Application of Topographic Analyses for Mapping Spatial Patterns of Soil Properties

Landscape topography is a key parameter impacting soil properties on the earth surface. Strong topographic controls on soil morphological, chemical, and physical properties have been reported. This chapter addressed applications of topographical information for mapping spatial patterns of soil properties in recent years. Objectives of this chapter are to provide an overview of (1) impacts of topographic heterogeneity on the spatial variability in soil properties and (2) commonly used topography-based models in soil science. A case study was provided to demonstrate the feasibility of applying topography-based models developed in field sites to predict soil property over a watershed scale. A large-scale soil property map can be obtained based on topographic information derived from high-resolution remotely sensed data, which would benefit studies in areas with limited data accesses or needed to extrapolate findings from representative sites to larger regions

Spatial Estimations of Soil Properties for Physically-based Soil Erosion Modelling in the Three Gorges Reservoir Area, Central China

Soils present a central medium for processes between the environmental spheres, and therefore play a key role in the functioning of terrestrial ecosystems. However, soil erosion as a natural force of landscape evolution adversely affects the capacity of soils to support ecosystem services. Moreover, inadequate agricultural practices, deforestation, and construction activities amplify natural soil loss rates and transform soil erosion to a major threat for managed ecosystems worldwide. Particularly, the Three Gorges Reservoir Area in China is highly susceptible to soil erosion by water. This is attributable to unfavorable environmental conditions, such as rainfall events of high intensity and steep slope inclinations in areas of extensive, but small-scale crop cultivation. Moreover, in the course of the impoundment of the Yangtze River in the area of the Three Gorges, resettlements and accompanied deforestation reinforced the risk of hazardous soil erosion, which attenuates soil productivity and threatens the functioning of the reservoir. Therefore, conservation measures to stabilize steep sloping surfaces have been implemented to mitigate the hazardous effects of soil erosion. However, to assess the conservation measures an efficient tool is required to identify spatial soil erosion patterns in small, mountainous, and data scarce catchments within the Three Gorges Reservoir Area. The present thesis aims to provide an efficient modelling framework that facilitates a detailed quantification of sediment reallocations due to erosive rainfall-runoff events. Therefore, Digital Soil Mapping techniques based on Latin Hypercube Sampling and Random Forest regression were applied to derive spatially distributed data on soil properties and to furnish a physically- and event-based soil erosion model. The soil sampling design was optimized to address the difficult terrain, an integrative use of legacy soil samples, and a reduced sample set size. Furthermore, the present thesis introduces a spatial uncertainty measure, which was used to identify areas for additional sampling to further refine initially processed soil property maps. In addition, continuous data on rainfall, runoff, and sediment yields were obtained to identify erosive rainfall-runoff events and to calibrate the physically-based soil erosion model EROSION 3D. Evaluation of the hypercube sampling design was conducted by comparing it to a simulated Latin Hypercube design without constraints in terms of operability and efficiency adjustments. Using the optimized sample set size of n = 30, the proposed sample design adequately reproduced the variation of terrain parameters, which served as proxies on the target soil properties of coarse, medium, and fine topsoil sand contents. Furthermore, the validity of the approach was assessed by estimating the spatial distribution of the target soil properties and validating the results independently. The results show convincing accuracies with R²-values between 0.59 and 0.71. The adequacy of the uncertainty-guided sampling for refining initial mapping approaches was evaluated by comparing the refined maps of topsoil silt and clay contents to the initial and further mapping approaches that exclusively used random samples from the entire study area. For the comparative analysis, the quality of the approaches was assessed by independent, bootstrap-, and cross-validation. The refined mapping approach performs best, showing a reduced spatial uncertainty of 31% for topsoil silt and 27% for topsoil clay compared to the initial approaches. Using independent validation, the accuracy increases by similar proportions, showing an accuracy of R² = 0.59 for silt and R² = 0.56 for clay. The EROSION 3D model runs were evaluated using the measured sediment yields. The model performs well for large events (sediment yield > 1 Mg) with an average individual model error of 7.5%, while small events show an average error of 36.2%. The focus of analysis was led on the large events to evaluate reallocation patterns. Soil losses occur on approximately 11.1% of the study area with an average soil loss rate of 49.9 Mg ha-1. Soil loss mainly occurs on crop rotation areas with a spatial proportion of 69.2% for ‘corn-rapeseed’ and 69.1% for ‘potato-cabbage’. Deposition occurs on 11% of the study area. Forested areas (9.7%), infrastructure (41%), cropland (corn-rapeseed: 13.6%, potato-cabbage: 11.3%), and grassland (18.4%) are affected by deposition. Since the vast majority of annual sediment yields (80.3%) were associated to a few large erosive events, the modelling framework can be recommended to identify sediment reallocations and to assess conservation measures in small catchments in the Three Gorges Reservoir Area

サンチゲンリュウイキニオケルカンイブンプガタドジョウシンショクモデルカイハツニムケタドジョウオヨビチヒョウヒフクノトクセイヒョウカ

博士（農学）東京農工大

Soil Microbial Diversity Across Different Agroecological Zones in New South Wales

A synergistic relationship between soil diversity (pedodiversity) and soil microbial diversity (biodiversity) seems axiomatic. Soil microbes contribute with biogeochemical cycles on which rely soil services (e.g. food production) and; vice-versa the soil matrix provides the living conditions that structure its microbial communities. A better insight would enable us to quantify/qualify and so sustain, protect, and improve those processes underpinned by soil microorganisms. We hypothesize that the structural patterns of soil microbes rely on multivariate soil units and gradients (e.g. soil horizons) instead of single discrete ‘factors’ (soil pH) and that the microbial patterns can become a well-defined property of determined soils. We began exploring this biotic-abiotic dynamic by modeling soil microbial α-diversity using two orthogonal transects (~900 km each) across NSW. Soils were sampled from paired conserved and disturbed ecosystems. Soil biophysicochemistry was characterized using 16SrDNA/ITS metabarcoding and pedometric approaches. Soil microbial patterns and physicochemical attributes were assessed using linear and non-linear relationships (bootstraped regression trees models) whose output enabled the microbial mapping at 1km across NSW. These maps showed a higher diversity of soil microbes in western than eastern NSW. Despite this gradient, fungi and archaea were respectively lower and higher in Vertosols, whereas bacteria distribution was less clear. Our results suggested that microbial structural patterns relate to most pedological attributes and, the extent of this relationship varies according to the structural parameters analyzed (taxa composition, abundance, diversity metric). Therefore, microbial patterns are more consistent with grouped features defining soil gradients (soil types) rather than on individual soil properties. These conclusions will be supported by analyzing microbial and pedological dissimilarities (β-diversity) in a further research

Proceedings of the USDA-ARS workshop "Real world" infiltration

Compiled and edited by L.R. Ahuja and Amy Garrison.Includes bibliographical references.Proceedings of the 1996 workshop held on July 22-25, 1996 in Pingree Park, Colorado

Soil Erosion in a Highly Dynamic, Terraced Environment - the Effect of the Three Gorges Dam in China

Worldwide, soil erosion is one of the most pressing environmental problems of present times. Particularly, soil erosion triggered by overland flow and runoff seriously affects the productivity and stability of ecosystems. The loss of fertile topsoil and soil's water storage capacity, and the discharge of sediments and associated contamination of waterbodies due to diffuse matter transport of particle-bounded agrochemicals from cropland highly elicit call a for action to combat soil erosion for a future securing of food supply and high drinking water quality. Globally, China belongs to one of those countries most affected by soil erosion. Technical problems as well as high economic off-site damages and costs resulting from reservoir siltation and thus, reduced project's lifespan due to soil erosion are typical for numerous large-scale dam projects in China. In addition to the natural disposition to soil erosion, especially, anthropogenic impacts associated to the dam construction distinctly affect the soil erosion risk potential in the adjacent ecosystems. This can be exemplarily seen at the currently worldwide largest dam project, the Three Gorges Dam at the Yangtze River in Central China. This megaproject has been controversially discussed since its planning, and most recently since its construction and full operation in 2007. It contains the largest installed hydropower capacity worldwide, and is supposed to distinctly improve the river navigation and to secure the water supply to the northern country in the long-term. The realization of the dam project has already required massive resettlements of rural and urban population of more than one million people long before its start of operation. Additionally, large-scale land use changes, e.g., land reclamation for the road and settlement construction, for small scale subsistence farming and for cash crop production as well as shifts in land uses, on the steep sloping uphill-site above the impounded area are expected to considerably foster the soil erosion in the short- to long-term. Due to their partially direct connection to the stream network agriculturally used land with high soil erosion potential affects the water quality. Precise knowledge on the quality and quantity of soil loss, and its spatial and temporal variability can help to control the soil erosion by developing an adapted land use management and identifying conducive soil conservation measures, such as contour-aligned bench terraces. Under optimum conditions, bench terraces balance the geomorphic settings and anthropogenic use and can present a fair and sound basis for economic growth in mountainous areas. The focus of the present thesis lies on the risk potential of soil erosion by water in the newly created reservoir of the Three Gorges Dam. Therefore, the central research questions aimed at the natural soil erosion risk potential and the effect of the dam-induced land use dynamics on the dimension and spatial and temporal distribution of soil losses. Due to the data scarcity and limited access to the terrain, a further focus of the research conducted lied on the data-based regionalization of soil erosion factors to use as input in soil erosion modeling. The research was conducted in the subtropical Xiangxi catchment (3,200 km²) that was considered to adequately represent the Three Gorges Area in terms of physical settings and human interventions attributing to the dam project. The Xiangxi River joins the Yangtze River as a first class tributary approximately 40 km upstream the Three Gorges Dam. Due to the dam construction, the widely terraced landscape of the Xiangxi catchments is also affected by rapid, high land use dynamics with consequences on the slope stability. Particularly, the backwater area in the southern catchment area with the impounded lower reach of the Xiangxi River is characterized by steep to extremely steep sloping terrain and predominantly shallow soils with moderate to very high soil erodibility. Additionally, the very high rainfall erosivity increases the high physical vulnerability of the entire Xiangxi catchment. Between 1987 and 2007, a governmental-driven decrease of arable land and an increase of woodland and shrubland affected the northern headwater zone of the catchment. In the immediate reservoir area, the land use change from 1987 to 2007 was mainly controlled by a distinct conversion of arable land to orange orchards. Within the framework of this thesis, methods for data survey and data processing were tested and adapted in order to evaluate the risk potential of soil erosion. In addition, comprehensive field investigations focusing on soil erosion processes and on pedological properties and further erosion-relevant factors were conducted. Relevant parameters derived from remote sensing data and land use classifications as well as the documented land use change from 1987 to 2007 were used for the parameterization of the empirical soil erosion model RUSLE. This model was applied to estimate and evaluate the spatial distribution and dynamic of the soil erosion risk potential, and to spatially localize high-risk areas. The new conceptual model TerraCE was developed and tested for the identification and spatial analysis of different terrace conditions and their causes. By means of data mining approaches, a prediction of the spatial distribution of the identified terrace conditions was computed. By integrating environmental and anthropogenic indicators on the impact of the terrain and the human influence, the causes and the strength of disturbances on the terrace conditions, and thus terrace degradation were analyzed. During the observation period from 1987 to 2007, the Xiangxi catchment is generally characterized by a decrease of average annual soil losses and their maxima due to implemented environmental programs. However, a very high soil erosion risk potential in the entire catchment must be assumed. Frequency and intensity of soil erosion mainly concentrate in the backwater area at the lower reaches of the Xiangxi River. Here, land use changes, resettlements, and infrastructure construction have the highest impact. An inadequate construction of terraces that is not adapted to the local terrain conditions and an insufficient maintenance of the farming terraces can further strongly affect the soil erosion dynamic. Moreover, rapid ecosystem changes and an associated intensification and reclamation of terraces can lead to their degradation. The tempo of the land use dynamics hardly considers available capital and labor for the cost and time-consuming restoration and maintenance of terraces, mainly cultivated with oranges. The high increase of the reclaimed area for the orange production within very short term caused a surplus production and thus, a price decline on the local and regional markets. Due to the not very profitable sale of oranges, a lack of farmers' motivation and little or no capital are made responsible for the gradual worsening of the terrace conditions. As many of the resettled peasants, that were formerly used to farm the flat valley bottoms, are often not familiar with the new and difficult terrain settings and farming techniques, there is also a lack of knowledge on adequate terrace cultivation. Subsequently, inappropriate management of those terraces leads to an increase in the soil erosion The findings of the present thesis suggest designating the terraces as important, sensitive ecosystem service as they present - if properly maintained - a very effective soil erosion control and enable for a sustainable land use in the mountainous Xiangxi catchment and throughout the entire Three Gores Area. Considering the data scarcity in terms of spatial and temporal resolution, the results further show that soil erosion factors can be successfully regionalized and used for a valid soil erosion modeling. Against the background of ongoing research within the 'Yangtze Project' as well as further projected large dam projects at the Yangtze River and worldwide, the research conducted offers an important starting point for further research on the soil erosion risk potential and associated environmental threats, such as water pollution

Annual variation of bare arable soil areas on a global scale

Wydział Nauk Geograficznych i GeologicznychArable land around the world has a 12% share of the global land area. This thesis was created as a part of a project aimed at estimation of shortwave radiation reflected from those surfaces according to various scenarios based on the farming methods. This thesis was created as a part of a project aimed at estimation of shortwave radiation reflected from those surfaces according to various scenarios based on the farming methods. Its key element was the estimation of the bare soil area, defined for its spectral properties, as the area of arable land not covered by vegetation on more than 15% on its surface. In conventional agriculture, during the period immediately following the planting of crops, the soil stays bare until the newly planted crops reach defined above share of surface cover. This work focuses on estimating the periods of bare soil that occur after the planting of 13 major crops at the global scale; those selected crops are wheat, maize, barley, sorghum, soybeans, millet, cotton, rapeseed, groundnuts, potato, cassava, rye, and sugar beet. The supplementary objective of the study was to determine which soil groupings, and in what proportions, were bare during those periods. Arable land, divided into extensive agricultural regions located on six continents, was analyzed. The estimation of bare soil acreage was performed based on publicly available spatial datasets including the distribution of arable land in the world, crop calendars containing planting dates and the geographic distribution of crops. The arable land in the world was first divided into agricultural regions inspired by the division proposed by United States Department of Agriculture. For each region, average daily temperatures were used to predict plant growth stages. For each crop within a region, the planting date was used as the beginning of the bare soil period, which ended when it reached a stage where at least 15% of the surface was covered by vegetation. The aggregated periods concerning every crop within any given region resulted in an annual variation of bare soil area. The acreages of soil grouping used in agriculture for any region were then extracted based on the location of arable land and the region’s boundaries.The global annual variation of bare soil area shows that the maximum level occurs around the 140th day of the year (DOY) (middle of May), influenced primarily by the planting of crops occurring in the northern hemisphere. Up to 1.5 million km2of soil surface stays bare at that time. Centered on that maximum is a period of bare soil lasting for almost four months, between the 92nd DOY and the 200th DOY (early April and end of July), when two lesser maxima were observed, of around 900,000 and 700,000 km2, respectively. The equivalent of that period, resulting from planting in the southern hemisphere, starts around the 330th DOY (middle of November) and lasts for about a month, reaching almost 400,000 km2. The other distinguishable episode of bare soil in the southern hemisphere was noted between the 15th and the 25th DOY (second half of January) when its area reached 100,000 km2. Asia is the super region with by far the largest area of arable land and consequently, it sports the highest acreage of bare soil. During the aforementioned maximum in the northern hemisphere occurring around the 140th DOY, the Asian super region contributes around 700,000 km2 of bare soil, which is almost half of the bare soil area for the whole northern hemisphere at that time, with Lithosols, Cambisols, and Gleysols being the major soil groupings that stay bare. In Europe, two distinct periods of bare soil were found; during the first, starting around the 40th DOY (middle of February) and lasting until the 150th DOY (end of May), the steady increase of the bare soil area lasts until the 140th DOY (middle of May) when it reaches almost 500,000 km2, after which a rapid decline was observed. The second, manifesting two and a half months later, lasts between around the 230th and the 290th DOY (middle of August to middle of October), and exceeds 100,000 km2. Chernozems, Cambisols, and Luvisols are dominant soil groupings on arable land in Europe. Similar trends, related to the European bare soil areas, were found in the North American super region, where a period of maximum bare soil area occurs in late spring, and a second period, characterized by a much smaller area, follows the main one three months later. The maxima coincide with the aforementioned ones in Asia and Europe, reaching 300,000 km2 of bare soil around the 140th DOY. Similar to Europe, the second period sports a much smaller bare soil area, short of 30,000 km2. The dominant soil groupings in agricultural use in North America are Kastanozems, Luvisols, and Chernozems. Africa is a super region whose area is divided between both northern and southern hemispheres, which shows in the annual variation of its bare soil area. Three distinct periods were found there, the major one around the middle of a year lasted for about two and a half months, between the 167th and the 230th DOY (middle of June to middle of August) with the bare soil area being up to almost 400,000 km2. The other peak occurs about a month and a half earlier, between the 95th and the 115th DOY (roughly the month of April) and is characterized by a bare soil area exceeding 120,000 km2. The last notable episode of bare soil in Africa manifests itself between the 317th DOY and the 10th day of the following year (middle of November to the middle of January), with the area of soil uncovered by vegetation reaching almost 100,000 km2. Luvisols together with Arenosols, followed by Vertisols, are the most extensively farmed soil groupings in Africa. The majority of arable land in the southern hemisphere is found in the South American super region, which is reflected in the annual variation of bare soil area, which is similar to that of the whole southern hemisphere. The maximum lasts for around two weeks, between the 330th and the 345th DOY (end of November to the middle of December), when almost 500,000 km2 of arable soil is bare. A secondary peak was observed between the 15th and the 30th DOY (second half of January), sporting around 100,000 km2 of bare soil area. Ferrasols is the most commonly farmed soil grouping in the region, followed by Phaozems and Luvisols. In Oceania, the maximum area of bare soil slightly exceeds 25,000 km2 for about two weeks in the first half of June, followed by a rapid decline. A secondary period is characterized by a longer duration but the smaller area, lasting between the 313th and the 14th DOY (middle of November to middle of January) with about 5,000 km2 of arable land which is not covered by vegetation at that time. Luvisols are the dominant soil grouping under cultivation in Oceania, followed by Planosols, Solonetz, and Vertisols. The obtained variations of bare soil areas together with the corresponding share of soil groupings for all regions were used in other work in order to estimate the amount of shortwave radiation reflected from those surfaces according to various scenarios based on the farming methods.Grunty orne stanowią około 12% powierzchni lądów na całym świecie. Niniejsza praca powstała w ramach projektu dążącego do oszacowania ilości promieniowania krótkofalowego odbijanego od tych powierzchni. Kluczowym jej elementem było oszacowanie areału odkrytej gleby, definiowanej ze względu na jej właściwości spektralne, jako powierzchni gruntów ornych niepokrytych roślinnością w stopniu większym niż 15%. W przypadku rolnictwa konwencjonalnego, w okresie bezpośrednio po sianiu lub sadzeniu roślin gleba pozostaje odkryta, dopóki nowo zasiane lub zasadzone rośliny nie osiągną fazy wzrostu powodującej pokrycie powierzchni w wyżej zdefiniowanym stopniu. Praca ta koncentruje się na oszacowaniu okresów kiedy gleba pozostaje odkryta, które występują po sianiu lub sadzeniu 13 głównych upraw w skali globalnej; te wybrane uprawy to pszenica, kukurydza, jęczmień, sorgo, soja, proso, bawełna, rzepak, orzeszki ziemne, ziemniaki, maniok, żyto i burak cukrowy. Celem badania było ustalenie, które główne grupy glebowe (major soil groupings wg definicji FAO–UNESCO) oraz w jakich areałach pozostają odkryte. Przeanalizowane zostały grunty orne podzielone na regiony rolnicze położone na sześciu kontynentach. Oszacowanie areału odkrytej gleby przeprowadzono przy użyciu publicznie dostępnych zbiorów danych przestrzennych, w tym rozmieszczenia gruntów ornych na świecie, geograficznego rozmieszczenia upraw oraz kalendarzy upraw zawierających daty sadzenia. Używane zbiory danych zostały w pierwszej kolejności podzielone na regiony rolnicze zainspirowane podziałem zaproponowanym przez Departament Rolnictwa Stanów Zjednoczonych. Dla każdego z tych regionów zastosowano średnie dzienne temperatury w celu oszacowania etapów wzrostu roślin. Dla każdej uprawy w regionie data sadzenia została wykorzystana jako początek okresu występowania odkrytej gleby, który kończy się, gdy osiągnie etap, w którym gleba zostaje pokryte roślinnością. Zagregowane okresy dotyczące każdej uprawy w danym regionie posłużyły do ustalenia rocznej zmienności powierzchni odkrytej gleby. Areały głównych grup glebowych wykorzystywanych w rolnictwie dla każdego z regionów zostały następnie obliczone na podstawie lokalizacji gruntów ornych i granic regionu. Analizując wszystkie grunty orne na świecie, maksymalny poziom odkrycia występuje około 140 dnia roku (day of year - DOY);(połowa maja), i jest spowodowany przede wszystkim przez sianie oraz sadzenie roślin uprawnych na półkuli północnej. W tym czasie do 1,5 mln km2 powierzchni gruntów ornych nie jest pokryta przez rośliny. Wyżej opisane maksimum występuje podczas okres odsłoniętej gleby trwającego przez prawie cztery miesiące, między 92 DOY a 200 DOY (początek kwietnia a koniec lipca), kiedy zaobserwowano dwa pomniejsze maksima, odpowiednio około 900 000 i 700 000 km2. Odpowiednik tego okresu, wynikający z siania oraz sadzenia na półkuli południowej, zaczyna się około 330 DOY (połowa listopada) i trwa około miesiąca, osiągając prawie 400 000 km2. Inny wyraźnie widoczny okres odkrytej gleby na półkuli południowej odnotowano między 15 a 25 DOY (druga połowa stycznia), kiedy jego powierzchnia osiągnęła 100 000 km2. Azja to kontynent o zdecydowanie największym areale odkrytej gleby wynikający ze zdecydowanie największej powierzchni gruntów ornych. Podczas wspomnianego maksimum na półkuli północnej, występującego około 140 DOY, azjatycki region odpowiada za około 700 000 km2 odkrytej gleby, a więc prawie połowę powierzchni odkrytej gleby dla całej półkuli północnej w tym czasie, z Lithosols, Cambisols i Gleysols jako głównymi grupami gleb, które pozostają odkryte. W Europie znaleziono dwa odrębne okresy odkrytej gleby; podczas pierwszego, rozpoczynającego się około 40 DOY (połowa lutego) i trwającego do 150 DOY (koniec maja), stały wzrost powierzchni odkrytej gleby trwa do 140 DOY (połowa maja), kiedy osiąga ona prawie 500 000 km2, po czym następuje gwałtowny spadek tego areału. Drugi, zaczynający się dwa i pół miesiąca później, trwa od około 230 do 290 DOY (od połowy sierpnia do połowy października) i przekracza 100 000 km2. Chernozems, Cambisols i Luvisols są dominującymi grupami glebowymi na gruntach ornych w Europie. Podobne tendencje jak w przypadku odsłoniętych gleb na kontynencie europejski zanotowano w Ameryce Północnej, w przypadku której okres największej powierzchni odkrytej gleby występuje późną wiosną, a drugi okres, obejmującym znacznie mniejszy areał, następuje trzy miesiące później. Maksymalne wartości występują w podobnym okresie jak w wyżej wymienionych Azji i Europie, osiągając 300 000 km2 odkrytej gleby około 140 DOY. Podobnie jak w Europie, drugi okres charakteryzuje się znacznie mniejszą powierzchnię odkrytej gleby, poniżej 30 000 km2. Dominującymi grupami glebowymi uprawianymi w Ameryki Północnej są Kastanozems, Luvisols i Chernozems. Afryka jest kontynentem zajmującym półkulą północną, jak i południową, co jest odzwierciedlone w rocznym przebiegu areału odkrytej gleby. Wyróżniono tam trzy osobne okresy, największy z nich występuje w połowie roku i trwa około dwóch i pół miesiąca, między 167 a 230 DOY (od połowy czerwca do połowy sierpnia), podczas którego powierzchnia odkrytej gleby osiąga prawie 400 000 km2. Drugi szczyt występuje około półtora miesiąca wcześniej, między 95 a 115 DOY (w kwietniu) i charakteryzuje się areałem odkrytej gleby przekraczającym 120 000 km2. Ostatni znaczący okresy odkrytej gleby w Afryce ustalono między 317 DOY a 10 dniem następnego roku (od połowy listopada do połowy stycznia), przy czym odkryty areał gleby sięga prawie 100 000 km2. Luvisols wraz z Arenosols oraz Vertisols, są najbardziej ekstensywnie uprawianymi grupami glebowymi w Afryce. Roczna zmienność powierzchni odsłoniętej gleby na kontynencie Ameryki Południowej ma podobny przebieg jak w przypadku całej półkuli południowej. Maksimum areału odsłoniętej gleby trwa przez około dwa tygodnie, między 330 a 345 DOY (koniec listopada do połowy grudnia), kiedy prawie 500 000 km2 gruntów ornych pozostaje odkrytych. Drugi szczyt zaobserwowano między 15 a 30 DOY (druga połowa stycznia), w którego trakcie około 100 000 km2 gruntów ornych jest odsłoniętych. Ferrasols są najczęściej uprawianą grupą glebową na kontynencie, a następnie Phaozems i Luvisols. W Oceanii maksymalny areał odkrytej gleby nieznacznie przekracza 25 000 km2 przez okres około dwóch tygodni w pierwszej połowie czerwca, po czym następuje jego gwałtowny spadek. Drugi okres charakteryzuje się dłuższym czasem trwania, ale mniejszym areałem, utrzymującym się od 313 do 14 DOY (od połowy listopada do połowy stycznia) z około 5000 km2 gruntów ornych, które nie są w tym czasie pokryte roślinnością. Luvisols są dominującą grupą glebową pod uprawą w Oceanii, a następnie Planosols, Solonetz i Vertisols.project 2014/13/B/ST10/02111, financed by the Polish National Science Cente

Status and Dynamics of Forests in Germany

Life sciences; Ecology ; Forestry; Soil science; Soil conservation; Sustainable development; Geobiolog