Vegetation of railway verges in France
The studies described in this chapter were conducted along railway verges. Railway
verges are all the green areas that are beside the railway tracks. The total area
occupied by railway verges in France is estimated by the railway owner, the SNCF
Réseau company, at 50 000 hectares. The vegetation type on these green spaces is
dictated by security reasons. Management is thus necessary but different in different
parts of the railway concerned:
– Tracks and lanes: the goal is the absence of vegetation to avoid platform/
infrastructure deterioration. Total weed control is recommended once a year but
depends on the age of the infrastructure. For instance, a recent track, better drained,
is less sensitive to plant colonization and is usually not treated for 10 year;
The verges can be separated in two main zones:
– The first zone is adjacent to the tracks and has variable width depending on the
slope and surrounding landscape. Here the objective is to have an herbaceous
vegetation to allow visibility and limit fire problems. These semi-natural
grasslands are ideally managed by annual or multi-annual mowing depending on
fire risks and on potential recolonisation by woody species;
– In the second zone, the desired vegetation can be higher depending on their
configuration: if the verge is lower compared to the tracks (fill section), the trees
and shrubs are allowed to grow higher compared to a configuration where the
verges are higher than the tracks (cut section). Management here does not need
to be intensive and can be done every 3–5 years depending on the slope and the
vegetation in the surrounding landscape.
We examined two types of railways: recently built high-speed railway lines
(1994 and 2007) and long-established railway lines (built in the nineteenth century).
In the high-speed lines, we studied verges from 10 to 20 m-wide, composed of
herbaceous species and shrubs. No vegetation management plan existed for these
verges. Clearcutting of trees and mowing were applied on a case-by-case basis
when presenting threats for train security, e.g. risk of tree falling on overhead lines.
The long-established lines traverse a landscape structured by different degrees of
urbanisation, as they cross numerous cities and towns from the centre of Paris
towards the limits of the region. The vegetation found along the borders of the train
tracks is mainly spontaneous as the verges have not been planted or sown since
their construction and is principally interrupted by railway stations and overpasses.
Roles of Railway Verges: Habitat, Corridor, Barrier
Railways as Habitats
Linear infrastructures can be substitution habitats for various taxa (O’Farrell and
Milton 2006; Ries et al. 2001), however, hardly any studies focused properly on
16 Ecological Roles of Railway Verges in Anthropogenic Landscapes …
263
The studies described in this chapter were conducted along railway verges. Railway
verges are all the green areas that are beside the railway tracks. The total area
occupied by railway verges in France is estimated by the railway owner, the SNCF
Réseau company, at 50 000 hectares. The vegetation type on these green spaces is
dictated by security reasons. Management is thus necessary but different in different
parts of the railway concerned:
– Tracks and lanes: the goal is the absence of vegetation to avoid platform/
infrastructure deterioration. Total weed control is recommended once a year but
depends on the age of the infrastructure. For instance, a recent track, better drained,
is less sensitive to plant colonization and is usually not treated for 10 year;
The verges can be separated in two main zones:
– The first zone is adjacent to the tracks and has variable width depending on the
slope and surrounding landscape. Here the objective is to have an herbaceous
vegetation to allow visibility and limit fire problems. These semi-natural
grasslands are ideally managed by annual or multi-annual mowing depending on
fire risks and on potential recolonisation by woody species;
– In the second zone, the desired vegetation can be higher depending on their
configuration: if the verge is lower compared to the tracks (fill section), the trees
and shrubs are allowed to grow higher compared to a configuration where the
verges are higher than the tracks (cut section). Management here does not need
to be intensive and can be done every 3–5 years depending on the slope and the
vegetation in the surrounding landscape.
We examined two types of railways: recently built high-speed railway lines
(1994 and 2007) and long-established railway lines (built in the nineteenth century).
In the high-speed lines, we studied verges from 10 to 20 m-wide, composed of
herbaceous species and shrubs. No vegetation management plan existed for these
verges. Clearcutting of trees and mowing were applied on a case-by-case basis
when presenting threats for train security, e.g. risk of tree falling on overhead lines.
The long-established lines traverse a landscape structured by different degrees of
urbanisation, as they cross numerous cities and towns from the centre of Paris
towards the limits of the region. The vegetation found along the borders of the train
tracks is mainly spontaneous as the verges have not been planted or sown since
their construction and is principally interrupted by railway stations and overpasses.
Roles of Railway Verges: Habitat, Corridor, Barrier
Railways as Habitats
Linear infrastructures can be substitution habitats for various taxa (O’Farrell and
Milton 2006; Ries et al. 2001), however, hardly any studies focused properly on
16 Ecological Roles of Railway Verges in Anthropogenic Landscapes …
263