The major organic components and caloric contents of high arctic bryophytes

1974 ◽  
Vol 52 (6) ◽  
pp. 1151-1161 ◽  
Author(s):  
Pekka Pakarinen ◽  
Dale H. Vitt

Thirty-five bryophyte species representing the major habitats of a high arctic tundra lowland (Devon Island, Canada, 75° N) have been analyzed for contents of nitrogen, carbon, ash, and ether- and alcohol-soluble fractions. Mean contents (%) for the green portion of these species are total nitrogen, 1.00 (1.08 ash-free); total carbon, 45.9 (48.7 ash-free); ether-soluble fraction, 2.8 (3.0 ash-free); alcohol-soluble fraction, 11.8 (12.5 ash-free); and ash, 5.7. In the hydric species group, the total nitrogen content and the alcohol-soluble fraction are significantly greater than in mesic or xeric groups. When the green and brown segments are compared, the nitrogen content and the alcohol-soluble fraction are greater in the green portion, while the ash content is higher in the brown portion. The ash-free caloric values of hydric species range from 4.57 to 4.97 kcal/g, while the mesic and xeric species have a range from 4.50 to 4.69 kcal/g. The relations between habitats and between the green and brown portions are discussed in relation to general metabolic activity and productivity.

2017 ◽  
Vol 82 (11) ◽  
pp. 1237-1246 ◽  
Author(s):  
Janko Cervenski ◽  
Dario Danojevic ◽  
Aleksandra Savic

Breeding and selection of winter pea for seed quality is a serious challenge to every breeder. The result of breeding mainly depends on good knowledge of the genetic material. Chemical and technological analysis is necessary for an accurate determination of the following traits of technologically mature seed of the winter pea collection: protein content, total nitrogen content, total sugars content, starch content, fatty oil content, cellulose content, and ash content (g (100 g)-1). The protein content in the tested lines of pea was in the range 22.86?28.04 g (100 g)-1, the total nitrogen content 3.66?4.49 g (100 g)-1, total sugars content 10.30?14.67 g (100 g)-1, starch content 39.44?46.23 g (100 g)-1, fatty oil content 1.48?1.89 g (100 g)-1, cellulose content 8.79?10.28 g (100 g)-1 and ash content 3.08?3.67 g (100 g)-1. PCA analysis was used to identify the three components that collectively explained 81.59 % of the total variation. The first component was mainly defined by the ash and the total nitrogen, protein and cellulose contents. The second one, independent from the first one, was mainly correlated to the fatty oil and starch contents, while the third was defined by the content of total sugars.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


1990 ◽  
Vol 68 (9) ◽  
pp. 1848-1856 ◽  
Author(s):  
C. Bledsoe ◽  
P. Klein ◽  
L. C. Bliss

Although mycorrhizal associations are commonly found on roots of most plant species, little is known about the presence or absence of mycorrhizae in arctic regions. In the Canadian High Arctic, roots of 55 herbaceous and woody plant species were examined for mycorrhizae during the summers of 1987 and 1988 on Devon Island, N.W.T. Ectomycorrhizal associations were found on roots of Salix arctica, Dryas integrifolia, and Potentilla hyparctica; ericoid mycorrhizae formed on Cassiope tetragona and Vaccinium uliginosum. Ectomycorrhizal roots were often covered with black hyphae resembling the fungus Cenococcum geophilum; sclerotia characteristic of this fungus were found in soil extracts. Plants expected to have endomycorrhizal associations were apparently nonmycorrhizal in the traditional sense, since no arbuscules, vesicles, or pelotons were found on any roots during two field seasons. Although extensive fungal hyphae were often present on and within roots, these hyphae could not be conclusively identified as endomycorrhizal. Some dark, septate hyphae were present; their function, although unknown, may be beneficial to the host. In a series of greenhouse bioassays using arctic soils, no endomycorrhizal associations developed on test plants. Spores of vesicular–arbuscular fungi were not found in soil extracts. Thus in this survey, only ectomycorrhizal associations were observed, suggesting that the cold, dry winter and cold, wet summer climates in this area of the High Arctic severely limit formation of endomycorrhizae. Key words: roots, fungi, ectomycorrhizae, endomycorrhizae, arctic.


2020 ◽  
Vol 63 (5) ◽  
pp. 407-417
Author(s):  
Lim Wai Yin ◽  
Lim Phaik Eem ◽  
Affendi Yang Amri ◽  
Song Sze Looi ◽  
Acga Cheng

AbstractWith the potential adverse effects of climate change, it is essential to enhance the understanding of marine ecosystem dynamics, which can be driven by the co-evolutionary interaction between autotrophs and herbivores. This study looked into the autotroph-herbivore interactions in Malaysian waters, mainly to determine if autotroph nutritional quality significantly influences herbivore consumption rates. We documented the relative consumption rate of a generalist herbivore (Chanos chanos Forsskål) obtained from the Straits of Malacca through multiple feeding trials using 12 macroalgal species collected from different coastal areas of the Straits of Malacca, the Straits of Johor, and the South China Sea. The herbivore fed selectively on the tested macroalgal species, with the most and least consumed species having the lowest and highest total nitrogen content, respectively. Besides total nitrogen content, the least consumed species also had the highest total phenolic content. Interestingly, we observed that the herbivore generally preferred to consume filamentous macroalgae, especially those collected from the South China Sea. Overall, our findings demonstrated that the feeding behaviour of a generalist herbivore could be influenced by the nutritional quality of the autotrophs, which may depend directly or indirectly on other factors such as autotroph morphology and geography.


2016 ◽  
Vol 62 (6) ◽  
pp. 485-491 ◽  
Author(s):  
Samiran Banerjee ◽  
Nabla Kennedy ◽  
Alan E. Richardson ◽  
Keith N. Egger ◽  
Steven D. Siciliano

Archaea are ubiquitous and highly abundant in Arctic soils. Because of their oligotrophic nature, archaea play an important role in biogeochemical processes in nutrient-limited Arctic soils. With the existing knowledge of high archaeal abundance and functional potential in Arctic soils, this study employed terminal restriction fragment length polymorphism (t-RFLP) profiling and geostatistical analysis to explore spatial dependency and edaphic determinants of the overall archaeal (ARC) and ammonia-oxidizing archaeal (AOA) communities in a high Arctic polar oasis soil. ARC communities were spatially dependent at the 2–5 m scale (P < 0.05), whereas AOA communities were dependent at the ∼1 m scale (P < 0.0001). Soil moisture, pH, and total carbon content were key edaphic factors driving both the ARC and AOA community structure. However, AOA evenness had simultaneous correlations with dissolved organic nitrogen and mineral nitrogen, indicating a possible niche differentiation for AOA in which dry mineral and wet organic soil microsites support different AOA genotypes. Richness, evenness, and diversity indices of both ARC and AOA communities showed high spatial dependency along the landscape and resembled scaling of edaphic factors. The spatial link between archaeal community structure and soil resources found in this study has implications for predictive understanding of archaea-driven processes in polar oases.


Soil Research ◽  
1981 ◽  
Vol 19 (3) ◽  
pp. 361 ◽  
Author(s):  
D Subhashini ◽  
BD Kaushik

Algal growth resulted in significant reductions in pH, electrical conductivity, exchangeable sodium and in hydraulic conductivity and aggregation status of the soil. There was a significant increase in the total nitrogen content of the soil due to algal growth. Two out of the three inoculated species of algae could establish in the pots along with the indigenous algal flora. Combination of gypsum and algal application were found to have appreciable reclamative properties, and the possibility of using algae as a biological input for the reclamation of sodic soils has been indicated.


1976 ◽  
Vol 54 (5-6) ◽  
pp. 533-538 ◽  
Author(s):  
Tom Booth ◽  
Paul Barrett

Phylctochytrium arcticum Barr and Rhizophlyctis harderi Uebelmesser are reported as additional taxa in soils of Truelove Lowland (Devon Island, N.W.T.) and Nowakowskiella spp., Olpidium pendulum Zopf, Pythium irregularae Buisman. Pythium spp., Phlyctochytrium arcticum, and Rhizophydium sphaerotheca Zopf are readily detectable as active organisms in Lowland microhabitats. Species diversity is greatest in mesic and warm soils and species composition of water-logged soils is different than dry soils. Soil acidity effects on distribution are discussed and autecological considerations of Nowakowskiella elegans and R. sphaerotheca with respect to pH, percentage N, C, and P, milliequivalents Ca2+ and Mg2+, moisture, and temperature are presented.


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