Rosanne D’Arrigo, Lamont-Doherty Earth Observatory, Columbia University, USANicole Davi, William Paterson University and Lamont-Doherty Earth Observatory, Columbia University, USAGordon Jacoby, Lamont-Doherty Earth Observatory, Columbia University, USARob Wilson, University of St. Andrews, UK and Lamont-Doherty Earth Observatory, Columbia University, USAGreg Wiles, The College of Wooster and Lamont-Doherty Earth Observatory, Columbia University, USA

• Preface  vAcknowledgments  vii1. Introduction 11.1. Overview 11.2. Basic Tree-Ring Principles 11.3. Polar Amplification of Global Warming and Impacts on Forests 31.4. “Northern Archive” Synthesis 62. Tree-Ring Investigations at Northern Latitudes 72.1. Initial Studies 72.2. Site Selection 82.3. Tree-Ring Parameters and Processing: Ring Width and Maximum Latewood Density 93. Selected Local to Regional TRL-LDEO Northern Tree-Ring Studies 134. The Broader Context of Northern Dendroclimatic Studies 194.1. North America 194.2. Eurasia 214.3. Tree-Ring Chronology Networks 215. Temperature Reconstructions for the Northern Hemisphere 235.1. Initial Attempts 235.2. Evolution of NH Temperature Reconstructions 255.3. Reconstructed NH Temperature Trends 315.4. Standardization of NH Tree-Ring Temperature Reconstructions 336. Tree Growth Issues in the Anthropogenic Era: CO2 Fertilization and the “Divergence Problem” 376.1. CO2 Fertilization 376.2. The Divergence Problem 387. Conclusions and Future Challenges 43Glossary 51References 57Core TRL-LDEO Publications on Northern Forests 67Index 75Color plate section is located between pages 36 and 37.

“I enjoyed the short format, and would support the production of further AGU OPUS themed syntheses, but would respectfully suggest that the programme reviews the format to permit a wider scope for general themes and greater detail for more specialist topics.”  (The Holocene, 1 February 2015)

Rosanne D’Arrigo, Lamont-Doherty Earth Observatory, Columbia University, USANicole Davi, William Paterson University and Lamont-Doherty Earth Observatory, Columbia University, USAGordon Jacoby, Lamont-Doherty Earth Observatory, Columbia University, USARob Wilson, University of St. Andrews, UK and Lamont-Doherty Earth Observatory, Columbia University, USAGreg Wiles, The College of Wooster and Lamont-Doherty Earth Observatory, Columbia University, USA

• Preface  vAcknowledgments  vii1. Introduction 11.1. Overview 11.2. Basic Tree-Ring Principles 11.3. Polar Amplification of Global Warming and Impacts on Forests 31.4. “Northern Archive” Synthesis 62. Tree-Ring Investigations at Northern Latitudes 72.1. Initial Studies 72.2. Site Selection 82.3. Tree-Ring Parameters and Processing: Ring Width and Maximum Latewood Density 93. Selected Local to Regional TRL-LDEO Northern Tree-Ring Studies 134. The Broader Context of Northern Dendroclimatic Studies 194.1. North America 194.2. Eurasia 214.3. Tree-Ring Chronology Networks 215. Temperature Reconstructions for the Northern Hemisphere 235.1. Initial Attempts 235.2. Evolution of NH Temperature Reconstructions 255.3. Reconstructed NH Temperature Trends 315.4. Standardization of NH Tree-Ring Temperature Reconstructions 336. Tree Growth Issues in the Anthropogenic Era: CO2 Fertilization and the “Divergence Problem” 376.1. CO2 Fertilization 376.2. The Divergence Problem 387. Conclusions and Future Challenges 43Glossary 51References 57Core TRL-LDEO Publications on Northern Forests 67Index 75Color plate section is located between pages 36 and 37.

“I enjoyed the short format, and would support the production of further AGU OPUS themed syntheses, but would respectfully suggest that the programme reviews the format to permit a wider scope for general themes and greater detail for more specialist topics.”  (The Holocene, 1 February 2015)

Rosanne D’Arrigo, Lamont-Doherty Earth Observatory, Columbia University, USANicole Davi, William Paterson University and Lamont-Doherty Earth Observatory, Columbia University, USAGordon Jacoby, Lamont-Doherty Earth Observatory, Columbia University, USARob Wilson, University of St. Andrews, UK and Lamont-Doherty Earth Observatory, Columbia University, USAGreg Wiles, The College of Wooster and Lamont-Doherty Earth Observatory, Columbia University, USA

• Preface  vAcknowledgments  vii1. Introduction 11.1. Overview 11.2. Basic Tree-Ring Principles 11.3. Polar Amplification of Global Warming and Impacts on Forests 31.4. “Northern Archive” Synthesis 62. Tree-Ring Investigations at Northern Latitudes 72.1. Initial Studies 72.2. Site Selection 82.3. Tree-Ring Parameters and Processing: Ring Width and Maximum Latewood Density 93. Selected Local to Regional TRL-LDEO Northern Tree-Ring Studies 134. The Broader Context of Northern Dendroclimatic Studies 194.1. North America 194.2. Eurasia 214.3. Tree-Ring Chronology Networks 215. Temperature Reconstructions for the Northern Hemisphere 235.1. Initial Attempts 235.2. Evolution of NH Temperature Reconstructions 255.3. Reconstructed NH Temperature Trends 315.4. Standardization of NH Tree-Ring Temperature Reconstructions 336. Tree Growth Issues in the Anthropogenic Era: CO2 Fertilization and the “Divergence Problem” 376.1. CO2 Fertilization 376.2. The Divergence Problem 387. Conclusions and Future Challenges 43Glossary 51References 57Core TRL-LDEO Publications on Northern Forests 67Index 75Color plate section is located between pages 36 and 37.

“I enjoyed the short format, and would support the production of further AGU OPUS themed syntheses, but would respectfully suggest that the programme reviews the format to permit a wider scope for general themes and greater detail for more specialist topics.”  (The Holocene, 1 February 2015)