Water resource in Canada ?

Question

someone told me today, if you take a look at of the Canada`s map, you will find numerous of small lakes instead of 10 or 20 large lakes , adn theese lakes are really vulnerable to climate change or human acitivy ( becasue they are too small and can not be considered as an ecosystem )

it is that true ?

Answer 1

That is actually two questions.  And I will answer them as that because there is not one answer that covers both of them.

Firstly, Yes, any lake is vulnerable to climate change and human activity; however, you also have to realise that the lake within Canada are transient.  All lakes when left to their own have a limited life cycle, they will all eventually disappear.  But unlike humans who's life span is measured in decades, a lakes lifespan is measured in millennia.

Eutrophication is the process that brings about the death of a lake.   Algal blooms, weeds, and other organic matter eventually die and decay and as such sink to the bottom of the lake. Combined with dust, pollen, minerals and other natural inputs, the decaying organisms build up from the lake bottom forming sediments. As the lake slowly fills up around its edges it loses surface area, but at the same time it loses depth and becomes smaller and smaller until it has been filled in completely.  During the process some lakes become swamps and various other wetlands.

So now that you know there is a natural cycle, think about the question you ask.  If the climate warms and more airborne particulate (ash, soil, pollen, etc.) are added to a lake as well as more evaporation from the lake itself, you see that the natural process is exacerbated.  At the same time if people begin damming waterways or extracting water, water levels fluctuate as well leading to a reduction of water and a quicker death to the lake.

As for the lakes being too small to be considered an ecosystem, this is blatantly incorrect.  On a strictly simple level, an ecosystem is defined as "A community of organisms and the physical environment in which they interact".  The term organism is a very broad term which includes protozoa (single celled organisms) to large trees (giant redwood).  In the strictest sense a deep puddle that exists for no more than 4 weeks can be considered an ecosystem, so can that birdbath that never gets drained, and unless the lake is completely sterile (which few are) the lake is an ecosystem.

It should also be noted that larger ecosystems are not necessarily more resiliant to change, in fact, I would argue that a complex ecosystem is likely to be more resilient, however there is much to know about the species and roles each plays before such a comment can be made.

I hope that helps.  Its a pretty simple answer to a question that is fairly complex if you want it to be.

Answer 2

Yes, Canada has many lakes due to glacial scouring during the ice ages. And yes, smaller lakes are more vulnerable to human activity or "natural" things like climate because they are smaller ecosystems. Larger ecosystems are more able to withstand disturbances, although any ecosystem can be disrupted. Hope this helps!