• Journal of Ecology and Environment
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• v.42 no.4
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• pp.155-162
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• 2018

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.693-702
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• 2015

The objective of this study is to investigate and evaluate that a roadside tree root intrudes sewer network systems. Two approaches were performed to assess the characteristics of tree root intrusion. First, the characteristics of tree roots that had invaded sewers were directly observed by means of closed-circuit television inspection robot. Second, the intrusion proportions of tree root into rain gutters in the sampling area were investigated. As tree species of low intrusion proportions, the results indicated that Ginkgo biloba Linn. and Acer buergerianum Miq. were 1.7% and 4.3%. On the other hand, tree species of high intrusion proportions were Metasequoia glyptostroboides Hu et Cheng, Ulmus davidiana var. japonica Nakai and Zelkova serrata Makino as 22.2%, 20.4%, and 17.6% respectively. In particular, sewers and gutters around Zelkova species should be the focus of maintenance work because of the high proportion of these trees on roadsides.

• ETRI Journal
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• v.23 no.3
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• pp.111-120
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• 2001

For scalable multicast transport, one of the promising approaches is to employ a control tree known as acknowledgement (ACK) tree which can be used to convey information on reliability and session status from receivers to a root sender. The existing tree configuration has focused on a 'bottom-up' scheme in which ACK trees grow from leaf receivers toward a root sender. This paper proposes an alternative 'top-down' configuration where an ACK tree begins at the root sender and gradually expands by including non-tree nodes into the tree in a stepwise manner. The proposed scheme is simple and practical to implement along with multicast transport protocols. It is also employed as a tree configuration in the Enhanced Communications Transport Protocol, which has been standardized in the ITU-T and ISO/IEC JTC1. From experimental simulations, we see that the top-down scheme provides advantages over the existing bottom-up one in terms of the number of control messages required for tree configuration and the number of tree levels.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.92-104
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• 2002

This study investigates, analyzes, and summarizes Dansplantation techniques and methods through practical methodology centering on fieldwork in order to present effective planting methods for large trees that have important significance. The conclusions are as follows : 1. The transplantation process of a large tree generally consists of the stages of digging up a tree, manufacturing a carrier frame, loading the tee on a vehicle, transporting, transplanting the tree, installing a strut and maintaining and managing the new transplant. In addition, planting a tree on a mounted place includes the primary procedures of trimming out the root, and preparing for transplanting the tree on a mounted place, as well as the secondary work of trimming out the root, transplanting a tree on a mounted place, maintenance and management. 2. In order to decide on a transplantation method for a large-sized tree, a structure calculation has to be performed first. That is, one must calculate the weight of the tree and the allowable stress of the strut (H-beam, etc.) fhst and then decide on the upper method through computer modeling based upon this structural calculation. 3. As a result of the analysis of a transplanted tree using the life soil method, it was confirmed that large quantities of feeder roots had developed around the root within a short time after the transplantation. The life soil method has proven to be very effective for transplantation of large-sized trees. 4. As for the production method of an H-beam strut frame, it was found that the manufacturing process and disassembly process were simple and proper; therefore, the H-beam frame is an appropriate structure to be used in the transplantation of large trees. 5. The concavo-convex method, which consists of filling the life soil in the concavo-convex area around the root, was found to be a method that promotes the growth of feeder roots within a short period of time and saves the supply of water at the same time.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.131-140
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• 2014

In this paper, we present an efficient implementation of Kruskal's algorithm to obtain a minimum spanning tree. The proposed method utilizes the union-find data structure, reducing the depth of the tree of the node set by making the nodes in the path to root be the child node of the root of combined tree. This method can reduce the depth of the tree by shortening the path to the root and lowering the level of the node. This is an efficient method because if the tree's depth reduces, it could shorten the time of finding the root of the tree to which the node belongs. The performance of the proposed method is evaluated through the graphs generated randomly. The results showed that the proposed method outperformed the conventional method in terms of the depth of the tree.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.36-45
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• 2004

This study was conducted to formulate management guidelines for monumental old trees in Korea through analysis of growing environments. A total of 20 old trees designated as natural monuments in Seoul, Incheon, and Gyeonggi provinces were surveyed for biological characteristics, surrounding environments, root collar conditions, tree health, and soil characteristics. Relationships among root collar conditions, tree health, and soil characteristics were analyzed by correlation. The old solitary trees designated as natural monuments included Pinus bungeana(4 trees), Juniperus chinensis(3 trees), Ginkgo biloba(3 trees), Poncirus trifoliata(2 trees), Actinidia arguta, Wisteria floribunda, Thuja orientalis, Quercus variabilis, Sophora japonica, Fraxinus rhynchophylla, Zelkova serrata, and Pinus densiflora. The tree height ranged from 3.56 to 67m, and root collar diameter ranged from 1.01 to 15.2m. The monumental old trees were growing on the various sites ranging from gardens, historical sites, open agricultural fields, mountain hills, to near the ocean beaches and streams. The coverage of bald land ranged from 50 to 100%, and depth of filled soil around the root collar ranged from 0 to 50cm. Tree health was expressed as the amount of branch dieback, cavity development, detachment of cambial tissue, infliction by diseases and insects. The branch dieback ranged from 5 to 20%, cavity development ranged from 10 to 100$cm^3$, detachment of cambial tissue ranged from 5 to 45%, and infliction by diseases and insects ranged from 5 to 20%. Soil pH ranged from 5.9 to 8.3, organic matter contents from 12 to 56%, phosphorus contents from 104 to 618ppm, while soil compaction ranged from 7 to 28mm. Results of correlation analysis showed that coverage of bald land was the most serious factor to deteriorate the cavity development and detachment of cambial tissue. In addition, chemical properties of soils seemed to be related to the health of the trees.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.59-70
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• 2021

This study was to investigate the measurement point of root collar diameter of landscape trees in Korea. It may contribute to avoiding disputes caused by the difference in measurement criteria of root collar diameter of landscape trees between tree growers and constructors. The difference between landscape trees' root collar diameter measurement point was 3.59cm from 6cm underground to the surface and 1.35cm from 0cm to 6cm above ground. The source root collar diameter measurement point difference was larger in the basement than in the ground. The standard deviation of the root collar diameter of the landscape tree was 0.64 from 6cm underground to the surface, and the difference in standard deviation from 0cm to 6cm above ground was 0.16. The difference by measurement point of the root collar diameter was larger in the basement than in the ground. It has been proposed to set the reasonable measurement point of the landscaping tree root collar diameter at the inflection point where the standard deviation of the tree trunk diameter is the smallest in line with the size change of the standard for each root collar diameter measurement point. By tree species, Cornus officinalis Siebold & Zucc. 18cm above the ground, Chionanthus retusus Lindl. & Paxton. 12cm above the ground, Zelkova serrata (Thunb.) Makino. 12cm above the ground, Celtis sinensis Pers. 12cm above the ground, Styrax japonicus Siebold & Zucc. 10 cm above the ground, Cornus officinalis Siebold & Zucc. 10cm above the ground, Acer palmatum Thunb. ex Murray. 6cm above the ground, Ilex rotunda Thunb. 6cm above the ground, Quercus myrsmaefolia Blume. 4cm above the ground, Lagerstroemia indica L. 2cm above the ground The above heights were shown as reasonable measurement points. The difference by landscape tree root collar diameter measurement site showed that the standard deviation was small throughout the tree species, and the reasonable average measurement point with a stable slope of the deviation was 12cm or more on average. It can be said that the reasonable measurement point of the root collar diameter of a landscape tree is set at an average of 12cm above the ground. However, recognizing 30cm, which is a familiar ruler(尺) in traditional practices, is quick, It was recommended to measure at the height of 30cm from the surface for a reasonable measurement point of the root collar diameter of a landscape tree, for the uniformity of measurement standards.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.572-575
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• 2011

It is well known that spanning tree protocol (STP) is the most commonly used protocol in switching networks for smart grid. STP selectively blocks redundancy links of the network to prevent layer 2 loops in network, and it also has a functionality of backing up links. As with the other protocols, STP has been updated with the continuing development of the network. STP is a broad concept and it does not just refer in particular to defined STP protocol in IEEE 802.1D standards, it refers to updated spanning tree protocol based on STP. Because of uneven distribution of communication traffic in root bridge, STP cannot satisfy fast converge nce while the failure occurs near the root bridge or on the root bridge in tree topologies of STP. In this paper, we propose a novel method --- Hyper Cube Spanning Tree Protocol (HCSTP) to solve uneven distribution of communication traffic. Theoretically, hyper cube in our protocol increases throughput and improves the utilization of communication. The simulation results show that HCSTP can achieve comparative and considerably higher performance than other STP protocols in terms of reconnection.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.422-425
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• 2002

Application of biostimulants, humate-based products marketed as aids to plant establishment, may increase root growth of turfgrass and maple tree. We tested three types of biostimulants on root growth of creeping bentgrass (Agrosfic palustris Huds.) and maple (Acer rubrum L.). Roots were first observed in the 2-3 weeks after treatments. Biostimulant-treated tufgrass and tree had more root length than nontreated controls. Turfgrass nutrient absorption was increased with biostimulant application.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.5
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• pp.28-39
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• 2003

This study was carried out to elucidate effective restoration measures for natural forest with recycling native tree un site from November 2001 to October 2002 to obtain a basic information for revegetation measure, eight experimental treatment was done and the length of stump, root-ball size of stump, antisepsis treatment of trunk cut, Planting season and contents of organic matter in soil were effective on regrowth of root-stock. Thirteen tree species including Quercus acutissima among twenty tree species showed outstanding sprout and survival rate(over 90 percent), Planting in November and combinated planting with 5 trees and 9 shrubs of root-stock per 100$m^2$ plot showed a good growth. And 10 percent of organic matter plot showed a good crown coverage.