Sycamore Island

Background

Allegheny Land Trust acquired Sycamore Island in January 2008. Before the island was protected by ALT, the island had periodic interludes of recognition and appreciation by humans as a natural refuge. In 1936, both Sycamore Island and Nine Mile Island were leased from the Pennsylvania Railroad by the Audubon Society of Western Pennsylvania, making these islands the first bird sanctuaries in the Pittsburgh region. The Harbor Isle Boat Club was in existence on the island during the late 1960s, but were later abandoned leaving behind several significant features; including a barge that remains embedded in the sand at the island’s southern tip, a partially installed swimming pool, docking platform, and a series of offshore pilings in the back channel.

During the last century, development and industrialization of the watershed contributed to changes in the island’s configuration and topography, due in part to dredge spoiling and increased sedimentation from development. Because of these changes and the island’s position in the river, its area has more than doubled from just over 6 acres in 1809 to over 14 acres today. More recent impacts to the Island’s ecology include the effects of invasive species and climate change. All of these stressors must be considered and addressed in long-term management efforts.

The Pennsylvania Natural Diversity Inventory (PNDI) classifies floodplain forest as imperiled in the state, and Sycamore Island has a ranking of “high significance” within the Allegheny River Biological Diversity Area (BDA) Natural Heritage Area. The ecological and cultural significance of Sycamore Island is well known. Previous studies such as the 3 Rivers 2nd Nature Report conducted by Carnegie Mellon University characterizing riverbank vegetation in the Allegheny and Monongahela Rivers have described the ecological resources and conservation value of Sycamore Island (3Rivers 2nd Nature, 2002).