Pedological Data Research Articles

An Approach to Assess the Impact of High Biaxial Photovoltaic Trackers on Crop Growth and Yield

The growing need for producing renewable energy such as photovoltaic electricity, and the mitigation of the increasing occurrences of heatwaves and drought affecting annual crops, could be addressed by the installation of agrivoltaic systems. Depending on pedoclimatic context, cultivated crop, solar panels technology and implementation configuration, solar panels shading can improve or reduce crop growth and yields. Among photovoltaic installations, solar trackers might have a high development potential. These photovoltaic panels are mounted on a vertical axis at a 7m height. Thanks to their height, their biaxial moving capacity, their small anchoring surface and their punctual structure making plants design easily adaptable to agricultural constraints, they can fit with all types of agricultural systems. The aim of this study was to evaluate the impact of such trackers on crop growth and yields. For this purpose, a set of 6 different fields crop located in western France were studied. Crop phenology, height and yield were investigated. Results showed a delay in crop development near the trackers that was overcome late in the crop cycle, near harvest. For crop height and crop yield, the results showed important spatial variability but without clear trend related to the tracker shadow. The results are discussed in the light of new perspectives, including the consideration of microclimatic and pedological data to better explore the effects of trackers on plant growth and development, the measurement of morphological and physiological traits of plants, the accounting of a multi-trackers effect implemented on the same site, the temporal dynamics of the effect of a tracker.

Evaluation of the physical properties of fresh and dried peppercorns grown in Côte d'Ivoire

The pepper plant (piper nigrum) is mainly grown for its fruit. Indeed, its fruits are mainly used as spices and condiments. The objective of this study was to determine the physical properties of fresh and dried pepper domesticated in Côte d'Ivoire. Physical parameters such as density, diameter and color of fresh and dried pepper seeds were analyzed. Samples of fresh and dried pepper were collected in the various production localities selected on the basis of pedological data. In addition, sampling was carried out over two (2) years. The results obtained indicate a high density of fresh and dried pepper in samples taken in the localities of Niablé (1004 kg/m3) and PK 103 (1006.4 kg/m3). The largest diameters of fresh and dried pepper were observed in the Assouba (5.4 mm) and N'douci (5.1 mm) samples. The highest luminance values for fresh and dried pepper were obtained in the Guibéroua (14.67) and Danane (22.01) samples. The highest chromatid a* values for fresh and dried pepper were obtained in samples from Assouba (3.69) and Guibéroua (4.06), and the highest chromatid b* values for fresh and dried pepper were recorded in samples from Guibéroua (6.85) and Danane (4.97). Finally, the results obtained highlight the importance of physical parameters such as density, diameter and color in the marketing of fresh and dried pepper.

Pedological data for the study of soils developed over a limestone bed in a humid tropical environment.

Lithological characteristics interact with other factors of soil formation to define soil genesis. This becomes more interesting as data on the mineral and elemental oxide components of soils developed from limestone are rarely available in the humid tropical environment. The present study investigated the elemental oxide content, forms of sesquioxides, and clay mineral species in some limestone soils. Soil samples were obtained from three (3) crestal soil profile pits and analyzed for elemental content by the use of an X-ray fluorescence spectrometer, and sesquioxide forms by inductively coupled plasma-mass spectrometer. Analyses were done in triplicates. The mineralogy of the clay fraction was determined on the A, B, and C horizon samples using an X-ray diffraction technique. The occurrence of SiO2 (203-277g/kg), Al2O3 (65-105g/kg), and Fe2O3 (14-95g/kg) in substantial amounts over MnO2, ZrO2, and TiO2 with negligible quantities of CaO suggested comparatively more developed soils in the Agoi Ibami and Mfamosing tropical rainforests. Crystalline form of Fe was dominant over amorphous form, with indications of the co-migration of dithionite Fe with clay to the B horizons of the soils. Quartz, kaolinite, montmorillonite, and chlorite-vermiculite-montmorillonite interlayered minerals dominated the clay mineralogy of the studied soils. Mineral transformation places the soils at the transitory stage from the intermediate to the complete stage of soil development. The expanding clay minerals are most likely to increase plant nutrient adsorption and soil fertility status to accommodate the cultivation of a wider range of crops.

GIS-Based Geopedological Approach for Assessing Land Suitability for Chestnut (Castanea sativa Mill.) Groves for Fruit Production

The identification of mountainous areas suitable for chestnut stands for fruit production (CSFP) is raising increasing interest among researchers. This work aimed to (i) identify the areas suitable for CSFP shown in a land suitability map easy to read by land planners, and (ii) propose a remote-sensing-based methodology able to identify the lands currently under cultivation for CSFP. This study was conducted using the QGIS software for the Municipality of Castel del Rio, Emilia-Romagna Region, Italy. To obtain the land suitability map, topographic, lithological, and pedological data were acquired, and the areas located between 200 and 1000 m of altitude, with north exposition, a slope < 20°, sandstone-based lithology, and soils with dystric features were selected. The currently cultivated areas for CSFP were identified through remote-sensing images of the early spring period, which were delineated and georeferenced. The findings showed that only 10% of the whole study site area can be considered suitable for CSFP. Further, most of the currently cultivated CSFP (59%) are in non-suitable areas characterised by high slope gradients. The methodology applied in this study can easily provide detailed information about the suitable areas for CSFP and the areas currently cultivated with chestnut, thus allowing accurate land-use planning and land conservation.

Mapping of restrictive factors of land in the hydrographic basin of the middle section of the Paraíba River

This work aimed to identify and map the pedological restrictions of the lands in the middle course of the Paraíba River. For this, GIS SPRING, digital soil map, and the Agricultural Zoning of the State of Paraíba information were used. From these, pedological data were extracted to classify the soils based on salinity/sodicity, effective depth, stoniness, fertility, erosion, drainage, and texture. Data were interpreted and classified according to soil-restricting factors (null, light, moderate, strong, very strong, and extremely strong). It was observed that the most common land use restriction factors in the strong class were texture, effective depth, and stoniness; in the moderate class, erodibility, slope, and fertility; in the light class, slope; and in the null class, salinity and drainage.

Fertility capability classification (FCC) of soils of a lower Brahmaputra valley area of Assam, India

Fertility capability classification (FCC) is a system of classification which uses pedological data of soils and coverts it into capability classes based on major fertility constraints portrayed by the soils. The present study was aimed to classify the soils major landforms of a lower Brahmaputra valley region of Assam, India in to FCC classes, to suggest specific management practices in order to overcome the fertility constraints and improve the crop productivity.The major strata types used were found to be loamy top soil, 'L' and clayey top soil 'C'. The sub-strata type found were loamy sub soil, 'L' and clayey sub soils, 'C'. The major condition modifiers or the major fertility constraints were found to be Al toxicity 'a’ and 'a-', high leaching potential, 'e', low nutrient reserves 'k' and 'g' waterlogging. The paddy soils of alluvial plains were classified into La-eg and Lg+a-e. The tea growing soils of younger alluvial plains were classified into Car+e. The non-paddy soils of alluvial plains were categorized as Ca-gke. The soils of uplands and inselberg were categorized into LCae class. The study revealed that FCC classification can successfully bring out the soil fertility constraints and can be very much helpful in soil fertility management for sustainable crop productions.

Environmental changes in southeastern Europe over the last 450 ka: Magnetic and pedologic study of a loess-paleosol profile from Kaolinovo (Bulgaria)

Magnetic properties are sensitive paleoenvironmental proxies frequently used in studies of loess paleosol profiles. Understanding precisely the magnetic recording of soil responses to environmental and climatic changes needs combining pedologic data and geophysical proxies. Here we present a new high-resolution study of a 450 ka old loess-paleosol profile from low Danube loess area at Kaolinovo (NE Bulgaria). The profile consists of Holocene soil S0 on top, three paleosol units (S1, S2, S3–S4) and the intercalated loess horizons L1 to L4. Mineral magnetic and rock magnetic data together with pedological parameters (particle size distribution, total, crystalline and amorphous iron, soil organic carbon, total nitrogen, cation exchange capacity, carbonate content) show systematic variations in response to environmental changes. Principal component analyses carried out separately on magnetic mineralogy, rock magnetic and pedological variables reveal the complex response of loess – paleosol sediments to changes in source material and climate. The observed sharp shift in coercivity of mineral magnetic carriers at depth of the third loess L3 marks the change from low-coercivity mineral assemblages in older units to higher coercivity in the last three loess paleosol couplets (L1-S0, L2-S1, L3 – S2). This boundary is related to both dust source change and increased climate aridity. The observed spikes in concentration-dependent magnetic parameters in the lowermost part of the profile and particular magnetic and pedologic signature of the oldest deposits (S3–S4 pedocomplex) suggest that it may result from tephra additions in the studied loess-paleosol sequence, tentatively correlated to cryptotephra layers in other terrestrial archives in the region like Tenaghi Philippon and lake Ohrid sedimentary sequences. This work demonstrated that using PCA tool for studying the significance and objective inter-relationships of multiple mineralogical, mineral magnetic and pedological characteristics along depth of loess – paleosol profiles is an exemplary approach for revealing the underlying sedimentary and environmental processes.

Paleolakes, archaeology, and late Quaternary paleoenvironments in northwestern Mongolia

AbstractThe climatic, hydrographic, and environmental regimes of terminal Pleistocene and Holocene northwestern Mongolia are reconstructed using archaeological and pedological data sets at Bayan Nuur, a lake on the northwestern perimeter of the Altan Els dune field in eastern Uvs Province, Mongolia. The archaeological data consist of land-use patterns controlled for time via time-sensitive, diagnostic artifacts. The pedological data consist of soil classifications and radiocarbon dating of paleosols that track lake levels and water table. These data are combined using a geographic information system (GIS) to ascertain site and paleosol geographic relationships to modern lake levels at Bayan Nuur. They point to a more xeric Younger Dryas than previously recognized, significant Holocene lake regressions, and to Mid- to Late Holocene lake standstills/transgressions, the scale of which had previously been unrecognized. Combined, these data point to a complex late Quaternary picture of paleoclimate and paleoenvironment across the region and the importance of using multiple proxies, including archaeological data, in paleoecological reconstructions.

A mathematical model for determining engineering soil classifications from pedological data

Various pedological soil classification systems exist worldwide, including an internationally accepted system and various national systems, many of which have been incorporated into databases that include maps. Various physical and chemical soil properties are used for classifying soils according to these pedological systems. This paper proposes an approach which may be used to determine the engineering properties of soils from the physical and chemical properties that are used to pedologically classify soils by systems, and, in particular, the South African Binomial System. These engineering properties include the USCS and AASHTO classification groups which may, in turn, be used as a means of rapidly determining the general suitability of areas for proposed development, particularly during the reconnaissance investigation stages of transportation route locations and township developments, with a resultant saving of time and money. The model was verified using data from the study area, as well as from an area located approximately 190 km from the study area. A total of 88% of the classification groups determined by the model, in the study area, were correct. Furthermore, only 6% of the classifications were incorrect by a maximum of two groups. The classifications determined for the soils outside the study area were all correct.

Utilising Land Type data for geotechnical investigations

In South Africa, a Land Type Survey (LTSS) has been conducted of the entire country. The information available from the LTSS is readily and inexpensively made available to the public (in the form of maps and accompanying memoirs). This survey includes information on the climate, terrain and soils. The soil information given includes qualitative data (such as pedological classifications, soil profiles and soil types), as well as quantitative physical and chemical properties of representative soils tested. Such information is used primarily for agricultural purposes. This paper proposes an approach for inferring information, of relevance in reconnaissance geotechnical engineering surveys, from Land Type data, to supplement geotechnical investigation data. The proposed procedure was verified using actual information from a geotechnical report. This investigation indicated that general engineering properties can be inferred from qualitative pedological data. In addition, statistically significant engineering properties (including the grading, Atterberg Limits and the USCS and AASHTO classifications) were determined from quantitative pedological data, in 86% of cases, for the soils considered. It is evident from this research that data from the Land Type survey data can be successfully used for geotechnical investigation purposes for certain developments (such as roads and townships) where the depth of interest is relatively shallow.

SOIL THICKNESS SPATIAL DISTRIBUTION INFLUENCE ON FACTOR OF SAFETY EQUATION

Mass movements occurrences are well studied, however there are still possible improvements regarding their factor of safety simulation. This paper focus on the influence of spatialized pedological data and geotechnical data, two of the major limitations for this type of modeling. Numerous mass movements were triggered by an extreme precipitation event in southern Brazil, when the rainwaters reached 300mm in just 24 hours. A local watershed was chosen for field campaigns to supply a safety factor model and show the direct influence of field data on the result efficiency. For this, four different scenarios were created using combination of field data and spatialized soil thickness throughout the watershed area. The results showed an improve of 12% on the simulation efficiency when compared to a homogeneus soil thickness and average geotechnical values scenario, showing the importance of field studies for factor of safety simulations.

Geotechnology applied to land classification in areas of the Atlantic Forest in southeastern Brazil

The objective of this study was to classify the lands of a micro-watershed located in the Atlantic forest biome, in a region of rough relief, in the use capacity system using geotechnology resources and indicate uses for the lands according to their suitability. The theoretical basis of the Manual for Utilitarian Survey and Classification of Land in the Use Capacity System with adaptations for areas of rough relief was adopted. The study was carried out from the survey of topographic information to construct the altimetric map of the watershed, followed by the survey of the physical environment, especially water erosion, description of soil profiles and collection of samples. The parameters effective depth, texture, permeability, slope, erosion, fertility, and land use were evaluated. Based on the pedological data and on the use of applied geotechnology, the soil map was created, and the lands of the watershed were classified and mapped in the use capacity system. After interpretation of the survey products, it was verified that in rough relief, slope is the predominant factor to determine the classes of land use, as it outweighs the other parameters evaluated. Land classification land with the use capacity system promotes optimization in the use of areas with agricultural areas and preservation of those destined for conservation.

Environmental covariates improve the spectral predictions of organic carbon in subtropical soils in southern Brazil

Including environmental covariates, when available, can be a valuable strategy for achieving higher soil predictive performance, but it is still unknown whether environmental data should be used either as covariates, combined with Vis-NIR spectra, to predict soil organic carbon (SOC) or as criteria to stratify a soil spectral library (SSL). We hypothesized that the performance of Vis-NIR spectroscopy in predicting SOC could be improved by the inclusion of auxiliary environmental data as covariates in Cubist models and thereby overcome the data stratification limitations. To test this, we evaluated six covariate sets, in which the following covariates were combined: spectral data, spectral classes, pedological data, and environmental data calibrated using Cubist models. An SSL composed of 2,461 samples from southern Brazil was used to calibrate models considering different sets of covariates. Model 1 included Vis-NIR reflectance (350–2500 nm), and Model 2 included Vis-NIR reflectance and spectral class. Model 3 included physiographic region, land-use/land-cover (LULC), climate, parent material, elevation, and clay content, while Model 4 included the parameters from Model 3 with the addition of Vis-NIR reflectance. Model 5 included Vis-NIR reflectance, spectral class, physiographic region, LULC, and soil textural class, while Model 6 included Vis-NIR reflectance, spectral class, physiographic region, LULC, climate, parent material, elevation, and clay content. The inclusion of environmental data as covariates along with Vis-NIR improved the predictive performance for SOC. Among the six covariate sets tested, the set including all covariates (Model 6) showed the best performance, improving the accuracy in prediction by 12% and reducing the prediction error (RMSE) by 22% compared to Model 1. Model 6 was the most accurate, and the input of environmental data as covariates is a promising strategy to achieve more accurate SOC predictions. Thus, covariates (e.g. elevation, clay content) that correlate with SOC improved the prediction accuracy of Vis-NIR spectroscopy models. The Cubist model was able to achieve similar accuracy and overcome the limitations presented by the stratification strategy documented in the literature by preventing the reduction of the sample size in the calibration of the models.

Avaliações de Funções de Pedotransferência para Solos Brasileiros

Funções de Pedotransferência (FPT) são modelos matemáticos que estimam propriedades do solo de difícil medição por meio de variáveis mais acessíveis, gerando otimização de tempo e de recursos financeiros. Neste estudo, seis Funções de Pedotransferência, fundamentadas na equação de Van Genuchten (1980), foram analisadas para a predição da umidade volumétrica de solos brasileiros, com dados da base global Soil Data Task. Aplicadas para as pressões de 0, 0.01, 0.03, 0.10, 0.20, 0.50, 2.50 e 15.0 bar, os valores resultantes das equações foram comparados com as umidades volumétricas medidas por meio de cinco parâmetros estatísticos: índice de confiança, erro quadrático médio, razão dos desvios, eficiência de modelagem e coeficiente de massa residual. Das funções estudadas foi possível verificar que a função de B4v foi a que apresentou melhores resultados, enquanto que a de RB obteve o menor desempenho e que a eficiência de uma FPT está relacionada à dois fatores: semelhança entre os dados pedológicos do solo estudado e os utilizados no desenvolvimento da função e a quantidade de variáveis analisadas. Evaluations of Pedotransfer Functions for Brazilian SoilsA B S T R A C TPedotransfer Functions (FPT) are mathematical models that estimate difficult-to-measure soil properties through more accessible variables, generating optimization of time and financial resources. In this study, six Pedotransfer Functions, based on the equation of Van Genuchten, analyzed for the prediction of volumetric moisture of Brazilian soils, with data from the global database Soil Data Task. Applied for pressures of 0, 0.01, 0.03, 0.10, 0.20, 0.50, 2.50 and 15.0 bar, the resulting values of the equations were compared with the measured volumetric moistures through five statistical parameters: confidence index, mean square error, deviation ratio, modeling efficiency and residual mass coefficient. Of the functions studied it was possible to verify that the FPT proposed by Barros, with 4 parameters, was the one that presented the best results, while that of Rawls and Brakensied obtained the lowest performance. It has been observed that the efficiency of a FPT is related to two factors: a) similarity between the pedological data of the soil studied and those used in the development of the FPT, and b) the amount of variables analyzed.Keywords: Estimation; Soil Physical Properties; Soil Moisture Volumetric

Changes in high-intensity precipitation on the northern Apennines (Italy) as revealed by multidisciplinary data over the last 9000 years

Abstract. Several record-breaking precipitation events have struck the mountainous area of the Emilia–Romagna region (northern Apennines, Italy) over the last 10 years. As a consequence, severe geomorphological processes such as debris avalanches and debris flows, shallow landslides, and overbank flooding have affected the territory, causing severe damage to human-made structures. The unusual intensity of these phenomena prompted an investigation into their frequency in the past, beyond instrumental time. In the quest for an understanding of whether these phenomena are unprecedented in the region, peat bog and lake deposits were analyzed to infer the frequency of extreme precipitation events that may have occurred in the past. We present the results of a dedicated field campaign performed in summer 2017 at Lake Moo in the northern Apennines, a 0.15 km2 peat bog located at an altitude of 1130 m a.s.l. During the extreme precipitation event of 13–14 September 2015, several debris flows generated by small streams affected the Lake Moo plain. In such a small drainage basin (<2 km2), high-density floods can be triggered only by high-intensity precipitation events. The sedimentary succession (ca. 13 m thick) was studied through the drilling of two cores and one trench. The sequence, characterized by clusters of coarse-grained alluvial deposits interbedded with organic-rich silty clays and peat layers, was analyzed by combining sedimentological, pollen, microanthracological and pedological data with radiocarbon dating (AMS 14C) in an innovative multidisciplinary approach for this area. Original data acquired during the field campaign were also correlated with other specific paleoclimatic proxies available in the literature for the northern Apennines area. We discover that the increase in extreme paleoflooding, associated with coarse-grained deposits similar to the ones observed recently, correlates well with the warm phases of the Holocene Thermal Maximum and with the ongoing warming trend observed that started at the beginning of the last century.

Technogenic deposits formed from dredged sediments deposition: toxic effects on earthworms

Dredged sediments are often disposed on land areas and can cause adverse effects on soil biota, since these materials generally may contain toxic agents. This work examines the ecotoxicological effects on earthworms exposed to technogenic deposits formed from the deposition of dredged sediments from an urban tropical lagoon. Such evaluation supports the understanding of the ecological effects derived from dredged sediments in the tropics, as well as the influence of soil properties in the toxicity. To simulate dredged sediment disposal under tropical conditions, a dredged sediment sample from the Rodrigo de Freitas Lagoon (Rio de Janeiro, RJ, Brazil) was mixed with a Gleysol (a typical organic tropical soil) to obtain the following doses: 0, 6, 12, 18, and 24%, where 0% = pure Gleysol. Acute and avoidance bioassays with Eisenia andrei were applied to these mixtures following standard protocols (ISO). Physical, chemical, and mineralogical characterization of the materials and metal determination in the test mixtures were performed to support the interpretations of ecotoxicological data. Metal concentrations in the test mixtures were generally in accordance with the limits defined by Brazilian law. Earthworm mortality was significant in doses ≥ 8% (LC50 = 7.1%), while doses ≥ 2% caused avoidance responses (EC50 = 1.7%, p < 0.05). The salinity in 8% treatment is similar to the salinity levels described by the literature that cause adverse effects on earthworms, suggesting that salinity played a key role in the toxicity. Earthworm biomass increased (p < 0.05) when the organisms were exposed to non-lethal doses, and this is probably due to water bioaccumulation related to high contents of salts. When comparing the toxicity found in this work with data obtained with other tropical soils, one could suppose that Gleysol mineralogy seems to control the bioavailability of salts and metals. The possible formation of technogenic soils (constructed soils) due to land deposition of dredged sediments may potentially compromise natural soil fauna. In this particular case, soil mineralogy, salinity, and metals played a relevant role in the toxicity to earthworms. The development of approaches that can integrate ecotoxicological, ecological, and pedological data is urgent for better understanding the damages associated with the disposal of dredged sediments in tropical lowlands areas.

GIS application in abiotic risks regionalization for spring barley

In recent years, there has been a noticeable uneven distribution of rainfall in Central Europe during the main vegetation season of most field crops. The rising air temperatures also increase the evapotranspiration demands of the environment and increase the frequency and length of heatwaves, which is a stress factor for plants. Using the GIS procedures, we identified the areas of significant abiotic risks occurring during the critical growth stages of spring barley (high air temperatures at the time of tillering and lack of soil moisture from the beginning of flowering to yellow ripening) with potential impact on grain yield in the Czech Republic. Unique datasets, including i) meteorological data, ii) phenological data, iii) pedological data, iv) land-use data, and v) geographic data, have been integrated and analysed using the sophisticated ArcGIS software environment. The method used in this study is universally applicable and allows comparisons at the local, regional, and supra-regional levels. The identification of risk areas will allow for a) finding tolerant varieties from problematic areas, b) locating the use of these varieties in risk areas and c) recommending and implementing adequate farming practices to reduce the impact of risk abiotic stressors on spring barley under current climate conditions. This will allow accurate estimation of weather impacts on spring barley grain yield in a particular year and precise application of countermeasures leading to reduced negative impacts on yield and the quality of spring barley production. Using the data and methods presented, we identified areas that correspond in good accordance to areas with spring barley yield deficits in dry years.

Farming the Great Sage Plain: Experimental Agroarchaeology and the Basketmaker III Soil Record

AbstractThis article draws together data from two of Crow Canyon Archaeological Center's recent research projects and combines these data in new ways to elucidate the relationship between Mesa Verde region soil development and non‐irrigation farming practices. The Pueblo Farming Project (PFP) seeks to preserve traditional farming knowledge and educate the public concerning traditional farming and the place of corn in Pueblo cultures. The Basketmaker Communities Project (BCP) focuses on understanding the Basketmaker III Period and the development of Early Pueblo communities. Pedologic data from each of Crow Canyon's experimental gardens, a mature piñon–juniper forest, and four Basketmaker sites reveal patterns of soil development. The Mesa Verde Loess‐based soils become indurated with use and must be remediated, fallowed, or abandoned, with implications for site choice and residence time. Induration and productivity appear to vary inversely over time, with impacts due to management, vegetation, exposure, and use‐life. Understanding the interplay of climate, cultural practice, and pedogenesis is, therefore, key to deciphering this geocultural record and pursuing agricultural sustainability in this region. We present a framework for unifying these lines of investigation and to facilitate moving future studies forward together.

The hunter-gatherer site BES II (Jacaré-Guaçu River low terraces, central Sao Paulo state, Brazil): Interface with geomorphical and environmental fluctuations of the Pleistocene-Holocene transition

The lithic site Boa Esperança II (BES II), in the São Paulo segment of the Brazilian Plateau, next to the boundary between the cities of Araraquara (SP) and Boa Esperança do Sul (SP), presents a collection of almost 2,000 lithic artifacts (predominantly chert and sandstone), being interpreted as a settlement of diversified functions with possibly continuous or successive occupation. In this work, we approach the site based on interface of its insertion in the regional physical-environmental context - with emphasis on the interface with relief frames, surface structure study and estimated geomorphic sequences of the alluvial plain of Jacaré-Guaçu river - and techno-typological analysis. It was verified that the BES II artifacts are distributed along vertical profiles and relief pictures lined by records that mark the transition from semi-arid conditions to others of increasing humidity, successive oscillations of base levels and modifications of fluvial regimes (ephemeral channels passing to perennial channels of different hydrological meandrings patterns), indicating that human occupation has dealt with conditions of quite distinct landscapes between the Late Pleistocene and the Holocene. Local lithic industry would have taken advantage of attributes derived from these modifications in the landscape over time - in particular the exposure of gravels of large river pebbles deposited by torrential ephemeral channels. The past abundance of raw material of fluvial origin would have contributed to the location of the site in the regional geomorphological context, as well as for a lithic assemblage based on the production of large unipolar flakes. We observed in the correlations between the position of artifacts, geomorphical and pedological data, OSL and Carbone-14 dates at archaeological levels, elements that allow us to discuss considering BES II as an archaeological site to integrate the interval of the Pleistocene-Holocene transition and to had interfaces with the geomorphological and environmental changes of such time. The archaeological implications of the issue and the fact that only one dating of photoluminescence has been reported from the deepest level of the site (basal gravel layer) emphasize the need for new, denser and more diversified studies.

Spatial-Temporal Changes of Soil Respiration across China and the Response to Land Cover and Climate Change

Soil respiration (Rs) plays an important role in the carbon budget of terrestrial ecosystems. Quantifying the spatial and temporal variations in Rs in China at the regional scale helps improve our understanding of the variations in terrestrial carbon budgets that occur in response to global climate and environmental changes and potential future control measures. In this study, we used a regional-scale geostatistical model that incorporates gridded meteorological and pedologic data to evaluate the spatial Rs variations in China from 2000 to 2013. We analysed the relationship between Rs and environmental factors, and suggest management strategies that may help to keep the terrestrial carbon balance. The simulated results demonstrate that the mean annual Rs value over these 14 years was 422 g/m2/year, and the corresponding total amount was 4.01 Pg C/year. The Rs estimation displayed a clear spatial pattern and a slightly increasing trend. Further analysis also indicated that high Rs values may occur in areas that show a greater degree of synchronicity in the timing of their optimal temperature and moisture conditions. Moreover, cultivated vegetation exhibits higher Rs values than native vegetation. Finally, we suggest that specific conservation efforts should be focused on ecologically sensitive areas where the Rs values increase significantly.