Colonization of decomposing deciduous leaf litter by Testacea (Protozoa,Rhizopoda): Species succession,abundance, and biomass

Summary The colonization of leaf litter by testate amoebae in a cool temperate deciduous forest was studied over the first 60 months of decomposition. No colonization of fresh leaf litter by Testacea was recorded before the first spring thaw period. Colonization of aspen and balsam leaves was similar in terms of species and numbers of species, with the balsam litter being colonized by slightly fewer species. In the aspen litter bags, all the L-layer species were present after 18 months, and all the species recorded in all soil layers were found after 60 months. The proportion of species which constructed their tests from platelets rather than sediment was 70% of the total number of species for the first 36 months of colonization of both litter types. After 60 months, seven species comprised 70% of the total numbers of Testacea but only 33–38% of the total biomass. Significant, positive correlation existed between the dry weight loss of leaf litter and the total number of active Testacea, the total number of living Testacea, and the total number of species present. The prime limitations to testacean colonization of decomposing leaf litter appeared to be substrate quality, food supply and/or availability of test-building materials.     

中国淡水与土壤有壳肉足虫最新分类名录及其区系分析

在回顾中国淡水与土壤有壳肉足虫研究历史的基础上,根据最新分类系统修订了已报道淡水与土壤有壳肉足虫的分类,共计3纲3目20科3属244种(包括52亚种).其中淡水种类37属233种及亚种,土壤种类1属64种及亚种,淡水与土壤共有17属53种及亚种.首次对中国淡水有壳肉足虫进行区系分析,用Jaccard共同系数分析西藏、贵州梵净山、湖南索溪峪、湖北东湖、江苏南京等5个地区的淡水有壳肉足虫区系相似性,区系相似性系数在0-0.25或0.25-0.5范围内,表明各地区间的区系为极不相似或中等不相似.采用模糊等价矩阵聚类法分析5个地区间的区系远近关系,结果表明其他4个地区与西藏的相似程度和地区间距离呈反比:西藏-贵州梵净山(0.35)>西藏-湖南索溪峪(0.324)>西藏-湖北东湖(0.22)>西藏-江苏南京(0.094).       

On the Notion of Microrange of Soil Testaceans

We studied species composition and population structure of testaceans (Protozoa: Testacea) in a series of soil microblock samples (weighing between 5 and 0.05 g) from podzol horizons L, F, A1A2, and A2 of cowberry-heath-lichen and gramineous-cowberry pine forests. Similarity between the testacean communities in the soil microblock samples from horizon A1A2 was at least 0.94 (by Morisita-Horn index of similarity, quantitative data), while in the enzymatic layer of litter it decreased to 0.34. The notion of microrange of soil-forming testaceans is proposed and discussed on the basis of the obtained and published data.     

The influence of substratum age on patterns of protozoan assemblages in freshwater Aufwuchs — a case study

The sulfate reduction rate was measured for almost four years in the profundal sediments of Lake Kizaki, a mesotrophic lake in central Japan. The rate was generally highest in the surface layer and decreased with depth. Seasonally, sulfate reduction tended to be high in spring and summer, and then to decrease until the end of stratification (December) in spite of a constant in situ temperature of around 6 °C, although fluctuations were found in every year. The rate also fluctuated greatly according to year. The maximum rate of sulfate reduction was 0.33 mmol m⁻² d⁻¹ in May, 1990, and the minimum was 0.004 mmol m⁻² d⁻¹ in March, 1993. These relatively low rates, compared with those reported for freshwater sediments, seem to be due to low concentrations of sulfate in the sediments (5–23 μmol l⁻¹ in the surface layer). The rate was highly correlated with the concentration of sulfate in the sediments. The addition of sulfate stimulated sulfate reduction in all sediment samples tested, but adding lactate did not. Therefore, sulfate reduction should be limited mainly by the supply of sulfate. Measurements of sulfate reduction rates at different concentrations of added sulfate revealed a low concentration of half-saturation constant as low as 12 μmol l⁻¹.     

Algae and Testacea of the Cho Oyu (Himalayas) expedition-II; Gyanophyta,Chlorophyta, Euglenophyta,Chrysophyta and Testacea

The present paper deals with the taxonomic account of Testacea and Algae other than Bacillariophyta of high altitudes of Himalayas collected during the Cho Oyu expedition. In all 80 taxa are described, out of which 19 members belong to Cyanophyta, 43 to Chlorophyta and 3 each to the groups Euglenophyta and Chrysophyta. The rest of the 12 taxa are members of Testacea. Five taxa, two varieties and three formae are new to Science.     

Density and diversity of protozoa in some arid Australian soils

This is the first extensive study of soil protozoa of arid lands. Twenty-six samples from litters, soils, termitaria, and a cyanobacterial crust, collected from central and south Australian arid lands, were analyzed for numbers and species of gymnamoebae, ciliates, and testacea. Amoebae ranged from 1,000-5,000/g of material, and were two orders of magnitude more abundant than ciliates. Both groups increased in abundance and species richness from bare soils through spinifex to mulga to chenopod vegetations. Testacea ranged 900-5,000/g with similar species richness throughout vegetations, but reached 11,900/g with a doubling of species in a refugium in Kings Canyon. The most prevalent species of amoebae, ciliates, and testacea were taxa associated with ephemeral and disturbed habitats (r-selection). The cyanobacterial crust might be considered a micro-refugium because it contained a number of non-encysting protozoa, including Thecamoeba sp. and Nassula picta, feeding on cyanobacterial filaments. The numbers and species richness of protozoa under shrubs were greater than in bare soils, supporting the resource island hypothesis that desert plants create soil heterogeneity by localizing soil fertility under their canopies.     

Notes on some testacea (protozoa,rhizopoda) of the Yugoslavian coast of the Adria near Rab

Testacea in samples collected at the beach near Rab were investigated, and 4 species were found. Ecological and zoogeographical notes are given.     

Die Testaceen (Protozoa,Rhizopoda) einiger Hochgebirgsgewässer von Mexiko,Costa Rica und Guatemala

The present paper deals with the Testacea living in several Mexican and Central American high-mountain waters. A total of 127 species, varieties and forms including 11 new ones are detected. Faunistical, ecological, zoogeographical and taxonomical notes are given. The results of investigation are represented as diagrams and extensive illustrations are provided.     

Verkieste Amöben in Steinkohlen aus dem Ruhrgebiet — erster Nachweis vonArcella Ehrenberg im Paläozoikum

Within bituminous coals of Westphalian B age pyritized amoebae of the order Testacea (thecamoebians) were detected. They may belong to the genusArcella. The appearance of this genus, known until now only since the Pleistocene, is extended far into the Palaeozoic by this observation.     

Beitrag zur kenntnis der protozoenfauna Montanas (USA): I. Die testaceen (Rhizopoda) in der region des Flathead-Lake-Tales

In the mountainous and western sections of Montana (Flathead Lake valley, USA) Testacea of 56 samples (sediment, submerged mosses, Sphagnum and peat cores) from 15 different areas were investigated. The results are explained and the colonization of the studied 4 habitats is discussed.Containing the eutrophic species Difflugia urceolata some lakes demonstrate signs of a disturbed environment.

Herrn Prof. H. Janetschek zum 65. Geburtstag gewidmet     

Testacea des Benthos der Talsperre Vranov am Thayafluss

Zusammenfassung Im Rahmen der Erforschung der Vranover Talsperre im Jahre 1951 wurde auch das Material zur Ermittlung der Zusammensetzung der Fauna der Testaceen in der Talsperre entnommen. Die Testaceen sind in dieser Talsperre bisher nicht studiert worden. In der Talsperre sind im ganzen 37 Proben ihrer ganzen Länge nach von 30 km und dies aus verschiedenen Tiefen entnommen worden. Das Material wurde durch die übliche Methodik (siehe pánek, 1963) verarbeitet. Die quantitative Analyse ist in 13 Proben durchgeführt worden.Insgesamt wurden 1353 Individuen, die zu 47 Gattungen, 121 Arten, 34 Varieten und 15 Formen gehören, besichtigt und gemessen. Von diesen 1353 Individuen sind 1 Gattung, 20 Arten, 12 Varietäten und 7 Formen als neu für die Weltfauna der Testaceen festgestellt worden.

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Summary In 1951 an informative hydrobiological observation was made on the reservoir Vranov, organized by the secondary school, Znojmo, under the direction of Dr. F. Brychta, professor. This work included also samplings performed to estimate the composition of Testacea in this reservoir. Up to this date no Testacea had been estimated here. On the whole 37 samples were collected altogether along the length of 30 km of the reservoir and at different depths. The material was treated with the use of a common procedure (tpánek, 1963). Quantitative estimations were made in 13 samples.The total of 1,353 individuals were inspected and measured, belonging to 47 genera, 121 species, 34 varieties, and 15 forms, resp. From this 1 genus, 20 species, 12 varieties, and 7 forms, resp., are new for the world fauna of Testacea.

     

Untersuchungen über Abundanz und Biomasse der sedimentbewohnenden Testaceen (Protozoa. Rhizopoda) in einem Hochgebirgsssee (Vorderer Finstertaler See. Kühtai. Tirol)

This study aims at providing quantitative information on the distribution of sediment-inhabiting Testacea in high-mountain lakes. The seasonal and spatial changes in species distribution. abundance and biomass are described. Through discussion of the relevant findings of other authors. the importance of some of those factors responsible for the Testacean distribution in time and depth is indicated.     

Testaceans (Protozoa: Testacea) in Quaternary Permafrost Sediments of Bykovsky Peninsula, Arctic Yakutia

The results of the first protozoological study in terms of paleoecology of long-term sediments and buried soils formed in the cryolite zone of northeastern Siberia are discussed. The data on testaceans (Protozoa: Testacea) inhabiting various sites of Bykovsky Peninsula, Laptev Sea coast near estuary of Lena, within the last 53000 years (Late Pleistocene and Holocene) are presented.     

An improved method for extracting bacteria from soil for high molecular weight DNA recovery and BAC library construction

Separation of bacterial cells from soil is a key step in the construction of metagenomic BAC libraries with large DNA inserts. Our results showed that when combined with sodium pyro-phosphate and homogenization for soil dispersion, sucrose density gradient centrifugation (SDGC) was more effective at separating bacteria from soil than was low speed centrifugation (LSC). More than 70% of the cells, along with some soil colloids, were recovered with one round of centrifugation. A solution of 0.8% NaCl was used to resuspend these cell and soil pellets for purification with nycodenz density gradient centrifugation (NDGC). After purification, more than 30% of the bacterial cells in the primary soil were extracted. This procedure effectively removed soil contamination and yielded sufficient cells for high molecular weight (HMW) DNA isolation. Ribosomal intergenic spacer analysis (RISA) showed that the microbial community structure of the extracted cells was similar to that of the primary soil, suggesting that this extraction procedure did not significantly change the the soil bacteria community structure. HMW DNA was isolated from bacterial cells extracted from red soil for metagenomic BAC library construction. This library contained DNA inserts of more than 200 Mb with an average size of 75 kb.     

Die Sukzession der Testaceen-Assoziationen (Protozoa,Rhizopoda) im rezenten und subfossilen Sphagnum des Obersees bei Lunz (Niederösterreich)

The Succession of Testacea-Associations (Protozoa, Rhizopoda) in Recent and Subfossil Sphagnum from the Obersee near Lunz (Austria). The present paper deals with the Testacean micro-distribution and succession on Sphagnum plants and in a peat profile from the Sphagnum bog of the Obersee near Lunz (Austria). The vertical distribution of living Testacea on Sphagnum plants from the Sphagnum bog of the Obersee near Lunz (Austria) was studied as well as the succession of the Testacean nekrocoenoses in a peat profile (0–100 cm). In the green portion of Sphagnum species possessing Zoochlorellae (Amphitrema flavum, Heleopera sphagni, Hyalosphenia papilio) and Centropyxis aculeata are living. The remaining species are distributed in the lower (dead brown) zone. Active animals were seen to a depth of 18 cm. Some Testacea individuals were able to keep alive again to a depth of 45 cm. Certain species of the Forest Moss Type (Trinema lineare, T. enchelys, Euglypha laevis) dominated in recent Sphagnum and in the peat profile to 12 cm depth. In this time the number of specimens increased. At a depth of 18 cm several typical sediment species of the genus Difflugia (amphora, corona, acuminata, lebes) appeared and the populations of Centropyxis aculeata showed characteristics of sediment-inhabiting individuals (tests covered with mineral particles and vaulted, no spines).     

Die testaceen in der umgebung der station Büschelbach (Spessart/BRD)

Taxonomy and ecology of Testacea in samples from Sphagnum and from sediments of a pool, some springs and small waters collected near Büschelbach (Bieber/Spessart, Germany) were studied. The results are explained in the present paper.

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Biologische Station Lunz und Zoologisches Institut der Universität Salzburg

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Biologische Station Lunz und Zoologisches Institut der Universität Salzburg     

Testate amoebae (Testacea) in a <Emphasis Type="Italic">Formica lugubris</Emphasis> nest: Fauna composition and structure

The fauna of testate amoebae (Testacea) in a Formica lugubris anthill and in litter layers from the control soil area in a spruce forest, Moscow region, was represented by a total of 43 species and subspecies. Their numbers ranged from 11000 ind./g air-dry substrate in the surface layer of the anthill to 62000 ind./g in the lower litter layer A0H/A1, with variation in species diversity between the samples being insignificant (24–30 species). Representatives of the genera Centropyxis, Cyclopyxis, Plagiopyxis, Corythion, and Trinema were dominant, whereas most of other species were few in numbers. The group of testacean species in the anthill was not specific, being a derivative of the testacean complex inhabiting the surrounding soil. Differences between litter layers and between these layers and substrates from the anthill concerned mainly the composition of the testacean community, which proved to change in the course of plant material decomposition: the aerophilic complex of upper layers (dominated by Centropyxis aerophila and Trinema lineare) was substituted by an edaphophilic complex (with Plagiopyxis declivis being dominant) in the nest mound of the anthill and in the lower litter layers. Plagiopyxis penardi was a eudominant species in the nest mound. Its especially high abundance is explained by deep transformation of plant remains in the nest (from moder to mull-like substrate) as the result of ant life activities.     

Taphocenoses of temporary ponds in the steppe zone of European Russia by algo-zoological analysis of recent sediments

Subfossil algae and invertebrates in the surface sediments of 26 small ponds in Saratov and Volgograd regions have been studied. Algo-zoolgical analysis of recent (surface silt) sediments has been performed. The characteristic features of taphocenoses in temporary ponds of the region under study are revealed, which distinguish them from proportionate ponds in the forest zone. It is found that sediments in the studied temporary ponds are characterized by low concentrations and diversity of biological remains, with the dominance of diatom frustules; Testacea, Ostracoda, and Spongilla sp. spicules are the predominant zoogenic remains. It is revealed that additional subfossil material can be obtained by rinsing sediments and analyzing sieve residues.     

The ratio of fungi and bacteria in the biomass of different types of soil determined by selective inhibition

Tundra, chernozem (virgin and arable), soddy-podzolic (coniferous forest, meadow, and arable), and grey forest (larch forest) soils were used to separate the contributions of fungi and bacteria to substrate-induced respiration (SIR) with the help of antibiotics. For soils with a high content of organic matter (tundra and chernozem: 12 and 8%, respectively), the procedure of selective inhibition of SIR has been optimized. This procedure consists in application of high concentrations of streptomycin (50–120 mg/g of soil) and cycloheximide (50–80 mg/g of soil) and decreasing the weight of the analyzed soil sample. Soils under study have shown the predominant contribution of fungi (63–82%) to the total SIR. The fungal-bacterial ratio in the soils of natural ecosystems (0–5 cm, without litter) was 4.3, 2.2, 1.5, and 1.5 for tundra soil, virgin chernozem, coniferous (soddy-podzolic soil), and larch (grey forest soil) forests, respectively. The lower layers of soddy-podzolic (5–10 cm) and grey forest (48–58 cm) soils showed a decrease in the fungal and increase in the bacterial component in the total SIR.