Integrating invasive species policies across ornamental horticulture supply-chains to prevent plant invasions

1.Ornamental horticulture is the primary pathway for invasive alien plant introductions. We critically appraise published evidence on the effectiveness of four policy instruments that tackle invasions along the horticulture supply chain: pre-border import restrictions, post-border bans, industry codes of conduct and consumer education. 2.Effective pre-border interventions rely on rigorous risk assessment and high industry compliance. Post-border sales bans become progressively less effective when alien species become widespread in a region. 3.A lack of independent performance evaluation and of public disclosure, limits the uptake and effectiveness of voluntary codes of conduct and discourages shifts in consumer preference away from invasive alien species. 4.Policy implications. Closing the plant invasion pathway associated with ornamental horticulture requires government-industry agreements to fund effective pre- and post-border weed risk assessments that can be subsequently supported by widely adopted, as well as verifiable, industry codes of conduct. This will ensure producers and consumers make informed choices in the face of better targeted public education addressing plant invasions

Working with gardeners to identify potential invasive ornamental garden plants – testing a citizen science approach

The introduction and use of ornamental plants in gardens is the main pathway for plant invasions globally. High numbers of ornamental plants in gardens may not have started an invasion process yet and are a risk for possible future invasions. Gardeners could be among the first to notice plant traits that have also been recognised to contribute to the potential risk of ornamental plants to escape from cultivation. We asked gardeners in Britain to report ornamental plants that were spreading within their gardens and difficult to control using an online survey. Gardeners submitted 201 records of 121 species of which 104 are non-native in Britain. Most non-native species reported were already recorded and wide-spread in Britain outside cultivation, but about a third are not widely distributed, and eight species are not known outside cultivation. Gardeners’ control efforts were mainly directed to confine plants from further spread, but they also tried to eradicate many of the reported plants. Our results provide evidence that gardeners’ knowledge could help to identify potentially problematic invasive plants early in the invasion process. Even with low levels of participation all evidence collected would be very valuable in official risk management procedures as well as supporting legal obligations on early detection, surveillance and monitoring. At the same time, however, raising awareness of the problem by actively collaborating with gardeners could be of equal importance for the prevention of ornamental plant invasions in the future

Seven recommendations to make your invasive alien species data more useful

Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost

Crossing Frontiers in Tackling Pathways of Biological Invasions

Substantial progress has been made in understanding how pathways underlie and mediate biological invasions. However, key features of their role in invasions remain poorly understood, available knowledge is widely scattered, and major frontiers in research and management are insufficiently characterized. We review the state of the art, highlight recent advances, identify pitfalls and constraints, and discuss major challenges in four broad fields of pathway research and management: pathway classification, application of pathway information, management response, and management impact. We present approaches to describe and quantify pathway attributes (e.g., spatiotemporal changes, proxies of introduction effort, environmental and socioeconomic contexts) and how they interact with species traits and regional characteristics. We also provide recommendations for a research agenda with particular focus on emerging (or neglected) research questions and present new analytical tools in the context of pathway research and managemen

Greater focus needed on alien plant impacts in protected areas

Alien plants pose significant threats to protected areas worldwide yet many studies only describe the degree to which these areas have become invaded. Research must move toward a better understanding of alien plant impacts since managers urgently require an appropriate evidence base to prioritize control/eradication targets. We analyze a global database of quantitative studies of alien plant impacts to evaluate existing knowledge of alien plant impacts within and outside protected areas. Although protected areas are a significant focus for quantitative impact studies, the biogeographic emphasis of most research effort does not coincide with the global distribution of protected areas nor the plant species or life-forms recognized to have greatest impacts on ecosystems. While impacts were often as significant within protected areas as outside, only a minority of studies provide any subsequent management recommendations. There is therefore considerable scope to improve the evidence base on alien plant management in protected areas

Blurring alien introduction pathways risks losing the focus on invasive species policy

The pathways by which alien species are introduced to new regions fall into six broad classes: deliberate release; escape from captivity; contaminant of a commodity; stowaway on a transport vector; via an infrastructure corridor (without which spread would not be possible) or unaided from other invaded regions (Hulme et al. 2008). However, Gilroy et al. (2016) argue that species dispersing naturally, through the infrastructure corridor or unaided pathway, should be classed as native rather than alien. We contend their proposal is not only unworkable but also unwise

From West to East and back again: Trans-Siberian Railway as a continental pathway of plant invasions

The rapid increase of invasions worldwide is associated with the intensification and expansion of trade and transport, and access to new source species pools. The presented project contributes to understanding the role of human-mediated pathways (based on the model system of Trans-Siberian railway, Транссибирская магистраль, Transsibirskaya magistral, TSR) in translocating plant species, elucidating the biogeographic patterns of their spread, and predicting the invasion risk of alien species along TSR in the futur

From west to east and back again: Trans-siberian railway as a continental pathway of plant invasions; project overview

We aim at studying the transported plant species and biogeographical patterns of their spread. The project also aims to predict the invasion risk of alien species along TSR in the futur