasive

Allelopathy, or the process by which plants influence the growth and performance of their neighbours through the release of chemicals, may play a key role in mediating the impacts of non-native invasive species on their neighbours. The Novel Weapons Hypothesis purports that non-native invasive species are in part successful because they produce harmful allelochemicals to which resident species are particularly susceptible because residents lack a shared evolutionary history with the invader. While allelopathic non-native invaders may reduce the growth and performance of neighbours through direct phytotoxicity, they may more often exert negative impacts through disruption of biotic interactions among resident species. Allelopathy by non-native plants may disrupt mutualisms between resident plants and microbes, plant-herbivore interactions or existing competitive and facilitative interactions among resident plants. For example, several non-native plants are known to disrupt the mutualism between resident plants and mycorrhizal fungi, reducing resident plant fitness to the benefit of the invader. Allelopathic non-natives may also disrupt interactions among resident plants and their herbivores when allelochemicals also influence herbivore behaviour or fitness. Alternatively, biotic interactions can also be protective for resident species, which may be less susceptible to the impacts of non-native species when their mutualisms are intact. As we advance our understanding of allelopathy and its role in mediating the impacts of invasive plant species, we may gain new insights by viewing invasions within a network context rather than focusing on pairwise interactions.

Assessment of the impact of plant species composition and drought stress on survival of strongylid third-stage larvae in a greenhouse experiment

2014 ◽  
Vol 113 (11) ◽  
pp. 4123-4131 ◽  
Author(s):  
Friederike Knapp-Lawitzke ◽  
Frank Küchenmeister ◽  
Kai Küchenmeister ◽  
Georg von Samson-Himmelstjerna ◽  
Janina Demeler
Keyword(s):  
Drought Stress ◽  
Species Composition ◽  
Plant Species ◽  
Greenhouse Experiment ◽  
Plant Species Composition ◽  
Third Stage ◽  
The Impact

The effect of invasive Lythrum salicaria pollen deposition on seed set in the native species Decodon verticillatus

Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Elizabeth M. Da Silva ◽  
Risa D. Sargent
Keyword(s):  
Native Species ◽  
Invasive Plant ◽  
Seed Set ◽  
Lythrum Salicaria ◽  
Pollen Deposition ◽  
Native Plant ◽  
Plant Populations ◽  
Hand Pollination ◽  
Whole Plants ◽  
The Impact

Relatively little attention has been paid to pollinator-mediated interactions among invasive and native plants in spite of the fact that pollen transfer between species in invaded communities has been shown to occur. In this study, we investigated the impact of pollen deposition from the invasive plant species Lythrum salicaria on seed set in a native species that is a member of the same family, Decodon verticillatus. Whole plants were subjected to hand pollination by conspecific (D. verticillatus only) or mixed (a 1:1 mixture of D. verticillatus and L. salicaria) pollen to determine if the addition of a mixed pollen load interferes with the ability of D. verticillatus pollen to set seed. We found the mixed pollen treatment reduced D. verticillatus seed set by 33.3% relative to the conspecific pollen treatment. Our study demonstrates that invasive plants have the potential to negatively impact the reproductive success of a native species through pollinator-mediated interactions. We discuss the potential implications of our findings to the evolution and persistence of native plant populations in invaded communities.

scholarly journals Micro-habitat and season dependent impact of the invasive Impatiens glandulifera on native vegetation

NeoBiota ◽  
2020 ◽  
Vol 57 ◽  
pp. 109-131
Author(s):  
Judith Bieberich ◽  
Heike Feldhaar ◽  
Marianne Lauerer
Keyword(s):  
Environmental Conditions ◽  
Native Species ◽  
Invasive Plant ◽  
Habitat Type ◽  
Context Dependency ◽  
Native Vegetation ◽  
Native Plant ◽  
Habitat Types ◽  
Impatiens Glandulifera ◽  
The Impact

The impact of invasive species is often difficult to assess due to species × ecosystem interactions. Impatiens glandulifera heavily invaded several habitat types in Central Europe but its impact on native plant communities is rated ambiguously. One reason could be that the impact differs between habitat types or even between environmentally heterogeneous patches (micro-habitats) within one habitat type. In the present study a vegetation survey was performed within heterogeneous riverside habitats in Germany investigating the impact of I. glandulifera on native vegetation in dependence of environmental conditions. The vegetation was recorded in summer and spring because of seasonal species turnover and thus potentially different impact of the invasive plant. We found that the cover of I. glandulifera depended on environmental conditions resulting in a patchy occurrence. I. glandulifera did not have any impact on plant alpha-diversity but reduced the cover of the native vegetation, especially of the dominant species. This effect depended on micro-habitat and season. The native vegetation was most affected in bright micro-habitats, especially those with a high soil moisture. Not distinguishing between micro-habitats, plant species composition was not affected in summer but in spring. However, environmental conditions had a higher impact on the native vegetation than I. glandulifera. We conclude that within riparian habitats the threat of I. glandulifera to the native vegetation can be rated low since native species were reduced in cover but not excluded from the communities. This might be due to patchy occurrence and year-to-year changes in cover of I. glandulifera. The context-dependency in terms of micro-habitat and season requires specific risk assessments which is also an opportunity for nature conservation to develop management plans specific to the different habitats. Particular attention should be given to habitats that are bright and very wet since the effect of I. glandulifera was strongest in these habitats.

scholarly journals Synthesis and Biological Activity of Brassinosteroid Analogues with a Nitrogen-Containing Side Chain

2020 ◽  
Vol 22 (1) ◽  
pp. 155
Author(s):  
Mikhail V. Diachkov ◽  
Karoll Ferrer ◽  
Jana Oklestkova ◽  
Lucie Rarova ◽  
Vaclav Bazgier ◽  
...  
Keyword(s):  
Biological Activity ◽  
Functional Groups ◽  
Side Chain ◽  
Biotic And Abiotic Stresses ◽  
Short Side ◽  
Arabidopsis Root ◽  
Physiological Processes ◽  
Growth Promoting ◽  
The Impact ◽  
Brassinosteroid Analogues

Brassinosteroids are a class of plant hormones that regulate a broad range of physiological processes such as plant growth, development and immunity, including the suppression of biotic and abiotic stresses. In this paper, we report the synthesis of new brassinosteroid analogues with a nitrogen-containing side chain and their biological activity on Arabidopis thaliana. Based on molecular docking experiments, two groups of brassinosteroid analogues were prepared with short and long side chains in order to study the impact of side chain length on plants. The derivatives with a short side chain were prepared with amide, amine and ammonium functional groups. The derivatives with a long side chain were synthesized using amide and ammonium functional groups. A total of 25 new brassinosteroid analogues were prepared. All 25 compounds were tested in an Arabidopsis root sensitivity bioassay and cytotoxicity screening. The synthesized substances showed no significant inhibitory activity compared to natural 24-epibrassinolide. In contrast, in low concentration, several compounds (8a, 8b, 8e, 16e, 22a and 22e) showed interesting growth-promoting activity. The cytotoxicity assay showed no toxicity of the prepared compounds on cancer and normal cell lines.

The Biology of Invasive Alien Plants in Canada. 4. Heracleum mantegazzianum Sommier & Levier

2006 ◽  
Vol 86 (2) ◽  
pp. 569-589 ◽  
Author(s):  
Nicholas A. Page ◽  
Ronald E. Wall ◽  
Stephen J. Darbyshire ◽  
Gerald A. Mulligan
Keyword(s):  
British Columbia ◽  
Urban Areas ◽  
Native Species ◽  
Invasive Plant ◽  
Leaf Shape ◽  
Herbarium Specimens ◽  
Natural Ecosystems ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
Heracleum Mantegazzianum

Heracleum mantegazzianum (giant hogweed) is an invasive alien plant of management concern in southern Canada where it has escaped from horticulture and established and spread in natural, ruderal, and agricultural ecosystems. It poses a threat to natural ecosystems and human health, and is also a weed in agricultural and urban areas. It is a member of the Carrot family (Apiaceae) and is closely related to the native species Heracleum maximum Bartram (cow-parsnip). It is a monocarpic perennial, which generally flowers in its 3rd or 4th year. Large size, leaf shape, dark reddish pigments in patches on stems and petioles, and fruit characteristics readily distinguish H. mantegazzianum from other plants in Canada. It is increasingly common in riparian areas, floodplains, and forest edges in or near urban areas in southwestern British Columbia and southern Ontario. Based on herbarium specimens, H. mantegazzianum was first recorded in Ontario in 1949, British Columbia in 1964, Nova Scotia in 1980, Quebec in 1990, and New Brunswick in 2000. The development of dense stands of H. mantegazzianum can also reduce the richness of native plants. Contact with H. mantegazzianum can cause phytophotodermatitis, a serious skin inflammation caused by UV photo-activation of furanocoumarins present in the sap. Control methods include herbicide application, mechanical cutting, and animal grazing, but strategies to address seed dispersal and re-establishment from dormant seed must also be adopted. Widespread establishment in southern Canada suggests that eradication is unlikely. However, range expansion and rapid population growth can be prevented through strategic management including public education. Key words: Giant hogweed, Heracleum mantegazzianum, Apiaceae, HERMZ, invasive plant, weed biology, furanocoumarins

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