Tuesday, July 28, 2009

Poquanticut Cedar Swamp at Borderland State Park, North Easton, Mass.


The former Poquanticut Cedar Swamp, where Leach's Pond ends and Poquanticut Brook begins. The two humps of trees in the center of the photo, now islands in Leach's Pond, were once islands in a dense white cedar swamp, where a modest upward elevation change allowed white pines and oaks and maples to grow. "Islands in the swamp" such as these are common in the Hockomock Swamp, several miles to the south, and were marked and mapped and named by the 1700s.

After the Hockomock Swamp, the largest Atlantic white cedar swamp in Easton was Poquanticut Cedar Swamp, which is now underneath Leach's Pond in Borderland State Park at the Easton-Sharon line.

In his 1886 History of Easton, William L. Chaffin (who referred to Leach's Pond as Wilbur's Pond) writes:

"These two streams both flowed into the Poquanticut Cedar-Swamp, where Wilbur's Pond now is. They united in the swamp, the main outlet for the swamp being the same as the outlet for the pond, namely, Poquanticut Brook. The larger of the two branches that unite to form it is Poquanticut Brook, or River, the branch at the west."

In the 1820s, after the Poquanticut Cedar Swamp was clear-cut of all its trees, General Sheperd Leach mined the swamp for bog iron ore. After the bog iron was removed, a natural earthen berm on the south side of the swamp was raised to make a pond to provide water for mills in Furnace Village at New Pond on Foundry Street (Route 106).

According to Chaffin, the Poquanticut Cedar Swamp had two outlets, with Poquanticut Brook being the larger and more westerly. He describes a second brook that drained the swamp from the east:

"This small stream had its source in the swamp spoken of, before Wilbur's Pond was made. It was considerably larger once than now, because it helped drain the swamp ; but the dam checked the flow of water into it, and cut off its main supply. It still contrives to live, however, drawing from the swampy land through which it wends its sluggish way enough water to make a stream. It flows southerly, crossing Rockland Street between the Tarteus Buck and the Mrs. Horace Buck places."

This information tells us that Leach's Pond was most likely created by closing off the east outlet of the Poquanticut Cedar Swamp and building a small dam at its westerly outlet, Poquanticut Brook. The dam at the head of Poquanticut Brook no longer exists. Leach's Pond now spills naturally into the brook at a depth of just a few inches.


Poquanticut Brook as it begins at Leach's Pond.

Leach's Pond

Because it raised the water level of the Poquanticut Cedar Swamp by only a few feet, Leach's Pond has always been shallow, never more than 5-6 feet deep in most places. Today, the pond is rapidly reverting to an expansive wetland.

In just the past 40 years, from when I first went canoeing at the pond with my father and brother in the early 1970s, Leach's Pond has changed dramatically. At that time much of the pond was sufficiently free of water lilies to allow for easy fishing without constantly getting your lure or bait tangled, and thick weed growth was confined to the shallow coves and shoreline. Today, nearly the entire surface of the pond is carpeted with water lilies, pickerel weed and floating bog islands. This can be seen in contemporary aerial photos in which it is difficult to even recognize a pond.

A long, low east-west gravel berm which forms the south side of Leach's Pond and the walking trail along the pond suggests the berm is natural, glacially made feature, most likely a small moraine. Moraines are formed when the front of a glacier remains stationary for a period of time, causing the rocks and gravel locked in the ice to be all deposited in one position. This occurs when the melting rate of the glacier is equal to the forward speed of the glacier, meaning the glacier is still moving (in this case, to the south), but its front remains in one spot. By this piling of gravel, a long, low natural dam is created, often with a large, shallow pond behind it. As the pond slowly fills with rotted vegetation, it becomes a wetland and finally a wooded swamp. The Poquanticut Cedar Swamp was likely formed in this way. Once the cedar was clear-cut and the bog iron removed from around the cut stumps, Gen. Sheperd Leach needed only to block the eastern outlet brook of the swamp and increase the height of the natural berm by a small amount to create a 200 acre pond that exists at Borderland today.

Upper Leach's Pond

Upper Leach's Pond (or what my father called the "back pond") is a vastly different place than Leach's Pond and is unique in Easton. It is much smaller than Leach's Pond and follows a north-south axis with steep shorelines. There is a small wooden dam at the outlet of the pond, which is only 2 feet high, and its outlet stream flows for just a few yards into a cove at the northern end of Leach's Pond. The stones in the outlet stream are stained bright orange with bog iron and in the summer tiny hornpout can be seen in its pools.

Most notable about Upper Leach's Pond are the numerous floating islands that dot its surface; its depth -- which ranges from 5 to 15 feet; and its crystal clear water. These floating islands, which are natural gardens of pitcher plants, sundew, swamp azalea and other bog plants, reveal the pond's original character -- a quaking bog.

A northern pitcher plant on a floating peat island in Upper Leach's Pond.

A quaking bog is created when over thousands of years, layers sphagnum moss fill the entire bowl of a pond. Deep layers of sphagnum moss form what we call peat moss. Peat behaves like a kitchen sponge when it is saturated with water. If you press down on it, it easily gives, and water squirts out the sides, top and bottom. Imagine carving an enormous kitchen sponge so that it perfectly fits the bottom contours of a pond. Now try to walk across it. Like a sponge, the surface of the bog bends under your weight, water squirts out from the pressure of your feet, but you still can walk across it. Imagine a small tree growing on the top of the sponge, just above the water level. If you jump up and down on the "sponge," you can make a miniature earthquake and make the tree bounce up and down. If you can do this, you are standing in a quaking bog.

A pitcher plant growing in a floating garden of sphagnum moss in the middle of Upper Leach's Pond, Borderland State Park, North Easton, Mass.

Quaking bogs are not common because they require a very special set conditions to be created. Most quaking bogs in New England begin as glacial features called kettle holes. A kettle hole is made when a glacier is in its final stage of melting and retreating. During this melting process, enormous amounts of water and gravel flow out from the bottom of the remaining ice. As the melt water flows in various directions it often cuts off small blocks of glacial ice from the main body of the glacier. These blocks of ice (which can be hundreds of acres in size and 100 feet thick) become buried under many feet of gravel and stone. When these buried blocks of ice melt, they leave a water-filled depression in the ground. If this depression (the "kettle") intersects with the local water table it becomes a permanent pond. If the kettle only intersects with the local water table during the spring, it becomes a vernal pool, the birthplace of toads and salamanders. If the kettle is deep with steep sides, it will remain a pond for millennia. Henry Thoreau's Walden Pond in Concord is a classic kettle hole pond, as are most of the deep, spring fed trout ponds on Cape Cod, like Hamblin's Pond, Schubael's Pond, Deep Pond, Spectacle Pond, Peters Pond, Mare's Pond and Big and Little Cliff Pond way down in Nickerson State Park in Brewster.

Upper Leach's Pond does not have the classic form of a kettle hole pond: which are roughly circular and have no inlets or outlets. However, its features suggest that like a kettle hole, it began as a glacially scoured depression filled with ice, which then melted, leaving a pond of medium depth that has been slowing filling in more many many centuries. So exactly how do we describe a very unique place like Upper Leach's Pond? This requires detective work.

A swamp azalea (Rhododendron viscosum) growing on an island of floating peat in Upper Leach's Pond, Borderland State Park, North Easton, Mass.

First, we note that Upper Leach's Pond is quite deep for a small pond. In most places, aside from the floating islands of peat and surface plants, the pond is 10 to 15 feet deep. Next we note that the dam at its outlet, a stack of three 8 x 8 boards, is only 24 inches high. If these three boards were removed, the pond would only drop in elevation by two feet, still leaving a fairly deep pond.

I have no idea what this flower is, except that it is growing out of the water at a floating peat island at Upper Leach's Pond. Note the white insect egg cases on its stem.

Third, we note the abundance of pitcher plants and sundews on the floating mats of peat that dot Upper Leach's Pond. Pitcher plants and sundews are quite unique in that they trap and eat insects. Pitcher plants do this by folding their leaves into a tall cylinder with a trumpet shaped bonnet that allows rainwater to collect inside. Thousands of fine hairs coat the inside of the trumpet, all pointing downward. Insects, especially ants, that explore the interior of the trumpet fall down into the tube and into the pool of rainwater at the bottom. The downward pointing hairs make it difficult for insects to crawl back out. Once trapped at the pool in the bottom, the insects drown and are dissolved and digested by the pitcher plant.

A pitcher plant at Upper Leach's Pond, showing the fine hairs pointing downwards that keep bugs from crawling out of its maw.

Sundews are much smaller than pitcher plants and capture insects by a very different method. The stems of a sundew end in a fleshy pad that looks like a canoe paddle. Each paddle is studded with tiny stems so that it looks like a pin cushion. The end of each pin is covered with a drop of sticky, glistening liquid. When an insect lands on the pin cushion, they become stuck in the drops of sticky liquid and many cannot escape. Once an insect is trapped, the sundew slowly wraps these pins around the insect and eats it.

A sundew on the edge of a floating peat island in Upper Leach's Pond, Borderland State Park, North Easton, Mass.

Pitcher plants and sundews evolved the ability to attract and eat insects because they live in wetlands that lack key minerals they need to live. While most plants obtain these minerals from the soil, pitcher plants and sundews basically live in water, and more particularly, water that lacks these minerals. To make up for this deficit, pitcher plants and sundews obtain these minerals by catching and eating insects. Ponds and swamps that are fed by perennial brooks contain enough minerals in their water to give plants all they need. Only in special cases, like a kettle hole bog fed only by rain and snow and groundwater, do pitcher plants and sundew have the advantage over other aquatic plants due to their ability to catch insects and extract their food directly from them.

A sundew next to a water lily about to bloom on a floating peat island in Upper Leach's Pond, Borderland State Park, North Easton, Mass.

An important feature of Upper Leach's Pond is its inaccessibility. When I first went there, in the early 1970s, the entire area was still owned by the Ames family. One Saturday morning, my father put our canoe in the truck and we drove up Lincoln Street to Bay Road and down the unmarked dirt road to the white farm house next to Leach's Pond, in what is now Borderland State Park.

We put the canoe in at the east end of Leachs' Pond and as the morning went on and the sun rose higher we made our way to the northwestern end of Leach's Pond. Upon entering a small weedy cove, we pulled the canoe out and dragged it over a gravel berm and entered the "back pond," Upper Leach's Pond. Once in the back pond, from my seven year old eyes, we entered a different world.

The pond was much deeper than Leach's Pond, where your canoe paddle would often touch the bottom. And it was full of strange, floating islands and mats of vegetation that suddenly dropped off to the bottom, which we could not see. The water was crystal clear, and when the sun was at the right angle (it was noon by this time), you could see "caves" beneath the floating mats of peat and, sometimes, if you cast your Jitterbug just right and didn't hook the island, a 2 pound bass would come out from a cave and suck in your Jitterbug with a resounding thwop.

Because we were in a canoe, we could paddle right up to the mats in the middle of the pond and look at the scarlet and green pitcher plants growing at their edges, and my father explained what they were and how they caught bugs. When we went home that afternoon, as the sun went down, I felt as if I had been briefly dropped by spaceship into a weird world where some things were familiar, like bass and pickerel and lily pads and water, but much of it, like floating islands covered with odd looking plants that ate bugs, were nothing like I had ever seen before.

To get the photos of seen here, I brought my underwater digital camera and swam out to one of the larger floating islands and precariously pulled myself on top of it and then walked around as if I was its proud, albeit, temporary, owner. This is something I have wanted to do since I was 7.

Puds Pond

Puds Pond is due east of Upper Leach's Pond, and the two lie almost parallel to each other like tiny finger lakes, separated by a small neck of high ground extending south from Mountain Road. Puds Pond is created by a 12-15 foot high poured concrete dam, which due it its design and materials, appears to have been erected in the early 20th century by the Ames family. Chaffin makes no mention of Puds Pond in his 1886 History of Easton, which suggests the pond and dam did not exist when he wrote his book.

Unlike Leach's Pond, Puds Pond is deep, at 12-15 feet at the concrete dam. Unlike Upper Leach's Pond, it has no floating islands of peat, and based upon the height of the dam at its outlet, it was never a natural pond. What is now Puds Pond was until the early 20th century a small, clear, fast-flowing brook that shrank to a near trickle during the summer. This can be deduced by measuring the height of the dam and the length of the pond. The height of the Puds Pond dam is about 12-15 feet and the length of the pond created by the dam is about one half mile. This can be seen at the pond's inlet at Mountain Road, where it is a small wetland with a surface just a few feet below the road bed. This tells us that in the half mile distance from Mountain Road to the 12-15 foot high dam at the outlet of Puds Pond, the brook dropped 12-15 feet in one half mile. That is a gradient of 24-30 feet per mile, which is a very fast moving stream, perhaps one of the fastest in Easton. The road at the top of Puds Pond was not called Mountain Road for nothing.

Puds Pond is the best swimming spot in all of Easton. The water is amazingly clear (you can see bottom down to 20 feet) and there is a perfect area of sand and gravel for wading at the small beach just to the right of the dam. Before Puds Pond was made part of Borderland State Park, this little beach was very popular with Easton residents, especially teenagers, because you could drive to the pond from the dirt road at the intersection of Bay Road and Allen Road, or by walking in from Mountain Road. Unfortunately, these same teenagers and young adults had a habit of trashing the area with beer cans, McDonald's wrappers, broken bottles and breaking off every nearby living tree to make bonfires. This turned an incredibly scenic and enjoyable spot into an unsightly and dangerous dump. Today, you have to walk into Puds Pond from Bay Road or by a very long walk from Massapoag Ave. and the swimming area has a goofy "no swimming except for pets" sign posted on a tree. Feel free to ignore the sign and go swimming anyways. It's your pond.

UPDATE: Since writing the above I have examined aerial Ektrachrome slides taken by my father, Allan E. Watts, of Borderland State Park during the fall of 1970. From these photos it is fairly obvious that Upper Leach's Pond was naturally a part of the lower pond, and presumably during the early 20th century the Ames family had constructed a low berm and trail to connect the west side of Borderland to Puds Pond and in doing so made a dividing barrier which created what we now see as Upper and Lower Leach's Pond. As best as I can surmise, what we now call Upper Leach's Pond was "scooped out" much more by glacial action than Lower Leach's Pond which would explain its much greater depth.

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