Twenty years of community dynamics in a mixed conifer – broad-leaved forest under a selection system in northern Japan

Abstract

Single tree selection has been employed widely in northern Japanese mixed forests, but management-induced changes in forests are not been well understood. This study examined demographic parameters of major tree species during 20-years in a 68-ha study stand, in which single tree selection has been conducted since 1971. Results showed that conifers (mostly Abies sachalinensis) gained the strongest positive effects from the treatment on growth and survival.Nevertheless, recruitment of conifers was not sufficiently improved, suggesting their decreased dominance over a longer-term. Instead, shade-intolerant broadleaved (mainly Betula ermanii) will gradually increase because of their higher recruitment rates after the treatment. Shade-tolerant broadleaved (mainly Acer mono and Tilia japonica) appeared to experience the most distinct negative effects, especially on survival. These trends differed markedly from those reported in previous papers concerning partial harvesting system, which predicted increase of shade-tolerant species. The results shown here should be generalized carefully because we have investigated only one stand without repetition of the control area. Nevertheless, trends described in this large-scale and long-term study could provide a basis for simulating stand dynamics. We discussed possible reasons for the observed patterns, and provided implications for sustainable management in the region.

Individual growing conditions that affect diameter increment of tree saplings after selection harvesting in a mixed forest in northern Japan

“…This 110 ha forest consists of ten harvesting compartments and one control compartment, and our study stand was one of these harvesting compartments. Each compartment has been managed with a selection-harvesting system since 1967 at approximately 10-year intervals (one compartment per year) (Ohgane et al 1988;Yoshida et al 2006). Harvesting before 1967 was negligible, reflected in the very limited number of corresponding cut stumps (Yoshida et al 2006).…”

“…In Hokkaido, a northern island of Japan, many natural uneven-aged mixed forests have suffered degradation of their stand properties, including tree density and size structure, with selection harvesting (Nagaike et al 1999;Yoshida et al 2006). This degradation has been exacerbated by the dense dwarf bamboo understory, which hinders establishment of tree species (Nagaike et al 1999;Umeki and Kikuzawa 1999).…”

“…This degradation has been exacerbated by the dense dwarf bamboo understory, which hinders establishment of tree species (Nagaike et al 1999;Umeki and Kikuzawa 1999). In a stand managed with a single-tree selection system, Yoshida et al (2006) found that the recruitment rates of many component species to subcanopy layer were very low, suggesting that more careful management is required to ensure regeneration. A subsequent study (Noguchi and Yoshida 2007) also suggested that many saplings (DBH \ 12.5 cm) were distributed in small harvest gaps that could be readily closed.…”

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

“…In Hokkaido, Northern Japan, the selection system has been used since the early 20th century to manage cool-temperate and subboreal mixed forests (Yoshida et al, 2006).…”

Using Global Positioning System (GPS) Technology for Tree Marking in a Natural Forest under a Single-Tree Selection System (GPS)

“…In comparison to even-aged silvicultural systems, a relatively steady state of stand structure and ecosystem functions can be maintained over time (O'Hara et al, 2007). Singletree selection has been widely used in Hokkaido, Northern Japan, since the early 20 th century as the preferred option for natural forest management (Yoshida et al, 2006).…”