All natural features shall be significant in terms of age, size, composition, function, structure, history, association, location, ecological value or educational interest.

The protection of one natural feature may require the protection of another which is closely linked to it. The preservation of natural features may also be necessary to avoid such adverse conditions as flooding, erosion or hazards to private property. All vegetation is part of a botanic environment or part of an aquatic feature and shall be considered as a natural feature protected by the regulations of this District. For the purposes of this Chapter, vegetation includes all forms of plant material, including, but not limited to, trees, shrubs, vines, ferns, grasses, herbs and other plant life.

All natural features defined in this Section and further described in Appendix B of this Chapter shall be protected by the provisions of this Chapter.

(a)        Geologic features

(1)        Rock outcrop

A rock outcrop is the portion of a rock formation which appears at the surface of the earth.

(2)        Geologic deposit

A geologic deposit is a mass of material which has been placed, shaped or created by the actions of wind, water, ice, gravity, vulcanism, pressure or temperature, either alone or in combination. Such deposits are to include erratic boulders, glacial formations, mineral deposits or semi-precious stones.

(b)        Topographic features

(1)        Steep slope

(2)        Existing natural topography

Existing natural topography is the ground elevation of land.

(3)        Topsoil

Topsoil is generally the top six inches of soil containing undisturbed humus and organic matter capable of sustaining vigorous plant growth.

(c)        Aquatic features

Wetlands, including, but not limited to State and Federal, mapped or designated, freshwater or tidal wetlands:

(1)        Laminarian zone

A laminarian zone is that land under the surface of salt water from the mean low tide mark to the depth of 15 fathoms. The portion of laminarian zone to be protected by the provisions of this Special District extends to the pierhead line or to the shore line where no pierhead line has been established.

(2)        Beach

A beach is a tract of relatively flat, sandy or gravelly land, without visible vegetation, forming the shore of a large body of water.

(3)        Tidal wetland and saltwater littoral zone

A tidal wetland or saltwater littoral zone is that land which is regularly covered by tidal waters and its spray.

(4)        Swamp

A swamp is a wet woodland, the soil of which is typically waterlogged or often covered with water.

(5)        Marsh

A marsh is a wet prairie that has waterlogged soil during the growing season (from last spring frost to first fall frost) and is often covered with shallow water.

(6)        Bog

A bog is a tract of waterlogged land without natural drainage.

(7)        Meadow

A meadow is a tract of land that is waterlogged to within a few inches of the surface and may have temporary ponds during the non-growing season (between the first fall frost and first spring frost).

(8)        Creek, stream or brook

A creek, stream or brook is a free flowing fresh watercourse on soil, gravel or rock that drains a watershed.

(9)        Lake or pond

A lake or pond is a body of fresh or salt water standing year round.

(10)        Natural spring

A natural spring is a point source of water exiting from the surface of the earth or rock.

(d)        Botanic environments

(1)        Primary succession community area

A primary succession community area is a tract of land characterized by species that can tolerate extreme environmental conditions and provide initial protection for less tolerant forms of life. These species are usually annuals and herbaceous.

(2)        Secondary succession community area

A secondary succession community area is a tract of land characterized by short-lived trees and shrubs as well as grasses and herbaceous material. These species are less tolerant than primary succession community species but provide a greater diversity and range of protection from the sun, wind and rain.

(3)        Climax community area

A climax community area is a stable association of plants and animals that will perpetuate itself indefinitely with minor variation in the group of associated plants. The climax community area in New York City is the glaciated oak-chestnut association, which is part of the eastern hardwood deciduous forest.

(4)        Dune or heathland

A dune or heathland is a tract of windblown and wind- or water-shaped sandy land with such characteristic species as beach grass and beach heather.

(5)        Wild grassland

A wild grassland is an area whose vegetation is primarily of wild grass species.

The natural features defined in this Section are described in Appendix B of this Chapter.