Mahito Kamada

Landscape structure and the disturbance regime at three rural regions in Hiroshima Prefecture, Japan

Using the vegetation maps of island, inland and mountainous rural regions in Hiroshima Prefecture in western Japan, landscape structures in terms of the size and number of patches are compared, and the characteristics of the disturbance regimes creating each landscape are discussed. Landscape structure in the island rural region is the most heterogeneous, because factors which alter the landscape structure are the most complex. This heterogeneity is established and kept by the agricultural land uses and natural disturbances such as forest fire and pine-disease. At the mountainous rural region, the landscape mosaic is characterized by the relatively large patches composed of conifer plantations and secondary deciduous oak forests. This is the result of the forestry. The inland region landscape is the most homogeneous, because factors which alter landscape structure are now absent. The complex of the physical, biological and anthropogenic forces makes the landscape unique to each region.

Human impacts on pine-dominated vegetation in rural landscapes in Korea and western Japan

To understand the human influence on the successional process of vegetation, structures of the pine forest as a dominant vegetation were compared between in Yanghwa-ri of rural Korea and Miwa-cho of rural Japan. The secondary pine forests are well developed around the villages in both regions. In rural Korea, pine forests are still used intensively for several traditional purposes. The pine forests in Yanghwa-ri of Korea, therefore, are stayed in the early stage of the succession. The floristic composition in pine forests of Yanghwa-ri was similar to that in the secondary grasslands. The fertilizer trees such as Robinia and Alnus contributed to develop the stratification of the forest. On the other hand, in Japan, almost all pine forests in rural regions had been abandoned due to the changing of traditional use because of the economic growth and the development of alternative energy sources since 1960s. In the case of pine forests of Miwa-cho, those in the early successional stage were few in number and small in patch size. Several woody plants covered under the pine canopy. The shade-tolerant shrub invaded into pine forest floor, because the undergrowth as a traditional energy source had no longer used. Pine forests were partly succeeded by deciduous oaks in Miwa-cho corresponding to the social changes. On the contrary in Yanghwa-ri, the vegetation replacement will not present because traditional management such as collecting fuels and making graveyards will be remained as a Korean ideology in the rural landscape.

Influence of cultural factors on landscapes of mountainous farm villages in western Japan

Abstract The landscapes of two different mountainous farm villages. Higashi-Iyayama in Shikoku and Hiwa in western Honshu, Japan, have been studied to clarify both the causes for change and the changes in landscape heterogeneity in relation to traditional land uses and the ensuing changes in land use. Until the 1950s, agriculture was the most important factor in the creation of landscape heterogeneities; grass mowing produced organic fertilizer in both villages and slash-and-burn agriculture was carried out in Higashi-Iyayama. These usages have been almost abolished over the last 40 years, owing to social changes such as depopulation. Some areas of grassland and slash-and-burn agricultural fields have been transformed into conifer plantations. Other areas have been completely abandoned and changed into deciduous forests, through the process of succession. A mosaic landscape, composed of conifer plantations and deciduous forests, has become established in the abandoned agricultural areas.

Vegetation mapping with the aid of low‐altitude aerial photography

Abstract. A technique for fine-scale vegetation mapping with the aid of low-altitude aerial photography was developed. The procedure is as follows: 1. The site is divided into a lattice pattern - in case the site is too large to fit into a single photograph with satisfactory resolution. The coordinates of every lattice point are surveyed to be used as control points for geometric correction. A photograph of each block of the lattice is taken using a remote-controlled camera system lifted by a captive helium balloon. 2. The vegetation is classified on the basis of a phytosociological survey. 3. The shapes and locations of vegetation patches appearing in the photographs are entered into a computer, using a digitizer. A geometric correction is carried out through coordinate transformation referring to the coordinates of the control points and subsequently a draft vegetation map is produced. Finally, discrepancies are corrected and the map is coloured to produce the final version of the vegetation map. This technique was applied to vegetation mapping at a bar, 500 m wide and 2 km long, in the river Yoshino in Shikoku, Japan. A fine-scale vegetation map was obtained and used to analyse the influence of plants on geomorphic processes and community-specific hydrogeomorphic conditions on the bar.

Hierarchically structured approach for restoring natural forest—trial in Tokushima Prefecture, Shikoku, Japan

Restoration should be a part of an overall strategy for national, regional and local land management, rather than an independent action. A hierarchically structured approach for restoration is examined by introducing actual policy and work for reestablishment of natural forest in Tokushima Prefecture, Shikoku, Japan. The goal set by Tokushima Prefectural Government is to increase the quality of biotope for indigenous plants and animals through increasing the area of natural and semi-natural vegetation and their connectivity. A “networking map” indicating high priority areas to be conserved or to be restored has been produced, using Natural Environment GIS provided by the Ministry of Environment of Japan. Having the estimated distribution of natural forests is helpful for selecting the targets for restoration, because natural forests have already disappeared from most regions due to land development. For reforestation at the cutover site, a method for designing work was developed. In order to select species and plan planting zones, ecotope types were identified both in natural forest as a reference and at the cutover site. A system for supplying indigenous seedlings was established.

Species identification based on the faecal DNA samples of the Japanese serow (Capricornis crispus)

The Japanese serow (Capricornis crispus) is endemic to mountain regions in Japan. Due to the difficulty of directly observing Japanese serows, traces such as faeces have been utilized to study their distribution and estimate their population size. However, the recent population increase of sika deer (Cervus nippon) often leads misidentification of sika deer faecal pellets as those of Japanese serows. Therefore, we developed species identification methods to differentiate between the Japanese serow and sika deer based on mtDNA cytchrome b gene sequences, and applied the method to faecal samples collected for a survey program on the Japanese serow. In 67 field-collected faecal samples examined, we could amplify mtDNA at relatively high PCR succession rates (86.6%). Species identification based on PCR–RFLPs using the cytochrome b gene revealed that 41.4% of faecal pellets of sika deer were misidentified as being from Japanese serow. This suggests that the present population size of the Japanese serow may be overestimated. This species identification method eliminates such misidentifications and should become a powerful tool for studying Japanese serow, including their distribution, precise population size, and estimations of density.

Pine forest structure in a human-dominated landscape system in Korea

To elucidate the characteristics of spatial heterogeneity in a human-dominated landscape, vegetation and community structure of pine (Pinus densiflora andP. rigida) forests were studied at rural Teokseong-ri in Chollanam-do, in the southwestern part of Korea. Daily removal of undergrowth for firewood affects the stratification and species composition in the community. In general, stratification of the pine forest develops in proportion to its distance from the main habitat of farmers, involving the residential and cultivated land. In pine forests near the main habitat of farmers, sun-demanding herbaceous plants grow well, while in remote forests, Fagaceous plants such asQuercus serrata, Q. actissima andCastanea crenata grow well. This zonation results from the fact that removal of undergrowth is greater in the forest near the main habitat of farmers, than in the remote forest. Construction and maintenance of graveyards, however, prevents development of stratification of the forest even in remote stands.

FACTORS INFLUENCING COEXISTENCE OF TWO BRACHYURAN CRABS, HELICE TRIDENS AND PARASESARMA PLICATUM, IN AN ESTUARINE SALT MARSH, JAPAN

Abstract The spatial distributions of two grapsoid crabs, Helice tridens and Parasesarma plicatum, overlap broadly in salt marsh habitats in the Yoshino River Estuary, Japan. In order to clarify factors influencing the coexistence of the two species, resource utilization was compared between the two species in space, time, and food, and intraspecific and interspecific predation was evaluated. The two species showed similar distributional patterns along the length of estuary with respect to elevation and sediment, reed, and debris conditions. Most crabs of both species dwelled solitarily in burrows. Parasesarma plicatum was most active during daytime low tide, whereas the activity of H. tridens did not differ between daytime low tide and other periods. Although both crab species had broad omnivorous diets (e.g., feeding on plants, brachyurans, insects, and detritus), H. tridens tended to consume more animal food items than P. plicatum. Laboratory experiments revealed that adults of both species preyed on subadults of the same species and different species. Adults of P. plicatum preyed on more subadults of H. tridens than conspecific subadults, whereas adults of H. tridens preyed on subadults of conspecifics and P. plicatum in similar frequency. Differences in resource utilization in conjunction with effects of predation and cannibalism, which would tend to reduce resource limitation, likely contribute to the coexistence to these two ecologically similar brachyuran crab species.

URBIO: an introduction to the International Network in Urban Biodiversity and Design

We provide a brief description of the roots, history and activities of the International Network in Urban Biodiversity and Design (URBIO). The network for education and research has its roots in Germany and was founded during the first URBIO conference in Erfurt, Germany, in 2008 with the aim of promoting urban biodiversity and design through a continuing dialogue with the Convention on Biological Diversity. The main task of the network is to support scientific exchange between researchers, practitioners, and stakeholders in the wide field of urban biodiversity and design. The second URBIO conference was held in 2010 in Nagoya, Japan, and led to further network development.

Interpopulation Variations in Life History Traits in the Fiddler Crab Uca arcuata

Abstract We compared seasonal changes in population structures and surface activities in the fiddler crab Uca arcuata between temperate (Yoshinogawa, Japan) and subtropical localities (Shinko, Japan). At Yoshinogawa, male courtship behavior was observed from April to July and pair formation from May to July, whereas at Shinko such mating behavior patterns were observed over two periods (June to September and February to March). Thus, the subtropical population appears to have a longer breeding period than the temperate population. Waving occurred from June to August at Yoshinogawa and during all months (except October and November) at Shinko. Waving frequency was higher during courting periods at all localities, although lower at Shinko compared with Yoshinogawa. Maximum body size and the size at maturity were smaller at Shinko than at Yoshinogawa. Surface and underground couplings were observed at Yoshinogawa, whereas only surface coupling was observed at Shinko. These differences and similarities are discussed from the viewpoint of habitat conditions and population characteristics.