Forested watershed

Many riverine species in this forest type were modeled only by the Tree Atlas; thus evidence is somewhat limited regarding dominant species. Suitable habitat is projected to remain stable or increase for sycamore, river birch, black walnut, and boxelder. Silver maple is projected to decrease under low climate scenarios and increase under high climate scenarios. Hemlock and red maple were modeled by all three models.

Wildfire, currently episodic and human-caused, could increase under drier conditions, although the extent would be limited by the fragmented nature of small stream ecosystems. Mortality and damage from drought or storms may result in increased coarse woody debris, contributing to wildfire fuels.

Potential changes to the precipitation regime could intensify peak stream flow and shift the timing to earlier in the spring. Reduced precipitation in the summer and fall would result in drier conditions, increasing the potential for late-summer drought. Moisture deficits have the potential to create dry vegetation conditions late in the growing season, stressing hydrophilic seedlings and supporting wildfire conditions. Drought-stressed trees may be more susceptible to diseases such as thousand cankers and elm yellows, and insect pests such as hemlock woolly adelgid.

Episodic precipitation is likely to result in more intense storms, and subsequent flooding events. Although this ecosystem is highly dependent on disturbance and a regular influx of seeds, nutrients, and water during periodic flooding, increases in flood intensity or more frequent drought may not be tolerated by many species, especially in the early growth stages. Many riverine species in this forest type depend on high moisture availability, and are especially threatened by discrete periods of dry soil conditions.

Heavy deer browsing is also limiting seedling establishment and growth, and protection from herbivory will be critical in establishing regeneration, now and under future climate conditions.

Invasive plants such as princesstree, silktree, ailanthus, and glossy buckthorn compete directly with understory plants and native tree regeneration and these invasives are likely to take advantage of increased temperatures and disturbance.

Beech bark disease, emerald ash borer, hemlock woolly adelgid, anthracnose disease, and a variety of other pests and pathogens currently affect this ecosystem. The emerald ash borer has already reduced the white ash component in parts of the assessment area.

This system is intolerant of fire, and is characterized by long disturbance intervals. An increase in wildfire could promote transition to primarily fire-adapted species (e.g., oaks), changing the identity of this ecosystem.

Droughty conditions late in the growing season can negatively impact advance regeneration and newly established seedlings.

This forest occurs largely within the lake-effect zone of Lake Erie, where this forest’s position on glacial till floodplains, moraines, and plateaus promotes and preserves moist soil conditions, a critical feature which may help buffer the impacts of changing temperature and hydrologic regimes on mature trees.