FAR2
White-tailed deer populations may increase with warmer winters, which may hinder regeneration in this forest type. Herbivory may also limit the expansion of this forest type into new areas.
These forests are also prevalent across the region on a wide variety of soils and landforms. In general, areas that are north-facing, at higher elevations, or are farther north in the region are expected to undergo less change compared to forests in warmer, drier, or more southerly locations.
Fire is the dominant natural disturbance in this system. Fire suppression has created denser forests in many locations, and increases in fire occurrence would generally be expected to favor pitch pine over more mesic oak and hardwood species that encroach in the absence of fire. However, it is unclear how human response to increased fire risk from climate change may alter future forest fire conditions.
Warmer temperatures are generally not expected to have major effects on this community because it is at the northern extent of its range in the region and occurs on particularly warm and dry sites. It is uncertain how climate change would affect the low-lying frost pockets common in this forest type, which generally favor cold-hardy scrub oak. Over the long-term, substantially warmer temperatures could reduce the occurrence of these unique microclimates.
Insect pests and diseases affecting this forest type, such as red pine shoot blight, may become more damaging under a warmer climate. Additionally, species such as southern pine beetle have been observed expanding northward, and these movements are expected to continue due to higher temperatures.
Considering the range of possible climate futures, scrub oak is projected to have little change in future habitat and pitch pine habitat may increase slightly. Likewise, other oak species that are minor components of this forest system are also generally expected to have similar or increased habitat and growth in the future. . Because these species are present on dry, low-nutrient sites, they may not face substantial competition from other species.
These forests tend to be dominated by two species: pitch pine and scrub oak. Forests with lower species diversity may be more vulnerable where one or a few species are particularly affected by changes in climate.
This forest type is often found in areas that have a high degree of past or current human disturbance, and fragmentation, invasive species, or other threats that can reduce the adaptive capacity of particular locations. Many forests are located in fragmented landscapes. A history of fire suppression and reduced light reaching the forest floor has facilitated a shift to more mesic conditions and associated hardwood species (e.g., red and sugar maple, American beech, tuliptree).
Studies suggest that insect pests may increase in northern forests due to increased metabolic activity in active periods and increased winter survival. Many insect species are limited by extremely cold temperatures, and evidence suggests that several insect species may increase in a warmer climate, including the hemlock woolly adelgid. Trees stressed by heat, drought, or disturbance are also typically more vulnerable to insect pests and diseases. Emerald ash borer and Dutch elm disease are expected to continue to limit ash and elm species.
There are many invasive plant species, insect pests, and forest diseases that have negative impacts on lowland and riparian hardwoods, many of which are expected to increase through the direct and indirect effects of climate change. Invasive species such as Japanese stiltgrass and buckthorn are existing threats to these forests, and invasive species are expected to increase in abundance under climate change, particularly where forests are disturbed.
