Terrestrialization and vegetation succession in cut-off channels were studied in the Nishibetsu River, Hokkaido, Japan, to clarify causal factors that governed the spatiotemporal change in vegetation over the last 100 years. According to aerial photo interpretation of 128 cut-off channels, terrestrialization and vegetation succession began on the river banks of main channels in natural river sections without artificial modification. In channelized sections with artificial levees, terrestrialization of the channels depended on the time when they cut off. Channels that cut off from the river before channelization underwent gradual terrestrialization and succession because the water table level dropped after river incision in the straightened channels. In contrast, little terrestrialization occurred in the cut-off channels that were formed by channelization where artificial levees decreased flood frequency to reduce sedimentation in the cut-off channels.
Species composition of the terrestrial vegetation changed in cut-off channels: vegetation dominated by the pioneer species Salix pet-susu changed to swamp-forest species such as Fraxinus mandshurica var. japonica, Ulmus davidiana var. japonica, and Alnus hirsuta. This change occurred on alluvial plugs 40–60 years after being cut, whereas it occurred in interior areas ca. 25 years after being cut. The vegetation succession was probably caused by changes in the frequency and duration of flooding; flooding was reduced by the raised land surface of alluvial plugs. The succession in interior areas may have been influenced by changes in groundwater level fluctuations; the water table was stabilized by the sedimentation of silt and clay.
Microlandforms with various surface elevations are one of the important factors controlling the spatial arrangement of terrestrial vegetation. Trees were arranged in the order of surface elevation as follows: Ulums davidiana var. japonica and Syringa reticulata; Fraxinus mandshurica var. japonica, Alnus hirsuta, and Sambucus racemosa subsp. kamschatica; and herbs distributed were Sasa kurilensis, Equisetum hyemale, Urtica platyphylla, Carex caespitosa, and Carex rhynchophysa.
There were differences in the terrestrialization processes between upper and lower alluvial plugs. Terrestrialization and therefore vegetation succession on the lower plugs were delayed by erosion that occurred when flooded water was discharged through the plugs. The ground surface of lower alluvial plugs consisted of coarser sediment (sand) than that of upper plugs, resulting in differences in vegetation between upper and lower plugs. In the interior areas of cut-off channels, old landforms that had formed before being cut, such as terraces, provided diverse environments for various types of vegetation. In addition to such old landforms, debris flows from valley side slopes modified the vegetation in the interior areas.

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The village of Shirakawa, located in a mountainous region in Hida area, was designated by the UNESCO World Heritage Foundation as the Historic Villages of Shirakawa and Gokayama in 1995. Today, this village is famous for its gassho-style thatched houses, and is widely recognized as a region preserving the traditional Japanese landscape. This paper analyzes how Shirakawa village achieved such recognition and examines how the image of the mountain village has changed in modern Japan. During the Meiji era, Shirakawa village viewed as an uncivilized “other world” populated by the illiterate; in particular, its extended family system was thought to be a barbaric custom. In that extended family system, none except the patriarch was allowed to marry. Some newspaper articles reported that this led to immorality. This image began to erode in the late Taisho era. In the beginning of the Showa era, the traditional customs of Shirakawa, for example, the family system, folk songs, and thatched houses with a steeply pitched roofs attracted a great deal of public attention as a cultural heritage. Factors in the changing image of this village are examined from the following two viewpoints. The first factor was the change in industries, traffic, and customs in Shirakawa. Until the latter half of the Meiji era, the main occupations of village people were agriculture and sericulture. In the Taisho era, a power plant and a forestry company newly relocated to the area, and shops, inns, and restaurants opened for business. Additionally, roads from the town of Takayama to Shirakawa were constructed in the 1930s, and therefore it became possible for visitors to travel easily to the village using this modern public transport. The second factor was a blossoming of intellectual activity in Hida area. During the prewar Showa era, folklorists and travel agents in Takayama and Gero actively advertised this area. Shirakawa was presented as a historical village with beautiful scenery and traditional customs. In Takayama, Ema Nakashi and his wife Mieko established the Hida Archaeology and Folklore Society and researched Shirakawa folkways. As a result, Shirakawa became well known among ethnographers those interested in local studies as a rare region where traditional customs were preserved. Numerous researchers, students, and journalists often visited this village under the guidance of the Emas to observe the family system, history, farmhouses, and scenery, and were aware that the traditional culture remained intact. Some intellectuals in Hida area had recognized the cultural value of gassho-style thatched dwellings before Bruno Taut introduced them internationally.

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Air and ground temperatures were monitored on and around blocky deposits such as rock glaciers and talus slopes in the alpine zone of the Yari-Hotaka Mountains, northern Japanese Alps, using miniature temperature data loggers. The results of air temperature monitoring indicated that the mean annual air temperature in the summit area of the Yari-Hotaka Mountains was about −2.5°C, and this area belong to the discontinuous permafrost area.
The results of ground surface temperature at leeward sites (Tenguppara cirque and Oh-kiretto cirque) showed that a sufficiently thick snow cover insulates the ground surface from short-term variations in atmospheric conditions during the winter. At some of these sites, the bottom temperatures of snow cover (BTS) in late winter were less than −3°C, and mean annual ground surface temperatures (MAST) were less than 0°C. These results suggest that mountain permafrost can be present in some blocky deposits. BTS values at significantly large boulder site were distinctly colder than those at other sites. This intensive cooling of the ground surface may be caused by conduction through surface boulders protruding into and through the snow cover.
At some wind-blown sites located on a rock glacier in the northern Minamisawa cirque, ground surface temperatures were influenced by atmospheric variations throughout the whole winter, and MAST was close to 1°C. Ground surface temperature evolution on the furrows of this rock glacier do not undergo short-term fluctuations during the winter, and BTS in late winter at these sites was less than −3°C. These results suggest the occurrence of patchy permafrost in this rock glacier.

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A 2,500-year vegetation history was reconstructed by analyzing phytolith assemblages in sediments from Paitan Lake located in the Central Plain of Luzon, the Philippines. Five local zones of phytolith assemblage were established for the sediment sequence analyzed. Cogon (Imperata) dominated in Zone 5 (ca. 2,460–1,410 cal. yr BP), cogon and other Gramineae grasses and coniferous trees dominated in Zone 4 (ca. 1,410–1,240 cal. yr BP), non-cogon Gramineae grasses and trees dominated in Zone 3 (ca. 1,240–1,150 cal. yr BP), cogon and other Gramineae grasses and trees dominated in Zone 2 (ca. 1,150–350 cal. yr BP), and Oryza sativa (rice) increased while trees disappeared in Zone 1 (ca. 350–0 cal. yr BP). The results of this study indicate that trees were included in the component species of the vegetation at least until ca. 350 years ago, and that woodlands were replaced with rice fields and Gramineae grasslands. The development of cogon grasslands in Zone 5 may have been due to drier climatic conditions.

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Betula davurica (Asian black birch) is distributed in the central Honshu and Hokkaido regions of Japan. In these regions, the distribution of B. davurica is controlled by microtopography and surface soil. However, the factors affecting the distribution of B. davurica forests have not been studied in detail.
In this paper, we discuss the distribution characteristics of B. davurica forests and surrounding forests using data compiled from field surveys. We also examined the factors affecting the distribution of B. davurica forests on a landslide area on Mt. Takashino in the Soto-Chichibu Mountains.
Many B. davurica trees grow on the stony soil of gentle slopes in the landslide area. This stony soil originated from landslides of earth and sand during a period of dozens of years. In this area, the main local species, Quercus crispula and Quercus serrata, have low dominance. The main factors affecting the distribution of B. davurica forests are the characteristics of the landslide area. It is easy for seeds and seedlings to invade and grow on the gentle slopes, and the landslide forms a large canopy gap periodically. B. davurica can invade this canopy gap much faster than other species, as it has a rapid growth rate. Therefore, we concluded that B. davurica can form forests on landslide landforms.

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