Invasive plant species are locally adapted just as frequently and at least as strongly as native plant species

Since honeybees (Apis mellifera) were introduced to North America in the 1600’s, their influence has been profound and widespread. As pollinators, honeybees are extremely valuable economically and are vital to crop pollination. However, their presence has affected native ecosystems, including the plains ecosystem in Colorado. Using recruitment and other unique foraging characteristics, honeybees may be out-competing native pollinators for nectar and pollen resources. Our study was designed to determine if A. mellifera has a preference for exotic or native plants. We observed patches of exotic plants and patches of native plants and recorded the type of bee (exotic or native) that visited each flowering head. We also examined data from Kearns and Oliveras (unpublished), which illustrates that invasive plant species are also popular with native bees, and may draw vital pollinators away from native plants. Our results indicate that honeybees prefer to visit exotic invasive plant species to native plants. Consequently, honeybees may contribute to the spread of exotic plant species and the decline of native plant species, reducing biodiversity. Thus, native plants are doubly jeopardized. The invasion of exotic flora and fauna into native ecosystems on the plains of Colorado is part of a worldwide phenomenon of species invasion, and researchers must continue to investigate interspecies relationships to minimize the potential negative effects of invasive species.

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Are declines in insects and insectivorous birds related?

The Condor ◽

10.1093/ornithapp/duaa059 ◽

2021 ◽

Author(s):

Douglas W Tallamy ◽

W Gregory Shriver

Keyword(s):

Plant Species ◽

Invasive Plant ◽

Bird Species ◽

Insect Herbivores ◽

Native Plant ◽

Insectivorous Birds ◽

Population Declines ◽

Native Plant Species ◽

Host Plant Specialization ◽

Scale Population

Abstract A flurry of recently published studies indicates that both insects and birds have experienced wide-scale population declines in the last several decades. Curiously, whether insect and bird declines are causally linked has received little empirical attention. Here, we hypothesize that insect declines are an important factor contributing to the decline of insectivorous birds. We further suggest that insect populations essential to insectivorous birds decline whenever non-native lumber, ornamental, or invasive plant species replace native plant communities. We support our hypothesis by reviewing studies that show (1) due to host plant specialization, insect herbivores typically do poorly on non-native plants; (2) birds are often food limited; (3) populations of insectivorous bird species fluctuate with the supply of essential insect prey; (4) not all arthropod prey support bird reproduction equally well; and (5) terrestrial birds for which insects are an essential source of food have declined by 2.9 billion individuals over the last 50 years, while terrestrial birds that do not depend on insects during their life history have gained by 26.2 million individuals, a 111-fold difference. Understanding the consequences of insect declines, particularly as they affect charismatic animals like birds, may motivate land managers, homeowners, and restoration ecologists to take actions that reverse these declines by favoring the native plant species that support insect herbivores most productively.

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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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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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An Invasive Plant Species Decreases Native Plant Reproductive Success

Natural Areas Journal ◽

10.3375/043.034.0408 ◽

2014 ◽

Vol 34 (4) ◽

pp. 465-469 ◽

Cited By ~ 4

Author(s):

Brenda Molano-Flores

Keyword(s):

Reproductive Success ◽

Plant Species ◽

Invasive Plant ◽

Invasive Plant Species ◽

Native Plant ◽

Plant Reproductive Success

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Identifying the Spectral Signatures of Invasive and Native Plant Species in Two Protected Areas of Pakistan through Field Spectroscopy

Remote Sensing ◽

10.3390/rs13194009 ◽

2021 ◽

Vol 13 (19) ◽

pp. 4009

Author(s):

Iram M. Iqbal ◽

Heiko Balzter ◽

Firdaus-e-Barren ◽

Asad Shabbir

Keyword(s):

Protected Areas ◽

Plant Species ◽

Invasive Plant ◽

Invasive Plant Species ◽

Native Plant ◽

Spectral Signatures ◽

Red Edge ◽

Field Spectroscopy ◽

Reserve Forest ◽

Spectral Separability

Globally, biological invasions are considered as one of the major contributing factors for the loss of indigenous biological diversity. Hyperspectral remote sensing plays an important role in the detection and mapping of invasive plant species. The main objective of this study was to discriminate invasive plant species from adjacent native species using a ground-based hyperspectral sensor in two protected areas, Lehri Reserve Forest and Jindi Reserve Forest in Punjab, Pakistan. Field spectral measurements were collected using an ASD FieldSpec handheld2TM spectroradiometer (325–1075 nm) and the discrimination between native and invasive plant species was evaluated statistically using hyperspectral indices as well as leaf wavelength spectra. Finally, spectral separability was calculated using Jeffries Matusita distance index, based on selected wavebands. The results reveal that there were statistically significant differences (p < 0.05) between the different spectral indices of most of the plant species in the forests. However, the red-edge parameters showed the highest potential (p < 0.001) to discriminate different plant species. With leaf spectral signatures, the mean reflectance between all plant species was significantly different (p < 0.05) at 562 (75%) wavelength bands. Among pairwise comparisons, invasive Leucaena leucocephala showed the best discriminating ability, with Dodonaea viscosa having 505 significant wavebands showing variations between them. Jeffries Matusita distance analysis revealed that band combinations of the red-edge region (725, 726 nm) showed the best spectral separability (85%) for all species. Our findings suggest that it is possible to identify and discriminate invasive species through field spectroscopy for their future monitoring and management. However, the upscaling of hyperspectral measurements to airborne and satellite sensors can provide a reliable estimation of invasion through mapping inside the protected areas and can help to conserve biodiversity and environmental ecosystems in the future.

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Invasive Plants Differentially Impact Forest Invertebrates, Providing Taxon-Specific Benefits by Enhancing Structural Complexity

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.682140 ◽

2021 ◽

Vol 9 ◽

Author(s):

Andrew P. Landsman ◽

John Paul Schmit ◽

Elizabeth R. Matthews

Keyword(s):

Community Composition ◽

Plant Species ◽

Invasive Plants ◽

Invasive Plant ◽

Structural Complexity ◽

Plant Management ◽

Grass Cover ◽

Invasive Plant Species ◽

Native Plant ◽

Japanese Stiltgrass

Exotic plant species often negatively affect native herbivores due to the lack of palatability of the invading plant. Although often unsuitable as food, certain invasive species may provide non-nutritional ecological benefits through increased habitat structural complexity. To understand the potential for common invasive forest plant species of the eastern United States to benefit invertebrate communities, we examined the functional and taxonomic community composition of forest insects and spiders in long-term monitoring plots that contained invasive plant species. The extent of invasive plant species ground cover significantly altered spider community composition as categorized by hunting guild. Areas with higher invasive herbaceous and grass cover contained a higher abundance of space web-weaving and hunting spiders, respectively. Spider species richness and total invertebrate abundance also increased with greater invasive grass cover. Still, these trends were driven by just two invasive plant species, garlic mustard and Japanese stiltgrass, both of which have previously been shown to provide structural benefits to native invertebrate taxa. While these two species may improve the structural component of understory forest habitat, many invertebrate groups were not significantly correlated with other prevalent invasive plants and one species, mock strawberry, negatively affected the abundance of certain insect taxa. Particularly in forests with reduced native plant structure, invasive plant management must be conducted with consideration for holistic habitat quality, including both plant palatability and structure.

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Increased precipitation magnifies the effects of N addition on performance of invasive plants in subtropical native communities

Journal of Plant Ecology ◽

10.1093/jpe/rtab103 ◽

2021 ◽

Author(s):

Xiang-Qin Li ◽

Sai-Chun Tang ◽

Yu-Mei Pan ◽

Chun-Qiang Wei ◽

Shi-Hong Lü

Keyword(s):

Invasive Species ◽

Plant Species ◽

Aboveground Biomass ◽

Invasive Plant ◽

Plant Invasions ◽

N Deposition ◽

N Addition ◽

Native Plant ◽

Native Plant Species ◽

Native Communities

Abstract Aims Nitrogen (N) deposition, precipitation and their interaction affect plant invasions in temperate ecosystems with limiting N and water resources, but whether and how they affect plant invasions in subtropical native communities with abundant N and precipitation remains unclear. Methods We constructed in situ artificial communities with 12 common native plant species in a subtropical system and introduced four common invasive plant species and their native counterparts to these communities. We compared plant growth and establishment of introduced invasive species and native counterparts in communities exposed to ambient (CK), N addition (N+), increased precipitation (P+) and N addition plus increased precipitation (P+N+). We also investigated the density and aboveground biomass of communities under such conditions. Important Findings P+ alone did not enhance the performance of invasive species or native counterparts. N+ enhanced only the aboveground biomass and relative density of invasive species. P+N+ enhanced the growth and establishment performance of both invasive species and native counterparts. Most growth and establishment parameters of invasive species were greater than those of native counterparts under N+, P+ and P+N+ conditions. The density and aboveground biomass of native communities established by invasive species were significantly lower than those of native communities established by native counterparts under P+N+ conditions. These results suggest that P+ may magnify the effects of N+ on performance of invasive species in subtropical native communities where N and water are often abundant, which may help to understand the effect of global change on plant invasion in subtropical ecosystems.

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