date: Thu May  4 01:03:24 2000
from: Keith Briffa <k.briffa@uea.ac.uk>
subject: Re: Question about Nature Paper 
to: Werner Kurz <wkurz@essa.com>


Dear Werner 
    reply to your message in attached WORD file. Data you request are

Data from final panel (ALL) of Briffa et al. (1998)
All data have been smoothed with a decadal filter

      Year Apr-Sep T   Density
  1881.000    -0.648    -0.338
  1882.000    -0.739    -0.599
  1883.000    -0.779    -0.864
  1884.000    -0.728    -1.024
  1885.000    -0.567    -0.942
  1886.000    -0.355    -0.655
  1887.000    -0.182    -0.356
  1888.000    -0.085    -0.203
  1889.000    -0.081    -0.227
  1890.000    -0.179    -0.355
  1891.000    -0.314    -0.442
  1892.000    -0.366    -0.392
  1893.000    -0.273    -0.252
  1894.000    -0.075    -0.126
  1895.000     0.142    -0.040
  1896.000     0.308     0.036
  1897.000     0.359     0.066
  1898.000     0.259    -0.016
  1899.000     0.049    -0.153
  1900.000    -0.208    -0.221
  1901.000    -0.486    -0.207
  1902.000    -0.701    -0.165
  1903.000    -0.717    -0.098
  1904.000    -0.546    -0.005
  1905.000    -0.405     0.073
  1906.000    -0.467     0.086
  1907.000    -0.665     0.022
  1908.000    -0.804    -0.080
  1909.000    -0.795    -0.184
  1910.000    -0.731    -0.313
  1911.000    -0.712    -0.480
  1912.000    -0.696    -0.592
  1913.000    -0.589    -0.546
  1914.000    -0.434    -0.418
  1915.000    -0.358    -0.366
  1916.000    -0.382    -0.404
  1917.000    -0.375    -0.381
  1918.000    -0.225    -0.174
  1919.000     0.027     0.151
  1920.000     0.232     0.390
  1921.000     0.278     0.410
  1922.000     0.180     0.244
  1923.000     0.055     0.039
  1924.000     0.000    -0.071
  1925.000     0.001    -0.041
  1926.000    -0.007     0.084
  1927.000    -0.021     0.234
  1928.000     0.044     0.381
  1929.000     0.262     0.541
  1930.000     0.587     0.712
  1931.000     0.868     0.838
  1932.000     1.010     0.863
  1933.000     1.063     0.798
  1934.000     1.135     0.726
  1935.000     1.295     0.738
  1936.000     1.511     0.837
  1937.000     1.653     0.915
  1938.000     1.603     0.859
  1939.000     1.393     0.691
  1940.000     1.167     0.557
  1941.000     1.053     0.595
  1942.000     1.061     0.794
  1943.000     1.102     1.010
  1944.000     1.102     1.131
  1945.000     1.087     1.148
  1946.000     1.116     1.086
  1947.000     1.178     0.966
  1948.000     1.219     0.825
  1949.000     1.215     0.698
  1950.000     1.212     0.621
  1951.000     1.253     0.619
  1952.000     1.278     0.649
  1953.000     1.168     0.598
  1954.000     0.893     0.421
  1955.000     0.578     0.208
  1956.000     0.400     0.094
  1957.000     0.450     0.139
  1958.000     0.668     0.310
  1959.000     0.908     0.502
  1960.000     1.029     0.576
  1961.000     0.967     0.437
  1962.000     0.746     0.119
  1963.000     0.448    -0.237
  1964.000     0.196    -0.482
  1965.000     0.107    -0.560
  1966.000     0.174    -0.564
  1967.000     0.254    -0.632
  1968.000     0.242    -0.745
  1969.000     0.177    -0.788
  1970.000     0.146    -0.762
  1971.000     0.190    -0.758
  1972.000     0.319    -0.793
  1973.000     0.503    -0.841
  1974.000     0.664    -0.910
  1975.000     0.723    -1.006
  1976.000     0.641    -1.093
  1977.000     0.465    -1.124
  1978.000     0.340    -1.064
  1979.000     0.386    -0.918
  1980.000     0.564    -0.740
  1981.000     0.730    -0.575
  1982.000     0.798    -0.434
  1983.000     0.776    -0.339
  1984.000     0.716    -0.336
  1985.000     0.709    -0.415
  1986.000     0.869    -0.502
  1987.000     1.219    -0.558
  1988.000     1.635    -0.605
  1989.000     1.920    -0.659
  1990.000     1.960    -0.734
  1991.000     1.814    -0.856
  1992.000     1.653    -0.984

      Year Jun-Aug T RingWidth
  1881.000    -0.473     0.036
  1882.000    -0.522    -0.143
  1883.000    -0.572    -0.256
  1884.000    -0.597    -0.349
  1885.000    -0.548    -0.529
  1886.000    -0.443    -0.828
  1887.000    -0.353    -1.108
  1888.000    -0.324    -1.154
  1889.000    -0.364    -0.882
  1890.000    -0.448    -0.422
  1891.000    -0.483    -0.019
  1892.000    -0.386     0.145
  1893.000    -0.190     0.059
  1894.000     0.017    -0.124
  1895.000     0.190    -0.212
  1896.000     0.303    -0.142
  1897.000     0.311    -0.055
  1898.000     0.207    -0.124
  1899.000     0.053    -0.296
  1900.000    -0.122    -0.376
  1901.000    -0.356    -0.336
  1902.000    -0.589    -0.303
  1903.000    -0.655    -0.344
  1904.000    -0.526    -0.445
  1905.000    -0.406    -0.563
  1906.000    -0.474    -0.609
  1907.000    -0.663    -0.520
  1908.000    -0.787    -0.362
  1909.000    -0.787    -0.253
  1910.000    -0.761    -0.233
  1911.000    -0.798    -0.254
  1912.000    -0.865    -0.212
  1913.000    -0.857    -0.032
  1914.000    -0.749     0.225
  1915.000    -0.617     0.409
  1916.000    -0.514     0.435
  1917.000    -0.422     0.311
  1918.000    -0.291     0.083
  1919.000    -0.106    -0.154
  1920.000     0.071    -0.256
  1921.000     0.146    -0.144
  1922.000     0.086     0.090
  1923.000    -0.034     0.270
  1924.000    -0.095     0.310
  1925.000    -0.047     0.265
  1926.000     0.076     0.217
  1927.000     0.228     0.182
  1928.000     0.417     0.148
  1929.000     0.675     0.142
  1930.000     0.959     0.176
  1931.000     1.141     0.194
  1932.000     1.171     0.170
  1933.000     1.145     0.185
  1934.000     1.202     0.353
  1935.000     1.393     0.683
  1936.000     1.619     1.072
  1937.000     1.714     1.386
  1938.000     1.604     1.540
  1939.000     1.367     1.529
  1940.000     1.131     1.428
  1941.000     0.951     1.332
  1942.000     0.818     1.292
  1943.000     0.732     1.296
  1944.000     0.716     1.277
  1945.000     0.759     1.157
  1946.000     0.792     0.921
  1947.000     0.747     0.652
  1948.000     0.619     0.468
  1949.000     0.496     0.438
  1950.000     0.491     0.567
  1951.000     0.644     0.815
  1952.000     0.866     1.081
  1953.000     1.002     1.244
  1954.000     0.968     1.222
  1955.000     0.816     1.024
  1956.000     0.696     0.755
  1957.000     0.729     0.562
  1958.000     0.918     0.488
  1959.000     1.129     0.394
  1960.000     1.185     0.116
  1961.000     1.002    -0.290
  1962.000     0.664    -0.520
  1963.000     0.329    -0.326
  1964.000     0.117     0.187
  1965.000     0.076     0.673
  1966.000     0.157     0.890
  1967.000     0.242     0.840
  1968.000     0.290     0.641
  1969.000     0.371     0.328
  1970.000     0.511    -0.154
  1971.000     0.662    -0.770
  1972.000     0.790    -1.367
  1973.000     0.858    -1.817
  1974.000     0.806    -2.035
  1975.000     0.617    -1.959
  1976.000     0.357    -1.609
  1977.000     0.135    -1.114
  1978.000     0.061    -0.664
  1979.000     0.173    -0.426
  1980.000     0.396    -0.399
  1981.000     0.611    -0.383
  1982.000     0.749    -0.215
  1983.000     0.784     0.035
  1984.000     0.722     0.156
  1985.000     0.639     0.054
  1986.000     0.685    -0.195
  1987.000     0.957    -0.508
  1988.000     1.365    -0.819
  1989.000     1.681    -0.952
  1990.000     1.742    -0.780
  1991.000     1.587    -0.463
  1992.000     1.396    -0.290



At 11:56 AM 4/28/00 -0700, you wrote:
>Dear Dr. Briffa,
>
>I am in the process of preparing the opening keynote address for an
>international boreal forest carbon cycling conference in Edmonton, Canada,
>May 8 - 12. I would like to make reference to your paper in Nature on
>reduced sensitivity of recent tree-growth to temperature at high northern
>latitudes.
>
>I have read your paper with great interest when it appeared and have
>recently read it again. As you are aware, a community of scientists is
>attributing the missing sink to terrestrial ecosystems in the northern
>hemisphere, others are arguing that CO2 fertilization, N deposition and
>other mechanisms are the cause for increased tree growth in the north. Yet,
>neither the forest inventory data and modelling results (see our own work
>e.g. Kurz and Apps, 1999, Ecol. Appl. 9: 526-547) nor the data from tree
>ring analyses (see your Nature paper) are supporting these hypotheses.
>
>None of these studies are definitive, and there is clearly room for
>alternative interpretations. For example, I appreciate that growth of
>individual trees (as studied by dendrochronology) is not a direct indicator
>of stand dynamics and therefore net ecosystem production. BUT - 314 studies
>across the northern hemisphere should pick up a signal from CO2
>fertilization, N deposition or climate change related changes in the
>relationship between temperature and growth rates. If anything, your data
>indicate the opposite trend, i.e. that growth was reduced even where
>temperature has been increasing. This would argue AGAINST enhanced growth in
>the north, not for it. Or am I misinterpreting something?
>
>The point I would like to make in my presentation is that if these
>growth-enhancing processes were at work, then one should see a signal in the
>growth rings, yet this does not appear to be the case. I will phrase this as
>an observation, not as an argument that there these processes are NOT at
>work.
>
>Three questions for you:
>
>1. Am I correct in interpreting your results to indicate that growth (at
>least at the tree level) has decreased for similar temperatures and that
>this is inconsistent with the claims of enhanced tree growth in the north?
>
>2. Would it be possible to obtain from you the data used to plot the curves
>for ALL regions (bottom panel) of Figure 2 in your Nature paper. If yes, I
>would very much like to turn it into a figure for my presentation - this is
>very difficult to do with the small print in the Nature paper. I would
>greatly appreciated it if you could make these data available. I will of
>course acknowledge the source in the presentation.
>
>3. Have you published another paper on the subject that would further
>strenghten the arguments? If so, could you please provide the reference so
>that I can retrieve the paper.
>
>Many thanks for your time.  
>
>
>Best regards,  Werner
>
>
>=========================================================
>Werner A. Kurz, Ph.D.
>Forestry Team Leader
>ESSA Technologies Ltd.
>1765 W. 8th Avenue
>Vancouver, BC V6J 5C6
>Tel: 604-733-2996
>Fax: 604-733-4657
>e-mail: wkurz@essa.com
>www.essa.com 
>
>
>
>
>
>
