Natural Heritage

Geology

This gorge has always been a popular destination for geology class field trips because of  a variety of interesting features.  The fossils in the strata above the streambed below the large falls are diverse, abundant and among the more interesting in the region.  In this same stretch, the streambed makes some near-right-angle bends where it follows joints (vertical cracks) in the shale bedrock.

Due to lateral compression, the Tully limestone formation is two times as thick as what was originally laid down. One layer is stacked on top of another.  This stratum forms the top of the lake cliffs and the ledge or cap rock for the grandest of several waterfalls.  And it is even more clearly revealed where a number of small streams come down the slope and over the top of the lake cliff.  As you might imagine, the soils are very calcareous.


Natural History

There are several state and local rarities associated with the lake cliffs and gorge.  Upland boneset (Eupatorium sessilifolium), a locally rare plant species that had not been seen in the Cayuga Lake drainage since the 1920’s reappeared a few years ago at the top of the lake cliffs after a treatment to clear out some invasive swallowwort plants.  The forests above the lake cliffs have a lot of hop hornbeam (Ostrya virginiana), an understory tree, and are generally quite species-rich.  This is because of the limestone influence.  Oaks, sugar maple and hickories dominate the overstory canopy.  There are a lot of spring ephemerals; especially cut-leaved toothwort (Cardamine concatenata).  Woods above the lake cliffs is the only site in the Cayuga Lake drainage for the early buttercup (Ranunculus fascicularis), though this species may no longer occur in the Edwards preserve due to competition from invasive plants such as pale swallowwort (Cynanchum rossicum).

The native bittersweet (Celastrus scandens) continues to be abundant here, even though it has been pushed out of its original niche by the invasive Asian bittersweet (Celastrus orbiculatus) throughout most of the region, and is now locally rare.  Some rare ferns, most notably the purple-stemmed cliff-brake (Pellaea atropurpurea) and rusty woodsia (Woodsia ilvensis), are found on the steep rock faces of the gorge and lake cliffs.