• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.67-76
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• 2019

With an increasing demand of timber production, the use of heavy machinery in forest management has significantly increased, causing the changes of soil physical properties and the decline of long-term site productivity. This study was conducted to evaluate the effects of logging slash (non-slash, slash $7.3kg/m^2$, and slash $11.5kg/m^2$) and machine passes(harvester 1 pass and forwarder 1 to 10 passes) on soil physical properties at 10 cm, 20 cm and 30 cm soil depths in harvester and forwarder operations and also to estimate the degree of soil surface disturbance. The results indicated that soil bulk density in the non-slash treatment site increased 10 %~29 % (25~139 % in soil penetration resistance) at all soil depths, compared with the slash treatment site(slash $11.5kg/m^2$). Therefore, the creation of a slash mat could be an effective way to minimize the changes of soil physical properties. In addition, 92 % of total soil compaction in slash treatment site was created within harvester 1 pass and forwarder 5 passes. In non-slash treatment site, 84 % of total soil compaction was created within first harvester and forwarder passes. The results showed that slash treatment was effective to reduce soil compaction caused by machine passes and also it is necessary to create designed forwarding trails for minimizing soil compaction area at timber harvesting sites.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.2
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• pp.41-63
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• 2022

The purpose of this study is to secure objective and precise data through ecosystem monitoring, to reveal ecological characteristics through comparison and analysis with past survey data, and to accumulate basic data for diagnosing the current situation and predicting changes in the ecosystem. The target site is the 'Quercus mongolica forest on the Buksa-myeon of Namsan', which was designated as an Ecological Landscape Conservation Area (ELCA) of Seoul in July 2006. The research contents are analysis of soil environment change (1986~2016), change of actual vegetation (1978~2016), and change of plant community structure (1994~2016). A total of 8 fixed surveys (400~1,200m²) were established in 1994 and 2000. Analysis items are importance value, species and population, and Shannon's species diversity. The soil environment of Namsan is acidic (pH 4.40 in 2016), which is expected to have a negative impact on tree growth and vegetation structure due to its low capacity for exchangeable cations. Quercus mongolica forest in Namsan is mainly distributed on the northern slopes. The actual vegetation area changed from 49.4% in 1978 → 80.7% in 1986 → 82.4% in 2000 → 88.3% in 2005 → 88.3% in 2009 → 70.3% in 2016. In 2016, the forest decreased by 18% compared to 2009. While there was increased growth of Quercus mongolica in the tree layer from 2009 to 2016, the overall decline in vegetation area was due to logging and fumigation management following the spread of oak wilt in 2012. As for the changes in the plant community structure, Quercus mongolica of the tree layer was damaged by oak wilt, and the potential vegetation that can form the next generation was ambiguous. In the subtree layer, the force of urbanization tree species such as Styrax japonicus, Sorbus alnifolia, and Acer palmatum. was maintained or increased. In the shrub layer, the number of trees and species increased significantly due to the open tree crown, and accordingly, the species diversity of Shannon for woody plants also increased. In Quercus mongolica forest of Namsan, various ecological changes are occurring due to the effects of urban environments such as air pollution and acid rain, the limitation of Quercus mongolica pure forest due to oak wilt, and the introduction of exotic species, thus, it is necessary to establish a management plan through continuous monitoring.