BCIT Natural Resources faculty Julia Alards-Tomalin and retired former BCIT Forest and Natural Areas Management Instructor Jace Standish have been working on research to help improve understanding around identifying wetlands in the Lower Mainland Fraser Valley (LMFV). Their research, published in the Journal of Wetland Science and Practice (October 2022), found that vegetation was reliable for identifying wetlands in the LMFV region.
Significance of the Lower Mainland Fraser Valley region
The Lower Mainland Fraser Valley is a complex and high stakes environment for wetland identification. The combination of high precipitation, subdued topography, and complex site history make wetland identification and management a challenging endeavor.
Over the last 100 or more years, the LMFV has undergone intense and rapid changes due to urban development. Originally the land was a natural assortment of bogs, swamps, and upland forests, which was then cleared for agriculture. Now, land use competition is intense and the stakes are high. The proper identification of wetlands can make or break development deals, so improving the ability to describe these important ecosystems is a timely issue.
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The effectiveness of vegetation for identifying wetland sites
The purpose of the research was to assess the effectiveness of vegetation for identifying wetland sites in the LMFV region. Describing the vegetation is one way to determine if a site is a wetland or not. Wetlands are defined as areas that are water saturated long enough to create soils with low oxygen levels and grow water-loving vegetation. When trying to identify wetlands, it’s important to examine these three traits:
- the hydrology of the site,
- the soil characteristics,
- and the vegetation community.
Unfortunately, for many sites in the LMFV, it is difficult to get sufficiently detailed information on wetland hydrology and soils. Disturbance and drainage have also drastically altered soil profiles.
There have also been concerns about relying on vegetation for identifying wetlands, as many LMFV plant communities are dominated by a small number of aggressive, seral species like reed canary grass. However, after collecting and analyzing data from a wide range of sites across the LMFV, vegetation was found to be reliable for identifying wetlands in the region. Nonetheless, disturbed sites will continue to be a challenge for wetland identification, and all three factors (hydrology, soils and vegetation) should be considered to ensure the most accurate results.