A Comparison Chart for Visual Percentage Estimation

Folk, Robert L.

doi:10.1306/d4269413-2b26-11d7-8648000102c1865d

Cited by 21 publications

(5 citation statements)

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“…Area occupied by rocks was determined by image analysis, that is, color-based segmentation using the minimum average pixel classification error (Kittler and Illingworth 1986) according to the routine in Mathematica Digital Image Processing 1.1 (Wolfram Research, Inc., Champaign, IL). Stoniness within concerned soil depth (0-60 cm) was determined as the sum of: (1) the relative volume of stones (20-200 mm) and boulders ([200 mm), which is proportional to their relative area on the profile wall in soil pits (Folk 1951;Alexander 1982), previously established by the image analysis; (2) the volume of gravel (2-20 mm). It was measured in undisturbed soil samples (200 cm 3 ), also collected for the determination of fine earth bulk density.…”

Section: Land Use Historymentioning

confidence: 99%

High organic carbon stock in a karstic soil of the Middle-European Forest Province persists after centuries-long agroforestry management

Ahmed¹,

Pichler

Homolák

et al. 2012

Eur J Forest Res

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Little is known on soil organic carbon (SOC) stocks in karst areas worldwide, although many of them have seen long-term application of agroforestry systems with a potential for carbon sequestration. Therefore, our study aimed to assess landscape-level SOC concentration and stock in the Silica Plateau, a part of the Slovak Karst Biosphere Reserve located in the Western Carpathians (Slovakia) with a centuries-long agroforestry record. The most represented local soil units are Chromi-Rendzic Leptosols and Chromic Cambisols with clayey loam texture, C/N ratio 9-12, and pH H 2 O 6.6-6.2 in their organo-mineral surface horizons. Mull surface humus form prevails under mixed forest stands dominated by hornbeam (Carpinus betulus L.), oak (Quercus petraea L.), and beech (Fagus sylvatica L.). A total of 2,700 soil samples were collected from 150 soil pits. Both SOC concentrations and stocks were determined for the 0-60 cm mineral soil layer. Soil stoniness was accounted for by means of electrical resistivity tomography. According to the analysis of covariance, cropland SOC concentration (0.026 g g -1 ) is significantly lower compared to forestland (0.040 g g -1 ) and pastureland (0.041 g g -1 ) (P \ 0.01). During the period of 130 years after forest clearing, cropland SOC stock has been reduced at an exponential decay rate of ca 0.002 year -1 , while the SOC stock in pastureland has increased following land use change from cropland by approximately 30% during the same period of time. Irrespective of land use history, overall SOC stock is high reaching on average 207.4 Mg ha -1 , out of which 66% are stored within 0-30 cm and 34% within 30-60 cm soil layers.

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Section: Land Use Historymentioning

confidence: 99%

High organic carbon stock in a karstic soil of the Middle-European Forest Province persists after centuries-long agroforestry management

Ahmed¹,

Pichler

Homolák

et al. 2012

Eur J Forest Res

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“…A comparison chart for visual percentage estimation was used to define the mortar binder/aggregate ratios at the Laboratory of the Department of Geology, University of the Basque Country (UPV/EHU). Binder/aggregate ratios were defined using a comparison chart for visual percentage estimation [42].…”

Section: Methodsmentioning

confidence: 99%

Characterization of Historic Lime Mortars from the Arch of San Martin to Identify the Construction Phases of the City Wall of Burgos (Spain)

Ponce-Antón,

Zuluaga,

Ortega

et al. 2024

Minerals

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Historical lime mortars provide valuable information on the construction phases of buildings and allow reconstruction of the chronology of the historical structures. The City Wall of Burgos and the Mudejar Arch of San Martin were declared an Asset of Cultural Interest and have been protected since 1949. Several restorations at the end of the 20th century altered the original appearance of the wall and the current gate, making it difficult to establish stratigraphic relationships between the two structures. Given the scarcity of information on the construction phases of the wall and the uncertainty of the historical dates, a mineralogical and chemical characterization of the mortars was carried out, and the suitability of the binder for radiocarbon dating was assessed. The petrographic, mineralogical and chemical analyses of the lime mortars from the Arc of San Matin show distinctive characteristics, suggesting different construction periods and production processes, where the selection of raw materials and production methods was conducted according to the construction requirements. Moreover, the presence of contaminant phases and microparticles of charcoal in the binder fraction led to discard all the samples for mortar radiocarbon dating.

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“…Flowers were identified to genus or species (Newcomb, 1989; Scoggan, 1957), which was then used to describe floral diversity within each transect. The percent cover of each blooming forb species, and total cover of grasses, forbs (blooming and non‐blooming), and bare ground was visually estimated for each quadrat using the figures provided by Folk (1951). At each sample, cloud cover (sunny, partly cloudy, or overcast) was determined visually.…”

Section: Methodsmentioning

confidence: 99%

Floral strips adjacent to Manitoba crop fields attract beneficial insects shortly after establishment regardless of management type or landscape context

Killewald

Lawley

Gulden

et al. 2023

Agri and Forest Entomology

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Insects provide valuable ecosystem services to agriculture, but their populations are often lower in these areas. We established floral strips on the edges of eight organic and seven conventional crop fields in southern Manitoba. We then compared the capture rates of ground beetles, syrphid flies and bees in floral strips; control (unmodified) field edges; nearby semi‐natural sites; and within the strip and control fields at six distances away from field borders (5–150 m). The effects of farm management and landscape context on insect abundance, diversity and associated species traits were investigated. Capture rates of bees and beetles were significantly higher within the floral strips than the control treatment. However, capture rates of syrphids were significantly higher in the control. Beetles and bees responded positively to blooming forb cover and edge density (0.5 km), whereas syrphids responded positively to non‐rewarding agriculture and negatively to the semi‐natural areas (1 km). We found no significant difference in insect abundance or diversity between organic and conventional management types, and no differences in insect abundances within the fields were detected. No significant associations between insect traits and landscape variables were identified. These results show that floral strips are effective at attracting ground beetles and bees shortly after establishment, but these communities are functionally similar to those present in control fields. Longitudinal studies are needed to determine whether populations continue to increase over time and become more functionally diverse in fields with floral strips.

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A Comparison Chart for Visual Percentage Estimation

Cited by 21 publications

References 0 publications

High organic carbon stock in a karstic soil of the Middle-European Forest Province persists after centuries-long agroforestry management

High organic carbon stock in a karstic soil of the Middle-European Forest Province persists after centuries-long agroforestry management

Characterization of Historic Lime Mortars from the Arch of San Martin to Identify the Construction Phases of the City Wall of Burgos (Spain)

Floral strips adjacent to Manitoba crop fields attract beneficial insects shortly after establishment regardless of management type or landscape context

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