From the Field - Crow's Nest Preserve

The blog has moved!

Hello Readers!

The Crow's Nest Blog has moved! We've combined all of the Natural Lands Trust preserve blogs into one, so any new posts will be made there. You can find that blog here.

We hope that you'll follow us to the new blog--it'll have everything that this blog has (including an archive of all the entries made on this blog), plus plenty of other interesting posts by the other preserve managers.

(Please note that this weblog will no longer be updated.)

Camp Reunion!

We had a wonderful afternoon Saturday at the reunion of summer 2006 Crow's Nest campers. We played games, went on a hike, made crafts, and got muddy. We crossed the creek on the wire bridge and compared our summer and winter experiences there. These kids are looking forward to summer camp 2007. The theme is water: meet creek critters, water cycle obstacle course, French Creek Regatta, drippy olympics, build a beaver habitat, waterwheels & pumps, and lots more.

General registration opens at the end of March. Please call 610-286-7955 if you'd like more information or a brochure.

Spring WebWalkers & Spiderlings

At the end of our winter WebWalkers and Spiderlings programs we tapped some maple trees—red maple, not sugar, because we have more of them—and are now collecting the sap. Red maple (Acer rubrum) sap is not quite as concentrated in sugar as the sugar maple (Acer saccharum) but can still be made into syrup.

The kids in the photo are doing something else, too. They're are listening through a stethescope that Sean is holding against the tree, listening for the sound of the sap rising. It isn't loud but there is some swooshing noise. Remember, the theme for the winter programs was "Things we cannot see."

We'll begin spring sessions of WebWalkers on April 12 and 13. The programs cost $25 per child for the six-week program. Please call for more information.

March 17 March for Parks

Our neighbors Hopewell Furnace National Historic Site and French Creek State Park will be hosting programs to celebrate their 11th annual March for Parks. After a flag raising ceremony at Hopewell on Saturday at 9:30 participants will recieve supplies to do some trail clearing and roadside cleanup. Park-provided snacks and drinks will complete the morning of volunteering. At 1 pm Hopewell rangers will lead a hike to some lesser-known historic sites at the Furnace.

For more information about the event please give me a call, 610-286-7955.

Amphibian migrations

With it having been so cold lately it might be easy to forget that we are still expecting the spring migration of salamanders and frogs to area wetlands. They usually migrate at night when the ground is wet during or after a rain and it is 40 degrees or more.

Tonight may be the first night this year that fits the bill and area residents are expecting to see some salamanders crossing. To avoid conflict with them on the roads, try to avoid travel at this time, particularly on back roads through wooded areas and near wetlands.

If you'd like more information on local efforts to assist with the road crossings and collect data on the amphibians doing the crossing, please give me a call at 610-286-7955.

A gardening warning

It is a beautiful day outside, and I know what you gardeners are thinking. You want to be out there in the yard, cleaning up and maybe turning over the soil.

Don't. It's too wet. The ground is still frozen a couple inches down and the surface is sticky. Manipulating soil while it's this wet will cause it to lose its structure—the arrangement of soil particles and air space. Plant growth will suffer.

Spring will be along soon. Start seeds indoors or go out for a hike—just be sure to wear boots.

Connecting the dots

On May 27, 2005 I wrote about an irruption of a population of fall cankerworms (Alsophila pometaria) that had stripped the woods bare in the spring of 2004 and were doing so again in 2005 (but it never got as bad).

And on December 2, 2005 I wrote an entry called, Night of the moths. I experienced thousands of moths flitting all around me despite the cold weather.

It never occurred to me until yesterday that these two natural events are almost certainly related.

Tim Marasco from the Pennsylvania Department of Conservation and Natural Resources was a speaker at yesterday's conference. He showed a map of forest defoliators that included fall cankerworm; they affected a broad swath of the state following the ridges from northeast to south central PA, sparing the southeast. But there was one non-contiguous area affected that was clearly in and around French Creek State Park. Tim mentioned this anomalous population and that he was in this area when the adults emerged; the moths were all around "just like falling snow."

The light bulb went on.

That's exactly what I saw. The moths I saw in December were likely the adult stage of the larvae I had seen that past spring. Of course there is a multitude of other moth species it could have been, even just in the family that contains the fall and spring cankerworms (Geomedtridae). But it is exciting to have an "aha!" moment even at this late date.

Low-hanging fruit

People often ask if there's something they can do for the environment. Here's an easy one:

Don't move firewood far from its source, for example when traveling to go camping.

Yesterday I attended training by the Pennsylvania Department of Agriculture and Penn State Cooperative Extension. One of the sessions was about forest pests and included a discussion of the emerald ash borer (Agrilus planipennis) a beautiful beetle that threatens ash trees. The beetle (known in shorthand as EAB) has damaged or killed millions of ash trees in affected areas of five states but has not been found in Pennsylvania so far. EAB, a native of Asia, was first discovered in Michigan in 2002.

Counties where it is found have been quarantined but there has been some spread to other states. Firewood is one potential vector for its movement. Ash trees are beautiful and the wood is strong (it's used for baseball bats). Emerald ash borer has its own website.

Another ending, also a beginning

Quick, what was the date of the final leaf drop of deciduous trees last fall? Even if you keep a garden journal that day might not have the same weight as that of the first tomato you picked or the first trout lily bloom you spotted in the woods.

I've mentioned before that we seem to be better at commemorating beginnings in nature than endings.

Researchers studying deer would like to know what that date was last fall, presumably to know how long deer have been without that source of forage (the succulent buds of this coming years' growth are their current food).

Fortunately we have dated photos that show fall color still on a few trees before November 5 but not after November 10. And we have notes on my timesheet from when I was pulling out weedy Norway maple seedlings, among the last of the leaves to drop (and therefore a good time to spot them).

Student Research: "How to Conserve Native Plants More Effectively"

The Senior Seminar in Ecology last semester at Bryn Mawr College made use of Crow's Nest Preserve for fieldwork and as a case study. The focus of the class was the value of ecosystem services—those functions that support human life and well-being but are not usually commodities bought and sold: clean air and water, erosion control, climate regulation, and pollination.

The work brought up the importance of collecting raw data from the preserve: it would be difficult to know too much about a place!

Daniela Miteva wrote a study entitled How to Conserve Native Plants More Effectively that included an effort to estimate the monetary value of the native plants at the preserve as well as predictions—using flower and bee abundance data—of the impact of habitat disturbance and fragmentation on the native plant communities in Crow's Nest's meadows.

The benefit of the native plant habitat includes intrinsic values of its ability to support wildlife, manifest biodiversity, and contribute to the relative stability of an ecosystem. The report also estimated the value to Natural Lands Trust of the native habitat as a place to host environmental education and research projects, and to promote hiking and walking, bird and wildlife watching and nature photography. The study also estimated the value visitors place on the preserve (how much are they willing to pay to travel to get here) and the increase in market value of homes located near protected open space.

The study also accounts for management costs to maintain natural areas: that minimum intervention to keep a meadow open and free of invasive plants. It doesn't, however, make an attempt to quantify future benefits (with inflation) of open space protected today.

The part of the study that most affects our land management is the flower and bee abundance surveys. One of the conclusions is that the factor that most affected native bee abundance is the presence of forested sites within 2,300 meters; these provide the bees' nesting sites.

Fortunately Crow's Nest's meadows are embedded in a matrix of forested areas; the study also suggests that loss of surrounding continuous forest habitat could increase management costs here long-term.

The study also concluded that bee species diversity is most affected by frequency of mowing. Most of our meadows are mowed once per year to control invasives and keep them open. But sites that had the greatest number of different bee species were sites that had not been mowed for 2 - 3 years, so it may make sense for us to have more "reserves" of less-frequently-mowed areas, something I have begun to experiment with this winter.