Factors influencing the distribution of two co‐occurring dwarf bamboo species (Sasa kurilensis and S. senanensis) in a conifer‐broadleaved mixed stand in northern Hokkaido

Abstract

Factors influencing the distribution of two co-occurring dwarf bamboo species (Sasa kurilensis and S. senanensis) in a conifer-broadleaved mixed stand in northern Hokkaido Abstract We have investigated the factors influencing the distribution of co-occurring two dwarf bamboo species, Sasa kurilensis (Ruprecht) Makino et Shibata and S. senanensis (Franchet et Savatier) Rehder, within a conifer-broadleaved mixed stand managed with selection cutting in northern Japan. We first sought the possible determinant factors (physical environment and overstory conditions based on 30 years' tree census data) deciding the dominant species in the plots (168 3.14m 2 area). We then examined the effects of these factors on the culm density and height of the dominant species. Linear discriminant analysis indicated that physical environmental conditions are important in determining the distribution; S. kurilensis tended to dominate plots with steep slope, convex shape and deep snow in early spring. Multiple regression analyses showed that culm density and height decreased significantly on steep slopes for both species. Also, the sum of the basal area (BA) of surrounding conifers (7.5 m radius around the plot), as well as the change in BA over the previous 30 years, had a negative influence on the culm height of both species. A reduction in overstory trees, caused by natural or artificial canopy disturbances, would increase the dwarf bamboo biomass. The effects of physical environment and overstory conditions, working through the dominance of the two dwarf bamboo species, should be taken into account in understanding the dynamics of natural forests in this region.

Relationships between the Abundance of Abies sachalinensis Juveniles and Site Conditions in Selection Forests of Central Hokkaido, Japan

“…Previous studies have shown that Abies regeneration rates are higher on south-facing slopes (Yamamoto et al, 1995) where there is typically a higher heat load index (Hosaka et al, 2008). These factors may have no relevance to the distribution of dwarf bamboo, as they are not significant determinants of culm density (Noguchi and Yoshida, 2005). Local topography may be indirectly associated with the pathogenic fungus Racodium therryanum (or Herpotrichia juniperi ), which is another significant factor inhibiting natural regeneration in Hokkaido (Cheng and Igarashi, 1990).…”

“…Because dwarf bamboo negatively affects the density of Abies seedlings in selection forests (Hosaka et al, 2008;Nakagawa and Kurahashi, 2005;Noguchi and Yoshida, 2005), shading from overstory trees most likely led to increased abundance of Abies juveniles. Slope angle is also correlated with the density of dwarf bamboo undergrowth, which significantly decreases on a steep slope (Noguchi and Yoshida, 2005;Hosaka et al, 2008).…”

Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

“…The volume of understory vegetation was also more abundant in the managed stands. The quantity of dwarf bamboo, a dominant understory species in the study site, often correlates negatively with the volume of overstory trees [30], and rises after disturbance. Nonetheless, the overall difference between stands was small, and there was no significant difference in species diversity among understory vegetation (Table 3).…”

Effects of Site Factors on the Clonal Growth of Phyllostachys bambusoides f. shouzhu Yi

“…Phyllostachys bambusoides f. shouzhu Yi is a bamboo species belonged to Bambusoideae of Gramineae [1,2], and mainly distributed in Sichuan and Chongqing, Southwest China [3]. As its bigger diameter at breast height (DBH)(up to 13cm) and its longer internode (up to 60 cm), the species is planted on a commercial scale for the large culms, and are widely used for building materials, farm tools, and furniture and are also split for weaving various bamboo articles.…”

“…Knowledge on the morphological features and biomass is necessary for estimating the bamboo productive forces and improving the silvicultural level, and its result may be used in guiding the forestation and usage of bamboos [13]. However, little is known about the site factors in luencing the clonal growth of P. bambusoides f. shouzhu [3,14]. In view of the signi icantly economical and ecological functions of P. bambusoides f. shouzhu, an explanation of its clonal growth in forest would be helpful in improving the forestation of bamboo forests in the region.…”