scholarly journals The distribution of soil phosphorus for global biogeochemical modeling

2013 ◽  
Vol 10 (4) ◽  
pp. 2525-2537 ◽  
Author(s):  
X. Yang ◽  
W. M. Post ◽  
P. E. Thornton ◽  
A. Jain
Keyword(s):  
Spatial Databases ◽  
Climate Models ◽  
Soil Depth ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Parent Material ◽  
Large Uncertainty ◽  
Soil P ◽  
Mineral Particles ◽  
Microbial Utilization

Abstract. Phosphorus (P) is a major element required for biological activity in terrestrial ecosystems. Although the total P content in most soils can be large, only a small fraction is available or in an organic form for biological utilization because it is bound either in incompletely weathered mineral particles, adsorbed on mineral surfaces, or, over the time of soil formation, made unavailable by secondary mineral formation (occluded). In order to adequately represent phosphorus availability in global biogeochemistry–climate models, a representation of the amount and form of P in soils globally is required. We develop an approach that builds on existing knowledge of soil P processes and databases of parent material and soil P measurements to provide spatially explicit estimates of different forms of naturally occurring soil P on the global scale. We assembled data on the various forms of phosphorus in soils globally, chronosequence information, and several global spatial databases to develop a map of total soil P and the distribution among mineral bound, labile, organic, occluded, and secondary P forms in soils globally. The amount of P, to 50cm soil depth, in soil labile, organic, occluded, and secondary pools is 3.6 ± 3, 8.6 ± 6, 12.2 ± 8, and 3.2 ± 2 Pg P (Petagrams of P, 1 Pg = 1 × 1015g) respectively. The amount in soil mineral particles to the same depth is estimated at 13.0 ± 8 Pg P for a global soil total of 40.6 ± 18 Pg P. The large uncertainty in our estimates reflects our limited understanding of the processes controlling soil P transformations during pedogenesis and a deficiency in the number of soil P measurements. In spite of the large uncertainty, the estimated global spatial variation and distribution of different soil P forms presented in this study will be useful for global biogeochemistry models that include P as a limiting element in biological production by providing initial estimates of the available soil P for plant uptake and microbial utilization.

scholarly journals The distribution of soil phosphorus for global biogeochemical modeling

2012 ◽  
Vol 9 (11) ◽  
pp. 16347-16380 ◽  
Author(s):  
X. Yang ◽  
W. M. Post ◽  
P. E. Thornton ◽  
A. Jain
Keyword(s):  
Spatial Databases ◽  
Climate Models ◽  
Soil Depth ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Parent Material ◽  
Large Uncertainty ◽  
Soil P ◽  
Mineral Particles ◽  
Microbial Utilization

Abstract. Phosphorus (P) is a major element required for biological activity in terrestrial ecosystems. Although the total P content in most soils can be large, only a small fraction is available or in an organic form for biological utilization because it is bound either in incompletely weathered mineral particles, adsorbed on mineral surfaces, or, over the time of soil formation, made unavailable by secondary mineral formation (occluded). In order to adequately represent phosphorus availability in global biogeochemistry-climate models, a representation of the amount and form of P in soils globally is required. We develop an approach that builds on existing knowledge of soil P processes and databases of parent material and soil P measurements to provide spatially explicit estimates of different forms of soil P on the global scale. We assembled data on the various forms of phosphorus in soils globally, chronosequence information, and several global spatial databases to develop a map of total soil P and the distribution among mineral bound, labile, organic, occluded, and secondary P forms in soils globally. The amount of P, to 50 cm soil depth, in soil labile, organic, occluded, and secondary pools is 3.5 ± 3, 8.7 ± 6, 13.2 ± 9, and 3.3 ± 2 Pg P respectively. The amount in soil mineral particles to the same depth is estimated at 12.5 ± 9 Pg P for a global soil total of 41.2 ± 20 Pg P. The large uncertainty in our estimates reflects our limited understanding of the processes controlling soil P transformations during pedogenesis and lack of measurements of soil P. In spite of the large uncertainty, the estimated global spatial variation and distribution of different soil P forms presented in this study will be useful for global biogeochemistry models that include P as a limiting element in biological production by providing initial estimates of the available soil P for plant uptake and microbial utilization.

Deducing the role of eolian dust sedimentation during soil forming periods on mineral magnetic records and its implications for paleoclimate reconstructions

2020 ◽  
Author(s):  
Diana Jordanova ◽  
Neli Jordanova
Keyword(s):  
Grain Size ◽  
Conceptual Model ◽  
Climate Models ◽  
Soil Depth ◽  
Soil Formation ◽  
Magnetic Characteristics ◽  
Magnetic Fraction ◽  
Maximum Enhancement ◽  
The Past ◽  
Terrestrial Environments

<p>Obtaining reliable global and regional records of the past climatic changes during the glacial Pleistocene is of prime importance for building up consistent climate models of the near and far future. Magnetic signature along sequences of alternating loess and (paleo)soil units from the terrestrial environments is considered as semi-continuous record of climate change in the geological past. However, soil formation in aeolian landscapes may occur under different and changing conditions of dust sedimentation. Viewing from this standpoint the depth variations of several rock magnetic characteristics along profiles of Holocene soils from low Danube area allowed us to establish a set of criteria for identification of the past regimes of aeolian sedimentation persisted during the soil forming periods. A conceptual model for the time evolution of the grain size of the pedogenic magnetic fraction  with soil depth is proposed,  which is build upon  the mechanism of soil formation – accretional or  stable land surfaces,  or a combination of the two. According to the proposed conceptual model, discrimination between accretional soils and soils developed without dust additions during soil forming period can be done. Accretional soils are characterized by parallel changes in grain size sensitive magnetic proxies. Soils, developed at stable landscape conditions show gradation of the depths at which maximum enhancement of various proxies occurs with deepest occurrence of the maximum in frequency dependent magnetic susceptibility, followed by depth of maximum anhysteretic susceptibility and the normalized anhysteretic to isothermal remanence acquired at 100mT field. It is shown that the mean coercivity of the pedogenic component of accretional soils is higher than that of soils developed without eolian input at equal temperature conditions because of the soils’ thermal gradient and different depths, at which pedogenic minerals form in the two settings.</p>

Contributions to the Knowledge of Sandy Soils from Oltenia Plain

2020 ◽  
Vol 71 (1) ◽  
pp. 192-200
Author(s):  
Anca-Luiza Stanila ◽  
Catalin Cristian Simota ◽  
Mihail Dumitru
Keyword(s):  
Chemical Properties ◽  
Soil Formation ◽  
Sandy Soils ◽  
Physical Geography ◽  
Parent Material ◽  
Negative Effects ◽  
Small Water ◽  
Wind Characteristic ◽  
The One ◽  
Physical And Chemical

Highlighting the sandy soil of Oltenia Plain calls for a better knowledge of their variability their correlation with major natural factors from each physical geography. Pedogenetic processes specific sandy soils are strongly influenced by nature parent material. This leads, on the one hand, climate aridity of the soil due to strong heating and accumulation of small water reserves, consequences emphasizing the moisture deficit in the development of the vegetation and favoring weak deflation, and on the other hand, an increase in mineralization organic matter. Relief under wind characteristic sandy land, soil formation and distribution has some particularly of flat land with the land formed on the loess. The dune ridges are less evolved soils, profile underdeveloped and poorly supplied with nutrients compared to those on the slopes of the dunes and the interdune, whose physical and chemical properties are more favorable to plant growth.Both Romanati Plain and the Blahnita (Mehedinti) Plain and Bailesti Plain, sand wind shaped covering a finer material, loamy sand and even loess (containing up to 26% clay), also rippled with negative effects in terms of overall drainage. Depending on the pedogenetic physical and geographical factors that have contributed to soil cover, in the researched were identified following classes of soils: protisols, cernisols, cambisols, luvisols, hidrisols and antrosols.Obtaining appropriate agricultural production requires some land improvement works (especially fitting for irrigation) and agropedoameliorative works. Particular attention should be paid to preventing and combating wind erosion.

The Sources of Lead Pollution in a Tropical Soil Chronosequence Based on Lead Isotope

2021 ◽  
Author(s):  
Jianwu LI ◽  
Jinlin Yang ◽  
Ganlin Zhang
Keyword(s):  
Soil Depth ◽  
Parent Material ◽  
Anthropogenic Source ◽  
Anthropogenic Contamination ◽  
Good Opportunity ◽  
Soil Chronosequence ◽  
Mass Fractions ◽  
Tropical Areas ◽  
Global Biogeochemical Cycles ◽  
Significant Addition

Abstract Soil is important contributor to global biogeochemical cycles and often receives anthropogenic Pb contamination. Hainan soil chronosequence developed on basalt had provided a good opportunity to identify and quantify the relative contributions of Pb sources in remote tropical areas. The results revealed that Pb concentrations and isotopic ratios of the soils were clearly affected by anthropogenic source. The Pb concentrations and percentage changes of Pb/Th ratios showed significantly Pb enrichment. The low 206Pb/207Pb values of upper soils indicated a significant addition of extraneous Pb, whereas deeper soils showed a dominantly basaltic source. The 208Pb/206Pb vs. 206Pb/207Pb diagram of soils clearly indicated inputs of parent material and anthropogenic Pb sources. We also calculated the mass fractions of anthropogenic-derived Pb (ƒPbanthropogenic) based on isotope mass balance. The ƒPbanthropogenic values showed a generally decreasing trend with soil depth, implying a significant addition of anthropogenic Pb in top soils. The contribution of anthropogenic Pb in Hainan soil chronosequence highlighted the significance of anthropogenic contamination to soils globally.

scholarly journals Trace Metal Distribution and Mobility in Soils after Silvicultural Thinning and Burning

2017 ◽  
Vol 9 (5) ◽  
pp. 83
Author(s):  
Ngowari Jaja ◽  
Monday Mbila ◽  
Yong Wang
Keyword(s):  
Trace Metal ◽  
Management Practices ◽  
Soil Depth ◽  
Anthropogenic Activities ◽  
Block Design ◽  
Forest Health ◽  
Soil Surface ◽  
Parent Material ◽  
Design Experiment ◽  
Randomized Block Design

Silvicultural thinning and burning are common management practices that are widely used to address ecosystem problems such as tree stocking and general forest health. However, high-severity fire has variable effects on soils, resulting in damages which are directly or indirectly reflected on the trace metal chemistry of the soil. This study was conducted to evaluate the trace metal variation at the Bankhead National Forest in Northern Alabama following the silvicultural thinning and burning. The experimental site had treatments consisting of two burning patterns and three levels of thinning as part of an overall treatment of three burning patterns and three levels of thinning applied to nine treatment plots to fit a completely randomized block design experiment. Four treatments sites were used for this study and samples were collected from soil profile pits excavated at representative plots within each treatment. The samples were analyzed for trace metals-As, Cu, Ni, Zn and Pb-using Perkin Elmer 2100 ICP-OES. Post treatment samples indicated that the trace metal concentrations generally decreased with soil depth. Copper, Ni, and Zn at the Pre-burn site gradually increased with depth to a maximum concentration at about 50 cm below the soil surface. Arsenic in the surface horizons increased by 156% in the burn-only sites, 54% in the thin-only treatment, 30% for the burn and thin treatments. Such differences were unlikely due to differences in the geochemistry of the parent material, but likely due to anthropogenic activities and possibly the forest management practices in question.

scholarly journals Soil Pollution vs. Soil Collembola as a Bioindicator: A review

2010 ◽  
Vol 2 (5) ◽  
pp. 1-11
Author(s):  
Atreyee Sahana
Keyword(s):  
Organic Matter ◽  
Soil Health ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Natural Soil ◽  
Natural Health ◽  
Arthropod Fauna ◽  
Mineral Components ◽  
Inorganic Mineral

Soil is the foundation of all life activities in terrestrial ecosystems. Soil micro arthropod groups (less than 2 mm in size) like Acari and Collembola comprise more than 90% of arthropod fauna in most soil types. They majorly help in soil formation by breaking up the organic matter and mixing it up with inorganic mineral components. Among them, various species of Collembola have been proved to be effective bioindicator tool to measure soil health either it is polluted or not by its several characteristics in temperate countries. Therefore, in today’s world where pollution in soil by various agents is a baffling issue like other environmental pollutions, these natural soil inhabitants can make a hope to measure the natural health of soil.

scholarly journals Soil Carbon Sequestrations in Forest Soils in Relation to Parent Material and Soil Depth in South-Eastern Nigeria

2020 ◽  
Vol 09 (04) ◽  
pp. 400-409
Author(s):  
Chinonso Millicent Chris-Emenyonu ◽  
Emmanuel Uzoma Onweremadu ◽  
John Didacus Njoku ◽  
Chioma Mildred Ahukaemere ◽  
Benarden Ngozi Aririguzo
Keyword(s):  
Soil Carbon ◽  
Forest Soils ◽  
Soil Depth ◽  
Parent Material ◽  
South Eastern

scholarly journals Soil Quality in the Poganis, Ramnei and Doclin Hills Measures of improvment

2019 ◽  
Vol 70 (7) ◽  
pp. 2463-2470
Author(s):  
Lucian Nita ◽  
Dorin Tarau ◽  
Simona Nita ◽  
Alina Heghes ◽  
Radu Bertici ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Scientific Work ◽  
Basic Information ◽  
High Demand ◽  
Soil Resources ◽  
Genetic Types ◽  
Improvement Measures ◽  
Formation And Evolution

The purpose of current research is part of the current scientific work and practice regarding the accumulation of knowledge on the structure and characteristics of the edaphic envelope and its quality in order to establish measures for its improvement. The researched issue covers an area of 113940 ha (of which 77039 ha, 67.61% are agricultural land), located in the Poganis, Ramnei and Doclin hills, namely Barzavei Plain. The paper provides basic information and methodological elements regarding the classification and evaluation of soil resources, thus integrating itself in the broader field of complex studies of natural resources and their valorisation thus assuring the environmental protection. This research takes place at a time when there is a high demand of education in soil-related issues from its perspective as a basis for the existence of human communities, component and support of terrestrial ecosystems. From this perspective, the physico-geographic conditions of soil formation and evolution are briefly, but succinctly presented, mentioning the way in which the particularities of the area within the space taken into consideration, of only 113940 ha as a stretch, determine a great diversity of ecological conditions. They are generated by the variability of the factors (cosmic-atmospheric and telluric-edaphic), for which the main processes of formation and evolution have achieved a different development and intensity, the result of which are different genetic types of soils (related or totally different) in constant evolution and demanding specific improvement measures.

scholarly journals Phosphorus dynamics during early soil development in extreme environment

2021 ◽  
Author(s):  
Zuzana Frkova ◽  
Chiara Pistocchi ◽  
Yuliya Vystavna ◽  
Katerina Capkova ◽  
Jiri Dolezal ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Soil Development ◽  
Parent Material ◽  
Available P ◽  
Extreme Condition ◽  
Organic P ◽  
Soil P ◽  
Early Stages ◽  
P Pools ◽  
Microbial P

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P) in soils are controlled by microbial communities, the physicochemical properties of the soil and the environmental conditions. While various microorganisms involved in carrying out biogeochemical processes have been identified, little is known about the actual contribution of microbial processes, such as organic P hydrolysis and microbial P turnover, to P cycling. We thus focused on processes driven by microbes and how they affect the size and cycling of organic and inorganic soil P pools along a soil chronosequence in the Chamser Kangri glacier forefield (Western Himalayas). The rapid retreat of the glacier allowed us to study the early stages of soil formation under cold arid climate. Biological P transformations were studied with the help of the isotopic composition of oxygen (O) in phosphate (δ18OP) coupled to sequential P fractionation performed on soil samples from four sites of different age spanning 0 to 100–150 years. The mineral P, i.e. 1M HCl-extractable P, represented still 95 % of the total P stock after approximately 100 years of soil development. Its isotopic composition was similar to the parent material also at the most developed site. Primary phosphate minerals, therefore, mostly composed this pool. The δ18OP of the available P and the P bound to Fe and Al oxides instead differed from that of the parent material, suggesting that these pools underwent biological turnover. The isotopic composition of O in of the available P was mostly controlled by the microbial P, suggesting fast exchanges occurred between these two pools possibly fostered by repeated freezing-thawing and drying-rewetting cycles. The release of P from organic P become increasingly important with soil age, constituting one third of the P flux to available P at the oldest site. Accordingly, the lighter isotopic composition of the P bound to Fe and Al oxides at the oldest site indicated that this pool contained phosphate released by organic P mineralization. Compared to previous studies on early pedogenesis under alpine or cold climate, our findings suggest a much slower decrease of the P-bearing primary minerals during the first 100 years of soil development under extreme condition. However, they provide evidence that, by driving short-term P dynamics, microbes play an important role in controlling the redistribution of primary P into inorganic and organic soil P pools.

scholarly journals Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature)

2006 ◽  
Vol 6 (1) ◽  
pp. 107-173 ◽  
Author(s):  
A. Guenther ◽  
T. Karl ◽  
P. Harley ◽  
C. Wiedinmyer ◽  
P. I. Palmer ◽  
...  
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Model Development ◽  
Terrestrial Ecosystems ◽  
Global Climate Models ◽  
Earth System ◽  
Area Index ◽  
Isoprene Emission ◽  
Global Emission ◽  
High Emission

Abstract. Reactive gases and aerosols are produced by terrestrial ecosystems, processed within plant canopies, and can then be emitted into the above-canopy atmosphere. Estimates of the above-canopy fluxes are needed for quantitative earth system studies and assessments of past, present and future air quality and climate. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) is described and used to quantify net terrestrial biosphere emission of isoprene into the atmosphere. MEGAN is designed for both global and regional emission modeling and has global coverage with ~1 km2 spatial resolution. Field and laboratory investigations of the processes controlling isoprene emission are described and data available for model development and evaluation are summarized. The factors controlling isoprene emissions include biological, physical and chemical driving variables. MEGAN driving variables are derived from models and satellite and ground observations. Broadleaf trees, mostly in the tropics, contribute about half of the estimated global annual isoprene emission due to their relatively high emission factors and because they are often exposed to conditions that are conducive for isoprene emission. The remaining flux is primarily from shrubs which are widespread and dominate at higher latitudes. MEGAN estimates global annual isoprene emissions of ~600 Tg isoprene but the results are very sensitive to the driving variables, including temperature, solar radiation, Leaf Area Index, and plant functional type. The annual global emission estimated with MEGAN ranges from about 500 to 750 Tg isoprene depending on the driving variables that are used. Differences in estimated emissions are more than a factor of 3 for specific times and locations. It is difficult to evaluate isoprene emission estimates using the concentration distributions simulated using chemistry and transport models due to the substantial uncertainties in other model components. However, comparison with isoprene emissions estimated from satellite formaldehyde observations indicates reasonable agreement. The sensitivity of isoprene emissions to earth system changes (e.g., climate and landcover) suggests potentially large changes in future emissions. Using temperature distributions simulated by global climate models for year 2100, MEGAN estimates that isoprene emissions increase by more than a factor of two. This is considerably greater than previous estimates and additional observations are needed to evaluate and improve the methods used to predict future isoprene emissions.

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