Mountain bikes as seed dispersers and their potential socio-ecological consequences

Effect of the COVID-19 pandemic on the popularity of protected areas for mountain biking and hiking in Australia: Insights from volunteered geographic information

Although the popularity of protected areas for recreation has been increasing, short term changes in visitation occurred during the COVID-19 pandemic. To examine how volunteer geographic information data can be used to monitor such often rapid changes in visitation across multiple locations, data from online fitness platforms for mountain biking (Trailforks) and remote area hiking (Wikiloc) were analysed before (2019) and during (2020-2021) the COVID-19 pandemic for 40 protected areas in Queensland, Australia. Mountain biking was popular with a total of 93,311 routes on Trailforks, with 26,936 routes in 2019, increasing to 37,406 in 2020, and then decreasing to 28,969 in 2021. Approximately 66% of all the routes were from just three urban protected areas out of the 12 with route data. There were 4367 routes for remote area hiking on Wikiloc across 36 protected areas, which increased slightly from 1081 in 2019, to 1421 in 2020 and to 1865 in 2021. Across 18 factors, distance from urban areas and networks of mountain biking trails best predicted popularity for mountain biking based on Generalised Linear Models. In contrast, average slope and large networks of hiking trails best predicted hiking, with similar results for each year. The two sources of online data were correlated with trail counter data, although not consistently. The results highlight how external factors affect visitation, but also how the same types of protected areas remained popular, and that the impacts of COVID-19 pandemic on visitation in South-East Queensland protected areas was less dramatic than for other regions. This study further highlights how volunteered geographic information can be used to assess the popularity of protected areas, including in rapidly changing conditions.

Management implications

Rapid changes in visitation can be challenging to monitor and manage, as occurred with the COVID-19 pandemic. The impacts of the COVID-19 pandemic on mountain biking and hiking and factors predicting protected area popularity were examined across different parks. Visitation increased at different stages of the pandemic, with mountain bikers' preferring urban parks with networks of mountain bike trails while some hikers preferred more remote large parks. Managers can expand on traditional methods of visitor monitoring by using volunteered geographic information to monitor rapid and longer-term trends of visitation to protected areas.

Mountain bike riding and hiking can contribute to the dispersal of weed seeds

Mountain biking and hiking are popular, but both recreational activities can contribute to the unintentional dispersal of seeds including non-native plants that cause environmental harm (e.g. environmental weeds). Addressing the requirement for more information about the ecological impacts of recreational activities, seed dispersal from mountain biking and hiking were compared under different climatic and environmental conditions. Seeds from a range of graminids and forbs were found to attach to the mountain bike, rider and hiker, including environmental weed seeds, on trails and in-field in montane Australia. While the composition of seeds differed between the two activities, no significant differences were found between traits, such as natives or environmental weed, graminids or forbs, perennial or annual, large or small, attachment or no attachment structures, although sample sizes were small. Few seeds attached to the mountain bike, rider or hiker on dry trails, some seeds attached when trails were wet, but more seeds attached when riding/hiking off trail in a field. Cleaning clothing and bikes and avoiding areas with environmental weed seeding could reduce the risk of this type of unintentional human mediated dispersal, but compliance with such measures may be challenging. Given the increasing popularity of mountain biking and the current controversy about the relative impacts of mountain biking in areas of high conservation concern, additional research assessing severity, duration and range of impacts of mountain biking on soil, wildlife, waterways and vegetation is critical.

Disconnection between conservation awareness and outcome: Identifying a bottleneck on non-native species introduction via footwear

Unintentional seed introduction mediated by visitor's clothing and footwear is a major source of biological invasion into natural areas. To effectively avert these unintentional introductions, we must understand the links that connect relevant knowledge and desired outcome (i.e., seeds not carried on visitor's belongings); however, until now, these links have not been examined. Here, we investigated the links among a visitor's knowledge about biological invasion, awareness of biological invasion, behavior to prevent introduction (cleaning footwear), and being a seed carrier to identify a potential bottleneck between visitor knowledge and ecological outcome. In order to achieve this, we conducted a questionnaire survey and soil sampling from the footwear of visitors to an alpine national park. Soil samples (n = 344) were subjected to a germination experiment, and the number of emerged seedlings was recorded for each sample. We observed seedlings emerging from 27 soil samples (7.8 % of visitors; 44 seedlings in total), comprising non-native species. The degree of a visitor's knowledge about biological invasion increased with the increase in the degree of awareness. However, the high degree of awareness was not linked with the actual behavior of cleaning their footwear before the visit, although footwear cleaning effectively reduced the number of emerged seedlings. We found the lack of a clear association between awareness and behavior (cleaning the footwear) to be the bottleneck. We also investigated the major sources of knowledge about human-mediated seed introduction from footwear and found that television was the most important information source. The key to effectively preventing negative impacts on ecosystems caused by the introduction of non-native species could be to revise methods for informing the community, which will help overcome the bottleneck between awareness and behavior.

Tourist vehicle as a selective mechanism for plant dispersal: Evidence from a national park in the eastern Himalaya

It is increasingly recognised that human vehicle may act as a vector to spread species, but research remains sparse to examine vehicle-mediated spread to natural areas, in particular to protected areas by urbanized societies through increasing tourism/recreation traffic. This study assessed the role of tourist vehicle in driving biotic exchange to Laojun Mountain National Park in the eastern Himalaya. A stratified random sampling method was applied to compare plant seeds in muds collected from different vehicles (sedan, SUV and others) entering the park in different seasons (May, August and October) from different regions. Across the 663 mud samples, 3119 seedlings of 124 species germinated which were predominately roadside ruderals and non-native species. The number of vehicle-dispersed flora was found to be correlated with the amount of mud attached on vehicles, with more seed carried by vehicles travelling in autumn, sport utility vehicles and those from local areas. When seed traits were analysed using generalized linear models, vehicles were more likely disperse appendaged and compact seeds, and those released from low-stature plants such as forb or grass. The results highlight the risks of species introduction and homogenization of flora from seeds on tourist vehicles entering protected areas. Strategies like vehicle washing and managing roadside vegetation may help reduce risks from tourism traffic in the eastern Himalayan parks as well as other sensitive ecosystems around the world.

Applying Geomorphic Principles in the Design of Mountain Biking Singletracks: Conceptual Analysis and Mathematical Modeling

Mountain biking, also known as singletracking, is an emerging sector in outdoor recreation activities. Experience shows that although bicycling is considered a low-impact activity, singletracking may have adverse environmental footprints. Here, we review and conceptually analyze the forces applied on singletracks, and implement mathematical modeling of these forces, for a range of climatic conditions and geographic settings. Specifically, we focus on the hydrological and geomorphic impacts of singletracking, and highlight the importance of applying geomorphic principles in their design. Also, we demonstrate specific measures for establishing singletracks on hillslopes and in ephemeral stream channels. We discuss how climate, topography, surface roughness, hydrological connectivity, and pedology determine the processes of water runoff and soil erosion on singletrack trails. Further, we demonstrate how riders’ behavior determines the rate of shearing, wearing, compaction, deformation, and rutting of the singletrack, as well as the expansion of physical damages to the track’s surroundings. These conditions and effects determine the durability of singletracks, with implications for maintenance requirements over time. The specific implications of the emerging sector of electric mountain bikes on singletrack durability are discussed. Insights of this paper will benefit landscape designers and land managers aiming to foster ecotourism and sustainable recreation opportunities.

Human-Mediated Dispersal and the Rewiring of Spatial Networks

Humans fundamentally affect dispersal, directly by transporting individuals and indirectly by altering landscapes and natural vectors. This human-mediated dispersal (HMD) modifies long-distance dispersal, changes dispersal paths, and overall benefits certain species or genotypes while disadvantaging others. HMD is leading to radical changes in the structure and functioning of spatial networks, which are likely to intensify as human activities increase in scope and extent. Here, we provide an overview to guide research into HMD and the resulting rewiring of spatial networks, making predictions about the ecological and evolutionary consequences and how these vary according to spatial scale and the traits of species. Future research should consider HMD holistically, assessing the range of direct and indirect processes to understand the complex impacts on eco-evolutionary dynamics.

Weed hygiene practices in rural industries and public land management: Variable knowledge, patchy implementation, inconsistent coordination

Weed management science and practice largely focuses on eradicating, containing and reducing existing weed populations; the focus is on plants in situ. More recently, the redefinition of biosecurity to include weeds has seen greater attention paid to preventing the introduction of weeds to previously uninfested areas within countries. Thus weed hygiene has come to the fore, with a growing number of publications recommending a diverse range of practices to minimise the spread of weeds across farm, regional and state boundaries. Yet little is known about the uptake of weed hygiene practices. The aim of this paper is to evaluate the extent to which best practice weed hygiene is being implemented on, across and along private and public lands. Telephone interviews were conducted with 54 private and public land managers, weed contractors, and agricultural transport operators in New South Wales, Australia. Vehicle hygiene was commonly undertaken across all stakeholder groups when it was consistent with other goals, requirements or norms. Other practices, such as sequencing harvesting from least to most weedy paddocks or including weed hygiene clauses in contracts were often known, but rarely practiced because of the onerous labour and financial costs or concerns about social etiquette. Individual commitment to weed hygiene efforts were also undermined by intra and inter-organisational coordination challenges. Public debate and assessment are needed on the benefits and costs to society of weed hygiene compared to in situ weed control to determine where best to invest limited time and resources.