Towards the extremes: A critical analysis of pointer year detection methods

Abstract To study growth responses of trees to extreme events, analyses of so-called ‘pointer years’ are often performed. Thereby, the term pointer year refers to years in which a majority of trees shows extraordinary growth responses, like very narrow (or wide) ring widths. A wide variety of methods has been used to analyze pointer years, hampering comparisons between studies. The latter illustrates that there is a strong need to harmonize pointer year detection methods. This review contributes to that by describing and comparing the main methods (and variants thereof) found in the literature for the last two decades, both in a qualitative and quantitative way. We discuss methodological considerations and provide recommendations how to proceed with pointer year detection in future. Given that the individual methods for pointer year detection were found to highlight different aspects of extraordinary growth, the one method cannot completely substitute the other. Hence, we suggest to use multiple methods in a harmonized way to get the deepest insight into the nature of pointer years.

[1]  R Core Team,et al.  R: A language and environment for statistical computing. , 2014 .

[2]  Fnp,et al.  Multilingual glossary of dendrochronology : terms and difinitions in English, German, French, Spanish, Italian, Portuguese and Russian , 1995 .

[3]  B. Brzeziecki,et al.  A 350‐year tree‐ring fire record from Białowieża Primeval Forest, Poland: implications for Central European lowland fire history , 2010 .

[4]  M. Manthey,et al.  Drought matters – Declining precipitation influences growth of Fagus sylvatica L. and Quercus robur L. in north-eastern Germany , 2011 .

[5]  E. Feliksik,et al.  Tree-Ring Chronology as a Source of Information on Susceptibility of Sitka Spruce to Climatic Conditions of Pomerania (Northern Poland) , 2008 .

[6]  K. Migała,et al.  Two centuries-long dendroclimatic reconstruction based on Low Arctic Betula pubescens from Tromsø Region, Northern Norway , 2016 .

[7]  F. Serre-Bachet,et al.  Identification, presentation and interpretation of event years and pointer years in dendrochronology. , 1990 .

[8]  T. Sanders,et al.  Species-specific climate response of oaks (Quercus spp.) under identical environmental conditions , 2014 .

[9]  T. Kolář,et al.  Extreme Radial Growth Reaction of Norway Spruce Along An Altitudinal Gradient in the Šumava Mountains , 2009 .

[10]  D. Elferts Scots pine pointer-years in northwestern Latvia and their relationship with climatic factors , 2007 .

[11]  T. Levanič,et al.  Climatic effects on birch (Betula pubescens Ehrh.) growth in Fnjoskadalur valley, northern Iceland , 2008 .

[12]  Werner Kofler,et al.  Climate-tree-growth relationships of Scots pine stands (Pinus sylvestris L.) exposed to soil dryness , 1998, Trees.

[13]  N. Breda,et al.  Forest tree responses to extreme drought and some biotic events: Towards a selection according to hazard tolerance? , 2008 .

[14]  John Philip Cropper,et al.  TREE -RING SKELETON PLOTTING BY COMPUTER , 1979 .

[15]  Ernst van der Maaten,et al.  pointRes: An R package to analyze pointer years and components of resilience , 2015 .

[16]  F. Schweingruber,et al.  Extreme Tree Rings in Spruce (Picea abies [L.] Karst.) and Fir (Abies alba Mill.) Stands in Relation to Climate, Site, and Space in the Southern French and Italian Alps , 2000 .

[17]  F. Lebourgeois,et al.  Increased tree-growth synchronization of beech (Fagus sylvatica L.) in response to climate change in northwestern Europe , 2015 .

[18]  A. Bräuning Dendrochronology for the last 1400 years in eastern Tibet , 1994 .

[19]  G. Brūmelis,et al.  Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution limit , 2013 .

[20]  A. Cedro,et al.  Effects of climatic conditions on annual tree ring growth of the Platanus x hispanica "Acerifolia" under urban conditions of Szczecin , 2006 .

[21]  Martin Wilmking,et al.  Differential radial growth patterns between beech (Fagus sylvatica L.) and oak (Quercus robur L.) on periodically waterlogged soils. , 2013, Tree physiology.

[22]  European beech grows better and is less drought sensitive in mixed than in pure stands: tree neighbourhood effects on radial increment , 2014, Trees.

[23]  Andrew G. Bunn,et al.  A dendrochronology program library in R (dplR) , 2008 .

[24]  C. Goodess,et al.  Climate and signature years in west European oaks , 1989, Nature.

[25]  N. Breda,et al.  Climate-tree-growth relationships of European beech (Fagus sylvatica L.) in the French Permanent Plot Network (RENECOFOR) , 2005, Trees.

[26]  F. Schweingruber,et al.  Spatial patterns of central European pointer years from 1901 to 1971 , 2007 .

[27]  T. Kitzberger,et al.  Assessing dendroecological methods to reconstruct defoliator outbreaks on Nothofagus pumilio in northwestern Patagonia, Argentina , 2009 .

[28]  M. Santilli,et al.  Investigating surface movements of debris-covered Miage glacier, Western Italian Alps, using dendroglaciological analysis , 2007, Journal of Glaciology.

[29]  J. Eischeid,et al.  Aegean Tree-Ring Signature Years Explained , 2001 .

[30]  H. Grissino-Mayer,et al.  Climatic Regionalization and the Spatio-Temporal Occurrence of Extreme Single-Year Drought Events (1500–1998) in the Interior Pacific Northwest, USA , 2002, Quaternary Research.

[31]  A. Bräuning,et al.  Regional extreme climate events on the northeastern Tibetan Plateau since AD 1450 inferred from tree rings , 2011 .

[32]  M. Lena,et al.  Radial growth response of horse chestnut (Aesculus hippocastanum L.) trees to climate in Ljubljana, Slovenia , 2016 .

[33]  F. Schweingruber,et al.  Site ecological differences to the climatic forcing of spruce pointer years from the Lötschental, Switzerland , 2004 .

[34]  M. Andersson,et al.  Low pre-death growth rates of oak (Quercus robur L.)—Is oak death a long-term process induced by dry years? , 2011, Annals of Forest Science.

[35]  T. Rötzer,et al.  Dendroecological assessment of the complex causes of decline and recovery of the growth of silver fir (Abies alba Mill.) in Southern Germany , 2009 .