Displays

Data on natural disasters shows that cities worldwide are increasingly exposed to the risk of negative consequences. Storms and floods are among the main causes of casualties and economic losses. Moreover climatic and anthropogenic changes, urbanization and other land use transformation may contribute to increase hydrogeological hazard and risk, both in mountain valleys and in floodplain areas. On the other hand well managed soil may offer many water—regulating ecosystem services. Given that the hydrological and hydraulic dynamics commonly involve a great area, which is also upstream and surrounding the city, therefore a paradigm shift both in urban and land planning is needed, in order to integrate hazard perception and risk culture in plans. This integration also requires practices of soil conservation.

Literature underlines that, in order to achieve the transition to resilient communities, it is necessary (a) to reduce soil sealing, (b) to improve the benefits of ecosystem services as part of the plan strategies, (c) to enhance the key role that landscape planning can play in environmental protection. However, in most of the current urban and spatial plans in Italy these strategic guidelines are still ignored.

In order to address these critical issues we propose a method to classify rural areas which considers both landscape and hydrological peculiarities, in order to identify, at the regional scale, the most suitable areas to plan and design the landscape. We therefore propose to identify such a kind of landscape with the definition of a “sponge land(scape)”, which aims at extending the affirmed concept of “sponge cities” to rural areas. This approach to land management may contribute to the mitigation of hydrogeological hazard and risk, by means of preserving the regulating soil ecosystem services. At the same time it will improve both the resilience level of urban areas and the ecosystems living conditions.

The method is tested in Italy, where, according to the “Report on hazard and risk indicators about landslides and floods in Italy” (ISPRA, 2018) more than ninety percent of Italian municipalities are exposed to the hydrogeological risk. The collaboration between researchers belonging to the disciplines of spatial planning (i.e. town and regional planning) and soil hydrology was considered strategic. In particular, it allows to take advantage of specialized hydrology geo-datasets into spatial planning, which are usually not taken into account. As a first step, Hydrological Soil Groups were considered in the planning procedure. Data integration in GIS made it possible to create new maps which allow priority area to emerge for ”sponge landscaping actions”, such as the adoption of Nature Based Solution or Natural Water Retention Measures. These contribute both to the mitigation of hydraulic risk and to the maximization of other complementary ecosystem services (e.g. biodiversity preservation, climate change adaptation and mitigation, erosion/sediment control).

How to cite: Pavesi, F. C., Barontini, S., and Pezzagno, M.: “Sponge land(scape)”: An interdisciplinary approach for the transition to resilient communities, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13525, https://doi.org/10.5194/egusphere-egu2020-13525, 2020.

Understanding the spatial distribution and controlling factors of soil organic carbon (SOC) at different scales is essential for an accurate estimation of soil organic carbon stocks. Furthermore, this understanding is vital for evaluating the impact of soil management on both soil quality and climate change. This study was conducted in a Loess revegetated small watershed and the effects of the topography and vegetation factors on the content and distribution of SOC at different soil depths were evaluated. Soil profiles (0-200 cm; n = 122) were sampled that represent six vegetation types (i.e., natural mixed forests, artificial mixed forests, artificial forests with a single tree species, shrubbery, and grassland) and four topographic factors (i.e., elevation, slope gradient, slope position, and slope aspect). The following results were obtained: (1) The mean SOC of the 200 cm soil profile ranged from 2.34 g kg-1 to 5.70 g kg-1, decreasing with increasing soil depth. (2) The interactions between vegetation type and topography and soil depth significantly impacted SOC (P < 0.05). Significant differences in the SOC content (P < 0.05) were also found for slope gradient, slope position, slope aspect, and elevation for 0-200cm, 0-160cm, 0-120 cm and 0-200 cm, respectively. (3) The relative contribution of topographic factors to the SOC content exceeded that of vegetation type in entire soil profile. Topography was the dominant factor controlling the spatial distribution of SOC in the studied small watershed. Therefore, topographic factors should be considered more than vegetation types for an accurate estimation of SOC storage in a revegetated small watershed. This is particularly important for the complicated topography of the loess-gully region.

How to cite: Zha, T., Yu, H., Zhang, X., and yu, Y.: Spatial distribution of soil organic carbon may be predominantly regulated by topography in a small revegetated watershed, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2376, https://doi.org/10.5194/egusphere-egu2020-2376, 2020.

Carbon storage is as a key function of soils, and several studies underpinned its capacity as a critical ecosystem service to contribute mitigating climate changes. Scientists have focused on estimating soil organic carbon stock (SOCs, in kg C/ha), associated with the services regulation of carbon sequestration. SOCs relies on estimates of SOC concentration (SOCc, in g/kg), bulk density (BD) and coarse fragment content (CRF) of the target soil depth. SOCc is usually measured with precision in elemental analysers; however, BD and CRF are often missing. In the available databases, CRF is frequently estimated visually or even ignored (being the greatest uncertainty in SOCs estimates). The general absence of these parameters leads to unrealistic predictions with systematic errors propagation in the calculation of the SOCs. Therefore, the accuracy of its prediction will depend on the availability and quality of the data as well as the calculation approaches. The aim of this study was to evaluate the accuracy of SOCs and SOCc predictions on different available soil mapping products and analyse their uncertainty.

A Mediterranean area was selected in southern Iberia Peninsula (The Region of Murcia) being particularly vulnerable to global environmental change and land degradation. We evaluate six available soil carbon products including global, European, national and local SOC estimates. We compare descriptive statistics and exploratory data analysis tool (such as boxplot and Tukey test at 95% confidence interval) for SOCs and SOCc, respectively. An external local database (255 soil profiles) was used to perform independent validation, using the R² and RMSE as information criteria. For this validation, the SOCs was calculated in each horizon of the local database using SOCc, BD and CRF data. The gaps in BD were estimated throughout pedo-transfer function locally adapted. We convert each soil profile of this database to a 0-30 cm standard depth. This standardization was carried out using the equal-area spline. Subsequently, we generated a local map of SOCs and SOCc, and their associated uncertainties, based on tree-based machine learning. To generate the map the point values of SOCc and SOCs were spatially predicted using soil environmental covariates.

The results showed a high diversity of estimates among stock maps ranging from 73,364 GgC to 27,763 GgC, and the Tukey test depicted significant differences among all cases, not being the case for SOCc estimation. The external validation revealed a poorer fit in the carbon stock (R²= 0.03 and RMSE= 22.82) than the carbon concentration, with the best-fit values of R²= 0.53 and RMSE=14.74. Furthermore, all the SOCs products showed overestimated values ranging from 44% to 164% over the estimates of generated maps.

Despite the global interest of a detailed and quantitative information of carbon stock, the poor quality of their parameters can leads to inaccuracy and overestimation prediction. It is due to a high propagation of parameter uncertainty, hence it is essential the uncertainty assessment in SOCS modelling to evaluate the soil carbon sequestration services.

How to cite: Durante, P., Guevara, M., Vargas, R., Algeet, N., and Oyonarte, C.: Uncertainties in estimating the soil carbon sequestration service, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18408, https://doi.org/10.5194/egusphere-egu2020-18408, 2020.

The soil loss tolerance (T value) is the ultimate criterion for determining whether a soil has potential erosion risks. While the existing T value criteria are mainly on national scale, and lack of consideration of the differences in soil erosion, soil properties and soil productivity between different types of land use. We calculated the global T value by using the productivity index method. The global T values ranged from 0.84 to 4.99 Mg ha^-1 yr^-1, with an average of 1.49 Mg ha^-1 yr^-1. The distribution of T values in global scale demonstrated significant spatial differences, and the range of T values in most regions of the land (98.23%) was between 1.0 and 2.0 Mg ha^-1 yr^-1. The mean T values varied from c ontinent to continent, with Africa and Oceania having higher mean T values than other continents. The T values between different land use types varied widely, and the T values of five land use types were as follows: cropland (1.67 Mg ha^-1 yr^-1) > shrubland (1.61 Mg ha^-1 yr^-1) > grassland (1.59 Mg ha^-1 yr^-1) > forestland (1.38 Mg ha^-1 yr^-1) > wetland (1.28 Mg ha^-1 yr^-1).

How to cite: Jia, L. and Zhao, W.: Assessment of the spatial distribution of global soil loss tolerance by using the productivity index method, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4538, https://doi.org/10.5194/egusphere-egu2020-4538, 2020.

Soil conservation is one of the most important ecosystem services, as it has a positive impact on soil fertility and land productivity. Soil conservation has multiple facets, while the current research on soil conservation has rarely considered combining the soil displacement conservation ability and river sediment transport conservation. On the basis of the Revised Universal Soil Loss Equation (RUSLE) and the Sediment Delivery Ratio (SDR) module of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), this study developed an indicator, named soil conservation risk, by introducing the soil displacement risk and the river sediment transport risk. The natural growth scenario and reforestation scenario of land use change in the Nile River Basin from 2010 to 2100 were estimated as the input parameters. Three main results were obtained. (1) From 2000 to 2010, the grassland increased by 4.34%, and the forest decreased by 4.91%. (2) From 2000 to 2100, the soil conservation presents a declining tendency in the two scenarios, and the soil conservation amounts based on soil displacement conservation and river sediment transport conservation were 1550.48±177.12 and 100.93±6.24 (t ha^-1 y^-1) in a natural growth scenario, respectively, and 1576.78±63.21 and 104.41±0.30 (t ha^-1 y^-1) in a reforestation scenario, respectively. (3) We compared the soil displacement risk and river sediment transport risk, and the reforestation scenario can effectively relieve the soil displacement risk in the first fifty years, while the river sediment transport risk can be relieved from 2010 to 2100. Overall, when reducing the conversion rate of the forest by 0.5 times and increasing the rate of conversion to forest by 0.5 times, the effect of land use changes to the river sediment transport risk has a longer-term effect than do changes to the soil displacement risk.

How to cite: Liu, Y. and Liu, H.: Soil conservation risk assessment based on land use scenarios in the Nile River Basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2513, https://doi.org/10.5194/egusphere-egu2020-2513, 2020.

Abstract: A comprehensive study on the dynamics of ecosystem services and their driving factors is the key prerequisite for enhancing local ecological sustainability. Based on relevant sets of big data, including spatial land data, soil data, DEM, climatic data and social-economic data, using InVEST model and multivariate logistic regression model, the study firstly assessed the spatiotemporal variation of ecosystem services for China’s Beijing-Tianjin-Hebei (Jing-Jin-Ji) region from 1990 to 2015. The study then analyzed the natural and socioeconomic factors affecting the ecosystem services. The results show that large spatial and quantitative differences exist in the supply of multiple ecosystem services, and the changes of different types of ecosystem services are driven by different factors. For water yield, the areas of arable land, wetland and built-up land and precipitation are the most influential factors; The areas of arable land, precipitation, temperature, altitude, urbanization rate and amount of nutrient applied per unit area are determinants of changes in nutrient retention; The areas of grassland and forest, temperature, altitude, GDP per capita and urbanization rate affect the soil retention to great extent; for carbon storage, its key influential factors are the areas of different land use types and urbanization rate. The study can facilitate identification of where and how to enhance multiple ecosystem services.

Keywords: dynamics of ecosystem services, driving factors, InVEST, multivariate logistic regression model

How to cite: Li, S., Lei, G., and Yu, X.: Dynamics of ecosystem services and their driving factors in China’s Beijing-Tianjin-Hebei regional development, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8235, https://doi.org/10.5194/egusphere-egu2020-8235, 2020.

Among all pollutants, copper (Cu) is of major environmental and toxicological concern with contamination from various origins. Moreover as a cation, Cu is easily complexed by the negatively charged soil organic matter (OM) inducing high concentrations in upper layers of soils where OM dominates. Due to its biotic and abiotic interactions with soil constituents Cu is expected to affect several soil processes among them the soil respiration, but studies provided contrasting results as soil respiration have been shown to decrease or increase with soil contamination depending on the studies.

In this study, we aimed at assessing how soil respiration is affected by Cu contamination in order to quantifying as a first approach the GHG emissions for a contaminated soil. We performed a quantitative review of literature focusing on soil heterotrophic respiration (thus excluding autotrophic respiration from plants) which aimed at 1) assessing the impact of a copper contamination on soil carbon (C) mineralisation and thus CO₂ emissions, and 2) hierarchizing the determinants of such an impact on C mineralisation compare to the influence of pedo-climatic soil parameters such as pH, clay percentage or the type of climate.

On the basis of a selection of roughly 390 literature data, global main results showed a decrease in soil CO₂ emission with an increase in soil Cu contamination. Data from ex situ spiking experiments could be easily differentiated from the ones originated from in situ natural contamination due to their sharper decrease in soil organic carbon mineralisation. Interestingly, ex situ spikes data on the short term provided a threshold: an increase in soil CO₂ emissions was noticed for data below total soil Cu content of 180 mg kg^-1 while a decrease was observed above this concentration. On the contrary, long-term in situ contamination due to anthropogenic activities (urbanisation, agriculture …) did not significantly impact soil carbon mineralisation except when we focused on the high inputs of industrial contamination (smelter, composted plant…). Soil pH was found as a variable of interest as acidic soils were more sensitive to Cu contamination for C mineralisation than neutral or alkaline soils, while the % of clay and the type of climate did not add explanation to the variation in C mineralisation. These results are discussed and the collected data allowed us to propose a general equation quantifying how soil respiration can be affected by a Cu contamination.

How to cite: Laura, S., Bertrand, G., Olivier, C., and Isabelle, L.: Soil copper contamination effect on carbon mineralisation: evidence of a soil CO2 emission decrease from literature review, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2201, https://doi.org/10.5194/egusphere-egu2020-2201, 2020.

Human interactions with Earth systems have accelerated dramatically in recent decades. Human activities are altering the Earth system and exerting significant impacts on the environment, and undermining improvements in human wellbeing and poverty alleviation. In order to secure global prosperity and transform to global sustainability, United Nations launched the 17 Sustainable Development Goals (SDGs) of the 2030 Agenda for Sustainable Development in 2015. The goals include efforts to eradicate extreme poverty and to consolidate efforts to slow climate change and preserve our world environment. The process of implementing the SDGs has created new challenges for policy makers and for the scientific community. Half of the Sustainable Development Goals are related to environment and natural resources. Geographical Science is one of the most important KEY for sustainable development. Geographers have been conducting various experiments and modelling at multi-scales, and tried to identify the relationships between human activities and various earth surface processes, dwell on ecosystem processes and ecosystem services trade off at multi-scale, model the effects of human activity and earth systems, and try to figure out the possible sustainable solutions for regional, national and global developments. It’s time to launch a new journal focus on Geography and Sustainability for the world. That’s why, Faculty of Geographical Science (Beijing Normal University) start to publish the new journal: Geography and Sustainability. The new journal focus on: Geographical processes, Human-Environmental Systems, Ecosystem services and human being, Sustainable development, Geo-data and model for Sustainability. The new journal is also the office journal for IGU Commission on Geography for Future Earth: Coupled Human-Earth Systems for Sustainability.

How to cite: Zhao, W., Fu, B., and Liu, Y.: How to promote Geography for Sustainability, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-130, https://doi.org/10.5194/egusphere-egu2020-130, 2020.

Soil formation is vital for the existence of life. Soil provides a wide range of direct and indirect ecosystem services (ES) such as carbon sequestration, water and flood regulation, food provisioning, raw material culture, and heritage. Soil formation is complex and depends on the parent material, climate, topography, biological activity, and time. This intricate process is strongly affected by human activities (e.g., agriculture, urbanization) that generally result in a degradation process. Mapping soil formation is challenging due to a large number of variables involved and the complexity of their interaction. The objective of this work is to map soil formation in Lithuania. Several variables were selected to assess soil formation such as lithology, time (glacial retreat), slope, topographic wetness index, roughness, slope length, soil mineralogy, depth, texture, available water capacity, pH, organic carbon, nitrogen, potassium, phosphorous, January average temperature, June average temperature, annual average precipitation, and land use. To validate the model, we used soil cation exchange capacity. The variables were ranked according to the least to the most favorable conditions. The weight of the variables was assessed using the Analytic Hierarchical Process and ranked by 20 international experts on the soil. The results of the model are acceptable (r²=0.48), owing to the complexity involved in soil formation.

This work was funded from the European Social Fund project LINESAM No. 09.3.3-LMT-K-712-01-0104 under grant agreement with the Research Council of Lithuania (LMTLT).

How to cite: Pereira, P., Brevik, E., Inacio, M., Kalinauskas, M., Miksa, K., and Gomes, E.: Mapping soil formation in Lithuania. A national-scale analysis., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3925, https://doi.org/10.5194/egusphere-egu2020-3925, 2020.

Alpine deserts are noteworthy habitats in high mountain systems such as the Caucasus. However, very little is known on the soil properties in these habitats. Another unexplored question is the transition between subnival (lower part of alpine desert) and nival (upper part of alpine desert) belts. We studied soils and vegetation in an alpine desert along its practically entire elevation range (3000-4000 m a.s.l.) on two contrasting slope aspects (north vs south) of Mt. Kazbegi, the Central Great Caucasus, Georgia. Vegetation with standardized stratified-random design and collected soil samples for measuring pH, soil organic content (SOM) and available nutrients (N, P, K) were sampled; the collected data were analyzed with direct gradient methods as well as multivariate ordination. 63 species were recorded and, as expected, strong dependence of species distribution on elevation and between slopes was documented. We found that soil pH increased monotonically with altitude on both N and S slopes and reached alkaline values with bare bedrock. The changes were steeper on the northern slope than on the southern slope, and, remarkably, many relatively abundant species changed their preference to slope aspect from N to S in parallel with the increasing difference in soil pH.  We suspect that the pH  observed shift in slope preference, at least in part, can be explained by the effect of different soil pH. As for SOM, it decreased from very low values to zero at the higher altitudes, whilst available nutrients dropped dramatically and predominantly multispecific vegetation patches characteristic for subnival belt changed abruptly to monospecific patches or solitary plants typical for nival belt. These abrupt changes occurred at 3400-3500m a.s.l., and most probably indicate a vegetation switch between the mentioned belts on Mt. Kazbegi.

Overall, our results show two characteristics of alpine desert vegetation and soils, which have not been documented to date: (1) an unexpected change of slope preference of many relatively abundance plants which probably is associated with different soil pH profiles on N and S slopes, and (2) a vegetation switch between subnival and nival belts that occurs at relatively lower elevations than expected from the concept of alpine-nival ecotone.

How to cite: Jolokhava, T. and Kikvidze, Z.: Altitudinal soil and vegetation transitions in alpine desert, the Central Great Caucasus, Georgia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-421, https://doi.org/10.5194/egusphere-egu2020-421, 2020.

Fire is an essential element of the environment and a vital force for shaping landscapes all around the world. It has a critical role as driver of natural ecosystem processes and many plant communities are fire dependent aros the globe. However, although fire is a natural and regular component of some biomes in the Earth’s systems, it can become a destructive force when natural ecosystems are disturbed, fire is introduced at a rate not previously experienced, and recovery to a pre-fire state is not possible. Thus, assesing the potentially harmful environmental impacts of fire and building the underlying knowledge required to successfully manage fire makes are crucial in order to understand the role of fire in all its different dimensions. Over the past year, fires in California in the United States and in the Amazon rainforest in Brazil have grabbed the world’s attention. The increased rates of fire events in some of these areas, mostly attributed to land degradation processes, have led to international concern. More recently, several bushfires all around Australia have had dramatic impacts in the environment with 10 million hectares burned so far, including large portions of the natural environment. These unprecedented fires are predicted to affect to a large extent the soil characteristics, processes and function in several ecosystems. In this presentation, we highlight some of the most recent research published during the last year on the effects of fire on soil functions and the provision of soil ecosystem services. We also showcase some of the possible approaches to protect and conserve soil ecosystems affected by extreme fires and propose available strategies for post-fire management.

How to cite: Muñoz-Rojas, M. and Pereira, P.: Fire in the environment: effects on soil functions and ecosystem services in a changing world, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11848, https://doi.org/10.5194/egusphere-egu2020-11848, 2020.

The Qinghai-Tibetan Plateau (QTP) is a “sensor” and “sensitive area” for climate change in Asia and even the northern hemisphere, and its soil ecosystem services are vital components to all aspects of life in the region and support ecosystem functions and services. Understanding the distribution of regional ecosystem services, the relationship among ecosystem services and the influencing factors is an important prerequisite for the protection and optimization of the ecosystem on the QTP. This study quantitatively analyzed the spatio-temporal distribution and interrelationship of multiple ecosystem services such as soil retention (SR) service, water yield (WY) service, habitat quality (HQ) service, crop supply (CS) and livestock supply (LS) services in the Qinghai-Tibet Plateau (QTP) based on InVEST model, statistical and NPP data. Besides, we explored the influences of temperature, elevation, population density, land use and land cover on the relationship of ecosystem services and put forward the corresponding optimization strategy based on ecosystem services perspective. We found that SR, WY and HQ decreased from the southeast to the northwest, regulating services-supporting services are mainly identified as synergies and CS-HQ and CS-LS are manifested as trade-offs. In addition, natural factors (temperature, elevation) influence the distribution of CS and the level of significance of LS, natural factors and the land-use/land-cove affect the shift in the trade-offs and synergies between regulating services and supporting services, and population density mainly affects the relationship between supporting services and other types of services. Providing that the scale effect of ecosystem service relationships in the QTP, we divided the livestock supply collaborative promotion area, the crop-livestock tradeoff optimization area and the multi-ecosystem service optimization area, then put forward specific suggestions at the city scale. This study could be a step forward to optimizing the balance between provisioning services and supporting services or regulating services in the QTP and implementing ecosystem protection policies effectively.

How to cite: Hou, Y., Zhao, W. Z., Liu, Y., and Hua, T.: What are the relationships among ecosystem services in Qinghai-Tibetan Plateau of China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-731, https://doi.org/10.5194/egusphere-egu2020-731, 2020.

Soil erosion by water is one of the most important degradation processes. Land use has important effects on soil properties, therefore it is key to identify the type of management that have more impacts and find solutions to mitigate it. In order to understand the effects of land use management on soil and soil erosion in the Istria region (Croatia), we studied the impacts of different agriculture practices (vineyard, cropland, and olive orchard) on soil properties and runoff. The simulated rainfall was carried out at 58 mm h⁻¹ in the summer of 2018 (30% soil water content) for 30 min on 0.785 m² circular plots. The results showed that bulk density was significantly higher in cropland plots than in the vineyard and olive orchard. Soil organic matter, mean weight diameter, and aggregate stability were significantly higher in olive orchard plots than in the vineyard and cropland. Runoff and sediment losses were higher in olive orchard compared to vineyard plots. Carbon, nitrogen, and phosphorus losses were highest in olive orchard plots with 3.9 kg ha^-1, 405.2 g ha^-1 and 73.6 g ha^-1, respectively, while lower values were measured in the vineyard plots, where nutrients losses were lower with 0.9 kg ha^-1, 73.8 g ha^-1 and 6.5 g ha^-1, respectively. No runoff was observed in cropland plots. Even with the highest measured values of runoff and erosion in the herbicide treated olive orchard, results indicate that both herbicide application and tillage represent a threat to the sustainability of Istrian soils. Vegetation cover on cropland reduces the runoff generation indicating the need for adoption of conservation strategies. In current management, vegetation removal should be avoided since it contributes to practice to reduce nutrient losses and increase the sustainability of the soils.

Keywords: Soil water erosion, Soil tillage, Rainfall simulation, Agriculture land management, Mediterranean

Acknowledgements

This work was supported by Croatian Science Foundation through the project "Soil erosion and degradation in Croatia" (UIP-2017-05-7834) (SEDCRO).

How to cite: Bogunovic, I., Telak, L. J., and Pereira, P.: Management-induced soil water erosion and nutrient losses in different land use in Mediterranean environment, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1151, https://doi.org/10.5194/egusphere-egu2020-1151, 2020.

Soil particles are related to vegetation growth and source of depositsc in arid and semi-arid desert. It is worth mentioning that plantation is the one the most effective ways improving desert soil conditions. The sandy land on the eastern shore of Qinghai Lake is the biggest area in the desertified land of Qinghai Lake Basin. Some measures have been taken to prevent and control desertification in Kutu district since 2008. We chose the dunes that planted Salix cheilophila、Hippophae rhamnoides、Pinus sylvestris、Populus simonii and Hedysarum scoparium as study sites, then collected deposits from topsoil to the depth of 60 cm to probe into the change of grain size features. The results show that: (1) All study dunes primarily are made up of medium materials for mean particle size (M) is medium sand widely distributed from 0.27mm to 0.31mm which are presented uniform. (2) The sorting coefficient of sediments is concentrated between 0.5 and 0.9 with better performance. The skewness value is between 0 and 1, which shows nearly symmetrical and positive skewness. The kurtosis is between wide and medium. (3) The vertical change of particle size composition at different depths of 60 cm indicates that plantation significantly changed the distribution of the surface sediments in the dunes, whereas particle compositions at different depths did not have obvious rules of different plants. (4) The vegetation recovery time in study area was short, therefore, interactions between wind sorting, terrain fluctuations and vegetation growth might affect the grain size features of surface sediments in study area.

How to cite: Tian, L., Zhang, D., and Yu, Y.: Grain size of deposits in different plantation dunes on the eastern shore of Qinghai Lake, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1746, https://doi.org/10.5194/egusphere-egu2020-1746, 2020.

Drought is the most recurrent and destructive hazard in arid and semi-arid regions, and will only become more complex under climate change. It is vital to characterize the various types of drought, to investigate the potential factors affecting different types of drought, and to assess the relationship between drought types. In this study, the Standardized Precipitation Index (SPI) and the Standardized Runoff Index (SRI) were used to characterize meteorological and hydrological drought, respectively, and used to investigate drought characteristics and mechanisms in 17 catchments on the Loess Plateau from 1961–2013. Furthermore, the propagation time from meteorological to hydrological drought was explored and the potential factors influencing drought propagation time were investigated. The results indicate that the Loess Plateau has experienced an increased tendency towards both meteorological and hydrological droughts over the period 1961−2013, with hydrological drought more serious than meteorological drought at various drought assessment time scales. Moreover, average drought duration and severity were greater for hydrological drought than meteorological drought. Maximum 5-day precipitation (Rx5day) was the dominant extreme climate index for explaining variance in meteorological drought at the annual time scale. Owing to the greater complexity underlying hydrological drought, Rx5day, the number of warm days (Tx90p), and the number of warm nights (Tn90p) all contribute to the variance in hydrological drought. Furthermore, the percentage of forested land had a significant positive association (p<0.001) with propagation time, whereas the percentage of land given over to pasture had a significant negative association (p<0.001) with propagation time.

How to cite: Wu, J. and Miao, C.: Propagation from meteorological drought to hydrological drought on the Loess Plateau, China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2913, https://doi.org/10.5194/egusphere-egu2020-2913, 2020.

Abstract:

Soil microorganisms play an important role in the material cycle, especially in the alpine region where the ecological environment is fragile. Therefore, we selected a typical soil on slop for sampling in a sub-watershed upstream of the Yellow River Basin. Microbial species were detected by High-throughput sequencing. At the same time, the relevant physical ang chemical properties of the soil were also tested, such as mechanical composition, soil type, moisture content, TN, TP, pH, organic matter et al. Species and abundance of microorganism were calculated and analyzed by significance test regression analysis. The results showed that Nitrospira and Gaiella were the main microorganism. There was no obvious relationship between soil type and microorganism species. But soil moisture content had a significant effect on diversity of microorganism. There was a significant negative correlation between Bradyrhizobium and soil TN, and a negative correlation between Nitrospira and Nocardioides species abundance. This study provides a data basis for microbiological research in alpine regions, and also actively explores the characteristics of microbial distribution.

How to cite: Wang, J., Qin, T., Liu, F., Nie, H., and Lv, Z.: Distribution and cause and cause analysis of typical soil microorganisms in alpine region, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3827, https://doi.org/10.5194/egusphere-egu2020-3827, 2020.

The plant density and spatial distribution in artificial vegetation is obviously initialized at the planting stage. Plants dynamics and spatial pattern may change over time as the result of interactions between individual plants and habitats, but whether this is the case for desert shrubs in artificial sand-fixing regions is largely unknown. Here we examined changes in plant density and distribution patterns of three shrubs (Artemisia ordosica Krasch., Caragana korshinskii Kom., and Hedysarum scoparium Fisch.) in different regions restored for 27, 32 and 50 years (R27, R32, R50), respectively. The vegetation analysis showed that A. ordosica were the dominated species across the 3 restoration regions. The density of A. ordosica and H. scoparium showed a significant increase from R27 to R32, then decreased in R50. However, there was no C. korshinskii survive in R27. The density of C. korshinskii was also low in R32 and R50. The variance-to-mean ratio (VMR) was used to characterize the spatial distribution patterns to fit the observed frequency distributions of densities of the three shrubs. A. ordosica and C. korshinskii all showed significantly clumped distribution in three restoration regions. For H. scoparium, it showed uniform distribution in R27 and R50, however showed clumped distribution in R32. We also quantified changes in soil physio-chemical properties in different restoration regions. The proportion of sand-sized particles in the topsoil was reduced sharply; the proportion of silt and clay increased greatly from 17.3 and 4.6 to 21.4 and 10.4%, respectively. N and K contents were not significant different among R27 (0.52 and 0.93 g/kg, respectively) and R32 (0.59 and 0.98 g/kg, respectively), but has significant differences with R50 (0.78 and 1.06 g/kg, respectively). P content and soil organic matter content gradually increased with successional age. The results showed that compared to C. korshinskii and H. scoparium, A. ordosica seems to be more suitable in revegetated desert areas. Pattern analysis suggested a successive replacement of C. korshinskii, which had low proportions of survived shrubs, by the dominant A. ordosica. The soil properties were also significantly improved after restoration. This study contributes to understanding of the distribution patterns of shrubs plants and their effects to soil property in revegetation projects in arid desert area.

How to cite: Liu, M.: Distribution patterns of planted-shrubs of different restoration ages in artificial sand-fixing regions and effects on soil property in the southeastern Tengger desert, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7900, https://doi.org/10.5194/egusphere-egu2020-7900, 2020.

Abstract:Rwanda is located in the plateau of the central-eastern Africa nearby the equator of the Earth, known as ’The Land of a Thousand Hills’, and covers the part of the region of the Upper Nile. The sloping lands are ubiquitous across Rwanda, and the sloping farmlands account for more than 70 per cent of the sloping land resources. The soil and water losses are very severe on the sloping lands, especially on the sloping farmlands due to the farming activities and soil water erosion induced by the erosive rainfall events. Therefore, the soil erosion and soil organic carbon (SOC) and nutrient losses and the resultant soil deterioration and crop yield decline on the sloping farmlands in this country have attracted the widespread concerns. It is necessary to understand severity of the SOC and nutrient losses on the sloping farmland due soil erosion in term of launching the countermeasure to control the losses. The investigation on the SOC and nutrient losses in the sloping farmlands and the rainfall was carried out on the runoff plot with 20m long, 5m wide and gradient of 12°in Rubona, Huye District, south province of Rwanda. The cropping rotation of soybean-maize-groundnut was practiced on the plot during the monitor on soil losses from the plot. The contents of constituents of soils lost from the plot decreased in the order: SOC> total potassium (TK)>total nitrogen (TN)>total phosphorus (TP). The loss intensities of SOC from the plot varied from 383.0 kg/hm² to 1680.9 kg/hm² in the period from 2011 to 2013, 259.4 kg/hm² to 1138.5 kg/hm² for TK, 41.2 kg/hm² to 180.8 kg/hm² for TN, 9.2 kg/hm² to 40.2 kg/hm² for TP. The loss intensities of SOC, TK, TN and TP were 1262.3 kg/hm², 99.0 kg/hm², 99.4 kg/hm², 35.4 kg/hm² in 2017, and 3786.8 kg/hm², 2970.0 kg/hm², 298.1 kg/hm² and 106.3 kg/hm² in 2018, respectively. The loss intensities of SOC and nutrients varied significantly over the years. It can be seen that the amounts of erosive rainfall have the crucial impacts on loss intensities of SOC and nutrients through analyzing the relation between loss intensities and erosive rainfall. The relations between loss intensities of SOC and nutrients and mounts of erosive rainfall can be described by exponential function. Compared with the loss intensities of SOC and nutrients on the runoff plot, the loss intensities were much less on the plots with the corresponding soil and water conservation measures such as terracing and plant hedges. Therefore, the measures of anti-erosion should be adopted on the sloping farmlands in an effort to reduce SOC and nutrient losses and keep the sustainable soil productivity in Rwanda. 

Keywords: SOC; nutrient; sloping farmland, Rwanda

How to cite: Wang, B., Li, C., and Li, Z.: Soil organic carbon and nutrients losses form the sloping land in the scenario of water erosion in the south of Rwanda, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21057, https://doi.org/10.5194/egusphere-egu2020-21057, 2020.

Re-vegetation has been widely carried out to prevent land degradation, reduce soil erosion, and improve soil quality. In order to investigate the characteristics of soil nutrients content in different land use types of karst gabin basin, soil organic matter, soil total nitrogen, soil total phosphorus, soil total potassium, soil pH, and soil texture in woodland, agricultural land, orchard, and grassland were surveyed in Mengzi Gabin Basin, Southwest of China. The difference of soil indicators between vegetation types was analyzed, and soil fertility quality of four land use types was comprehensively evaluated by the soil quality index (SQI). The results showed that land use significantly affected soil organic matter content. Soil organic matter content was the highest in grassland, followed by agricultural land and forest land, while orchard was lowest. There was a significant difference in soil total nitrogen content between different land uses. The total nitrogen content in farmland soil was the highest, followed by grassland and woodland, and the lowest in the orchard. Woodand had the highest total potassium content and the lowest total phosphorus content. The grassland soil had the highest total phosphorus content and the lowest total potassium content. pH value in the four land use types was acidic, ranged from 5.82 to 6.67. The soil quality index showed that woodland had the highest soil fertility quality. The results of the study could provide the basis of soil nutrients variation and status in Gabin basin, and also provides support for evaluating the soil improvements during vegetation restoration in fragile Karst ecosystems.

How to cite: Tang, L., Shan, Z., and Yu, Y.: Evaluation of soil quality in different land uses in the Mengzi Gabin Basin, Southwest of China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10259, https://doi.org/10.5194/egusphere-egu2020-10259, 2020.

Intensification of returning farmland to forest has led to success in ecological construction and improvement. Returning farmland to forest project has been implemented at the Three Gorges Reservoir Area (TGRA) since 2000. We aimed to access the soil conservation service variation in the Lanlingxi watershed of TGRA using land cover change as a proxy indicator. Lanlingxi watershed is a representative pilot of TGRA, which included specialized in the national demonstration of returning farmland to forest project. The multi-stage methodology included; (i) land cover analysis in phased process using and GIS (ii) assessing soil conservation service values using InVEST model. The results showed that during 1999-2017, significant land cover transformations occurred in the study area, increase of economic forests land, tea, citrus in exchange of cultivated land. Langlingxi watershed covered an area of 1527.43 hm², cultivated land occupied 32.58% of the 497.65 hm² in 1999, and reduced to 4.16% in 2017. Tea land occupied 19.41% of the total land in 2017, which was under 1% in 1999. Land cover conversion was from cultivated land to tea, citrus and bush. Land cover change happened within at lower altitude of protection and economic forest, no significant change at ecological welfare forest. The value of soil conversation was 415.08 t/hm² in 1999, while the land was cover by tea, citrus and bush in 2017, the value of soil conversation was higher than 490 t/hm². Total soil conversation increased 28.56% at lowest attitude and 19.82% at intermediate altitude area in 2017 as a result of land cover change. The ability and capacity of soil conversation were higher by returning farmland to forest. Such changes contributed to the increase of soil conservation service, mainly as a result of a better capacity in soil and water conservation by forests. The results of this study emphasized the importance of land management and forests restored for better ecosystem services and conservation.

How to cite: Huang, Y., Huang, Z., and Ma, L.: Interactions between soil conversation service and land cover changes in the Three Gorges Reservoir Area after returning farmland to forest, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7714, https://doi.org/10.5194/egusphere-egu2020-7714, 2020.

Ecosystem services (ES) are defined as material and non-material benefits that people derive directly or indirectly from nature, normally divided in provisioning, regulating and cultural. Previous works have made great progress in mapping and assessing ecosystem services (ES) that are directed toward exploring various aspects of ecological changes and economic values. These preferences, however, may neglect the important role of people who are the direct beneficiaries in this ecosystem. Therefore, including these stakeholders in ecosystem services assessment identifies their relations and perceptions between ecosystem services and society. In order to quantify and map these relations and perceptions, we designed and implemented an analytical framework based on the Public Participatory Geographic Information System (PPGIS) method to explore local stakeholders’ (Farmers, Government managers/Experts, and Company employees) similarities and differences in recognition of preferences and social values for ecosystem services in a typical Karst basin. Our results showed that remarkable differences appeared in preferences for ecosystem services across three groups. Farmers gave more preferences to provisioning services, Government managers/Experts to regulating and cultural services, and Company employees’ preferences were individualized. The spatial distributions and relations of social values for ecosystem services also showed great differentials. Provisioning services were always related to specific natural conditions, regulating services to forests, and cultural services to specific locations around tourism localities, forest, and wetland parks. The three stakeholder groups perceived more synergies than tradeoffs between the different ecosystem services. Landscape beauty was the most influential service in Farmers’ and Company employees’ perceptions, while Local climate change regulation was the most influential service in those of Government managers/Experts. The local stakeholders’ surveys can improve the enthusiasm of the local people to participate in environmental management and provide more socio-ecological information to help the managers alleviate the conflicts among different stakeholders.

How to cite: Wu, X., Zhang, W., Yu, Y., and Pereira, P.: Integrating preferences and social values for ecosystem services in local ecological management: A framework applied in Xiaojiang Basin, Southwest of China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10363, https://doi.org/10.5194/egusphere-egu2020-10363, 2020.

An accurate assessment of soil water balance components (SWBCs) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information of SWBCs is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and thus can be used to determine SWBCs from a hydrologic balance. A database of soil moisture measurements from six experimental plots with different treatments in the middle Heihe River Basin of China was used to test the potential of a soil moisture database in estimating the SWBCs. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (K_s) and soil water retention features, for supporting the SWBC estimations. Then we determined evapotranspiration and other SWBCs through a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well, and published SWBCs values at nearby sites), and the water balance equation technique to verify the estimated SWBCs values, all of which showed a good reliability of our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the SWBC estimation and any restrictions on its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1~ 867.3 mm) and deep drainages (170.7~364.7 mm). Moreover, the unmulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season because of the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the SWBCs in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.

How to cite: Liu, H., Yu, Y., Li, Z., Zhao, W., Yang, Q., Yang, R., and Liu, J.: Estimation of Soil Water Balance Components Based on Continuous Soil Moisture Measurement and Inversed Richards Method in an Irrigated Agricultural Field of a Desert Oasis, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6274, https://doi.org/10.5194/egusphere-egu2020-6274, 2020.

The soil available water content (AWC) has a strong ability to indicate the soil water conditions under different land cover types. Although the AWC has long been calculated, soil water characteristic curve estimation models and the distribution of AWC, as well as the impact factors, have rarely been evaluated in the Loess Plateau of China. In this study, four typical land cover types were selected: introduced shrubland, introduced grassland, natural restored shrubland and natural restored grassland. Four widely used models were compared with the van Genuchten (VG) model, including the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Tyler and Wheatcraft (TW) model, and linear fitting (LF) model to estimate the wilting point. The distribution of AWC and the relationships with environmental factors were measured and analyzed. The results showed the following: (1) the MV model was the most suitable model to estimate the soil water characteristic curve in the Loess Plateau; (2) the factors impacting the AWC varied under different precipitation gradients, and the area with a mean annual precipitation of 440-510 mm was the most sensitive zone to environmental and vegetation factors; and (3) the soil water deficit was more severe when considering AWC than when considering soil water content (SWC), and the water deficits were different under introduced grassland and introduced shrubland. Consequently, the construction of vegetation restoration should be more cautious and consider the trade-off between soil conservation and water conservation. During restoration, policy makers should focus on the AWC in addition to the SWC to better assess the soil moisture status.

How to cite: Zhang, X., Zhao, W., and Pereira, P.: Aggravated water deficit in the Loess Plateau of China as indicated by the soil available water content, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8619, https://doi.org/10.5194/egusphere-egu2020-8619, 2020.

How to cite: Jonczak, J., Sut-Lohmann, M., Polláková, N., Parzych, A., Šimanský, V., Donovan, S., and Medinski, T.: Comparison of bioaccumulation potential of eleven pine species in low polluted ecosystem, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8746, https://doi.org/10.5194/egusphere-egu2020-8746, 2020.

A big data system plays a significant role in various fields. This technology has also been applied to environment fields because it can discover hidden patterns between environmental factors. As the massive data set was constructed for several decades, big data analysis has widely been using for extracting useful information by analyzing different types of big data sets. In this study, we developed a big data system frame to assess the ecosystem service provided from surface soil. Among big data platforms, we used the Amazon Web Service (AWS) due to their cost-efficiency and hardware flexibility. There are five stages of the big data system (i.e. data acquisition– data storage – data processing – data analysis – visualization). In the data acquisition step, the soil sensor and Internet of Things (IoT) system were used, and we collected existing soil properties data provided by national institutes such as Rural Development Administration (RDA), Ministry of Environment (MOE), and Ministry of Land, Infrastructure, and Transport (MOLIT). AWS S3 platform, which is an object storage service and provides easy-to-use management features to users, was accepted as the data storage platform of the big data system. Amazon EMR, Amazon SageMaker, and Amazon QuickSight were used for the step of data processing, data analysis, and visualization of the big data system respectively. We tested that the developed system could predict soil bulk density and able to replace a typical environmental model by using models based on machine learning and deep learning. The results of the two tests showed positive results that the developed models could predict soil properties and simulate natural phenomena as much as the typical environmental model could.  However, since the system is at an early development stage, it needs repetitive tests in the future considering various soil properties. If this system becomes fully functional, the system will be helpful to improve soil environments.

How to cite: Lim, K. J., Lee, D., Kim, J., Yang, J. E., and Shin, M.: Development of a big data system to assess ecosystem services of surface soil , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12781, https://doi.org/10.5194/egusphere-egu2020-12781, 2020.