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Hillock Woods Site Assessment

November 25, 2009

Prepared by:
Jonathan Kays
Principal Agent, University of Maryland Extension
Maryland Licensed Professional Forester #662

I visited the Hillock Woods site with Dr. Marla McIntosh and two other students on November 19, 2009. I returned to the site alone on November 24, 2009 and spent about 2 hours walking the entire site. I was asked to make an assessment of the forestry, wildlife, and biodiversity considerations as well as the research and teaching value of the site, given my background as a professional forester and extension forester for the University of Maryland Extension. I am located at the Western Maryland Research & Education Center in Keedysville, MD (near Hagerstown).

My understanding regarding the 22-acre site is that that about 9-acres of the eastern portion of forest is to be cleared and used for parking lots and university service buildings.

Soil Description (excerpts from USDA Prince George’s County Soil Survey)

The site consists of fairly infertile soils with some fairly strong slopes that are natural sand and gravel deposits. Classified as Sandy and clayey land, sloping (ScC) on the soil survey, the soil material consists of very old deposits of clay covered by a mantle of sand, gravel and some fine clay. The soils have low-moisture holding capacity and are not productive, even under good management. The soils have poor stability and they are a high erosion hazard. The soil material, when disturbed has poor stability, which limits them for most uses and makes them dangerous for some uses. They may be squeezed out from under buildings foundations. Occasionally, property is damaged when fills consisting of these materials collapse.

The large amount of sand and gravel and poor moisture holding capacity of the soils results in low levels of natural fertility. The soils are woodland capability class 14, which is well adapted to species such as Virginia pine or oak species. A soil pit with instrumentation is located on the edge of the forest area.

Forest Type

The overall forest area is an example of a mid-succession hardwood forest that is remarkably free of invasive species, which are common to fragmented forests in developed areas. Virginia pine is an early succession, short-lived species that dominated much of the higher and drier sites found at the eastern part of this forest area. There is evidence of deer browsing of the understory vegetation, which causes a visible browse line to about 5 feet. The forest area is seen as developed forest on the 1963 aerial photographs, so it has likely been forest for at least 70-90 years or more, an age confirmed by taking a core from one of the mature white oaks.

The major species now present are white oak, American beech, and black oak, with lesser amounts of red oak, and American holly. Average diameter of the trees is around 12-19 inches in diameter at breast height (4.5 feet from the ground). Virginia pine trees 12-14 inches in diameter were a dominant part of the eastern half of this property along with the white oak, but almost all of the Virginia pine trees were blown down by a tornado in September 2001. This had the effect of releasing the sturdier 10-13” diameter white oak trees which have now become the dominant canopy, along with understory beech trees that are now growing into the canopy. The understory in these areas is dense mountain laurel that grows to 10 foot tall. The damaged Virginia pine trees where cut to the ground and into small lengths after the tornado. They form piles, making walking through some areas difficult. Many Virginia pine and white oak trees were blown over and large soil mounds heaved up.

The higher elevation potion of the woods at the eastern end of the property was hardest hit by the tornado. The entire canopy of trees on many acres were either sheared, blown over and uprooted, or stripped of their branches and now dead snags. This area is now densely-covered with small diameter oak stems (1-2” diameter), lowbush blueberry, devil’s walking stick, and some beech.

In general, there are four main identifiable areas or stands on this property:

1. Mature hardwood area composed of white oak, black oak, and smaller beech trees. These areas were relatively untouched by the tornado and contained few if any Virginia pine. This area makes up most of the northwest portion of the property that borders Rt. 193.
2. Hardwood – Virginia pine area that was hit by the tornado. The Virginia pine was blown down and eliminated from the canopy, leaving the white oak (if present) to take over the canopy along with some other hardwoods. There is a dense understory of mountain laurel. This area makes up the eastern portion of the property surrounding the high knoll.
3. Newly regenerated area that was completely leveled by the tornado, simulating a clearcut harvest. Dense oak regeneration, blueberry, devil’s walking stick and beech are found in this area. This area is found on high knoll and to the east and southeast of that location.
4. Old field forest – the small area north of the Chesapeake Building parking lot and west of Paint Branch Drive is an old field that has reverted to forest cover. There are a few large pin oak, but most of the vegetation is 1-2” diameter sweetgum, silver maple, yellow-poplar, and willow. There are many invasive species in this area.

The ecological values of the forest area are summarized as follows:

• Example of a mid-succession hardwood forest on a poor quality site susceptible to erosion. Early succession Virginia pine trees were removed by the tornado leaving the site dominated by later succession white oak trees.
• Large contiguous block of intact forest in an urban area that is relatively undisturbed and isolated and not dominated by invasive species. These areas are rare.
• Provides an outside laboratory to contrast changes in forest composition, development, and wildlife habitat between a relatively undisturbed forest and one experiencing a major disturbance due to a tornado.
• The habitat diversity created by the adjacent forest types with minimal edge provides unique opportunities for wildlife viewing and instruction.

The impacts to the remaining forest if the eastern portion is developed are as follows:

• The size of contiguous forest block will be greatly reduced, creating a hard edge with close proximity to developed facilities with lots of vehicular traffic. Edge is where different vegetation communities come together. This will impact the forest bird species that now use the area by allowing easier access by more aggressive species found in fragmented landscapes.
• The close proximity of the proposed motor pool and maintenance sheds to the remaining forest area will allow easy access of seeds and vegetation brought in by vehicles. They will likely find their way by into the remaining forest area and increase the abundance of invasive species.
• The present forest area is large and remote enough, and contains the diversity needed for high quality ecological instruction. It is within walking distance of the major academic buildings and has the potential for further development as an interpreted on-campus classroom and ecological area for research and teaching. The forest area is already used by some university instructors and their students.

2009 Student Sustainability Council at the University of Maryland, College Park.