Vernal ponds are temporary wetlands that fill after the snowfall each spring. This fact sheet focuses on geological influences and recognition.
Have you ever walked through the woods in spring and found an immense puddle that wasn’t there over the winter? you may have discovered one of the most ecologically important habitats to be found among Michigan’s woodlands.
The are other Earthcache nearby focused on Vernal Ponds. GC1XE70 and GC257Z6. These are great examples showing the ecological aspects of Vernal Ponds.
Where You are.
However this vernal pond differs from those because it is not only filled by rains and snowmelt but also filled when the rivers near the pond overflow during heavy rains. Most years the pond will mostly dry out in the summer months. The rains of 2014 were very heavy and the pond did not dry out that year. The Vernal Pond is situated where the Red Run and Plum Rivers converge. A short way north, you will be able to see a second confluence where the Red Run converges with the Clinton River.
Confluence of rivers is defined as a meeting point of two or more rivers. In other words it usually refers to the point where a tributary joins a major river, called the mainstream. In general, downstream of the confluence, the river having the combined flow of rivers/streams is known as the main stream, but in some cases a new name is also given to the river after the meeting of two streams/rivers.
The Plum River is a natural river. However the Red Run , once a small river not much more than a creek; has changed over the last 200 years. Population growth has greatly changed the river as man made runoffs were diverted into it. This would included runoff drains from roads and overflow of collection basins in new subdivisions. The Red Run originates west of the intersection at 13 mile and Woodward in Royal Oak and runs just north of this confluence where it merges the Clinton River. This system diverts many times more water to this spot than it would have years ago.
Every 2 to 5 years this area experiences severe flooding. With a short walk to N 42 34.058 W 082 58.247 you will see a confluence of the Plum River ( flowing West to East) and the Red Run Drain (flowing South to North). Looking to the North about 100 yards you will see that this water again merges with another river, the Clinton River. All this is part of the Clinton River Watershed. ( question 1 - Looking at leaves or sticks in the river you can see which river runs faster?)
Go to N 42 34.049 W 082 58.274. From this ridge you can see the geological makeup that supports the vernal pond. Notice the elongated depression to your West, running North/South. As the snow melts in spring and the rains start, the runoff leads to the pond to your South. Although not a large area, everything flows to the depression and narrows as it heads to the river. You can also see the effects of the receding waters after a flood. Notice how the dead branches and other foliage collect here.
In the summer of 2014 there was the worst flooding this area had seen in over 50 years. If you look south at Metro Parkway; take note of the bridge. During this flood it was completely submerged in flood water. This will give you an idea of how bad the floods were. Though you are on high ground, this was under water. Many local rivers and lakes were still higher than normal, 4 months later. In the 6 years I have hiked this area and have never seen this vernal pond hold so much water so late into November.
Go to N 42 34.064 W 082 58.277. You will see a small trench coming from the south. This is where there venal ponds drains to the river and naturally controlling the depths of it. When the river floods and first crest the banks of the river this is the first area that water backfills to the Vernal pond. (question 2 - Take a elevation reading as deep in the trench as possible. Then look at the river and gage how much the river would have to rise and flow back to the pond).
Now lets go to the Vernal Pond at N42 34.023 W082 34 58.299.
What To Look For
It’s easy to recognize vernal ponds in the late winter and early spring. Named from vernalis, the Latin word for spring, vernal ponds are formed seasonally in shallow ground depressions from spring snowmelt, precipitation, and rising water tables. Generally drying up in late summer, these ponds are only temporary woodland reservoirs. They are slightly harder to identify during the summer and fall months; however, there are several clues to look for. Blackened, compressed leaf litter; gray soil; watermarks on surrounding tree trunks; and the presence of moisture-tolerant vegetation all suggest an area that collects water part of the year.
Vernal ponds themselves are generally less than 40 yards in diameter and no more than 4 feet deep, although they receive water from a larger surrounding landscape. Much of the topography that makes Michigan’s vernal ponds possible was first formed during the last glacial period and is the result of 10,000 years of irreplaceable geologic history.
Vernal ponds are temporary wetlands that fill after the snowfall each spring. They become the seasonal breeding and feeding grounds for many intriguing amphibians and insects, as well as the reptiles, birds, and mammals that depend on them for food. you may have been led to this pond by the unmistakable sounds of frogs calling for a mate.
Left to right: Late winter and early spring vernal ponds are filled with water. Vernal ponds begin to dry up in summer; some are completely dry by late summer.
Ecological Importance
If a vernal pond’s physical features don’t tip you off, the wildlife living there will certainly give away its location. Vernal ponds are home for a diversity of animals that count on them for the spring breeding season.
The seasonal nature of vernal ponds means that they are uninhabited by fish. This makes them the perfect habitat for a variety of amphibians and invertebrates to breed and develop with less chance of predation. Species like mole salamanders, wood frogs, and fairy shrimp depend exclusively on vernal ponds for this part of their life cycles. Often a pond is the ancestral home of an amphibian community that resides nearby in the forest each winter, then migrates to the same pond each spring to lay its eggs.
Many species use vernal ponds in spring. American toads, gray tree frogs and green frogs are among the many other creatures that may come to breed.
To claim this Earthcache as a find you will have to e-mail the owner the answers to these questions before logging the cache.
1) Which river is faster Plum or Red Run?
2) N 42 34.064 W 082 58.277 Take a elevation reading as deep in the trench as possible. Then look at the river and gage how much the river would have to rise and flow back to the pond.
3) Provide the elevation readings at the edge of the vernal pond(If it is dry find the lowest point), at N42 34.023 W082 58.299. Provide and compare to the elevation level at the point where the trench dumps into Plum River. N 42 34.064 W 082 58.277.
4. Use your GPSr and take readings at the widest point of the Vernal Pond. How wide is the water at its widest point? How deep do you estimate the water to be? Is the Vernal Pond dry?