Environmental Assessment
Volume C-6
Slurry Pipeline
Reclamation and Closure
Ambatovy Project
208
January 2006
6.1.5
Revegetation
Natural revegetation will be encouraged throughout the project area. Seed types
that are currently available in sufficient quantities often consist of highly
competitive agronomic species that are not indigenous to the area and may out-
compete regenerating and re-colonizing native flora, especially in the early seral
stages of secondary succession. Consequently, to maintain the ecological
integrity of the project area, only disturbed sites that are susceptible to erosion be
seeded (i.e., stream banks).
Additional forest restoration will occur over the full pipeline RoW immediately
following construction between the edge of the mine plant site and pipeline
kilometre point 2, and between pipeline kilometre points 16 and 26. These
segments are of particular importance due to their proximity to existing high
quality forest corridor areas and the Torotorofotsy Wetlands. Rapid revegetation
of these RoW segments will ensure that habitat connectivity is maintained and
visual effects are minimized. In these areas, the goal will be the restoration of
native zonal forest, through a series of revegetation phases, beginning with
erosion-control ground cover. As described in Volume C, Section 4.1, a research
program to investigate the success of different reclamation techniques may be
undertaken in some areas.
On level and gently sloping terrain, and where specified, slash will be rolled back
to minimize erosion and encourage natural revegetation from the soil seed bank
and adjacent areas. Reclamation and flora regeneration on access routes, and
unused areas of the road and borrow pits, will be enhanced by the seeds and other
propagules contained in the natural seed bank (upper portion of the soil profile),
as well as through natural colonization and encroachment from adjacent,
undisturbed plant communities.
Exposed areas and steep slopes will be revegetated with a self-sustaining, erosion
controlling seed mix appropriate to the region. It is suggested that Vetiver grass
(
Vetiveria zizanioides
) be planted in strips across slopes (following contour lines)
(NRC 1993). Other species can then be planted between the strips of Vetiver.
A monitoring program will be implemented to determine the success of natural
revegetation. If natural regeneration is not sufficient, remedial seeding will be
completed on a site-specific basis.
The effectiveness of reclamation efforts will be monitored until satisfactory
reclamation conditions prevail. Site inspections will be completed regularly to
evaluate reclamation work and undertake remedial reclamation as necessary.
