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Road verges represent new habitats providing an opportunity for enhancing biodiversity in human-altered landscapes. However, it is common practice to plant trees or sow species-poor seed mixtures regardless of their geographical o...
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Road verges represent new habitats providing an opportunity for enhancing biodiversity in human-altered landscapes. However, it is common practice to plant trees or sow species-poor seed mixtures regardless of their geographical origin. We assessed the effectiveness of spontaneous restoration to fulfil the requirements for both functions, the formation of vegetation cover to prevent erosion and native species-rich vegetation, which may provide conservation benefits. We sampled 113 vegetation plots on road verges in the Czech Republic, central Europe. The sampling plots were 25 m(2) in size and differed in age (1-42 years). We recorded surrounding landscape (land-cover categories, landscape heterogeneity, and length of roads and railways in a 1-km radius zone) and site factors (altitude, substrate texture, slope, aspect, and potential solar radiation) and analysed the data using multivariate methods. Species composition was significantly explained by successional age, altitude, substrate texture, and surrounding forest area. The total herb cover reached on average 30% already in the first 2 years, and later shrub and tree layers developed. Out of 320 identified vascular plant species, almost 5% (15 species) were endangered and 6% (19 species) were invasive aliens. Early successional stages were characterised by a high cover of insect-pollinated species, which can serve as important food sources for insects. Despite some limitations (poor seed sources and inconvenient site conditions), our results showed that spontaneous succession could be used more often in the restoration of road verges because this approach may provide an alternative, cost-effective solution of reasonable conservation value.
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Myrmecochory (the dispersal of seeds by ants) is a significant ecological process in sclerophyll woodlands, but habitat disturbance is known to alter the extent and success of this mutualism. We investigated the influence of soil ...
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Myrmecochory (the dispersal of seeds by ants) is a significant ecological process in sclerophyll woodlands, but habitat disturbance is known to alter the extent and success of this mutualism. We investigated the influence of soil disturbance on the composition of the seed-dispersing ant community. Surveys were conducted in roadside verges where soils are regularly disturbed by road maintenance activities. Using a 'cafeteria' bait station approach, we selected 24 roads of different widths to investigate ant composition and abundance in relation to soil disturbance. We found ant species richness was greater in non-disturbed than disturbed zones, where road verge width significantly influenced results. The composition and abundance of individual seed-dispersing ant species varied between disturbed and non-disturbed zones. Rhytidoponera metallica were more abundant in non-disturbed sites, whereas Melophorus bruneus and Monomorium rothseini were more frequently recorded in disturbed areas. Commonly found Iridomyrmex purpureus was significantly more abundant in disturbed zones in narrow roadsides and vice versa in wide roadsides, and strongly influenced total community composition. Variation in the abundance of commonly recorded Iridomyrmex and Monomorium genera were related more to site conditions (roadside width and habitat) than soil disturbance. The rich composition of seed dispersing ants in roadside environments, and the effects of soil disturbances on these ant communities that we describe, provide a key insight to important seed dispersal vectors occurring in fragmented rural landscapes.
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Linear structures include fences, roads, railways, canalised water ways and power lines, all man-made. Fencing as a way of managing livestock began in the late 1800s, and by the early twentieth century was almost fully implemented...
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Linear structures include fences, roads, railways, canalised water ways and power lines, all man-made. Fencing as a way of managing livestock began in the late 1800s, and by the early twentieth century was almost fully implemented throughout the Karoo sensu lato. The advent of these fences, and now in many instances, 'game proof' (similar to 2 m high) and electric fences have impacted native flora and fauna in various ways. Roads influence the quality and quantity of vegetation along corridors throughout the Karoo, with impacts on wildlife through increased mortality, but also provide foraging opportunities. Road-side structures, such as transmission poles, offer nest sites and perches in otherwise treeless landscapes, benefiting certain avifauna. Railway lines create similar corridors, carrying ungrazed vegetation along them. Their associated structures - culverts and (historically) steel frame bridges - provide nest sites for birds and some mammals. Transmission cables and pylons along power lines have mixed benefits to conservation, providing bird nest and perch sites, but can also cause bird mortalities. Unquestionably, these linear structures have had marked effects on the biota of the Karoo, through their effects on wildlife and livestock movement and mortality, plant demography and the spread of native and alien species.
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The main objective of this paper is to report the effect of shrub removal, mowing, and grazing as grassland management methods on spider diversity. Sampling was conducted in the Mátra Mountains and four disturbed main road verges...
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The main objective of this paper is to report the effect of shrub removal, mowing, and grazing as grassland management methods on spider diversity. Sampling was conducted in the Mátra Mountains and four disturbed main road verges in Hungary. Shrub removal and mowing positively affected diversity. Moderate grazing caused increasing diversity, but intensive grazing reduced spider diversity. The intensity of mowing maintenance had various effects on diversity depending on the landscape impact. It is worth reducing the intensity of the application of mosaic treatments and considering the long-term maintenance of edge habitats in these areas.
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Recent studies have focused on ways to enhance floral availability on arable farmland, but little attention has been paid to the importance of off-farm habitats in providing forage for pollinators within farmed landscapes. We cond...
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Recent studies have focused on ways to enhance floral availability on arable farmland, but little attention has been paid to the importance of off-farm habitats in providing forage for pollinators within farmed landscapes. We conducted a comparative study to assess bumblebees and flower abundance on farmed and off-farm habitats in two low-intensity systems in the UK, the Somerset Levels and the Outer Hebrides. In both farming systems, both on- and off-farm habitats contributed to the mosaic of bumblebee forage. In the Somerset Levels, track edges and road verges were particularly important sources of forage for long-tongued bumblebees. Cattle-grazed pasture in Somerset and winter-grazed pasture in the Outer Hebrides were also notable sources of bumblebee forage. Non-agricultural habitats need to be integrated into local land management plans to ensure the provision of forage for bumblebees throughout the breeding season.
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Roads may have an important negative effect on animal dispersal rate and mortality and thus the functioning of local populations. However, road verges may be surrogate habitats for invertebrates. This creates a conservation dilemm...
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Roads may have an important negative effect on animal dispersal rate and mortality and thus the functioning of local populations. However, road verges may be surrogate habitats for invertebrates. This creates a conservation dilemma around the impact of roads on invertebrates. Further, the effect of roads on invertebrates is much less understood than that on vertebrates. We studied the effect of roads on butterflies by surveying abundance, species richness and composition, and mortality in ten grassland patches along high-traffic roads (～50–100 vehicles per hour) and ten reference grassland patches next to unpaved roads with very little traffic (<1 vehicle per day) in southern Poland. Five 200-m transects parallel to the road were established in every grassland patch: at a road verge, 25 m from the verge, in the patch interior, and 25 m from the boundary between the grassland and field and at the grassland-arable field boundary. Moreover, one 200-m transect located on a road was established to collect roadkilled butterflies. The butterfly species richness but not abundance was slightly higher in grassland patches adjacent to roads than in reference grassland patches. Butterfly species composition in grasslands adjacent to roads differed from that in the reference patches. Proximity of a road increased variability in butterfly abundances within grassland patches. Grassland patches bordering roads had higher butterfly abundance and variation in species composition in some parts of the grassland patch than in other parts. These effects were not found in reference grassland patches, where butterfly species and abundance were more homogenously distributed in a patch. Plant species composition did not explain butterfly species. However, variance partitioning revealed that the presence of a road explained the highest proportion of variation in butterfly species composition, followed by plant species richness and abundance in grassland patches. Road mortality was low, and the number of roadkilled butterflies was less than 5% of that of all live butterflies. Nevertheless, the number and species composition of roadkilled butterflies were well explained by the butterfly communities living in road verges but not by total butterfly community structure in grassland patches. This study is the first to show that butterfly assemblages are altered by roads. These results indicate that: (1) grassland patches located near roads are at least as good habitats for butterflies as reference grassland patches are, (2) roads create a gradient of local environmental conditions that increases variation in the abundance of certain species and perhaps increases total species richness in grassland patches located along roads, and (3) the impact of roads on butterflies is at least partially independent of the effect of plants on butterflies. Furthermore, (4) the direct impact of road mortality is probably spatially limited to butterflies living in close proximity to roads.
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Diffuse sediment pollution impairs water quality, exerts a key control on the transfer and fate of nutrients and contaminants and causes deleterious impacts on freshwater ecology. A variety of catchment sediment sources can contri...
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Diffuse sediment pollution impairs water quality, exerts a key control on the transfer and fate of nutrients and contaminants and causes deleterious impacts on freshwater ecology. A variety of catchment sediment sources can contribute to such problems. Sediment control strategies and effective targeting of mitigation options therefore require robust quantitative information on the key sources of the sediment problem at catchment scale. Recent observations by Catchment Sensitive Farming Officers (CSFO's) in England have highlighted road verges damaged and eroded by passing vehicles particularly large farm machinery, and livestock herd movement as visually important potential sources of local sediment problems. A study was therefore undertaken to assess the relative importance of damaged road verges as a suspended sediment source in three sub-catchments of the Hampshire Avon drainage basin, southern UK. Road verge sediment contributions were apportioned in conjunction with those from agricultural topsoils and channel banks/subsurface sources. Time-integrating isokinetic samplers were deployed to sample suspended sediment fluxes at the outlets of two control sub-catchments drained by the Rivers Chitterne and Till selected to characterize areas with a low road network density and limited visual evidence of verge damage, as well as the River Sem sub-catchment used to represent areas where road verge damage is more prevalent. The findings of a sediment source fingerprinting investigation based on a combination of intermittent sampling campaigns spanning the period 22/5/02-27/4/08 suggested that the respective overall mean relative sediment contributions from damaged road verges were 5 ± 3%, 4 ± 2% and 20 ± 2%. Relative inputs from damaged road verges for any specific sampling period in the River Sem sub-catchment were as high as 33 ± 2%. Reconstruction of historical sources in the same sub-catchment, based on the geochemical record stored in a floodplain depth profile, suggested that the significance of damaged road verges as a sediment source has increased over the past 15-20 years. The findings provide important information on damaged road verges as a primary source of suspended sediment and imply that catchment sediment control strategies and mitigation plans should consider such verges in addition to those agricultural and channel sources traditionally taken into account when attempting to reduce sediment pressures on aquatic resources.
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The structure of Cerrado vegetation (sensu stricto) along roadsides was compared with that of protected areas (reserves). The superior stratum of reserves had 2.7 times more individuals and 1.4 times more species than on roadsides...
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The structure of Cerrado vegetation (sensu stricto) along roadsides was compared with that of protected areas (reserves). The superior stratum of reserves had 2.7 times more individuals and 1.4 times more species than on roadsides, while in the intermediate stratum there were 1.7 times more individuals and 25 % more species in reserves. Additionally, roadsides had a lower prevalence of tree species with thin bark and from forest physiognomies. In the intermediate stratum of roadsides there was a lower proportion of forest species, and also fewer species dispersed by animals. These differences occur, possibly because the vegetation of their edges is cleared during the construction of the roads and part of the soil is taken as landfill. Later, they suffer from a higher fire frequency and high coverage of exotic grasses (80 % average). Moreover, it is likely that the absence of some dispersers on roadsides may affect the recruitment of young plants. Despite these differences, the roadsides are able to maintain at least 70 % of tree species and 72 % of shrub species found in reserves. These results show that roadside vegetation can contribute to the conservation of the flora of Cerrado. This is particularly important considering that over 60 % of the original area of this ecosystem has been destroyed and that less than 4 % is protected. With 32,012 km of roads in the Cerrado alone, the roadside vegetation may represent a cumulative area of 96,000 of hectares, an area larger than many of the Cerrado's national parks.
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Some small mammal species use road verges as a habitat for sheltering. As a result, their populations suffer mortality from roadkill in an unknown extent. We analysed the road mortality of small mammals and the population impact o...
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Some small mammal species use road verges as a habitat for sheltering. As a result, their populations suffer mortality from roadkill in an unknown extent. We analysed the road mortality of small mammals and the population impact of roadkill on wood mouse along 1 year on a 4-km motorway stretch. To account for potential bias in carcass sampling, we conducted walking surveys with the traffic interrupted and we performed three carcass persistence experiments to estimate total number of roadkills. The estimations were contrasted with previous studies and the population abundance on the road verges. The spatial pattern and the effects of seasonality and traffic volume on roadkill were analysed. We recorded 84 rodent carcasses with a mean carcass persistence of 6.65 days (SE = 0.41). The estimations of roadkill ranged between 190.2 and 238.3 individuals km(-1) year(-1), with a mean value close to a monthly 6 % mortality for the most common specie. Roadkill was more frequent during the hottest and driest months, and showed a unimodal relation with traffic peaking at 8100 vehicles day(-1). A spatial aggregation of roadkill was detected with 80-190 m clustering. Our results suggest that, although rodents suffer greater roadkill mortality than previously reported, it affects a small percentage of the wood mouse population in our study area. This source of mortality is unlikely to affect population viability in the short term. Our results show that roadkill surveys should be specifically designed for small mammals to have a more accurate analysis of the effects of roadkill on their populations.
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Myrmecochory is an important mutualistic interaction, where ants provide seed dispersal services for many plant species. We examined the influence of soil disturbances associated with roadworks activity on ant-seed interactions in...
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Myrmecochory is an important mutualistic interaction, where ants provide seed dispersal services for many plant species. We examined the influence of soil disturbances associated with roadworks activity on ant-seed interactions in roadside environments in south-eastern Australia. In the study landscape, minor rural road reserves often provide critical habitat for endangered species and woodland ecosystems. We conducted seed-depot experiments to quantify the extent of ant-seed removal, and identified the contribution of different ant species to seed removal and elaiosome consumption (cheating) interactions, in disturbed and non-disturbed roadside zones. Twenty-six ant species were recorded interacting with seeds; however, only a few species were responsible for dispersing most seeds. We found soil disturbance and roadside width influenced observed ant-seed interactions, which was largely explained by individual species habitat and behavioural traits.Iridomyrmex purpureusremoved a higher proportion of seeds in soil disturbed zones, whileRhytidoponera metallicacarried out more seed removals in narrow roadsides.R. metallicaandMelophorus bruneustypically carried out seed removals (only), whileMonomoriumandPheidole spp.almost exclusively carried out cheating behaviours. These results highlight the complex nature of ant-plant interactions is association with novel soil disturbance regimes, where ants perform a critical seed dispersal service for myrmecochorous roadside vegetation.
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