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facilities renewal master plan - National Zoo - Smithsonian Institution

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FACILITIES MASTER PLAN ENVIRONMENTAL ASSESSMENT<br />

A.2 Vegetation<br />

The <strong>National</strong> <strong>Zoo</strong>’s Rock Creek site is surrounded by an urban environment, with varying<br />

stages of vegetative succession within the park itself. Vegetation throughout the park<br />

ranges from areas in an herbaceous stage, to maturing and mature forested areas.<br />

Undeveloped areas of the <strong>National</strong> <strong>Zoo</strong> consist primarily of deciduous forest. A tree<br />

survey was conducted on the grounds in 2003 in order to categorize the value of the trees<br />

for insurance purposes. Over 60 tree species were identified during this survey, including<br />

a mixture of native and introduced species such as boxelder (Acer negundo), American<br />

holly (Ilex opaca) and tree of heaven (Ailanthus altissima). Numerous native and nonnative<br />

<strong>plan</strong>ts are also present throughout the park within horticultural collections and<br />

exhibit <strong>plan</strong>tings, and are important to the health and welfare of many of the animals on<br />

exhibit. Non-native <strong>plan</strong>ts are considered invasive if they have no natural controls, and<br />

have the ability to out-compete or displace native <strong>plan</strong>ts. Such species occurring within<br />

the park include English ivy (Hedera helix), running bamboos (Phyllostachys, Bambusa,<br />

Pseudosasa) and common reed (Phragmites australis).<br />

Impacts to Vegetation<br />

No-Action Alternative<br />

Under the No-Action Alternative, additional exhibit <strong>plan</strong>ning outside of the on-going<br />

Elephant Trails project would continue on a site-by-site basis. Other small scale site<br />

improvements would continue for site improvements, building rehabilitation, and<br />

<strong>facilities</strong> updates related to safety, health, and maintenance. Minor impacts to vegetation<br />

would occur to existing landscaped areas and no new construction is anticipated in<br />

undisturbed and natural areas of the <strong>National</strong> <strong>Zoo</strong> property. With landscaping of new<br />

exhibits or habitats, vegetation would be replaced. Under the No-Action Alternative,<br />

negligible adverse impacts to vegetation would occur because small scale site<br />

improvements related to safety, health and maintenance could impact existing<br />

landscaping.<br />

Alternative A<br />

Under Alternative A, <strong>facilities</strong> improvements would result in construction activities<br />

requiring land disturbance that would impact vegetation. Construction occurring within<br />

previously disturbed and developed land areas of the <strong>National</strong> <strong>Zoo</strong> would impact current<br />

landscaping, which would be replaced in the context of the new <strong>facilities</strong> and exhibits.<br />

Some undeveloped forested areas would also be cleared under Alternative A with the<br />

construction of the aerial tram. Impacts associated with each activity would include<br />

minor to moderate, site-specific losses to trees and shrubs during construction and<br />

revitalization of <strong>facilities</strong> and exhibits. Similar to past activities at the <strong>National</strong> <strong>Zoo</strong>, SI<br />

would use tree protection measures to the extent practicable to save larger tree specimens<br />

that are indigenous to Rock Creek and the surrounding area.<br />

Activities most likely to impact park vegetation under Alternative A include:<br />

Reclamation of Parking Lots A, B and the Bus Lot for the creation of new, large<br />

multi-species exhibit areas;<br />

Revitalization of the Connecticut Avenue visitor entrance;<br />

SMITHSONIAN INSTITUTION – NATIONAL ZOOLOGICAL PARK 46 | P a g e

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