Prioritizing terrestrial invasive alien plant species for management in urban ecosystems

Abstract

1. Invasive alien plant species (IAPs) in urban areas can have detrimental effects on biodiversity, ecosystem services and human well-being. Urban areas are complex social management mosaics with high land-use diversity, complex land tenure patterns and many different stakeholder groups, some of which derive benefits from invading species. Urban conservation practitioners face complex decisions about which IAPs require management. Yet most IAPs prioritization frameworks have been designed for and implemented in natural or rural areas and are generally inadequate for guiding effective and sustainable interventions in urbanized areas.2. We modified an existing prioritization scheme to develop a framework for prioritizing terrestrial IAPs in urban areas which applies evidence-based (data-driven) and stakeholder-based (local knowledge) assessments to score and rank alien plant species in terms of their priority for management using an objective set of criteria.3. The framework consists of 46 criteria, grouped into eight modules which assess invasion status, habitat requirements, biological characteristics, dispersal ability, distribution, impacts (positive and negative) and potential for control for each alien plant species under consideration. 4. We use the city of Toronto, Canada as a case study to test our framework-a list of 50 IAPs were effectively scored and ranked in order of high to low priority for control. Species with the highest total prioritization scores were Vincetoxicum rossicum (Dog Strangling Vine), Convolvulus arvensis (Field Bindweed) and Taraxacum officinale (Common Dandelion, ranked 1, 2 and 3 respectively).5. Many of the identified high priority species align with those previously flagged as of management concern by conservation practitioners, but also include those that are not actively managed due to their perceived lower ecological impacts.These species still require high resource investment for other objectives such as aesthetics. This highlights the complexity of alien plant species management in urban areas.6. Synthesis and applications. Prioritizing invasive alien plants for management in urban areas is particularly challenging due to often conflicting ecological, economic and social objectives. We use available evidence and local stakeholder knowledge to develop an objective and systematic prioritization tool which can | 873

Prioritizing sites for terrestrial invasive alien plant management in urban ecosystems

“…To illustrate this, we mapped the distribution of one of the Toronto region's most widespread invasive alien species, Vincetoxicum rossicum (dog‐strangling vine; Livingstone et al., 2020; Sodhi et al., 2019). This species was identified as the highest management priority in a recent assessment of the Toronto region's 50 most widespread terrestrial alien plant species (Potgieter et al., 2021). Native to Ukraine and south‐western Russia, V. rossicum has a significant impact on biodiversity and ecosystem functioning (supporting and regulating ecosystem services; sensu MEA, 2005) by out‐competing native plant species (e.g.…”

“…Integrating biodiversity conservation, the provision of ecosystem services and social trade‐offs into a comprehensive management strategy is a key challenge in prioritizing invaded sites in urban areas (Cilliers et al., 2012). Pragmatic approaches for setting IAP management priorities are required in these complex socio‐ecological landscapes (Epanchin‐Niell et al., 2010) and need to be transparent, repeatable and defensible (Hiebert & Stubbendieck, 1993; Potgieter et al., 2021; Randall et al., 2008; Warner et al., 2003).…”

“…Integrating biodiversity conservation, the provision of ecosystem services and social trade-offs into a comprehensive management strategy is a key challenge in prioritizing invaded sites in urban areas (Cilliers et al, 2012). Pragmatic approaches for setting IAP management priorities are required in these complex socio-ecological landscapes (Epanchin-Niell et al, 2010) and need to be transparent, repeatable and defensible (Hiebert & Stubbendieck, 1993;Potgieter et al, 2021;Randall et al, 2008;Warner et al, 2003). McGeoch et al (2016) argue that any comprehensive and strategic approach to prioritization must include three complementary foci that together enable effective prioritization: (1) invasive species, (2) pathways of invasion and (3) sites with a high risk of invasion and of high biodiversity value.…”

Quantifying and linking mechanism scenarios to invasive species impact

“…Not only is it scale independent, but also the framework presented here aligns with other concepts of impact, while providing mechanistic inferences underpinning different modes and magnitudes of impact. This framework can provide a quantitative ranking for management prioritization tools that use available information to prioritize NIS for management actions (Potgieter, Shrestha, & Cadotte, 2022; Robertson et al, 2003). The commonly employed impact scheme, the International Union for Conservation of Nature (IUCN's) EICAT (Blackburn et al, 2014; Hawkins et al, 2015), classifies NIS into impact categories that range from Minor to Massive (for more details see Hawkins et al, 2015).…”

Beyond values: How emotions, anthropomorphism, beliefs and knowledge relate to the acceptability of native and non‐native species management in cities

“…Yet, while Shackleton et al (2019) referred to ‘perception’ as an interdisciplinary umbrella for other, more specific constructs, we were particularly interested in the construct ‘acceptability of management actions’. Management actions can range from unspecified control actions and prevention to eradication including manual removal or herbicide use for invasive plants in a person's own backyard to methods such as insecticide‐treated prey or trap‐neuter‐release methods for, for example, domestic cats (Potgieter et al, 2022). Management actions can also simply imply leaving species at their location without doing anything.…”