Forest operational planning is normally based on stands, owners or regional level as the primary unit of treatment. A forest landscape is a spatial mosaic of arbitrary boundaries containing distinct areas that functionally interact. Landscape structure refers to the relative spatial arrangement of patches and interconnections among them. In recent years, interest has been directed towards the use of smaller area units such that the formation of treatment units becomes part of the operational planning. This study explored the implementation of a multi resolution segmentation approach to site qualify and stocking level estimation using an object-oriented eCognition and discussed the applicability of the proposed system to costal forest management.

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Japanese forests have been managed precisely by administrations using forest inventory data. However, the change of the circumstances surrounding plantation forestry is causing degradation in timber value and devastation of forests, especially because of the lack of tending and thinning operations according to management plans. Increase of an unkempt stands, which causes breakdown or destruction of overall forests. A forest administration is to keep the archive record of tending condition in spatial extent, however identification of the tending condition is now implemented by means of direct ground surveying, which is time and cost consuming manner to figure out the objective trees from wide forest area. In this study, the authors proposed the object-oriented segmentation method based on canopy density distribution using high resolution satellite images of IKONOS in term of automatically detecting the target tree for thinning on regional scale of plantations forests.

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It is necessary to know forest composition for preservation of a coastal forest. In the Kujuukuri coastal forest, we analyzed the relation between forest composition and ALOS PALSAR data by the multiple regression analysis method. As a result, in order to know forest composition, we found out that HV polarization is more effective than HH polarization. We showed that it was effective in using SAR data to analyze the stand density of a coastal forest.

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We investigated sediment yields from yarding roads and their grain size characteristics, and studied the effect of differences in geology on yarding and forest roads. The study site included yarding roads within an abandoned former plantation forest that had been clear-cut, located near Kuma-mura, Kumamoto Prefecture, Japan. The geology of the study site consists of sedimentary rocks. To clarify sediment yields from yarding roads and grain size characteristics of the sediment yield, two experimental catchments were installed. Yearly sheet erosion rates in R1 (experimental catchment with an 86-m² area and 8° average slope) and R2 (experimental catchment with a 111-m² area and 6° average slope) were about 3.3 mm and 0.9 mm, respectively. These rates were about 33% and 9%, respectively, compared to those measured in a weathered granite catchment. The reason for this difference is that cohesion in sedimentary rocks was greater than that in weathered granite. The median grain diameter for individual sediment yields in R1 was between 0.27 mm and 0.75 mm, and for R2 was between 0.67 mm and 5.45 mm. Grain size distributions of sediment yields in R2 were variable in comparison with grain size distributions of sediment yields in R1.

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We investigated the current vegetation conditions on Shirasu steep slopes susceptible to shallow landslides, and particularly the role of root networks and topsoil in preventing shallow landslides, in abandoned forests 4 years after plantation clear-cutting. The study area was located near Kagoshima Airport, Kagoshima Prefecture. To conduct vegetation surveys and take topsoil thickness measurements, we established quadrats on seven slopes: five with steep slopes (>40°) and two with relatively gentle slopes (30°). Vegetation on the steep slopes prone to shallow landslides was less abundant than that on the relatively gentle slopes. If there is no reforestation after clear cutting on steep slopes, vegetation recovery is substantially delayed in comparison with that on reforested slopes, and recovery of the role of forest root networks to prevent shallow landslides is substantially delayed. Moreover, the average value of topsoil thickness on the steep slopes was approximately 40 cm. Based on the relationship between shallow landslide occurrence and topsoil development, this value of approximately 40 cm indicated that shallow landslides could be expected to occur.

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From the mid-1980s until 1997, Japanese black pines growing in the Fukiage sand dunes were devastated by pine wilt disease. We investigated the characteristics of the blown sand mass as well as the recovery conditions and growth environment of coastal forest 13 years after this forest mortality. We placed three 250-m transects (Transects 1–3) perpendicular to the shoreline from the top of the fore-dune to the inland area. Transects 1 and 2 were in areas of black pine forest that had been severely damaged by pine wilt disease, and Transect 3 was in an area that was almost undamaged. We investigated the spatial distribution of the blown sand mass and conducted vegetation and soil surveys along the three transects. The blown sand along Transects 1 and 2 originated from the fore-dune and had moved approx. 200 m inland, while that along Transect 3 was restricted to the area around the fore-dune because of a protective forest that provided a barrier against blown sand. The coastal forest in Transects 1 and 2 was poorly developed compared with that in Transect 3. Artificial formation of coastal forest in the frontal (fore-dune) area is necessary to protect forests and to allow regeneration.

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A traditional Feng Shui village landscape in Okinawa features multilayered forest belts closely surrounding the habitat. Fukugi (Garcinia subelliptica) trees, Ryukyu pines and other native species were planted to protect the hamlet and the island from strong winds. Among these species, Fukugi distinguishes itself as being long-lived and strong against typhoons and monsoonal winds. Through surveying the distribution of huge remnant Fukugi trees in the old hamlets, this study is to explore when and how such a Feng Shui hamlet was built and the layout that is still a mystery to historians, and further probe into the cultural and historical significances of Fukugi. Through this survey of total 183 hamlets throughout Okinawa Gunto, mainland Okinawa and its nearby 16 small isolated islands, we found that about one third of all surveyed hamlets had huge trees older than 250 yrs., and these hamlets were distributed in a wide area not only on mainland Okinawa but also on the isolated islands. The estimated age of the biggest Fukugi was about 373 yrs. old. Besides, around the houses, Fukugi trees were also found to have been planted around sacred sites and the old public offices. Thus, such traditional hamlets can date back to the 17th Century, and may have been wide-spread throughout Okinawa Gunto since the early half of the 18th Century. All existent huge Fukugi trees were purposely planted. From the standing locations of Fukugi trees around the human habitat, around sacred sites, and even public office sites, it is obvious that the Fukugi tree was considered as an auspicious tree species besides being a useful and strong species.

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