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

				
LITHGOW OSBORNE                                       DIVISION OF FISH AND
GAME 
COMMISSIO R      STATE OF NEW YORK                WILLIAM C. ADAMS 
STAT OFNEW  ORKDIRECTOR 
JOHN T. GIBBS                                         JUSTIN T. MAHONEY 
DEPUTY COMMISSIONER       F  ,                           ASSISTANT DIRECOR

J. V. SKIFF 
JOHNSECRETARY L NSUPT. OF INLAND FISHERIES 
SSUMNER M. COWDEN 
SUPT. OF FISH CULTURE 
EMMELINE MOORE, PH.D. 
CHIEF AQUATIC BIOLOGIST 
GARDINER SUMP 
CONSERVATION DEPARTMENT                     SUPT. OF GAME 
HENRY A. TEAL 
SUPT. OF LAW ENFORCEMENT 
ALBANY (7)            JAMES H. HILDRETH 
SUPT. OF MARINE FISHERIES 
August 16,1943. 
Professor Aldo Leopold, 
424 University Farm Place, 
Madison,Wisconsin. 
Dear Professor: 
I am decidedly tardy in replying to your letter of Tuly 18th. 
Will have to blame it on field work and time spent trying to pry 
nominating petitions out of the members of the S.A.F. 
The data on red paine are most interesting. The fidelity with 
which the curves for Madison and Stephentown follow each other tends 
to confirm the idea that the pattern of growth curves (at least for 
softwoods) is a specific constant. Too bad we couldn't have had data 
from Pennsylvania,too. 
I would attach relatively little significance to differences in 
amount of growth. My specimens were small trees alnog the windward 
edge of a plantation where the dominant trees average 20 feet. They were

the only ones small enough for convenient measurement. However,the 
site is too well-watered for typical red pine site,was originally 
Hemlock-Hard Maple. Red pine has a c.a.i. of 20 inchesusually. 
Without more data,I would not hazard a guess as to why your 
trees were 10 days earlier than mine. The season here has been very 
backward,as has yours. The climates are about the same,modified 
continental here being only slightly different from your unmodified 
continental. Latitude of Stephentown is 420 30' pluswhile yours 
approximates 430 -- not much difference there. Current rainfall seems 
to make little differencefor the pines grow with food stored from the 
provious year. That reduces the possible factors pretty sharply,leaves 
only current temperatures. Weather station records have their 
limitations. I have tried summing excess temperatures over 420 and 
many another dizzy trick,but never could get a correlation; 
differences sometimes as wide as 1000%. I have a thordly unscientific 
hunch thet the governing factor determining the onset of terminal 
growth is light,as controlled by the length of day. The minor 
fluctuations may be due to local combinations of teiperkture,both 
soil and air. There is a wide-open field here for some bright young 
forester.