Natural Areas

Management and Demonstration Areas
Natural Vegetation

The Arboretum includes tracts of land which are not dedicated to specific plant collections, but rather are preserved as natural or managed areas. These areas offer a rare look at some of the region's habitats of native plants and animals.

Two tracts, totaling about 200 acres, are dedicated as Natural Areas. The Oak and Hemlock forested Bolleswood tract is located west of the Arboretum Pond, and the rocky, wooded, 40-acre Mamacoke Island in the Thames River is attached to the mainland by a small tidal salt marsh. Arboretum policy calls for no manipulation other than the maintenance of trails, so these areas remain as undisturbed by human activity as possible. A brief description of the natural vegetation can be found later in this document. Natural Areas serve a number of significant functions and are an integral part of the Arboretum's identity and mission.

• Scientifically valuable, natural areas are the "controls," the "standards" or "common denominators" by which serious land management programs can be judged and evaluated. They preserve samples of vegetation types, and serve as examples of processes of natural change and development over time. The Bolleswood Natural Area is a site of long term vegetation and breeding bird surveys begun in the early 1950s and still in progress. Similar long-term studies are in progress on the Mamacoke tidal marshes.
• Educationally valuable, natural areas are "outdoor museums" for the exhibition of the plant, animal and mineral worlds. They should be treated with the same care and consideration as historical monuments or exhibits in museum halls. Both Arboretum natural areas are important components of the Biology Program of the College..
• Culturally valuable, natural areas are assuming more and more worth in a crowded world where space and privacy are becoming rare and cherished commodities. Both students and visitors appreciate the solitude and natural beauty found in these areas.

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Naturalistic Landscaping

Two formerly thicket-choked areas have been converted into beautiful natural landscapes by selective clearing of less desirable, competitive vegetation. Attractive native shrubs, small trees and wildflowers have been revealed and encouraged by this process, aided by the addition of a few planted specimens. These sites serve as demonstrations for home and commercial landscaping. One area is located at the rear of the Outdoor Theater, the other on the Katharine Matthies tract north of Benham Avenue.

Utility Right-of-Way Vegetation Management

The demonstration electric power line right-of-way, crossing the southwest corner of the Arboretum, has been continuously managed by the scientific and commercial use of herbicides for over 40 years. Tall trees which would grow and interfere with the power lines are selectively removed while the numerous wild shrubs, small trees, vines and wildflowers are unharmed. Such relatively stable mosaics of shrub-dominated plant communities have great conservation value. As a result of the Arboretum's research, this approach has been adopted as the goal of sound commercial right-of-way management by many utility companies.

A Controlled Forest Burn Plot in the Matthies Tract:

Prescribed Burning Research Areas

In 1967 the Arboretum initiated controlled burning research with support from the National Science Foundation. Selected post-agricultural fields and forest plots are being subjected to periodic burning to evaluate the effects of fire on these ecosystems.

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The Connecticut College Arboretum is located in southeastern Connecticut, about 5 miles inland from Long Island Sound. Recent glaciation (about 26,000 years ago) has greatly affected the landscape in this area. Our rocky soil, glacial eratics (large boulders), the Connecticut coastline, and our numerous wetlands are all direct results of this glaciation. The glacier scoured our hill tops and deposited till in our valleys. The Thames River, beside which we are situated, also has glacial origins. Bedrock geology is dominated by granites, schists, and gneisses.

There is considerable diversity in plant communities within the Arboretum. Our forests are part of the central hardwoods vegetation zone. Crest sites are dominated by Chestnut Oak (Quercus prinus), and Huckleberry (Gaylussacia baccatta). Midslope forests are dominated by Oaks (Quercus velutina, Quercus alba) Maples (Acer rubrum, Acer saccharum) and Black Birch (Betula lenta). Typical shrubs include Mountain Laurel (Kalmia latifolia) and Arrowwood (Viburnum dentatum var. lucidum). On lower slopes, Tuliptree (Liriodendron tulipifera), White Ash (Fraxinus amaericana) and American Beech (Fagus grandifolia) are common.

Within the Arboretum there are many wetland types, including forested wetlands, bogs and tidal marshes. Red Maple (Acer rubrum) is the dominant tree in freshwater swamps, with Sweet pepperbush (Clethra alnifolia) and Spicebush (Lindera benzoin) the most typical shrubs. Skunk cabbage (Symplocarpus foetidus), Marsh Marigold (Caltha palustris), and Pitcherplant (Sarracenia purpurea) can also be found in these areas.

The Arboretum also contains a tidal Salt Marsh. Mamacoke Marsh, situated on the Thames river, is one of the few unditched marshes left in Connecticut. Tidal marshes are incredibly productive systems both in terms of vegetation, and fauna, and act as a nursery for large numbers of marine organisms. The vegetation often occurs in bands corresponding to small differences in elevation above the mean high tide. On Mamacoke, distinct belts of Smooth Cordgrass (Spartina alterniflora), Salt Meadow Cordgrass (Spartina patens), Marsh Elder (Iva frutescens), and Switchgrass (Panicum virgatum) can be seen clearly.

In studying the ecology of an area, past human history is a crucial factor. Prior to colonial settlement, fires intentionally set by Native Americans were common. This opened the understory, making travel easier, and the re-sprouting plants provided forage for game animals. This fire tolerant forest was dominated by Oak (Quercus spp.), Hickory (Carya spp.), and Chestnut (Castanea dentata). With colonial settlement, came cultural fire suppression. This has lead to a significant increase in the forest understory as well as an increase in fire sensitive trees such as Birches (Betula spp) and Hemlocks (Tsuga canadensis). The colonial era also saw the cutting of over 80% of the eastern forest. White Pines (Pinus strobus) were used as ships' masts, while Hickory was selected as timber for its hard, straight grain. Although incredibly rocky, this land was used for agricultural purposes, especially pasturage. In the mid to late 1800's, much of this land was abandoned in favor of frontier development. The vegetation change of these 'old fields' into the regrowth forest helped determine what species are currently present. Red Cedar (Juniperus virginiana) is a small tree not browsed by domestic animals and consequently is a very common species in abandoned pastures.

Natural disturbance also plays a crucial role in understanding the current natural vegetation. The 1938 hurricane blew down trees throughout large areas of New England, including the Arboretum. This gave way to a new round of vegetation change and produced mound and cradle topography over much of the Arboretum. In the 1930's, the chestnut blight removed Chestnut as a forest tree, and today the Hemlock Woolly Adelgid continues to defoliate and kill our native Eastern Hemlock.

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