Effects of early post-fire moss biocrusts on soil abiotic and biotic properties in a Mediterranean forest

After wildfires in Mediterranean forests, mosses have been described as faster colonizers in early successional stages when soil surface is more vulnerable and exposed to rainfall events. Soil erosion mitigation is an ecosystem service of high relevance provided by moss-dominated biocrusts, but information about additional functional roles of early post-fire colonization of mosses is still limited. In August 2018, a wildfire in &#8220;Sierra de Beneixama&#8221; (E Spain) affecting a total of 862 ha was followed by salvage logging management that triggered rill formation and soil erosion processes. Six months after the fire and subsequent management disturbances, the presence of mosses covering the soil reached 30%, appearing where no soil water repellency was detected. The aim of the study was to assess the short-term effects of mosses on the nutrients content and the stability of soils underlying the crust (2.5 cm depth), as well as the soil microorganisms and functions they deliver as key elements in soil recovery. Our results showed a strong decrease in the available phosphorous content in soils under the crust, suggesting consumption of this element released from the fire to moss development. In the same way, a slight decrease in soil organic carbon and nitrogen content was detected in soils beneath the biocrust. The labile fraction of organic carbon released by the fire may provide the substrate for heterotrophic soil microbes living beneath the biocrust, but while a beginning recovery of microbial biomass under mosses was observed, no higher microbial activity was detected six months after the fire. No greater differences in the microbial functionality, measured by enzymatic activities involved in carbon, nitrogen, and phosphorus cycles, were observed in soils associated with the crust. However, the response of the microbial parameters was mainly influenced by the nitrogen and phosphorous content of soils, highly released in post-fire environments. The lower developmental stage of the biocrust and the short-time since the disturbance might be an important factor in the functional recovery of the microbial community associated. Since wildfires are predicted to increase in frequency and severity due to climate change, monitoring biocrust impact on ecological functions recovery is essential to understand ecosystem resistance and resilience to future disturbances.&#160;This work was supported by funding by the &#8220;POSTFIRE_CARE&#8221; project of the Spanish Research Agency (AIE) and the European Union through European Funding for Regional Development (FEDER) [Ref.: CGL2016-75178-C2-1-R], and the Spanish Ministry of Economy and Competitiveness [grant FPI-MINECO BES-2017-081283 supporting M.G-C].

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Use of Air-Based Photogrammetry for Soil Erosion Assessment

Proceedings ◽

10.3390/proceedings2019030005 ◽

2019 ◽

Vol 30 (1) ◽

pp. 5

Author(s):

Marx L. N. Silva ◽

Bernardo M. Cândido ◽

John N. Quinton ◽

Michael R. James

Keyword(s):

Soil Erosion ◽

Mass Movement ◽

Soil Surface ◽

Point Clouds ◽

Water Erosion ◽

Mitigation Strategies ◽

Erosion Processes ◽

Relative Contribution ◽

Erosion Mitigation ◽

Soil Erosion Assessment

Water erosion affects all types of soils around the world at different intensities. However, in the tropics, water-based processes are the most important of the erosion processes and have received much attention in the last decades. Understanding and quantifying the processes involved in each type of water erosion (sheet, rill and gully erosion) is key to developing and managing soil conservation and erosion mitigation strategies. This study aims to investigate the efficiency of unmanned aerial vehicle (UAV) structure-from-motion (SfM) photogrammetry for soil erosion assessment, as well as to address some gaps in our understanding of the evolution of erosive processes. For the first time, we used a UAV-SfM technique to evaluate the relative contribution of different types of erosion (sheet, rill and gully sidewall) in gully development. This was possible due to the millimetric level of precision of the point clouds produced, which allowed us to evaluate the contribution of laminar erosion as a new component to gullies studies. As a result, it was possible to quantify sediment volumes stored in the channels and lost from the gully system, as well as to determine the main sediment sources. The UAV-SfM proved to be effective for detailed gully monitoring, with the results suggesting that the main source of sediments in the gully was mass movement, followed by rills and sheet erosion. Our findings support the use of UAV-based photogrammetry as a sufficiently precise tool for detecting soil surface change, which can be used to assess water erosion in its various forms. In addition, UAV-SfM has proven to be a very useful technique for monitoring soil erosion over time, especially in hard-to-reach areas.

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The relationship between sediment and water quality, and riverine sediment loads in the wave-dominated estuaries of south-west Western Australia

Marine and Freshwater Research ◽

10.1071/mf04044 ◽

2004 ◽

Vol 55 (6) ◽

pp. 581 ◽

Cited By ~ 8

Author(s):

L. C. Radke ◽

I. P. Prosser ◽

M. Robb ◽

B. Brooke ◽

D. Fredericks ◽

...

Keyword(s):

Water Quality ◽

Organic Matter ◽

Soil Erosion ◽

Organic Carbon ◽

Water Column ◽

Nitrogen And Phosphorus ◽

Weathering Index ◽

Sediment Loads ◽

The Impact ◽

Column Total

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m−2 year−1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter δ13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

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Can the models keep up with the data? Possibilities of soil and soil surface assessment techniques in the context of process based soil erosion models – A Review

10.5194/soil-2021-85 ◽

2021 ◽

Author(s):

Lea Epple ◽

Andreas Kaiser ◽

Marcus Schindewolf ◽

Anette Eltner

Keyword(s):

Soil Erosion ◽

Soil Surface ◽

Extreme Weather Events ◽

Erosion Processes ◽

Process Understanding ◽

Erosion Models ◽

Erosion Modelling ◽

Assessment Techniques ◽

Temporal And Spatial ◽

Further Development

Abstract. Climate change, accompanied by intensified extreme weather events, results in changes in intensity, frequency and magnitude of soil erosion. These unclear future developments make adaption and improvement of soil erosion modelling approaches all the more important. Hypothesizing that models cannot keep up with the data, this review gives an overview of 44 process based soil erosion models, their strengths and weaknesses and discusses their potential for further development with respect to new and improved soil and soil erosion assessment techniques. We found valuable tools in areas, as remote sensing, tracing or machine learning, to gain temporal and spatial distributed high resolution parameterization and process descriptions which could lead to a more holistic modelling approach. Most process based models are so far not capable to implement cross-scale erosional processes or profit from the available resolution on a temporal and spatial scale. We conclude that models need further development regarding their process understanding, adaptability in respect to scale as well as their parameterization and calibration. The challenge is the development of models which are able to simulate soil erosion processes as close to reality as possible, as user-friendly as possible and as complex as it needs to be.

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Estimating Non-Sustainable Soil Erosion Rates in the Tierra de Barros Vineyards (Extremadura, Spain) Using an ISUM Update

Applied Sciences ◽

10.3390/app9163317 ◽

2019 ◽

Vol 9 (16) ◽

pp. 3317 ◽

Cited By ~ 2

Author(s):

Jesús Rodrigo-Comino ◽

Jesús Barrena-González ◽

Manuel Pulido-Fernández ◽

Artemi Cerdá

Keyword(s):

Soil Erosion ◽

Spatial Variability ◽

Management System ◽

Soil Management ◽

Soil Surface ◽

Surface Level ◽

Erosion Rates ◽

Erosion Processes ◽

Sampling Points ◽

Soil Erosion Rates

Monitoring soil erosion processes and measuring soil and water yields allow supplying key information to achieve land degradation neutrality challenges. Vineyards are one of the most affected agricultural territories by soil erosion due to human and natural factors. However, the spatial variability of soil erosion, the number of sampling points, and plot size necessary to estimate accurate soil erosion rates remains unclear. In this research, we determine how many inter-rows should be surveyed to estimate the soil mobilization rates in the viticulture area of Tierra de Barros (Extremadura, SW Spain) using the Improved Stock Unearthing Method (ISUM). This method uses the graft union of the vines as a passive biomarker of the soil surface level changes since the time of plantation and inter-row measures. ISUM was applied to three inter-row and four rows of vines (5904 sampling points) in order to determine how many surfaces and transects must be surveyed as all the previous surveys were done with only one inter-row. The results showed average values of soil depletion reaching −11.4, −11.8, and −11.5 cm for the inter-rows 1, 2, and 3, respectively. The current soil surface level descended 11.6 cm in 20 years. The inter-rows 1, 2, and 3 with a total area of 302.4 m2 each one (2016 points) recorded 71.4, 70.8, and 74.0 Mg ha−1 yr−1, respectively. With the maximum number of sampling points (5904), 71.2 Mg ha−1 yr−1 were obtained. The spatial variability of the soil erosion was shown to be very small, with no statistically significant differences among inter-rows. This could be due to the effect of the soil profile homogenization as a consequence of the intense tillage. This research shows the potential predictability of ISUM in order to give an overall overview of the soil erosion process for vineyards that follow the same soil management system. We conclude that measuring one inter-row is enough to get an overview of soil erosion processes in vineyards when the vines are under the same intense tillage management and topographical conditions. Moreover, we demonstrated the high erosion rates in a vineyard within the viticultural region of the Tierra de Barros, which could be representative for similar vineyards with similar topographical conditions, soil properties, and a possible non-sustainable soil management system.

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Soil attributes related to water repellency and the utility of soil survey for predicting its occurrence

Soil Research ◽

10.1071/sr9941109 ◽

1994 ◽

Vol 32 (5) ◽

pp. 1109 ◽

Cited By ~ 64

Author(s):

RJ Harper ◽

RJ Gilkes

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Water Drop ◽

Organic Matter Content ◽

Clay Content ◽

Soil Surface ◽

Water Repellency ◽

Soil Survey ◽

Organic Carbon Content ◽

Penetration Time

The incidence and severity of water repellency was related to five soil class (FC I-V), based on the field texture and dry consistence of the soil surface horizons, derived from a soil survey near Jerramungup, Western Australia. Water repellency was most severe on the FC I soils (median clay content 1.5%), with 66% of samples having water repellency based on the water drop penetration time (WDPT) test >10 s. Corresponding values for the FC II and III soils (2.5%, 4.0% clay) were 37% and 20%. Water repellency did not occur on the most clayey FC IV (8.1% clay) and FC V (22.1% clay) soils. Following stratification of Ap horizon soils by 1% increments of clay content, highly significant linear relationships occurred between log [water drop penetration time (WDPT)] and log [organic carbon (OC)] for the 1-2, 2-3 and 3-4% clay classes, these respectively explaining 50, 35 and 37% of the variation in water repellency. The role of organic carbon in promoting water repellency decreases markedly with increasing clay content, with WDPT being proportional to OC4.5, OC3.9 and OC3.0 for each of these clay classes. A multivariate relationship using measures of amorphous iron, clay and organic matter explained 63% of the variation in water repellency, and this multivariate dependency provides an explanation of the poor bivariate relationships between either clay or organic carbon content and water repellency reported in previous studies. There is a strong geomorphic control of the clay content in the soil surface horizons. Given the effect that clay content has on water repellency, the susceptibility of soils to water repellency can be mapped across farms, with the actual expression of water repellency depending on soil organic matter content, and hence land use. Such discrimination will allow the prediction of water erosion hazard and identify soils requiring ameliorative treatments.

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Vegetation Restoration Alleviated the Soil Surface Organic Carbon Redistribution in the Hillslope Scale on the Loess Plateau, China

Frontiers in Environmental Science ◽

10.3389/fenvs.2020.614761 ◽

2021 ◽

Vol 8 ◽

Author(s):

Yipeng Liang ◽

Xiang Li ◽

Tonggang Zha ◽

Xiaoxia Zhang

Keyword(s):

Spatial Distribution ◽

Soil Erosion ◽

Organic Carbon ◽

Loess Plateau ◽

Effective Means ◽

Soil Surface ◽

Vegetation Restoration ◽

The Loess Plateau ◽

Loess Slope ◽

Carbon Redistribution

The redistribution of soil organic carbon (SOC) in response to soil erosion along the loess slope, China, plays an important role in understanding the mechanisms that underlie SOC’s spatial distribution and turnover. Consequently, SOC redistribution is key to understanding the global carbon cycle. Vegetation restoration has been identified as an effective method to alleviate soil erosion on the Loess Plateau; however, little research has addressed vegetation restoration’s effect on the SOC redistribution processes, particularly SOC’s spatial distribution and stability. This study quantified the SOC stock and pool distribution on slopes along geomorphic gradients in naturally regenerating forests (NF) and an artificial black locust plantation (BP) and used a corn field as a control (CK). The following results were obtained: 1) vegetation restoration, particularly NF, slowed the migration of SOC and reduced the heterogeneity of its distribution effectively. The topsoil SOC ratios of the sedimentary area to the stable area were 109%, 143%, and 210% for NF, BP, and CK, respectively; 2) during migration, vegetation restoration decreased the loss of labile organic carbon by alleviating the loss of dissolved organic carbon (DOC) and easily oxidized organic carbon (EOC). The DOC/SOC in the BP and NF increased significantly and was 13.14 and 17.57 times higher, respectively, than that in the CK (p < 0.05), while the EOC/SOC in the BP and NF was slightly higher than that in the CK. A relevant schematic diagram of SOC cycle patterns and redistribution along the loess slope was drawn under vegetation restoration. The results suggest that vegetation restoration in the loess slope, NF in particular, is an effective means to alleviate the redistribution and spatial heterogeneity of SOC and reduce soil erosion.

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Affectability of splash erosion by polyacrylamide application and rainfall intensity

Soil and Water Research ◽

10.17221/45/2011-swr ◽

2012 ◽

Vol 7 (No. 4) ◽

pp. 159-165 ◽

Cited By ~ 1

Author(s):

M. Boroghani ◽

F. Hayavi ◽

H. Noor

Keyword(s):

Soil Erosion ◽

Erosion Control ◽

Soil Surface ◽

Control Treatment ◽

Maximum Effect ◽

Soil Particles ◽

Splash Erosion ◽

Erosion Processes ◽

Significant Difference ◽

Rain Drops

Splash erosion is recognized as the first stage in a soil erosion process and results from the soil surface bombing by rain drops. At the moment when rain drops conflict with the soil surface, soil particles move and destruct the soil structure. Soil particles dispersed by rain drops and moved by runoff are two basic soil erosion processes. In this study, the effect of applying various amounts of polyacrylamide (PAM) (0, 0.2, 0.4 and 0.6 g/m2) on the quantity of splash erosion at three rainfall intensities of 65, 95 and 120 mm/h by using of FEL3 rainfall simulator was investigated in marly soil in a laboratory. Results indicated differences in the effects of various treatments with PAM at all rainfall intensities, such as 0.6 g/m2 PAM had the maximum effect on the splash erosion control by reducing soil erosion by about 28.93%. But statistical results showed that the use of various amounts of PAM (0.2, 0.4 and 0.6 g/m2) for controlling splash erosion at various rain intensities to decrease splash erosion did not reveal a statistically significant difference. Therefore, the application of 0.2, 0.4 and 0.6 g/m2 PAM reduced the splash erosion, however, there was no statistical difference among these application rates of PAM. Finally, the results of statistical analysis of different intensities showed that only at 120 mm/h there was a significant difference between PAM treatment and control treatment (0 g/m2 PAM) in the splash erosion control. At this intensity, the treatment with 0.4 g/m2 PAM produced a maximum effect on the splash erosion control with 40% in comparison with the control treatment.

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Lateral transport of SOC induced by water erosion in a Spanish agroecosystem

10.5194/egusphere-egu2020-17676 ◽

2020 ◽

Author(s):

Leticia Gaspar ◽

Lionel Mabit ◽

Ivan Lizaga ◽

Ana Navas

Keyword(s):

Land Use ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Water Erosion ◽

Land Uses ◽

Lateral Movement ◽

Erosion Processes ◽

Depositional Processes

The main route for the lateral movement of soil organic carbon (SOC) is water erosion. Awareness of the distribution and magnitude of land carbon mobilization is important both for improving models of the carbon cycle and for management practices aimed to preserve carbon stocks and enhance carbon sinks. There is a need to consider the global significance of soil erosion from soil organic carbon cycling schemes and for this reason, the movement of SOC during erosion processes should be elucidated.Our study aims to estimate the SOC redistribution induced by water erosion during a 40 years period in an agroforestry mountain ecosystem located in northern Spain. To this purpose, topographically driven transects were selected with mixed land uses to i) assess what factors modify the runoff patterns with impact on soil and carbon redistribution and ii) evaluate the mobilization of topsoil organic carbon along the transects.The lateral movement of SOC shows similar spatial patterns with that of soil erosion. To identify whether erosional or depositional processes have been predominant in the sampling sites we used 137Cs inventories and the characterization of terrain attributes of the study with a detailed analysis of the main runoff pathways. Results indicate that SOC losses were related to an increase in water flow accumulation, while the highest SOC gains were recorded at concave positions. Soil erosion processes and the content of SOC in soils are the two main factors controlling carbon budgets. The topographical and geomorphological characteristics of the transects, the spatial distribution of land uses and the presence of landscape linear elements such as terraces or paths, affect runoff and determine the sediment connectivity and carbon dynamics along the slopes.The interactions between topography and land use produce significant positive or negative effects on SOC accumulation, particularly in areas with complex topography, as the results obtained in our study sustain. Even though the effect of topography and land use/land cover and their interactions on the horizontal distributions of carbon remains largely unknown, our approach contributes to better understand the pattern of gains and losses of soil organic and inorganic carbon induced by water erosion.

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Vegetation restoration alleviated the soil surface organic carbon redistribution in the hillslope scale on the Loess Plateau, China

10.5194/egusphere-egu21-5994 ◽

2021 ◽

Author(s):

Yipeng Liang ◽

Tonggang Zha ◽

Xiang Li ◽

Xiaoxia Zhang

Keyword(s):

Spatial Distribution ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Loess Plateau ◽

Soil Surface ◽

Vegetation Restoration ◽

The Loess Plateau ◽

Loess Slope ◽

Carbon Redistribution

ABSTRACT&#160;Redistribution of soil organic carbon (SOC) in response to soil erosion along slopes plays an important role in understanding the mechanisms of SOC&#8217;s spatial distribution and turnover. Consequently, SOC redistribution has been considered in many&#160;conceptual&#160;or mathematical models of soil carbon stability and storage.&#160;Vegetation restoration has been identified as an effective method to alleviate soil erosion on the Loess Plateau, however, little research has addressed vegetation restoration&#8217;s effect on the SOC redistribution processes, particularly SOC&#8217;s spatial distribution and stability. This study quantified the SOC stock and pool distribution on slopes along geomorphic gradients in naturally regenerating forests (NF) and an artificial black locust plantation (BP), and used a corn field as a control (CK). The following results were as follows: (1) Vegetation restoration, particularly NF, slowed the migration of SOC and reduced the heterogeneity of its distribution effectively. The topsoil SOC ratios of the sedimentary area to the stable area were 109%, 143%, and 210% for NF, the BP and CK, respectively; (2) Vegetation restoration decreased the loss of labile organic carbon by alleviating the loss of dissolved organic carbon (DOC) and easily oxidized organic carbon (EOC). The DOC/SOC in the BP and NF increased significantly, and were 13.14 and 17.57 times higher, respectively, than in the CK (p < 0.05), while the EOC/SOC in the BP and NF was slightly higher than in the CK. (3) A relevant schematic diagram of SOC cycle patterns and redistribution along the Loess slope was drawn under vegetation restoration. These results suggest that vegetation restoration in the Loess slope effectively alleviated the redistribution and spatial heterogeneity of SOC through reducing soil erosion. Thus, the effects of vegetation restoration on SOC redistribution should be pay more attention in regional carbon storage estimation, especially in the Loess gully regions.Keywords: Vegetation Restoration, Soil Organic Carbon Redistribution, Loess Slope, Soil Erosion, Soil Organic Carbon Stability

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A method to detect soil carbon degradation during soil erosion

Biogeosciences ◽

10.5194/bg-6-2541-2009 ◽

2009 ◽

Vol 6 (11) ◽

pp. 2541-2547 ◽

Cited By ~ 25

Author(s):

C. Alewell ◽

M. Schaub ◽

F. Conen

Keyword(s):

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Isotope ◽

Stable Carbon Isotope ◽

Swiss Alps ◽

Wetland Soils ◽

Soil Material ◽

Process Indicator ◽

Erosion Processes

Abstract. Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools) we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri). Transects from upland (erosion source) to wetland soils (erosion sinks) of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha−1 yr−1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500–600 and 350–400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

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