Geographic variation in growth response of Douglas‐fir to interannual climate variability and projected climate change

• DOI: 10.1111/j.1365-2486.2010.02166.x
• Publication Date: 2010-01-05T13:26:55Z
• Authors: PEI‐YU CHEN; CEDAR WELSH; ANDREAS HAMANN
• Keywords: Dryness; Growing season; Douglas fir; Dendroclimatology

Abstract We used 179 tree ring chronologies of Douglas‐fir [ Pseudotsuga menziesii (Mirb.) Franco] from the International Tree‐Ring Data Bank to study radial growth response historical climate variability. For coastal variety Douglas‐fir, we found positive correlations width with summer precipitation and temperature preceding winter, indicating that populations was limited by dryness photosynthesis in winter contributed growth. interior variety, low high growing season temperatures Based on these relationships, chose a simple heat moisture index (growing divided current season) predict for variety. 105 or 81% samples, significant linear this index, moving correlation functions showed stable over time (1901–1980). proceeded use those relationships regional under 18 change scenarios 2020s, 2050s, 2080s unexpected results: comparable changes most southern outlying Mexico least reduction productivity. Moderate reductions were United States, strongly negative central Rocky Mountains. Growth further more pronounced than elevation populations. differences slope growth–climate relationship, propose are better adapted drought conditions could therefore contain valuable genotypes reforestation change. The results support view may impact species not just at trailing edges but throughout their range due genetic adaptation local environments.