Many hidden ecological services
Rain gardens don’t just manage stormwater runoff. Here’s an amazing secret: they provide other invaluable ecological services!
1. Managing stormwater runoff
First, on top of reducing the “water hammering" intensity of sudden showers, rain gardens improve water quality before it reaches groundwater and streams. By implementing rain gardens in multiple areas of lake Waterloo’s watershed, we can reduce the phosphorus mineral reaching the lake. This would be a significant gain considering that 53% of the external contributions of phosphorus into lake Waterloo come from urban runoff.
Phosphorus mineral reduction is the primary goal of Les Amis du bassin versant du lac Waterloo, rain garden project
The management of stormwater is of concern to the ministry of the environment and the fight against Climate Change. Consult the impacts of stormwater runoff and the measures the Government of Quebec is putting in place to mitigate them.
2. Collection of the phosphorus by the rhizophere
Plants in rain gardens absorb some of the phosphorus to feed and grow. But they’re not the only ones doing this job! They actually have some very effective microscopic allies!
There is a high-performance factory embedded in the plants’ roots. This factory is called the rhizosphere! It is formed and affected by the soil at the roots. The workers at this factory are microorganisms: microscopic bacteria and fungi.
The function of the factory (the rhizosphere) is to promote exchanges between the workers (microorganisms) and the plants. The result of these exchanges is the modification of the physical and chemical properties of the soil, among which the absorption of part of the phosphorus. Nature never ceases to amaze us!
Learn more about the rhizosphere
The benefits of rain gardens don’t stop here.
3. Promoting biodiversity
photo Sabine Vanderlinden
Intelligent gardens increase the biodiversity of residential land by creating a space conducive to the flora and to the wildlife albeit at a smaller scale.
4. Attracting pollinisators
Pollination is one of the greatest gifts of nature. If we think about it for a moment, it is quite remarkable: insects, bees, butterflies, hummingbirds too, travel from plant to plant, generating pollen in the air allowing plants to produce seeds and fruits.
(The more scientific explanation is that the transfer of pollen from the stamens, the male reproductive organs of plants, to the pistil, the female reproductive organ of plants, promotes the fertilization of seeds and fruits, as per the e-magazine Du jardin dans ma vie)
Isn’t it extraordinary?
Well, rain gardens are popular with pollinating insects. Especially if your choice of plants contains fruit shrubs.
photo Sabine Vanderlinden
