Why speak about nature in a site dedicated to history?
The natural environment, it’s fauna and flora, accompanied the development of the region and was witness to many changes since the arrival of the first settlers, more than a century ago.
The quality of the environment of lac Mercier is one of it’s main richness, and makes it a jewel in the region. The natural habitats and the fauna of the lake watershed make up a heritage that must be jealously preserved.
Wildlife habitat at lac Mercier:
Very useful information on how to protect wildlife habitats can be found in a presentation by AGIR pour la Diable, published in Summer 2012:
During the winter, bird-watching can become an interesting pastime.
If you decide to attract birds by feeding them at the start of Winter, you must continue until Spring. For these pleasant visitors, the availability of food becomes a question of survival.
Photos: France Grondin
It is strongly recommended, NOT to feed deer during any season. Attracting them close to dwellings increases the risk of collision with cars.
Also, deer greatly enjoy eating newly-planted bushes along the regenerated shoreline, as well as those used only for landscaping.
We should respect their habitat.
Do you know what a fox track looks like ?
The maintenance of an undisturbed shoreline strip is one of the factors that improve the water quality, and wildlife habitats, around the lake.
Because rain water runoff is slowed by roots, branches and trunks, it is filtered before entering the lake. The shoreline strip is the last filter for runoff before it enters the lake. It is also the last buffer against waves and erosion if it is made up of flowering plants, trees and shrubs.
A lush shoreline strip imparts a natural character to the environment, and increases property values.
Where shoreline regeneration is required, some native plants are particularly successful in naturalization of shorelines. These are pioneer plants well adapted to our climatic conditions, including ease of reproduction and resistance to manipulation.
Some good choices for this purpose are: alder, dogwood, sweet gale, the vine virgin, willow and spirea shrub with large leaves.
Hereunder are the pictures of a few varieties that are recommended:
The Myrica gale, also called Sweet Gale or Sweet Bayberry is also called “wood-feels-good”, meaning its generic name besides “fragrance.”
“Myrica gale” growing 1 meter high, very resistant, tolerates being flooded during long periods and spreads easily.
This shrub reaching 1 m high spreads very easily (seeds), is well adapted to our climate, may tolerate prolonged flooding and grows in poor environments (sandy banks) which makes it an ideal shrub for shoreline recovery .
Erosion of the shoreline :
Lac Mercier is especially vulnerable, because more than 50% of it’s shoreline lies adjacent to the linear park.
Anti-erosion reforestation efforts have been made in 2012 to several portions of the shoreline.
Main species of aquatic plants present in the lake:
A few plants are invasive:
Characteristics of invasive plants
Why do they become invasive? In lakes, these plant species become invasive because they can quickly spread. They have been known to crowd out native plants, and create dense mats that interfere with recreational activity. Invasive plants reproduce by different mechanisms:
-Seeds are produced, many of which lie dormant for a long time and germinate sporadically, leading to the conclusion that this is sexual reproduction
-Established plants can also spread by producing stolons that come from the root crowns and can produce a new plant up to 1 m away
-The method of spread is asexually from stem fragments that become brittle and break apart in the fall.
These fragments can float long distances to new areas, and settle to become a new plant.
Recreational activities (such as boating), and other disturbances, can carry stem fragments to other areas or bodies of water to create new plants.
The following 3 types of invasive plants are found in lac Mercier: *** Eurasian water milfoil (Myriophyllum Spicatum)
Eurasian water milfoil was introduced to North America nearly 50 years ago, and it has become an undesirable invasive species in many lakes.
Eurasian water milfoil reproduces from seeds. It also spreads by stolons from the roots.
The primary method of spread is by regrowth of plant fragments, which increases the rate in which the plant can spread and grow.
This is a submerged plant that grows quickly, and once the stems hit the water surface, they branch in all different directions to produce a dense mat of vegetation that blocks sunlight for plants below the surface.
These plants can easily cover a lake surface, from shore to shore.
Because of its ability to out-compete native plant species, a mono culture is created, and aquatic plant diversity can decrease.
These thick mats of vegetation can add more phosphorous and nitrogen to the water column, and alter water quality by raising pH and temperature and decreasing dissolved oxygen, making for a poor habitat for fish, waterfowl and other species.
Eurasian water milfoil can interfere with boating, fishing, and swimming, when one encounters the dense mats of vegetation. The vegetation can become entangled in boat propellers and boating equipment. It is found in sand, rocky and in soft sediments, in depths from a few centimeters up to several meters.
They root in sediment, sand, gravel, and vegetation debris, at depths varying from a few centimeters, to several meters of water.
The stems commonly grow to lengths of six to nine feet. The very small soft leaves, about two inches long, are deeply divided, resembling feathers.
It grows to the surface, and branches out to several secondary stems creating a dense mass. It’s very small white or reddish flowers, and it’s dark brown fruits form spikes which are held above the water.
*** Elodea nuttallii (western waterweed)
These underwater perennial plants grows less than 1 m long, with slender, generally branched trailing stems.
Elodea nuttallii is found in sandy and in soft sediments, in depths of up to several meters. Leaves are pale green, folded along the midrib, and somewhat re-curved with their tip tapered to a slender point. Small white flowers occur at the ends of long, thread-like stalks, blooming from July to September. Male flowers detach and become free-floating.
The shoots grow rapidly towards the surface without splitting, where they form a densely branched canopy. When water temperatures become warmer, the plant start to regenerate new lateral shoots. They propagate by stem fragments, over wintering buds, and rarely by seeds.
*** Broad-leaved Pondweed (Potamogedon amplifolius)
This native plant is one of the most invasive species in our lakes.
Broad-leaved pondweed grows amongst the submerged plant community. It is found in soft sediment soil, at depths from two to four meters.
The stalks of the floating oval large leaves are generally quite long, arched and folded.
The usually wavy-edged underwater leaves are curved into a banana shape, and oval, leathery floating leaves grow on or near the water surface. The small green-brown flowers, followed by fruit, occur among the floating leaves, and are densely arranged on an emergent dense spike.
*** Ribbon-Weaved Pondweed (Potamogedon epihydrus)
Field office guide to plant species. Northeast National Technical Center, Chester