In forest below Mann Library sugar maple, beech, hemlock, and basswood are common. The presence of numerous very large trees attests to the age of the stand, as do the large dead trees that are still standing or decaying on the forest floor. Trees of mixed ages typically coexist in very old forests, such as this one. The forested slopes south of Beebe also have younger trees and weedy vegetation. Whenever a large tree dies naturally or is cut, it leaves a sizable light-filled gap in a forest. Saplings, seedlings, and branches of adjacent trees then grow rapidly to fill in the canopy. The young trees below Toboggan Lodge are growing in the space where there once was a long toboggan run, extending from the hilltop near Olin Chemistry Research Lab, past Toboggan Lodge (hence the name), down to Beebe Lake. Look for black gum (Nyssa sylvatica) on the upper slopes at the east end of the lake, and New Jersey tea (Ceanothus americanus) at the base of the slope at the west end.
Because the long Fall Creek corridor attracts many birds from the outlying areas to Beebe Lake, the diversity of bird species is especially high. Bird watchers may want to check out Werly Island for meadow and water Birds. The woodland trail heading east from Sackett Bridge, on the north side of Fall Creek, is also a prime birding spot.
The glacial history of the area strongly affects the present landscape at Beebe Lake. During the most recent glaciation (about 10,000 years ago), the former Fall Creek Valley was filled with gravel. Since then, Fall Creek has cut a new channel, sometimes through bedrock, occasionally through the gravel deposit that filled the old channel. Above the lake at Sackett Bridge, and below the lake at Triphammer Falls, the creek is cutting through resistant layers of rock, while Beebe Lake and the slopes surrounding it sit in a very deep, erosible gravel deposit. The rushing water of Fall Creek slows when it reaches Beebe Lake, dropping its sediment load into the lake. The present landforms at Beebe reflect the natural filling and eroding processes of the creek. Sand and gravel bars (such as Werly Island) are created when heavy gravel, the bulk of the material carried by the stream, is dropped in the slower-moving lake water. Finer sediments are carried farther into the lake. When floodwaters retreat, gravel bars, like deltas, remain at the inlet.
Successional old field
A meadow on sites cleared, plowed, and then abandoned. The ragweed type occurs on fields 1 to 3 years after last cultivation; ragweed, daisy, Queen Anne’s lace, crab grass, golden foxtail, and chickweed are common. The goldenrod subtype occurs 3 – 15 years after last cultivation. Dominant species are perennial composites: goldenrods and asters. Other herbs include timothy, orchard grass, smooth brome, bluegrasses, quackgrass, sweet vernal grass, evening primrose, old-field cinquefoil, wild strawberry, and hawkweeds. Shrubs and trees represent less than 50% cover but include gray dogwood, arrowwood, raspberries, blackberries, sumac, red maple and white pine.
Mixed oak forest
A forest dominated by oaks found on steep south and west facing slopes. Soils may have calcareous materials at depth. Dominants are red, black, and white oak, and white pine. Black oak is an indicator of this ecological community type. Pignut hickory and red maple are usually present. Flowering dogwood and choke cherry are often abundant in the understory.
Shale cliff and talus community
A community with sparse vegetation that occurs on nearly vertical exposures of shale bedrock, ledges, and talus. The talus is unstable, there is little soil. Characteristic species include blunt-lobed woodsia, rusty woodsia, hairy penstemon, herb-Robert, panic grass, Carex pensylvanica, and eastern red cedar.
Beech-maple mesic forest
A hardwood forest with sugar maple and beech co-dominant. Found on moist, well-drained soils, on north and east facing slopes, and on gently sloping hilltops of any aspect, this ecological community type rarely occurs in ravines. Common associates are basswood, American elm, white ash, yellow birch, hop hornbeam, and red maple. Characteristic species in the sub-canopy are musclewood, striped maple, witch hazel, hobblebush, and alternate-leaved dogwood. There typically are few herbs and shrubs, but tree seedlings may be abundant. There are many spring ephemerals.
Hemlock-northern hardwood forest
A forest that typically occurs on lower slopes of ravines, on cool, mid-elevation slopes, and at the edges of drainage divide swamps. Hemlock is a co-dominant species with one to three others: beech, sugar maple, red maple, black cherry, white pine, yellow birch, black birch, red oak, and basswood. Shrubs have low abundance, but striped maple may be present. Herbs characteristic of northern and montane areas are common.
A forest usually found on hilltops and south to west facing slopes. Soils are acidic and well to moderately well drained, but usually have restricted rooting depth due to fragipan or bedrock. Beech, pine, or aspen may be among the dominant trees and trees of cool microclimates such as birch, hemlock, and striped and mountain maples are abundant in this ecological community type. Shrubs and herbs are abundant and moderately diverse.
The aquatic community of a stream that has a well-defined pattern of alternating pool, riffle, and run sections. Waterfalls and springs may be present. Typical aquatic macrophytes include waterweed and pondweeds. Persistent emergent vegetation is lacking.