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

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.

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

Botany ◽

10.1139/b11-001 ◽

2011 ◽

Vol 89 (2) ◽

pp. 141-146 ◽

Cited By ~ 11

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.

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Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA

International Journal of Wildland Fire ◽

10.1071/wf08194 ◽

2010 ◽

Vol 19 (4) ◽

pp. 490 ◽

Cited By ~ 7

Author(s):

Erich K. Dodson ◽

David W. Peterson ◽

Richy J. Harrod

Keyword(s):

Species Richness ◽

Plant Species ◽

Native Species ◽

Plant Cover ◽

Plant Species Richness ◽

Tree Regeneration ◽

Vegetation Recovery ◽

Native Vegetation ◽

Individual Plant ◽

Native Plant

Slope stabilisation treatments like mulching and seeding are used to increase soil cover and reduce runoff and erosion following severe wildfires, but may also retard native vegetation recovery. We evaluated the effects of seeding and fertilisation on the cover and richness of native and exotic plants and on individual plant species following the 2004 Pot Peak wildfire in Washington State, USA. We applied four seeding and three fertilisation treatments to experimental plots at eight burned sites in spring 2005 and surveyed vegetation during the first two growing seasons after fire. Seeding significantly reduced native non-seeded species richness and cover by the second year. Fertilisation increased native plant cover in both years, but did not affect plant species richness. Seeding and fertilisation significantly increased exotic cover, especially when applied in combination. However, exotic cover and richness were low and treatment effects were greatest in the first year. Seeding suppressed several native plant species, especially disturbance-adapted forbs. Fertilisation, in contrast, favoured several native understorey plant species but reduced tree regeneration. Seeding, even with native species, appears to interfere with the natural recovery of native vegetation whereas fertilisation increases total plant cover, primarily by facilitating native vegetation recovery.

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Slash Pile Burn Scar Restoration: Tradeoffs between Abundance of Non-Native and Native Species

Forests ◽

10.3390/f11080813 ◽

2020 ◽

Vol 11 (8) ◽

pp. 813

Author(s):

Ian Sexton ◽

Philip Turk ◽

Lindsay Ringer ◽

Cynthia S. Brown

Keyword(s):

Plant Species ◽

Native Species ◽

Invasive Plant ◽

Chemical Properties ◽

Rocky Mountain ◽

Native Plant ◽

Burn Scar ◽

Native Plant Species ◽

Burned Areas ◽

Soil Scarification

The accumulation of live and dead trees and other vegetation in forests across the western United States is producing larger and more severe wildfires. To decrease wildfire severity and increase forest resilience, foresters regularly remove excess fuel by burning woody material in piles. This common practice could also cause persistent ecosystem changes such as the alteration of soil physical and chemical properties due to extreme soil heating, which can favor invasion by non-native plant species. The abundance and species richness of native plant communities may also remain depressed for many years after burning has removed vegetation and diminished propagules in the soil. This adds to the vulnerability of burned areas to the colonization and dominance by invasive species. Research into the use of revegetation techniques following pile burning to suppress invasion is limited. Studies conducted in various woodland types that investigated revegetation of pile burn scars have met with varying success. To assess the effectiveness of restoring pile burn scars in Rocky Mountain National Park, Colorado, we monitored vegetation in 26 scars, each about 5 m in diameter, the growing season after burning. Later that summer, we selected 14 scars for restoration that included soil scarification, seed addition, and pine duff mulch cover. We monitored the scars for four years, pre-restoration, and three years post-restoration and found that the cover of seeded species exceeded the surrounding unburned areas and unseeded controls. The restoration seeding suppressed cover of non-native species as well as native species that were not seeded during restoration. Our results suggest that restoration of pile burn scars could be a useful tool to retard the establishment of invasive plant species when there are pre-existing infestations near scars. However, this must be weighed against the simultaneous suppression of native species recruitment. Monitoring for periods more than three years will help us understand how long the suppression of native and non-native species by restoration species may persist.

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The influence of warming and biotic interactions on the potential for range expansion of native and nonnative species

AoB Plants ◽

10.1093/aobpla/plaa040 ◽

2020 ◽

Vol 12 (5) ◽

Author(s):

Betsy von Holle ◽

Sören E Weber ◽

David M Nickerson

Keyword(s):

Plant Species ◽

Range Expansion ◽

Species Interactions ◽

Native Species ◽

Invasive Plant ◽

Soil Microbes ◽

Enemy Release ◽

Native Plant ◽

Soil Pathogens ◽

Microbe Interactions

Abstract Plant species ranges are expected to shift in response to climate change, however, it is unclear how species interactions will affect range shifts. Because of the potential for enemy release of invasive nonnative plant species from species-specific soil pathogens, invasive plants may be able to shift ranges more readily than native plant species. Additionally, changing climatic conditions may alter soil microbial functioning, affecting plant–microbe interactions. We evaluated the effects of site, plant–soil microbe interactions, altered climate, and their interactions on the growth and germination of three congeneric shrub species, two native to southern and central Florida (Eugenia foetida and E. axillaris), and one nonnative invasive from south America (E. uniflora). We measured germination and biomass for these plant species in growth chambers grown under live and sterile soils from two sites within their current range, and one site in their expected range, simulating current (2010) and predicted future (2050) spring growing season temperatures in the new range. Soil microbes (microscopic bacteria, fungi, viruses and other organisms) had a net negative effect on the invasive plant, E. uniflora, across all sites and temperature treatments. This negative response to soil microbes suggests that E. uniflora’s invasive success and potential for range expansion are due to other contributing factors, e.g. higher germination and growth relative to native Eugenia. The effect of soil microbes on the native species depended on the geographic provenance of the microbes, and this may influence range expansion of these native species.

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

Botany ◽

10.1139/cjb-2015-0237 ◽

2016 ◽

Vol 94 (6) ◽

pp. 481-491 ◽

Cited By ~ 5

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.

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The impacts of invasive plant species on the biodiversity of Australian rangelands

The Rangeland Journal ◽

10.1071/rj06014 ◽

2006 ◽

Vol 28 (1) ◽

pp. 27 ◽

Cited By ~ 58

Author(s):

A. C. Grice

Keyword(s):

Invasive Species ◽

Species Richness ◽

Plant Species ◽

Native Species ◽

Invasive Plant ◽

Plant Species Richness ◽

Native Plant ◽

Weed Species ◽

Ecological Processes ◽

Native Plant Species

Most parts of the Australian rangelands are at risk of invasion by one or more species of non-native plants. The severity of current problems varies greatly across the rangelands with more non-native plant species in more intensively settled regions, in climatic zones that have higher and more reliable rainfall, and in wetter and more fertile parts of rangeland landscapes. Although there is quantitative evidence of impacts on either particular taxonomic groups or specific ecological processes in Australian rangelands, a comprehensive picture of responses of rangeland ecosystems to plant invasions is not available. Research has been focused on invasive species that are perceived to have important effects. This is likely to down play the significance of species that have visually less dramatic influences and ignore the possibility that some species could invade and yet have negligible consequences. It is conceivable that most of the overall impact will come from a relatively small proportion of invasive species. Impacts have most commonly been assessed in terms of plant species richness or the abundance of certain groups of vertebrates to the almost complete exclusion of other faunal groups. All scientific studies of the impacts of invasive species in Australian rangelands have focused on the effects of individual invasive species although in many situations native communities are under threat from a complex of interacting weed species. Invasion by non-native species is generally associated with declines in native plant species richness, but faunal responses are more complex and individual invasions may be associated with increase, decrease and no-change scenarios for different faunal groups. Some invasive species may remain minor components of the vegetation that they invade while others completely dominate one stratum or the vegetation overall.

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Response of endemic and exotic earthworm communities to ecological restoration

10.7287/peerj.preprints.2017v1 ◽

2016 ◽

Author(s):

Stéphane Boyer ◽

Young-Nam Kim ◽

Mike H Bowie ◽

Marie-Caroline Lefort ◽

Nicholas M Dickinson

Keyword(s):

New Zealand ◽

Exotic Species ◽

Environmental Changes ◽

Farming Systems ◽

Native Vegetation ◽

Native Plant ◽

Plant Restoration ◽

Exotic Earthworms ◽

Study Sites ◽

The Impact

New Zealand has 23 exotic and more than 200 endemic earthworm species. Endemic earthworms disappeared quickly after vegetation clearance and land conversion to agriculture from the early C19th. Environmental changes associated with agronomic practices are believed to have been the main drivers for their disappearance. Exotic earthworms introduced from Europe have since largely replaced endemic earthworms into farming systems and have been intentionally propagated to increase production. Little is known about potential competition between endemic and exotic earthworms in New Zealand, and the capacity of exotic earthworms to extend their range into native habitats. Using two sites in the South Island of New Zealand, we investigated the impact of restoring native vegetation on earthworm communities. The study sites were Quail Island (Banks Peninsula), which has been undergoing native plant restoration for more than 30 years, and the Punakaiki Coastal Restoration Project (West Coast) where 130,000 native trees have been planted in retired pasture in the last seven years. At each site, soil samples (20 x 20 x 20 cm) were collected and hand sorted for earthworms. Sequential restoration plantings revealed that recolonisation by endemic earthworms increases with time after restoration at the two sample sites. With increasing age of the restoration, the biomass of endemic earthworm significantly increased, as did abundance at Punakaiki. However, exotic species did not disappear after restoration of native vegetation, even after 30 years in Quail Island. The persistence of exotic species leads to the cohabitation of the two communities and potential for interspecific competition.

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Neomarica caerulea (walking iris).

10.1079/isc.119832.20203482755 ◽

2020 ◽

Author(s):

Julissa Rojas-Sandoval

Keyword(s):

South Africa ◽

Central America ◽

Native Species ◽

Plant Species Richness ◽

Perennial Herb ◽

Native Vegetation ◽

Native Plant ◽

Native Plant Species ◽

The Caribbean ◽

Light Green

Abstract Neomarica caerulea is a clumping perennial herb often cultivated as an ornamental for its attractive, light green leaves and colourful flowers. It is native to Brazil and also widely cultivated. It has escaped from cultivation and can be found naturalized along roadsides, in abandoned farms and pastures and in disturbed sites in Central America, the Caribbean and South Africa. This species propagates by seed, but also by rhizomes and plantlets. Once established it can form dense colonies that prevent the regeneration of native vegetation and displace native species reducing native plant species richness. Currently it is listed as invasive in Cuba, though its impact is unknown.

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Non-Native Herbivores Promote Plant Invasions Away From Mountain Roads in the Andes

10.21203/rs.3.rs-979953/v1 ◽

2021 ◽

Author(s):

Valeria Aschero ◽

Agustina Barros ◽

Lorena Bonjour ◽

Ana Mazzolari ◽

Martín Pérez Sosa ◽

...

Keyword(s):

Protected Areas ◽

Native Species ◽

Plant Invasions ◽

Natural Vegetation ◽

Livestock Grazing ◽

Native Plant ◽

The Road ◽

The Andes ◽

The Impact

Abstract While the role of environmental filters, usually described by elevation as proxy, and anthropogenic disturbance as drivers of non-native plant diversity and abundance in mountains have been extensively studied, the impact of herbivores are less explored. Livestock grazing can facilitate the introduction of non-native species by seed dispersal and reduce biotic resistance due to consumption and trampling of native plants, even in the highest protected areas in the Andes. We here explored the effects of elevation, livestock and distance to the road on non-native and native plant distributions. Our results confirm the largely negative relationship of non-native plant richness and cover with elevation, with a peak in richness and cover at low to intermediate elevations. Similarly, we show a strong decline in non-native richness with increasing distance to the road, especially at low elevations, accompanied by a strong negative effect of roads on native species richness. Most importantly, however, we show that the presence of non-native herbivores greatly increases the cover of non-native species away from the roadside, identifying herbivore disturbance as a potential catalyst of non-native plant invasion into natural vegetation of high-Andean protected areas. Our results confirm the often-shown role of disturbance as driver of plant invasions in mountains, yet highlight the interactive effects of disturbance by roads and herbivory: roads funnel non-native species towards higher elevations, while non-native herbivores can promote non-native plant success away from the roadside and into the natural vegetation. Hence, regulating soil and non-native herbivory disturbance is important for minimizing plant invasions at high elevation in the Arid Andes.

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

Sustainability ◽

10.3390/su12155951 ◽

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.

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