Legacy FAR1 strategy/approaches.
There are many invasive plant species, insect pests, and forest diseases that have negative impacts on tidal swamp forests, many of which are expected to increase through the direct and indirect effects of climate change.
Multiple forest impact models tend to agree that many tidal swamp species are likely to maintain or increase in suitable habitat and biomass during the 21st century. Green ash species is threatened by Emerald Ash Borer and is expected to decline significantly from the borer during the next several decades.
As sea level rises, increasing salinity levels may interact with other stressors, and the salt tolerance of individual trees may factor into tree response. Of the dominant species in tidal swamp, only baldcypress and green ash are resistant to salt spray.
Rising sea levels are increasing storm surge and flooding, and this may become an even greater problem as storms become more frequent or severe.Shifting sands may alter soil characteristics, destabilize root systems, and cause erosion. Tidal forest that undergoes salinization exceeding its tolerance may be replaced by tidal marsh. However, shorelines are expected to recede as the sea level rises, resulting in the physical loss of land and habitat for this community type.
Atlantic white-cedar is a keystone species restricted to the coast and rapid changes in salinity and water depth may result in the total loss of cedar swamps. Deer use cedar swamps to avoid severe winter weather, so even low deer populations can be damaging.
Multiple forest impact models tend to agree that many swamp species are likely to maintain or increase in suitable habitat and biomass during the 21st century. Some species, such bald cypress and pin oak may increase under a range of potential change. Others such as green ash and sweetgum may persist under slightly warmed conditions, but are projected to increase under scenarios projecting hotter and drier conditions. All ash species are threatened by emerald ash borer.
Rising sea levels, combined with storm surge and erosion may drive the coastal zone inland, resulting in rapid changes in tree species’ habitat. Saltwater intrusion can kill Atlantic white-cedar forests and may damage other species depending on the intensity and duration. Increased flooding can increase runoff and discharge from farm land and concentrated animal feed lots, thus increasing nutrient loads.
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.
