Welcome to our interactive 
Hubbard Brook Growth rate program!

This program calculates tree radial growth rates at Hubbard Brook, online and on the fly!!  The calculations are for the Valley plots, also known as the "Schwarz" plots, since they were primarily Paul Schwarz's effort.  The 431 plots are each 500 square meters, arranged in a symmetric grid system over the entire Hubbard Brook valley. Tree core data used in this program were taken on only 358 of these plots. Tabular output includes average radial growth rate by species.

Please do not use any of these numbers in any official way without first checking with the Hubbard Brook research team.

If you are losing the page when reloading images in the calculators, please go back to the W6 front page and reenter by clicking "click here if your browser does not support frames".

This program is optimized for Internet Explorer 6.

Valley plots

Please choose a year:
Please choose a species for which you would like to see graphical summaries:
Please choose the number of years to include. This will take the last X annual ring widths and average them for each tree. (Only about one quarter of the cores have ring data exceeding 20 years):

You may select a diameter range over which you would like to make the summaries. The smallest diameter included in the data is 10 cm and there are no trees over 120 cm dbh. If no diameter range is specified, the program will run for all trees >10 cm dbh.
Enter lower diameter (in cm):
Enter upper diameter (in cm) :

Please indicate by number which of the following plot summary options you are going to use (Option 0 includes all plots):  

1 . Choose individual plots (hold down the shift key to select large blocks of plots or hold down the Ctrl key to select several individual plots):
                click here for a plot map

2. OR, enter a lower and upper elevation limit (in meters). The elevation range for the Valley plots is 245 to 910 m. (Please left justify and leave one space between the numbers, e.g. 600 700):

3. OR, enter a range in slope aspect (azimuth compass bearing). For example, for slopes facing due north to southeast, use 0 and 135. (Please left justify and leave one space between the numbers, e.g. 0 135):

4. OR, enter a single plot. Plots in the Valley which include tree cores are numbered 1 to 400 with some skipped numbers. There are 358 total plots in the tree core dataset :

Would you like to identify those plots which have higher growth rates for the species chosen above? 

Please enter the minimum average growth rate this species must exhibit. For example, if you are interested in plots with average radial growth rates that are at least 1.0 mm/yr, then use 1.0:

Would you like to generate a list of the average growth rate for each tree used in the calculation?  (This may be quite a long list and could take some extra time.):

 

 


Click here for Tom's very specific miscellaneous notes regarding this calculator.

The data used in the calculations have not yet been made public.

        Please note that this page may undergo changes in the future as we develop new ideas for calculating phytosociology. In the meantime, we welcome any suggestions that you may have for this page at thomas.siccama@yale.edu.

 

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Web page created December 2003
by Thomas Siccama and Ellen Denny