Abstract
Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM) approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.
Highlights
The movement of vascular plants across regions has always occurred, primarily with human assistance, and has increased exponentially in recent times with increases in global trade [1,2]
The first list shows those plant taxa that are currently absent from Australia and ranks them by their likelihood of becoming weeds in each of the states or territories should they be introduced
We have applied the self-organising map (SOM) approach to a dataset extracted from a pre-existing global plant database [39] to predict weediness of plant taxa before and after they have been moved to a new region
Summary
The movement of vascular plants across regions has always occurred, primarily with human assistance, and has increased exponentially in recent times with increases in global trade [1,2]. In an attempt to address confusion with the plant naturalization/ invasion process, Richardson et al [4] made a solid attempt to better define the terminology employed. According to these authors the terms weed and invasive plant are not interchangeable, because the latter does not infer any environmental and economic impact. This proposed terminology has not been widely applied and confusion continues to abound in the literature. Large sums of money are invested worldwide to manage them (e.g. [8,9,10]) and there is increasing interest in identifying potential major weeds of the future and managing them early [11,12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
