Drivers of risk perceptions about the invasive non-native plant Japanese knotweed in domestic gardens

Abstract

How people perceive risks posed by invasive non-native plants (INNP) can influence attitudes and consequently likely influence behavioural decisions. Although some drivers of risk perception for INNP have been identified, research has not determined those for INNP in domestic gardens. This is concerning as domestic gardens are where people most commonly encounter INNP, and where impacts can be particularly acute. Using a survey approach, this study determined the drivers of perceptions of risk of INNP in domestic gardens and which risks most concern people. Japanese knotweed Fallopia japonica, in Cornwall, UK, where it is a problematic INNP in domestic gardens, was used as a case study. Possible drivers of risk were chosen a priori based on variables previously found to be important for environmental risks. Participants perceived Japanese knotweed to be less frequent on domestic property in Cornwall if their occupation involved the housing market, if they had not had Japanese knotweed in their own garden, if they did not know of Japanese knotweed within 5 km of their home, or if they were educated to degree level. Participants who thought that the consequences of Japanese knotweed being present on domestic property could be more severe had occupations that involved the housing market, knew of Japanese knotweed within 5 km of their home, or were older. Although concern about the damage Japanese knotweed could do to the structure of a property was reported as the second highest motivation to control it by the majority of participants, the perception of threat from this risk was rated as relatively low. The results of this study have implications for policy, risk communication, and garden management decisions. For example, there is a need for policy that provides support and resources for people to manage INNP in their local area. To reduce the impact and spread of INNP we highlight the need for clear and accurate risk communication within discourse about this issue. The drivers identified in this study could be used to target awareness campaigns to limit the development of over-or under-inflated risk perceptions.

Domestic gardens play a dominant role in selecting alien species with adaptive strategies that facilitate naturalization

“…Moreover, with the increase in e‐commerce, plants, including many potentially or known invasive species, can be bought from almost any place on Earth (Humair, Humair, Kuhn, & Kueffer, ). The management of domestic gardens is rarely regulated and depends largely on an individual owner’s experience and interests (Loram, Warren, Thompson, & Gaston, ; Robinson, Inger, & Gaston, ; but see a recent study on identifying potential invasive plants based on gardeners’ knowledge in Great Britain; Dehnen‐Schmutz & Conroy, ). Compared to alien species introduced through other pathways, species cultivated in ornamental gardens are usually introduced and become naturalized earlier (van Kleunen et al, ; Pyšek, Sádlo, Mandák, & Jarošík, ).…”

Public preferences for the management of different invasive alien forest taxa

“…), perceived threat from IAS (Fischer and Charnley 2012), emotional factors (Shackleton et al 2019a), economic impacts (McDermott et al 2013; Shackleton et al 2019b), IAS ecology/biology (Garcia-Llorente et al 2008;Robinson et al 2017;Shackleton et al 2007;Shrestha et al 2019) and finally to clear and consistent communication by relevant organizations(Mackenzie and Larson 2010;Porth et al 2015)…”