アカマツ林土壌における糸状菌の分布に関する研究(第4報) : 針葉と広葉の糸状菌群落におよぼす影響

The influence of pine needles and broad-leaves which constituted pine forest litter on the micro-fungus flora was investigated.
Leaves fallen last autumn and having no visible change were collected from pine forest floor in spring. The pine needles and broad-eaves were mixed in the following ratio on the basis of fresh weight : needles 100 g; needles 70 g + broad-leaves 30 g; needles 50 g + broad-leaves 50 g; needles 30 g + broad-leaves 70 g; broad-leaves 100 g. Five litter bags with each mixture were exposed on F layer of pine stand After 374 days, bags were brought into the laboratory for measurement of fungal counts, moisture content and loss of weight. The micro-fungi were isolated by dilution plate method.
In contradiction to the general tendency, the loss of weight of broad-leaves was least (Table 1).
Fungi isolated from each sample are shown in table 2. Fungal counts per gram of oven-dry litter were higher in broad-leaves than in pine needles. The rate of increase of fungal counts was in proportion to the ratio of broad-leaves in mixture (Fig. 1).
Concerning the species isolated, there was no difference between pine needles and broad-leaves, but in quantity the difference was apparent. The species such as Papularia spp., Sphaeropsidales, and dark sterile mycelium which belong to TYPE 1 of the vertical distribution patterns of soil fungi were dominant in pine needles. On the contrary, Mucor ramannianus, Mortierella spp., Trichoderma viride, Penicillium spp. and Cephalosporium sp. W 1 belonging to TYPE 2 were abundant in broad-leaves (Table 3).