Monday, July 30, 2012

Atop the Kittatinny Ridge

On Monday morning, I was able to get out along the Kittatinny Ridge above Palmerton, PA with a group of interns working with the Superfund restoration projects at that site. We were on the mountain looking at two recently burned areas on the ridgetop. This piece of the ridge, once barren due to heavy pollution from a nearby zinc smelter, has been revegetated with native grasses. Recent fires burned small portions of the area, and we were interested in how the ecosystem changed as a result. Although the fires here were not controlled burns, they seemed to have helped the habitat by controlling some of the shrub and tree species that have started to establish populations within the grassland.

While we were up there, a thick layer of fog sat over us, drenching us as we hiked through damp vegetation. The view from here would have been spectacular if the sun had been shining! 

As we were interested in the effects the fire had on the plant communities, we compared the burned areas to habitats that had not been burned. Other than the apparent effect on shrubs and trees as I mentioned above, the fire seemed to have little negative effect on the various grass species.

An example of the grassland habitat on the ridgetop. Dominant grass species include big bluestem, deertongue grass, Canada wild rye, and common hairgrass.

One of the unique plants that grows on top of the mountain near the Superfund site is thrift (Armeria maritima), a small plant with pink flowers the grow up from the ground-level rosette of leaves. This unusual flower is not native and was likely brought in as an early revegetation attempt. We saw large patches of this plant near the burn area, although very little actually grew within the burn site, suggesting that it cannot tolerate fire. In the areas where it was growing, I noted a number of Common Roadside-Skippers (which, despite the name, are uncommon in this region) nectaring on the thrift.

Studies from Europe have shown that thrift, or sea-thrift as it is sometimes known, can tolerate soils with high levels of metals1. This is not surprising, as the soils where the thrift grows near Palmerton are heavily contaminated with zinc, cadmium, and lead.

The second burn site was closer to the Lehigh Gap along a trail known as the Winter Trail to hikers. The habitat here contained many woody plants (especially pitch pine, sassafras, and scrub oak) and the grass present was almost entirely hairgrass with a small amount of big bluestem mixed in. Notice how the fire thinned out, but did not kill the hairgrass. This hairgrass is a species that started growing in this contaminated area on its own; it was not part of the grassland revegetation projects.

After we visited the burn sites, we stopped at a spot about halfway between Lehigh Gap and Little Gap. The combination of the muddy puddle, the grassy landscape, and scraggly pitch pines in this area created a very unique habitat. A few of the bird species at this spot were unusual too. While we were here for a few minutes, I heard several Dark-eyed Juncos singing nearby. This is a species that is very uncommon in eastern Pennsylvania during the summer. Although juncos are extremely abundant during the winter months, most migrate much farther north to breed. However, this unusual habitat at a high elevation provides the necessary elements for juncos to raise young.

Someday, I'd like to go back up to this spot to find out what other unusual plants and animals are living in this strange habitat. It is relatively inaccessible locations like this were unusual things can be found, whether it be an out-of-place breeding bird or a rare plant!

1Brewin, L.E., A. Mehra, P.T. Lynch, and M.E. Farago. "Mechanisms of copper tolerance by Armeria maritima in Dolfrwyong Bog, north Wales—initial studies". Environ Geochem Health 25 (1): 147–56.

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