CP:TNG (Cottonwood Pond: The Next Generation)

CP:TNG

(Cottonwood Pond: The Next Generation)

Late October 2017

October 29

When I started this blog several years ago, I had gone where no woman or man had gone before … down to the bottom of my woods to see what was going on after a large Cottonwood had fallen down.

As the tree fell (the top lodging in the “v” of a two-trunk Red Oak tree at the top of the back slope), it created a significant change in the bottom land that would influence the way water moved, the way plants grew, and what animals would exist down there, if even for a brief time.

Even a deep footprint left in a soggy spot will change the way things respond and function in and around it. It creates a place for water to collect and, when dry, for seeds and spores to accumulate. It makes a new spot for tiny critters to explore and perhaps to find food or burrow more easily into the ground.

Imagine the difference when the expansive root system of a large Cottonwood pulls from the ground, taking with it almost all of the soil that had supported it. Imagine the difference between that huge bowl left in the earth and a sunken footprint.

That's what I wanted to explore. This was in the bottom, where water gathers and the Creek flows past.

The front slope of the home woods, with the bottom land below

Creek bed going through bottom land, as seen from Barkless Log near Cottonwood Pond 

And this was in a place of silty soil that holds water like an unfired clay pot. So, when the great tree fell it created a large pot, so to speak, that collected and held water. The only time it did not hold water was during extended dry periods, when the existing water would evaporate and there was no precipitation, melt, or drainage replenishing it. Was it a vernal pool, which fills with water (and snow and ice) during the winter and the spring rains, drying up when the hot summer sets in? That is uncertain, as the bowl would hold water anytime during the year there was ample rain. During dry periods, it was not overtaken by opportunistic plant life, as often happens in a vernal pool (though there were sometimes a few plants.)

Looking southeast across Cottonwood Pond: Root Ball and Mud Pile on left, Barkless Log/Inlet at far end

One of my objectives was to observe that bowl of water. I wanted to see how it might encourage, invite and support various forms of life, and how it would change and develop.

As it turned out, Cottonwood Pond, as I came to call it (using the word “pond” loosely,) went through so many significant changes – some I predicted or could have easily predicted, and some that surprised me. I have watched not only the “pond” transform but the fallen tree and the whole area around it. I watched the tree's influence on everything. And that's what it became: The tree itself, though gone by, has been the largest factor. Whatever happens to the tree happens to everything. Lately I have found my focus changing from primarily the bowl to primarily the old Cottonwood itself.

Looking northwest across Cottonwood Pond: Barkless Log/Inlet in foreground, Broken Blue Beech above, Root Ball and Mud Pile on right, the bowl in the middle

The “pond” fills in. It is eroded by the push of water pouring in. It changes shape by that force, and also by the piling-up of sediment falling from the roots. The tree has changed the direction of water flow around it, into the bowl, and it has changed the depth and width of the bowl.

Where water once seeped across the bottom land after flowing down the slopes and overflowing the Creek bed, it has been funneled and redirected by the presence of the horizontal tree, its giant root system and the bowl it created.

The bowl, its water, and the life that anchors in it become food and foundations for other forms of life. This has been true not just in the main bowl, but in all low areas around the now vertical root system. This has included the smaller low spot below the top side of the Root Ball, which I have called “little pond.” It has also included the Swampy Spot that developed to the southeast of the Trunk, the flow of water that goes to and collects around the Inlet to the pond (under the Barkless Log that stretches over) and the Seep, where overflow from the pond travels to the Creek. It also has included the spread of water that moves from the overflow of “little pond,” eventually entering the Creek further upstream.

Now I feel it is time to look to The Next Generation of the tree, the pond, and everything around them. What I have seen lately is a tipping point. It is all quickly on its way to becoming something else. What will be this “something else?” The following are my speculations:

Over time, soil has fallen from the Root Ball to the bowl below (much less so on the top side.) At first this created Mud Piles, then one big Mud Pile all along the bottom. The dropping of soil seems to have seen exponential growth, as if once it got going, it really got into it. This has been encouraged by rain, freezing and thawing, and by extended dryness.

The Bowl

Lately, there has been a massive dropping of soil, reaching into the middle of the bowl. The shape of the part that can still hold water has become narrower, like a crescent moon thinning during its waning phase. There has been enough rain during the autumn for water to collect, but not consistently enough for water to build depth and remain, as it used to. So, it has been difficult to see how the new shape would affect drainage, and it if would still be able to support some of the life that it has in the past. Also, the piling of fallen autumn leaves on the pond bottom every year adds to the soil as it rots throughout the winter and spring.

My speculation: As there is still soil in the old root system, there is much more to drop and to continue filling the bowl. Gravity has been taking it further into the middle. When we do have enough rain (and melt,) the moisture will not only knock down more soil, but moisten what has dropped and push it out further. Before long, the bowl will be filled with soil, enough to prevent a pond-like filling. It will be interesting though, to see if an extended force of water through the Inlet would keep carving a deeper channel across the bowl.

The Very Rotten Log

The top end of the Very Rotten Log, which stretched across part of the pond and through the Inlet, eventually rotted enough to lose a section to the middle of the pond. While that piece is gradually becoming part of the pond bottom, the remaining end has been supporting a nice colony of moss and some seedling plants. Meanwhile, the bottom end of the Very Rotten Log, which spans the Creek, has become wet as a sponge whenever it rains, crumbling more quickly, and supporting moss, lichen, mushrooms and some seedlings.

Bottom end of Very Rotten Log spanning the Creek

Fungus and moss on the Very Rotten Log, over the Creek

Shelf fungus on Very Rotten Log, over the Creek

My speculation: It takes no real speculation to know that the whole Very Rotten Log will disappear into the ground, the Creek and the pond bottom.

The Old Cottonwood Roots

As time goes on, the roots and rootlets of the old Cottonwood have been doing what any old, rotting wood does – breaking up and falling apart. Sometimes birds and other animals help break them down, drilling into them. Chunks of roots fall to the bowl below.

Exposed roots excavated by various birds and small animals, on Root Ball Top and Bottom

My speculation: They will likely be covered with dirt sometime, and also rot into the soil of the bottom, becoming part of that soil.

The Root Ball

Animals have burrowed into the dirt of the Root Ball increasingly over time, perhaps because the thinning of the Root Ball and the increased exposure of the old roots creates more spaces. Their burrowing helps loosen the soil and destabilize the old root system.

My speculation: As roots break and fall, as animals burrow, and as more dirt falls, the base of the old Cottonwood tree becoming thinner and less stable, it will someday disappear into the soil below.

Soil clods and pieces of root fallen onto the pond surface from the Root Ball

The changing Root Ball has also invited a parade of life to use it as a substrate, and a place to hang on and dig in. Besides the burrowing animals, spiders have built webs stretching across from exposed root to exposed root, and sometimes across burrow entrances. Lichen, fungi and mosses have found surfaces and niches to grow and prosper. These, though, while deriving nutrients from the wood and soil, also help to break it down.

The Saplings

The most outstanding change at the Root Ball, the factor affecting it the most, has been the growth of numerous tree saplings. The first were the White Ash and Sugar Maple seedlings that sprouted from the top edge and quickly great, creating their own little canopy above Cottonwood Pond. The saplings invite birds to visit, and even, as I once saw, snakes to twine around them. Caterpillars and other critters dine on the leaves. Birds resting in the saplings may drop seeds from berries they collected elsewhere, which can take root here.

Sugar Maple and White Ash saplings on the top edge of the Root Ball

Next, new Blue Beech saplings sprouted from the base of the Cottonwood Trunk and developed very odd growth. One limb-to-be stretches along the Trunk, while two more point upwards. I am not sure if these originated from the old Blue Beech that grows from near the pond edge (originally the Bent Blue Beech that bends over the pond to the Root Ball and beyond) or if they sprouted from seed. I am wondering if one of these future limbs will win out over the others, or if this will become one very weird Blue Beech.

Looking up the Trunk and the horizontal part of the Blue Beech sapling

The developing canopy of the two vertical Blue Beech saplings.

There are also tree saplings (more Blue Beech, and other types) that have been sprouting from the top side of the Root Ball. They have gained in growth exponentially, curving upwards at their bases from their vertical source.

Root Ball Top and Cottonwood Trunk with "little pond" below (see Blue Beech saplings growing from Trunk base, and saplings growing out of Root Ball Top)

Developing canopy of saplings growing out from Root Ball Top

The Bent Blue Beech became the Broken Blue Beech when it cracked and then snapped in the middle of its bend, directly over the pond. Those sections are now riddled with insect holes and shelf-type mushrooms. The two sections have moved farther from each other. The one connected to the original tree has moved upwards, while the one embedded in the Root Ball has moved down. As the original Blue Beech died and has continued to deteriorate, many saplings have sprouted from the base and have been flourishing, gradually creating their own new canopy.

There are also saplings that have sprouted alongside the pond, the Trunk, and all around, and they, too, have been rapidly growing. One example is the Boxelder next to the Trunk. I may have aided it when I removed and Asian Bush Honeysuckle nearby. Another example: The many Elderberry shrub saplings that have grown very tall and produced large heads of flowers and fruit, feeding birds.

Young Boxelder tree next to Cottonwood Trunk

My speculation: The saplings, all of them, are the most obvious Next Generation (see “Overall Speculation.”)

The Old Cottonwood Trunk

After the Cottonwood fell, it was still covered in its rough bark, but soon sections of the bark began coming loose and falling off. Eventually, the only bark left was near the base of the Trunk, leaving the rest of the Trunk smooth and grayish all the way up. Fallen bark began to add to the soil below, or was washed by heavy rain into “little pond,” stifling water flow there like a small dam, or changing its course. Seeds and spores lodged into crevasses next to bark pieces remaining on the Trunk. From those tiny spots would grow mosses, lichens and seedlings, and also mushrooms of various kinds.

Moss and fallen leaves on the remaining bark of the Trunk

Soil developing on the Trunk

Little mushrooms developing on the bark of the Trunk base

Bits of soil were created there. Cracks in the bald parts of the Trunk sometimes sported fantastic-looking mushrooms like Oysters, which were also dramatic when shriveled.  The old dead Trunk was filling with fungi mycelium, which was feeding from the wood and helping to break it down.  Further up the slope, and old Black Cherry tree had cracked and fallen in a storm, its trunk and branches landing on the Cottonwood Trunk. And, of course, there were those aforementioned Blue Beech saplings growing from the Cottonwood base.

My speculation: The Trunk will be the most obvious contributor to The Next Generation (see “Overall Speculation.”)

The Barkless Log and The Inlet

Some time ago, a tree just to the south of the Cottonwood fell across the bottom and the Creek and alongside the Cottonwood.  I’m pretty sure, but not positive, that it was a Sugar Maple. I called it the Barkless Log because it was devoid of bark by the time I was studying the area. It became the southeast border of the main pond after the Cottonwood fell and left the large bowl.

With rains, water coming from downslope momentum began eroding a couple of small spaces under the Barkless Log, to reach the pond. Eventually the whole section under the Barkless Log was eroded into a complete open space where water could pour in. I have always referred to this as the Inlet because it has been the main location of water input to the pond. Water coming through the Inlet also brought a great deal of sediment, added to the pond bottom or pushed further, depending on the strength of the rush.

Outside the Inlet

The Barkless Log has recently shown signs of greater deterioration. It also sports mosses, lichens and seedlings, and interesting mushrooms, including a vivid purple jelly fungus. Ants and other creatures have been frequently seen moving about on the Barkless Log.

(actually deeper purple than this)

Jelly fungus and White Ash seeds - generations

Where the Barkless Log meets the southeastern edge of the Root Ball, it divides into an upper and lower limb. The lower, close to the constantly wet ground and near the Swampy Spot, has been rotting more quickly, aided by animals that gouge at the soft wood, looking for food. However, this has been happening on the upper limb, too.

My speculation: Though it will take much longer to rot than The Very Rotten Log, The Barkless Log will eventually rot enough to drop into the space called The Inlet, impeding an important water source for the pond. As the Barkless Log rots down to a flat surface of mostly soil, water may rush over it. Of course, the Barkless Log will be feeding the saplings, other plants, and related critters around it.

The Cove, the Isthmus, the Seep and the Swampy Spot

The Cove is the space at the bottom of the Root Ball that eventually became large enough for water, and frogs, to pass through between the main and “little pond.” The increasing Mud Pile has been gradually blocking the Cove.

The Cove 

The Isthmus is a narrow place at the north edge of the Root Ball where water passes between the main and “little pond” during heavy flow times. The Seep is an over-flow path from the northwest corner of the main pond to the Creek. The Swampy Spot is to the east/southeast of Cottonwood Pond. Water flows down slopes, gathering at the bottom, and then becomes Temporary Creek #1, which empties into the Swampy Spot. Over-flow from the Swampy Spot trickles under the Trunk to “little pond,” as well as along a flow path to the Inlet and main pond.

My speculation: All of these have been changing shape and depth with changing dynamics. See “Overall Speculation.”

Overall Speculation:

What will it all become? What is the future of this place I call Cottonwood Pond?? What will constitute The Next Generation?

That can be hard to say, as there have been some significant events that have surprised me, and I expect there will be more. But I can speculate and theorize.

I speculate that the whole area will become filled-in, yet will be a low spot in the bottom where water will still tend to accumulate, overflowing when the rains or melts are strong. I have watched the area from the time there was a distinctly larger “pond” in front of the Root Ball Bottom and a distinctly smaller “little pond” below the top side – very separate from one another. I have watched as the area has become re-sculpted and sometimes inundated so that there was no distinguishing between two bodies of water. I predict that this will become gradually more indistinguishable, leading to one large swampy area. There will be no Isthmus. It could connect with the Swampy Spot, eventually. But, before then, such an event will be prevented by the Swampy Spot being blocked from the rest of the area by dropped, rotted logs. All of the Barkless Log, including the upper limb, will be on the ground. And as the Trunk further deteriorates, it will also drop closer to the ground. A large section held over the ground near “little pond” may eventually give way to gravity and break, landing on the ground. This will cause it to rot more quickly, also.

There will still be Temporary Creek #1 (feeding into the area) as well as Temporary Creek #2 and the Seep, both as overflow paths to the Creek.

As the Barkless Log drops to the ground, water will no longer be able to sculpt a path in the main pond, at least not for a long time. This will allow the pond to completely fill through soil dropping from the Root Ball and soil-building leaf and wood accumulation, and perhaps even from plants that may take root and die there in ever greater numbers. This means that it will no longer support some of the pool/pond wildlife that it has in the past, especially tadpoles-to-frogs. There is a possibility that the whole area will be one big inundated bowl of water during wet times that may support such wildlife, maybe even more so than when there were two separate, small pools.

The Root Ball will become bare of soil. It will further thin from deteriorating roots constantly breaking off and falling to the soil below. Eventually, far in the future, the root ball and Trunk – the whole old, fallen Cottonwood tree - will disappear into the wet ground, feeding The Next Generation.

And that Next Generation will be mainly all of those saplings – the numerous Blue Beech ones sprouted from the Bent (Broken) Blue Beech base (by the way, it won’t be long before the sections of Broken Blue Beech fall to the ground,) the odd Blue Beech triad growing from the Cottonwood base, the saplings growing from the Root Ball Top side and the top edge of the Root Ball, and all of the tree and shrub saplings growing very near in the vicinity (Elderberry, Boxelder, and many others.) Those growing on the Root Ball will have been sending their roots to the ground below, finding more anchorage there, and soil will build up around them as the Root Ball rots away.

The Next Generation will be that collection of various trees and shrubs down there that I have watched grow from little seedlings and quickly gain strength, width, height and canopy. There will hardly be any sign of the old Cottonwood, the Very Rotten Log and the Barkless Log that will have been feeding them, giving way to them. For those new moisture-loving woodies, this will be their world, their universe, their time, and all wildlife in the area will adapt accordingly.

Dead tree near Cottonwood Pond, possibly home to Woodpeckers - it will fall someday and become part of the regeneration of the area

Even if Cottonwood “Pond” soon disappears, I will continue to study this area. I thought I would be studying the formation of a pond (or pool) and how it develops over time as a pond. Instead, I am studying the life and giving-way of that pond, and how that ecosystem changes of which it is a part.

It is an adventure of exploration and discovery – into the unknown. I will boldly go forth, continuing this adventure.