Explaining the variation in impacts of non-native plants on local-scale species richness: the role of phylogenetic relatedness

Aim: To assess how the magnitude of impacts of non-native plants on species richness of resident plants and animals varies in relation to the traits and phylogenetic position of the non-native as well as characteristics of the invaded site.Location: Global.Methods: Meta-analysis and phylogenetic regressions based on 216 studies were used to examine the effects of 96 non-native plant species on species richness of resident plants and animals while considering differences in non-native species traits (life-form, clonality or vegetative reproduction, and nitrogen-fixing ability) and characteristics of the invaded site (ecosystem type, insularity and climatic region).Results: Plots with non-native plants had lower resident plant (–20.5%) and animal species richness (–26.4%) than paired uninvaded control plots. Nitrogen-fixing ability, followed by phylogeny and clonality were the best predictors of the magnitude of impacts of non-native plants on native plant species richness. Non-nitrogen-fixing and clonal non-native plants reduced species richness more than nitrogen-fixing and non-clonal invaders. However, life-form and characteristics of the invaded sites did not appear to be important. In the case of resident animal species richness, only the phylogenetic position of the non-native and whether invaded sites were islands or not influenced impacts, with a more pronounced decrease found on islands than mainlands.Main conclusions: The presence of a phylogenetic signal on the magnitude of the impacts of non-native plants on resident plant and animal richness indicates that closely related non-native plants tend to have similar impacts. This suggests that the magnitude of the impact might depend on shared plant traits not explored in our study. Our results therefore support the need to include the phylogenetic similarity of non-native plants to known invaders in risk assessment analysis

Native fruit traits may mediate dispersal competition between native and non-native plants

Seed disperser preferences may mediate the impact of invasive, non-native plant species on their new ecological communities. Significant seed disperser preference for invasives over native species could facilitate the spread of the invasives while impeding native plant dispersal. Such competition for dispersers could negatively impact the fitness of some native plants. Here, we review published literature to identify circumstances under which preference for non-native fruits occurs. The importance of fruit attraction is underscored by several studies demonstrating that invasive, fleshy-fruited plant species are particularly attractive to regional frugivores. A small set of studies directly compare frugivore preference for native vs. invasive species, and we find that different designs and goals within such studies frequently yield contrasting results. When similar native and non-native plant species have been compared, frugivores have tended to show preference for the non-natives. This preference appears to stem from enhanced feeding efficiency or accessibility associated with the non-native fruits. On the other hand, studies examining preference within existing suites of co-occurring species, with no attempt to maximize fruit similarity, show mixed results, with frugivores in most cases acting opportunistically or preferring native species. A simple, exploratory meta-analysis finds significant preference for native species when these studies are examined as a group. We illustrate the contrasting findings typical of these two approaches with results from two smallscale aviary experiments we conducted to determine preference by frugivorous bird species in northern California. In these case studies, native birds preferred the native fruit species as long as it was dissimilar from non-native fruits, while non-native European starlings preferred non-native fruit. However, native birds showed slight, non-significant preference for non-native fruit species when such fruits were selected for their physical resemblance to the native fruit species. Based on our review and case studies, we propose that fruit characteristics of native plant communities could dictate how well a non-native, fleshy-fruited plant species competes for dispersers with natives. Native bird preferences may be largely influenced by regional native fruits, such that birds are attracted to the colors, morphology, and infructescence structures characteristic of preferred native fruits. Non-native fruits exhibiting similar traits are likely to encounter bird communities predisposed to consume them. If those non-natives offer greater fruit abundance, energy content, or accessibility, they may outcompete native plants for dispersers

Regional Invasive Species & Climate Change Management Challenge: Why Native? Benefits of planting native species in a changing climate

Yards host a variety of native and non-native plants. It is easy to assume all plants play a similar role in supporting wildlife, but native plants dramatically increase the diversity of bees, butterflies, birds and other native animals. Additionally, non-native plants can become invasive or support invasive pests. Native plants increase biodiversity and reduce risks associated with invasive species, which supports resilient ecosystems in the face of climate change

The role of non-native plants in the integration of non-native phytophagous invertebrates in native food webs

This thesis brings together a series of studies, examining the role of non-native plants in the integration of non-native invertebrates in native food webs. I use data from comprehensive surveys of formally-planted gardens to investigate the efficacy of straightforward measures of non-native plant presence and/or landscape parameters, as reliable predictors of non-native invertebrate presence, finding that non-native invertebrate richness increases with non-native plant species richness, with invertebrates showing a clear preference for woody plants. I then use the context of metapopulation theory to explore the facilitative role of non-native plants in the ability of a non-native invertebrate to persist within a community, finding that where host-plant habitat patches are closer together, the likelihood of a patch being occupied is greater, especially if the patch is occupied but that this effect is not universal, with species-specific effects present also. I then explore the potential for apparent competition, in the form of negative indirect interactions between native and non-native plants mediated by a shared invertebrate enemy, with the indirect interactions biased by plant relatedness, finding that phylogenetically ranked pairwise native/non-native plant interactions are weakly correlated with observed shared invertebrate interactions, while a significant Mantel test result indicates a significant potential for apparent competition. Finally, I test for detectability of apparent competition in a gall wasp community, finding no evidence of apparent competition but potential evidence for the unexpected occurrence of apparent mutualism. Collectively, these findings provide original insight into how non-native plants and non-native invertebrates interact in an ecological community, and how these interactions help to structure the community. Additionally, they have implications for non-native invertebrate species management, from the practical application of ground-level planting decisions to the development of reliable predictive tools

First record of Heptapleurum arboricola Hayata (Araliaceae) as a casual non-native woody plant in the Mediterranean area

I report here the first record of Heptapleurum arboricola Hayata (syn. Schefflera arboricola (Hayata) Merr.) (Araliaceae) as a casual non-native plant throughout the Mediterranean area. I observed the natural regeneration in urban areas at Castellammare del Golfo, a small coastal town in north-west Sicily (Mediterranean Italy). Due to the lack of self-sustaining populations and the short-term observational period, Heptapleurum arboricola should be considered as a casual species according to the classification of non-native plants. The detection of early signs of naturalization of non-native plants is of crucial importance for the management and control of invasive species. The main abiotic and biotic factors involved in the possible future spread of the species are briefly discussed

Going up the Andes: patterns and drivers of non-native plant invasions across latitudinal and elevational gradients

The Andes mountain range in South America has a high level of endemism and is a major source of ecosystem services. The Andes is increasingly threatened by anthropogenic disturbances that have allowed the establishment of non-native plants, mainly in the lower elevation areas. However, synergies between climate change and anthropogenic pressure are promoting the spread of non-native plants to higher elevation areas. In this article, we evaluate and identify the main non-native plants invading Andean ecosystems, and assess their taxonomic families, growth forms and distribution patterns. Based on a systematic literature review, we identified the importance of climatic and anthropogenic factors as drivers of non-native species establishment in Andean ecosystems and the main impacts of non-native plants in the Andes. We then identified research gaps across each biogeographic region in the Andes. Finally, we highlight key elements to better tackle the problem of non-native plant invasions in Andean ecosystems, including the need for a systematic monitoring of invasion patterns and spread (e.g. MIREN protocol) and a common policy agenda across international borders for the prevention and management of non-native plants in this highly vulnerable region.Fil: Fuentes Lillo, Eduardo. Universidad de Concepción; Chile. Universiteit Antwerp; BélgicaFil: Lembrechts, Jonas J.. Universiteit Antwerp; BélgicaFil: Barros, Ana Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Aschero, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Bustamante, Ramiro O.. Universidad de Chile; ChileFil: Cavieres, Lohengrin A.. Universidad de Concepción; ChileFil: Clavel, Jan. Universiteit Antwerp; BélgicaFil: Herrera, Ileana. Universidad Espíritu Santo; EcuadorFil: Jiménez, Alejandra. Universidad de Concepción; ChileFil: Tecco, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Hulme, Philip E.. Lincoln University.; Nueva ZelandaFil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Rozzi, Ricardo. University of North Texas; Estados UnidosFil: García, Rafael A.. Universidad de Concepción; ChileFil: Simberloff, Daniel. University of Tennessee; Estados UnidosFil: Nijs, Ivan. Universiteit Antwerp; BélgicaFil: Pauchard, Aníbal. Universidad de Concepción; Chil

Assessment of Pollinator Preference of Native and Nonnative Perennial Flowering Plants in South Dakota’s Grasslands

With global pollinator decline continually worsening as a result of human action, concerned citizens and scientists alike have been looking for answers as to what can be done to help, and the question of whether native or non-native plants provide more benefit to pollinating insects has been long discussed in the scientific community. This research is intended to help answer that question by attempting to determine whether pollinators have a distinct preference between native and non-native plants when presented with both options. The hypothesis at outset of this project was that native plants would provide greater benefit to pollinators, whom they (presumably) evolved alongside, and would thus be selected more frequently than non-native plants. To test this, a collection of various native and non-native plants was deployed in a restored grassland in rural South Dakota and observed for 10 days. Data collected included abundance of different groups of insect visitors and the frequency at which they visited individual plants. Analysis of data gathered during the study showed that there was no clear preference between plants based on native status alone, but rather that differences in visitation frequency possibly occurred as result of individual differences between the species of plants used, meaning that a variety of factors, not necessarily just native status, should be considered when selecting plants with the intent of encouraging pollinator activity. These results can be interpreted by ecologists to provide guidance for further research questions concerning what morphological and physiological traits attract pollinators and why, as well as conservation-minded members of the general public on what species and varieties of plants may provide the most benefit to pollinators when gardening or landscaping. In addition to the findings associated with the main research question, data also showed that pollinating insects that are not native to the study region dominated observations throughout the duration of the study, which may also have contributed to the study’s findings as well as spark further research on the relative abundance of native vs. non-native pollinators in the study area. This information could help provide more insight on the state of South Dakota’s pollinator populations and allow for more focused interpretation of the results of this study and any others like it

Explaining the variation in impacts of non-native plants on local-scale species richness: the role of phylogenetic relatedness

ABSTRACT Aim To assess how the magnitude of impacts of non-native plants on species richness of resident plants and animals varies in relation to the traits and phylogenetic position of the non-native as well as characteristics of the invaded site. Location Global. Methods Meta-analysis and phylogenetic regressions based on 216 studies were used to examine the effects of 96 non-native plant species on species richness of resident plants and animals while considering differences in non-native species traits (life-form, clonality or vegetative reproduction, and nitrogen-fixing ability) and characteristics of the invaded site (ecosystem type, insularity and climatic region). Results Plots with non-native plants had lower resident plant (-20.5%) and animal species richness (-26.4%) than paired uninvaded control plots. Nitrogenfixing ability, followed by phylogeny and clonality were the best predictors of the magnitude of impacts of non-native plants on native plant species richness. Nonnitrogen-fixing and clonal non-native plants reduced species richness more than nitrogen-fixing and non-clonal invaders. However, life-form and characteristics of the invaded sites did not appear to be important. In the case of resident animal species richness, only the phylogenetic position of the non-native and whether invaded sites were islands or not influenced impacts, with a more pronounced decrease found on islands than mainlands. Main conclusions The presence of a phylogenetic signal on the magnitude of the impacts of non-native plants on resident plant and animal richness indicates that closely related non-native plants tend to have similar impacts. This suggests that the magnitude of the impact might depend on shared plant traits not explored in our study. Our results therefore support the need to include the phylogenetic similarity of non-native plants to known invaders in risk assessment analysis

Explaining the variation in impacts of non-native plants on local-scale species richness: the role of phylogenetic relatedness

ABSTRACT Aim To assess how the magnitude of impacts of non-native plants on species richness of resident plants and animals varies in relation to the traits and phylogenetic position of the non-native as well as characteristics of the invaded site. Location Global. Methods Meta-analysis and phylogenetic regressions based on 216 studies were used to examine the effects of 96 non-native plant species on species richness of resident plants and animals while considering differences in non-native species traits (life-form, clonality or vegetative reproduction, and nitrogen-fixing ability) and characteristics of the invaded site (ecosystem type, insularity and climatic region). Results Plots with non-native plants had lower resident plant (-20.5%) and animal species richness (-26.4%) than paired uninvaded control plots. Nitrogenfixing ability, followed by phylogeny and clonality were the best predictors of the magnitude of impacts of non-native plants on native plant species richness. Nonnitrogen-fixing and clonal non-native plants reduced species richness more than nitrogen-fixing and non-clonal invaders. However, life-form and characteristics of the invaded sites did not appear to be important. In the case of resident animal species richness, only the phylogenetic position of the non-native and whether invaded sites were islands or not influenced impacts, with a more pronounced decrease found on islands than mainlands. Main conclusions The presence of a phylogenetic signal on the magnitude of the impacts of non-native plants on resident plant and animal richness indicates that closely related non-native plants tend to have similar impacts. This suggests that the magnitude of the impact might depend on shared plant traits not explored in our study. Our results therefore support the need to include the phylogenetic similarity of non-native plants to known invaders in risk assessment analysis