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BOTANICAL EVALUATION OF THE GOAT ISLAND COMPLEX, NIAGARA FALLS, NEW YORK |
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SOILS The surface sediments or soil were heterogeneous on Goat Island: "the soil [on Goat Island] is variable, part rich and part sand and gravel" (Douglas, 1823). The "rich" soils were probably those not altered or eroded by the river, and were probably concentrated toward the center of Goat Island, or any of the other islands in the Goat Island group. Occasionally in the literature, no distinction is made between soil and sediment: "the flow of the lake set towards the falls and brought down from the Erie basin fluviate deposits in large amounts during the succeeding years, depositing them all along the bottom of the lake. It is of these fluviate deposits, consisting of sand, and loam (excepting a comparatively small layer of drift next to the top rock [bedrock] that the soil of Goat Island is formed" (Porter, 16 Ann Rep Comm, 1900). "A calcareous soil, enriched with an abundance of organic matter, like that of Goat Island, would necessarily be one of great fertility" (Day, 1910). "The vegetation of the island is that which might be expected to luxuriate upon a deep calcareous soil, enriched with an abundance of organic matter" (Day, quoted in Porter, 16 Ann Rep Comm, 1900). The presence of the Goat Island shell beds was not unknown to Louis Agassiz when he visited the island on his way to Lake Superior prior to 1850. "The fossils form a bed extending horizontally to the river bluffs, but not beyond; they occur in great numbers, covering the surface of the soil everywhere, and contributing to the great luxuriance of the vegetation" (Agassiz,. 1850). Agassiz also noted on his passage through New York from Massachusetts, that it was "remarkable how limestone favors not only vegetable, but also animal life." Zenkert (1934) also remarked on the soil: "remains of glacial till, enriched by deposits of humus, in places support a luxuriant vegetation on the limestone bedrock. Such an enriched area is Goat Island." Serious loss of species diversity in the island complex may have contributed to depletion of species of mycorrhizal fungi, bacteria, etc., associated with certain species of plants. Corresponding loss in soil fertility may be expected due to reduced accessibility to native nitrogen. Through the years since the establishment of the Reservation in 1885, soils and gravels have been brought to the island from the mainland for a variety of reasons, primarily for the building of roads and paths, as well as landscaping, gardening, etc. In 1988 a pile of what was labeled as "garden soil" was observed by the author in the central woods which was used as a dumping and storage area for island maintenance. Visually, one area in the northeastern section of the central woods is covered on the surface with a cindery introduced soil. Material used for fill came variously from either on (gravel pits) or off the island. Perhaps the largest importation of soil from outside the native sediments on Goat Island occurred when the eastern meadow area was covered, its native regenerating vegetation cut and burned and the native soils plowed (27 Ann Rep Comm, 1911). Originally, the soil here was some three inches deep over bedrock. The new soil came "from construction work in the city ... [and] was used to deepen the soil in many portions where bed-rock was very close to the surface..." (28 Ann Rep Comm, 1912). These soils, then, did not derive from alluvial deposits in ponds on the Reservation as had been suggested in Commission reports just prior to the treatment of the eastern meadow. Another extensive soil importation must have occurred when the low land was exposed on the south side of Goat Island, including Terrapin Point, due to lowered water levels from diversion. These areas presently support grassy lawns in contrast to the vegetation of the flats areas just to the south in the river bed which were also created due to low levels in the river. Soil modifications through time were made for a variety of reasons. A small hill once existed at the entrance to the Goat Island bridge, now the pedestrian bridge. When automobiles began to regularly use Goat Island, drivers found themselves unable to detect the approach of other vehicles because this hill obstructed their view. Since accidents occurred here, "it was decided to cut down as much of these hills, on both sides of the entrance, as would enable the drivers ... to note the approach of others ..." Removal of this hill apparently opened up "a most delightful view into the interior of the island" (27 Ann Rep Comm, 1911). Grading has always accompanied structural modifications to the islands, whether as additions or deletions, be it roads, paths, the construction or removal of buildings, etc. There is one instance (on Prospect Point) where the Commissioners graded in order "to secure the most natural appearance possible, large flat stone slabs were laid in such a manner that the joints between them are made to resemble quarry seams. From this ledge the grading has been carried unevenly to the level of the grading at the entrance to the elevator, giving the slope as far as possible the appearance of the natural rock" (26 Ann Rep Comm, 1910). The appearance of Goat Island presently is that grading now is done for the convenience of efficient lawn-mowing without consideration of natural topography. The effects of compression through trampling on the soil can be seen by observing any path. Where trampling has lead to serious degradation of the soil is in the area where visitors feed the water fowl between the First Sister and Goat Island. Here the soil is eroded and sterilized, the banks are caving into the stream channel. The exposed roots of trees and shrubs are used by visitors as convenient steps for negotiating bank. Heavy infestations of urban weeds accompany this condition. Opening up the river banks along the south shore of Goat Island not only destroys the last native wet thicket community on the Island, but soil compaction and weed infestations attend visitors walking up to the open banks across the mown lawns to look out on the river. Paths which become swathes of compacted mud on top of the north bank on Goat Island are made by visitors leaving the asphalted path to obtain views of the river. The degree of disturbance of native soil horizons associated with the extensive asphalted sidewalks, viewmobile way, road and parking lotson the surface of Goat Island was not investigated. Where trampling is most serious, because of the quality of the plant communities in jeopardy (e.g. rarity, intactness, diversity and abundance) are on the Three Sisters. A careful plan to restrict access to these islands is highly recommended. |