DOCSLIB.ORG

Building the Forest Inventory and Analysis Tree-Ring Data Set

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Building the Forest Inventory and Analysis Tree-Ring Data Set J. For. 115(4):283–291 PRACTICE OF FORESTRY https://doi.org/10.5849/jof.15-097 measurement Building the Forest Inventory and Analysis Tree-Ring Data Set Robert J. DeRose, John D. Shaw, and James N. Long The Interior West Forest Inventory and Analysis (IW-FIA) program measures forestland conditions at great extent (USDA Forest Service 1999), for which re- with relatively high spatial resolution, including the collection of tree-ring data. We describe the development cent radial growth increment data was ob- of an unprecedented spatial tree-ring data set for the IW-FIA that enhances the baseline plot data by tained, and formed the basis for gross growth incorporating ring-width increment measured from increment cores collected on IW-FIA plots. Whereas the IW-FIA calculations. Since the national adoption of program has used increment cores consistent with traditional forestry (stand age, site index, and vigor), there the current mapped-plot design and the an- are key differences in sampling approaches between foresters and dendrochronologists. We describe a nualized inventory (Gillespie 1999), the framework for preparation, interpretation, and archiving of the IW-FIA tree rings. Early results suggest that the measurement of any plots originally estab- data produced by this framework are useful for growth-and-yield studies, stand dynamics, and dendroclima- lished under periodic inventories and re- tology. We discuss the potential for tree-ring data to become a standard component of the FIA program. We tained in the annual inventory design were also compare and contrast the applications and procedures of dendrochronology with the FIA approach and show again considered “initial visits” during the how the two sources of data complement one another. first cycle of annual inventory (e.g., see USDA Forest Service 2001, section 7-4). Al- Keywords: dendroclimatology, dendroecology, dendrochronological principles, forest inventory, tree-ring though periodic and annual inventories science were “bridged” by remeasuring some trees common to both inventory types, popula- tion-level growth estimation was largely ther articles in the Forest Inven- will enhance the core FIA data and provide tory and Analysis (FIA) special important ancillary data to previously exist- based on increment cores and not remea- section illustrate the history of the ing tree-ring data sets (DeRose et al. 2012, sured diameters during the first cycle of an- O nual inventory (O’Connell et al. 2015). FIA program and the evolution of the pro- 2013). gram into the diverse forest resource inven- Tree-ring data have been used to vari- With most states in remeasurement un- tory that it is today (e.g., Shaw et al. 2016, ous extents within the FIA program (e.g., der annual inventory, the need to calculate Thompson 2016). As has been the case Chojnacky 1997, Witt 2010). Stand age is a gross growth, using increment core-derived throughout the program’s history, this evo- core variable, and it is usually determined by growth measurements, has decreased sub- lution is ongoing, and the program contin- growth ring count and weighting of size stantially. Growth estimation on remea- ually strives to both provide a consistent core classes within a stand (US Department of sured FIA plots is based on outside bark re- data set and add components that can be Agriculture [USDA] Forest Service 2015). measurement, with the exception of certain used to address future information needs Tree age, combined with height measure- slow-growing species, for which the ex- (Goeking 2015). The collection, analysis, ments, also provides entry to site index pected measurement error for outside bark and archiving of tree-ring data is a recent and yield models used in the core data diameter is likely to be a large fraction of the addition to the Interior West Forest Inven- (O’Connell et al. 2015). Many periodic in- actual growth (e.g., woodland species) tory and Analysis (IW-FIA) program that ventories were made up of “initial” plot visits (Goeking et al. 2014, p. 13). For the excep- Received July 3, 2015; accepted February 3, 2016; published online March 17, 2016. Affiliations: Robert J. DeRose ([email protected]), USDA Forest Service, Forest Inventory and Analysis, Ogden, UT. John D. Shaw ([email protected]), USDA Forest Service. James N. Long ([email protected]), Utah State University. Acknowledgments: This research was supported in part by the Utah Agricultural Experiment Station, Utah State University, Logan, UT. Approved as journal paper no. 8879. This article was prepared in part by employees of the USDA Forest Service as part of official duties and is therefore in the public domain. This article was greatly improved by the comments of Sara Goeking and two anonymous reviewers. We extend thanks to many dendrochronologists who provided unpublished tree-ring data helpful to building our FIA data archive: Connie Woodhouse, Jeff Lukas, Stephen Gray, Matt Bekker, Jim Speer, Margaret Evans, and Stan Kitchen. Journal of Forestry • July 2017 283 tions, we anticipate that increment core velopment of an FIA-based tree-ring data ar- ysis to remount all cores. FIA crews usually measurements will continue to be used in chive, present an overview of results we have mounted the cores in the field for secure some capacity. Cores will also be obtained, obtained from preliminary analyses, de- transportation, and the purpose of collecting for example, when partial stand replacement scribe future potential applications, and dis- the cores was only to obtain tree age and requires recomputation of stand age. cuss the potential for tree-ring data to be- recent growth increment data. As a result, However, the utility of tree-ring data is come a standard component of the FIA the orientation of most cores on the laths not limited to the applications traditionally program. In the process, we also compare was not optimal for what is now considered used by the FIA program. The myriad uses and contrast the applications of “tradi- standard tree-ring measurement and analy- of tree-ring data are well known and funda- tional” dendrochronological data and proce- sis. Cores were correctly oriented and re- mental not only in the field of forestry, but dures with the FIA approach and show how mounted to accentuate the transverse sec- also in related fields such as geography and the two sources of data may complement tion and then sanded using progressively ecology (Cook and Kairiukstis 1990, Speer each other. finer grades of sandpaper, followed by a final 2010). Variations in diameter growth incre- hand polishing (Stokes and Smiley 1968). ment potentially record events of stand dy- Development of an FIA-Based This provides a surface suitable for viewing namics (Fritts and Swetnam 1989) and can Tree-Ring Archive under a microscope. be excellent proxies for past climate condi- The IW-FIA core collection was “dis- A protocol consistent with conventional tions (Fritts 1976). Annual tree-ring forma- covered” during moving activities in the tree-ring preparation techniques (Speer 2010) tion in mid- to high-latitude trees represents Ogden Forestry Sciences Laboratory in was developed to ensure proper processing, the integration of physiological traits and en- 2007. The cores were in various states labeling, crossdating, measurement, and ar- vironmental conditions (e.g., climate, soil, and of preservation, typically with the cores chiving of the FIA tree-ring data. In addition stand density) over the course of a growing glued to a grooved wood lath and boxed by to establishing a linkage with the FIA data- season and is influenced by previous grow- state and inventory. Most were labeled with base, we maintained metadata consistent ing seasons (Fritts 1976). Because of these the information essential to linking a core to with the International Tree-Ring Data Bank controls on ring width, tree rings are impor- the corresponding tree records in the FIA (ITRDB) so as to make the archive easily tant archives of past growing conditions and database: state, county, plot, species, and di- accessible to dendrochronologists and other can serve as a proxy for them if the drivers ameter. The FIA database contained no in- researchers after it is ready for publication. can be identified. In the early 20th century, formation indicating that the core for a Increment cores had to be initially cross-ref- the field of dendrochronology was estab- given tree was held in the collection, but the erenced with the FIA database to determine lished based solely on the analysis of tree- potential list of trees with cores could be in- origin and measurement year. Decadal dots ring data (Douglass 1909). For FIA, the po- ferred by the presence of an age value in the were labeled, in consultation with a local tential for deeper (i.e., preinventory) TREE or SITETREE tables. An informal chronology, before cores were measured on a chronological analysis means that tree rings sampling of several boxes suggested that sliding stage that is paired with a digital Ϫ Ϫ provide a valuable temporal context in there were approximately 12,000 cores, readout at 3.94 ϫ 10 5 or 3.94 ϫ 10 4 in. which current tree and forest growth could 90% of which were assessed as likely to be resolution. be related to historical growth. useable. After the establishment of agree- Arguably, the most important principle In 2009, the IW-FIA began a partner- ments between FIA and the USU Dendro- in dendrochronology is crossdating, which is ship with the Dendrochronology Labora- chronology Laboratory, all cores were moved to based on matching patterns in ring-width tory at Utah State University (USU) with the USU campus for processing. variability among multiple tree-ring series to the goal of advancing the use of tree-ring Shortly after beginning the archiving determine the actual year of ring formation.
Load more

Recommended publications
  • Blue Intensity for Dendroclimatology: Should We Have the Blues?
    Dendrochronologia 32 (2014) 191–204 Contents lists available at ScienceDirect Dendrochronologia jou rnal homepage: www.elsevier.com/locate/dendro ORIGINAL ARTICLE Blue intensity for dendroclimatology: Should we have the blues? Experiments from Scotland a,∗ b c c Milosˇ Rydval , Lars-Åke Larsson , Laura McGlynn , Björn E. Gunnarson , d d a Neil J. Loader , Giles H.F. Young , Rob Wilson a School of Geography and Geosciences, University of St Andrews, UK b Cybis Elektronik & Data AB, Saltsjöbaden, Sweden c Department of Physical Geography and Quaternary Geology, Stockholm University, Stockholm, Sweden d Department of Geography, Swansea University, Swansea, UK a r t i c l e i n f o a b s t r a c t Article history: Blue intensity (BI) has the potential to provide information on past summer temperatures of a similar Received 1 April 2014 quality to maximum latewood density (MXD), but at a substantially reduced cost. This paper provides Accepted 27 April 2014 a methodological guide to the generation of BI data using a new and affordable BI measurement sys- tem; CooRecorder. Focussing on four sites in the Scottish Highlands from a wider network of 42 sites Keywords: developed for the Scottish Pine Project, BI and MXD data from Scots pine (Pinus sylvestris L.) were used Blue intensity to facilitate a direct comparison between these parameters. A series of experiments aimed at identify- Maximum latewood density ing and addressing the limitations of BI suggest that while some potential limitations exist, these can Scots pine Dendroclimatology be minimised by adhering to appropriate BI generation protocols. The comparison of BI data produced using different resin-extraction methods (acetone vs.
    [Show full text]
  • The Disclosure of Climate Data from the Climatic Research Unit at the University of East Anglia
    House of Commons Science and Technology Committee The disclosure of climate data from the Climatic Research Unit at the University of East Anglia Eighth Report of Session 2009–10 Volume II Oral and written evidence Ordered by The House of Commons to be printed 24 March 2010 HC 387-II Published on 31 March 2010 by authority of the House of Commons London: The Stationery Office Limited £0.00 The Science and Technology Committee The Science and Technology Committee is appointed by the House of Commons to examine the expenditure, administration and policy of the Government Office for Science. Under arrangements agreed by the House on 25 June 2009 the Science and Technology Committee was established on 1 October 2009 with the same membership and Chairman as the former Innovation, Universities, Science and Skills Committee and its proceedings were deemed to have been in respect of the Science and Technology Committee. Current membership Mr Phil Willis (Liberal Democrat, Harrogate and Knaresborough)(Chair) Dr Roberta Blackman-Woods (Labour, City of Durham) Mr Tim Boswell (Conservative, Daventry) Mr Ian Cawsey (Labour, Brigg & Goole) Mrs Nadine Dorries (Conservative, Mid Bedfordshire) Dr Evan Harris (Liberal Democrat, Oxford West & Abingdon) Dr Brian Iddon (Labour, Bolton South East) Mr Gordon Marsden (Labour, Blackpool South) Dr Doug Naysmith (Labour, Bristol North West) Dr Bob Spink (Independent, Castle Point) Ian Stewart (Labour, Eccles) Graham Stringer (Labour, Manchester, Blackley) Dr Desmond Turner (Labour, Brighton Kemptown) Mr Rob Wilson (Conservative, Reading East) Powers The Committee is one of the departmental Select Committees, the powers of which are set out in House of Commons Standing Orders, principally in SO No.152.
    [Show full text]
  • Volume 3: Process Issues Raised by Petitioners
    EPA’s Response to the Petitions to Reconsider the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act Volume 3: Process Issues Raised by Petitioners U.S. Environmental Protection Agency Office of Atmospheric Programs Climate Change Division Washington, D.C. 1 TABLE OF CONTENTS Page 3.0 Process Issues Raised by Petitioners............................................................................................5 3.1 Approaches and Processes Used to Develop the Scientific Support for the Findings............................................................................................................................5 3.1.1 Overview..............................................................................................................5 3.1.2 Issues Regarding Consideration of the CRU E-mails..........................................6 3.1.3 Assessment of Issues Raised in Public Comments and Re-Raised in Petitions for Reconsideration...............................................................................7 3.1.4 Summary............................................................................................................19 3.2 Response to Claims That the Assessments by the USGCRP and NRC Are Not Separate and Independent Assessments.........................................................................20 3.2.1 Overview............................................................................................................20 3.2.2 EPA’s Response to Petitioners’
    [Show full text]
  • Temporal Scales and Signal Modeling in Dendroclimatology Joel Guiot
    Temporal scales and signal modeling in dendroclimatology Joel Guiot To cite this version: Joel Guiot. Temporal scales and signal modeling in dendroclimatology. Past Global Changes Mag- azine, Past Global Changes (PAGES) project, 2017, 25 (3), pp.142-143. 10.22498/pages.25.3.142. insu-02269697 HAL Id: insu-02269697 https://hal-insu.archives-ouvertes.fr/insu-02269697 Submitted on 23 Aug 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 142 SCIENCE HIGHLIGHTS: CENTENNIAL TO MILLENNIAL CLIMATE VARIABILITY https://doi.org/10.22498/pages.25.3.142 Temporal scales and signal modeling in dendroclimatology Joël Guiot Tree rings are demonstrably good proxies for temperature or precipitation at timescales less than a century. Reconstruction based on multiple proxies and process-based modeling approaches are needed to estimate the climate signal at lower frequencies. Paleoclimatological proxies "represent component of the trend. Afterwards, the method is complex and needs a large records of climate that were generated tree leaf area stabilizes, and a fairly con- number of replicated series for the same through physical, chemical and/or biologi- stant quantity of xylem is distributed along species. No method is perfect and some cal processes.
    [Show full text]
  • Global Dendroclimatology in Sight from A
    780 Nature Vol. 287 30 October 1980 Global dendroclimatology in sight from A. Barrie Pittock Dendroclimatology, the systematic study pressure and that sampling should be con­ calibration and earlier instrumental and of past climates using tree growth centrated in regions which are historical data for verification, it should be characteristics as proxy climate data, is a climatologically important and/or where possible to produce a detailed and relatively young science. It is often there are gaps in coverage from instru­ continuous climate reconstruction from confused with the much older and related mental, historical or other proxy data. 1750. Because of the abundance of data for science of dendrochronology, the dating of There is growing confidence that with some calibration and verification, this could specimens by the use of tree-ring modification existing methods can extract prove the best continent-wide proxy sequences. Dendroclimatology has only useful climatic information from trees in climate data set in existence and Europe really developed as a science since the many different parts of the world. could become a test bed for refining 1940s, primarily as a result of the As dendroclimatology has expanded dendroclimatic methods. pioneering efforts of workers at the into new geographical areas over the last Five-hundred-year long chronologies Laboratory of Tree-Ring Research at the decade, techniques have been modified are available already from living conifers in University of Arizona. Elsewhere, the and refined. One example is the use of the Alps and at the northern tree-line and serious application of dendroclimatic density as well as ring-width measurements are expected from living oaks in Scotland, methods has only begun in the last five for climate reconstructions.
    [Show full text]
  • Application of Dendroclimatology in Evaluation of Climatic Changes
    JOURNAL OF FOREST SCIENCE, 64, 2018 (3): 139–147 https://doi.org/10.17221/79/2017-JFS Application of dendroclimatology in evaluation of climatic changes Mohammad Reza KHALEGHI* Department of Watershed Management Engineering, Faculty of Natural Resources, Torbat-e-Jam Branch, Islamic Azad University, Torbat-e-Jam, Iran *Corresponding author: [email protected] Abstract Khaleghi M.R. (2018): Application of dendroclimatology in evaluation of climatic changes. J. For. Sci., 64: 139–147. The present study tends to describe the survey of climatic changes in the case of the Bojnourd region of North Kho- rasan, Iran. Climate change due to a fragile ecosystem in semi-arid and arid regions such as Iran is one of the most challenging climatological and hydrological problems. Dendrochronology, which uses tree rings to their exact year of formation to analyse temporal and spatial patterns of processes in the physical and cultural sciences, can be used to evaluate the effects of climate change. In this study, the effects of climate change were simulated using dendrochro- nology (tree rings) and an artificial neural network (ANN) for the period from 1800 to 2015. The present study was executed using the Quercus castaneifolia C.A. Meyer. Tree-ring width, temperature, and precipitation were the input parameters for the study, and climate change parameters were the outputs. After the training process, the model was verified. The verified network and tree rings were used to simulate climatic parameter changes during the past times. The results showed that the integration of dendroclimatology and an ANN renders a high degree of accuracy and ef- ficiency in the simulation of climate change.
    [Show full text]
  • A Stable Isotope-Based Approach to Tropical Dendroclimatology
    Geochimica et Cosmochimica Acta, Vol. 68, No. 16, pp. 3295–3305, 2004 Copyright © 2004 Elsevier Ltd Pergamon Printed in the USA. All rights reserved 0016-7037/04 $30.00 ϩ .00 doi:10.1016/j.gca.2004.01.006 A stable isotope-based approach to tropical dendroclimatology 1, 2 MICHAEL N. EVANS * and DANIEL P. SCHRAG 1Laboratory of Tree-Ring Research, The University of Arizona, 105 W. Stadium, Tucson, AZ 85721, USA 2Department of Earth and Planetary Sciences, Harvard University, 20 Oxford St., Cambridge, MA 02138, USA (Received June 6, 2003; accepted in revised form January 6, 2004) Abstract—We describe a strategy for development of chronological control in tropical trees lacking demon- strably annual ring formation, using high resolution ␦18O measurements in tropical wood. The approach applies existing models of the oxygen isotopic composition of alpha-cellulose (Roden et al., 2000), a rapid method for cellulose extraction from raw wood (Brendel et al., 2000), and continuous flow isotope ratio mass spectrometry (Brenna et al., 1998) to develop proxy chronological, rainfall and growth rate estimates from tropical trees lacking visible annual ring structure. Consistent with model predictions, pilot datasets from the temperate US and Costa Rica having independent chronological control suggest that observed cyclic isotopic signatures of several permil (SMOW) represent the annual cycle of local rainfall and relative humidity. Additional data from a plantation tree of known age from ENSO-sensitive northwestern coastal Peru suggests that the 1997-8 ENSO warm phase event was recorded as an 8‰ anomaly in the ␦18Oof␣-cellulose. The results demonstrate reproducibility of the stable isotopic chronometer over decades, two different climatic zones, and three tropical tree genera, and point to future applications in paleoclimatology.
    [Show full text]
  • Progress in Australian Dendroclimatology: Identifying Growth Limiting Factors in Four Climate Zones
    Progress in Australian dendroclimatology: Identifying growth limiting factors in four climate zones Author Haines, Heather A, Olley, Jon M, Kemp, Justine, English, Nathan B Published 2016 Journal Title Science of the Total Environment Version Accepted Manuscript (AM) DOI https://doi.org/10.1016/j.scitotenv.2016.08.096 Copyright Statement © 2016 Elsevier. Licensed under the Creative Commons Attribution-NonCommercial- NoDerivatives 4.0 International Licence which permits unrestricted, non-commercial use, distribution and reproduction in any medium, providing that the work is properly cited. Downloaded from http://hdl.handle.net/10072/100111 Griffith Research Online https://research-repository.griffith.edu.au Progress in Australian dendroclimatology: Identifying growth limiting factors in four climate zones Heather A. Hainesa1, Jon M. Olleya, Justine Kempa, Nathan B. Englishb a Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, QLD, 4101, Australia b School of Medical and Applied Sciences, Central Queensland University, 538 Flinders Street West, Townsville, QLD, 4810, Australia 1 Corresponding author. email address: [email protected] Abstract: Dendroclimatology can be used to better understand past climate in regions such as Australia where instrumental and historical climate records are sparse and rarely extend beyond 100 years. Here we review 36 Australian dendroclimatic studies which cover the four major climate zones of Australia; temperate, arid, subtropical and tropical. We show that all of these zones contain tree and shrub species which have the potential to provide high quality records of past climate. Despite this potential only four dendroclimatic reconstructions have been published for Australia, one from each of the climate zones: A 3592 year temperature record for the SE-temperate zone, a 350 year rainfall record for the Western arid zone, a 140 year rainfall record for the northern tropics and a 146 year rainfall record for SE-subtropics.
    [Show full text]
  • ABSTRACT Branching Into the Past: Using Dendrochronology and Pinus
    ABSTRACT Branching into the Past: Using Dendrochronology and Pinus echinata to Examine Drought in East Texas Victoria Rose Director: Jacquelyn Duke Ph.D. With a rapidly changing climate, it is more important than ever to understand climate conditions of the past in order to anticipate the climate conditions of the future. This study focuses on the information tree cores can uncover about past climate through the field of dendrochronology. Dendrochronology takes advantage of the fact that most trees produce annual rings with yearly variation in the width due to limiting factors such as rainfall and temperature. This work investigates the ability of Pinus echinata (shortleaf pine) from East Texas to act as proxy data for drought in the region. Thirty- three tree core samples were taken at the Sam Houston State University Center for Biological Field Studies and processed using standard dendrochronology methods. The master chronology created was then compared to the average Palmer Drought Severity Index for each growing season. No statistical correlation was found between the two, but a six-year moving average revealed that the growth of the trees was influenced by land management practices through time. APPROVED BY DIRECTOR OF HONORS THESIS Dr. Jacquelyn Duke, Department of Biology APPROVED BY THE HONORS PROGRAM Dr. Elizabeth Corey, Director DATE: BRANCHING INTO THE PAST: USING DENDROCHRONOLOGY AND PINUS ECHINATA TO EXAMINE DROUGHT IN EAST TEXAS A Thesis Submitted to the Faculty of Baylor University In Partial Fulfillment of the Requirements for the Honors Program By Victoria Rose Waco, Texas May 2017 TABLE OF CONTENTS Acknowledgements……………………………………………….iii CHAPTER ONE.
    [Show full text]
  • PALEOCLIMATOLOGY Reconstructing Climates of the Quaternary
    PALEOCLIMATOLOGY Reconstructing Climates of the Quaternary THIRD EDITION RAYMOND S. BRADLEY University of Massachusetts, Amherst, Massachusetts AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Contents Acknowledgments xi 4. Dating Methods II Front Cover Photograph xiii Paleomagnetism 103 Foreword xv The Earth’s Magnetic Field 104 Preface to the Third Edition xix Magnetization of Rocks and Sediments 105 The Paleomagnetic Timescale 107 Geomagnetic Excursions 108 1. Paleoclimatic Reconstruction Relative Paleointensity Variations 110 Secular Variations of the Earth’s Magnetic Field 111 Introduction 1 Dating Methods Involving Chemical Changes 111 Sources of Paleoclimatic Information 4 Amino Acid Dating 113 Levels of Paleoclimatic Analysis 9 Obsidian Hydration Dating 124 Modeling in Paleoclimatic Research 10 Tephrochronology 125 Biological Dating Methods 129 2. Climate and Climatic Variation Lichenometry 129 Dendrochronology 135 The Nature of Climate and Climatic Variation 13 5. Ice Cores The Climate System 16 Feedback Mechanisms 24 Introduction 137 Energy Balance of the Earth and Its Stable Isotope Analysis 141 Atmosphere 27 Stable Isotopes in Water: Measurement and Timescales of Climatic Variation 33 Standardization 143 Variations of the Earth’s Orbital Parameters 36 Oxygen-18 Concentration in Atmospheric Solar Forcing 46 Precipitation 144 Volcanic Forcing 50 Factors Affecting the Stable Isotope Record in Ice Cores 145 3. Dating
    [Show full text]
  • The Manuscript Reviews Recent Development of Isotopic Dendroclimatology, Addressing Possible Divergence Problem in Tree-Ring D13c and D18o
    The manuscript reviews recent development of isotopic dendroclimatology, addressing possible divergence problem in tree-ring d13C and d18O. In my opinion, this kind work is very important when isotopic dendroclimatology has been paid more attention and plays more important role in high- resolution paleoclimate reconstruction. However, the current manuscript should be reorganized and concentrated in d13C. Physiological mechanisms between tree-ring d13C and d18O are quite different, therefore, comparing with tree-ring d13C, tree-ring d18O did not show recognizable effects from rising pCO2 (Lines 240-241) and pollution (Lines 424-425). Just as the authors said in Lines 514-515, tree-ring d18O is a more appropriate proxy for climate reconstruction. And, the phenomenon of divergence between the d18O and climate is really few worldwide. I also suggest the authors adding one section discussing uncertainty. Isotopic dendroclimatology is a subject based on chemical experiment. Unlike tree-ring width or density, the result of tree-ring d13C or d18O measurements are different to verified again from their core or disk samples, due to time consuming and great expense. It is possible to introduce mistakes during many steps of experiments, for example, impure cellulose and unreliable measurements caused by bad condition of the isotope ratio mass spectrometer. Some other uncertainties also exist. First is sampling strategy. We should understand what kind of tree could be used for climate reconstruction. As recommended by classical “The principle of limiting factors” (Fritts 1976), site selection is very important when one would employ trees to infer climate change. It is also important to isotopic dendroclimatology.
    [Show full text]
  • Tree Rings Reveal Climate Change Past, Present, and Future1
    Tree Rings Reveal Climate Change Past, Present, and Future1 KEVIN J. ANCHUKAITIS Associate Professor School of Geography and Development Laboratory of Tree-Ring Research University of Arizona Introduction Earth’s climate system exhibits variability in both temperature and hydroclimate across a range of spatial and temporal scales covering several orders of magnitude. However, existing observations of the climate system from weather stations and satellites are too short or too sparse to completely characterize this variability, particularly at decadal, multidecadal, and centennial time scales. And yet these modes of variability are critical for short- and medium-term natural resources management, climate policy, and economic planning. This natural vari- ability in the climate system is also superimposed on the trends and changes caused by the anthropogenic emission of greenhouse gases, complicating straightforward detection and attribution of human modification of Earth’s climate system (Solomon et al. 2011) and leaving a lacuna in our knowledge of the complete range of variability in temperature and hydroclimate. A more complete understanding of internal variability in the climate system is necessary for decadal predic- tion, vulnerability reduction, and long-term adaptation to climate vari- ability and change (Meehl et al. 2009; Vera et al. 2010). Paleoclimatology addresses the limitations of the instrumental era by extending climate information back into the past using “proxies,” and tree rings are one of the most important sources of information about the climate of the last several thousand years. The various phys- ical and chemical characteristics of the annual rings reflect past climate and environmental conditions, prior to our modern period of moni- toring and measuring the Earth system, and as such effectively allow us to recover observations of the past.
    [Show full text]