Changes in bark properties and hydrology following prescribed fire in Pinus taeda and Quercus montana
RESEARCH ARTICLEChanges in bark properties and hydrology following prescribedfire inPinus taedaandQuercus montanaCourtney Siegert1| Anna Ilek2| Adam Wade3| Callie Schweitzer41Department of Forestry, Forest and WildlifeResearch Center, Mississippi State University,Starkville, Mississippi, USA2Department of Botany and Forest Habitats,Faculty of Forestry and Wood Technology,Poznan University of Life Sciences, Poznan,Poland3Department of Sustainable Bioproducts,Forest and Wildlife Research Center,Mississippi State University, Starkville,Mississippi, USA4Southern Research Station, US Departmentof Agriculture, Huntsville, Alabama, USACorrespondenceEmail:email@example.comFunding informationNational Science Centre, Poland; MississippiState University; National Institute of Foodand Agriculture; U.S. Department ofAgricultureAbstractIn the eastern United States, the use of prescribed fire as a silvicultural technique tomanage for desirable upland tree species is increasing in popularity. Bark physicalproperties such as thickness, density, and porosity have known associations with firetolerance among species. These physical properties simultaneously influence rainfallinterception and canopy storage and thus are of interest across a range of disciplines.Furthermore, while these characteristics are innate to a species, it is unknownwhether repeated exposure to fire facilitates physical change in bark structure andwhether these changes are consistent among species. To answer these questions,bark samples were collected from mature pine (Pinus taedaL.) and oak (Quercus mon-tanaWilld.) trees from sites across the Bankhead National Forest in Alabama, USAunder three different burn regimes: 3-year cycle, 9-year cycle, and no fire. Sampleswere analysed in the laboratory for bulk density, porosity, water storage capacity,and hygroscopicity (the amount of atmospheric water vapour absorbed by bark dur-ing non-rainfall conditions). Drying rates of saturated samples under simulated wet-ting conditions were also assessed. Oak bark had higher bulk density, lower porosity,and dried slower than pine bark. Interestingly, bark from both species had lower bulkdensity, higher porosity, greater water storage capacity, and dried faster in standsthat were burned every 3 years compared to other fire regimes (p< 0.001). In sum-mary, this study demonstrates that prescribed fire regimes in an eastern US forestalter bark structure and thus influence individual tree control on hydrological pro-cesses. The increase in bark water storage capacity, coupled with faster bark evapo-ration times may lead to less water inputs to the forest floor and drier overallconditions. Further investigation of this fire-bark-water feedback loop is necessary tounderstand the extent of these mechanisms controlling landscape-scale conditions.