Comparison of Floristic Composition of Imperata cylindica var. koenigii Communities Growing on Consolidated and on Traditional Levee Slopes in Sanda, Hyogo Pref. Western Japan.

1999 ◽  
Vol 44 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Michiko Yamato ◽  
Tamotsu Hattori ◽  
Kayo Asami
2012 ◽  
pp. 109-134
Author(s):  
P. S. Shirokikh ◽  
A. M. Kunafin ◽  
V. B. Martynenko

The secondary birch and aspen forests of middle stages of succession of the central elevated part of the Southern Urals are studied. 4 subassociations, 1 community, and 7 variants in the alliances of Aconito-Piceion and Piceion excelsae are allocated. It is shown that the floristic composition of aspen and birch secondary forests in the age of 60—80 years is almost identical to the natural forests. However, a slight increase the coenotical role of light-requiring species of grasslands and hemiboreal forests in the secondary communities of the class Brachypodio-Betuletea was noticed as well as some reduction of role the shade-tolerant species of nemoral complex and species of boreal forests of the class Vaccinio-Piceetea. Dominant tree layer under the canopy of secondary series is marked by an active growth of natural tree species.


2015 ◽  
pp. 26-37
Author(s):  
V. B. Golub ◽  
V. V. Bondareva ◽  
A. N. Sorokin ◽  
L. F. Nikolaychuk

Plant communities with reed domination (Phragmites australis agg.) occupy the large areas in the Lower Volga Valley and especially in the river delta. We have set the task to reveal the diversity of these communities in the Lower Volga Valley. For this purpose, we applied the database that is registered in the Global Index of Vegetation-Plot Databases (GIVD) under the EU-RU–002 index (http://www.givd.info/) and includes 14871 relevés made during the period from 1924 to 2013. Communities with the dominance of reed were defined as such, if the coverage of this plant was more than 50 %. We have found 375 such relevés in the database. At first, one basal community, 3 associations and 3 subassociations with domination of Phragmites australis agg. were distinguished in the Lower Volga Valley. All processing and analysis of relevés were performed using the software package JUICE 7.0. (Tichý, 2002). The «Cocktail» method was applied to establish the sociological groups that indicate environmental conditions (Bruelheide, 2000). The expert system for selection from the database of relevés by means of these groups was created. It is allowed us to ascribe relevés to earlier distinguished associations, subassociations and basal community. 171 relevés have been identified by the expert system and they were assigned to association, subassociation or the basal community. 204 relevés were not referred to any association, subassociation or the basal community. We wanted to answer the question: are there among these 204 relevés, which could be interpreted as the new syntaxa, giving them the proper ecological characteristics? For this purpose, the cluster analysis of 204 relevés has been carried out. The optimal level of clustering was determined by calculating the index of “crispness of classification” (Botta-Dukát et al., 2005). The greatest “crispness of classification” was reached at allocation of 13 clusters. Consideration of the floristic composition of allocated groups had shown that 11 of them were the transitional plant communities among the earlier established syntaxa. Only two clusters were differed in rather original structure that we could explain by the influence of environment factors. We have identified them as new associations Rubio tataricae-Phragmitetum australis and Cynancho acuti-Phragmitetum australis. All associations with the dominance of Phragmites australis agg. distinguished in the Lower Volga Valley were included in the alliance Phragmition communis Koch 1926, order Phragmitetalia communis Koch 1926. In literary sources from the ecological point of view these syntaxa are defined as the wetland communities, which are closely linked to water bodies (Šumberová et al., 2011; Ermakov, 2012). However, in many cases this definition does not correspond to the ecology of plant communities with the dominance of reed in the lower reaches of the Volga River. Ecotops of these communities are flooded for up to 2–3 months in a year and then they dry out. In the autumn, the ground water level can drop to a depth of one meter (Golub et al., 2011). The plant satellites of the reed here are often mesophytic plants such as Rubus caesius, Calamagrostis epigeios, Phalaris arundinacea, Rubia tatarica, Althaea officinalis, and Rumex stenophyllus. Therefore, the inclusion of phytocoenosises with domination of the reed in the lower reaches of the Volga River in the alliance Phragmition communis is rather relative. A correct placement of these plant communities in the system of vegetation syntaxa of the arid areas can be made only if it is based on original data obtained from much bigger territory than the Lower Volga Valley. In future geobotanical studies, it is desirable to divide the aggregation of Phragmites australis agg. into smaller species taxa.


2019 ◽  
pp. 91-94
Author(s):  
T. M. Lysenko ◽  
V. Yu. Neshatayeva ◽  
Z. V. Dutova

The International conference “Flora and conservation in the Caucasus: history and current state of knowledge” dedicated to the 130-year anniversary of the Perkalsky Arboretum took place at 22–25 of May 2019 in Pyatigorsk (Stavropol Territory) on the base of the Pyatigorsk Museum of local lore and natural history. The participants were from 11 cities of Russia and 7 Republics of the Caucasus and represented 14 institutions. Proceedings of the conference were published by the beginning of the meeting the book of abstracts includes 49 papers on the study of vascular plants, bryophytes, lichens and fungi, plant communities, as well as the protection of rare and endangered species, unique plant communities, and ecological problems in the Caucasus. The following geobotanical topics were highlighted in 13 papers: forest communities (3 reports), meadow and steppe vegetation (2), xeric open forests (2), communities of ecotone areas (1), structure of populations of rare plant species (3), as well as the history and current status of nature protected areas (2). The great emphasis has been focused on the study of floristic composition and plant populations. Thus, the conference showed that very few studies от vegetation are currently carried out in the Caucasus, and a lot of districts are not affected by the research. The greatest attention is paid to forest vegetation while meadow, steppe, alpine heath and xerophytic communities are studied rather poorly. Besides, there are “white spots” — mire, floodplain and aquatic vegetation. In nowadays, when the anthropogenic impact on the plant cover of the Caucasus is intensively increasing, it is especially important to study natural undisturbed communities preserved in protected natural areas. Another important issue is the conservation of the unique vegetation cover of the whole Caucasus. Thus, the study of vegetation of this region opens a wide field for researchers using various methods of modern plant science.


2020 ◽  
Vol 40 (6) ◽  
pp. 825-832 ◽  
Author(s):  
Miku Yabuta ◽  
Jens T Høeg ◽  
Shigeyuki Yamato ◽  
Yoichi Yusa

Abstract Although parasitic castration is widespread among rhizocephalan barnacles, Boschmaella japonica Deichmann & Høeg, 1990 does not completely sterilise the host barnacle Chthamalus challengeri Hoek, 1883. As little information is available on the relationships with the host in “barnacle-infesting parasitic barnacles” (family Chthamalophilidae), we studied the life cycles of both B. japonica and C. challengeri and the effects of the parasite on the host reproduction. Specimens of C. challengeri were collected from an upper intertidal shore at Shirahama, Wakayama, western Japan from April 2017 to September 2018 at 1–3 mo intervals. We recorded the body size, number of eggs, egg volume, and the presence of the parasite for each host. Moreover, settlement and growth of C. challengeri were followed in two fixed quadrats. Chthamalus challengeri brooded from February to June. The prevalence of B. japonica was high (often exceeded 10%) from April to July, and was rarely observed from September to next spring. The life cycle of the parasite matched well with that of the host. The parasite reduced the host’s brooding rate and brood size, to the extent that no hosts brooded in 2018.


1986 ◽  
Vol 38 (12) ◽  
pp. 1323-1329 ◽  
Author(s):  
H. SAKAI ◽  
K. HIROOKA
Keyword(s):  

2021 ◽  
pp. 1-9
Author(s):  
Chiao Kuwana ◽  
Hiroyuki Fujita ◽  
Masataka Tagami ◽  
Takanori Matsuo ◽  
Ikuo Miura

The sex chromosomes of most anuran amphibians are characterized by homomorphy in both sexes, and evolution to heteromorphy rarely occurs at the species or geographic population level. Here, we report sex chromosome heteromorphy in geographic populations of the Japanese Tago’s brown frog complex (2n = 26), comprising Rana sakuraii and R. tagoi. The sex chromosomes of R. sakuraii from the populations in western Japan were homomorphic in both sexes, whereas chromosome 7 from the populations in eastern Japan were heteromorphic in males. Chromosome 7 of R. tagoi, which is distributed close to R. sakuraii in eastern Japan, was highly similar in morphology to the Y chromosome of R. sakuraii. Based on this and on mitochondrial gene sequence analysis, we hypothesize that in the R. sakuraii populations from eastern Japan the XY heteromorphic sex chromosome system was established by the introduction of chromosome 7 from R. tagoi via interspecies hybridization. In contrast, chromosome 13 of R. tagoi from the 2 large islands in western Japan, Shikoku and Kyushu, showed a heteromorphic pattern of constitutive heterochromatin distribution in males, while this pattern was homomorphic in females. Our study reveals that sex chromosome heteromorphy evolved independently at the geographic lineage level in this species complex.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 307
Author(s):  
Makoto Inoue ◽  
Atsushi Ugajin ◽  
Osamu Kiguchi ◽  
Yousuke Yamashita ◽  
Masashi Komine ◽  
...  

In this study, we investigated the effects of the Tibetan High near the tropopause and the North Pacific High in the troposphere on occurrences of hot or cool summers in Japan. We first classified Japan into six regions and identified hot and cool summer years in these regions from a 38-year sample (1980–2017) based on the monthly air temperature. To investigate the features of circulation fields over Asia during hot and cool summers in Japan, we calculated the composite differences (hot summer years minus cool summer years) of several variables such as geopotential height, which indicated significant high-pressure anomalies in the troposphere and lower stratosphere. These results suggest that both the North Pacific and the Tibetan Highs tend to extend to Japan during hot summer years, while cool summers seem to be associated with the weakening of these highs. We found that extension of the Tibetan High to the Japanese mainland can lead to hot summers in Northern, Eastern, and Western Japan. On the other hand, hot summers in the Southwestern Islands may be due to extension of the Tibetan High to the south. Similarly, the latitudinal direction of extension of the North Pacific High is profoundly connected with the summer climate in respective regions.


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