Plot 4 was dominated by American Beech, which at over 30% of the plot far outnumbers any other single species in the immediate area (see Figure 3 or 6 on previous page). This is likely due to the presence of a single large White Oak, a large Sweet Gum and two large Tulip Poplars, which provide a thick canopy of leaves. American Beech prefer more shade than some other tree species, and likely benefit from this canopy. Additionally, the proximity to the Meeting of the Waters Creek provides ample water to the area, but likely also causes a large amount of erosion after rainfalls when the creek level rises near of over the bank. American Beech require a lot of water but also well-drained, aerated soil, so their abundance near the creek is no surprise.
Despite the dominance of the American Beech, this plot shows a relatively high level of diversity of deciduous trees, which indicates healthy soil conditions. The lack of incline in the plot means that erosion will be much less than that of the steep hills to west and east, reducing nutrient loss from runoff. Soils in pine-dominated areas tend to be acidic due to the high acid content of decomposing needles in the ground cover; the lack of pine trees in this area likely means the soil is not as acidic, allowing other species to thrive. With the close proximity to Manning Drive, it is surprising that the plot exhibits such healthy soil conditions, as American Beech are intolerant to pollution from urban runoff. This may be due to the Meeting of the Waters Creek, which runs at the bottom of the hill leading up to Manning Drive. This prevents road runoff from entering the soil of the plot, instead running into the creek and being carried downstream.
The age distribution of the trees in this plot (Figure 4 on previous page) show very few old trees, with most of the ages clustered around the 15-20 year range as well as a number of very young trees less than 10 years old. This may indicate that there was a disturbance around 20 years ago, after which only the Sweet Gum and White Oak survived. The area is far from pristine forest habitat, being only a few hundred meters from the busy Manning Drive. Within the Pinetum, an OWASA water main runs both above and below ground at parts. Construction on this water main could have contributed to multiple disturbance events, accounting for the clustering around 20 years and under 10 years. Indeed, OWASA financial reports document restoration work on the water main between 2006-2008, likely the reason for the large number of young trees in the plot.