Forested watershed | Adaptation Workbook

Insect pests, pathogens, and interactions with drought and other disturbances may cause damage in the near term, with the Asian longhorned beetle posing a serious threat to northern hardwood species.

Ash, hemlock, and beech have already declined on the landscape due to insect pests such as emerald ash borer, hemlock wooly adelgid, and beech bark disease. There are many invasive plant species, insect pests, and forest diseases that have negative impacts on central hardwood-pine forests, many of which are expected to increase through the direct and indirect effects of climate change.

Read more about Insect pests, pathogens, and interactions with drought and other disturbances may cause damage in the near term, with the Asian longhorned beetle posing a serious threat to northern hardwood species.

Invasive species such as buckthorn, honeysuckle, garlic mustard, and Japanese stiltgrass are expected to expand in newly formed gaps and compete with native species in northern hardwood forests.

Invasive species such as buckthorn, honeysuckle, and garlic mustard are already threats to some forests, and these species are expected to increase in abundance under climate change, particularly where forests are disturbed. Invasive species can also impair regeneration of native species and alter understory and midstory composition.

Read more about Invasive species such as buckthorn, honeysuckle, garlic mustard, and Japanese stiltgrass are expected to expand in newly formed gaps and compete with native species in northern hardwood forests.

Deer herbivory is currently limiting to seedling establishment and growth in northern hardwood forests, and deer populations are not expected to change dramatically due to climate alone.

Changes in snowfall amount and duration throughout the assessment area may change the wintertime foraging behavior for herbivores such as white-tailed deer and snowshoe hare. Where present, deer may benefit in many parts of the region as warmer winter temperatures and reduced snow depth increase access to winter forage.

Read more about Deer herbivory is currently limiting to seedling establishment and growth in northern hardwood forests, and deer populations are not expected to change dramatically due to climate alone.

Some northern hardwood species may be more likley to persist or increase through the end of the century , such as red maple, northern red oak, and tulip tree.

These species all tolerate a fairly wide range of conditions. Multiple forest impact models tend to agree that these species are more likely to increase or remain stable in suitable habitat and biomass under a mild climate scenario, but these species may fare worse under a hotter, drier future climate scenario. Red maple is not modeled to change substantially, but its current abundance, biological traits, and ability to respond to disturbance suggest that it may increase.

Read more about Some northern hardwood species may be more likley to persist or increase through the end of the century , such as red maple, northern red oak, and tulip tree.

Northern hardwoods tree species are expected to respond to climate change in different ways. Several dominant tree species are projected to decline, while other species are projected to remain stable or increase.

Multiple forest impact models tend to agree that several species are more likely to decline in suitable habitat and biomass across a range of climate scenarios by the end of the century, including American beech, eastern hemlock (which can form homogenous pockets), and eastern white pine. American basswood, black cherry, sugar maple, and sweet birch are generally projected to decline under the warmer climate scenario only. Northern red oak and tulip tree are projected to remain stable under both low and high climate scenarios.

Read more about Northern hardwoods tree species are expected to respond to climate change in different ways. Several dominant tree species are projected to decline, while other species are projected to remain stable or increase.

High levels of species richness may increase the ability of forests to adapt to climate change.

This forest community is relatively rich in tree species, which may increase the number of ways in which the ecosystem can adjust to changing conditions while maintaining important ecosystem functions. Many tree species are often present, representing a broad mix of tolerances and reproductive strategies. Positive characteristics include a relatively high number of species with broad geographic ranges, large populations, and high genetic diversity. Even as some species decline, others are well-established to fill in the new gaps on a range of sites.

Read more about High levels of species richness may increase the ability of forests to adapt to climate change.

An increase in extreme weather events is expected to accelerate gap formation and regeneration. Northern hardwoods forests typically recover slowly in response to disturbance, which may lower adaptive capacity.

A combination of severe warming and drier conditions could increase wildfire risk in the Mid-Atlantic region, but topography, fragmentation, and fire suppression are likely to limit wildfire.

Read more about An increase in extreme weather events is expected to accelerate gap formation and regeneration. Northern hardwoods forests typically recover slowly in response to disturbance, which may lower adaptive capacity.

Northern hardwood forests are widely distributed across a variety of sites, increasing adaptive capacity.

These forests are also prevalent across the region on a wide variety of soils and landforms. Not all areas are expected to be affected equally, and in general, areas that are north-facing, at higher elevations, or are farther north in the region are expected to undergo less change and may continue to support northern hardwoods in the future. In these areas, it is also possible that sites that are currently too wet or cold to support northern hardwoods may become suitable over time and be colonized by these species.

Read more about Northern hardwood forests are widely distributed across a variety of sites, increasing adaptive capacity.

Changes in soil temperature and moisture and associated changes in nutrient availability or soil processes could have substantial effects on sugar maple and other northern hardwoods species.

This forest community is sensitive to reduced soil moisture and possible drought that could occur on some sites under warmer and drier conditions.

Read more about Changes in soil temperature and moisture and associated changes in nutrient availability or soil processes could have substantial effects on sugar maple and other northern hardwoods species.

Insect pests and diseases such as beech bark disease and hemlock woolly adelgid could become more problematic in spruce-fir forests under a warmer climate.

Climate change may amplify several major stressors that are already affecting this forest system. Several pests, including beech bark disease and hemlock woolly adelgid, currently affect many forests. Studies suggest that insect pests may increase in northern forests due to increased metabolic activity in active periods and increased winter survival. Insect pests, such as the hemlock woolly adelgid, are expected to cause more frequent and severe damage under climate change. Pests such as Asian longhorned beetle may present new risks as they expand, and new pests present unknown risks.

Read more about Insect pests and diseases such as beech bark disease and hemlock woolly adelgid could become more problematic in spruce-fir forests under a warmer climate.