Roadside Management Research Articles

Roadside habitat: Boon or bane for pollinating insects?

Pollinators, which provide vital services to wild ecosystems and agricultural crops, are facing global declines and habitat loss. As undeveloped land becomes increasingly scarce, much focus has been directed recently to roadsides as potential target zones for providing floral resources to pollinators. Roadsides, however, are risky places for pollinators, with threats from vehicle collisions, toxic pollutants, mowing, herbicides, and more. Although these threats have been investigated, most studies have yet to quantify the costs and benefits of roadsides to pollinators and, therefore, do not address whether the costs outweigh the benefits for pollinator populations using roadside habitats. In this article, we address how, when, and under what conditions roadside habitats may benefit or harm pollinators, reviewing existing knowledge and recommending practical questions that managers and policymakers should consider when planning pollinator-focused roadside management.

Qualitative sustainability assessment of road verge management in France: An approach from causal diagrams to seize the importance of impact pathways

A road verge, also known as a roadside, is a strip of grass or vegetation, sometimes shrubs and trees, that forms a space on the public property located along a road or highway. They require regular maintenance, one of the most relevant reasons being the safety of road users, which implies for territory planners making decisions about the period of maintenance, frequency, the mowing height, or whether or not remove cut biomass from the roadside among others. As highlighted in previous studies, the maintenance strategy decided on has a range of positive and negative impacts on the ecosystem services provided by road verges. Today, however, there is a lack of a formal and holistic view of how these maintenance practices affect the ecosystem services (ES) provided by the roadside. In order to improve the sustainability management of these areas, this paper proposes to use the concept of causal diagrams from the systems theory and literature analysis. This concept helps to structure and represent the impact of road verge maintenance decisions on ES and their interrelationships through causal networks. Nine interrelated causal diagrams were then developed. These diagrams are the first attempt at a qualitative assessment of the impact of roadside management on ES. This work is the first step towards a formal holistic model to assess the sustainability impacts of road verges and the development of decision-making tools.

Effects of roads on small-mammal movements: Opportunities and risks of vegetation management on roadsides

Roads can block animal movement and reduce persistence of species living in road surroundings. Movement restrictions on local populations may even increase extinction risk of abundant small mammals. However, road verges (road managed area between the edge of the road and the beginning of private land) may provide refuge and corridors for small mammals when properly managed. Information on the effects of roads and roadside management on small-mammal movement is still scarce for low traffic roads (<20,000 vehicles per day) crossing well-preserved habitats. We aimed to fill this gap by comparing fine-scale movement patterns of wood mice (Apodemus sylvaticus) in a road and in a similar roadless area without management. Both areas consisted of a well-preserved Mediterranean agro-silvo pastoral system. We studied several movement patterns: road crossings, verge use, length, and direction of movement. Additionally, we assessed how roadside management, animals’ sex and residency status, season and microhabitat affect movement at the road area. At the roadless area, we defined a virtual road and verges at equivalent locations to the road area for comparison purposes. We gathered capture-mark-recapture data for two years to characterize movement patterns. Wood mice tended to avoid the road by crossing it less often and moving away from it more frequently than from equivalent locations in the roadless area. Wood mice used road verges more frequently than virtual verges and moved more often parallel to the road than to the virtual road. Road crossings were more frequent after firebreak openings (strips of mowed land) in surrounding areas and near taller shrubs. Also, males used road verges more often than females. Differences on several movement patterns between areas and their trends within the road area can be explained mainly by the presence of the road and roadside vegetation management (e.g., firebreaks openings). We suggest roadside vegetation management practices (e.g., avoid land mowing; maintain vegetation strips) to promote the role of verges as refuges and/or corridors for small mammals.

EFFECTS OF MOWING AND PRESCRIBED FIRE ON AN INVASIVE POPULATION OF SCABIOSA ATROPURPUREA (DIPSACACEAE) IN NORTH-CENTRAL TEXAS

Scabiosa atropurpurea is an invasive herbaceous plant now found in 9 states, including 19 counties in north-central Texas and 2 counties in adjacent Oklahoma. Scabiosa atropurpurea forms dense colonies along roadsides and in old agricultural fields and poses a threat to native and improved grasslands. We evaluated the response of S. atropurpurea to mowing and prescribed fire. Mowing caused a marked increase in the density of S. atropurpurea. However, S. atropurpurea declined when there was no management at all and when exposed to growing season fire. Mowing of S. atropurpurea during roadside management and other management contexts leads to persistence and spread of this species. In complex communities, this plant will likely decline and growing season fires may help accelerate these declines.

Roles of roadside vegetation in insect conservation in Australia

AbstractThe extent and variety of roadside environments in Australia in largely anthropogenic landscapes render them substantial remnant habitats for insect biodiversity. The importance of these areas for insect biodiversity conservation and the key threats they face are discussed, as well as the needs for their protection and conservation management. Many rural roadsides harbour significant patches of native vegetation, including rare and threatened flora now scarce elsewhere. Other values of roadside vegetation include habitat remnants, seasonal refuges, corridors and shelters for insect movements and population connectivity. Examples are given of the importance of roadsides for individual threatened insect species. Roadside environments are under substantial threat from clearing, development and unintentional degradation through a variety of activities. The diverse responsibilities of roadside management, increasingly to harmonise human safety and amenity needs with biodiversity conservation, can readily incorporate considerations of insect diversity and occurrence of notable individual species. The conservation of remnant vegetation and ecological restoration of roadside corridors are highlighted as paramount for maintaining biodiversity and connectivity under increased human activity and environmental extremes.

Road network forms specific stations for living organisms in the conditions of the steppe zone

The state of art analysis of available published data allowed to determine the features of the roadside ecosystems formation and the possibility of further development of biodiversity conservation measures. In Ukraine and around the world, road infrastructure is an important economic and social object that has a negative impact on the environment. This takes place due to environmental pollution, fragmentation of habitats, biodiversity loss, etc. At the same time, on the roadsides the stations (microhabitats) are being formed. They can be a barrier to motor vehicle pollution and provide available shelters for living organisms. Road operation usually affects the structure of roadside vegetation. There is an increase in the number of of annual plant species and a decrease in perennials. Favourable conditions are also created for the spread of heliophytes and xerophytes. Roads are a source of chemical pollution that affects all components of roadside ecosystems. The amount of pollutants is mainly dependent on the traffic intensity and road width. The creation of roadside forest plantations significantly reduces the negative impact of vehicles. Wood plantations contribute to better carbon deposition, which is an integral part of many vehicle pollutants, and create a barrier for pollutants coming far from roads. Forest belt can also be a refuge for many species of animals and combine fragmented habitats around. Because plants and small animals at roadside stations are bound to their localities, they are able to accumulate much amount of ecotoxicants, especially heavy metals, which should be taken into account when conducting local business. For the living of animals in roadside stations, the characteristics of specific confined plant community, microclimate and landform are quite important. Due to the linearity and long distances, roadsides provide migration ways for many species. The developed roadside habitats may be the refugia for not only common, but for rare animals. We should conclude that further research of the environmental benefits of roadside ecosystems in the Steppe zone of Ukraine would allow developing effective measures for roadside management in the frames of nature conservation.

Rapid Assessment of Roadsides as Potential Habitat for Monarchs and Other Pollinators

Sustaining native pollinator populations and reversing declines in species such as the monarch butterfly (Danaus plexippus) will require enhancing and maintaining habitats across many regions and land use sectors. Rights-of-way, such as the areas surrounding roads, have long been regarded as important habitat for pollinators due to their ubiquitous nature and management for herbaceous species including nectar plants and larval host plants. With better information regarding the quality of pollinator habitat in roadside rights-of-way, managers can identify the location of potential habitat and evaluate the effects of management activities. We conducted a survey of roadside managers to determine needs and limitations related to assessing and managing rights-of-way as monarch habitat. Survey results indicated that managers are often limited by time, funding, and expertise in plant identification. Based on survey results and consultations with roadside managers, we developed a protocol for rapid assessment of roadside rights-of-way (hereafter, Rapid Assessment) that can be easily implemented by managers and is flexible based on the expertise of the observer and the data needs of the roadside management authority. Using readily available software, the field data are automatically processed through a Roadside Monarch Habitat Evaluator to generate habitat quality scores that may be used by managers to describe the habitat resources and to inform management strategies. We field-tested the protocol at roadsides in Minnesota and compared results with a more intensive protocol for monarch habitat monitoring (the Integrated Monarch Monitoring Program). We found that the Rapid Assessment provided similar data as the more intensive protocol regarding milkweed densities, nectar plant species richness, and monarch use of sites (eggs and larvae, when detection levels were sufficient). Observed high habitat values in roadside rights-of-way confirm the potential of such habitat for pollinator and monarch conservation.

Establishing sustainable roadside vegetation communities of high botanical and aesthetic value: the basic concept statement and experimental justification

The basic principles for the development of a new greening system for the region of Belarus aimed at creation and restoration of sustainable roadside plant communities of high botanical and aesthetic value are formulated on the basis of the use of conservation, restoration and “incorporation” methods of flowering native plant species, characteristic of a particular region. The statements of the concept are developed and recommended for roadways and highways in the Republic of Belarus and tested on the model site between the city of Myadel and the resort village of Naroch of Highway P28. Roadside vegetation management practices in other countries as well as our research has shown that along the investigated roads there is a high adaptive potential of native flora; by changing the mowing regime, sustainable plant communities can be established while enhancing the aesthetics and expressiveness of key elements of the landscape of the roadsides. The implementation of the strategy for each geobotanical region depends on the development of an assortment of native plant species that can be used for the greening of roadside areas. This should be done by taking into account their geobotanical and edaphic features, creation of a seed bank for grass mixtures, the formation of natural genetic reserves (field banks) of meadow flora to conserve the local and overall ecosystem and genetic balance. For examples, the atlas of plants “Roadside flowers” developed for the National Park “Narochansky” is recommended for use in roadsides (verges) greening within the boundaries of the Oshmyany– Minsk geobotanical district. To expand the use of gained positive experience on increasing the biodiversity of roadside ecosystems and reducing the cost of their maintenance, it is desirable to implement this strategy for the entire road network of Belarus, which will require adjustment in technologies for managing roadside ecosystems, based on priorities of conservation, restoration and formation of native plant communities, including meadows and wetlands.

Roads support the spread of invasive Asclepias syriaca in Austria

Summary Asclepias syriaca is an invasive alien plant that has recently spread in Central Europe. The spatiotemporal spread of A. syriaca was reconstructed based on the distribution data for Austria. A. syriaca has increased in abundance and range, especially after the year 2005. At present, the species occurs primarily in eastern Austria (Vienna, Lower Austria), while it was rarely recorded in southern and western Austria. Further spread and range filling is probable. Moreover, the distribution of A. syriaca along roadsides and the role of road type and adjoining land use in facilitating its spread were studied in an area of high presence of the species in Lower Austria in 2018. It was shown that A. syriaca occurred regularly along roadsides and the chance of finding A. syriaca was higher along unpaved roads and along roadsides bordered by forests and grassland. The results indicate that the road network contributes to the spread of A. syriaca in the study area, most likely by providing suitable and well connected habitats. If A. syriaca densities are to be lowered, emphasis should be placed on both a proper roadside management (e.g., mowing regimes) and on the control of the species in the respective adjacent habitat.

How are biodiversity and dispersal of species affected by the management of roadsides? A systematic map

BackgroundIn many parts of the world, roadsides are regularly managed for traffic-safety reasons. Hence, there are similarities between roadsides and certain other managed habitats, such as wooded pastures and mown or grazed grasslands. These habitats have declined rapidly in Europe during the last century. For many species historically associated with them, roadsides may function as new primary habitats or as dispersal corridors in fragmented landscapes. Current recommendations for roadside management to promote conservation values are largely based on studies of plants in semi-natural grasslands, although such areas often differ from roadsides in terms of environmental conditions and disturbance regimes. Moreover, roadsides provide habitat not only for plants but also for many insects. For these reasons, stakeholders in Sweden have emphasised the need for more targeted management recommendations, based on actual studies of roadside biodiversity.MethodsThis systematic map provides an overview of the available evidence on how biodiversity is affected by various forms of roadside management, and how such management influences the dispersal of species along roads or roadsides. We searched for literature using 13 online publication databases, 4 search engines, 36 specialist websites and 5 literature reviews. Search terms were developed in English, Danish, Dutch, French, German, Norwegian, Spanish and Swedish. Identified articles were screened for relevance using criteria set out in a protocol. No geographical restrictions were applied, and all species and groups of organisms were considered. Descriptions of included studies are available in an Excel file, and also in an interactive GIS application that can be accessed at an external website.ResultsOur searches identified more than 7000 articles. The 207 articles included after screening described 301 individual studies considered to be relevant. More than two-thirds of these studies were conducted in North America, with most of the rest performed in Europe. More than half of the studies were published in grey literature such as reports from agencies or consultants. The interventions most commonly studied were herbicide use, sowing and mowing, followed by soil amendments such as mulching and fertiliser additions. The outcomes most frequently reported were effects of interventions on the abundance or species richness of herbs/forbs, graminoids and woody plants. Effects on insects and birds were reported in 6 and 3% of the studies, respectively.ConclusionsThis systematic map is based on a comprehensive and systematic screening of all available literature on the effects of roadside management on biodiversity and dispersal of species. As such it should be of value to a range of actors, including managers and policymakers. The map provides a key to finding concrete guidance for conservation- and restoration-oriented roadside management from published research. However, the map also highlights important knowledge gaps: little data was found for some geographical regions, research is heavily biased taxonomically towards plants, and no study was found on how species dispersal was affected by roadside management. The map could therefore be a source of inspiration for new research.

How are biodiversity and dispersal of species affected by the management of roadsides? A systematic map protocol

Abstract Background In many parts of the world, roadsides are regularly managed for traffic-safety reasons. Hence, there are similarities between roadsides and certain other managed habitats, such as wooded pastures and mown or grazed grasslands. In contrast to roadsides, the latter habitats have declined rapidly in Europe during the last century, and today only a fraction of their former extent remains. For many species historically associated with these habitats, roadsides may therefore function as new primary habitats or as dispersal corridors in fragmented landscapes. Current recommendations for roadside management to promote conservation values are largely based on studies of plants in semi-natural grasslands, although such areas often differ from roadsides in terms of environmental factors and impacts. Moreover, roadsides provide habitats not only for plants but also for many insects, especially if they are sandy and exposed to the sun. For these reasons, stakeholders in Sweden have emphasised the need for more targeted management recommendations, based on actual studies of roadside biodiversity. Methods The proposed systematic map is intended to provide an overview of the available evidence on how biodiversity is affected by various forms of roadside management, and how such management influences the dispersal of species along roads or roadsides. Relevant interventions include e.g. mowing, shrub removal, control of invasive/nuisance species, sowing or planting, burning, grazing by livestock, scraping and ditching. Non-intervention or alternative forms of roadside management will be used as comparators. Relevant outcomes include measures of species or genetic diversity, the abundance of individual species or groups of organisms, species distribution patterns, and movement rates of individuals or propagules. Searches will be made for peer-reviewed and grey literature in English and several other languages. No geographical restrictions will be applied, and all species and species groups will be considered.

The influence of mowing regime on the soil seed bank of the invasive plant Ambrosia artemisiifolia L.

Ambrosia artemisiifolia is an invasive annual herb infamous for the high allergenicity of its pollen, which is related to increasing medical costs. Additionally, it can cause serious yield losses as agricultural weed. Common ragweed seeds accumulate in the soil and can remain therein viable for decades, which poses a problem for the sustainable management of these populations. A long term management should thus target a reduction of the soil seed bank. We observed the influence of four different mowing regimes on the ragweed soil seed bank at six roadside populations in eastern Austria. The mowing regimes were based on methods from common roadside management practice and specifically adapted to reduce seed produc tion. After three years of application, the soil seed bank was indeed reduced by 45 to 80 percent through three of the four mowing regimes tested. Therefore, we suggest that the best mowing regime for the most effective reduction of the size of the soil seed bank is the one consisting of one cut just after the beginning of female flowering (around the 3 rd week of August in Eastern Central Europe), followed by a second cut 2–3 weeks later.

Monarch–parasite interactions in managed and roadside prairies

Roadsides cover an extensive area within the United States, are actively managed, and have been considered potential areas of habitat for several taxa. For monarch butterflies (Danaus plexippus), roadsides may act as important habitat along their migration route by providing nectar and host plant resources, which is especially important considering the loss and fragmentation of monarch habitat throughout their breeding range. However, the interactions between monarchs and their parasites may be altered in these areas by management regimes. Monarchs are infected by Ophryocystis elektroscirrha (OE), an obligate, spore-forming protist of monarchs and queens, and Lespesia archippivora, a generalist tachinid fly parasitoid. Roadsides could increase parasitism by concentrating monarchs in certain areas or decrease parasitism by modifying habitat (e.g., the roadside management practice of mowing could reduce the availability of OE spores by removing the above ground portion of host plants and generating re-growth), including the distribution and abundance of host plants. In this study, we compared the proportion of infected monarchs between roadside prairies and managed prairies to evaluate the potential of roadside prairies as habitat for monarch butterflies. Our results suggest that the proportion of infected monarchs does not differ between roadside prairies and managed prairies. Thus, roadsides may provide habitat for monarchs that is similar in quality (at least in terms of parasitism rates) to managed prairies. The role of roadsides as habitat for monarchs should be considered when developing roadside management strategies.

Influence of ecology and landscape on snake road mortality in a sagebrush‐steppe ecosystem

AbstractRoads fragment our landscape, posing a severe threat to the persistence of wildlife populations through losses of individuals to direct mortality and decreased connectivity. Although they possess a particular suite of life history characteristics that make them especially vulnerable, snakes tend to be underrepresented in research examining vertebrate road mortality. Here, we report a statistical analysis of snake mortality along a 183‐km road circuit in sagebrush‐steppe habitat located in southeastern Idaho. We describe differential road mortality across snake species, season, sex and age. We also analyze both fine‐scale and broad‐scale habitat measurements to identify various habitat and landscape factors associated with snake road mortality. Our results show clearly that snake road mortality is influenced by interactions among demographic, ecological and temporal factors. Vagile species and life stages were particularly vulnerable to road mortality during periods of peak activity. Gophersnakes dominated our road observations, with adult male mortality peaking in spring and high casualties of neonates in the fall. Snake crossings were especially common along roadsides with high vegetative cover, in areas dominated by non‐native grasses. These results suggest the potential for snake populations to become fragmented over time, and that habitat conversion and species invasions may be compounding this effect. This study suggests that conservation efforts need to account for inter‐ and intraspecific differences in road mortality risk and provides guidance for roadside management that may serve to minimize vertebrate mortality on roads.

A review of pollinator conservation and management on infrastructure supporting rights-of-way

Early successional landscapes along or adjacent to infrastructure installations have been highlighted as potential pollinator conservation zones that provide environmental benefits and ameliorate some of the negative impacts of wildland conversion. Habitat development and management initiatives in this field are active, but vetted support for particular techniques and strategies is lacking and technical information is diffuse. We reviewed the current scientific and technical literature relating to right-of-way and roadside management to produce an overview. Surveys and comparative studies dominate the literature, with limited manipulative experimentation and limited tests of best management practices. Local floristic diversity is shown to be a determinant of butterfly, bee, and fly patterns but data is almost entirely lacking on vertebrate pollinators. The degree to which these linear landscape corridors can promote movement and connectivity is also not well addressed, yet there is a focus in the conservation community to promote migrations and movement. Contrasting results are reported for the impact of disturbance regimes associated with management (mowing and herbicide use), and there is also only minimal attention given to the potential negative impacts that are experienced by pollinators on rights-of-way. Even with the limited literary accounts of pollinator management in these landscapes we believe infrastructure landscapes can provide substantial benefits to pollinator species and ecosystem services and encourage further management-based investigations. Please find supplementary files to this article in the menu on the left side.

Classification of Roadside Weeds along Two Highways in Different Climatic Zones According to Ecomorphological Traits

Growth of vegetation in curbside cracks causes deterioration of asphalt and curbs, reducing road longevity and safety capabilities. Road managers spend a considerable amount of time and money on roadside vegetation management every year. The vegetation in curbside cracks in these study regions is managed approximately once a year by mowing and road sweeping using street-sweeper trucks. Nevertheless, ideal management practices of roadside vegetation have not yet been established partly due to insufficient knowledge of the ecological strategies of plants invading roadsides, especially curbside cracks. Although establishment of plants in the cracks might be restricted due to severe anthropogenic road disturbances, the cracks could be habitats for species with specific ecological traits. The objective of this study was to clarify the floristic and functional characteristics of roadside weeds, particularly species invading curbside cracks, to provide information for effective road management. The species composition of plants invading the cracks was surveyed along Route 3 (southern Japan) and Route 4 (eastern Japan) in different climatic zones, based on 108 floristic inventories. We compared species occurrence and composition to characterize the dominant ecomorphological traits of the species. In total, 163 species occurred in curbside cracks along both routes. Species composition of vegetation in curbside cracks was more variable between the routes than between land-use types. Of the 54 species, more than 5% occurred in all plots, and only three had differences in occurrence among land-use types. Ecomorphological trait composition patterns of the species were similar across land-use types. From these results, we found that regardless of differences in species composition among regions, climatic conditions, and surrounding land-use type, there were some dominant ecomorphological traits of roadside vegetation with plants in curbside cracks, such as ephemeral monophytes that are barochorous or anemochorous. By contrast, rhizomatous perennials, which cause greater deterioration of asphalt than ephemeral monophytes, were rare along the cracks. Although vegetation composition and structure generally depend on land-use types and disturbance regimes, linear landscape elements such as curbsides might be habitats for plants adapted to road disturbances. Roadside vegetation management, such as mowing and road sweeping once a year, seems sufficient to restrict establishment of rhizomatous perennials around Japan.

Integrating farming techniques in an ecological matrix model: Implementation on the primrose ( Primula vulgaris)

Several studies have proven the importance of field margins in sustaining biodiversity and other work has been done on the effect of field management on field margin flora. However few models have been built to predict the effects of field management on the flora. Our project addresses this need for a model capable of predicting the effect of cropping techniques and their timing on the flora of field margins. Primula vulgaris is a biodiversity indicator, characteristic of undisturbed flora and found in field margins and woodlands: its population has been declining for several years. We created a temporal matrix model of P. vulgaris populations on field margins, taking into account the effects of field, field margin and roadside management based on literature and expert knowledge. We then analysed its sensitivity to demographic parameters by comparing lambda (growth rate) sensitivity and elasticity. We compared the management parameter effect using the relative growth rate of the population after 6 years of simulation. Sensitivity analysis to biological parameters showed the importance of adult survival and seed production and germination. Results show that P. vulgaris is particularly sensitive to broad-spectrum herbicides and that other management techniques like early mowing, scything and scrub-killer (diluted broad-spectrum herbicide or specific herbicide) are less aggressive. Our simulations show that management of cash crops in Brittany is too aggressive for P. vulgaris populations and that 4–5 years of grassland in the adjacent field are necessary to maintain populations.

Temporal, Spatial, and Landscape Habitat Characteristics of Moose–Vehicle Collisions in Western Maine

We analyzed moose (Alces alces)–vehicle collisions (MVCs) in western Maine, USA, from 1992 to 2005 (n = 8,156) using Geographic Information Systems to identify patterns of temporal and spatial distribution and develop predictive models based on road and landscape characteristics. We used chi-square and correlation analyses to assess temporal characteristics of MVCs, K-function and kernel analyses to identify spatial clusters of MVCs, and logistic regression to relate covariates for traffic, land-cover, land-form, and relative moose abundance to probability of MVC. We evaluated candidate models using Akaike's Information Criterion, area under the receiver operating characteristic curve (AUC), and the percentage of correctly classified observations. Most (81.6%) MVCs occurred from May to October, with peak monthly frequencies in June (18.6%). Moose–vehicle collisions were clustered spatially on roads at local (0–4 km) and regional scales (22–41 km and 45–54 km), but not at intermediate scales. Traffic-related covariates predicting MVCs included traffic volume and speed limit. For each additional 500 vehicles/day, odds of a location being an MVC increased by 57%. For each 8-km/hr increase in speed limit, odds of an MVC increased by 35%. Landscape composition covariates best predicted MVCs within a 2.5-km radius of the collision site. Mean percent cover within 2.5 km of MVCs was comprised of 36% more cutover forest, 10% more coniferous forest, 5% less deciduous–mixed forest, and 10% less nonwoody wetland than for random points. For every 5% increase in percent cutover and coniferous forest within 2.5 km of the road, predicted odds of MVC increased by 36% and 19%, respectively. Landscape configuration covariates best predicted MVCs within the 5.0-km radius. Moose–vehicle collisions were associated with areas of less interspersion of cover types; for each 5% increase in an index of interspersion–juxtaposition, predicted odds of MVC decreased by 11%. Our final model attained high predictive power (AUC = 0.835) and validation accuracy (75.0%). The model also proved robust to physiographic variation, exhibiting high predictive power (AUC = 0.828) and validation accuracy (68.8%). Managers seeking to prioritize resources for reducing MVCs or predicting future areas of high MVC probability should assess land-cover composition and configuration surrounding MVC hotspots at geographic extents out to 2.5–5 km and use this information to plan expensive roadside management practices such as fencing. The importance of traffic and landscape covariates in our modeling suggests that effective management to reduce MVCs will require a complex combination of driving speed reductions and modifications to forest management along roads.

Temporal, Spatial, and Landscape Habitat Characteristics of Moose—Vehicle Collisions in Western Maine

Abstract:We analyzed moose (Alces alces)‐vehicle collisions (MVCs) in western Maine, USA, from 1992 to 2005 (n= 8,156) using Geographic Information Systems to identify patterns of temporal and spatial distribution and develop predictive models based on road and landscape characteristics. We used chi‐square and correlation analyses to assess temporal characteristics of MVCs,K‐function and kernel analyses to identify spatial clusters of MVCs, and logistic regression to relate covariates for traffic, land‐cover, land‐form, and relative moose abundance to probability of MVC. We evaluated candidate models using Akaike's Information Criterion, area under the receiver operating characteristic curve (AUC), and the percentage of correctly classified observations. Most (81.6%) MVCs occurred from May to October, with peak monthly frequencies in June (18.6%). Moose‐vehicle collisions were clustered spatially on roads at local (0–4 km) and regional scales (22–41 km and 45–54 km), but not at intermediate scales. Traffic‐related covariates predicting MVCs included traffic volume and speed limit. For each additional 500 vehicles/day, odds of a location being an MVC increased by 57%. For each 8‐km/hr increase in speed limit, odds of an MVC increased by 35%. Landscape composition covariates best predicted MVCs within a 2.5‐km radius of the collision site. Mean percent cover within 2.5 km of MVCs was comprised of 36% more cutover forest, 10% more coniferous forest, 5% less deciduous‐mixed forest, and 10% less nonwoody wetland than for random points. For every 5% increase in percent cutover and coniferous forest within 2.5 km of the road, predicted odds of MVC increased by 36% and 19%, respectively. Landscape configuration covariates best predicted MVCs within the 5.0‐km radius. Moose‐vehicle collisions were associated with areas of less interspersion of cover types; for each 5% increase in an index of interspersion‐juxtaposition, predicted odds of MVC decreased by 11%. Our final model attained high predictive power (AUC = 0.835) and validation accuracy (75.0%). The model also proved robust to physiographic variation, exhibiting high predictive power (AUC = 0.828) and validation accuracy (68.8%). Managers seeking to prioritize resources for reducing MVCs or predicting future areas of high MVC probability should assess land‐cover composition and configuration surrounding MVC hotspots at geographic extents out to 2.5–5 km and use this information to plan expensive roadside management practices such as fencing. The importance of traffic and landscape covariates in our modeling suggests that effective management to reduce MVCs will require a complex combination of driving speed reductions and modifications to forest management along roads.

Strip Malls, City Trees, and Community Values

Strip malls (also known as mini-malls) are a common urban land use, historically promoted by U.S. zoning practices that concentrate retail and commercial development in a narrow band along arterials and major streets. More recently, communities are redeveloping mini-mall zones, expanding landscape plantings as biotechnology, and attempting to create a sense of place. This study assessed public response to urban forest and landscape options. Surveys depicted varied roadside, property-edge treatments. Residents of three major cities in the Pacific Northwest, U.S., were asked to indicate their preferences and perceptions concerning a four-concept framework: visual quality, retail perceptions, patronage behavior, and pricing for goods and services. Respondents preferred landscaped roadsides and report positive retail behavior such as willingness-to-pay 8.8% more for goods and services in well-landscaped malls. Roadside management guidelines are proposed based on the research results.