By Chris Borowski Strategic Watershed Action Team Crew Leader
You may be thinking to yourself, “what is a seed bank; a vault for seeds?” Well in simple terms, Yes! It’s an area where seeds are stored in a dormant state until needed. These seed banks can be artificial or naturally occurring. Artificial seed banks are storage facilities where seeds of different species are stored to preserve genetic diversity for the future. These seeds are stored in sub-freezing conditions and low humidity to prevent the seeds from spoiling and germinating. The second type of seed bank is a naturally occurring process where seeds are distributed through the soil but prevented from sprouting and so lay dormant until an environmental cue tells the seeds it’s time to start growing.
Over the seasons seeds are blown and dispersed from native vegetation into the soil, water, and organic material in the neighboring vicinity building up the seed bank. The seeds lay beneath the soil, waiting for their great escape until one day something happens, a disturbance in the area, the removal of a dam. New ground is exposed! “Sprout, sprout, sprout” the seeds think to themselves. “This is our time!” This brings us to our SWAT summer experiences with native seed banks.
In June of 2021, SWAT found themselves in Markdale, Ontario on site of the old Town Pond Dam. With only a few types of grass sprouting from the now exposed soil after the removal of the old dam in 2020, the team planted native shrubs and tree species to help stabilize the soils and provide shade for Armstrong Creek. In August the team returned to see how their plants were fairing the summer heat and that’s when they saw that a transformation had taken place. Years upon years of seeds being deposited into the old pond had created a seed bank of native flowers and sedges. The once barren land was now a meadow of flowers and pollinators.
The next experience came after SWAT worked together with Ignatius Jesuit Centre staff towards a common goal of restoring Brook Trout habitat on Marden Creek in Guelph, Ontario. Over the years the stream had become shallow from silt and sediment depositing from the neighboring fields. The team installed sediment traps constructed from recycled Christmas trees to narrow the creek and create new banks for shade and habitat. After construction, the team used their trusty shovels and began removing excess sediment from the channel to throw on top of their newly created sediment traps. The idea was to use the natural seed bank from the neighboring grasses, Jewel weeds and rushes to help initiate the establishment of vegetation. Fast forward to the end of August, during a site inspection, native grasses had already begun to grow from the seed banks! These naturally occurring seed banks can be a restoration dream or nightmare depending on what seeds lay dormant in the soil. The nightmare occurs when the soil contains non-native and invasive seeds that out-compete native species, creating a lot of problems for the local ecosystem. Stay tuned for more about these species in one of our upcoming articles!
With our experiences this summer working with native seed banks, their importance has built upon our values of restoring sites to their original states. The team looks forward to reviewing these areas in the future and restoring more of our freshwater resources.
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