LANDSCAPE OVERVIEW
photo credit: Hayden Tackley
|
When ResNet began, Landscape 1 was focused on understanding the trade-offs represented by shifts from agricultural dykeland to tidal wetland as a result of climate change adaptation decisions. Our baseline paper published in 2021 identified some knowledge gaps, and after five years of empirical research to fill those gaps, we see a more nuanced picture of complementarity rather than trade-offs that supports the value of the coastal adaptation option of managed dyke realignment (MDR). MDR keeps some dykeland and restores some tidal wetland, by selectively moving dykes landward and higher. Surveys with local residents suggest this is the most favoured option (over dyke removal or raising all dykes in situ), because this option keeps dykelands, dykes and tidal wetlands together—which local residents currently experience and value holistically—and retains access via dykes. Mi’kmaw people we spoke to supported tidal wetland restoration as critical to reconciliation, but also accepted the value of retaining some productive dykelands. We found that widening the tidal marsh extent in front of dykes increases wave dissipation, protecting dyke infrastructure and reducing the risk of overtopping and downward salt water intrusion, highlighting both the importance of protecting existing foreshore marsh and of restoring wetlands in front of realigned dykes rather than using that sediment to build up dykes. Dykeland farms can include valuable fruit and vegetable crops that require insect pollination. We found that native wild bee pollinators are essential for economic viability of apple and other crops, and that both dyke and tidal wetland habitats support the same bee species that pollinate crops in adjacent farms. Dykelands and adjacent tidal wetlands function together as part of an interactive working marshland landscape.
We do not see this direct complementarity for all services studied. Largely desk-based fisheries research indicates that tidal wetlands are critical nursery ecosystems for many species, including commercial ones, whereas dykelands provide no fishery habitat. However, dykes provide critical access for recreational fishing. Also, it is important to be aware that over the long term, dykelands may not remain agriculturally viable as sea levels rise. We used a new model and data from wells and geophysical instruments to show that subsurface saltwater intrusion into groundwater systems can occur under dykes and can impact groundwater resources for decades. We explored spatial and temporal variation in carbon densities in tidal wetlands and found the potential for rapid carbon accumulation following tidal restoration, with further additional increases in carbon density in older restoration or reference sites. By the end of the project in mid-2025 we hope to have better information about the net carbon implications of coastal adaptation decisions, as well as the impacts of such decisions on the Acadian diaspora. |
LANDSCAPE 1 TEAM
Kate Sherren she/her CO-LEAD Dalhousie University 
Alexandre Legault he/him MASTER'S STUDENT Dalhousie University 
Lisa Kellman she/her COLLABORATOR St. Francis Xavier University 
Aaron MacNeil COLLABORATOR Dalhousie University |
Jeremy Lundholm he/him CO-LEAD Saint Mary's University 
Danika van Proosdij she/her CO-APPLICANT Saint Mary's University 
Allison Walker she/her COLLABORATOR Acadia University 
Mark Mallory he/him COLLABORATOR Acadia University |
Kiirsti Owen she/her PhD student University of New Brunswick 
Claude DeGrace COLLABORATOR Landscape of Grand Pré 
Barret Kurylyk COLLABORATOR Dalhousie University 
Billie Lee Turner II COLLABORATOR Arizona State University |
Brittney Roughan she/her PhD student Saint Mary’s University 
Adam Campbell he/him COLLABORATOR Ducks Unlimited Canada 
Tony Bowron he/him COLLABORATOR CBWES Inc. 
Jennifer Graham COLLABORATOR Nova Scotia Department of Environment |
David Lapen COLLABORATOR Agriculture & Agri-Food Canada |
Megan Elliott she/her ALUMNa |
Nicole LeRoux ALUM |
Julia Guimond Alum |
Brandon Champagne alum |
Makadunyiswe (Maka) Ngulube alum |
Emily Wells they/she ALUM |
Tasha Rabinowitz ALUM |
Lara Cornejo ALUM 
Evan McNamara he/him ALUMNUS |
Polly Nguyen she/her ALUMNA 
Elise Rogers ALUM |
Kayla Williams she/her ALUMNA 
Samantha Howard she/her ALUMNA |
Kendra Sampson she/her Alumna |
PARTNER ORGANIZATIONS
Agriculture & Agri-Food Canada 
Nova Scotia Department of Lands and Forestry |
Nova Scotia Communities, Culture and Heritage 
CBWES, Inc. |
Nova Scotia Environment |
FEATURED PUBLICATIONS
|
Mega‐tidal and surface flooding controls on coastal groundwater and saltwater intrusion within agricultural dikelands
LeRoux, N.K., Frey, S.K., Lapen , D.R., Guimond , J.A., & Kurylyk, B.L.
Climate change will increase sea levels, driving saltwater into coastal aquifers and impacting coastal communities and land use viability. Coastal aquifers are also impacted by tides that control groundwater-ocean interactions and maintain an “upper saline plume” (USP) of brackish groundwater. Coastal dikes are designed to limit the surface impacts of high-amplitude tides, but, due to ongoing sea-level rise (SLR), low-lying dikelands and underlying aquifers are becoming increasingly vulnerable to flooding from high tides and storm surges. This study combines field observations with numerical modeling to investigate ocean-aquifer mixing and future saltwater intrusion dynamics in a mega-tidal (tidal range >8 m) dikeland along the Bay of Fundy in Atlantic Canada. Field data revealed strong connectivity between the ocean and coastal aquifer ...
|
|
Understanding multifunctional Bay of Fundy dykelands and tidal wetlands using ecosystem services—a baseline
Sherren K., Ellis K., Guimond J.A., Kurylyk B., LeRoux N., Lundholm J., Mallory M.L., Van Proosdij D., Walker A.K., Bowron T.M., Brazner J., Kellman, L, Turner II, B.L., & Wells E.
We review what is known about ecosystem service (ES) delivery from agricultural dykelands and tidal wetlands around the dynamic Bay of Fundy in the face of climate change and sea-level rise, at the outset of the national NSERC ResNet project. Agricultural dykelands are areas of drained tidal wetland that have been converted to agricultural lands and protected using dykes and aboiteaux (one-way drains or sluices), first introduced by early French settlers (Acadians) ...
|
|
High sedimentation rates lead to rapid vegetation recovery in tidal brackish wetland restoration
van Proosdij D., Graham J., Lemieux B., Bowron T., Poirier E., Kickbush J., Ellis K., & Lundholm J.
Introduction: Tidal wetland restoration in the Bay of Fundy involves restoring tidal hydrology to sites with tidal restrictions. Most have focused on salt marsh sites close to the mouth of estuaries, but there are also many tidally restricted wetlands closer to the freshwater end of tidal rivers. Recovery of salt marsh vegetation has been rapid in past projects, but little is known about sediment and vegetation dynamics post restoration in tidal brackish or freshwater environments.
Methods: We implemented tidal wetland restoration projects on two tidal rivers near the inland limit of saltwater. Hydrological restoration involved breaching (St. Croix) or realigning agricultural dykes (Belcher Street). We monitored hydrology, sediment accretion and vegetation at replicated plots on restoration sites and nearby reference tidal marshes; and conducted habitat mapping and elevation surveys using drones ... |
