ABSTRACT

Despite their potential usefulness as a natural resource, wild edible bamboos tend to be ignored or neglected by foresters, and we know little about how environmental factors determine the productivity of edible culms. Here, to examine determinants for the productivity of edible culms of Sasa kurilensis, 60 survey plots were established in a northern Japanese forest, and annual field surveys were carried out over 3 years. The results show that the density and stem diameter of edible culms were determined by the local density and stem diameter, respectively, of old culms. This indicates that we can predict how many and what kind (thickness) of edible culms will be produced based on information about the demographic properties of old culms. Then, by using the GIS-linked data, the environmental factors that affect the demographic properties of old culms were explored. As a result, slope angle was the most influential environmental factor; that is, the density of old culms decreased but the stem diameter increased along the gradient of increasing slope angle. This indicates that the productivity of valuable culms in flat areas may be low since edible culms with small stem diameter are less valuable for eating. To confirm this, the productivity of valuable edible culms, which have a basal diameter larger than a specified thickness was estimated at each site, and a hump-shaped relationship between productivity of valuable edible culms and degree of slope angle shows that the productivity of valuable edible culms can be maximized at medium slope angle.

摘要

尽管野生食用竹作为天然资源具有潜在用途，但往往被林务员忽略或忽视，我们对环境因素如何决定食用菌的生产力知之甚少。在这里，检查决定因素的Sasa kurilensis食用菌的生产力，在日本北部的森林中建立了60个调查区，并在3年​​内进行了年度实地调查。结果表明，食用茎的密度和茎直径分别由老茎的局部密度和茎直径决定。这表明我们可以根据有关旧茎的人口统计特性的信息，预测将生产多少根，多少根（厚度）的食用茎。然后，通过使用GIS链接的数据，探索了影响老种人口统计特性的环境因素。结果，倾斜角是影响最大的环境因素。也就是说，老茎的密度下降，而茎直径随着倾斜角的增加而增大。这表明，由于茎直径较小的可食用茎对食用的价值较低，因此在平坦区域中有价值的茎的生产率可能较低。为了证实这一点，估计了每个位置的基径大于指定厚度的贵重食用菌的生产率，并且贵重食用菌的生产率和倾斜角度之间的驼峰形关系表明了贵重食用菌的生产率。可食用的茎秆可以在中等倾斜角度下最大化。