Distribution of Armadillidae and Armadillidiidae (Isopoda) were investigated in Sankeien Garden in Yokohama City. The results ascertained that four species of two families were present: two native species of Armadillidae, Spherillo obscurus and Spherillo sp., and two alien species of Armadillidiidae, Armadillidium vulgare and A. nasatum. This result indicated that Sankeien Garden was the first habitat where more than three species of Isopoda were found in the region of Yokohama City. A. vulgare, an alien species, was found in a wide range, from woods to gardens, but A. nasatum was found only in limited numbers in specific habitats such as Pennisetum alopecuroides grassland. On the other hand, the native Armadillidae species, thought to prefer evergreen broad-leaved trees as their main habitat, in Sankeien Garden was found in neighboring Pinus thunbergii trees and even under debris and among brick rubble. Interestingly no Armadillidae were found in evergreen broad-leaved trees on south-facing slopes.

A comprehensive phytosociological system of Japanese forest vegetation has not been published for 22 years since MIYAWAKI, OKUDA & FUJIWARA (1994). In this study, we organized the phytosociological system of Camellietea japonicae MIYAWAKI et OHBA 1963 in MIYAWAKI, OKUDA & FUJIWARA (1994) according to the latest nomenclature (WEBER, MORAVEC & THEURILLAT, 2000). The principle of arrangement has three points: priority of the vegetation unit name, effectiveness of the description of the vegetation unit, and the presence or absence of characteristic species in the vegetation unit. The main target of this report is the forests of Kyushu, Shikoku, and Honshu. As a result, the vegetation units belonging to Camellietea Japonicae in Japan were 1 order, 4 alliances, and 40 associations. Vegetation units judged to belong to other classes were 2 orders, 2 alliances, and 17 associations.

The snow-patch meadow on the Sea of Japan side of Honshu is characterized by the dominance of Moliniopsis japonica, Carex blepharicarpa, Fauria crista-galli, Geum pentapetalum and Phyllodoce aleutica. Despite several phytosociological studies of snow-patch meadows, the dominant community of M. japonica and/or C. blepharicarpa has often been confused with the other dominant Primula cuneifolia var. hakusanensis and/or Plantago hakusanensis. The aim of this study was to describe the species composition and distribution of a snow-patch meadow characterized by the dominance of M. japonica, C. blepharicarpa, F. crista-galli, Primula cuneifolia var. hakusanensis, and Plantago hakusanensis. First, we revealed the distribution and composition of the snow-patch meadow vegetation in Honshu. Second, to consider whether this community classification was appropriate, we studied the vegetation in the northern part of the Ushiro-tateyama mountain range. Our results suggest that heavy snow climate and drainage impedance promoted the growth of Faurio-Moliniopsietum. In contrast, Plantago hakusanensis‒Primuletum cuneifoliae hakusanensis and Anaphalido‒Phyllodocetum aleuticae occurred in the high-elevation regions that were characterized by poor soil development and late snowmelt. Anaphalido‒Phyllodocetum aleuticae stands dried up rapidly after the snow melted. Faurio‒Caricetum blepharicarpae occurred at the margin of the Plantago hakusanensis‒Primuletum cuneifoliae hakusanensis and Anaphalido‒Phyllodocetum aleutica stands. Plantago hakusanensis‒Primuletum cuneifoliae hakusanensis differed from Faurio‒Caricetum blepharicarpae and Faurio-Moliniopsietum in species composition and site condition. Therefore, we report that Plantago hakusanensis‒Primuletum cuneifoliae hakusanensis is a new association.

It has been considered that the reason for the northern limit of the distribution of evergreen broadleaf forests is that they are mainly restricted by low temperature in the winter season. In addition, the climate of the winter season along the northern Pacific Ocean side of Japan is characterized not only by strictly cold temperatures but also by a continuously dry atmosphere. Consequently, cold resistance and drought residence under severe conditions are important functions for alternation of generations. The Machilus thunbergii ( KOSTERM.) forests in Japan exist at the northern limit of evergreen broadleaf forests. Measurement of air temperature, soil temperature, and leaf water content ratio of M. thunbergii occurring in the mature forest and planted potted saplings were conducted from November 2013 to October 2014 in order to understand physiological response against a low-temperature environment. Although leaf water content ratio declined respectively in winter season or before leafing, the ratio of seedlings in the mature forest decreased up to 54.2%. On the other hand, the ratio of potted saplings after one year was intensely diminished to only 11.2% in the term of the low-temperature season. The ratio didn't decline as strongly among sapling plants after two years; the minimum ratio of potted sapling plants after two years was 33.8%. Although potted saplings that were planted in the northern limit area were sensitive to low temperature, they presumably acquired cold acclimation in the initial stage after being planted.

The Great East Japan Earthquake brought serious damage from the earthquake, tsunami, and radioactive contamination along Japan’s east coast of the Pacific Ocean. The catastrophe resulted in not only direct physical disruption but also in land abandoned over the long term caused by radioactive contamination. Since the earthquake occurred on March 11, 2011, five years and eight months have passed. To assess the change in vegetation before and after the earthquake, a vegetation survey was carried out in Minami-Souma and surrounding regions from the coast to inland for about 16 km. The abundant rice fields were occupied with perennial weed plant communities, but after the decontamination, working annual plant communities took their place over five years. The rice field has two successive series in different wet and dry habitats, and the landscape of the rice field is classified into three sigma-associations. Absolute abundant wet rice fields under the radioactive contamination belong to Scirpo‒Typhaeto orientalis‒Sigmetum. The survey used rice fields characterized by Sagittario‒Monochorieto‒Sigmetum and divided into two sub-sigma-associations, Phragumito australis‒subsigmetum in wet rice fields and Solidago altissima‒subsigmetum in dry rice fields. The forest landscape did not change at the point of physiognomy, but the characteristic plant communities of those landscapes are early successional plant communities such as pioneer shrubs and sub-trees which belong to Rosetea multiflorae and Clerodendro-Mallotion.

Abstract: An investigation of vegetation and mechanical tests were conducted to clarify dynamic characteristics of trees in heavy snow areas in Japan. The vegetation association was Hamamelido‒Fagetum crenatae. There is a plasticity of tree strength from snow through an examination of bending. Tree characteristics were divided broadly into patterns through dynamic examination. Aesculus turbinata, Tilia japonica, Magnolia obovata, and Acer rufinerve showed lower strength. A. turbinata, T. japonica, and M. obovata had lower dry specific gravity values. These species were thought to have soft and light wood materials. Ulmus laciniata and A. rufinerve showed lower dry specific gravities. It was suggested that both species could be faster-growing species as well as the three species listed above. A. turbinata showed lower water content among these five species. Tilia japonica and U. laciniata are regarded as species demanding higher water content. Acer japonicum, A. sieboldianum, A. argutum, Fagus crenata, Euonymus planipes, and E. alatus var. apterus f. ciliatodentatus showed higher dynamic strength than the five species mentioned above. A. argutum, Euonymus planipes, and E. alatus var. apterus f. ciliatodentatus indicated much higher fracture strength values in spite of having the scrub shape. Fagus crenata, Acer japonicum, and A. sieboldianum did not show strain energy per volume to branch size dependency. This suggested that species have individual ecological and morphological characters in their habitat.