Assessing vulnerability and resistance to plant invasions A native community perspective

Abstract Risk assessments of biological invasions rarely account for native species performance and community features, but this assessment could provide additional insights for management aimed at decreasing vulnerability or increasing resistance of a plant community to invasions. To gather information on the drivers of native plant communities’ vulnerability and resistance to invasion, we conducted a literature search and meta-analysis. From the data collected we compared native and invasive plant performance between sites with high and low levels of invasion. We then investigated under which conditions native performance increased, decreased, or did not change with respect to invasive plants. We analyzed data from 214 publications summing to 506 observations. There were six main drivers of vulnerability to invasion: disturbance, decrease in resources, increase in resources, lack of biotic resistance, lack of natural enemies, and differences in propagule availability between native and invasive species. The two mechanisms of vulnerability to invasion associated with a strong decline in native plant performance were propagule availability and lack of biotic resistance. Native plants marginally benefited from enemy release and from decreases in resources, while invasive plants strongly benefited from both increased resources and lack of enemies. Fluctuation of resources, decreases and increases, were strongly associated with higher invasive performance while native plants varied in their response. These differences were particularly strong in instances of decreasing water or nutrients, and of increasing light and nutrients. We found overall neutral to positive responses of native plant communities to disturbance; but natives were outperformed by invasive species when disturbance was caused by human activities. We identified ecosystem features associated with both vulnerability and resistance to invasion, then used our results to inform management aimed at protecting the native community.

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Allelopathy is pervasive in invasive plants

Biological Invasions ◽

10.1007/s10530-020-02383-6 ◽

2020 ◽

Author(s):

Susan Kalisz ◽

Stephanie N. Kivlin ◽

Lalasia Bialic-Murphy

Keyword(s):

Invasive Species ◽

Invasive Plants ◽

Native Species ◽

Invasive Plant ◽

Native Plants ◽

Plant Performance ◽

Native Plant ◽

Plant Phylogeny ◽

Plant Families ◽

Allelopathic Compounds

Abstract Invasive species utilize a wide array of trait strategies to establish in novel ecosystems. Among these traits is the capacity to produce allelopathic compounds that can directly inhibit neighboring native plants or indirectly suppress native plants via disruption of beneficial belowground microbial mutualisms, or altered soil resources. Despite the well-known prevalence of allelopathy among plant taxa, the pervasiveness of allelopathy among invasive plants is unknown. Here we demonstrate that the majority of the 524 invasive plant species in our database produce allelochemicals with the potential to negatively affect native plant performance. Moreover, allelopathy is widespread across the plant phylogeny, suggesting that allelopathy could have a large impact on native species across the globe. Allelopathic impacts of invasive species are often thought to be present in only a few plant clades (e.g., Brassicaceae). Yet our analysis shows that allelopathy is present in 72% of the 113 plant families surveyed, suggesting that this ubiquitous mechanism of invasion deserves more attention as invasion rates increase across the globe.

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Interactions between invasive plants and heavy metal stresses: a review

Journal of Plant Ecology ◽

10.1093/jpe/rtab100 ◽

2021 ◽

Author(s):

Jian Li ◽

Zhanrui Leng ◽

Yueming Wu ◽

Yizhou Du ◽

Zhicong Dai ◽

...

Keyword(s):

Invasive Species ◽

Invasive Plants ◽

Native Plants ◽

Escape Behavior ◽

Negative Influence ◽

Plant Litter ◽

Global Changes ◽

Native Plant ◽

Anthropogenic Contamination ◽

The Impact

Abstract Global changes have altered the distribution pattern of the plant communities, including invasive species. Anthropogenic contamination may reduce native plant resistance to the invasive species. Thus, the focus of the current review is on the contaminant biogeochemical behavior among native plants, invasive species and the soil within the plant-soil ecosystem to improve our understanding of the interactions between invasive plants and environmental stressors. Our studies together with synthesis of the literature showed that a) the impacts of invasive species on environmental stress were heterogeneous, b) the size of the impact was variable, and c) the influence types were multidirectional even within the same impact type. However, invasive plants showed self-protective mechanisms when exposed to heavy metals (HMs) and provided either positive or negative influence on the bioavailability and toxicity of HMs. On the other hand, HMs may favor plant invasion due to the widespread higher tolerance of invasive plants to HMS together with the “escape behavior” of native plants when exposed to toxic HM pollution. However, there has been no consensus on whether elemental compositions of invasive plants are different from the natives in the polluted regions. A quantitative research comparing plant, litter and soil contaminant contents between native plants and the invaders in a global context is an indispensable research focus in the future.

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Increase in nutrient availability promotes success of invasive plants through increasing growth and decreasing anti-herbivory defenses

10.1101/2021.10.18.464765 ◽

2021 ◽

Author(s):

Liping Shan ◽

Ayub M.O. Oduor ◽

Wei Huang ◽

Yanjie Liu

Keyword(s):

Invasive Species ◽

Plant Species ◽

Invasive Plants ◽

Nutrient Availability ◽

Nutrient Enrichment ◽

Native Species ◽

Native Plants ◽

Native Plant ◽

Simulated Herbivory ◽

Native Plant Species

Invasive plant species often exhibit greater growth and lower anti-herbivory defense than native plant species. However, it remains unclear how nutrient enrichment of invaded habitats may interact with competition from resident native plants to affect growth and defense of invasive plants. In a greenhouse experiment, we grew five congeneric pairs of invasive and native plant species under two levels of nutrient availability (low vs. high) that were fully crossed with simulated herbivory (clipping vs. no-clipping) and competition (alone vs. competition). Invasive plants produced more gibberellic acid, and grew larger than native species. Nutrient enrichment caused a greater increase in total biomass of invasive plants than of native plants, especially in the absence of competition or without simulated herbivory treatment. Nutrient enrichment decreased leaf flavonoid contents of invasive plants under both simulated herbivory conditions, but increased flavonoid of native plants under simulated herbivory condition. Nutrient enrichment only decreased tannins production of invasive species under competition. For native species, it enhanced their tannins production under competition, but decreased the chemicals when growing alone. The results indicate that the higher biomass production and lower flavonoids production in response to nutrient addition may lead to competitive advantage of invasive species than native species.

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

Invasive Plant Science and Management ◽

10.1614/ipsm-d-10-00030.1 ◽

2011 ◽

Vol 4 (1) ◽

pp. 166-171 ◽

Cited By ~ 22

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.

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Tests of Hexazinone and Tebuthiuron for Control of Exotic Plants in Kauai, Hawaii

Forests ◽

10.3390/f10070576 ◽

2019 ◽

Vol 10 (7) ◽

pp. 576

Author(s):

Wang ◽

Awaya ◽

Zhu ◽

Motooka ◽

Nelson ◽

...

Keyword(s):

Invasive Plants ◽

Loblolly Pine ◽

Native Species ◽

Native Plants ◽

Early Period ◽

Metrosideros Polymorpha ◽

Native Plant ◽

Weed Species ◽

Invasive Weed ◽

Native Plant Species

Non-native plant species have become serious pests in Hawaii’s delicate island ecosystems. It is necessary to control invasive plants. The herbicides hexazinone and tebuthiuron were evaluated for defoliation efficacy to control several major invasive plants and for non-target effects on native plants at Site I in a rainforest at 1200 m elevation and Site II in a mesic area at 640 m elevation on the island of Kauai, Hawaii. The invasive weed species in the sites included daisy fleabane (Erigeron karvinskianus DC.), faya tree (Myrica faya Ait.), strawberry guava (Psidium cattleyanum Sabine), banana passion fruit (Passiflora mollissima Bailey), vaseygrass (Paspalum urvillei Steud.), and highbush blackberry (Rubus argutus Link. 1822). Native plants included ohia lehua (Metrosideros polymorpha Gaudich.), naupaka (Scaevola cerasifolia Labill.), pilo (Hedyotis mannii), hona (Urera glabra (Hook. & Arn.)), aalii (Dodonaea viscosa Jacq.), and amau (Sadleria sp.). The results showed that broadcast applications of hexazinone granules and tebuthiuron pellets were effective on some of those invasive species. Herbicidal tolerance varied among the native species. For example, D. viscosa showed high tolerance to hexazinone. S. cerasifolia was susceptible to hexazinone, but not to tebuthiuron. The inconsistent defoliation of Sadleria sp. occurred among different applications rates of the two herbicides. M. polymorpha, particularly when it was small, could tolerate hexazinone and tebuthiuron. U. glabra was severely injured by the two herbicides. H. mannii was moderately tolerant to hexazinone, but fairly sensitive to tebuthiuron. The invasive loblolly pine (Pinus taeda L.) was highly tolerant to hexazinone, but was very sensitive to tebuthiuron. M. faya was very sensitive to hexazinone, but very tolerant to tebuthiuron. P. cattleyanum was sensitive to both herbicides. Six and nine months after hexazinone and tebuthiuron treatment, respectively, native plants were transplanted into the Sites to observe injury from residual herbicides. Approximately less than 10% mortality was observed for the out-planted native species three months after planting (MAP), indicating that the native species showed less injury in the early period of transplant. The mortality of the three endangered species Kauai hau kuahiwi (Hibiscadelphis distans), Kauai delissea (Delissea rhytidosperma H.Mann) and kawawaenohu (Alsinidendron lynchnoides), however, increased as the MAP increased. Overall, broadcast treatments of hexazinone and tebuthiuron at rates higher than 1 kg active ingredient per hectare would be problematic. The dissipation half-life values of hexazinone and tebuthiuron in the 1-15 cm layer of soils at the two sites were approximately 7 days and greater than 180 days, respectively.

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Comparing Effectiveness and Impacts of Japanese Barberry (Berberis thunbergii) Control Treatments and Herbivory on Plant Communities

Invasive Plant Science and Management ◽

10.1614/ipsm-d-13-00004.1 ◽

2013 ◽

Vol 6 (4) ◽

pp. 459-469 ◽

Cited By ~ 12

Author(s):

Jeffrey S. Ward ◽

Scott C. Williams ◽

Thomas E. Worthley

Keyword(s):

Invasive Species ◽

Plant Communities ◽

Initial Treatment ◽

Prescribed Burning ◽

Labor Cost ◽

Native Plant ◽

Minimal Impact ◽

Japanese Barberry ◽

Treatment Type

AbstractTwo factors that can degrade native plant community composition and structure, and hinder restoration efforts, are invasive species and chronic overbrowsing by ungulates such as white-tailed deer. Beginning in 2007, the effectiveness, costs, and impacts of Japanese barberry control treatments and herbivory on nonnative and native plant communities was examined at eight study areas over 4 to 5 yr. Prescribed burning and mechanical mowing by wood shredder or brush saw were utilized as initial treatments to reduce the aboveground portion of established barberry and were equally effective. Without a follow-up treatment, barberry had recovered to 56 to 81% of pretreatment levels 50 to 62 mo after initial treatment. Follow-up treatments in mid-summer to kill new sprouts included directed heating and foliar herbicide applications. Relative to untreated controls, follow-up treatments lowered barberry cover 50 to 62 mo after initial treatment by at least 72%. Although all follow-up treatments were equally effective, the labor cost of directed heating was four times higher than for herbicide applications. Follow-up treatment type (directed heating vs. herbicide) had minimal impact on species other than barberry. White-tailed deer herbivory had a larger impact on other species than did barberry control treatments. Native grass and fern cover was higher outside of exclosures. Areas inside exclosures had higher cover of Oriental bittersweet and multiflora rose, but not Japanese barberry. Thus, recovery of native communities will require more than simply removing the dominant invasive species where deer densities are high. Excellent reduction of Japanese barberry cover can be achieved using either directed heating or herbicides as follow-up treatments in a two-step process, but other invasive plants may become a problem when barberry is removed if deer populations are low.

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Enemy release mitigates inbreeding depression in native and invasive Silene latifolia populations: experimental insight into the role of inbreeding × environment interactions in invasion success

10.1101/401430 ◽

2018 ◽

Cited By ~ 1

Author(s):

Karin Schrieber ◽

Sabrina Wolf ◽

Catherina Wypior ◽

Diana Höhlig ◽

Stephen R. Keller ◽

...

Keyword(s):

Genetic Differentiation ◽

Inbreeding Depression ◽

Invasive Plants ◽

Natural Enemies ◽

Invasion Success ◽

Interactive Effects ◽

Plant Performance ◽

Silene Latifolia ◽

Enemy Release ◽

Fruit Number

AbstractInbreeding and enemy infestation are common in plants and can synergistically reduce their performance. This inbreeding × environment (I×E) interaction may be of particular importance for the success of plant invasions if introduced populations experience a release from attack by natural enemies relative to their native conspecifics. Using native and invasive plant populations, we investigate whether inbreeding affects infestation damage, whether inbreeding depression in performance is mitigated by enemy release and whether genetic differentiation among native and invasive plants modifies these I×E interactions. We used the plant invader Silene latifolia and its natural enemies as a study system. We performed two generations of experimental out- and inbreeding within eight native (European) and eight invasive (North American) S. latifolia populations under controlled conditions using field-collected seeds. Subsequently, we exposed the offspring to an enemy exclusion and inclusion treatment in a common garden in the species’ native range to assess the interactive effects of population origin (range), breeding treatment and enemy treatment on infestation damage as well as plant performance. Inbreeding increased flower and leaf infestation damage in plants from both ranges, but had opposing effects on fruit damage in native versus invasive plants. Both inbreeding and enemy infestation had negative effects on plant performance, whereby inbreeding depression in fruit number was higher in enemy inclusions than exclusions in plants from both ranges. Moreover, the magnitude of inbreeding depression in fruit number was lower in invasive than native populations. Our results support that inbreeding increases enemy susceptibility of S. latifolia, which magnifies inbreeding depression in the presence of enemies. Enemy release in the invaded habitat may thus increase the persistence of inbred founder populations and thereby contribute to successful invasion. Moreover, our findings emphasize that genetic differentiation among native and invasive plants can shape the magnitude and even the direction of inbreeding effects.

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Hiking and Livestock Favor Non-Native Plants in The High Andes

10.21203/rs.3.rs-781693/v1 ◽

2021 ◽

Author(s):

María Alisa Alvarez ◽

Ana Agustina Barros ◽

Diego Pedro Vázquez ◽

Lorena de Jesús Bonjour ◽

Jonas Lembrechts ◽

...

Keyword(s):

Community Composition ◽

Native Plants ◽

Environmental Filtering ◽

Elevational Gradient ◽

Native Vegetation ◽

Native Plant ◽

Native Community ◽

Upper Limits ◽

Native Plant Community ◽

Facilitative Interactions

Abstract Hikers and livestock using mountain trails damage native vegetation and act as seed vectors, thus favouring the spread of non-native plants. We evaluated the effect of trails and livestock abundance on the success of non-native plants in the arid central Andes of Argentina. We surveyed six trails, covering elevations between 2400 m and 3570 m a.s.l. and recorded non-native and native vegetation using transects distributed along the elevational gradient and spanning distances up to 22 m from the trail. We assessed how non-native occurrence, richness and cover varied with distance from the trail, intensity of use by livestock, native plant community composition and elevation. We found that trails favoured non-native occurrence, but did not influence richness and cover, while livestock favoured non-native occurrence, richness and cover. Non-native richness and cover decreased with elevation and varied with native community composition. In addition, non-native richness was positively correlated with native shrub cover suggesting possible facilitative interactions. Our results show that despite strong environmental filtering that decreases non-native abundance with elevation, non-natives occur up to the upper limits of vegetation, and that trails and livestock favour their spread in the mountains.

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Meta-Analysis of Exotic Forages as Invasive Plants in Complex Multi-Functioning Landscapes

Invasive Plant Science and Management ◽

10.1614/ipsm-d-14-00076.1 ◽

2015 ◽

Vol 8 (3) ◽

pp. 292-306 ◽

Cited By ~ 12

Author(s):

John Derek Scasta ◽

David M. Engle ◽

Samuel D. Fuhlendorf ◽

Daren D. Redfearn ◽

Terrance G. Bidwell

Keyword(s):

Community Structure ◽

Plant Community ◽

Plant Communities ◽

Invasive Plants ◽

Effect Size ◽

Meta Analysis ◽

Plant Community Structure ◽

Native Plant ◽

Forage Species ◽

Negative Effect

AbstractIntroducing exotic forages in the attempt to enhance livestock and wildlife forage has been practiced widely for over a century. These forage species are selected for traits conferring persistence under stress, potentially yielding invaders that transform native plant communities. Using standardized systematic review guidelines and meta-analytical techniques we quantified effects of exotic forage invasion on change of native plant community structure, and compared the magnitude and direction of change across exotic forage species, plant functional groups, and structure of plant communities. Our study of 13 exotic forage species in North America (six C4 grasses, three C3 grasses, and four legumes) yielded 35 papers with quantitative data from 64 case studies. Nine of the 13 species met our inclusion criteria for meta-analysis. The overall effect of exotic forage invasion on native plant communities was negative (Ē̄ = −0.74; 95% confidence interval [CI]: −0.29 to −0.25). The effect size was most negative for two C4 grasses, Lehmann lovegrass and Old World bluestems. A negative effect was also expressed by C3 and C4 grass functional groups, and these effects were stronger than for legumes. Effect size differed among measures of plant community structure, with the greatest negative effect on native plant biomass and the least negative effect on species evenness. Weighted fail-safe numbers indicated publication bias was not an issue. Exotic forage species are important for agricultural production but may threaten complex multi-functioning landscapes and should be considered as a subset of potentially invasive exotic species. Characteristics making exotic forages different from other exotic plants hinge on pathways of selection and dispersion: selection is based on persistence mechanisms similar to characteristics of invasive plants; dispersion by humans is intentional across expansive geographic regions. Exotic forages present a complex socio-ecological problem exacerbated by disconnected scientific disciplines, competing interests between policy and science, and organized efforts to increase food production.

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The impact of multiple species invasion on soil and plant communities increases with invader diversity

10.1101/2021.04.30.442106 ◽

2021 ◽

Author(s):

Dusanka Vujanovic ◽

Gianalberto Losapio ◽

Stanko Milic ◽

Dubravka Milic

Keyword(s):

Invasive Species ◽

Invasive Plants ◽

Plant Diversity ◽

Invasive Plant ◽

Single Species ◽

Soil Conditions ◽

Native Plant ◽

Multiple Invasions ◽

Native Plant Diversity ◽

The Impact

Despite increasing evidence indicating that invasive species are harming ecological systems and processes, impacts of multiple invasions, and the linkages between these events and changes in vegetation and soil are inadequately documented and remain poorly understood. Addressing multiple invasions would help to highlight high priority invaders and would aid in designing more effective control strategies, contributing to environmental restoration and sustainability. In this work, we tested the impact of three concurring invasive plant species, Amorpha fruticosa, Fraxinus pennsylvanica and Acer negundo, on soil conditions and native plant diversity. The research was conducted in riparian ecosystem and included the following treatments: (1) co-occurrence of the three invasive plant species, (2) occurrence of a single invasive species, and (3) control, i.e., absence of invasive species. Our findings revealed that the impact of invasive plants on soil properties and native plant diversity is magnified by their co-occurrence. Soil in mixed plots (those populated with all three invaders) contained much higher levels of nitrifying bacteria (NB), organic matter (Om), nitrogen (N), and carbon (C) as well as lower carbon to nitrogen ratio (C:N) levels, compared to single species invaded plots and control plots. Mixed plots were also characterized by reduced native plant diversity compared to single species invaded and control plots. Differences in soil conditions and native plant diversity revealed the interactive potential of invasive plants in depleting biodiversity, and thus in affecting ecological and biogeochemical processes. Our results highlight the need to study the impact of multispecies invasion and suggest that sites in riparian areas affected by co-occurring invaders, should be prioritized for ecosystem restoration. Keywords: Acer negundo, Amorpha fruticosa, Fraxinus pennsylvanica, invasive plants, multiple invasions, soil properties

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