In logged-over forests, altered light conditions with logging induce pioneer species invasion and reduce commercial value. In Indonesia, reduced impact logging (RIL) methods have been applied to mitigate the logging effects, and line planting of useful species has been conducted in some production forests. However, quantitative assessments of canopy openings during RIL and line planting treatment are insufficient. Line plating involves 3-m strip cutting lines. The effects of these methods on canopy openness are poorly understood. This study assessed the effects of different logging systems on light conditions using hemispherical photographs taken in plots set in primary forests, forest logged over using RIL, and forest treated with strip cutting after RIL. Photographs were also taken along strip cutting lines. The comparison of canopy openness among the three types of sites revealed that logging activities had significant effects on light condition. High levels of canopy openness were found along skid trails and logging gaps following the trails. Therefore reducing the impact on light conditions should be considered when planning skid trails. Between the logged-over forest plots with and without the strip cutting lines, there was no significant difference in the mean canopy openness. However, strip cutting treatment affected to sun fleck duration in the forest floor. It might influence to following dynamics. And there were large differences in canopy openness along each line which would cause variations in the growth of planted trees.

We monitored changes in light conditions at a primary forest and two managed forest sites (one with line planting) after reduced-impact logging in Central Kalimantan, Indonesia. We also assessed the effect of the light conditions on seedlings in the planting lines. Hemispherical photographs were taken over a period of months in three 50 × 50-m quadrats at each site and in three 100-m transects along the planting lines. The location of each photo was categorized according to the corresponding type of disturbance, including skid trails, logging gaps, and planting lines. Following logging, the level of canopy openness (CO) increased at both managed forest sites and did not differ significantly between the two. However, CO was greater in skid trails and logging gaps than in planting lines. After 31 months, the mean level of CO at each managed site had decreased significantly due to the establishment of new seedlings. Correlations between changes in CO and the growth of planted seedlings suggested that growth was inhibited by the invasion of the new species. However, the level of CO along the planting lines was greater than that at other disturbed locations. A high level of CO promoted invasion by new species that colonized the space. Line planting may influence forest dynamics and maintain a high level of CO.

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In Indonesia, in recent years, line planting of valuable Shorea species has taken place on logged forest to maintain the timber yield. However, there exists scant information about the effectiveness of such a method. Neighboring trees along the planting lines affect the planted trees. We assessed the survival, growth, and crown exposure of the planted trees to evaluate the effect of neighboring trees in three 1 ha-monitoring plots, in which Shorea johorensis seedlings had been planted at a 5-m spacing along five parallel lines separated by 25 m, all running in a north-south direction within a 3 m-wide strip. The planted trees were monitored for 11 years after planting. The crown exposure was evaluated using a three-dimensional spatial structure model and SExI-FS software. Eleven years after planting, 77.6 % of the planted S. johorensis had survived. The average diameter at breast height (DBH) was 16.7±5.6 cm, ranging widely from 5.3 to 33.6 cm. The initial growth 1 year after planting predicted the variance in DBH 11 years later. Trees showing rapid initial growth exhibited higher survival and subsequent growth rates. The variation in light conditions in the planting lines affects the growth and survival. The spatial structure model illustrated how neighboring tree crowns suppress the growth of the planted tree by casting shade. In a line-planting system, the neighboring tree effect influences the survival and growth of the planted trees, and this can be reduced by treatment of the canopy to ensure exposure of planted trees to sunlight.

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