Removing Invasives in Deep Snow

The bones of the forest in the winter landscape

Now is a great time to get outside and tromp through the deep snow and remove Multi-flora Rose.  The snow is starting to lose its charm. We have been finding more and more native trees and shrubs in Morris Park  that have broken and split under the weight of the snow.

Its an ongoing inventory of destruction. A whole plant splits at the trunk. What to do? Prune it?

Do nothing is the conclusion and here is why:  The bark remains intact, and there is a whole network of buds ready to go to leaf and photosynthesize in the coming season. Even with the split trunk, the plant will still go to leaf and subsist. The energy created by this process will help the plant rebuild its structure. Once this process has been established and new growth commences as the season progresses, the plant will abandon the damaged section, which will die and rot off eventually.  We examined many spicebushes (Lindera benzoin) today and could read the history of each plant by looking at the branches.

Every specimen tells its own story, and when analyzed as a group, simple conclusions can be ascertained: Branches of this shrub are being split every winter.  These branches continue to live, but only for one season.  They then die, and turn red. The plant sends up robust new shoots. Eventually the dead branch falls off, and the trunk heals the scar. Sometimes the plant does just die. Most of the time it continues to live, regrowing what has been lost.

Winter is a great time for this study and reflection of the bones of  the trees and shrubs.

Multiflora Rose, a difficult exotic invasive, has created impenetrable thickets throughout  Morris Park, crowding out native plants, and reducing the productivity of the natural ecosystem.  This plant has sharp thorns that easily penetrate clothing, making it difficult to remove.  However, in the winter, this plant is dormant and more easily accessed.

With thick winter clothing and work gloves, we are able to move right into the thickets and cut down the descending canes enough to access the ascending sections of this arcing menace.  We leave the rooted stub in place until the snow melts and the soil is wet and friable, so we can easily pull out the entire plant for disposal.  Removal of the roots is essential for the effective control of this plant. The roots are considered propagules, which are any part of a plant that can reproduce into a new plant.

A mass of invasives

In the immediate foreground is a spicebush that was covered with invasive vines last May, until we removed them. It survived this snow event very well. However, much of its bark was rubbed off by deer rubbing their antlers, called “buck rub” and now the bush is at risk of death. The arched figure in the back-round is a Black Cherry pulled down by a mass of grape vines and the weight of the snow. Today we removed all of the vines threatening this tree, which began to perk up, rising from its prone state.

The snow is so deep that it is hard to move, so we had to stay in one spot while we worked.  We still were able to begin the abatement of  a thicket of Multiflora Rose (Rosa multiflora),  and a stand of Burning Bush (Euonynmus alatus).  Our feet were cold at the end of the afternoon, but  we were able to be outside for the duration of this winter day.

Saving Spicebushes from Breaking under Weight of Vines and Heavy Snow

Walking Keeba in Morris Park
Walking Keeba this Morning In Morris Park

Walking the dog this morning, we noted how many small trees and shrubs in Morris Park were leaning heavily or were broken. These were only in the unrestored areas that have lots of vines covering them.  In all of the areas we had worked on removing the invasive vines, the trees and shrubs were doing fine in this heavy snow. Pointing to a Tulip Poplar (Liriodendron tulipifera) that had broken in half under the weight, Sean said “if only we got to that one, it would’ve taken only a few minutes to remove those vines.  Now its ruined.”

Tulip Poplar broken in half

With large areas of the forest without tall trees, there is concern about the future of the forest canopy in the area of Morris Park we are focusing on. When the large trees are dying off one by one, and there are few mid-sized trees, a whole species of tree is blighted so badly that it never reaches even near maturity, and the small trees are under assault from the invasive vines, we wonder what it will take to bring this under control.

We have seen other areas of the park that are further advanced in this process of environmental degradation. It was difficult to even access these areas, because the invasives were so prevalant, they created an impenetrable wall.  We did manage to see them however, and it is not a pretty sight. No tall trees at all. The only trees were Ailanthus Altissima, the tree of heaven, covered in either  the invasive exotics Multiflora rose(Rosa multiflora) or Japanese honeysuckle (Lonicera japonica). Mile-a-minute vine covers the dead tree trunks of the former forest.  These areas do not look like a woodland at all. There are no herbaceaous plants on the forest floor . Everything is a dense thicket of invasive vines.

The area that we are concerned with is on its way to this final stage of forest destruction.There was this one area of Spicebush (Lindera benzoin) that looked especially at risk this morning.  The shrubs were buried in the snow.

Spicebush verging on breaking under the weight
Spicebush nears breakage from invasive vines and snow weight.

However, with 15 inches of heavy wet snow outside, the idea of going into the Park and off the trail (Which is used enough that the snow is compacted) was a bit daunting.  However, cabin fever can be problematic, and it was worth a go to at least try to do something.

Properly dressed with insulated work gloves, a ratty old coat that can take a beating, work commenced here:

Morris Park, near the terminus of Morris Park Road

Not  a bad spot to spend the afternoon in.  Looking down, however is the work:

The trees are bent down under the weight-'before' picture

Here is  Spicebush and an unidentified tree about ready to break.  This is a combination of  vines and snow. Having just sharpened  the pruners with a file and a knife sharpener and with a drop of oil for smooth operation, the work began, cutting off the vines that were strangling these two trees.  The vines were Grape (Vitis spp.) Japanese Honeysuckle (Lonicera japonica), Oriental Bittersweet, (Celastrus orbiculatus) and Multiflora Rose (Rosa Multiflora).  In just a few minutes time it looked like this:

After removing the vines, the trees sprung back up :'after' picture

Then there was this one Spicebush buried in the snow. While it took an hour to dig out the car , this Spicebush was dug out of the snow and liberated in ten minutes:

The Spicebush, in lower part of the picture, buried in the snow

This, above, is the “before” picture.

The liberated Spicebush The "after" picture

This is the “after” picture. (date incorrect)  The Spicebush just rose up from the snow and ice as the vines were cut away. It was very satisfying to watch the shrub spring back up to a vineless, healthy future.

This area, next to the Spicebushes rescued today, awaits restoration

Hopefully tomorrow, there will be time to address this urgent matter.

Thundersnow Drops Heavy Wet Blanket on Morris Park

This 15 inch blustery event made the previous morning’s 5 inch “wintery mix” look like a harmless dusting.  This storm was the real winter storm, not a December fluff festival that can be swept off the sidewalk with a broom. This was a heavy wet snow, that blew sideways and stuck to every surface it made contact with.  It was accompanied with lightning and thunder.  This is the snow that threatens trees that are covered with vines.

Around 10:00 last night we heard cracking sounds coming from the park.  They sounded like gunshots, popping off one after the other.  I knew what they were from the direction of the sound.  It was the Norway Maple grove (Acer platanoides) growing not far from the house, in a blighted area, so full of invasives it has actually been de-prioritized from invasive removal projects in favor of areas with large and diverse native populations at risk of emerging invasives.

morris park philadelphia
the thundersnow in Morris Park from the front porch

The forest was a pretty sight, the job of shoveling the front walk and the sidewalk was not. Always the worry of getting salt on the garden. Last year it was very possible that salt caused our cultivated wild Ginger (Asarum canadense) to have brown spots on the leaves.

Our Rhodie takes one for the team

The Rosebay Rhododendron (Rhododendron maximum) is such a good sport under our tenure. It is doing much better since we planted it in the yard after we left it in its nursery pot in the back alley for the entire summer of 2007, hardly watering it.

the snow stuck to every surface
Norway Maple splits apart from the weight of snow and grape vines

In the upper right section of the picture, the carnage is visible.  These invasive trees introduced from Europe, are dominating this one area, shading out native plants and trees with their dense canopy. They were covered with grape vines (Vitis spp.) and the vines were so dense on the trees, that they caught enough snow to weigh them down to collapse at 10:00 last night. This is not a loss at all for the health of the forest, however we have found many, many native and ecologically important trees destroyed by this process.

Norway maple morris park philadelphia
Norway Maple with Grape vines

Some of the most vulnerable native trees destroyed by the combination of Grape vines and snow are Tulip Poplar (Liriodendron tulipifera) and Sassafrass (Sassafrass albidum).  These are both fast-growing pioneer species, important in forest regeneration, something we take very seriously in an urban degraded forest situation. However, the cost to their rapid forest-building characteristics is their weak wood, easily broken in a compromised position.  Grape is a forest edge vine that does contribute food for birds and has an ecological value.  It is generally found on the rivers edge, or on other edges of forests.

However in a disturbed urban forest, the grape vine thrives, so much so that it maintains a forest edge state by overtaking any and all trees that try to grow.  In this state, other invasives such as Oriental Bittersweet (Celastrus orbiculatus) and Japanese Honeysuckle (Lonicera japonica) among a whole host of others, also climb over the tree saplings, creating the inpenetrable thicket, the death knell of the potential forest.   In the final stages of this commonly found environmental degradation, a monolithic aggregation of just a few species of plants remain. Contributing little or nothing to native birds and insects, what is left is a dead zone, completely incomparable in value and quality to the original forest that was once there.   Here, the invasive trees are being toppled by the native Grape vines (We are not absolutely sure of the native status of the local population, actually).  When an ecosystem is out of balance, all kinds of things can happen.

Tulip Poplar strains under the weight

The snow brings so many striking contrasts and great shadows. The forest we are used to on a day-to-day basis has been transformed drastically and with such a beautiful effect.  This winter we have had so many different types of snow events, each one with a unique stamp on the forest.  This most recent snowstorm is most characteristic of a mature winter in our Mid-Atlantic, Piedmont location.

The Tulip Poplar holds its own

So interesting how the snow collected on this fairly young Tulip Poplar.

Mature Tulip Poplars
The snow attaches to the north side of the trees
The Beech tree

Here, the Beech tree is really weighed down by the snow attached to the leaves still on it’s lower branches. Why the leaves stay on through the winter is still a mystery. What evolutionary advantage does this have?

The trees will survive

In this area, after this snowstorm, the rubber meets the road.  This is an area where we have removed many vines off of these trees during the fall, with this very situation in mind. The little trees are holding their own and are not broken or splitting. This picture is a testament to our success. For the winter of 2010-2011, these young trees are saved.  What a beautiful way to see our achievement.

Beech buds

The Beech (Fagus grandifolia) buds , here covered in ice, have a red color, beautifully illuminated in the sun.

Chestnut tree (Castanea dentata) weighed down

Just yesterday in the “wintery mix” discussion, this very tree was illustrated as a Fagacae family member holding onto its leaves in the winter like the Beeches and the Oaks.  Now its bent down under the weight.

The north side of an oak at the end of the Morris Park Road Path
This dogwood is really covered now

Just yesterday, again, this Dogwood tree (Cornus florida) was featured, with little clusters of snow mimicking its spring flowers. With a little imagination yesterday, that was possible, that a little winter snow could resemble a spring inflorescence.

Not so today. This is a whole different scene. Yesterday was the make-believe. Today is truly winter in all its glory. So, if its going to be like this, we wont mention spring anymore then. Not for now at least.

Young Beech is weighed down heavy

We  hope that this one will make it through these challenging times.

This beech survives

This little guy seems to be holding its own quite well.  (Fagus grandifolia)