Radial growth rate increases in naturally-occurring ponderosa pine trees: a late 20th century CO2 fertilization effect?
- UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
- Paul A. Knapp, Professor (Creator)
- Institution
- The University of North Carolina at Greensboro (UNCG )
- Web Site: http://library.uncg.edu/
Abstract: • The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to ‘step’ increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement.
• We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman’s correlation was used to relate site stress to growth-rate changes.
• Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates.
• Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions.
Radial growth rate increases in naturally-occurring ponderosa pine trees: a late 20th century CO2 fertilization effect?
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Created on 6/27/2011
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Additional Information
- Publication
- New Phytologist 171:379-390
- Language: English
- Date: 2006
- Keywords
- CO2 fertilization, ponderosa pine (Pinus ponderosa), site harshness, drought, interior Pacific Northwest