Effects of Glyphosate Application on Physiologically Integrated Clones of the Invasive Plant Carpobrotus edulis

Management of invasive alien species is a high priority for biodiversity conservation. Here, we studied the effects of glyphosate application, at 0.06 g/m2 concentration, on physiologically integrated basal and apical ramets of the invasive clonal plant Carpobrotus edulis. Physiological integration allows the transport of resources and other substances between connected ramets in clonal plants. We found a significant reduction of growth and photochemical efficiency both in basal and apical ramets of C. edulis after glyphosate application. Interestingly, we also observed a significant growth reduction in untreated basal ramets when they remained connected to apical ramets treated with glyphosate. This result was interpreted as a cost for basal ramets due to supporting severely stressed apical ramets. Therefore, local application of glyphosate to apical ramets of C. edulis can negatively affect not only their own growth, but also the growth of their interconnected, untreated basal ramets. Our results suggest that glyphosate effectiveness can be maintained when applied only to one part of the clone so that the amount of herbicide used in eradication programs can be greatly reduced, which can minimize the negative impact of chemical herbicides on ecosystems.

Biosecurity and post-arrival pathways in New Zealand: relating alien organism detections to tourism indicators

Between-country tourism is established as a facilitator of the spread of invasive alien species; however, little attention has been paid to the question of whether tourism contributes to the arrival and subsequent dispersal of exotic organisms within national borders. To assess the strength of evidence that tourism is a driver for the accidental introducing and dispersal of exotic organisms, we sourced three national databases covering the years 2011 to 2017, namely international and domestic hotel guest nights and national population counts, along with records of exotic organism detections collected by the Ministry for Primary Industries, New Zealand’s government agency that oversees biosecurity. We fitted statistical models to assess the strength of the relationship between monthly exotic organism interception rate, guest nights and population, the latter as a baseline. The analysis showed that levels of incursion detection were significantly related to tourism records reflecting the travel of both international and domestic tourists, even when population was taken into account. There was also a significant positive statistical correlation between the levels of detection of exotic organisms and human population. The core take-home message is that a key indicator of within-country human population movement, namely the number of nights duration spent in specific accommodation, is statistically significantly correlated to the contemporaneous detection of exotic pests. We were unable to distinguish between the effects of international as opposed to domestic tourists. We conclude that this study provides evidence of impact of within-country movement upon the internal spread of exotic species, although important caveats need to be considered.

Forest canopy resists plant invasions: a case study of Chromolaena odorata in Sal (Shorea robusta) forests of Nepal

Invasive alien species are a major threat to global biodiversity due to the tremendous ecological and economic damage they cause in forestry, agriculture, wetlands, and pastoral resources. Understanding the spatial pattern of invasive alien species and disentangling the biophysical drivers of invasion at the forest stand level is essential for managing forest ecosystems and the wider landscape. However, forest-level and species-specific information on Invasive Alien Plant Species (IAPS) abundance and their spatial extent are largely lacking. In this context, we analysed the cover of one of the world’s worst invasive plants, Chromolaena odorata, in Sal (Shorea robusta) forest in central Nepal. Vegetation was sampled in four community forests using 0.01 ha square quadrats, covering the forest edge to the interior. C. odorata cover, floral richness, tree density, forest canopy cover, shrub cover, tree basal area, and disturbances were measured in each plot. We also explored forest and IAPS management practices in community forests. C. odorata cover was negatively correlated with forest canopy cover, distance to the road, angle of slope, and shrub cover. Tree canopy cover had the largest effect on C. odorata cover. No pattern of C. odorata cover was seen along native species richness gradients. In conclusion, forest canopy cover is the overriding biotic covariate suppressing C. odorata cover in Sal forests.

A framework for improving understanding of volunteers' motivations to monitor and control invasive alien species

Citizens make an important contribution to the study and management of biological invasions, as many monitoring and control projects rely heavily on volunteer assistance. Understanding the reasons why people participate in such projects is critical for successful recruitment and retention of volunteers. While research attention for this topic is growing, it is published in journals from different disciplines. We used a meta-synthesis approach to extract, analyze and synthesize the available information from 28 selected studies investigating motivations of volunteers to engage in monitoring and control of invasive alien species (IAS). Our findings show how motivations fit three broad themes, reflecting environmental concerns, social motivations, and personal reasons. An important outcome of this study is the description of motivations that are unique to the IAS context: supporting IAS management, protecting native species and habitats, and livelihood/food/income protection or opportunities. In addition, our study reflects on important methodological choices for investigating volunteer motivations as well as ethical issues that may arise in practice. We conclude with a set of recommendations for project design and future research on volunteer motivations in IAS contexts, emphasizing the importance of collaboration with social scientists.

Legal Regulation of Invasive Alien Species with Regards to Climate Change in Ukraine

The present paper is devoted to the problems of legal regulation of protecting biological diversity from the harmful effects of invasive alien species (hereinafter, IAS) with regards to climate change. Taking into consideration the fact that one of the main principles of environmental protection is the preservation of spatial and species diversity, legal understanding of the interconnectedness between climate change and harmful biological influences, is of great scientific and practical significance. Notably, the protection of the environment from the adverse effects of IAS and climate change is interconnected with the conservation and sustainable use of biological resources, as stated by the provisions of the Convention on Biological Diversity (Rio de Janeiro, 1992) and its protocols and decisions. Thus, one should acknowledge that climate change and invasive alien species are not only two of the key threats to biodiversity, but are directly interrelated and can act synergistically, presenting additional pressure for conservation and sustainability. Meanwhile, current legal regulation of both, climate change and IAS is relatively new to Ukrainian legislation, mostly done by means of international legal instruments. The existing national legal acts are generally of a strategic nature and address these issues separately with few legal provisions mentioning their interconnection. The paper substantiates the need to acknowledge and legally define the interrelation between climate change and invasive alien species. Thus, the development of appropriate regulatory framework for prevention and control of IAS should be carried out with consideration of climate change issues. In turn, national environmental legislation, in particular national framework law ‘On Environmental Protection’ as well climate change policy and laws should be complemented by provisions incorporating IAS management as a tool for reducing pressure on ecological services and enhancing ecosystem resilience.

Management of invasive alien species in Spain: A bibliometric review

Scientific and grey literature on invasive alien species (IAS) is conditioned by social, economic and political priorities, editorial preferences and species and ecosystem characteristics. This leads to knowledge gaps and mismatches between scientific research interests and management needs. We reviewed the literature on IAS management in Spain found in Scopus, Web of Science, Google Scholar and Dialnet to identify key deficiencies and priority research areas. The collected literature was classified, employing features describing formal aspects and content. We used bibliometric and keyword co-occurrence network analyses to assess the relationship between features and reveal the existence of additional topics. Most of the compiled documents (n = 388) were focused on terrestrial ecosystems and inland waters, whereas marine and urban ecosystems were under-represented. The literature was largely generic and not species-specific, focusing on raising awareness and proposing changes on current regulation as prominent approaches to prevent further introductions. The compiled authors exhibited many clear publishing preferences (e.g. language or document type), but less regarding target taxa. In addition, there was a strong association between species and the different features considered, especially between the methodological approach (e.g. review, field experiment) and the primary emphasis of study (i.e. basic/theoretical, applied or interdisciplinary). This indicates that research on IAS has had a strong species-specific focus. References about terrestrial species focused mainly on vascular plants, whereas references about inland waters were mostly on fishes and the giant reed (Arundo donax), which has been managed with partial success. Animal culling and plant removal were the most frequent eradication and small-scale control treatments, whereas the documents addressing wider spatial scales were largely theoretical. Consequently, the success of described treatments was largely uncertain. Spanish invasion science research has been occasionally innovative, incorporating novel technologies (e.g. species distribution modelling) and engaging society with citizen-science approaches. However, the ratio between basic/theoretical and applied studies indicates that more applied research/management is needed, especially in inland waters and marine ecosystems. We call for increasing effort in the effective dissemination of experience in IAS management to enhance current practical knowledge, including that of schemes undertaken by public agencies.

Public Awareness and Perceptions of Invasive Alien Species in Small Towns

Invasive alien species (IAS) are a growing threat globally and cause a variety of ecological, economic, and social impacts. People can introduce IAS and facilitate their spread, and can also implement, support, or oppose their management. Understanding local knowledge, awareness, and perceptions are therefore crucial if management and policy are to be effective. We administered questionnaires to members of the public in eight small towns along the Berg River Catchment in the biodiverse fynbos biome of South Africa. We aimed to assess: (1) awareness of IAS by the general public, (2) local perceptions of the impacts associated with IAS, (3) whether awareness of IAS is correlated with demographic covariates and IAS density, and (4) people’s willingness to detect, report, and support IAS management. Overall, 262 respondents participated in the survey. Most respondents (65%) did not know what IAS are, and 10% were unsure. Many respondents also perceived IAS as beneficial. Using a logistic regression, we found that IAS density, educational level, and gender influenced people’s knowledge and perceptions about IAS in the region. There were a small number (4%) of respondents currently detecting and reporting IAS, but many respondents were interested to learn more. We concluded that people living in small towns in the Western Cape of South Africa remain largely unaware of IAS and their impacts. It is crucial to increase awareness-raising initiatives, and build support and engagement in management of IAS in small towns.