Status of bottomland forests in the Albemarle Sound of North Carolina and Virginia, 1992 - 2012

Background/Question/Methods

Among the myriad of freshwater estuaries found along the eastern United States seaboard, the Albemarle Sound, draining from southeast Virginia into northeast North Carolina, is the largest. This 2.4 million hectare watershed contains some of the largest continuous blocks of bottomland hardwood habitat in the eastern U.S. Large-scale forest surveys, conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program, are important in assessing the status of bottomland hardwood forests across the U.S. These surveys can be used to monitor important trends in forests such as species composition, growth, harvesting, and mortality. While broad in scale, FIA data can serve as an indicator for population declines, as well as a barometer for management strategies.

Results/Conclusions

In 2012, bottomland hardwood forests covered 13% (323,700 ha) of total land area in the Sound. In trees ≥12.7 cm d.b.h., Taxodium distichum (L.) Rich. (baldcypress), Nyssa aquatic L. (water tupelo), and N. biflora Walter (swamp tupelo) were the dominant species in live-tree volume. Likewise, these species accounted for 66% of the total volume in swamps and bogs, and 33 percent of the volume in floodplains. Approximately 40% of the bottomland forests were over 60 years old. Area of bottomland forests in the Sound remained stable between 1992 and 2012. Conversely, average volume per hectare declined by nearly 10%. This is likely due to high rates of harvesting that took place between 2002 and 2007. At the genus-level, oak increased by 57%, while cypress and tupelo decreased by 14% and 16%, respectively. Due to the recession (that began in 2008), harvesting rates have declined dramatically, giving these unique forests an opportunity to recover. Our analysis of 20 years of FIA data revealed that while bottomland forests in and around the Albemarle Sound appear resilient and somewhat stable, they are not immune to the cumulative effects of human and natural disturbance.