From the Field - Crow's Nest Preserve

A call for projects

We've had good experience with Eagle Scout projects at the preserves. The "Deep Woods" trail at Crow's Nest was Mike Watson's Eagle Scout project; every time we walk there we are thankful to have it.

The preserve is in need of a couple more trails to connect existing trails to complete trail loops so that visitors don't need to backtrack. We also need some repairs to boardwalks and/or new boardwalks along the creek trail, and we could use some boardwalks on the trail that connnects with Hopewell Furnace, and a boardwalk to reach the cable bridge north of Pine Creek.

Eagle Scout projects are an opportunity for a scout to demonstrate leadership. The project is useful to the community and is greater than he can complete by himself.

If you are interested in these projects or know someone who might be, please call me at 610-286-7955.

The Hippocratic Oath of Land Management

For a while now when I give talks about managing invasive plants, I bring up the subject of the Hippocratic Oath of Land Management: First Do No Harm.

We should choose methods of conducting our work that have the least negative impact—or fewest unanticipated consequences—on the land and habitats we manage.

It means, for example, avoiding unintended disturbance in removing invasive plants since other invasive plants may take advantage of that disturbance.

It means not compacting soil or creating ruts by driving across a wet field, even if it means walking some distance carrying the equipment. It means being thoughtful and aware of the impact of every action. We need to pay attention to the possibility of unintended changes of species composition, hydrology, geomorphology, forest stucture, nutrient availability, etc.

I had thought that applying the medical analogy of the Hippocratic Oath to land management was a unique idea, until I read the cover story in the October – December issue of Conservation In Practice. Entitled "Do No Harm" the article is by Mark Jerome Walters (29-34).

It's mainly about how efforts to save the endangered Hawaii raven actually hampered the species' recovery. "The lure of technology seems to tip the balance toward always 'doing something' rather than erring on the side of doing nothing to minimize the risk of harm" (34). Without the knowlege of how to study the birds without frightening them, researchers disrupted nesting and reproduction. Walters has written a book about what happened: Seeking the Sacred Raven: Politics and Extinction on a Hawaiian Island (Island Press, 2006).

[I call this inability to study something without affecting it (you guessed it!) the "Heisenberg Uncertainty Principle of Nature Study"—based on the quantum physics wave-particle conundrum. Although this is not a proper description of the actual Heisenberg Uncertainty Principle (see the Wikipedia entry) it is worth keeping in mind that researchers often do affect their study subjects.]

I don't mean to imply that we shouldn't study nature or manage our preserves, only that we need to be aware that the things we do may have unanticipated consenquences. And of course, we can't ever anticipate all of the unintended outcomes of our management.

There are also limitations to the medical analogy of the Hippocratic Oath. An ecosystem is not as static as a human body, for example. What we see today, what we take for granted as what a place is, is only a snapshot of a dynamic, ever-changing web of relationships among a changing cast of characters.

Our Third Responsibility

I often remind the people who work here—summer interns, preserve assistants, or volunteers—that getting the job done is our third most important responsibility in land management.

Working safely, and ensuring the safety of others is our first responsibility.

Protecting the equipment is job #2. Since we share equipment, making sure the tools aren't damaged is also a safety issue. Equipment and the training to use it safely is also an investment in our ability to get the job done.

So completing the task at hand, while very important, ranks third.

What I like most about this job...

This holiday weekend, aside from Thanksgiving Day itself, was filled with warm sunny days perfect for a walk on the preserve and many people took advantage of the fine weather. I had several pleasurable meetings with preserve visitors who were kind in expressing their thanks for our work protecting the land.

More than anything I enjoy sharing the preserve with others.

Tree Hugger

I suppose after writing a post about cutting down hazard trees (see below) I should affirm that I prefer my trees "on the hoof"—that is, standing, growing, shading, in the full majesty and grace of their size, slow and persistent growth and beauty.

There is a satisfaction that comes from a skilled job well done when I remove a hazard tree but one has to respect the years that it took to grow this creature. We remove a few: damaged, dead or decayed—and a threat to a target—while we protect the vast majority of others...

Hazard Tree Work

At Natural Lands Trust we have a hazard tree management program overseen by Tom Kershner, arborist and manager of Gwynedd Wildlife Preserve. Each of us monitors potentially hazard trees on the preserves, consulting with Tom as needed. We each received training from Bill Graham at Morris Arboretum on evaluating defects; we also have a few books and Forest Service publications on the subject.

A hazard tree is defined as a tree that has both a defect and a target. The defect could be a cavity of rotted wood or some other sign of potential failure. Or the tree could be dead, something that happens to all trees someday and which results in its eventual return to earth.

But the tree must also have a target to be designated hazardous. Standing dead trees in the forest are good wildlife trees, providing dens for animals and insects for birds, and we leave them for the habitat they create. But a dead tree that might fall in the road is a problem.

So each hazard tree is rated 1 - 4 and each target is rated 1 - 3 (for example, a bench is a much higher target than a trail; public roads are all #3's). We remove all seven's and sixes and evaulate fives case-by-case. Some fives and fours we leave standing but monitor twice each year.

I keep track of the hazard trees I monitor in a database. It tells me that we have removed 49 trees (from a couple miles of road frontage) at Crow's Nest in the last ten years. (There were a few other small ones that did not warrant the paperwork.)

Some trees I take down myself. Other that pose a greater challenge Tom helps me with. And those near wires we hire a full-time arborist to prune or remove (see photo above).

Going into this year we had only six trees I was monitoring, down from 30 a few years ago. But nine trees were found newly dead this year along Hopewell Road, and all of them made the list. For most of them I think it was the natural process of forest maturing that killed them—there isn't room or resources for every tree to make it to full size. But all of them were near the telephone wires and Hopewell Road, so we hired local arborist Norm Koontz of Chesapeake Tree Care, who used his bucket truck to reach over the wires and remove the hazards.

Some of the removed trees are left in the woods to rot and return nutrients to the forest. Where there isn't enough room for that we cut some up for firewood and if necessary chip the branches for mulch for the trails. We've even gotten a few beams for the barn from sound wood in these trees. And when a storm comes there is less cleanup because we have already removed some of what might have fallen.

Farming at Crow's Nest

We lease 172 acres of Crow's Nest to a local farmer, Frank Hartung, who has farmed this land for many years, as his father Ken did before him. He plants a conventional rotation of field corn, soybeans, winter wheat, winter rye, and hay.

The farming is done following a Conservation Plan prepared by the Natural Resource Conservation Service (NRCS), a cooperative project of the Federal government and Chester County. The crops are laid out in strips that are parallel to the contours of the terrain, so that soil does not wash away down a row, and so that no more than 100 feet wide of slope is in a single crop. Seasonally dormant crops such as corn alternate with winter-growing crops such as winter wheat, for example, so that erosion in one strip is stopped by the next.

The field corn is usually harvested by combine. The kernels are loaded onto a truck for animal feed, and the stalks are chopped and left on the land as a mulch to reduce erosion and return organic matter to the soil. (In a drought year when corn ear production was severely reduced, some stalks were harvested instead for sileage, another kind of animal feed.)

The soybeans are also harvested by combine, as in this photo, which also shows the crop strips. Winter wheat and rye are cool-season crops that are planted in the fall and harvested in the spring when they mature and set seed. The seeds are stripped off, again as a grain for food, while the hollow stems are baled for straw and used for animal bedding.

Hay is a perennial crop, largely alfalfa, that is grown in one place and harvested for several years by cutting in late June and perhaps again in August. The cut grasses are left to dry in the sun for a couple days, then twirled into windrows and baled. Hay is used as the fiber in large animal feed.

Frank works cooperatively with other farmers in the neighborhood, sharing specialty equipment and storage space.

Cooperation in Afforestation

Being part of a system of preserves means that field staff works cooperatively. Last week we planted 800 seedlings at Gwynedd Preserve, starting the process of succession from field to forest in an old farm field near the Wisahickon Creek. Here Joe Vinton operates an auger to prepare planting sites and Erich Estes knocks the soil off the auger after each hole. Others follow behind planting trees and pounding in stakes and tube tree shelters to protect the seedlings from deer browse. Staff will mow between the trees for a few years until the trees become established and begin to cast shade; this helps control invasive plants such as multiflora rose and Oriental bittersweet that might otherwise take over the field. Gradually the plantation look will give way to a more natural forest.

This process is called afforestation—planting a forest where there hasn't been one in a long time, and is a technique Natural Lands Trust uses to establish forest on several of our preserves, many of which are former farms (closed-canopy forest reduces maintenance, protects habitat and stream quality, and is the natural vegetation cover in our region).

This is different from reforestation—replanting a forest immediately after a forest has been harvested. Although this has its own challenges, unplowed forest soils may be more hospitable to trees and there are likely forest tree seeds in the soil's seed bank. Since we don't cut down the woods on our preserves we don't do reforestation.

Working together as part of a crew means the trees get in the ground quickly and the job gets finished in the narrow window of opportunity we have for planting.

Digging Holes

Off and on over the last couple weeks I have been installing a fence to go around an expanded vegetable garden, some of which will be a teaching garden for the preserve: kids will plant seeds and seedlings in the spring WebWalkers and Spiderlings programs, and have a chance to harvest some at summer camp or at the fall programs. This sounds more smooth than is likely to work out, but there will be something to plant or harvest in the garden for any of the growing season programs.

Although I could have borrowed a power auger I am digging the post holes by hand, since the soil here is so rocky that the auger would bounce off the rocks or repeatedly break its shear pins. There is a certain Zen to the repetitive actions of digging: loosen the soil with the iron digging bar, scoop out soil, repeat.

One of the holes I am embarrassed to say took an hour to dig (or perhaps I should be relieved that they all didn't take an hour). There was a massive rock in the precise spot the post needed to go—picket fencing is not flexible about post locations. Here's a photo of my truck about pull the rock away.

Well, at least that's how big it seemed when I pulled it out.

The Rhythm of the Seasons: Work

We are passing the seasons of mowing. The mile-a-minute, a perniciously fast-growing annual vine, has been hit by frost and is finished for the year. So I've moved on to the next project: this is a good time of year to identify and pull Norway maples. Although we have no mature, seeding trees left at the preserve, there are some landscape trees in the neighborhood and each year I pull thousands of seedlings.

We're also doing some vine control, particularly of Oriental bittersweet.