Advantage: Invasives

Invasive shrubs manage to overwhelm many ecosystems by more effectively exploiting the resources available in their environment.  They are currently busy demonstrating one of the characteristics that allows them to claim such a dominant role in any ecosystem they occupy.  Plants use sunlight captured by green leaf area to fuel the photosynthetic process that supplies the energy needed for plant growth and reproduction.  Invasive shrubs, like the Bush Honeysuckle shown above, produce leaves quite early in the year and hold those leaves into late fall.

Our native plant species have evolved a sequence growth that allows each species to capture the sunlight necessary to its survival.  Spring wildflowers generally complete their growth early in the year and by the time the trees have developed their leaves, the early plants have stored the energy they need to produce seed and carry on to the next year.  At Blue Jay Barrens, the leaves of invasive shrubs develop in advance of most of the early wildflowers and deprive the native species of their needed sunlight.  Eventually, the invasives form a solid thicket and the natives disappear.

The vining Japanese Honeysuckle does the bush type one better.  In some years, the previous year’s leaves remain green through the winter.  The leaves to the upper left are from last growing season and the rest are new to this month.  As long as the leaves are green, photosynthesis can occur.  While native plants are in their winter dormancy, Japanese Honeysuckle grows continually stronger and more able to compete for a place in the landscape.

Autumn Olive is quick to take advantage on the slightest winter thaw.  The long leaf season of these invasives allows them to put on some tremendous growth.  This four foot tall specimen represents only two years of growth.  In that short time it went from a seedling, barely reaching above the leaf litter, to a major producer of shade.

These leaves are the result of about two weeks growth.  The growth will soon begin to elongate into the production of new stems.  The shrub could easily double its height and quadruple its width before the end of this growing season.  That is, it could have if I had not cut it down and sprayed the stump with herbicide.

Seedlings may take a couple of years to develop a root system capable of sustaining rapid top growth.  This seedling managed to hold onto one of its leaves for the entire winter.  The benefits from this one leaf have probably greatly increased its competitive edge.  If I hadn’t cut and sprayed this little guy, it could have reached over two feet tall by the end of summer.

Multiflora Rose is another that is quick to put its leaves into play.  Frosts and freezes may cause some leaf damage to these shrubs, but the damage is generally restricted to shrubs growing in the open.  Shrubs growing beneath the canopy of taller plants are often protected from frost damage.  If some leaves are killed, they are quickly replaced.  All of these species are highly susceptible to a cut stump application of glyphosate during this early growth season.  I usually carry my pruners and spray bottle with me everywhere I go during this time of year.  Fortunately, I am now only dealing with newly arrived invasives, so a pair of hand pruners is all I need for the job.

Random Mowing

It has been a couple of years since I’ve done any large-scale field mowing with the brush mowers. For about 12 years I followed a planned three year rotation that had me mowing five to seven acres each year. The sole reason for the mowing was to locate and eliminate trees and shrubs invading the field. I purchased my first DR field and brush mower in 1992. That mower, which I refer to as the DR or The Doctor, followed the old Bachtold Brothers design. The DR was lightweight and would mow practically anywhere, but only had one speed, moderately slow, and with age its performance began to decline. In 2009 I purchased the newer model shown above, which I generally referred to as JR or Junior. JR took over the duties of field mowing while the DR retired to more lightweight duties.

When I first began mowing fields, I would mow over the invasive plant and mark the location of the stump using a 4”x5” red plastic flag mounted atop a 3 foot wire shaft. In the early years I was averaging about 750 flags per acre. Mowing was done in November and December, and I would return to the fields in April or May to apply glyphosate herbicide to the developing stump sprouts. This strategy worked extremely well in fields that were experiencing a heavy infestation of invasive woody plants. In recent years, most areas of the fields are experiencing invasion rates low enough to allow me to individually treat the invaders without a wholesale mowing of the field. Most of my current mowing is done in small isolated areas that still require a more heavy-handed management approach.

Here is a good example of a small area requiring some special attention. This long triangular area wedged between an old fence row and an intermittent Creek has some special needs that are best met by mowing. This end of the field is crowded with Dwarf Sumac. If left unchallenged, it would eventually create an impenetrable thicket. The far end of the field was once a multiflora rose jungle. I use blue flags to call attention to special features such as holes, rocks, old fence wire, or plants that should be left untouched. In this case the blue flag identifies a small oak that is to remain in this field.

The finished product. The mowing does not kill the sumacs. After two or three mowing seasons they will once again reach the point where they will need to be knocked back. Managed in this way the sumacs pose no threat to the tallgrass or other prairie vegetation, but they are still able to produce food for the various leaf and seed eaters that seem to prefer this species.

A photo taken from this angle 10 years ago would have shown nothing but a solid wall of multiflora rose inches from your face. I have many photos of that type, but they are virtually useless as helpful before photos for documentation purposes. The massive roses went up to the point where the light-colored grass begins. Since old seeds continue to sprout to produce new plants in this location, I mow it at least every other year to help locate the new multiflora rose plants. The red flags identify young multiflora rose plants that need to be treated with herbicide. Only eight rose plants were found in this one third acre field this year. The blue ribbon marks one of several native rose plants that I am trying to encourage.

The area around the main trailhead is mowed each year. This is one of only two areas that get such attention on an annual basis.

A mixed bag of invasive shrubs once grew here, but now I only have to deal with the occasional new recruit. My primary reason for continuing to mow this small patch is to get rid of the scattered tallgrass and plant stalks that interfere with enjoying the wildflower displays occurring here during spring and early summer. The Monarda bloom is especially attractive. The floral display along with its attendant butterflies should not be sullied by a mass of year-old stalks and stems.

It’s nice to have reached a point where large-scale mowing is no longer necessary to achieve my management objectives, but I kind of miss the activity. It was good exercise and I found it relaxing to spend the day just walking round and round and round the field. Fortunately, I have plenty of other work to fill up those hours no longer needed for mowing activities.

Sick Deer

One evening last week I had an interesting encounter with a Whitetail Deer.  I had just set my tools down and was walking forward to take some before photos of a planned work area, when I spotted a buck deer about 30 feet up the hill from me.  The deer was trying to shed its antler by pushing it against a thick grape vine.  It was obvious from first glance that the buck was not exhibiting the behavior typical of a healthy deer.

The antler slipped from the vine and the deer lurched forward, the grape vine now arching above its neck.  Here it stayed for several minutes.

The deer was breathing heavily and its eyes were kept partially closed.  At this point I thought the deer might just be exhausted from trying to dislodge the stubborn antler.

After its rest, the deer circled around and came at the grape vine again.  It had no better luck this time and circled around for a third try.

Leaving the deer to its business, I went ahead and took a few photos of my planned work area.  I heard some branches breaking and turned in time to see the deer stumble away from the grape vine, get tangled in a small shrub and stagger down the hill to fall right on top of my tools.

The deer stayed down for about a minute before getting back on its feet.  Its body looks to have lost a lot of muscle.  It was here that I began wondering if the deer was just on the downhill end of a long life or if it was diseased.

After standing for a couple of minutes, the deer began to walk in a tight circle.  The video above shows part of its roundabout journey.  Before filming, I was able to sneak in and get my bow saws and tool bag out of the way, but each time I moved in, the deer lunged in my direction.  Not wanting to risk a deer related injury, I left my pole saw and gloves to fend for themselves.  The deer seems quite adept at stepping on the pole saw on each circuit.

Eventually, the deer worked its way down the trail.  In the half hour between the taking of this shot and sundown, the deer traveled about 60 feet and fell down four times.  The following morning I found the deer another 200 feet down the trail.  It was down and didn’t look like it would be getting up again.  I reported the presence of a potentially diseased deer to the local Wildlife Officer who arrived to put the deer out of its misery and collect samples to be tested for disease.

Pole Saw

My previous post generated a question concerning how I managed to remove the top limbs from a leaning tree that was obviously too high above the ground to be easily reached. In answer to that question, I’m introducing a valuable land management tool known as the pole saw. This is basically a pruning saw mounted to the end of a long pole. The top section with the saw mount is 6 feet long. Pole length can be increased through the addition of individual six-foot extensions. My first experience with this tool was in a pine plantation where this type saw was used to remove limbs from trees that were destined to become saw logs. 

The pole saw is an ideal tool for removing tree limbs that cannot otherwise be reached from the ground. A perfect example of its usefulness is in dealing with this dead tree top which has lodged itself in the fork of a live cedar and now poses a threat to people traveling the trail below.

If I was looking to be the star of an epic fail YouTube video, I would attempt to cut this tree by either standing on the very top of a folding ladder or by leaning my extension ladder against the horizontal trunk while I proceeded to cut my support out from under me. Since I hate to waste time by recovering from injuries, I try to perform tasks in as safe a manner as possible.

The pole saw allows me to stay securely on the ground while I safely work at dismantling the treetop. Even though the total length of my saw reach is 12 feet, the need to stand off to the side while operating the saw only allows me to effectively work an extra eight feet above my normal reach.

In most cases, it’s necessary to begin your cut on the upper side of a branch and work your way down. Cutting your way from one side of the branch to the other often causes the branch to twist and trap the saw blade in place, making you feel pretty stupid as you stand there wondering how you’re going to retrieve your saw.  You also don’t want the cut limb to come crashing down on you, so it’s not wise to be cutting with the saw held vertically above your head.

Not all cut pieces are obliging enough to fall in such a convenient position. I didn’t even have to bend over to shoulder this log for its trip to the brush pile.

In addition to the saw blade, the pole saw head has a hook that can be used to coax snagged branches out of the tree. The hook shape allows the tool to be used for both pushing and pulling. In tight situations or with densely tangled branches, the saw blade can be removed from the hook to eliminate the chances of the blade getting damaged or stuck.

I’ve had this tool for nearly 30 years and it is now on its second blade. It doesn’t get used often, but it’s awfully nice to have around when the pruning job calls for extra reach.

Random Tree Cutting

I’ve been working on a lot of small management jobs that have been on my list for some time now.  Several of these have to do with trees that are threatening to fall on or to shade out desirable species.  When a tree begins to lean over, the area covered by its shadow increases.  Lateral branches turn upwards and eventually form what amounts to a line of sapling trees growing along the trunk of the leaner.  New growth adds weight that will eventually make the tree fall.  The Wild Black Cherry tree above is not only causing a thinning of grass in the shade zone.  It is overtopping a grove of Redbud and Carolina Buckthorn that will suffer some severe damage if landed upon by the falling tree.

Removing the tree eliminates both the shade hazard and the threat of physical damage to surrounding vegetation.  Unlike most upright trees, leaning trees offer a limited direction toward which they will fall.  Fortunately, a good cut and a little bit of shoving allowed me to drop this tree without damaging any of the shrubs I was trying to protect.

Actually bringing the tree to the ground is usually the least time consuming part of the process.  It’s taking the tree apart and moving it to a brush pile that takes up most of my time.  When I don’t have time to finish the job before days end, as was the case here, I leave the branches in a conspicuous place where I won’t fail to clear them up later.  In this case I left them blocking one of the main trails leading from my house.  There’s no way I can forget about them being here.

Here is another leaning tree, also a Wild Black Cherry.  This species accounts for 90 percent of the leaning trees I encounter.  In this case, the tree is threatening a cluster of oak saplings seen on the right side of the photo.

I didn’t have time to take the whole tree down before it got dark, but I did remove the lateral branches that produced the majority of shade.  If I don’t happen to make it back to this site this winter, the oaks will still be able to receive needed sunlight next growing season.

Some trees are removed just to eliminate the shade they produce.  This Tuliptree was shading the same cluster of oaks being threatened by the leaning cherry.

The oaks in question can be recognized by the dead leaves that they hold into winter.  These persistent leaves make it fairly easy to spot oaks in a grown up field.

With the shade producers removed, the oaks will respond by rapidly increasing their size.  Removed trees were intentionally cut so as to leave a tall stump.  The stumps will be shortened this spring, and herbicide will be applied to the fresh cut.

Removal of this Tuliptree has been on my to do list for several years, but there always seemed to be more urgent activities that kept me from the task.  Tuliptrees are fast qrowing and have the ability to shade out a large area of grass, so it’s best not to let them go for very long.  Notice just to the right of the Tuliptree is a Wild Black Cherry leaning out from the old fence row.  The original tree top has died and a side branch has grown up to produce a nice sized tree.  Eventually, the leaning trunk will not be able to sustain the weight of the new top and the tree will fall.  When it falls, it will most likely hit the Flowering Dogwoods in the center foreground of the photo.  I’ll probably have to take the cherry down before it falls on its own.

I dropped the Tuliptree right on the trail.  There’s no way I could possibly forget to clear it away.

There are some pretty widely spaced growth rings here.  Ten years ago I could have cut this tree with my loppers and carried the whole thing over to the brush pile.  I now aggressively attack the small trees invading the grassland areas, so I won’t have trees of this size to deal with later.

One disassembled tree ready to be carried off.

The trail is once again open for business.

Three Tuliptrees and two cherries were added to this already existing brush pile.  The logs were positioned for maximum use by fence lizards and skinks.  Whether or not I remove more trees this month will depend on the weather.  I’ve already taken care of the worst offenders, but it would be nice to get just a few more.

Removing Fallen Trees

January has been a rough month for getting any heavy work done in the field. Warm temperatures and frequent rains left the soil highly vulnerable to compaction and other damage resulting from inappropriate management activities. It has only been in the last few days that I’ve been able to perform any intensive work, and that has been limited to hilltop areas that drain and dry out quickly. I removed the girdled trees that had fallen in my planned grassland area. A few stumps, some scattered twigs and flattened areas of grass were all that was left after I finished picking things up.

Following the removal of the downed trees, I brought in JR, the brush mower, and mowed the entire work area. Removing the trees and mowing the field were not necessarily required activities in my plans to convert the area to a grassland condition. The fallen trees would quickly decompose and the tall prairie grasses would eventually take over the site. My actions here were in response to the need to easily access the area to locate and eliminate invasive shrubs. Keep in mind that it’s only been a few years since this particular patch of ground was a thicket of Multiflora Rose and Autumn Olive. The site still harbors viable seed and is producing several new seedlings that must be found and killed each year. Anything that interferes with my ability to travel freely through the area in search of these invaders must be removed.

The area is planned to be grassland, but it will not be completely free of trees. This Blackjack Oak, Quercus marilandica, currently surrounded by the standing dead, will one day be surrounded by tall native grasses.

This double trunked Flowering Dogwood will also be left alive. An anthracnose outbreak nearly three decades ago eliminated this species from the woodland understory at Blue Jay Barrens. It has still not returned to the woods, but a few survivors along the field’s edge became the progenitors of flowering Dogwood trees growing in the open fields. I allowed this species to remain in certain designated areas of the fields, and now have dozens of nice sized specimens producing copious amounts of fruit and seed each year. This individual is doing quite nicely despite one of its trunks being disfigured by the choking embrace of a Japanese Honeysuckle vine, yet another invasive species needing to be controlled here.

After mowing the area, I noticed a leaning tree poised to land directly atop the Flowering Dogwood, and a pair of grape and honeysuckle festooned trunks similarly aiming towards the lovely oak. Not wishing the oak or dogwood to be damaged by their menacing neighbors, I removed the threats myself in a safe and controlled manner.

In order to facilitate invasive shrub control, I also removed some fallen branches from the sumac patch.

The patch of Dwarf Sumac was left intact and standing dead stems were not touched. These sumac thickets harbor their own suite of boring beetles, leaf eaters, lichen colonies and other organisms drawn to this type of habitat. I tried to disturb it as little as possible.

The removed wood roughly tripled the size of the brush pile at the edge of the field. Logs were placed on the east facing side of the pile. Skinks and fence lizards are particularly drawn to logs situated in this manner.

Tree branches were dismantled down to individual stems which were then piled as densely as possible. This fosters rapid decomposition, so the pile quickly reduces in volume. The logs are stacked so that they will fall back into the pile as the small branches decompose. It has been pointed out to me numerous times that my brush piles do not follow the classic wildlife management design, which has the goal of providing escape cover to game mammals. My piles serve a broader interest and are utilized by a wide range of reptiles, birds and mammals.

The dead trees will continue to fall for the next couple of years. During that time, the tall prairie grasses will move in and become established. By then the incidence of invasive shrubs should be limited to new arrivals carried by birds as seeds from neighboring properties. For now, I’m pleased with the way things are progressing on the site and hope that all continues favorably.