瘠悪地におけるアカシア・モリシマの成長の一例

In this paper, we report the growth of Acacia mollissima planted in the Experimental forest of Shimane Agricultural College near Matsue city. In May 1956, germinated seeds treated, with sulphuric acid were set in pots made of vinyl chloride sheet, and in pots made of dried compost. These pots were planted alternatively on the bench cut on the slope on which some fruit trees planted formerly.
Between these pots, germinated seeds were planted directly for contrast. The slope is covered by pinus densiflora poorly grown, some shrubs such as Ilex, Quercus and Vaccinium, and some weeds. The soil is reddish and of dry type, A_0 layer and A - layer is thin, B - layer is moderately deep. In general, soil is rather poor and cilmate is too cold in winter to make Acacia grow well. Heights of Acacia were measured in Nov. 1956, and trees in compost pots were taller than others. After that, these trees had not been cared for 3 years from 1957 to 1959, then these trees were measured, Results obtained were as follows :
mean height of trees ・・・ 5.32±1.08m.
maximum ht. of trees ・・・ 7.80m.
mean b.h. diameter ・・・6.18±2.73cm.
maximum b.h.d. ・・・・・11.00cm.
mean crown width・・・・・2.58±1.13m.
numbers of germinative seeds planted at first・・ 39.
numbers of trees in Nov. 1959 ・・ 30.
It seems to be grown well in spite of rather unsuitable site. Initial 3 treatments of seedlings seem to be not so effective to the growth, but it was generally observed that trees grown larger on the lower benches than on the upper ones. This is due to the differences of physical properties of the soil, perhaps.