Aiming to clarify the mechanism of beech forest declines on the Tanzawa Mountains, we conducted field surveys on such three hierarchic spatial scales as macro, meso and site. Then we quantitatively analyzed forest structure and the recent state of decline. Macro-scale survey showed that the ratios of tall beech in forests are less than 30 % in number and beech forests were classified into three types. Also beech declines have progressed on ridge lines above 1400 meter elevation and the western parts of Tanzawa as well as northern part of Eastern Tanzawa were not observed significant damage. Forests at high altitudes and flat terrain were suffered more serious decline. Declines also progressed at forests on higher solar radiation and lower soil water index. Field surveys around the top of Mt. Tanzawa and Mt. Hinokiboramaru, where declines are relatively serious, indicated that forest facing south to west suffered serious damage. Also a site scale survey on several specific forests where declines remarkably progressed showed not only massive tall beech damage but also less vigor even for other tall trees. Based on the observational study above mentioned we discussed spatially hierarchic relations of beech decline causes and then sort out research priorities.

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The spatial pattern of landscape patches in forest area has been becoming clearer to have much effect on habitat distribution, thus landscape analysis is needed for conservation of biodiversity. Recently, abandoned private plantation forests have been ranging widely, and biodiversity loss in the forest landscape derived from enlarging unsuitable spatial pattern for habitats in addition to decline in quality within patches has been apprehended. This paper aimed at showing effects of the spatial pattern of plantation landscape structured through forest management on biodiversity. We simulated the spatial pattern structuring based on scenarios of 3 different thinning plans. Then we considered effectiveness of each spatial pattern changes structured based on scenarios in chronological order on biodiversity, measuring shape, density, nearest neighbor distance and splitting index of forest stand patches which were different manage ranks. As a result, both forest managements according to 2 actual thinning policies were seemed to be effective on conservation of biodiversity, while we could not show more effective management between them.

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The analysis of spatial pattern of biodiversity hotspots is an effective approach for deliberation of conservation strategy of biodiversity. On Tanzawa Mountains faced crisis of biodiversity, such as beech forests declines and overabundance of sika deer, we examined spatial patterns of hotspots and discussed an effective strategy for conservation of biodiversity. We extracted four kinds of hotspots from two aspects, distribution of flora (richness, rarity, and endemism hotspots) and habitat change (habitat hotspots), using flora database collected by systematic sampling and landuse data in 1976 and 1997. We analyzed the spatial autocorrelation using the Moran's I and the overlaps among the hotspots area. In addition, we conducted the Gap analysis between the hotspots and special protection area of quasi-national park. In the results, there are no spatial autocorrelations and spatial patterns on the distribution of all hotspots and these indicated that both high and low biodiversity area is scattered in Tanzawa Mountains. Only 12.3% of the flora hotspots are common to the three kinds of flora hotspots (richness, rarity, and endemism hotspots). These suggested that we should evaluate the hotspots of biodiversity using the different aspects. Moreover, as the results of gap analysis, we found that high biodiversity area (richness, rarity, and endemism hotspots) is distributed in both the inside and the outside of the special protection area of quasi-national park. The special protection area is effective for conservation of biodiversity, but it is insufficient only in the present area. We concluded, for conservation of flora diversity, that the need to use multiple indices of biodiversity in identifying areas of high conservation priority.

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It is hoped that the Higashimachi district of the Shonan coast will become a significant habitat for coastal plants due to the increasing vegetation area as a result of shoreline advancement. Therefore, this study focused on the migration distance by thalassochory and the composition of drift seeds and existing vegetation to discover the source of seed supply for the Higashimachi district. We released seeds of Tetragonia tetragonoides from five sites and measured the migration distance of the seeds. The composition of drift seeds was examined in the tidal drifts at the Higashimachi district. It was difficult for dispersal of submerged seeds by sea currents to migrate from the Koyurugi and the Tsujido West district of rich coastal vegetation to the Higashimachi district, because the migration length of seeds was short. At the same time, it was found that the migration length of seeds in the mouth of the Hanamizu River was long (maximum 1180m). Therefore, it was possible for dispersal of submerged seeds by sea currents to migrate from the periphery of the mouth of the Hanamizu River to the Higashimachi district. As a result, it was considered that the source of seed supply for the Higashimachi district differed according to the buoyancy period of seeds of the different coastal plants. In addition, it was found that there were 56 species of drift seeds and only five species of coastal plants, such as Carex kobomugi, Calystegia soldanella. These five species were seeds that could float on sea currents for long periods, and were present in the existing vegetation of the Higashimachi district. Consequently, it is considered important to take into account the influence of seed supply from the periphery by thalassochory in order to restore coastal vegetation at the Higashimachi district.

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Bird communities as an indicator of biodiversity for evaluation of a river ecosystem were surveyed in the riparian stripe zone of the Abukuma River. In addition, landscape factors, including anthropogenic disturbance, were analyzed in order to determine the relationship between bird communities and these factors. The survey area was divided in fifty-five plots according to the continuous landscape elements. At each plot, summer bird communities were grouped into five and water bird communities and terrestrial bird communities in winter were each grouped into four. The number of bird species at each plot had a strong positive correlation with the number of natural elements of landscape factors and transverse distance, and there was a negative correlation with the gradient of the river embankment. The diversity index had a strong positive correlation with transverse distance. Nine bird species in the summer survey and two terrestrial bird species in the winter survey were selected out of the respective classified groups which showed highest values of correlated landscape elements with the integrated multivariate analysis, including a gap analysis. Destruction and degradation of riparian ecosystems have been continued by human activities. However, some of the detrimental effects of anthropogenic disturbance on riparian ecosystems can be minimized with proper planning. Three important landscape elements suggested in this study can be taken to conserve riparian ecosystems. To minimize development in and along floodplains, it is necessary to keep the transverse distance › 100m, incorporate gentle gradient embankment, and maintain the number of such natural landscape elements as vegetation and gravel.

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The mountain hawk-eagle (Spizaetus nipalensis) is an endangered and an umbrella species ranking high in the food chain of the forest ecosystem. The objective of this study was to estimate the potential habitat of the mountain hawk-eagle in Yamagata prefecture, northern Japan. Habitat suitability of each grid was estimated using values of indices corresponding to terrain and vegetation features of the surroundings. Previous studies have computed terrain indices such as minimum and mean altitude and mean slope gradient within each grid-square of approximately 5km in size. To estimate potential habitat more accurately, we used 13 terrain and vegetation indices, including the valley distribution index that is important for the mountain hawk-eagle, and set a grid resolution of 50m to describe potential habitat map at fine scale. Since these indices would be sensitive to the analyzing window size placed around each grid, we examined this effect by changing radii as 0.5, 1, 2 and 3km. Values of these indices were computed in each grid with a 50m digital elevation model (50m DEM) and a rasterized 1/50,000 digital vegetation map. By comparing Akaike’s Information Criterion (AIC) values and accuracies among logistic regression models with different combinations from a set of 13 indices, an optimal model with the lowest AIC value and high accuracy was determined. The model used the distribution of valleys within 1km radius and the area of forest within 3km radius, which indicates the importance of valleys and forest for the mountain hawk-eagle’s habitat. The potential habitat areas estimated by this model substantially corresponded (89.0%) to the areas where the mountain hawk-eagle has been observed, with the overall accuracy of 91.8%. We concluded that this model could accurately estimate the potential habitat of the mountain hawk-eagle.

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With the aim of conducting efficient and accurate predictive mapping of actual vegetation, we set out to examine the data processing methods and to evaluate the accuracy of created maps. The study area contained natural vegetation and substitutional vegetation in a Fagetea-crenatae region and upper Camellietea-japonicae region distributed within a 6 km by 6 km square region on the border between Tottori and Hyogo Prefectures in Japan. A land cover map generated from satellite data and a predictive map of potential natural vegetation produced from GIS data - including elevation, landform, accumulated amount of solar radiation, and maximum snow depth data - were overlaid to create a predictive map of actual vegetation. The kappa coefficient accuracy was calculated in order to evaluate the accuracy of the predictive map of actual vegetation. Results indicated that 89% of the mapped target region had a kappa coefficient accuracy of over 0.21. Taken together, these results indicated a relatively good correspondence between the predicted results and actual onsite confirmation of distribution of vegetation in the mapped area. Within a certain degree of mapping accuracy, a predictive map of actual vegetation was successfully created.

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Energy supply by firewood through “Wakeshiba” was estimated by hearing from inhabitants and biomass survey of coppice woodland in a village of Shiso City, Hyogo Prefecture. In “Wakeshiba”, a traditional firewood-harvesting system from “Satoyama”, the common coppice woodland was shared among inhabitants every year and they could harvest firewood from the shared woodland. The rotation of the woodland was 10 to 15 years. Energy content of harvested firewood from the shared area reached to 23 - 33 GJ/year/household. This amount was more than half of 43 GJ meaning an average consumption per household in Japan. The total area of “Wakeshiba” was only a small part of whole forest area in the village, indicating that there was sufficient woody resource for energy supply to household in the village.

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Controls of floods and water quality are of great concern in Shiraoi town, Hokkaido. The function of soil and water conservation in three sub-watersheds in the town was evaluated and its reliability was tested. The methods to evaluate forest function, which was developed by Hokkaido prefecture government, are easy to employ, and the results are easy to understand for local people, and therefore we used them. The chronological changes in those functions were compared among three sub-watersheds in the following three years. They are 1948 representing the period of postwar rehabilitation, 1976 being post rapid growth period in Japanese economy, and 2006, the period after the collapse of bubble economy. Agreements of the scores and vegetation changes due to the change of social situation were examined. In results, 1) function of soil and water conservation were degraded temporarily after clear-cutting, 2) conversion of land use to the quarries caused a decline in the function of soil and water conservation, which may continue for a long time, 3) function of mitigating drought and flood was most sensitively affected by forest exploitation, 4) function of controlling water quality greatly declined when riparian zone having steep slopes was broadly developed. The scores were mostly explained by vegetation changes due to the change of social situation. While comparing scores of other sub-watersheds pointed out problems to be solved. It is necessary to simplify the evaluation procedure and show standards of judgment with regard to scores to make the guideline more lucid one.

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