Imperiled Ecosystems in a Shifting Climate
2016 Atlantic White Cedar Symposium
May 24-26, 2016

Hotel 1620, 180 Water St., Plymouth, MA

Analysis of early growth in Atlantic White Cedar as a predictor of hydrologic conditions in Southeastern Virginia peatlands

C. G. Mirda, christina.mirda.13@cnu.edu

J. Slater, julie.m.slater@gmail.com

R. B. Atkinson, atkinson@cnu.edu

Department of Organismal and Environmental Biology, Christopher Newport University

Abstract

Early growth of Atlantic White Cedar [AWC, Chamaecyparis thyoides (L.) B.S.P.] is routinely measured during stand reestablishment and several studies have concurrently evaluated hydrologic conditions.  While survival is most strongly related to soil saturation, various indicators of soil saturation are better predictors of stem diameter growth of AWC. In this study, we assist efforts to reverse that model and characterize historic soil saturation levels to 1919 in the Great Dismal Swamp National Wildlife Refuge (GDSNWR) based on two indicators of growth: ring width and basal area increments (BAI) of newly planted AWC which we then contrast with two older age classes.  A sampling strategy-derived age differential occurs because planted seedlings and cuttings are typically sampled at ground level whereas our previous dendroecological investigations cored trees at breast height, which may coincide with 4 to 5 year old rings.  Mean annual ring width for newly-planted AWC in GDSNWR (2.75 mm) was greater than widths from the last 10 years of cored tree age (1.82 mm) and was greater than the first 10 years (2.08 mm) for 39% of trees; and there was no difference in ring widths for 40% of cored trees.  When these metrics were converted to BAI, results indicated that early growth rates (28-75 mm^2) were similar to subsequent rates during the first 10 years of cored samples (51.4 to 256.1 mm^2), whereas rates stabilized by 1968, and after 50 years the mean annual BAI was 2337.3 mm^2 resulting in a sigmoidal growth curve. 

Keywords: peatlands, hydrology, indicator species, Great Dismal Swamp National Wildlife Refuge

Biography: Christina Mirda is an undergraduate researcher for Rob Atkinson's lab at Christopher Newport University in Newport News, VA. Her poster summarizes the results of 17 studies of early Atlantic white cedar growth and provides recommendations for hydrologic management in planting.