Forest

Impacts to this forest community are expected to vary with proximity to salt water, and reliance on groundwater. In areas disconnected from saltwater intrusion, hardwood species are likely to persist and red maple may be more competitive on sites with reduced soil moisture. The hydrology of these areas may allow some changes in the position or size of swamps without losing the system completely, though existing infrastructure and development may restrict movement.

Warmer temperatures may result in greater evapotranspiration and increased risk of moisture deficits between precipitation events.Hot droughts, even of short duration, can result in mortality of swamp trees.

Warmer winter temperatures contribute to the northward expansion of southern pine beetles, which can result in greater than 90 percent mortality of overstory pines in infested stands.

There are many invasive plant species, insect pests, and forest diseases that have negative impacts on pine-oak barrens, many of which are expected to increase through the direct and indirect effects of climate change, particularly where forests are disturbed.

Fire suppression has contributed to the decline of pitch pine and the increase of oak in some areas. In fire prone areas, trees have characteristics adapted to frequent fire, including thick bark and serotinous cones that require fire to release the seeds. Pitch pine and scrub oak can resprout, which increases their ability to survive when fires are too frequent to permit seed regeneration. Deep roots are considered to contribute to drought and fire tolerance, although very hot droughts or very hot fires can damage roots and prevent resprouting.

Although pitch pine is expected to overcome the direct effects of climate change, it is a keystone species and the loss of pitch pine to any stressor or combination of stressors would jeopardize the identity of this low-diversity forest community.

Multiple forest impact models agree that pitch pine, blackjack oak, post oak are likely to increase during the 21st century.

Heavy precipitation drains quickly due to the sandy soils of the coastal plain, and longer dry periods between events could increase the risk of moisture stress, which can be lethal to young regeneration of pitch pine and oaks. Adjacent oak-pine-hardwood forests serve as potential seed sources for pine-oak barrens, while the sandy, droughty soils discourage encroachment of mesic hardwood trees and associated understory communities.

Oak-pine forests are relatively diverse in terms of species and ecosystem functions. These forests occur 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, particularly where past land use, land development, fragmentation, invasive species, or other factors have already impaired the system.

These forests tend to have fairly high species diversity, 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.