An approach to quantitative classification of nutrient regimes of forest soils

1988 ◽  
Vol 66 (12) ◽  
pp. 2640-2653 ◽  
Author(s):  
P. J. Courtin ◽  
K. Klinka ◽  
M. C. Feller ◽  
J. P. Demaerschalk
Keyword(s):  
Numerical Analysis ◽  
Forest Soils ◽  
Soil Nutrient ◽  
Floristic Composition ◽  
Site Index ◽  
Quantitative Classification ◽  
Rooting Zone ◽  
Calcium Magnesium ◽  
Soil Groups

Many workers have classified nutrient regimes of forest soils, but there have been few attempts to provide an objective means of defining soil nutrient regimes. This objective was accomplished in the present study by numerical analysis conducted on 195 soil samples of vegetation and soils from coastal British Columbia. The differentiating characteristics used in the classification were pH (H2O) and the C/N ratio of the humus forms; and total soil nitrogen (kg/ha) and sum of exchangeable calcium, magnesium, and potassium (kg/ha) within the soil rooting zone. Numerical analysis distinguished seven soil groups. These groups were related to the floristic composition of understory vegetation and to forest productivity as indicated by site index. These vegetation – soil relationships were then used to assign the soil groups into five soil nutrient regime classes: very poor, poor, medium, rich, and very rich.

Quantitative characterization of nutrient regimes in some boreal forest soils

1994 ◽  
Vol 74 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Karel Klinka ◽  
Gordon J. Kayahara ◽  
Qingli Wang
Keyword(s):  
Forest Floor ◽  
C:N Ratio ◽  
Mineral Soil ◽  
Soil Nutrient ◽  
Site Index ◽  
Total Carbon ◽  
Single Measure ◽  
Quantitative Classification ◽  
Mineralizable N ◽  
Boreal Soils

In order to assess to what extent soil nutrient properties support differentiation of field-identified soil nutrient regimes, composite samples from each forest floor and 0–30 cm of the mineral soil were collected from 116 forest stands in central British Columbia. The samples were analyzed for acidity, total carbon (tC), total nitrogen (tN), mineralizable-N (min-N), and extractable Ca, Mg, K, P, and SO4-S (eCa, eMg, eK, eP, eSO4); and the results were expressed as concentrations on a dry-mass basis. Mineralizable-N of the mineral soil showed (1) the largest amount of variation in the population of sampled soils, (2) significant differences (P < 0.01) among field-identified soil nutrient regimes, and (3) strong correlations with tC, tN, and eCa, eMg, and eK. Using mineral soil min-N as a differentiating characteristic, the following limiting values (mg kg−1) were proposed to provide an objective means of defining soil nutrient regimes: < 2 for very poor, 2–8.9 for poor, 9–27.4 for medium, 27.5–110 for rich, and > 110 for very rich. Site index (height at 50 yr breast height age) of lodge-pole pine (Pinus contorta Dougl. ex Loud) and interior spruce [Picea engelmannii Parry ex Engelmann × P. glauca (Moench) Voss] increased from very poor to very rich soils; however, the differences among site indices of contiguous soil nutrient regimes were largely insignificant. Regression analysis indicated that (1) soil moisture accounts for the largest proportion of the variation in site index, (2) models using C:N ratio of the forest floor and 0–30 cm of the mineral soil had a stronger relationship with site index (0.38 ≤ R2 ≤ 0.43, standard error < 3.0 m) than those using min-N. These results gave further evidence that min-N in the 0–30 mineral soil is a good single measure representing soil nutrient conditions, and justify the use of the existing field procedure for estimating soil nutrient regimes in montane boreal soils. Key words: Boreal soils, soil nutrient regime, quantitative classification, mineralizable-N, site index

scholarly journals Machine learning algorithm improved automated droplet classification of ddPCR for detection of BRAF V600E in paraffin-embedded samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel A. Colozza-Gama ◽  
Fabiano Callegari ◽  
Nikola Bešič ◽  
Ana C. de J. Paviza ◽  
Janete M. Cerutti
Keyword(s):  
Machine Learning ◽  
Sanger Sequencing ◽  
Learning Algorithm ◽  
Absolute Quantification ◽  
Braf V600e Mutation ◽  
Braf V600e ◽  
Driver Genes ◽  
Quantitative Classification ◽  
Cancer Driver

AbstractSomatic mutations in cancer driver genes can help diagnosis, prognosis and treatment decisions. Formalin-fixed paraffin-embedded (FFPE) specimen is the main source of DNA for somatic mutation detection. To overcome constraints of DNA isolated from FFPE, we compared pyrosequencing and ddPCR analysis for absolute quantification of BRAF V600E mutation in the DNA extracted from FFPE specimens and compared the results to the qualitative detection information obtained by Sanger Sequencing. Sanger sequencing was able to detect BRAF V600E mutation only when it was present in more than 15% total alleles. Although the sensitivity of ddPCR is higher than that observed for Sanger, it was less consistent than pyrosequencing, likely due to droplet classification bias of FFPE-derived DNA. To address the droplet allocation bias in ddPCR analysis, we have compared different algorithms for automated droplet classification and next correlated these findings with those obtained from pyrosequencing. By examining the addition of non-classifiable droplets (rain) in ddPCR, it was possible to obtain better qualitative classification of droplets and better quantitative classification compared to no rain droplets, when considering pyrosequencing results. Notable, only the Machine learning k-NN algorithm was able to automatically classify the samples, surpassing manual classification based on no-template controls, which shows promise in clinical practice.

scholarly journals Author Correction: Conventional analysis methods underestimate the plant-available pools of calcium, magnesium and potassium in forest soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jérémie Bel ◽  
Arnaud Legout ◽  
Laurent Saint-André ◽  
Steven J. Hall ◽  
Stefan Löfgren ◽  
...  
Keyword(s):  
Forest Soils ◽  
Conventional Analysis ◽  
Analysis Methods ◽  
Calcium Magnesium

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Quantitative classification of near-fault ground motions selected by energy indicators

Structures ◽  
2022 ◽  
Vol 35 ◽  
pp. 780-791
Author(s):  
Dahai Zhao ◽  
Huiwei Wang ◽  
Ding Wang ◽  
Ruiguang Zhu ◽  
Jinghui Zhang
Keyword(s):  
Ground Motions ◽  
Quantitative Classification ◽  
Near Fault ◽  
Energy Indicators

scholarly journals Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture

2009 ◽  
Vol 44 (8) ◽  
pp. 996-1001 ◽  
Author(s):  
Pedro Rodolfo Siqueira Vendrame ◽  
Robélio Leandro Marchão ◽  
Osmar Rodrigues Brito ◽  
Maria de Fátima Guimarães ◽  
Thierry Becquer
Keyword(s):  
Total Carbon ◽  
Soil Macrofauna ◽  
Exchangeable Calcium ◽  
Exchangeable Ca ◽  
Calcium Magnesium ◽  
Distrito Federal ◽  
Calcium And Magnesium ◽  
Taxonomic Groups ◽  
The Relationship ◽  
Soil Groups

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.

scholarly journals A STUDY ON THE QUALITY OF VARIOUS TYPES OF CHEESE PRODUCED AND CONSUMED IN GREECE

1974 ◽  
Vol 25 (1) ◽  
pp. 25
Author(s):  
Κ. ΣΚΟΥΝΤΖΟΣ ◽  
Ι. ΑΣΙΚΗΣ
Keyword(s):  
Sodium Chloride ◽  
Protein Content ◽  
Fat Content ◽  
Market Area ◽  
Laboratory Examination ◽  
Quantitative Classification ◽  
Quantitative Characteristics

Laboratory examination of 828 samples of four typss of Greek cheese («telemes» : 415, «kasseri» : 164, «kefalotyrion» : 170, «gruyère» : 79) obtained from the Attikan market area, revealed, that : a. There is great variation relative to the water as well as the fat contents of the various types of cheese, resulting in the lack of standardized organoleptic and quantitative characteristics in the types of cheeses sold. b. The «kefalotyrion» cheese in particular contains significantly high quantities of sodium chloride. The authors suggest that ins criterion of fat content established so far for the quantitative classification of Greek cheese types be replaced by the criterion of protein content.

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