Motivation The database initiated by the Mountain Invasion Research Network (MIREN) is one of the few globally implemented standardized vegetation surveys in mountains. The focus is on collecting plant species occurrences at 5‐year intervals along and adjacent to mountain roads spanning elevational gradients, with the goal of providing critical information about the ongoing spread of non‐native plants and the potential impacts...

The cumulative ecological risk from invasions is assumed to increase as more species invade. However, we propose that cumulative risk can saturate when multiple, functionally similar species are present, limiting the marginal contribution of newcomers. We explored this idea by quantifying the spatial footprint of climatic suitability for 12 fire-promoting grasses in Hawaii using species distribution models, using the total cli...

Aim Understanding invasion trends is essential for mitigating the impacts of invasive species, yet their quantification is easily affected by temporal biases. Previous research has identified biases introduced by inadequate field surveying (delayed detection) but has overlooked the time between a species' detection and the communication of that detection in status reports, databases, or checklists –time delays we refer to as d...

Aim Mountain ecosystems are experiencing increased invasion of non‐native plants. These increases in non‐native species put mountains at risk of biotic homogenisation and a reduction of biodiversity. Our study aims to test if non‐native plant species are contributing to biotic homogenisation along roadways in mountain regions and how this changes along elevation gradients and across spatial scales. Location 18 globally distrib...

Globally, invasive plant-fueled wildfires have tremendous environmental, economical, and societal impacts, and the frequencies of wildfires and plant invasions are on an upward trend globally. Identifying which plant species tend to increase the frequency or severity of wildfire is important to help manage their impacts. We developed a screening system to identify introduced plant species that are likely to increase wildfire r...

Aim Biological invasions are likely determined by species dispersal strategies as well as environmental characteristics of a recipient region, especially climate and human impact. However, the contribution of climatic factors, human impact, and dispersal strategies in driving invasion processes is still controversial and not well embedded in the existing theoretical considerations. Here, we study how climate, species dispersal...

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrast...

Plant‐herbivore interactions have been predicted to play a fundamental role in plant invasions, although support for this assertion from previous research is mixed. While plants may escape from specialist herbivores in their introduced ranges, herbivory from generalists is common. Tolerance traits may allow non‐native plants to mitigate the negative consequences of generalist herbivory that they cannot avoid in their introduce...

Aim Niche‐based species distribution models (SDMs) are commonly used to predict impacts of global change on biodiversity, but the reliability of these predictions in space and time depends on their transferability. We tested how the strategy used to choose predictors impacts the transferability of SDMs at a cross‐continental scale. Location North America, Eurasia and Australia. Method We used a systematic approach including 50...

Aim We evaluated whether the performance of individuals and populations of the invasive plant Verbascum thapsus differs between its native and non‐native ranges, across climate gradients, and in response to its position in a global‐scaled niche model. Location India (Kashmir) and Switzerland (native range) and Australia and USA (Hawaii, Montana and Oregon) (non‐native range). Methods We measured population characteristics (den...

Aim Non‐native species are being distributed globally as a result of human actions, but we still know little about emerging biogeographical patterns. We tested whether the distribution of plant invaders across tropical oceanic islands has a nested structure, and identified mechanisms to explain nestedness among invaders and islands. Location Tropical islands world‐wide. Methods We analysed two datasets: a global one (350 sperm...

Aim To investigate how species richness and similarity of non‐native plants varies along gradients of elevation and human disturbance. Location Eight mountain regions on four continents and two oceanic islands. Methods We compared the distribution of non‐native plant species along roads in eight mountainous regions. Within each region, abundance of plant species was recorded at 41–84 sites along elevational gradients using 100...