where the experience on linear infrastructures of railway ecologists may prove
instrumental, namely due to their knowledge on the species and habitats that can
persist in railway verges in urban and suburban settings (see Chap. 16).
Railways Travel Towards Environmental Sustainability
As with any other means of transportation, there are environmental issues associated with railways, ranging from wildlife mortality, barrier effects, introduction of
exotic species, and several forms of pollution. Some of these are comparable to
those found in roads and other linear infrastructures, while others are railway
specific. Likewise, some mitigation measures can be adapted from road and power
line infrastructures, while others have to be developed specifically for railways. As
highlighted throughout this book, information is still in short supply for the evaluation and mitigation of impacts specific to railways, which justifies the need to
continue investing in research programs targeting railway ecology on its own right.
Based on the collective experience of this book we suggest that the following
research lines should be the priority focus of such programs, which will greatly
contribute to help keep railways on track towards environmental sustainability:
• First and foremost, studies to evaluate the biodiversity impacts of railways and
their mitigation measures need in most cases to be strengthened through the use
of adequate designs, sufficiently large sample sizes, and sufficiently long time
frames. Ideally, BACI (Before-After-Control-Impact) designs should be used to
examine such impacts, avoiding simple designs that have little power to
demonstrate causality (Balkenhol and Waits 2009; Corlatti et al. 2009; Soanes
et al. 2013; see Chap. 12). Monitoring must be long-term, as some species need
time to get used to disturbances associated with railway operation, and to the
implementation of mitigation measures (Baofa et al. 2006; Yang and Xia 2008;
Corlatti et al. 2009; Soanes et al. 2013).
• Second, we still need better estimates of wildlife mortality in railways, though
this is one of the most visible and well-studied impacts. Tackling this problem
will require, for instance, field experiments on searcher efficiency and carcass
persistence on railways (Barrientos et al. in review). These are expected to be
railway-specific because, as commented in Chap. 1, traffic flow on railways is
markedly lower than that of roads. This is important because low traffic flows
allow time gaps for scavengers to have access to carcasses. On the other hand,
trains travel over rails, and corpses falling out of them can persist longer as there
is no flattening as it may happen in roads.
• Third, we need a better understanding on the barrier and fragmentation effects of
railways, and how these may act together with those of other linear structures
such as roads (see, e.g., Chap. 14). Concurrently, we need to know where, when
and how can wildlife passes effectively mitigate such barrier and fragmentation
effects, by helping to restore connectivity across the landscape. A range of
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instrumental, namely due to their knowledge on the species and habitats that can
persist in railway verges in urban and suburban settings (see Chap. 16).
Railways Travel Towards Environmental Sustainability
As with any other means of transportation, there are environmental issues associated with railways, ranging from wildlife mortality, barrier effects, introduction of
exotic species, and several forms of pollution. Some of these are comparable to
those found in roads and other linear infrastructures, while others are railway
specific. Likewise, some mitigation measures can be adapted from road and power
line infrastructures, while others have to be developed specifically for railways. As
highlighted throughout this book, information is still in short supply for the evaluation and mitigation of impacts specific to railways, which justifies the need to
continue investing in research programs targeting railway ecology on its own right.
Based on the collective experience of this book we suggest that the following
research lines should be the priority focus of such programs, which will greatly
contribute to help keep railways on track towards environmental sustainability:
• First and foremost, studies to evaluate the biodiversity impacts of railways and
their mitigation measures need in most cases to be strengthened through the use
of adequate designs, sufficiently large sample sizes, and sufficiently long time
frames. Ideally, BACI (Before-After-Control-Impact) designs should be used to
examine such impacts, avoiding simple designs that have little power to
demonstrate causality (Balkenhol and Waits 2009; Corlatti et al. 2009; Soanes
et al. 2013; see Chap. 12). Monitoring must be long-term, as some species need
time to get used to disturbances associated with railway operation, and to the
implementation of mitigation measures (Baofa et al. 2006; Yang and Xia 2008;
Corlatti et al. 2009; Soanes et al. 2013).
• Second, we still need better estimates of wildlife mortality in railways, though
this is one of the most visible and well-studied impacts. Tackling this problem
will require, for instance, field experiments on searcher efficiency and carcass
persistence on railways (Barrientos et al. in review). These are expected to be
railway-specific because, as commented in Chap. 1, traffic flow on railways is
markedly lower than that of roads. This is important because low traffic flows
allow time gaps for scavengers to have access to carcasses. On the other hand,
trains travel over rails, and corpses falling out of them can persist longer as there
is no flattening as it may happen in roads.
• Third, we need a better understanding on the barrier and fragmentation effects of
railways, and how these may act together with those of other linear structures
such as roads (see, e.g., Chap. 14). Concurrently, we need to know where, when
and how can wildlife passes effectively mitigate such barrier and fragmentation
effects, by helping to restore connectivity across the landscape. A range of
314
R. Barrientos et al.