742
The establishment of S. alterniflora was faster in those projects than in ours, colonizing in the first year post breach (mostly via seeds) and having spread throughout
the site by year 3 post (compared to 2 and 5 years post, respectively, for our project).
The presence of seedlings early on in those two projects is not surprising since the
water entering the restoration sites would have been moving over salt marsh beforehand and so be carrying seeds with it (compared to our sites which are open to the
Bay). As well, conditions may have been immediately suitable for seed germination
in those two projects, with the marsh elevation not being too low (the sites were
diked for less than two decades) and the soil having appropriate edaphic conditions
(since the sites were previously freshwater impoundments). Our project is thus
unique given how exposed our sites are to wave energy, in addition to the high tidal
amplitude; the time-scales of biological community establishment observed seem
reasonable for our latitude and hydrodynamic conditions.
21.5 Implications for Salt Marsh Restoration in Macrotidal
and Ice-Influenced Environments
21.5.1 Lessons Learned
Several lessons have been learned through the design, implementation and monitoring of this project that can be utilized for future salt marsh restorations in the region.
1. Planning for future (and not current) environmental conditions is paramount. As
the local rate of relative sea level rise is projected to increase in coming decades,
any dike re-alignment must provide sufficient accommodation space (i.e., the
distance between the old and new dikes) to give newly created salt marshes
enough time to accrete and possibly migrate landward in step with changes in
sea level. Creating wide salt marshes (>200 m) will also allow people living in
adjacent settlements to take full advantage of all the ecosystem services that salt
marshes provide, including buffering against erosion.
2. Partnerships and a proactive approach are very important. The partnerships
developed as part of this project have allowed for the success of the project and
will prove invaluable for the implementation of future projects. By having a network of contacts in place, future projects will benefit from a more rapid mobilization of resources, which is important. The current restoration project would
have benefitted from more timely planning and construction, as the rapid deterioration of the old dike has resulted in increased wave action on the developing
marshes. We suspect that this may have had a deleterious effect on the developing plant communities.
3. Monitoring with an investigative or research focus, rather than following a rigidly prescribed protocol, allowed us to observe and quantify several unexpected
phenomena (e.g., the importance of S. alterniflora seedling to plant spread).
L.K. Boone et al.
The establishment of S. alterniflora was faster in those projects than in ours, colonizing in the first year post breach (mostly via seeds) and having spread throughout
the site by year 3 post (compared to 2 and 5 years post, respectively, for our project).
The presence of seedlings early on in those two projects is not surprising since the
water entering the restoration sites would have been moving over salt marsh beforehand and so be carrying seeds with it (compared to our sites which are open to the
Bay). As well, conditions may have been immediately suitable for seed germination
in those two projects, with the marsh elevation not being too low (the sites were
diked for less than two decades) and the soil having appropriate edaphic conditions
(since the sites were previously freshwater impoundments). Our project is thus
unique given how exposed our sites are to wave energy, in addition to the high tidal
amplitude; the time-scales of biological community establishment observed seem
reasonable for our latitude and hydrodynamic conditions.
21.5 Implications for Salt Marsh Restoration in Macrotidal
and Ice-Influenced Environments
21.5.1 Lessons Learned
Several lessons have been learned through the design, implementation and monitoring of this project that can be utilized for future salt marsh restorations in the region.
1. Planning for future (and not current) environmental conditions is paramount. As
the local rate of relative sea level rise is projected to increase in coming decades,
any dike re-alignment must provide sufficient accommodation space (i.e., the
distance between the old and new dikes) to give newly created salt marshes
enough time to accrete and possibly migrate landward in step with changes in
sea level. Creating wide salt marshes (>200 m) will also allow people living in
adjacent settlements to take full advantage of all the ecosystem services that salt
marshes provide, including buffering against erosion.
2. Partnerships and a proactive approach are very important. The partnerships
developed as part of this project have allowed for the success of the project and
will prove invaluable for the implementation of future projects. By having a network of contacts in place, future projects will benefit from a more rapid mobilization of resources, which is important. The current restoration project would
have benefitted from more timely planning and construction, as the rapid deterioration of the old dike has resulted in increased wave action on the developing
marshes. We suspect that this may have had a deleterious effect on the developing plant communities.
3. Monitoring with an investigative or research focus, rather than following a rigidly prescribed protocol, allowed us to observe and quantify several unexpected
phenomena (e.g., the importance of S. alterniflora seedling to plant spread).
L.K. Boone et al.