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Archive for January, 2007

Golden Eagles and Wind Energy

I wrote recently about research that was done to find out what effects wind turbines might have on migrating songbirds (see http://natlands.typepad.com/from_the_field_mariton/2006/12/wind_power_and_.html)  The Pennsylvania Game Commission just announced on their website that they will be partnering with the National Aviary and Carnegie Museum of Natural History to research migration patterns of Golden Eagles in Pennsylvania.  (To read the press release click http://www.pgc.state.pa.us/pgc/cwp/view.asp?Q=171118&A=11).  The Appalachian Mountains in PA are an important migration corridor for Golden Eagles.  Many of these ridges are also targeted for wind turbines.  So, it is great that the Game Commission and their partners are taking this proactive step to research migration patterns that can lead to informed placement for wind power projects.

Wind farms on PA ridges are increasing.  As I said before, I support wind energy, but we should be able to harness the wind, and at the same time have minimal effect on the species using these areas, whether for migration or daily travel.  We should also be able to decrease the amount of electricity that we use each day.

Research & land management

This past semester students enrolled in Patty Zaradic’s Senior Seminar in Ecology at Bryn Mawr College prepared papers on research they conducted at Crow’s Nest Preserve.

The themes were based on evaluating the ecosystem services of various aspects of the preserve. Topics included the value of native bees at the preserve in pollinating local crops, the values (and strategies for conserving) native plants, the value of carbon sequestration in the preserve’s trees, the economic value of deer management, and the ecosystem services performed by beavers.

The students visited the preserve and in some cases laid out study plots. In other cases the preserve was compared with data collected elsewhere. We scoured our records for plant lists and poured over maps (ground-truthing the data on the maps with current land use conditions). We surveyed hunters and compared the data with statewide trends.

The projects pointed out a need for more raw data from the preserve: we haven’t done a blooming calendar in several years and we can always use more baseline species and natural community lists.

And the projects also pointed out some ways we might adapt our management of the preserve: for example, leaving more areas in a 2 – 3 year rotation of succession (rather than annual mowing of meadows) conserves habitat for a greater diversity of native bee species.

Over the next few weeks I will write a short description of the projects on the weblog and some of their implications.

This week I am cutting multiflora rose and vines with a hand held brushcutter, selectively cutting back the undesirable species while preserving as much as possible of the native vegetation. Some of the areas I am working in have been cut and sprayed before so I am just doing a very precise follow-up to the earlier work and it is progressing more quickly than the original management. Other places I am just getting to for the first time and I am using a power-pole pruner (a chainsaw on a pole) to cut the thick bases of the invasive species.

Caveman T.V.

Marsh_hill06_ii_090This Saturday night, Mariton has its Caveman T.V. program.  We will sit around a campfire on a cold evening.  Watching a campfire is mesmerizing.  Watching it with your clan is probably more entertaining and educational than most things actually on television.  Maureen and I are still discussing what food will be offered.  No woolly mammoth, but we will have some nostalgic treats like s’mores and warm cider.

Chances are good that we will hear owls, and we might even hear foxes calling.

Marsh_hill06_ii_086The campfire is from 6:30 – 10:00 p.m.  (You can arrive after 6:30 and leave before 10:00.)  Bring folding chairs and dress warmly in layers (you might want a blanket too).  The weather forecast is for a cold night.  Please call ahead (610-258-6574) if you plan to attend.  If no one calls, I won’t build the campfire.

Trail Trimming

I recently finished trimming back the edges of Mariton’s trails.  Using a weedwhacker with a metal saw blade, I cut back woody vegetation for three feet of both sides of the trails.  I try to do this every few years.  Of course, during winters with a snow pack, I usually can’t accomplish this job.

The main reason I do this is to keep trees and bushes from growing in on the trails.  Spicebush (Lindera benzoin) in particular has a tendency to poke its branches into the trail space at eye level.  By keeping the little saplings cut back, I only have to trim back a few branches.  Tree seedlings within a foot of the trail edge will eventually become trees on the trail.  These trees are more likely to  become hazard trees because of the traffic on their root systems.  Finally, it keeps the multiflora rose (Rosa multiflora) and wine berry (Rubus phoenicolasius) trimmed back.  These two tend to arc into the trail and scratch bare-legged hikers.

I do this work in the winter, so that I target only woody plants.  Cutting the edges back now means that I will have less trail maintenance during the summer (when I don’t have the time).  It also means that there will be less impact on wild flowers and their developing seed heads.  Because the woody plants have much of their energy stored in their roots right now, they will grow back (just not enough to poke into the trails this summer).

One of the benefits that I have noticed from this edge trimming, is that more sunlight gets to the trail edges.  So, now we have more wild flowers right along the trails.  This is great, because now you can admire and study these beauties without stepping off the trail.  One of the tenets of the "Leave No Trace" philosophy is to stay on trails to protect plants, and to keep soil compaction in a discreet manageable location.

Copy_of_trail_trim_012307_002Copy_of_trail_trim_012307_003Right now, you might see a difference.  In May, when things green up, it will be difficult to tell that I did this work in January.  (Before on the left; after on the right.)

Rhododendron Leaves

Copy_of_rhodies_012607_001The frigid temperatures this morning caused the rhododendron (Rhododendron maximum) leaves to roll up.  Rhodies are one of the flowering, broadleaf trees in our area that keep their leaves during the winter.  While it allows them to photosynthesize year round, there are disadvantages to keeping leaves in winter.

The main liability is water loss.  During winter, access to water can be severely limited if the ground is frozen.  If a plant is photosynthesizing, it is using water.  If it has leaves, it is loosing water (through a process called transpiration).  So, water management becomes a real issue to evergreens in the winter.

Rhodies have leathery leaves that help prevent water loss through the surface.  In extreme cold (like this morning), they roll up their leaves into cigar-shaped cylinders to reduce surface area.  (Pine needles have a small surface to volume ratio.)  Smaller surface area means less water loss.  (Think of a cup of water in a glass, and another cup in a cake pan.  More water will evaporate from the cake pan because there is more surface area.)

A second liability is that plant cells contain water.  When the water freezes it expands and the cells can burst.  Antifreeze in the sap helps protect plants from freezing cells.  Conifers have a resin in their sap that acts as antifreeze (think of turpentine).  Rhodies also produce resins in their sap that protect cells from freezing.  I don’t know for sure, but imagine these resins are what make ericaceous plant poisonous to animals.

Another liability for evergreens is snow weight on tree limbs.  Conifers confront this problem with a pyramid shape which encourages the snow to fall off (and also distributes the weight on the tips many limbs, instead of just a few).  Rhododendrons, with their rolled-up, vertically hanging leaves, don’t provide much surface for snow to cling to.

I have spent many a cold morning perched beside cigar-leaved Rhododendrons.  Although not musical, the wind rattles the leaves like wind chimes.  It is a very characteristic sound in the winter woods.

Speaking about Pools

Speaking about vernal pools, Sally Ray, the ecologist from Western Pennsylvania Conservancy who is organizing the seasonal pool registry, will be the speaker at a joint program of the Chester Ridley Crum Watersheds Association and the Habitat Resource Network of Southeastern Pennsylvania.

The talk will be at the Jeffords Mansion in Ridley Creek State Park on Saturday, February 10 at 10:00 am. The program is free and open to the public, but advance registration is requested: 484-678-6200.

Broom Snow

Broom snow (noun): A snow so light and dry it is more easily cleared with a broom than a shovel.

We’ve had our second broom snow this week. Though it’s cold out (9 F to start) we will be holding our morning and afternoon programs at Crow’s Nest today—we’ll even be going outside. Dress warmly!

Fox Sighting

This morning I was driving the tractor in the fields to do some trail work, when I saw a red fox loping through the tall grass.  It didn’t seem too concerned by me at first, and was basically keeping parallel to the tractor.  When I crossed one of the fencerows, I could see it ahead of me, moving a bit faster, but still staying parallel.  I lost sight of it in some brush, and then it popped out and crossed the trail right in front of me and sprinted down the hill into the woods.

Its fur coat was luxurious and all light orange.  Because of the variability in furs, I have been able to identify at least four different foxes at Mariton this winter.  One of these foxes was so charcoal colored that I thought it was a gray fox, until I saw its black feet and white-tipped tail.

I have no idea if any of these were part of the litter that was raised next to a trail last spring.  Several people got to see those fox kits as they played at the den’s entrance.  It was amazing that the parents chose a location so close to a trail, but there was a good food source nearby.  It is highly unlikely that they will use the same den this spring, but I will be on the look out for denning activity around Mariton.  To read more about those fox kits click on the link http://natlands.typepad.com/from_the_field_mariton/2006/04/index.html and scroll to April 20.

Christmas Tree Recycling Project

ChipperEvery year the Gwynedd Wildlife Preserve collects Christmas tree’s in the neighborhood after the holiday season for recycling. The tree’s are are collected and chipped for mulch on the preserve. In the photo, Stewardship Assistant, Sean Quinn is running the trees through the tree chipper. Thanks to all the preserve neighbors for participating! This year we collected 42 trees. The chips will be put to good use on the preserve and there is a little less debris in the landfill.   

Winter Eagle Festival

Every winter, the skies above Cumberland County fill with Bald Eagles, Red Tailed Hawks, and other raptors on their yearly migration. It is a spectacular sight to see…especially if you’re with someone who knows what they’re looking for, and has a good spotting scope!

On Saturday, February 3, Cumberland County will be hosting a Winter Eagle Festival. Volunteers from New Jersey Audubon and Citizens United to Save the Maurice River will be set up at four different sites in or near Natural Lands Trust’s Glades Wildlife Refuge, ready to help visitors spot and identify raptors.

Between rounds of bird watching, you can stop by the Mauricetown Fire Hall to warm up, get some lunch, view the displays of local non-profits and vendors (be sure to stop by NLT’s table and say hi!), and hear speakers. Lecture times, speakers, and topics are as follows:

10am: Kathy Clark of NJENSP, "Eagle Recovery and Rehabilitation"

11am: Jason Guerard of Cape May Bird Observatory (CMBO), "How to Get Started Birdwatching"

1pm: Don Freiday of CMBO, "Owls and How to Find Them"

2pm: Pat and Clay Sutton of CMBO, "Birds and Birding at Cape May"

3pm: Pete Dunne of CMBO, "25 Things That Changed Birding"

There is an admission fee of $10 for adults and $5 for children 12 and under, payable at the door of the firehouse. For more information, call 1(856)453-2177 or 1(866)966-MORE.

We hope to see you there!

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