For March’s photo of the month, we bring you this wonderful shot of Minnekhada Regional Park, taken by Flickr member Dru! Taken on New Years Day, Dru! clearly wasted no time sleeping that day and instead trekked out into the winter weather to explore his local wetlands. The photo stuck out to us at the Wetlands Education Program, due to its subtle beauty and composition. The grey tones of the image generate the feeling of a cold, surreal landscape; in summary, what we in Metro Vancouver experience on a daily basis for 8 months of the year! The contrast of the green trees against the grey shades, however, are what make this photo exemplary.
By looking at this photo, we can learn a lot about wetlands and how they function. While a keen eye may spot the beaver lodge on the water (near the left side of the image), of interest to us are the thick, looming clouds overhead. These clouds – while we may dislike them as they seem to always been present in the Lower Mainland – are critical to wetlands and the hydrologic cycle.
Hydrologic Cycle – Source: National Weather Service. http://www.srh.noaa.gov/jetstream/atmos/hydro.htm
In the above image, we have a simple diagram of how the hydrologic cycle functions. Using our imaginations, we can superimpose this diagram on the photo of Minnekhada Regional Park. The mountains (overlooking the wetland) cause the rising air to cool, thus triggering condensation (via a process called adiabatic expansion). Such condensation forms the thick clouds that accumulate against the mountains, a feature we are used to seeing in Metro Vancouver. As the moisture in the air joins through coalescence, larger droplets are formed and eventually precipitate in the form of rain. The resulting surface runoff eventually feeds into the wetland, where its energy is dissipated upon contact and its suspended sediments (and contaminants) are filtered. The water that enters the wetland is eventually removed via: (1) evaporation; (2) outflow into a connecting stream or tributary, or by (3) slow release through the ground (that will eventually feed into groundwater or a connecting stream). Regardless of its exit, its ultimate fate is always the same: eventual evaporation into the air to continue the hydrologic cycle (and make more clouds)!
With this knowledge, and the effort of Dru! by taking this photo, it is easy to understand the role wetlands play in both the hydrologic cycle and nature. In essence, they act as giant “sponges” that take in incoming water and slowly release it into the environment, thus providing flood control measures. In addition, many wetlands possess biofilters, hydrophytes, and organisms that are capable of breaking down toxins and contaminants in the water. This filtration process is critical to maintaining water quality in the surrounding regions.
Thanks go out to Flickr member Dru! for taking this shot and contributing to wetland conservation efforts! Stay tuned for April’s Photo of the Month…