THE ABOITEAU PARC DUNE CONSERVATION PROJECT
Transcription
THE ABOITEAU PARC DUNE CONSERVATION PROJECT
THE ABOITEAU PARC DUNE CONSERVATION PROJECT A project by : In partnership with : Context setting The Aboiteau Park dunes have, in recent years, undergone considerable modifications. Primarily, they have been subjected to erosion caused by the storms . The amplitude of the problem is such that a vast breach has been formed in the dune. This breach weakens the dune system which can therefore endanger the salt marshes located behind the dune. The Aboiteau conservation project has three main segments: In order to reverse this trend, the Cap-Pele Watershed Group has undergone various conservation activities on the Aboiteau dunes. Replanting Protection Regeneration Awareness Following is a glimpse of the various activities accomplished up to this point. Section of the Aboiteau dune affected by storm erosion REPLANTING In total, over 800 Marram grass seedlings were planted on the dunes during the month of June 2006. By producing important root systems, marram grasses considerably increase de dune’s stability and thus accelerate its regeneration. They also offer the dunes a form of protection against erosion caused by wind and rain. Marram grass(Ammophila breviligulata) Marram grass plantation PROTECTION Considering marram grass’s relatively high sensitivity to trampling, it is very important to minimize traffic on the dunes. In fact, we only need to walk10 times on a marram grass to destroy it. The Cap-Pele Watershed Group has therefore decided to install various structures aimed to reduce visitors’ access to the Aboiteau Park dunes. Signs Signs forbidding walking on the dunes have been installed in several spots of the beach. Snow fence Over 1500 feet of snow fence has been raised in front of the dunes. The snow fence has shown to be the most effective means to reduce traffic on the dunes. The fence is installed in spring and is removed in autumn. This assures it will not be damaged during our big winter storms. Snow fence REGENERATION It is possible to encourage the natural regeneration of a dune by placing vegetation barriers at its base. The use of Christmas trees for example, can promote dune nourishment by trapping windblown sand. For these reasons, the Cap-Pele Watershed Group has installed rows of fir trees next to the section of the dune which suffered the breach. A simple but effective method There are three important factors to consider when installing a vegetative barrier. 1) Picking a tree: conifers (firs, spruces), with their high density of branches and needles, are surely the best types of trees to catch and retain sand. 2) The barrier’s axis: to maximize dune regeneration, it is preferable to install the barrier in parallel with the dune. 3) The barrier’s strength: in order for the barrier to resist to high tides, it is important that it is well attached to the ground. It is thus necessary to firmly attach the trees end to end and to posts driven in the ground. The barriers 2 months after they were installed The barriers three months after they were installed • While the trees do trap sand between their branches, they also have the tendency to generate an important accumulation of sand behind the row of trees. • Also, during high tides, the trees have the capability to let water pass through while at the same time retaining sand. • Finally, it’s in the fall that we find the wind conditions that best favor sand accumulation. Sand trapped in the barriers Sand accumulated behind the barriers Awareness signs Since enhancing visitors’ awareness towards the Aboiteau Park Dune Conservation Project is an important element of this project, the Cap-Pele Watershed Group has created awareness signs that will be installed next to access points and catwalks. Finally, an information leaflet on the project has been produced with over 1500 copies distributed to visitors. Awareness sign of the Aboiteau Park dunes Interesting web sites : http://www.csmonitor.com/2004/0203/p02s01-usgn.html http://www.time.com/time/reports/environment/heroes/tfk/0,2967,tfk_sea shores,00.html http://www.snh.org.uk/publications/online/heritagemanagement/erosion/appendix_1.3.shtml http://www.landandwater.com/features/vol49no3/vol49no3_1.html www.usace.army.mil/cw/cecw-cp/news/pa_newsletter/v8i3.pdf http://www.lpyc.org.uk/dunes.htm