ES2 -- The Dendroclimatic Signal of Loblolly Pine in the Piedmont of South Carolina
Start Date
8-4-2022 10:30 AM
End Date
8-4-2022 12:15 PM
Location
URC Greatroom
Document Type
Event
Abstract
Dendroclimatology, the study of annual tree ring growth in response to climatic factors, has emerged as a powerful tool in understanding the effects of climate change on plant growth, and has been especially useful in identifying unusual cooling and warming periods in more recent Earth history. The identification of reliable indicator tree species has been a primary focus of many studies outside of the well established plants in the desert southwest, where this science first began in the early 1900's. For this study, cores were taken from loblolly pines (Pinus taeda) in two different ecological areas near Clinton, South Carolina to assess their usefulness as a dendroclimatic proxy. Before coring, basic ecological conditions, including soil type and texture, tree spacing, and canopy were gathered to assess their possible effects on tree growth. The diameter of the tree at breast height (DBH) was recorded, then cores were extracted using the Haglof Swedish Increment Boring Device. The cores were prepared following standard dendrochronological protocols. Each core was measured using the Velmex Tree Ring Measuring System (TA), which includes the UniSlide Linear Stage with one micron of resolution and the Velmex Encoder Readout (VRO) which processes the data into a format usable by the computer programs ARSTAN and COFECHA. ARSTAN produces a graph comparing the chronology of tree ring measurements by detrending and standardizing the series. COFECHA was used to assess the quality of cross dating and measurement accuracy of a series of tree rings. The data was then entered into Excel to gather basic statistics including the mean, standard deviation and variance to produce standardized numbers that could be used in correlations between tree ring growth and the Palmer Drought Severity Index (PDSI) to produce graphs that illustrated common trends. The data analyzed indicate that loblolly pine has a mixed dendroclimatic signal: during specific shorter term growth periods, the correlation between tree ring diameter and the PDSI were very high. This was especially true for loblolly pines sampled in a natural habitat, near the edge of their growth zone. However, correlations were also insignificant during extended growth periods for both the natural ecosystem and those measured in more disturbed, urban habitats. Based on the very high correlations under specific growth circumstances, loblolly pine does appear to be responsive to environmental variables and may be a candidate species for use in assessing climate change in their natural growth zones.
Keywords
Ecological Science
ES2 -- The Dendroclimatic Signal of Loblolly Pine in the Piedmont of South Carolina
URC Greatroom
Dendroclimatology, the study of annual tree ring growth in response to climatic factors, has emerged as a powerful tool in understanding the effects of climate change on plant growth, and has been especially useful in identifying unusual cooling and warming periods in more recent Earth history. The identification of reliable indicator tree species has been a primary focus of many studies outside of the well established plants in the desert southwest, where this science first began in the early 1900's. For this study, cores were taken from loblolly pines (Pinus taeda) in two different ecological areas near Clinton, South Carolina to assess their usefulness as a dendroclimatic proxy. Before coring, basic ecological conditions, including soil type and texture, tree spacing, and canopy were gathered to assess their possible effects on tree growth. The diameter of the tree at breast height (DBH) was recorded, then cores were extracted using the Haglof Swedish Increment Boring Device. The cores were prepared following standard dendrochronological protocols. Each core was measured using the Velmex Tree Ring Measuring System (TA), which includes the UniSlide Linear Stage with one micron of resolution and the Velmex Encoder Readout (VRO) which processes the data into a format usable by the computer programs ARSTAN and COFECHA. ARSTAN produces a graph comparing the chronology of tree ring measurements by detrending and standardizing the series. COFECHA was used to assess the quality of cross dating and measurement accuracy of a series of tree rings. The data was then entered into Excel to gather basic statistics including the mean, standard deviation and variance to produce standardized numbers that could be used in correlations between tree ring growth and the Palmer Drought Severity Index (PDSI) to produce graphs that illustrated common trends. The data analyzed indicate that loblolly pine has a mixed dendroclimatic signal: during specific shorter term growth periods, the correlation between tree ring diameter and the PDSI were very high. This was especially true for loblolly pines sampled in a natural habitat, near the edge of their growth zone. However, correlations were also insignificant during extended growth periods for both the natural ecosystem and those measured in more disturbed, urban habitats. Based on the very high correlations under specific growth circumstances, loblolly pine does appear to be responsive to environmental variables and may be a candidate species for use in assessing climate change in their natural growth zones.