THE GENESIS OF A GRAY LUVISOL WITHIN THE BOREAL FOREST REGION. I. STATIC PEDOLOGY

1985 ◽  
Vol 65 (1) ◽  
pp. 1-8 ◽  
Author(s):  
R. W. HOWITT ◽  
S. PAWLUK
Keyword(s):  
Forest Cover ◽  
Clay Fraction ◽  
Soil Matrix ◽  
Thin Sections ◽  
Organic C ◽  
Forest Region ◽  
Region I ◽  
Undisturbed Site ◽  
Extractable Al ◽  
Gray Luvisol

An undisturbed site under forest cover near Breton, Alberta was chosen to study the characteristics of a typical Gray Luvisol. Smectite and to a lesser extent mica were dominant in the clay fraction of the Bt. This horizon contained higher levels of organic C, pyrophosphate-extractable Fe and Al and dithionite-citrate-bicarbonate-extractable Al than adjacent horizons. Lime carbonate was not found to a depth of 2.25 m. Argillans occupied more than 1% of the area of thin sections from Bt and BC horizons but were better developed and more numerous at depths of 1.5–2.25 m. Pedoturbation appears to have caused the disruption and incorporation of argillans into the soil matrix. Argillans in the upper Bt horizon were optically similar to mica and contained more K than argillans from the BC horizons. Silt grains imbedded in argillans were common throughout the solum. Key words: Genesis, Gray Luvisol, pedogenesis, static pedology, clay migration, lessivage

THE GENESIS OF A GRAY LUVISOL WITHIN THE BOREAL FOREST REGION. II. DYNAMIC PEDOLOGY

1985 ◽  
Vol 65 (1) ◽  
pp. 9-19 ◽  
Author(s):  
R. W. HOWITT ◽  
S. PAWLUK
Keyword(s):  
Soil Moisture ◽  
Forest Cover ◽  
Water Movement ◽  
Colloidal Form ◽  
Forest Region ◽  
Undisturbed Site ◽  
Region Ii ◽  
Canopy Drip ◽  
Gray Luvisol ◽  
Boreal Forest Region

An undisturbed site under forest cover near Breton, Alberta, was chosen to study the dynamics of a Gray Luvisol. Soil moisture and temperature were monitored at selected depths over a 2-yr study period. Canopy drip collectors and gravity lysimeters were used to study soil solution transport and the process of lessivage. The order of cation concentration for canopy drip, LFH and Ae lysimeter samples was K+ > Ca++ > Na+ > Mg++. The lysimeter samples from the Bt showed Na+ > Ca++ > K+ > Mg++. Lysimeter studies further indicated that micaceous clays were being illuviated into the upper Bt horizon. Water movement into the Ae horizon was found to be regulated by the LFH horizon; ice lensing in winter appeared to enhance the formation of the platy structure. The major processes in this soil are the translocation of Fe, Al and organic constituents both in solution and in colloidal form; the concentration of these elements was a function of the rate of water movement. The concentration of other cations was independent of the rate of water movement. Key words: Genesis, pedogenesis, Gray Luvisol, dynamic pedology, clay migration, lessivage, illuviation

scholarly journals Relationship between soil oxidizable carbon and physical, chemical and mineralogical properties of umbric ferralsols

2011 ◽  
Vol 35 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Flávio Adriano Marques ◽  
Márcia Regina Calegari ◽  
Pablo Vidal-Torrado ◽  
Peter Buurman
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Clay Content ◽  
Selective Extraction ◽  
Total Carbon ◽  
Soil Matrix ◽  
Soil Variables ◽  
Physical Chemical ◽  
Mineralogical Properties ◽  
Extractable Al

The occurrence of Umbric Ferralsols with thick umbric epipedons (> 100 cm thickness) in humid Tropical and Subtropical areas is a paradox since the processes of organic matter decomposition in these environments are very efficient. Nevertheless, this soil type has been reported in areas in the Southeast and South of Brazil, and at some places in the Northeast. Aspects of the genesis and paleoenvironmental significance of these Ferralsols still need a better understanding. The processes that made the umbric horizons so thick and dark and contributed to the preservation of organic carbon (OC) at considerable depths in these soils are of special interest. In this study, eight Ferralsols with a thick umbric horizon (UF) under different vegetation types were sampled (tropical rain forest, tropical seasonal forest and savanna woodland) and their macromorphological, physical, chemical and mineralogical properties studied to detect soil characteristics that could explain the preservation of high carbon amounts at considerable depths. The studied UF are clayey to very clayey, strongly acidic, dystrophic, and Al-saturated and charcoal fragments are often scattered in the soil matrix. Kaolinites are the main clay minerals in the A and B horizons, followed by abundant gibbsite and hydroxyl-interlayered vermiculite. The latter was only found in UFs derived from basalt rock in the South of the country. Total carbon (TC) ranged from 5 to 101 g kg-1 in the umbric epipedon. Dichromate-oxidizable organic carbon represented nearly 75 % of TC in the thick A horizons, while non-oxidizable C, which includes recalcitrant C (e.g., charcoal), contributed to the remaining 25 % of TC. Carbon contents were not related to most of the inorganic soil variables studied, except for oxalate-extractable Al, which individually explained 69 % (P < 0.001) of the variability of TC in the umbric epipedon. Clay content was not suited as predictor of TC or of the other studied C forms. Bulk density, exchangeable Al3+, Al saturation, ECEC and other parameters obtained by selective extraction were not suitable as predictors of TC and other C forms. Interactions between organic matter and poorly crystalline minerals, as indicated by oxalate-extractable Al, appear to be one of the possible organic matter protection mechanisms of these soils.

scholarly journals THE STATE OF THE TIMBER INDUSTRY COMPLEX OF THE RUSSIAN FEDERATION IN A SPARSELY FORESTED REGION ON THE EXAMPLE OF THE VORONEZH REGION

2021 ◽  
Vol 9 (1) ◽  
pp. 62-72
Author(s):  
Irina Marchuk
Keyword(s):  
Russian Federation ◽  
Forest Cover ◽  
Paper Industry ◽  
Far East ◽  
The State ◽  
Timber Industry ◽  
Forest Region ◽  
Logging Industry ◽  
Voronezh Region ◽  
The Russian Federation

The timber industry complex of the Russian Federation ranks fourth among all branches of the country, because in terms of forest area Russia ranks first in the world (8148895 km2), which is about 49.76% of the total area of Russia. The timber industry complex is a complex system and consists of four components (logging industry, woodworking industry, pulp and paper industry, wood chemical industry). Particular attention is paid to this industry in Eastern Siberia, Western Siberia and the Far East, because these regions have the greatest forest cover. In sparsely wooded regions, the timber industry is not a priority and little attention is paid to it, both by the state and by investors. In this article, we examined the state of the forestry complex of the Voronezh region, the forest cover of this territory is only eight percent of the entire territory of the country, all forests are protective, therefore the volume of timber is carried out thanks to sanitary felling and is about 285 thousand m3. In this region there are about 20 large and medium-sized enterprises involved in the timber industry and about 40 small private enterprises. The main problem of the timber industry complex in a low-wooded region is low-quality products, imperfection of regulatory legal acts at the regional level, and lack of investment. In this regard, measures were proposed that will contribute to the development of the timber industry complex in the low-forest region.

Analysis of the patterns of large fires in the boreal forest region of Alaska

2002 ◽  
Vol 11 (2) ◽  
pp. 131 ◽  
Author(s):  
Eric S. Kasischke ◽  
David Williams ◽  
Donald Barry
Keyword(s):  
Forest Cover ◽  
Growing Season ◽  
Fire Frequency ◽  
Lightning Strike ◽  
Data Sets ◽  
Fire Cycle ◽  
Area Burned ◽  
Forest Region ◽  
Large Fires ◽  
The 1960S

Analyses of the patterns of fire in Alaska were carried out using three different data sets, including a large-fire database dating back to 1950. Analyses of annual area burned statistics illustrate the episodic nature of fire in Alaska, with most of the area burning during a limited number of high fire years. Over the past 50 years, high fire years occurred once every 4 years. Seasonal fire statistics indicated that high fire years consist of larger fire events that occur later in the growing season. On a decadal basis, average annual area burned has varied little between the 1960s and 1990s. Using a geographic information system (GIS), the spatial distribution of fires (aggregated by ecoregions) was compared with topographic, vegetation cover, and climate features of Alaska. The use of topographic data allows for a more realistic determination of fire cycle by eliminating areas where fires do not occur due to lack of vegetation above the treeline. Geographic analyses show that growing season temperature, precipitation, lightning strike frequency, elevation, aspect, and the level of forest cover interact in a complex fashion to control fire frequency.

scholarly journals A Calculation and Compiling Models of Land Cover Quality Index 2019 uses the Geographic Information System in Pariaman City, West Sumatra Province, Indonesia

2019 ◽  
Vol 8 (3) ◽  
pp. 6406-6411
Keyword(s):  
Land Cover ◽  
Urban Areas ◽  
Quality Index ◽  
Vegetation Index ◽  
Forest Cover ◽  
Normalized Difference Vegetation Index ◽  
Director General ◽  
Environmental Damage ◽  
Vegetation Density ◽  
Forest Region

The purpose of calculation and compiling the Land Cover Quality Index (LCQI) is to evaluate the value of natural and environmental resources based on land cover conditions in an administrative region such as city, regency and province in Indonesia referring to the Regulation Director General of Pollution Control and Environmental Damage Number P.1/PPKL/PKLA.4/2018. The analytical method used in the calculation of the Normalized Difference Vegetation Index (NDVI), the Maximum likelihood classification approach, and the preparation of LCQI calculation methods based on 1) sufficiency area (forest region) and forest cover at minimal 30% on rivers and islands; 2) Ability and suitability of land minimal 25%; and 3) a link with the direction of land use in urban areas of at minimal 30%. The results showed the vegetation density index value in Pariaman city was classified as a good category with a value of 0.474903 μm, the results of a land cover classification in Pariaman City with the largest region are found in mixed gardens land of 2,736.57 ha or 37%. Whereas the smallest region is found in cypress vegetation land as a greenbelt at the coastal border 12.06 ha or 0,16%. and the results of the LCQI calculation indicate the LCQI value in 2019 (24,06) which is in the alert classification (<50). The increase in land cover outside the forest region is mainly directed at increasing green open space because Pariaman City does not have natural forest which are vulnerable to changes in land cover because of its high population density

Dry forests of the Galápagos: a comparative assessment of a World Heritage Site

2020 ◽  
Vol 26 (2) ◽  
pp. 161
Author(s):  
Thomas W. Gillespie ◽  
Gunnar Keppel ◽  
Chelsea M. Robinson ◽  
Gonzalo Rivas-Torres
Keyword(s):  
Species Richness ◽  
Woody Plants ◽  
Native Species ◽  
Forest Cover ◽  
Conservation Status ◽  
Dry Forest ◽  
World Heritage Site ◽  
Dry Forests ◽  
Forest Region ◽  
The Pacific

Despite worldwide knowledge of the importance of the Galápagos archipelago, there is little comparative plot data from the forests in the dry regions. We examined patterns of woody plant (≥2.5cm diameter at breast height (DBH)) species richness and structure using Gentry’s transect method (0.1ha) on the three largest islands in the Galápagos. We identified the conservation status of woody plants within the dry forest region, assessed forest cover and change in the region, and compared field results to other tropical dry forests in the Pacific. Of the 22 species encountered (11 native, 11 endemic), there were no non-native species and only one threatened species. Isabela, Santa Cruz and San Cristóbal have similar overall levels of species, genera, family and liana richness per site, but significantly different tree species richness, density and tree height per transect. Geospatial databases identified 51 species (native 40%, endemic 60%) of woody plants (≥2.5cm DBH) within the dry forest region of the Galápagos and 13 species (10 from the genus Scalesia) on the IUCN Red List. There is an estimated 551.97km2 of dry forest in the Galápagos and there has been little change (&lt;0.01%) in forest cover from 2000 to 2015. Dry forests of the Galápagos have similar levels of species richness to Hawaii and the Marquesas but contain lower densities, basal areas and tree heights than other dry forests in the Pacific. These dry forests appear to be the best preserved and protected tropical dry forest in the Pacific.

CHARACTERIZATION AND CLASSIFICATION OF ROOT MAT HORIZONS IN SOME COASTAL BRITISH COLUMBIA PODZOLS

1989 ◽  
Vol 69 (1) ◽  
pp. 17-23 ◽  
Author(s):  
DALE E. MARTIN ◽  
L. E. LOWE
Keyword(s):  
Organic Matter Content ◽  
Matter Content ◽  
Similar Material ◽  
Organic C ◽  
Fe Content ◽  
Organic Horizons ◽  
Coastal British Columbia ◽  
Extractable Al ◽  
Root Channel

Podzols formed in high-rainfall areas of south coastal B.C. often have layers of highly organic material at depth in the profile, and in many cases, “pipes” of similar material angling down through the profile. These materials have a greasy feel, few discernible mineral grains, occasional remnants of wood structure and a cellular nature. The horizontal layers, termed "root mats", range in thickness from 1 cm to > 30 cm, and are overlain by coarse-textured material of low organic matter content. Chemically this material is similar to surficial H horizons with respect to C:N and N:S ratios, but closely resembles Podzolic B horizons with respect to Fe content and humus fraction ratios. In contrast oxalate-extractable Al values are remarkably high, sometimes exceeding 10%. The majority of the root mats can be classified as organic (> 17% organic C), either as H or O horizons. Those containing < 17% C meet the criteria for Bhf horizons. Key words: Root mat, root channel, oxalate-extractable Al, organic horizons

scholarly journals Aeolian inputs as parent materials for Podzols and terra-rossa soils in a dolomitic landscape in the Italian Alps (Salmezza, BG, Italy)

2020 ◽  
Author(s):  
Michele D'Amico ◽  
Enrico Casati ◽  
Marco Barcella ◽  
Franco Previtali
Keyword(s):  
Clay Fraction ◽  
Parent Material ◽  
Parent Rock ◽  
Annual Rainfall ◽  
Humid Climate ◽  
Quartz Content ◽  
Terra Rossa ◽  
Thin Sections ◽  
Pedogenic Processes ◽  
Different Soils

&lt;p&gt;On an unglaciated karst landscape in the Lombard Pre-Alps (Salmezza, Bergamo, Italy), an extremely high pedodiversity occurs across a few hectares on Norian dolostone. The rock is locally enriched in well crystallized sand-grained quartz. The climate of the area is suboceanic, with &gt;1500 mm of annual rainfall, and an average temperature around 6-8&amp;#176;C. Rendzic Leptosols and Phaeozems are developed on the steepest slopes, Podzols, Cambisols and Luvisols on flatter areas, while Rhodic Luvisols/Alisols (Terra-Rossa soils) are found in doline cracks and crevices. The sand-grained quartz content of the parent rock seems to be the main soil differentiating factor: where it is abundant (ca. 10-20% in volume), it is responsible for the genesis of Podzols.&lt;/p&gt;&lt;p&gt;We sampled and analyzed 9 soil profiles from the Salmezza area, thus characterizing all pedogenic processes active in the area. In particular, we analyzed standard soil chemical properties (pH, organic carbon, base status and Cation Exchange Capacity, dithionite and oxalate-extractable Fe and Al); we performed a total elemental analysis on most samples and on substrate samples, in order to calculate mass balance and element loss and enrichment; we observed thin sections and performed XRD analysis in powder samples and on the clay fraction of most pedogenic horizons as well.&lt;/p&gt;&lt;p&gt;The parent material is a rather pure dolostone, composed of dolomite, locally enriched in quartz. No other minerals have been observed. Very little amounts of Fe, Al and other elements are thus included in the parent rock (almost completely composed of Ca, Mg and Si), often very close to the analytical detection limit. Ca and Mg were almost completely lost during most soil forming processes in this temperate humid climate, while the enrichment in Si, Fe, Al varies broadly amidst the different soils, thanks to different pedogenic processes. Fe and Al, in particular, were up to 120 times more concentrated in Bt and Bhs horizons than in the parent rock. The ratios between stable elements in rocks and soils verifies important inputs of aeolian materials. The values are, however, different also amidst different soils, so an univocal origin of aeolian materials cannot be hypothesized. The mineralogy of the clay fraction is also strongly modified by pedogenesis, so that each soil type is characterized by a different mineralogical assemblage, making it difficult to detect signatures of specific aeolian origins as well.&lt;/p&gt;

Dispersed clay and organic matter in soil: their nature and associations

Soil Research ◽  
1999 ◽  
Vol 37 (2) ◽  
pp. 289 ◽  
Author(s):  
P. N. Nelson ◽  
. A. Baldock ◽  
J. M. Oades ◽  
G. J. Churchman ◽  
P. Clarke
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
High Surface ◽  
High Surface Area ◽  
Clay Fraction ◽  
Sodic Soils ◽  
Organic C ◽  
Clay Dispersion ◽  
13C Nuclear Magnetic Resonance ◽  
Colloidal Materials

Clay dispersion in soil results in structural instability and management problems. The aim of this study was to determine whether or not the easily dispersed colloidal materials differ in their properties from colloidal materials that do not disperse easily. Soil samples from the topsoil of sodic and non-sodic variants of an Alfisol under irrigated pasture (Kyabram, Victoria, Australia), and from the topsoil and subsoil of a sodic Alfisol under cultivation (Two Wells, South Australia) were fractionated into easily dispersed, moderately dispersed, and difficult to disperse clay, and silt, sand, and light fractions. As a proportion of total clay, easily dispersed clay content was greatest in the subsoil, and least in the Kyabram topsoils. In the topsoils, easily dispersed clay had larger particle size and lower cation exchange capacity than difficult to disperse clay, suggesting that high surface area and charge lead to increased inter-particle interactions and lower dispersibility. Easily dispersed clay had lower organic C contents than difficult to disperse clay. Organic matter was examined by 13C nuclear magnetic resonance, and the spectra were interpreted using major groups of biomolecules as model components. In all soils, organic matter in the easily dispersed clay fraction contained a high proportion of amino acids, suggesting that amino acids or proteins acted as dispersants. Difficult to disperse clay contained a high proportion of aliphatic materials in the topsoils, and carbohydrate in the subsoil, suggesting that these materials acted as water-stable glues. Selectivity for Na (KG) was negatively correlated with organic C content in the clay fractions. In the Kyabram soils, KG was greater in easily dispersed clay than in difficult to disperse clay. In Two Wells soil, clay with high KG appeared to have already moved out of the topsoil, into the subsoil. This work showed that variability in the nature of organic matter and clay particles has an important influence on clay dispersion in sodic and non-sodic soils.

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