338 



BOTKIN, JANAK, AND WALLIS 



1000 



+ 100% 

  , Normal 



Sugar maple 

 762-m elevation 

 1.6-m soil depth 



(a) 



> A < 9 



Y Y?T 



Y9 



S .*** 



*« 



itfiPfol 



99 



"liliiiif 



IH-J 



99? 99 A 



4 * 





40 80 120 160 200 240 280 320 360 400 440 480 520 



YEARS SINCE CLEAR-CUT 



2800 



2400 



Q- 



- V 

 - I 



§ 2000 



Spruce 



— 762-m elevation 



— 1.6-m soil depth 



az 1600 



< 



_i 



<2 1200 

 < 



CO 



< 800 



O 



400 







Normal 



+ 100% 



i 



' ' Ml ml 



"Till 1 



i 1 ' ..i.' 1 ' 



9 ?9 



99 



I «'""„" 







99? 



?$ 







(b) 



AqS«**T i I i I i 1 i I i 1 i I i I i I i I i I i 



40 80 120 160 200 240 280 320 360 400 440 480 520 



YEARS SINCE CLEAR-CUT 



Fig. 5 Long-term trends in basal area contributed by sugar maple (a), spruce (b), balsam fir (c),and 

 white birch (d). Conditions as in Fig. 4. 



