BOTANICAL EVALUATION OF THE GOAT ISLAND COMPLEX, NIAGARA FALLS, NEW YORK
PART I: PHYSICAL FEATURES
THE PHYSICAL SETTING
The islands lie within a thirty-three mile strait called the Niagara River, forming the boundary between the United States and Canada. The River begins at Buffalo, New York, on Lake Erie, and ends at Youngstown on Lake Ontario (Tesmer, 1981). The islands lie roughly twenty-two miles north of Buffalo. The western boundary of Goat and Luna Islands is continuous with the brinks of the cataracts of the Niagara River at the cities of Niagara Falls, New York, and that of Niagara Falls, Ontario, which cataracts are collectively called Niagara Falls. After passing the islands and the cataract, the Niagara River proceeds in a northerly direction some 250 feet below the level of the surrounding land in a seven mile gorge whose outlet lies at Lewiston, New York and Queenston, Ontario (Tesmer, 1981). Here the Niagara River continues across the Lake Ontario lake plain north until discharging into Lake Ontario.
Goat Island is in the shape of an ellipse with its long axis oriented in an east-west direction. The river channel at the location of the Island also runs east-west, bending westward upstream at the northern tip of Grand Island, New York, and Navy Island, Ontario, and turning roughly north after it passes the Goat Island complex and descends over its cataracts. The islands in the complex bear the brunt of the river current at their eastern ends, and the force of the prevailing winds at their west, southwestern end.
In 1900, Goat Island was reported to be one half mile long, and a quarter of a mile in width. The length of Goat Island indicated in a section across it in an east to west orientation was 2,500 feet (Lyell, 1845). There were 16 additional islands then "varying in size from an average of 400 feet to 10 feet in diameter" (16 Ann Rep Comm, 1900). In 1901 there were 62.46 acres of flat land and 11.44 of slope, for a total of 73.90 acres for the total island acreage in the Reservation (from a survey made for the Commissioners, 17 Ann Rep Comm, 1901). Mention will be made here of the four islands on the southeastern margin of Goat Island. The First, Second and Third Sister Islands are wooded islets of limited extent, each south of the other as they extend into the Horseshoe or Canadian channel of the Niagara River, and each separated from the other by small channels of water. The fourth island, Brother Island, is just west, or downstream, of the Third Sister, separated by what appears to be a joint in the dolomite bedrock.
The surface area of Goat Island has been increased since acquisition by the State of New York in the 1880's. Lowered water levels have made more land in the complex by increased river bed exposure at the particularly at the southwestern corner of Goat Island since 1954, and by exposure all along the southern margin of Goat Island of small "flats" areas, relatively recently vegetated mostly by shrubby willow species. Additions or reductions to the number of islands in the American channel was not investigated for the present survey. Access to these islands was not provided. A significant area of "made land" extending the area of Goat Island was created on the eastern extremity of Goat Island in 1959-60 (The American Falls International Board, 1971).
Elevation at the west end of Goat Island is 550 feet above sea level: at Terrapin Point near the water's edge at the Horseshoe Falls it is 511 feet. The Three Sisters Islands are at 550 feet. Elevation drops in the Canadian channel of the river from 550 feet at the Sisters to 511 feet at Terrapin Point: elevation of the river bed at the brink of the Horseshoe Falls is one foot higher than at Terrapin Point: 510 feet, and there is a forty foot drop in elevation along the south side of Goat Island with corresponding increase in the force of the current. In the channel of the American Falls, Green Island stands at 540 feet and Bird at 520 (statistics from Ontario Hydro Information in Tiplin, 1988).
At Goat Island's eastern end the water is only a few feet below ground-surface level. Its western end is composed of a 176 to 184 foot escarpment (NREP, 1972), forming part of the wall of the gorge of the lower river, with a forested talus accumulation at its base, presenting a 2500-foot shoreline to the lower river, flowing in a northerly direction. The island presents bluffs of various soil types on the north and southern boundaries, becoming deeper toward the western boundary and presenting distinct northern and southern exposures.
Soil characteristics, amount of sunlight, exposure or protection from prevailing winds, and availability of moisture are some of the features of the physical environment which influence the development of vegetation in any area. The following are some of the physical characteristics of the study area which contribute to some understanding of the character of the vegetation in the Goat Island complex.