In order to be effective, Strategic Environmental Assessment (SEA) must be implemented as early as possible in the planning process, before a detailed project blueprint has been drawn up. The assessment should be able to cope with immediate as well as cumulative effects of the proposed project, and identify the types of environments desired and various alternative solutions for achieving these. To meet these goals, the assessment must be able to quickly and effectively evaluate environments over a wide area, concentrating not only on the individual environments but on their interrelationships as well. To accomplish this mission, SEA must rely heavily on readily available digital data and GIS analyses. In Japan, various environmental data have become available in recent years. These include national land data, and vegetation and faunal distribution data produced by the Environment Agency and prefecture and municipal governments. In this research, data from previous studies and available digital data are combined with GIS analyses to develop an SEA system for use in Japan. This system is shown to be effective in evaluating the cumulative, wide-area environmental effects of a project, taking into consideration the interrelations among various environments within the target area.
The strategy of reallocating habitats for endangered species in degraded landscapes is a key target of landscape ecology. We examined the importance of seed source and topographic variation in reallocating semi-natural forests into conifer plantations from the perspective of Quercus hondae, an endangered tree species native to the warm-temperate zone in southern Japan. Q. hondae has short-distance seed dispersal and a strong dependence on micro-topography. Based on the field survey data in old growth semi-natural forests, expected tree densities of Q. hondae on the given sites was calculated for three cases with different constraints : Case-1) a constraint of the distance from semi-natural forest patches (seed-source distance), Case-2) constraints of seed-source distance and seed-source quality which varies with micro-topography of the semi-natural forest patches, and Case-3) constraints of seed-source distance, seed-source quality and habitat quality which varies with micro-topography of the target pixel (12.5m x 12.5m). Candidate reallocation sites were selected from pixels exhibiting high expected tree densities of Q.hondae to cover 30% of whole plantation area. As a result, the Case-3 adopting all three constraints exhibited improved connectivity of semi-natural forest patches. This might resulted from original connectivity of micro-topography, and indicated a secondary effect of micro-topography on the improvement of landscape functions. The conservation efficiency of each cases were compared by analyzing the relationship between reallocation area and expected tree establishment of Q. hondae, indicating the advantage of the Case-3 and Case-2 compared with Case-1 and random reallocation. Reallocation from pixels of low site productivity of conifer plantation showed the lower efficiency in requiring 10 times area of the Case-3 to achieve the same tree establishment. These results suggested an effectiveness of strategic reallocation of semi-natural forest patches based on ecological factors for conservation planning of the target species.
The objective of this study was to quantify temporal changes in the spatial structure and pattern of forest patches in the Langat Basin, Peninsular Malaysia in three different periods (1971/1972, 1981/1982 and 1991/1992) from two perspectives; firstly the changes that might impact the environment of the Basin, and secondly its implication for the forest management system. Based on these perspectives, forest patches defined in this study were classified into two groups : Group 1 : based on types of natural forest, and Group 2 : only fou based on status under the Peninsular Malaysian Forest Management Systems. For both groups landscape metrics were used to quantify landscape structure. Factor analysis was used to select the final metrics for describing landscape structure change of forest patches throughout the study period. A total of eight metrics were finally selected for Group 1 and r metrics for Group 2. This result suggests that metrics that have to be considered to give information about landscape structure change depending on how forest patches are defined. Landscape structure analysis in Group I showed that all types of forest in the Langat Basin had experienced fragmentation and deforestation particularly between the period of 1981/1982 and 1991/1992, and it occurred intensely particularly in peat swamp forests. This indicates that peat swamp forests are the most threatened forest ecosystem in the Langat Basin. At the forest management level (Group 2), most of the primary forests had changed to secondary forests between the periods of 1971/1972 and 1981/1982. The secondary forests were intensely analyses explained that human activities in the Langat Basin, including forest management systems, affect the spatial structure of the forest patches. This information is vital to influence future land use planning and forest management systems to ensure the sustainability not only of the forest ecosystems but also of the environment of the Langat Basin.
This research identifies problems with the “symbol tree” conservation system through interviews with Sapporo City Government officials and 13 residents living near the trees. “Symbol trees” are 324 giant roadside trees that have been owned by Sapporo City and examined by tree doctors since 1995. In the Chuo ward of Sapporo, 43 of these trees were felled in the past 7 years for safety reasons. There are residents who voluntarily tend to manage “symbol trees” at their own cost. This conservation system is problematic for two reasons. 1) The administration and the residents lack communication on tree conservation, and thus lack a common understanding of that ownership. 2) There is no system for paying residents who tend to manage trees, even though Sapporo owns the trees. In managing trees under the present system, the role of local government is unclear. Conserving these trees as community landmarks requires greater discussion between administration and residents.
Both the natural and social environments affect land-use patterns. We analyzed their effects on current landscape structure in forest area in Miyazaki Prefecture, southern Japan. First, we calculated Jacob's electivity index for artificial forest and natural forest using elevation and slope in four selected regions, namely Miyazaki City, Kobayashi City, Aya Town and Shiiba Village. The electivity for artificial forest was higher in lower elevation and gentle slope classes and was lower in higher elevation and steep slope class than that for natural forest. The patterns of electivity for artificial forest and natural forest were different among selected four regions. Second, we constructed a generalized linear model to explain land-use change to artificial forest within forest area using elevation and slope as independent variables. The importance of independent variables in explaining land-use change to artificial forest varied between 4 regions. In Miyazaki City and Aya Town, the effect of slope on land-use change to artificial forest was stronger than that of elevation, while in Kobayashi City and Shiiba Village vice versa. These suggested that the influence of natural environment on land-use pattern would differ under the different social environment.