158 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



21. Continental Notes— France. 



By A. G. IIobart-Hampdex. 



I. — At the meeting of the Society of Franche Comte and 

 Belfort, M. Martin described a curious area in Upper Alsace, 

 between Mulhouse, Colmar and Neu Brisach, which is so 

 unusually dry that the rainfall is less than 16 inches, 50% less 

 than in the driest plains of France. The effect of this low 

 rainfall is reinforced by the fact that the marshes have been 

 drained. Almost touching this region is the mountain known 

 as the " Ballon d' Alsace," in the Vosges, where the mean rain- 

 fall is nearly 80 inches. This reminds one of the curious case 

 of Ratnagiri, on the coast below Bombay, where (if I am right) 

 the rainfall is between 300 and 400 inches, whereas only a 

 few miles farther east, but on the farther side of the Ghauts, 

 there is a place with only some 18 inches. 



Into this dry region in Alsace, however, the Forest of Hardt 

 (or Harth) intrudes, and just here — a significant fact— the 

 rainfall is nearly 24 inches. The vegetation responds. The 

 pubescent oak, a southern variety of the sessile oak, is met with. 

 A number of herbaceous plants belonging to a lower latitude 

 also are found, as, for example, Artemisium camphorata^ which 

 in the Rhone valley does not grow farther north than the line 

 of Grenoble. The beech will not thrive in this region. 



The lack of water, further, reduces the rate of growth. The 

 outturn of the Forest of Hardt is always low, and M. Martin 

 convinced himself, from borings, that in the drought of 1921 

 the growth would be only two-fifths of that of a normal year, 

 which, he calculated, would mean a loss of 500,000 frs. to 

 the State, To which we might add that since a phenomenal 

 drought is followed by a phenomenal seed year, and since a 

 heavy seeding means a great reduction in the growth of wood, 

 there will be further loss — a loss in material certainly much 

 greater than the three-fifths due to the drought. I may illustrate 

 this by a concrete example. It has been my practice to measure 

 a certain plot of beech every four or five years, to ascertain 

 the growth of the stems in girth. Ordinarily this has shown me 

 that, after eliminating the suppressed stems, it takes about 

 twenty-seven years, on an average, for the stems to make a 

 foot of girth. On one occasion, however, I measured the plot 



