Lowland Conifer | Adaptation Workbook

A broad range of forested wetlands with a conifer or mixed conifer-hardwood overstory. These forested wetlands typically have saturated soils, which may also be seasonally flooded. Many of these forests are associated with limestone or other calcareous substrate and have acidic and nutrient-poor soils. Soils are primarily mineral, though there may be peat development or organic muck accumulation in headwater wetlands and depressions. Various conifer species may be present based on local conditions, such as black spruce, tamarack, and eastern hemlock. Black ash, yellow birch, and red maple are common associates in many sites. High elevation sites (1200 feet) in southern Pennsylvania are cool enough to also support red spruce and balsam fir.

Climate Impact Statements

Lowland conifer forests may have limited tolerance to changes in precipitation and water tables. Prolonged flooding may exceed the tolerance of some species, and increased drought risk is also a serious threat.

Many lowland conifer tree species are expected to decline, including including balsam fir, black ash, black spruce, eastern hemlock, eastern white pine, red spruce, tamarack, and northern white-cedar. Yellow birch and red maple may also decline.

Fewer than a dozen species make up the lowland conifer community, and most are projected to decline under both climate scenarios.

Increases in temperature and altered precipitation patterns could significantly alter the hydrology of lowland conifer forests.

Insect pests and forests diseases could become more problematic in lowland conifer forests under a warmer climate.

Deer herbivory is currently limiting to seedling establishment and growth, and deer populations are not expected to change dramatically due to climate alone. However, preferred browse species may change as forest composition changes.

The projected decline of keystone conifers may threaten the identity of the lowland conifer community.

Vulnerability

High

Adaptive Capacity

Low-Moderate