On the structures of moss colony in the Yukidori Valley, Langhovde, East Antarctica

The moss vegetation developing in the Yukidori Valley, Langhovde, East Antarctica, was investigated as based on the samples in the vertical cross-section housed as the herbarium specimens to categorize the structure of the moss colony and to determine the specific composition. The vegetation consists of pure colonies of one species, and mixed colonies composed of two or rarely three moss species. Each colony was classified by species composition and degree of unevenness. The active zone, decomposed zone which were seen in the vertical cross-section, and epiphytic condition on the surface such as cyanobacteria and imperfect lichens, and rhizoidal layers in the inside of colony were determined and measured. Furthermore, the relationship between epiphytic condition and the thickness of the pure and mixed colonies was discussed taking account of ecological significances of these structural features

A Theory of Finite Topology and Image Processing

Article信州大学工学部紀要 69: 11-24 (1991)departmental bulletin pape

Reproductive phenology of subalpine moss, Polytrichum ohioense Ren. et Card.

The reproductive phenology of Polytrichum ohioense was investigated in a sub-alpine forest at the foot of Mt. Tyausu, in the Yatsugatake Mountains, Central Honshu, Japan. Shoots were collected every 2 weeks from May to October from the study site. Developmental stages of gametangia and sporophytes formed in the current and previous year were registered. The temperature above the turf occasionally dropped below 0℃ before June, while the temperature in the turf did not drop below 0℃. Juvenile antheridia formed about one month earlier than archegonia. Mature antheridia and archegonia are observed from late May to early August and from late June to mid-July, respectively. Fertilization seems to occur from late June to mid-July. Longer persistence of mature antheridia is supposed to contribute to higher efficiency of fertilization to supply its sperm for a relatively long period. And delayed formation of archegonia in the warm season may contribute to the adaptation to the temperature decrease at the beginning of the growing season. Sporophytes were found first at the end of June, then gradually grew and reached the ECI stage by October. The sporophytes seemed to spend the period of snow cover in the ECI stage, and started to grow again in the next growing season in May. Spore dispersal was observed from mid-July to mid-August. Sporophytes took 13 months to mature including a 6 month resting period. The phenological parameters observed in the present study provide a way to adapt to the the short growing season in the sub-alpine zone in Central Honshu, Japan

Ecological studies of aquatic moss pillars in Antarctic lakes 1. Macro structure and carbon, nitrogen and Chlorophyll a contents

Structures of a typical \u27moss pillar\u27 submerged in Antarctic lakes were investigated to analyze the sizes, age distribution, and composition such as shoot density, dry weight, carbon, nitrogen and chlorophyll a using a sample collected from lake B-4 Ike in the Skarvsnes region, East Antarctica. The moss pillar was mainly composed of shoots of a moss species, Leptobryum sp. Most of the green shoots of the species were located at the top surface of the pillar, and brownish old shoots with prominent vegetative diaspores, so-called rhizoidal tubers, formed the internal body of the pillar. The internal core of the pillar was nearly empty, and seemed to be decomposed considerably. Dry weight, carbon, nitrogen and chlorophyll distributions in the pillar took heterogeneous patterns, that is, they were largely centered at apical parts. It is suggested that growth of the moss pillar occurred extensively at the apical part. The age was estimated ca. 250 years at ca. 20 cm below the apical top by the AMS method. The presence of the moss pillar in lake B-4 Ike indicates that a tremendous amount of biomass has been produced under the oligotrophic freshwater Antarctic lake environment over more than a quarter millennium

Distribution of aquatic mosses in the Soya Coast region, East Antarctica

The distribution of aquatic mosses among 73 lakes in the Soya Coast region, East Antarctica, was surveyed. Two species of mosses, Bryum pseudotriquetrum and Leptobryum sp. were found at the bottom of lakes. B. pseudotriquetrum was found in 38 lakes (52.1%), mainly in freshwater lakes throughout the study area. Leptobryum sp. was found in 26 lakes (35.6%) in a rather restricted area, and mainly in relatively saline lakes

Environmental changes in Syowa Station area of Antarctica during the last 2300 years inferred from organic components in lake sediment cores

rganic components in sediment cores from Namazu Ike(lake)(length 40cm) and O-ike(lake)(length 32cm) from Syowa Station area, Antarctica were studied to clarify their features in relation to paleoenvironmental changes, together with carbon-14 dating by Tandetron accelerator mass spectrometry. Namazu Ike sediment core was mainly composed of algal(mainly cyanobacteria) and aquatic moss debris, whereas O-ike sediment core was comprised of coarse and fine sands with the influence of algal(mainly cyanobacteria) debris. The ages of core bottoms of Namazu Ike and O-ike were estimated to be 1550 and 2330 years before present(yBP), respectively. The sedimentation rates of Namazu Ike and O-ike were calculated to be 30 and 59 years/cm, respectively. Very high total organic carbon(TOC) contents(average 24.5%) of Namazu Ike revealed that the sediment core was mainly composed of organic matter. Dramatic increase of TOC/total nitrogen ratios at a depth of 25cm in Namazu Ike strongly suggests that aquatic moss increased from 1100yBP to the core top. Changes in n-alkanes, n-alkanoic and n-alkenoic acids, and sterol compositions in the O-ike sediment core, suggest that microbial composition changed considerably, but their source organisms are not clear and further studies are required

Novel Cyclic Dipeptide Dehydrogenase and Assay Method for Activity

The cell-free extract prepared from cells of an albonoursin-producing actinomycete Streptomyces sp. KO2388 was found to catalyze the dehydrogenation of cyclo (L-Phe-L-Leu) (CFL) to albonoursin. This is the first report for the dehydrogenation at the α,β-positions of amino acid residues. The simple method for determining the dehydrogenation activity was devised by measuring the increase in UV absorption of the reaction mixture at 317nm, λmax(ε25,400) of albonoursin, where CFL had no absorption. Phenazine methosulfate was the most active cofactor for the dehydrogenation among several hydrogen acceptors.アルボノルシン生産菌、Streptomyces sp. KO2388株の無細胞抽出液が、cyclo(L-Phe-L-Leu)からアルボノルシンへの脱水素反応を触媒することを明らかにした。アミノ酸残基のα,β-位での脱水素反応を酵素レベルで明らかにしたのはこの報告が初めてである。本反応の簡便な測定法として、基質cyclo(L-Phe-L-Leu)には認められない。アルボノルシンの特異的な317nmにおける紫外吸収の増加を測定する方法を考案した。本方法を用いて数種の水素受容体を試験したところ、フェナジンメトサルフェートが最も有効であると判った

Bryosphere within an Antarctic moss pillar

第6回極域科学シンポジウム分野横断セッション：[IB2] 地球環境変動の解析と地球生命システム学の構築11月19日（木）　統計数理研究所 セミナー室1（D305