Visual display of the Aldo Leopold papers : 9/25/10-6 : Writings

				
LITHGOW OSBORNE                                        DIVISION OF FISH AND
GAME 
COMMISSIONER     STATE  OF                         WILLIAM C. ADAMS 
NEW YORK                        DIRECTOR 
JOHN T. GIBBS  CiMMSSINERJUSTIN T. MAHONEY 
DEPUT  COMMISSIONER                                       ASSISTANT DIRECTOR

JOHN L. HALPIN                                         J. V. SKIFF 
SECRETARY                 %                      SUPT. OF INLAND FISHERIES

SUMNER M. COWDEN 
SUPT. OF FISH CULTURE 
EMMELINE MOORE. PH. D. 
CHIEF AQUATIC BIOLOGIST 
GARDINER BUMP 
CONSERVATION DEPARTMENT                     SUPT. OF GAME 
HENRY A. TEAL 
SUPT. OF LAW ENFORCEMENT 
ALBANY                 JAMES H. HILDRETH 
SUPT. OF MARINE FISHERIES 
May 17,1943. 
Professor Aldo Leopold, 
University of Wisconsin, 
Iadison,Wisconsin. 
Dear Professor Leopold: 
This will acknowledge your letter of May 12th,concerning tree 
phenology. I have had a reply also from Professor Humphrey,who 
regrets that his schedule will not permit him to join in our 
proposed study. While three stations might be considerably more 
desireable than two,I see no good reason why you and I cannot go 
ahead. 
Since writing you in April,the weather here has been so 
unusual that I want to make some changes in my own schedule of 
operations. Our spring has been extremely backward and cold;we had 
a killing frost here in the valley (elevation 300 feet) on Friday 
last. It seems advisable,therefor,for me to continue this year with 
as much of my old tree list as I can,so that I can match the 1943 
data against my old series of 1933-1937,1940 and 1941. 
I would suggest,therefor,that we proceed as follows. Each of us 
will select three thrifty red pines 4-6 feet tall. pick off a few 
needles on the 1942 internode and make a mark on the stem with india 
ink which is 10 inches below the tip of the bud. If the buds have 
begun to expand,you can readily estimate where the tip of the dormant 
bud was. At weekly intervals (I do mine on Sunday),or at any convenient 
time so long as the gaps are not more than 7 days apart,measure the 
cumulative growth. Keep the data for the several trees separate. 
Averages are confusing,particularly if an accident happens to one of 
the trees. At the culmination of growth,the stem elongation will 
slow down sharply,then there will be an additional growth as the 
dormant bud is formed. Those on red pine are big enough to be readily 
measured. I do my measuring with a wooden yardstick,read to the 
nearest j inch. I believe that,if we can get a series,even tho it be 
small,from Wisconsin and from New York,we may get a clue as to whether 
there is a real difference between the two sites. Growth should 
culminate about mid-july,perhaps earlier. You will have to watch out 
for extra,seasonal growth-at least,it happens frecuently on sandy,dry 
sites here in New York. 
If you are in position to expand your study beyond a single set 
of trees,I am sure that you will find it interesting. One does not 
need more than a few trees of any one species on any one site. In fact, 
I customarily use only one,tho I often lone a species if my one tree 
has an accident of some sort. There is no limit to the possibilities, 
and we have not yet scratched the surface. 
I suggest,also,that you make a note of the blooming date of the 
common lilac,which is,I think,an indicator species of considerable