cc: stepan@ipae.uran.ru, eavaganov@forest.akadem.ru
date: Mon Feb  4 09:56:12 2002
from: Keith Briffa <k.briffa@uea.ac.uk>
subject: Re: Tree growth/ uV link? 
to: "Svetlana Bondarenko" <bondarenko@iao.ru>

   Dear Professor Zuev
   I am very interested to see that you are also looking at the possibility that uV radiation
   increases at high latitudes might be impacting on tree-growth.
   Along with several colleagues here and in Switzerland (Fritz Schweingruber) , along with
   Academician Vaganov and Professor Shiyatov from your country,  I have been very interested
   in the apparent changing relationship between measured tree growth (ring width but
   particularly ring maximum density) and summer temperature - not just in Russia but also in
   other relatively high-latitude or high-elevation sites in the U.S. , Canada and Europe. We
   have established that there is a slow change , with the link between these data weakening
   over the last 50 years , but year to year changes on a large scale staying  parallel. I
   have suggested in several conferences and in press that higher uV (as a consequence of
   reduced total ozone ) may be factor , but this is speculation based on some reading of the
   physiological literature that suggests that photosynthetic processes may be impaired in
   high uV experiments. There is also the coincidental observation of reducing ozone at some
   long record sites (such as Arosa) since the 1950s. However, other environmental variables ,
   e.g. the atmospheric clarity, also show negative trends over this period, so there can be
   little statistical evidence offered . We have though tried looking in some detail at the
   association between temperature residuals (that is the difference series between our
   empirical estimates of temperature change as calculated from tree-growth , and observations
   of summer mean temperatures) across the different parts of our network , and variations in
   total ozone as extracted from the TOMS satellite data . This is intriguing but not
   convincing ( we would hope to see a positive correlation ) - but in many areas our
   tree-ring data (especially the density data) do not come up to the present and the
   satellite records are short (only from the late 1970s) so again our degrees of freedom are
   low for this comparison. This later work is not published but I will send a few references
   to our earlier papers , and in the meantime I will read the text that you have sent me.
   Please be a little patient as I am very bogged down with several passed deadlines and
   teaching at present.
   Very best wishes
   Keith
   At 03:21 PM 2/1/02 +0800, you wrote:


     Dear Doctor Briffa,<?xml:namespace prefix = o ns =
     "urn:schemas-microsoft-com:office:office" />

     Quite recently, our results concerning the reconstruction of paleobehavior of
     ozonosphere from dendrochronologic wood density data were presented at the international
     conference «Ecology of Siberia, the Far East and the Arctic» in Tomsk, and a little
     later at the Sukachev Institute of Forest in Krasnoyarsk. These results have stirred
     real interest. Academician Vaganov, Director of Institute of Forest, referred to your
     papers, and prompted that it is you who pointed out to some mismatches appearing between
     dendrochronologic time series and temperature/precipitation variations, and who related
     dendrochronologic data to some other parameters such as ozone concentration. May be our
     results will be of interest for you. So, we send you a translation of our paper
     published in:
     Environment of Siberia, the Far East and the Arctic: Selected papers presented at the
     International Conference ESFEA 2001, Tomsk, Russia. September 5-8, 2001. P 3-12, V. V.
     Zuev and Yu. P. Turov, Editors.
     We would be indebted if you respond to our results in order to bridge scientific
     contacts in development of this branch of dendrochronology. Academician Vaganov, who
     discussed this problem with us, also considers it useful to contact you.
     Our research area is the study of stratospheric changes using the laser sensing methods,
     primarily by studying the changes in ozonosphere (Laboratory of Remote Spectroscopy of
     the Atmosphere, http://eng.iao.ru). We are strongly interested in problems of natural
     variability of ozonosphere. Unfortunately, in the field of dendrochronology, we are only
     making first steps, having few sources of the corresponding dendrochronologic data. In
     particular, from the paper it is clear that ozone is found to be most strongly
     correlated with density of Stone Pine in Arosa, Switzerland; whereas other data for this
     tree species for other geographic regions are very difficult to find. Possibly, there
     may be some other types of sensitivity to the effect of UV-B radiation. We would be very
     indebted if you give us the corresponding bearings in this direction.


                                                                      Prof.  Vladimir V. Zuev,

                                                               Corresponding Member of the RAS

                                                                       Svetlana L. Bondarenko,

                                                                         postgraduate students

                                                                         Fax: 7-3822-25-83-85.

                                                                  E-mail: [1]bondarenko@iao.ru

   --
   Professor Keith Briffa,
   Climatic Research Unit
   University of East Anglia
   Norwich, NR4 7TJ, U.K.

   Phone: +44-1603-593909
   Fax: +44-1603-507784
   [2]http://www.cru.uea.ac.uk/cru/people/briffa[3]/