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S.F. Chen et al. 2010. A physiotope-based model for ecoregions for the the nationwide ecosystem management of Japan
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into 2 parts: Southwest (SW) Japan and Northeast (NE) Japan by the Itoigawa-Shizuoka line,
separated during the early Neogene by the subduction of the Pacific Sea Plate and the Philippine
Sea Plate. A belt of Mesozoic metamorphic rocks, the Median Tectonic Line divides SW Japan
into the Inner Zone and Outer Zone of SW Japan (Kimura, Hayami & Yoshida 1991). Hokkaido
is separated from the main island of Honshu by an important zoogeographical boundary, the
Blakiston Line, also known as the Tsuruga Straits.
The purpose of this research is to suggest a new multi-purpose ecologically significant planning
unit in Japan based on the concept of ecoregions, adjusted to suit Japan's complicated
geomorphological characteristics, accretion tectonics and geological history, and finally to look
at the geologic-climatic-physiographic units from a landscape ecology point of view.
2. Methodology
2.1 Study site
This study focuses on the main islands of Honshu, Hokkaido, Kyushu and Shikoku. The
Ogasawara archipelago, Ryukyu archipelago and other islands were excluded.
2.2 Delineation of ecoregions
2.2.1 Delineation of ecoregions at macroscale
The four major geological regions: a) Inner Zone of SW Japan, b) Outer Zone of SW Japan, c)
NE Japan and d) Hokkaido were delineated using the Index Map of Fossa Magna (Kato 1992)
and the Median Tectonic Line (Yoshikawa et al. 1981) and the Blakiston’s line. The Climate
Regions Map of Japan by Wadachi (1974) was used to determine the boundaries of the climate
regions nested within each geological zone (Fig. 1).
2.2.1 Characterization of ecoregions with physiotope classes
The Landform Classification map (MLIT) and Geological Classification Map (MLIT), both at
1:50,000 scale and in ESRI shape format were overlaid using ArcMap 9.3 (ESRI Japan). The
resulting 49 landform-geological classes were later reclassified into 7 physiotope classes that
identify accretion tectonics, tectonic relief and unique geomorphologic characteristics (Fig. 1).
The resulting physiotope classes’ map was converted into ESRI GRID format and overlaid with
geological regions for quantification of landscape metrics.
2.2 Quantification of landscape metrics
The raster version of FRAGSTATS (McGarigal & Marks 1994), developed by the Forest
Science Department, Oregon State University was used to quantify the areas, patch sizes and
variability, diversity, proximity and nearest neighbor indices of the physiotope classes of each
geological zone. Results are in both landscape level (Table 1) and class level (Fig. 2a-2f).
3. Results
3.1 Typical characteristics by geological regions
3.1.1 Region A – Inner Zone of Southwest Japan
Volcanoes and Volcanic Landforms and Quaternary Plains are the main physiotope classes of
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.