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Railway Ecology
Abstract
This book is open access under a CC BY 4.0 license.
This book provides a unique overview of the impacts of railways on biodiversity, integrating the existing knowledge on the ecological effects of railways on wildlife, identifying major knowledge gaps and research directions and presenting the emerging field of railway ecology.
The book is divided into two major parts: Part one offers a general review of the major conceptual and theoretical principles of railway ecology. The chapters consider the impacts of railways on wildlife populations and concentrate on four major topics: mortality, barrier effects, species invasions and disturbances (ranging from noise to chemical pollution). Part two focuses on a number of case studies from Europe, Asia and North America written by an international group of experts.
Chapters (19)
Railways play a major role in the global transportation system. Furthermore, railways are presently being promoted by several governments thanks to their economic and environmental advantages relative to other means of transportation. Although railways have clear advantages, they are not free of environmental problems. The objective of this book is to review, assess, and provide solutions to the impacts of railways on wildlife. We have divided the impacts of railways on biodiversity into four main topics: mortality, barrier effects, species invasions, and environmental disturbances, with the latter ranging from noise to chemical pollution. Railways share several characteristics with roads and with power lines when the trains are electric. Therefore, much can be learned from studies on the impacts of roads and power lines, taking into account, however, that in railways, the two are often combined. Besides the similarities with roads and power lines, railways have specific characteristics. For instance, railways have lower traffic intensity but trains usually have much higher speeds than road vehicles, and the electric structures in railways are typically lower than in most power lines. Thus, railways pose specific challenges and require specific mitigation measures, justifying calling the study of its impacts on biodiversity “railway ecology.”
Wildlife mortality on roads has received considerable attention in the past years, allowing the collection of abundant data for a wide range of taxonomic groups. On the contrary, studies of wildlife mortality on railway tracks are scarce and have focused primarily on a few large mammals, such as moose and bears. Nevertheless, many species are found as victims of collisions with trains, although certain taxonomic groups, such as amphibians and reptiles, and/or small bodied species are reported infrequently and their mortality is probably underestimated. However, no assessment of population impacts is known for railways.
Recording wildlife mortality on railways is challenging as they have narrow corridors and lower accessibility. To improve mitigation measures, surveys must be systematic and their frequency depending on the targeted species traits and biology. To obtain unbiased estimates in diverse contexts, the data should be corrected using mortality estimators. Mitigation measures must avoid that animals remain on the tracks, as trains cannot be instantly stopped. Box culverts, amphibian tunnels, and under- or overpasses allow a safe crossing, whereas exclusion fences, olfactory repellents, sound signals and sound barriers prevent the crossing of railways. Habitat management in railway verges improves the animal capability to evade trains.
In this chapter we provide practical suggestions, together with examples, to identify, monitor and mitigate railway barrier effects on wildlife, as this is considered one of the railways’ greatest impacts. Railways can be both physical and behavioral barriers to wildlife movement, as well as disturbance to populations living close to them. Also, mortality is recognized as an important contribution to the barrier effect. However, the consequences of habitat loss, and fragmentation due to railways alone remain largely unexplored. Barrier effects have mainly been mitigated with wildlife passes, with the effectiveness of this tool being one of the most-studied topics in Railway Ecology. Methods formerly employed to monitor pass usage, such as track beds or video-surveillance, are now being replaced by molecular ones. Among the latter methods, genetic fingerprinting allows individual-based approaches, opening the door to population-scale studies. In fact, genetic sampling allows for the assessment of functional connectivity, which is closely linked to successful reproduction and population viability, variables not necessarily coupled with crossing rates. There is strong evidence that railway verges offer new habitats for generalist species and for opportunistic individuals, a point that deserves to be experimentally explored in order to find wildlife-friendly policies. Preventing animals from crossing (e.g., by fencing), should be reserved for collision hotspots, as it increases barrier effects. Instead, it has been shown that warning signals or pole barriers effectively reduce collisions without increasing barrier effects. In this respect, we argue that computer simulations are a promising field to investigate potential impact scenarios. Finally, we present a protocol to guide planners and managers when assessing barrier effects, with emphasis on monitoring and mitigation strategies.
Biological invasions are a major component of global environmental change, threatening biodiversity and human well-being. These invasions have their origin in the human-mediated transportation of species beyond natural distribution ranges, a process that has increased by orders of magnitude in recent decades as a result of accelerating rates of international trade, travel, and transport. In this chapter, we address the role that overland transportation corridors, particularly railways, have in the transport of non-native species. We focus specifically on the role of rail vehicles in dispersing stowaway species, i.e. species that are moved inadvertently and that are not specific to the commodities being transported; we also focus on the natural dispersal and establishment of non-native species along railway edges. We place these processes in the context of biological invasions as a global phenomenon and provide examples from the literature. We also list general management recommendations for biological invasions highlighting the particularities associated with their management in railway transport systems. Following previous studies, we briefly outline four possible management approaches: (1) “Do nothing;” (2) “Manage propagule supply;” (3) “Manage railway environments;” and (4) “Act over the invasive populations directly”. These approaches are not mutually exclusive, and they range from an expectation that natural processes (e.g. ecological succession) will drive the invaders out of the ecosystems, to the application of measures to extirpate the invaders directly (e.g. manual removal). We highlight that best practices for the management of invaders in railway-related systems may be difficult to generalize and that they may have to be considered on a case-by-case basis. We end by stressing that research on railways in the context of biological invasions remains scarce, and that fundamental knowledge for understanding the relative importance of this transport system in the dispersal of species and on how this process should be dealt with remains largely lacking.
In this chapter, we review the level of disturbance caused by railways due to noise and vibration, air, soil and water pollution, and soil erosion. There is evidence that soil and hydrology contamination may affect vegetation and aquatic fauna while noise can affect terrestrial vertebrates. In fact, noise, light, and vibration due to railways have been observed to reduce the abundance and richness of some insects, amphibians, and birds, and to cause avoidance behaviour on predators. Interestingly, reptiles, some bird species, small mammals, and large mammals seem to ignore rail traffic and benefit from the vegetation planted in the railway verges that provide food and shelter. Some engineering structures have been implemented to reduce the effects of railway disturbance: rail fastenings, rail dampers, under-sleeper pads, and noise barriers are applied to minimize noise and vibration; washing with water and cleaning the ballast are used to mitigate soil pollution; and grass plantation, the use of gypsum and application of compost/mulch coverage, are applied to control soil erosion.
Many studies have evaluated bird mortality in relation to roads and other human structures, but little is known about the potential impacts of railways. In particular, it is uncertain whether railways are an important mortality source when crossing wetlands heavily used by aquatic birds. Here we analyze bird collisions in a railway that crosses the Nature Reserve of the Sado Estuary (Portugal) over an annual cycle, documenting bird mortality and the flight behaviour of aquatic birds in relation to a bowstring bridge. During monthly surveys conducted on 16.3 km of railway, we found 5.8 dead birds/km/10 survey days in the section crossing wetland habitats (6.3 km), while <0.5 dead birds/km/10 survey days were found in two sections crossing only forested habitats. Most birds recorded were small songbirds (Passeriformes), while there was only a small number of aquatic birds (common moorhen, mallard, flamingo, great cormorant, gulls) and other non-passerines associated with wetlands (white stork). During nearly 400 h of observations, we recorded 27,000 movements of aquatic birds across the Sado bridge, particularly in autumn and winter. However, only <1% of movements were within the area of collision risk with trains, while about 91% were above the collision risk area, and 8% were below the bridge. Overall, our case study suggests that bird collisions may be far more numerous in railways crossing wetland habitats than elsewhere, although the risk to aquatic birds may be relatively low. Information from additional study systems would be required to evaluate whether our conclusions apply to other wetlands and railway lines.
Large-scale transportation infrastructures, such as high-speed railway (HSR) systems, cause changes in surrounding ecosystems, thus generating direct and indirect impacts on bird communities. Such impacts are rooted in the individual responses of birds to infrastructure components, such as habitat occupancy of railway proximities, the use of structural elements (e.g., perching or nesting sites), flights over the railway, and behavior towards approaching trains. In this chapter, we present the most important results of several studies that were carried out on bird communities, between 2011 and 2015 on a 22-km stretch of HSR built on an agrarian landscape in central Spain. Available data describe the abundance and spatial distribution of birds up to 1000 m from the railway, bird infrastructure use (e.g., embankments, catenaries), cross-flights of the railway obtained through focal sampling, and animal responses to approaching trains recorded from train cockpits. These data depict how bird species respond at various scales to the presence of the HSR, and show how the infrastructure impacts bird communities, due to both habitat changes and increases in mortality risk.
Train-wildlife collisions can impact wildlife populations as well as create human and resource management challenges along railways. We identified locations and railroad design features associated with train-wildlife collisions (strikes) on a 134 km section of the Canadian Pacific Railroad (CPR) that travels through the Banff and Yoho National Parks. A 21-year dataset of train strikes with elk (Cervus elaphus), deer (Odocoileus spp.), American black bears (Ursus americanus) and grizzly bears (U. arctos) were compared to relative abundance estimates, and nine train and railroad variables. Train strikes and relative abundance varied spatially for elk, deer and bears. Hotspots and relative risk estimates were used to identify potential problem locations. Hotspots were defined as segments of the train line where strike counts were above the 95% confidence interval based on a Poisson distribution, and could be identified for elk and deer but not bears. Relative risk was estimated as the ratio of strike counts to that expected based on relative abundance. High relative risk locations, where more strikes occurred than were expected, were identified for elk, deer, and bears. Relative abundance was positively correlated with strikes for elk and deer but not bears. Train speed limit was positively associated with strikes for elk and deer. For bears, the number of structures (e.g., overpasses, tunnels, snow sheds and rock cuts) and bridges were positively correlated to strikes. To reduce the risk of train strikes on wildlife, our management recommendations include train speed reduction, habitat modifications and railroad design alterations.
The extensive network of the Indian Railways cuts through several forested landscapes, resulting in collisions of trains with a variety of wildlife species, including the largest land mammal–the elephant. In India, railway lines cross elephant habitats in several states, with accidents that resulted in more than 200 elephant deaths between 1987 and 2015. As the 161-km Siliguri–Alipurduar track in the northern West Bengal state witnesses train–elephant collisions frequently, we developed a case study there with the objectives of mapping locations of collisions and generating a susceptibility map showing locations prone to accidents. We mapped elephant crossing points and movement paths along this railway track, as well as accident locations. Between 1974 and 2015, collisions occurred throughout the line, although there were several hotspots where elephant deaths were concentrated. A disproportionate number of accidents occurred during the night. Crop raiding in villages and train elephant accidents seem to be closely related, probably due to an increased frequency of elephant movement near or across this railway track during the cultivation season. Male elephants were much more prone to accidents, possibly because of behavioural characteristics that make them cross railway tracks more frequently. To reduce the frequency of accidents in this region, we recommend reducing the speed of trains, limiting the operation of trains during at night, provisioning overpasses and underpasses, using communications technology, realigning a portion of the track, and fencing the track except for corridor areas.
Linear transportation infrastructures may displace wildlife from nearby areas that otherwise would provide adequate habitat conditions. This exclusion effect has been documented in roads, but much less is known about railways. Here we evaluated the potential exclusion effect on birds of a railway crossing a wetland of international importance (Sado Estuary, Portugal). We selected 22 sectors representative of locally available wetland habitats (salt pans, rice paddy fields, and intertidal mudflats); of each, half were located either close to (0–500 m) or far from (500–1500 m) the railway line. Water birds were counted in each sector between December 2012 and October 2015, during two months per season (spring, summer, winter, and autumn) and year, at both low and high tide. We recorded 46 species, of which the most abundant (>70% of individuals) were black-headed gull, greater flamingo, northern shoveler, black-tailed godwit, and lesser black-backed gull. Peak abundances were found in autumn and winter. There was no significant variation between sectors close to and far from the railway in species richness, total abundance, and abundance of the most common species. Some species tended to be most abundant either close to or far from the railway albeit not significantly so but this often varied across the tidal and annual cycles. Overall, our study did not find noticeable exclusion effects of this railway on wetland birds, with spatial variation in abundances probably reflecting habitat selection and daily movement patterns. Information is needed on other study systems to assess the generality of our findings.
In 2007, the Portuguese Railway Company (REFER) began to build a new railway connecting the commercial port of Aveiro (Central Portugal) to the national rail network, which extended for about 9 km and crossed three of the remaining saltpans of the Aveiro Lagoon through a viaduct. Due to the importance of these habitats for shorebirds, and because the railway crossed a Natura 2000 site, the national biodiversity conservation authority required the impact assessment of this infrastructure. The study extended from 2006 (pre-construction), through 2008 and 2009 (construction), to 2011 (post-construction), encompassing four breeding and four wintering seasons. We used a Before-After-Control-Impact (BACI) design, with three impacted (those under the viaduct) and six control saltpans. During the breeding season (April–July) we monitored the numbers and breeding parameters of Black-winged stilt (Himantopus himantopus), and the numbers of Kentish plover (Charadrius alexandrinus) and Little tern (Sterna albifrons). In the winter, we monitored the numbers and spatial distribution of all shorebirds, and the activity of Dunlin (Calidris alpina). There was evidence for reductions in the abundance of the three breeding species in impacted saltpans in 2011, while no significant negative effects were found on abundances during 2008–2009 and on the breeding parameters of Black-winged Stilt. There was also evidence for reductions in wintering shorebird abundances in impacted saltpans in 2011, with no significant effects on abundances in 2008–2009, and on shorebird spatial distribution and activity patterns. Overall, the results suggest that the operation of a new railway close to important wetland habitats had negative impacts on the abundance of breeding and wintering shorebirds.
The aim of this study is to evaluate and mitigate the impact of a high-speed railway (HSR) line on functional connectivity for the European tree frog (Hyla arborea), an amphibian species highly sensitive to habitat fragmentation. The method consists of modeling its ecological network using graph theory before and after the implementation of the infrastructure and of evaluating changes in connectivity. This diachronic analysis helps visualize the potential impact of the HSR line and to identify areas likely to be most affected by the infrastructure.
Mongolia’s Gobi-Steppe Ecosystem is the largest grassland in the world and the habitat of long-distance movement ungulates, such as the Mongolian gazelle (Procapra gutturosa) and the Asiatic wild ass (Equus hemionus). The international railway between Russia and China bisects this habitat, and there has been concern that it may impede the movements of wild ungulates. We tracked ungulate movements on both sides of the Ulaanbaatar–Beijing Railway, and found that most of the tracked animals never crossed the railway. The construction of additional railways to permit mining projects in the area is therefore a further threat to maintaining the great migrations of ungulates across Mongolia.
The range of direct and indirect effects of railway transport on animals,
plants, ecological processes and the actual ecosystems vary considerably. Railway
transport operations and infrastructure building lead to environmental pollution,
loss or conversion of habitats, landscape fragmentation and, last but not least, to
animal mortality caused by collisions with passing trains. The impact of railways is
determined by the nature of railway infrastructure, which is not as significant in the
Czech Republic as road infrastructure, yet it is one of the densest in Europe. An
important feature is relatively low electrification (about 33% of the lines) and the
length of multi-track lines (about 20%). In the coming years, we can expect massive
investments in revitalization, optimization and modernization of the railways in the
Czech Republic, and eventually their electrification. To connect the crucial
trans-European lines and all regions it will be necessary to complete the basic
network of high-speed railways. Based on these facts we can say that the significance
of railway ecology in the Czech Republic will grow with the amount of
investment activities implemented in the railway network. In the past, similar
development took place with road infrastructure, and therefore there is an opportunity
to learn from it. To mitigate the direct effects of railways on wildlife, on the
basis of previous experience in the Czech Republic we recommend working primarily
with management measures. These are both in terms of wildlife management
and the management of habitats in the area of transport infrastructure.
This chapter presents the results of several studies realised between 2010 and 2014 on the French railway network. We assessed several potential ecological roles for this network on various taxa: (1) habitat, (2) corridor/longitudinal connectivity along railways and (3) barrier/transversal connectivity across railways. Our results show that railway verges, contrary to common belief, can have positive effects in anthropogenic landscapes for several taxa and communities. They can be habitats for semi-natural grassland plants, bats and orthopteran. They provide functional connectivity for some plants, but do not seem to increase it for highly mobile invasive species in urban landscapes. Railways also seem to be weaker barriers than roads for one butterfly species. We conclude by proposing a change in management practices, stressing that extensive management coupled with small-scale revegetation processes, either artificial or natural, may help increase the positive effects of railway verges and counteract the negative large-scale effects of urbanisation.
Since reliable accident statistics and consequent costs have become available, train collisions with wildlife, especially ungulates, have received increasing attention in Sweden. In contrast to collisions on roads, accidents involving wildlife on railways do not entail human injury or death, but can cause substantial train damage and lead to significant delays in railway traffic. Wildlife-train collisions (WTC) are rising in numbers and railways appear as a greater source of ungulate mortality per kilometer than roads. Nevertheless, railways are largely unprotected against wildlife collisions, and mitigation measures that have hitherto been applied to roads are either infeasible or economically unviable for railways. The Swedish Transport Administration is therefore seeking innovative and cost-effective measures for preventing collisions with larger wild animals. In this chapter, we present research on WTC in Sweden that has been used to define the baseline and set up criteria for a new mitigation project. This project aims to develop warning or deterring signals that encourage animals to leave the railway shortly before trains arrive. This will be carried out at several experimental crosswalks for animals along fenced railways where the effect of different signals on animal behaviour can be evaluated. If effective, these deterrent systems could replace fencing and/or crossing structures, and reduce mortality and barrier effects on wildlife. The project was begun in 2015 and will continue for at least 4 years.
While railroads figure prominently in U. S. history and culture, their environmental impacts are often overlooked. Here, I describe situations where operation and maintenance of a section of transcontinental railroad in Montana, USA, resulted in high mortality of grizzly bears (Ursus arctos), a threatened species under the U. S. Endangered Species Act, and where proposed avalanche control measures conflicted with the preservation mandates of Glacier National Park. A unique public/private partnership was created to work towards effective solutions to environmental problems. The partnership was successful in decreasing high grizzly bear mortality rates, but less so in finding a consensus on how best to reduce avalanche risk. I suggest that collaborative partnerships, such as that developed here, will be essential to solving future environmental problems associated with railroads.
As societies realise the importance of maintaining biodiversity and, accordingly, acknowledge the need for monitoring, minimizing and compensating the impacts of socioeconomic activities, including transportation, more scientists will be called to address these societal challenges. Railway Ecology is emerging in this context as a relatively new field to identify and provide solutions to the specific environmental problems associated with the building and operation of railways, particularly their impacts on wildlife. This is an interdisciplinary field that uses and draws methods from other disciplines, ranging from ecology and genetics, to statistics and computer simulations. Here, we summarize the guidelines to address railway-related biodiversity conservation problems as they were identified in the several chapters of this book, and recommend lines for future research.
... The railway was probably as attractive as roads for snakes, which may similarly explain gene flow enhancement observed in snakes. Railway embankments provide important alternative habitats for reptiles with optimal thermal conditions for basking (Borda-de-Água et al., 2017), especially when traffic density -and associated disturbance-is low, as it is the case here, with approximately 10 trains/day. Additionally, even active lines can harbor particularly high diversity in reptile species, notably because human presence is scarce and because reptiles can perceive vibrations transmitted through the rail tracks and the ballast when a train approaches, allowing them to reach a shelter before collision (Borda-de-Água et al., 2017). ...
... Railway embankments provide important alternative habitats for reptiles with optimal thermal conditions for basking (Borda-de-Água et al., 2017), especially when traffic density -and associated disturbance-is low, as it is the case here, with approximately 10 trains/day. Additionally, even active lines can harbor particularly high diversity in reptile species, notably because human presence is scarce and because reptiles can perceive vibrations transmitted through the rail tracks and the ballast when a train approaches, allowing them to reach a shelter before collision (Borda-de-Água et al., 2017). ...
Large-scale Transportation Infrastructures (LTIs) are among the main determinants of landscape fragmentation, with strong impacts on animal dispersal movements and metapopulation functioning. Although the detection of LTIs impacts is now facilitated by landscape genetic tools, studies are often conducted on a single species, although different species might react differently to the same obstacle. We surveyed four species (a snake, an amphibian, a butterfly and a ground-beetle) in a landscape fragmented by six LTIs: a motorway, a railway, a country road, a gas pipeline, a power line and a secondary road network. We hypothesized that LTIs carrying vehicles would mostly impact ground-dwelling species, possibly in a cumulative way. We showed that half of the overall explained genetic variability across all species was due to LTIs. While the butterfly was seemingly not impacted by any LTI, the genetic structure of the three other species was mostly influenced by roads and motorway. The power line did not affect any species and the gas pipeline only impacted gene flow in the ground-beetle through forest fragmentation, but roads systematically affected at least two species. Interestingly, we also showed that some LTIs could somehow promote gene flow, embankments probably providing favourable habitats for vertebrate species. Considering the high variability in species response to LTIs, we argue that drawing general conclusions on landscape connectivity from the study of a single species may lead to counterproductive miti-gation measures and that multi-species approaches should be more systematically considered in conservation planning.
... Habitat loss and fragmentation are two of the greatest ecological consequences of road network expansion. These environmental alterations start with the construction and extend during the operation of the road, which, in the long run, can produce a significant damage to biodiversity (Borda-de-Água et al., 2017;Frankel, 1974;González-Suárez et al., 2018;Jaeger et al., 2005;Tilman et al., 2001;Trombulak and Frissell, 2000;Madadi et al., 2017). Likewise, roads increase the span of disturbance caused by human activities, so that the impacts add up and influence habitats in an additive, multiplicative or compensatory manner (Darlington et al., 2022;Foley et al., 2016;Hodgson and Halpern, 2018). ...
Roads cause disturbances to wildlife from the beginning of their construction and once the road is in operation, people usually make use of the habitats, reducing their quality. To this are added the effects caused by light and noise from vehicles. These propagate through the land adjacent to the road causing changes in the fauna's use of the habitat. This led us to ask ourselves what attributes inherent to the road and terrain influence the vertebrate fauna and what factors associated with human activities can be considered as confounding variables for the results interpretation? The study was conducted in proximity of the 40D highway in Mexico. Three paired areas were selected where signs of wildlife presence were recorded during spring and fall from 2018 to 2020 and these data were used as response variable (2108 records of 49 species). We used as explanatory variables the inherent characteristics of the natural terrain and road (e.g., height difference between road and habitat, distance from road), as well as those related to human presence in the habitat (e.g., distance to nearest town). GLM's were adjusted to determine the influence of these on our response variable. We found that the inherent variables of the road and terrain have a significant influence on the number of faunal of hunting interest traces found (p = 0.018, r² = 23.09). The method used allowed us to identify and distinguish the influence that human activities exert on the fauna within the road's influence zone. The differential way in which organisms respond to human presence and activity makes it difficult to isolate this effect from the one we wish to evaluate, such as that of the road. Therefore, it is suggested that the variables used in this study be used as a control measure of this effect in the work carried out in proximity of roads.
The paper presents the results of the study of the influence of railway transport on the passing the fluorescence induction of chlorophyll in the leaves of broad-leaved linden (Tilia platyphyllos). The relevance of research is due to the increase in the intensity of the negative impact of transport on the environment, directly on phytocenoses, which causes a violation of physiological processes and leads to the failure of photosynthesis, which is very important for the vital activity of plants. Thus, the aim of the work was to study the influence of railway transport on the induction of chlorophyll fluorescence in the leaves of broad-leaved linden trees, as one link in the overall monitoring of the impact of railway transport on the environment. The passage of IFH in tree leaves was evaluated using the portable device "Floratest". Trees grown on the territory of the Holosiiv Park were used as controls, and trees growing on the territory of the locomotive depot "Ukrzaliznytsia" served as experimental samples. Measurements of chlorophyll fluorescence induction were carried out on leaves growing on the lower tiers of trees. Assessment of the physiological state of linden leaves under the influence of railway transport was carried out according to the main parameters of the Kautsky induction curve. It was established that the IFH indicators, such as F0, Fpl, F st, Fv, F max, in the trees growing on the territory of the locomotive depot exceeded the IFH indicators of the trees from the Holosiiv park, which is explained by the failure of the dynamic balance between the IFH processes and the violation of photosynthetic processes in the trees . According to the comparative analysis of IFH parameters in control and experimental samples of linden tree leaves, it can be concluded that the trees growing on the territory of the locomotive depot "Ukrzaliznytsia" were slightly stressed by possible noise, vibration and chemical pollution caused by the operation of the railway.
The biotic and abiotic components of ecosystems are altered by forest roads, which influence the temperature, humidity, wind speed, and light availability and alter the composition and diversity of plant communities. In this study, we aimed to examine and compare the diversity index of native and exotic species and soil chemical properties along the park's main forest routes in Lawachara National Park (LNP), the northeastern hill forest of Bangladesh. Ten transects were built along the main forest routes into the forest interior. Soil and vegetation data were collected along the transects with three sample plots each measuring 20 m × 20 m and placed at three different distances from the road's side (10 m, 50 m, and 90 m). The Shannon–Wiener index, species richness, Pielou's index, and density of all stems (DAS) were used as variables to determine the diversity of exotic and native plant species in each plot. The results revealed that the diversity indices and DAS for exotic species varied showing a negative correlation and declined their values as the distance from the roadside increased. However, the diversity indices and DAS for native species increased and showed a positive correlation with increasing distance from the road edge. Soil pH, organic matter, and index of disturbance severity (IDS) were also shown to be affected by the proximity of forest roads where the pH and IDS values decreased with increasing distance from the road to the interior forest indicating a negative relationship between distance and these variables. But there was a positive correlation between organic matter and distance from the road edge to the interior forest. Forest managers need to be aware of the potential effect of forest roads. Evaluation of the road-affected zone should be taken into account long term in the monitoring of forest ecosystem biodiversity by the forest authorities.
The railway sector is the largest branch of the economy in Kazakhstan. Nevertheless, environmental safety issues and the reduction and prevention of harmful impacts are not given sufficient attention. There is very little research on the impact of the railway sector of Kazakhstan on the natural environment, which hinders the further development of the railway sector and thus necessitates the addressal of environment issues. This study aimed to show possible environmentally hazardous sections of the country’s railway infrastructure. The criteria chosen for the analysis were soil cover, water resources, rainfall, protected natural areas, and population. A map of environmentally sensitive areas was created to determine which areas require priority protection from the environmental hazards posed by the country’s railway infrastructure. The map was developed in a GIS environment using the weighted overlay, expert assessment, and snowball methods. Additionally, a model for the Kazakhstan segment of the International Northern Railway Corridor was constructed in this article to identify integral indices that assess the susceptibility of the territory to environmental hazards. The data and results presented in the article can be used to solve current and future environmental issues concerning the country’s railway communications and can be implemented in many practical applications.
The paper presents the distribution of heavy metals in the roadside zone, using the example of sections of Russian railway lines with different intensity of train traffic. The research methodology involved constructing a mathematical model on the basis of experimental data, which makes it possible to estimate the distribution of pollutants over the zone. Mass transfer of dust particles during train passage is represented on the model of snow structures. The functional dependence for construction of the complete curve of contamination of the roadside zone depending on the coordinate of distance from the track axis was obtained. The model of mass transfer of dust particles makes it possible to estimate soil contamination in the roadside zone. It was established that on the basis of correlation of theoretical surface contamination with actual contamination, it is possible to draw a complete contamination curve by sampling points using the functional dependence of mass transfer obtained in the modeling. It was revealed that 70% of dust surface pollution accounts for the right-of-way, providing further maximum contamination with heavy metals of the upper layer of soils. Other 30% are distributed on a sanitary-protective zone and city soils. At the same time it is worth noting that the share of metals of the 1st class is insignificant in this distribution.
Nowadays challenges for ensuring an environmental friendly transportation system implies, we may say primarily, improving the railway quality and efficiency by taking account of modeling and simulation formalisms available for network analysis should be able to perform analysis of railway networks, provided that segment attributes and data base structures can be modified in a dynamic framework. The rethinking of the concept of railway will often start with a redesign of functional network optimization, i.e. how to adjust the railway concepts, the circulation of railway vehicles. An example of modeling railway systems using discrete event formalisms, i.e. Ramadge - Wonham formalism is presented and further development path of our approach is also mentioned in the last section of the article.
Land-based transport corridors and their related infrastructure increasingly extend into and across the Arctic in support of resource development and population growth, causing large-scale cumulative changes in northern socio-ecological systems. These changes result from the increased mobility of people, goods and resources, and from environmental impacts on landscapes and ecosystems as the human footprint extends into remote, unindustrialized regions. Arctic climate change is bringing new challenges for construction and maintenance of transport systems, requiring adaptive engineering solutions as well as community resilience to change. In this review article, we consider the complex entanglements between humans, the environment and land transportation infrastructure in the North, and illustrate these aspects by way of seven case studies: Baikal-Amur Mainline, Bovanenkovo Railway, Alaska-Canada Highway, Inuvik-Tuktoyatuk Highway, Alaska Railroad, Hudson Bay Railway and proposed railways on Baffin Island, Canada. As new infrastructure is anticipated and built across the circumpolar North, there is an urgent need for an integrated socio-ecological approach to impact assessment. This would include full consideration of Indigenous knowledge and concerns, collaboration with local communities and user groups in assessment, planning and monitoring, and evaluation of alternative engineering designs to contend with the impacts of climate change in the decades ahead.
Animal accidents on railway tracks have been menacing to the wildlife population. The main victims of this being the bigger and slower animals like elephants, rhino and buffalo. These accidents also causes damage to the railway infrastructure. Many solutions have been proposed, some solely depending upon sensors, some only consisting software solutions. But, since the inclusion of machine learning, both technologies are used to solve this existing problem. Deep learning being the latest innovation in field of machine learning has helped in the pre-existing solution. For classifying the images as animal detected on track or not, deep learning strategies have been highly efficient. The model discussed in the paper is based on convolution neural network (CNN). With the layers of CNN, there was normalization and pooling layers used to train the model with less loss. The dataset involved contains images of elephants, rhino and buffaloes in the wildlife. The dataset have less images due to non-availability of public datasets of railway tracks, as well as animals. The model was also compared with the other models with the help of transfer learning. The model gives accuracy of 96%.
Aim
The introduction of exotic plants can both increase (homogenize) and decrease (differentiate) floristic similarity between areas. We have a poor understanding of the degree to which plant species introductions tend to homogenize or differentiate floras, and relevant studies covering large spatial extent are scarce. China has been heavily invaded by exotic plants. Here, we analyse a comprehensive dataset of vascular plants to determine whether the introduction of exotic plant species has homogenized or differentiated species composition in regions across China.
Location
China.
Methods
We calculated the Jaccard index and Simpson index of similarity for each pair of province‐level regions for native and exotic species separately and jointly, and calculated a homogenization index for each pair of regional floras. We correlated species richness of native and exotic plants to climatic factors, and correlated the Jaccard index and Simpson index to geographic and climatic distances. We used variation partitioning analysis to determine the relative importance of geographic and climatic distances on species turnover. We also examined the effect of human population density on florisitic similarity of exotic species.
Results
We found that the geographic range of each species was, on average, larger for exotics than for natives; floristic similarity between regions was greater for exotics than for natives; the vast majority of pairwise regional floras have been homogenized; the introduction of exotic species has caused stronger biotic homogenization for pairwise floras with greater dissimilarity in their species composition; geographic distributions of exotic and native species were determined by different sets of climatic factors; and distributions of exotic species were determined by climatic factors more strongly, compared to those of native species. Human population density had a moderate effect on florisitic similarity of exotic species.
Main conclusions
The introduction of exotic plant species has homogenized regional floras across China. Because strong international trades between China and other countries and dramatic development of transportation systems are continuing in China, which help spread of exotic species, we predict that exotic species will continue to spread and will strengthen biotic homogenization in China.
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