Managing Spotted Knapweed (Centaurea stoebe)–Infested Rangeland after Wildfire

2010 ◽  
Vol 3 (2) ◽  
pp. 182-189
Author(s):  
Monica L. Pokorny ◽  
Jane M. Mangold ◽  
James Hafer ◽  
M. Kirk Denny
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Invasive Plants ◽  
Invasive Plant ◽  
Spotted Knapweed ◽  
Herbicide Application ◽  
Broadcast Application ◽  
Seed Mixture ◽  
Application Methods ◽  
And Performance

AbstractInvasive plants need to be managed after wildfire to suppress the invasive plant and to maintain or restore a desired plant community. Our study tested treatments that influence species availability and performance following a disturbance (wildfire). The overall objective was to determine the ability of herbicide and revegetation treatments to restore spotted knapweed–infested areas to desired plant communities after wildfire. The study consisted of a factorial combination of three herbicide application treatments (broadcast application, spot application, and no herbicide) and three seed mixture treatments (grass-only seed mix, a grass and forb seed mix, no seeding). Picloram was used for the herbicide. Both the broadcast and spot picloram application methods decreased spotted knapweed cover and density up to 80% while increasing desired grass cover and density up to 20% compared with the control. However, broadcast spraying picloram decreased species richness from 5.7 to 3.6 species 0.1 m−2 and decreased desired forb density and cover compared with spot-applied picloram treatment. Spot spraying resulted in an increase in other undesired forbs compared with broadcast spraying. Seeding with desired species had no effect on spotted knapweed cover or density. Spot spraying may help maintain desired species richness while managing spotted knapweed.

Negative per capita effects of two invasive plants, Lythrum salicaria and Phalaris arundinacea, on the moth diversity of wetland communities

2008 ◽  
Vol 99 (3) ◽  
pp. 229-243 ◽  
Author(s):  
S.S. Schooler ◽  
P.B. McEvoy ◽  
P. Hammond ◽  
E.M. Coombs
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Communities ◽  
Invasive Plants ◽  
Invasive Plant ◽  
Phalaris Arundinacea ◽  
Lythrum Salicaria ◽  
Trophic Levels ◽  
Plant Abundance ◽  
Per Capita

AbstractInvasive plants have been shown to negatively affect the diversity of plant communities. However, little is known about the effect of invasive plants on the diversity at other trophic levels. In this study, we examine the per capita effects of two invasive plants, purple loosestrife (Lythrum salicaria) and reed canary grass (Phalaris arundinacea), on moth diversity in wetland communities at 20 sites in the Pacific Northwest, USA. Prior studies document that increasing abundance of these two plant species decreases the diversity of plant communities. We predicted that this reduction in plant diversity would result in reduced herbivore diversity. Four measurements were used to quantify diversity: species richness (S), community evenness (J), Brillouin's index (H) and Simpson's index (D). We identified 162 plant species and 156 moth species across the 20 wetland sites. The number of moth species was positively correlated with the number of plant species. In addition, invasive plant abundance was negatively correlated with species richness of the moth community (linear relationship), and the effect was similar for both invasive plant species. However, no relationship was found between invasive plant abundance and the three other measures of moth diversity (J, H, D) which included moth abundance in their calculation. We conclude that species richness within, and among, trophic levels is adversely affected by these two invasive wetland plant species.

scholarly journals Competitive Interactions of Flowering Rush (Butomus umbellatus L.) Cytotypes in Submersed and Emergent Experimental Aquatic Plant Communities

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 40 ◽  
Author(s):  
Nathan E. Harms
Keyword(s):  
Plant Communities ◽  
Invasive Plants ◽  
Aquatic Plant ◽  
Invasive Plant ◽  
Common Garden ◽  
Competitive Interactions ◽  
Depth Gradient ◽  
Common Garden Experiments

The ability to invade communities in a variety of habitats (e.g., along a depth gradient) may facilitate establishment and spread of invasive plants, but how multiple lineages of a species perform under varying conditions is understudied. A series of greenhouse common garden experiments were conducted in which six diploid and four triploid populations of the aquatic invasive plant Butomus umbellatus L. (Butomaceae) were grown in submersed or emergent conditions, in monoculture or in a multispecies community, to compare establishment and productivity of cytotypes under competition. Diploid biomass overall was 12 times higher than triploids in the submersed experiment and three times higher in the emergent experiment. Diploid shoot:root ratio was double that of triploid plants in submersed conditions overall, and double in emergent conditions in monoculture. Relative interaction intensities (RII) indicated that triploid plants were sixteen times more negatively impacted by competition under submersed conditions but diploid plants were twice as impacted under emergent conditions. Recipient communities were similarly negatively impacted by B. umbellatus cytotypes. This study supports the idea that diploid and triploid B. umbellatus plants are equally capable of invading emergent communities, but that diploid plants may be better adapted for invading in submersed habitats. However, consistently lower shoot:root ratios in both monoculture and in communities suggests that triploid plants may be better-adapted competitors in the long term due to increased resource allocation to roots. This represents the first examination into the role of cytotype and habitat on competitive interactions of B. umbellatus.

scholarly journals Evaluating Restoration Methods across a Range of Plant Communities Dominated by Invasive Annual Grasses to Native Perennial Grasses

2011 ◽  
Vol 4 (3) ◽  
pp. 306-316 ◽  
Author(s):  
Priscilla A. Nyamai ◽  
Timothy S. Prather ◽  
John M. Wallace
Keyword(s):  
Soil Moisture ◽  
Plant Community ◽  
Plant Communities ◽  
Invasive Plants ◽  
Seed Predation ◽  
Native Species ◽  
Herbicide Application ◽  
Factors Affecting ◽  
Annual Grasses ◽  
Specific Factors

AbstractPrairies are imperiled habitats, with remnants being generally small and often existing in isolation. Invasive plants have the potential to invade not just the edge of small remnants but also the interior because smaller remnants experience greater edge effects than do large, contiguous prairies. Additionally, invasive plants limit recruitment of native plants, which can arrest secondary succession. We proposed to assess techniques for restoration that included removing annual grasses and supplementing native species recruitment with seeding of native grass and forb species. We also assessed the effect of specific factors affecting recruitment: soil moisture and seed predation. Treatments included broadcast, spot, or no application of the herbicides imazapic and glyphosate and with or without seeding plus mulch. With treatments nested within each of three plant communities, ranging from annual- to perennial-dominated communities, in four blocks per community, plant characteristics (percentage of cover and plant density), soil moisture availability, and seed-predation losses were measured along a plant community gradient within one season at two locations. A combination of broadcast herbicide application and seeding with mulching was found to be more effective in reducing annual grasses and enhancing the establishment of native grass species in predominately annual and mixed communities (annuals and perennials). Spot herbicide application was effective in predominately perennial communities, whereas only seeding native species did not improve recruitment. Although seed predation reduced seedling recruitment, mulch provided seed protection and enhanced soil moisture retention. Plant community response to imposed treatments differed among communities, suggesting that a decision support tool would facilitate management decisions tailored for each plant community. The decision tool would be useful to ensure that appropriate treatments are applied and that specific factors affecting recruitment, such as seed predation and soil moisture, are addressed.

Trained Dogs Outperform Human Surveyors in the Detection of Rare Spotted Knapweed (Centaurea stoebe)

2010 ◽  
Vol 3 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Kim M. Goodwin ◽  
Rick E. Engel ◽  
David K. Weaver
Keyword(s):  
Invasive Plants ◽  
Invasive Plant ◽  
Medium Size ◽  
Line Transect ◽  
Spotted Knapweed ◽  
Centaurea Stoebe ◽  
Large Size ◽  
Plant Monitoring ◽  
Small Targets ◽  
Better Than

AbstractInvasive plants have devastating effects on ecosystems and biodiversity that early intervention can prevent. Eradication or containment of new invasions is difficult to achieve because of constraints posed by the low density and detectability of individuals. Domestic dogs trained to cue on distinctive scents might provide an effective method to detect spotted knapweed. The objective of this study was to compare the accuracy and detection distances of dogs to humans in locating new spotted knapweed (Centaurea stoebe) invasions. Three dogs, trained to detect knapweed using scent discrimination and tracking techniques, were compared with human surveyors. Seven sampling units (0.5 ha [1.2 ac]) were delineated in a grazed dryland pasture. Dogs, with their handlers, and human surveyors performed line-transect surveys in fall 2005 and spring, summer, and fall 2006. Dog accuracy for large-size knapweed targets (infestations 0.52 m3 [18.4 ft3]) was similar to human accuracy and better than humans (94 vs. 78%) for medium-size targets (infestations 0.13m3). Dog accuracy (67%) was greater (> 81% probability) than humans (34%) for small targets (plants; 0.02 m3). Overall dog accuracy (81%) and F-measure scores (86%) were better than human scores, 59% and 74%, respectively. Human precision was greater (100%) than dogs at 94%. Dogs detected a larger percentage of small targets (80%) at distances greater than 7.9 m (26 ft) compared with humans at only 20%. Our results indicate dogs are more accurate than humans are, especially at critical detection of small spotted knapweed plants, and from greater distances. Invasive plant monitoring using detection dogs can provide greater overall accuracy of plant detection.

scholarly journals Effects of the invasive plant Xanthium strumarium on diversity of native plant species: A competitive analysis approach in North and Northeast China

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0228476
Author(s):  
Mazher Farid Iqbal ◽  
Ming-Chao Liu ◽  
Aafia Iram ◽  
Yu-Long Feng
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Communities ◽  
Northeast China ◽  
Invasive Plant ◽  
Diversity Index ◽  
Diversity Indices ◽  
Xanthium Strumarium ◽  
Native Plant ◽  
Native Plant Species

Xanthium strumarium is native to North America and now has become one of the invasive alien species (IAS) in China. In order to detect the effects of the invader on biodiversity and evaluate its suitable habitats and ecological distribution, we investigated the abundance, relative abundance, diversity indices, and the number of the invasive and native plants in paired invaded and non-invaded quadrats in four locations in North and Northeast China. We also analyzed the effects of monthly mean maximum and minimum temperatures, relative humidity (%), and precipitations (mm). Strong positive significant (P < 0.01) correlation and maximum interspecific competition (41%) were found in Huailai between invaded and non-invaded quadrats. Shannon’s Diversity Index showed that non-invaded plots had significantly (P < 0.05) more diversified species than invaded ones. The significant (P < 0.05) Margalef’s Richness Index was found in Huailai and Zhangjiakou in non-invaded recorded heterogeneous nature of plant communities. Similarly, significant (P < 0.05) species richness found in Huailai and Zhangjiakou in non-invaded quadrats compared to invaded ones. Maximum evenness of Setaria feberi (0.47, 0.37), Seteria viridis (0.43) found in Fushun and Zhangjiakou recorded more stable in a community compared to other localities. Evenness showed positive relationship of Shannon Entropy within different plant species. The higher dissimilarity in plant communities found in Huailai (87.06%) followed by Yangyuan (44.43%), Zhangjiakou (40.13%) and Fushun (29.02%). The significant (P < 0.01) value of global statistics R (0.943/94.3%) showed high species diversity recorded in Huailai followed by Zhangjiakou recorded by non-metric multidimensional scaling and analysis of similarity between invaded and non-invaded plots. At the end it was concluded that the diversity indices reduced significantly (P < 0.05) in invaded quadrats indicated that native plant species become less diverse due to X. strumarium invasion. The degrees of X. strumarium invasion affected on species richness resulted to reduce diversity indices significantly in invaded quadrats.

scholarly journals Herbicides to Kill Invasive Trees in Home Landscapes and Surrounding Natural Areas

EDIS ◽  
2016 ◽  
Vol 2016 (6) ◽  
pp. 5
Author(s):  
Stephen F. Enloe ◽  
Kenneth Langeland
Keyword(s):  
Plant Species ◽  
Invasive Plants ◽  
Invasive Plant ◽  
Private Property ◽  
Herbicide Application ◽  
Natural Areas ◽  
Property Owners ◽  
Cut Stump ◽  
And Control ◽  
And Training

Several plant species that are invasive in natural areas of public lands also occur on private property. Invasive plants on private property that thrive within both landscaped and surrounding natural areas can serve as a source of infestation to other natural areas. Therefore, property owners are encouraged to remove invasive plant species from both areas. This 5-page fact sheet is a major revision that discusses different herbicides, hand-pulling, stump grinding, foliar herbicide application, cut stump herbicide application, basal bark herbicide application, hack-and-squirt, frill, or girdle herbicide application, licenses and training, and control of specific invasive plants. Written by K. A. Langeland and S. F. Enloe, and published by the UF May 2016. http://edis.ifas.ufl.edu/ag259

Are We “Missing the Boat” on Preventing the Spread of Invasive Plants in Rangelands?

2011 ◽  
Vol 4 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Kirk W. Davies ◽  
Dustin D. Johnson
Keyword(s):  
Plant Communities ◽  
Invasive Plants ◽  
Invasive Plant ◽  
Biotic Resistance ◽  
Plant Management ◽  
Native Plant ◽  
Prevention Strategies ◽  
Negative Effects ◽  
Invasive Plant Management ◽  
Management Actions

AbstractInvasive plants are negatively affecting the ecological and economic production of rangelands by reducing resource productivity, decreasing biodiversity, displacing native vegetation, and altering ecosystem processes and functions. However, despite these well-known negative effects, once invasive plants are regionally established, limited effort is directed at preventing their continued spread across rangelands. Most efforts are directed at restoration at specific locations while additional rangelands are invaded. Restoring native plant communities invaded by exotic plants is frequently unsuccessful, especially in more arid environments, and is often too costly to apply at the scale required to make meaningful progress in reducing invasive plant populations relative to their expansion. Of the few prevention efforts being implemented, most are a second priority to control and restoration efforts. Integrating strategies to prevent new infestations and restrict the expansion of existing populations in invasive plant management programs is critical to limiting the negative effects of invasive plants in rangelands. However, we are “missing the boat” on this issue by not providing sufficiently developed and validated management actions. Limited information is available for developing management strategies to prevent the spread of invasive plants, although it has been suggested that land managers need to increase biotic resistance of desired plant communities, decrease invasive plant propagule pressure, and eradicate small incipient infestations to prevent the continued expansion of invasive plants. Thus, instead of scientifically validated methods developed to limit the spread of invasive plants, managers are often left with vague suggestions for preventing the continued spread of invasive plants. We suggest that if prevention is going to be successful, researchers are going to need to conduct more applied research to provide land managers with specific prevention strategies and quantify the benefits of various prevention strategies.

scholarly journals Disentangling the Ecological Determinants of Species and Functional Trait Diversity in Herb-Layer Plant Communities in European Temperate Forests

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 552
Author(s):  
Janez Kermavnar ◽  
Lado Kutnar ◽  
Aleksander Marinšek
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Communities ◽  
Functional Trait ◽  
Forest Stand ◽  
Relative Importance ◽  
Herb Layer ◽  
Bud Bank ◽  
Tree Species Composition ◽  
Stand Characteristics

Forest herb-layer vegetation responds sensitively to environmental conditions. This paper compares drivers of both taxonomic, i.e., species richness, cover and evenness, and functional herb-layer diversity, i.e., the diversity of clonal, bud bank and leaf-height-seed plant traits. We investigated the dependence of herb-layer diversity on ecological determinants related to soil properties, climatic parameters, forest stand characteristics, and topographic and abiotic and biotic factors associated with forest floor structure. The study was conducted in different forest types in Slovenia, using vegetation and environmental data from 50 monitoring plots (400 m2 each) belonging to the ICP Forests Level I and II network. The main objective was to first identify significant ecological predictors and then quantify their relative importance. Species richness was strongly determined by forest stand characteristics, such as richness of the shrub layer, tree layer shade-casting ability as a proxy for light availability and tree species composition. It showed a clear positive relation to soil pH. Variation in herb-layer cover was also best explained by forest stand characteristics and, to a lesser extent, by structural factors such as moss cover. Species evenness was associated with tree species composition, shrub layer cover and soil pH. Various ecological determinants were decisive for the diversity of below-ground traits, i.e., clonal and bud bank traits. For these two trait groups we observed a substantial climatic signal that was completely absent for taxonomy-based measures of diversity. In contrast, above-ground leaf-height-seed (LHS) traits were driven exclusively by soil reaction and nitrogen availability. In synthesis, local stand characteristics and soil properties acted as the main controlling factors for both species and trait diversity in herb-layer communities across Slovenia, confirming many previous studies. Our findings suggest that the taxonomic and functional facets of herb-layer vegetation are mainly influenced by a similar set of ecological determinants. However, their relative importance varies among individual taxonomy- and functional trait-based diversity measures. Integrating multi-faceted approaches can provide complementary information on patterns of herb-layer diversity in European forest plant communities.

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