Soil Erosion Potential Research Articles

A new protocol for monitoring operational outcomes of environmental management in commercial forestry plantations

Environmental degradation is a global phenomenon with a high likelihood of influencing human quality of life. Effective management responses are needed to achieve societal goals of sustainability. We develop here a new monitoring protocol (Management Check: MATCH) that comprehensively evaluates management outcomes at the operational level. Using the Driver-Pressure-State-Impact-Response (DPSIR) framework, we identified pressures influencing ecosystem integrity inside conservation corridors and commercial compartments of a timber production landscape mosaic. They were 1) domestic livestock grazing (the only exogenous pressure), 2) fire management, 3) invasive alien plants (IAPs), and potential soil erosion from two sources: 4) roads, and 5) harvested timber compartments. We assessed the effects of these on wetland and stream buffers. Environmental incidents accounted for more serious management issues (e.g. oil spills). Management responses were systematically unpacked into point-form questions, which formed the building blocks of our monitoring protocol. We assessed management in twelve plantations in KwaZulu-Natal, South Africa. Answers were compared with Best Operational Practice (BOP), and reworked into a Weighted Index of Compliance (WIC) per section. We found that there was poor management of livestock grazing, but good management of IAPs, roads, and timber compartments. Management of wetland and stream buffers was very good. Fire management presented problems linked to lack of direct effects, measurable at the spatial and temporal scales of operations. We discuss operational outcomes within their respective legislative frameworks, and suggest ways of improving management operations, where needed. MATCH is the first monitoring protocol to comprehensively assess environmental management of commercial forestry at the operational level, and to clearly translate operational activities into measurable progress towards strategic goals. In doing so, MATCH breaks down silos and builds bridges for efficient environmental management in dynamic socio-ecological systems. Moreover, the principles developed here can be applied to build tools that help manage major risks in other economic sectors too. Overall, MATCH strengthened strategic and informed action, which is necessary at multiple levels of an organization, to combat major societal risks, such as environmental degradation.

Ridge‐furrow plastic film mulching farming for sustainable dryland agriculture on the Chinese loess plateau

AbstractThis paper describes the progress of dryland farming development by comparing the ridge‐furrow plastic film mulching (RFM) system with conventional cultivation in the Chinese Loess Plateau, where the climate is cool and semi‐arid or subhumid prone to drought, and dryland farming dominates. The barren soil dominated by eolian sedimentary loess is loose and erosive. For thousands of years, increasing human population pressure and high‐intensity disordered land use have led to serious ecosystem degradation. Since the 1950s, large‐scale and long‐term construction of terraced fields have effectively reduced the soil erosion potential, and such fields have become more and more convenient for mechanized large‐area production. Since the beginning of the 21st century, the crop cultivation system based on the RFM has been widely promoted. Compared with previous cropping systems, the crop productivity in the RFM system is double or multiple times greater. Soil moisture has become favorable. Soil organic C content has been controlled or increased. Most importantly, the RFM system has promoted the coordinated development of grain, forage, and livestock, and favorable market results. It has vigorously promoted the fight against poverty and the realization of the goal of building a moderately prosperous society in dryland areas. Therefore, ridge‐furrow mulching is the key basis for the sustainable development of the dryland farming system on the Loess Plateau.

Assessing temporal trends of soil erosion and sediment redistribution in the Hexi Corridor region using the integrated RUSLE-TLSD model

Accurately evaluating soil water-erosion dynamics and drivers is crucial for mitigating soil and water loss. To simulate the potential or net soil erosion process in China’s Hexi region (a 2.3 × 105 km2 area including three river basins), this study attempted to integrate the transport limited sediment delivery (TLSD) function within the revised universal soil loss equation (RUSLE) model (the spatial resolution of the maps was 90 × 90 m). A geographically weighted regression model was used to evaluate the contribution of influencing factors to the net water-erosion rate and the soil and water conservation benefits of the “Grain to Green Program” (GTGP) (The area proportion of land types in 2015: 6.84% (cultivated land), 3.48% (forest land), 21.68% (grassland), 66.69% (unused land), 0.75% (water), and 0.56% (construction land). The results revealed that the RUSLE-TLSD model could reliably simulate the soil erosion process in Hexi (the Nash-Sutcliffe model efficiency coefficient exceeded 0.602). The potential water erosion rate was between 6.24 and 31.01 t/ha/a from 1982 to 2015, and the net water erosion rate declined slightly, with a slope of −0.0029. Water erosion was severe in high-altitude areas (altitude > 3306 m) with slopes of more than 21° and annual precipitation above 235 mm and weak in low-altitude areas (altitude <1920 m) with slopes less than 4° and annual precipitation below 114 mm. Nearly 10% of the Qilian Mountain National Nature Reserve (QMNNR) areas experienced intensive erosion, and nearly 29% of the QMNNR areas experienced sediment deposition. Slope was the primary factor affecting soil erosion. Extreme precipitation directly aggravated the water-erosion risk, and this factor should be given increased attention particularly in arid and semi-arid regions. The GTGP effectively reduced water soil erosion caused by extreme precipitation and improved water retention and soil consolidation in Hexi.

Development of an erosion model for Langat River Basin, Malaysia, adapting GIS and RS in RUSLE

This study is aimed to predict potential soil erosion in the Langat River Basin, Malaysia by integrating Remote Sensing (RS) and Geographical Information System (GIS) with the Revised Universal Soil Loss Equation (RUSLE) model. In RUSLE model, parameters such as rainfall erosivity factor (R), soil erodibility factor (K), slope length and steepness factor (LS), vegetation cover and management factor (C) and support practice factor (P) are determined based on the input data followed by the spatial analysis process in the GIS platform. Rainfall data from 2008-2015 are collected from the 29 rain gauge stations located within the study area. From the analysis, the magnitude of RUSLE model obtained corresponding to the parameter R, K, LS, C and P factors is varied between 800 to 3000 MJ mm ha− 1 h− 1 yr− 1, 0.035–0.5 Mg h MJ− 1 mm− 1, 0–73.00, 0.075–0.77 and 0.2–1.00, respectively. Findings of this study indicates that based on the calculated RUSLE parameter values, about 95% of the Langat River Basin area have been classified as a very low to a low erosion vulnerability. Findings of this study would greatly benefits a decision maker in proposing a suitable soil management and conservation practices for the river basin.

A GIS-based assessment of the potential soil erosion and flood hazard zones in Ekiti State, Southwestern Nigeria using integrated RUSLE and HAND models

Soil loss estimation and flood hazard mapping cannot be overemphasized due to their environmental, economic and societal concern. Thus, the main objective of this study was to assess the potential soil erosion and flood hazards zones using Revised Universal Soil Loss Equation (RUSLE) and Hand Above Nearest Drainage (HAND) models, respectively for appropriate conservation and prevention measures in Ekiti State, Southwestern Nigeria. The result reveals annual soil erosion ranges from 0 to 889 t ha−1 year−1. The estimated total annual soil loss in the state was around 1.5 million tonnes, of this, 193223.3 tonnes which covers 7508 ha was lost at a rate much greater than the tolerable soil loss rate. Soil erosion vulnerability mapping was done using six (6) categories of soil loss severity from slight to very severe. Soil erosion rates varied from 0.21 t ha−1 year−1 in forests to 1.69 t ha−1 year−1 under bare soils. The very steep slope category had the highest soil erosion rate of 15.07 t ha−1 year−1 while the gentle slope regions had the least soil erosion rate of 0.39 t ha−1 year−1. About 23% of the area which covers 115847.58 ha was prone to high flood hazard whereas 15.69% (80932.30 ha) was moderately susceptible to flood risk. Approximately 15% of the area was susceptible to low flood hazard zone while 44.90% were vulnerable to very low flood occurrence. LULC has significant effect on the spatial pattern of soil loss in the study area. Potential soil loss risk zones were highly related to the degree and inclination of slope. The reported results can serve as preliminary information to determine erosion and flood hotspots in the study area and as input for policy decision for disasters prevention and conservation measures.

Identification of Soil Conservation Priority Area, in Jedeb River Watershed East Gojjam Zone, Amhara Region, Ethiopia

Soil erosion is a major environmental problem that threatens world food production; it can be described as the removal of organic as well as inorganic soil surface materials by wind and water. This (e present) study aims to identify the most erosion vulnerable sub-watersheds for planning appropriate conservation intervention and restoration measures in Jedeb watershed. Revised Universal Soil Loss Equation (RUSLE) integrated with satellite remote sensing (RS) and geographical information system (GIS) has been applied to calculate potential soil loss at sub-watershed level. The parameters of RUSLE model were estimated using remote sensing data and ArcGIS software. The rainfall erosivity R-factor was found from 3209.6 to 3896.69 MJ.mm/ (ha.h), soil erodibility K-factor varies from 0.1 to 0.25 t ha h/ (ha MJ mm), Topographic (LS factor) ranging from 0.19 to 6.7, C-factor varies 0.01 to 0.25 and support practice P-factors from 0.1 to 1. The total annual soil loss potential of the study area was found 1,383,158 t/ yr from the total watershed area of 29,633 ha. Average annual soil loss at sub-watersheds level was estimated from 29.275 to72.529 t/ha/year and mean annual soil loss of the entire watershed was 46t/ha/year. The study results indicated that potential soil erosion rate in the watershed was ranged into four priority categories from high to extremely severe. Three sub-watersheds covering 22.975% of the watershed shows very severe mean soil loss rate, two sub-watersheds was found severe mean soil rate which covered 19.014%, eight sub-watershed were existed under very high mean soil loss rate covers 47.59% and Three sub-watersheds were found in the high soil loss rate and covers 10.42%. Sever and extremely severe micro watersheds demand immediate attention in terms of management and planning perspective. Soil and water conservation structure was recommended and designed based on peak runoff rate, soil type, slope of the land, land use type and soil erosion hazard . Keywords : Soil Erosion; RUSLE; GIS; Soil Conservation; Jedeb watershed; Ethiopia DOI: 10.7176/JNSR/10-9-02 Publication date: May 31 st 2020

Land use and Land Cover change and its resultant erosion susceptible level: an appraisal using RUSLE and Logistic Regression in a tropical plateau basin of West Bengal, India

Soil erosion trend depends on effective land use and land cover dynamics since overwhelming population growth in tropical region. The objective of this paper is to assess potential mean annual soil erosion rate, and conversion of erosion class incorporate with land use and land cover change in plateau fringe, undulating and low land of Kangsabati basin using Revised Universal Soil Loss Equation (RUSLE) and multiple logistic regression (MLR). Both models denote potential mean soil erosion zone as 55% corresponds at low level in low land than medium level as 30% in undulating topography and high level as 15% in plateau fringe site. RUSLE indicates erosion rate increases with expanding area in degraded forest (169 ton ha−1 year−1, 137 km2), dense forest (134 ton ha−1 year−1, 55 km2) and settlement area (30 ton ha−1 year−1, 105 km2), whereas erosion rate decreases with reducing the area in barren land with laterite outcrop (− 154 ton ha−1 year−1, − 93 km2), double crop (− 40 ton ha−1 year−1, − 201 km2) and single crop yield (− 1 ton ha−1 year−1, − 62 km2) from 2002 to 2016. MLR predicts barren land with laterite outcrop and dense forest play a crucial role to determine the erosion susceptibility in plateau fringe, while degraded forest and single crop signify erosion susceptibility in undulating topography. Settlement and double crop are more significant in low land with proper validation. Model comparison depicts same class conversion finds out as 63.73% (low-to-low class, 41%) in low land, whereas high-to-low class finds in undulating topography (23%) and low-to-high class in plateau fringe (13%).

The diversity of erosion control products and implications for wildlife entanglement

I n the United States, roads are prominent across the landscape, negatively impacting wildlife and ecological processes via road mortality (Brady and Richardson 2017). The extensive roadway system in the United States requires consistent maintenance that results in soil erosion potential. For example, as of August of 2019 in Texas, there were 6,739 active roadway projects, with another 6,448 projects listed to begin within the next four years (Texas Department of Transportation 2019). Despite regulatory and mitigation efforts, soil erosion and stream sedimentation are known to occur at construction sites due to exposure of the soil to environmental factors that influence erosion rates (Kaufman 2000; Benik et al. 2003). At the conclusion of construction projects, the Texas Department of Transportation (TxDOT) mandates that erosion control products (ECPs) are deployed on unpacked soil to prevent soil erosion potential and to promote plant growth (Babcock and McLaughlin 2013; Texas Department of Transportation 2018a). The TxDOT maintains an approved product list (APL) of all ECPs (ranging from mesh blankets to sprays and mulches) that can be used by contractors at the conclusion of a roadway construction project. To be placed on the APL, products must pass two performance standards: (1) protect the seedbed of an embankment or drainage channel from the loss of sediment during simulated rainfall or channel flow events, and (2) promote the establishment of warm-season, perennial vegetation …

Response of rainfall erosivity to changes in extreme precipitation in the Poyang Lake basin, China

Soil erosion by water is a serious ecological and environmental problem worldwide. Rainfall erosivity (RE), as well as its relationship to rainfall amount (erosivity density [ED]), is one of the most important factors influencing soil erosion as it measures the capability of rainfall to erode soils. Improving knowledge of the changing characteristics of RE and ED and their response to extreme precipitation is critical for risk assessment of soil erosion and for agricultural management. This study extended previous studies at the basin scale and investigated the temporal and spatial patterns of RE and ED in the Poyang Lake basin, China, and focused on their response to changes in extreme precipitation from 1960 to 2012. The results showed that nearly 80% of the annual RE was concentrated in summer and spring, and the highest ED also occurred during the same period. Summer was the most vulnerable season for potential soil erosion in the Poyang Lake basin. This was principally associated with the characteristics of precipitation in the different seasons. A trend analysis showed clear long-term positive changes in seasonal RE and ED during the study period. The risk of soil erosion in terms of RE and ED in the basin became increasingly higher than before. Spatially, the large RE and ED values were mainly found in the northeast of the basin. These trends and spatial patterns of RE and ED were primarily attributed to the intensification of extreme precipitation in the northeast of the Poyang Lake basin. These findings indicated that considering the strong role of extreme precipitation is essential for the soil erosion control, land management, and agricultural production in the Poyang Lake basin, as well as in other areas.

Estimating the extent of soil degradation of Weito Watershed in lower Rift Valley Basin: Southern Ethiopia

In this study, Revised Soil Loss Equation (RUSLE) was used to quantify the potential soil erosion in Weito Watershed. Rainfall data, soil data, DEM data and landuse-land cover data were used as input data sets to generate RUSLE factor values. RUSLE factors such as R_ the erosivity factor, K_the soil erodibility factor, LS_ thetopographic factor, C_ the crop management factor, and P_ the conservation support practice was analyzed and superimposed using raster calculator in ArcGIS10.1 to estimate and map the annual soil loss. The results showed annual soil loss ranging from 0 to 210 tons/ha and mean annual soil loss rate of 110ton/ha/yr. The annual soil loss rate in the western and south western part of the watershed was mainly identified as high and severe and hence, requires special attention with an immediate soil conservation practice.

Soil erosion assessment in a humid, Eastern Himalayan watershed undergoing rapid land use changes, using RUSLE, GIS and high-resolution satellite imagery

The study aims to understand land degradation in the $$\approx 2000 \hbox {ha}$$, humid and mountainous Papung khola catchment in the Sikkim Sivalik Range using the revised universal soil loss equation on a GIS platform. The catchment drains into the Tista River and is part of the data-sparse Eastern Himalayan ecoregion. Catchment land-use is changing from broadleaf forests to mixed land-use driven by rising population, and livelihood changes from primary production (forestry, agriculture) to service sectors (tourism, trade, construction). The study uses data on soil characteristics, ground and satellite precipitation and aerial land cover to predict potential soil erosion. Results indicate transitions in land cover/land use from forests to agriculture, disturbances due to construction and the potential increase in frequency of extreme climate events posing a unique risk to soils of the steep catchment causing decrease in soil cover and resultant loss of land productivity. The catchment can be currently categorized under a “very low” or “slightly erosive” regime (mean erosion rates 3.53 $$\hbox {t}\,\hbox {ha}^{-1}\, \hbox {year}^{-1}$$, with > 99% under cover of < 5 $$\hbox {t}\,\hbox {ha}^{-1}\, \hbox {year}^{-1}$$) with around three-quarters of the catchment under forest cover. High precipitation, intensification of diurnal and seasonal wetting-drying cycles, human disturbances to the top soil and rapid land use/land cover changes combining with the extreme topography and slow soil development is driving land degradation, which may stymie sustainable development and livelihood diversification in the future. Moderate erosion levels of $$\approx $$ 10 $$\hbox {t}\,\hbox {ha}^{-1}\, \hbox {year}^{-1}$$ can be expected in the future in areas with intact vegetation cover leading to complete top soil loss given the shallow profile depths.

Spatial and temporal characteristics of soil conservation service in the area of the upper and middle of the Yellow River, China

Soil erosion is an important environmental problem in the area of the upper and middle of the Yellow River (AUMYR), China, one of the most severe soil erosion areas in the world. It is significantly influences on the ecological security and sustainable development of the region. Soil conservation (SC) service, as one of the most important regulating services provided by ecosystems, can alter soil and water processes and improve ecosystem services that ensure human welfare. Investigations of spatial and temporal characteristics of SC service play important roles in soil erosion control and ecosystem protection in AUMYR. In the past several years, restoration projects (e.g. the Grain-for-Green project) were implemented to improve SC in most of AUMYR. It is needed to evaluate the change of SC service brought about by the projects. This study carries out quantitative spatial analysis of SC services through Universal Soil Loss Equation (USLE) model and geographic information system (GIS) manipulation based on various datasets, such as remote sensing image, digital elevation model (DEM), climate, and land use/cover maps. Soil retention calculated as potential soil erosion (erosion without vegetation cover) minus actual soil erosion was applied as indicator for SC service. The results are like these. (1) The total amount and mean capacity of SC service in AUMYR were 7.22 billion t/a and 142.2 t/hm2·a in 2000 and 10.19 billion t/a and 200.8 t/hm2·a in 2010, respectively. South-east AUMYR exhibited a much higher capacity of soil retaining than the north-west. (2) Forest ecosystems displayed higher SC capacity than other types of ecosystems. Moreover, the SC capacity of ecosystems increased with the increasing of slope gradient. (3) Variations of SC rate (the ratio of SC to potential soil erosion in percentage) in different units (ecosystem, slope zone and city) were relatively small and ca. 90% of potentially eroded soil was retained in AUMYR. (4) The spatial characteristics of SC service in AUMYR were primarily controlled by topography at the regional scale. Vegetation cover restoration significantly improved the capacity of SC service in AUMYR in the midst year of 2000 and 2010. The results revealed that ecological restoration efforts significantly enhanced SC service of ecosystem in the study area.

Landscape planning of tobacco plantation based on erosion potential in Eastern Region of Mount Sindoro Temanggung

Mount Sindoro slope is a tobacco plantation area. Based on variations in slope, there is erosion potential on most of the slopes. This study aimed to determine the way of structuring tobacco plantations in the eastern region of Mount Sindoro due to intensive land use. This research was conducted in Gunungsari Village, Bansari District, Temanggung Regency, from April to July 2018. This research was conducted using a survey method and continued with the determination of the level of soil erosion potential on area A (more than 20% slope), area B (15-20%slope) and area C (less than 15% slope) using USLE method. Landscape planning was carried out based on the application of land conservation methods with the main purpose of reducing the level of erosion potential using agronomic and mechanical methods. The results show that the actual erosion potential of area A, B and C is 42.67 tons/ha/year, 44.81 tons/ha/year and 31.80 tons/ha/year, respectively, and is categorized as moderate to severe erosion level. The application of agronomic methods in the form of intercropping systems of tobacco and peanuts could reduce the erosion potential from 42.67 to 32.43 tons/ha/year (area A); from 44.81 to 33.61 tons/ha/year (area B) and from 31.80 to 23.85 tons/ha/year (area C). Meanwhile, the application of the ridge terraces and bench terraces, consecutively, reduced erosion potential from 42.67 to 6.40 and 1.71 tons/ha/year (area A); from 44.81 to 6.72 and 1.79 tons/ha/year (area B); and from 31.80 to 4.77 and 1.27 tons/ha/year (area C). Thus, it can be concluded that bench terraces is more effective in reducing erosion potential than ridge terraces.

Erosion and Sediment Control Best Management Practices in Agricultural Farms for Effective Reservoir Sedimentation Management at Cameron Highlands

For many years, lands in Cameron Highland have been opened and leveled for agricultural farming and intensive crop production. Land-disturbing activities such as agricultural operations that are conducted on regions with steep slopes leads to a high potential of soil erosion, sedimentation and landslide occurrences. As a results, this phenomenon producing large amounts of sediment transported and deposited to the receiving waters or reservoirs. The development of best management practices (BMPs) for agricultural activities is an important step towards minimizing the amount of soil erosion and landslide incidents in Cameron Highlands. Therefore, this Erosion and Sediment Control Guideline for Agricultural Activities in Hilly Area aims to minimize erosion and sedimentation from the agricultural area in Cameron Highlands especially in the scope of reservoir sedimentation management. There numbers of steps taken in order to establish this guidelines. The first step is to define the scope with the purpose of the guideline and conduct a literature review. In order to assess the quality and feasibility of the study to formulate the frameworks, engagement with stakeholders was conducted. Lastly is to undergo review and update based on the recommendations by related stakeholders. Finally, before the establishment of guidelines, all recommendations by related stakeholders are take in account that consists of Best Management Practices components which will be applied in the agricultural area to mitigate issues and problems especially in erosion control and reservoir sedimentation management. The Erosion Control Measures are including agronomic measures, soil management, mechanical methods and Rainwater Harvesting Techniques. Subsequently, these measures are used to apply in open or sheltered farming to control the erosion and sedimentation issues based on the erosion risk level. As a conclusion, this guideline will be useful for the stakeholders especially to local community, dam owners and local authority to mitigate and solve the issues related to erosion and sedimentation in hilly agricultural area.

Can Management Practices Enhance Corn Productivity in a Rye Cover Crop System?

Cereal rye (Secale cereale L.) cover crops (RCC) have good potential to take up residual NO3 between grain crops and reduce loss to surface waters. However, studies in Iowa have shown a 6% corn (Zea mays L.) yield reduction in no‐till when grown following a RCC. The objective of this research was to study tillage and starter N agronomic practices that have potential to improve corn yield in a RCC system. This study was conducted at four sites from 2014–2016 with corn grown in rotation with soybean [Glycine max. (L.) Merr.]. Treatments included rye aerial broadcast into soybean before leaf drop and no RCC, tillage or no‐till, and starter N fertilizer (34 kg N ha−1) or no starter. The main fertilizer N was sidedressed. The aerial rye sowing, especially with dry fall conditions and planned RCC termination in the spring at 15–20 cm height, resulted in non‐uniform RCC stand with low biomass and N content (range 6–36 kg N ha−1). However, the profile soil NO3–N at rye termination was decreased, approximately the same amount as the RCC aboveground N content. The V6 stage corn height and V10 stage canopy sensing indexes increased with tillage and starter. Overall, corn yield was reduced with the RCC (0.2 Mg ha−1), tillage increased yield (3%), but starter N did not increase yield despite consistent increased early corn growth. If soil erosion potential is low, springtime tillage would be a practice to help improve corn early growth and yield in a RCC system.Core Ideas A cereal rye cover crop preceding corn can result in reduced grain yield. Rye cover crop did not affect corn plant population. Starter N improved early corn growth but not grain yield. Corn yield was 1.6% reduced with the rye cover crop, but tillage improved yield by 3%.

D-RUSLE: a dynamic model to estimate potential soil erosion with satellite time series in the Italian Alps

ABSTRACTSoil erosion is addressed as one of the main hydrogeological risks in the European Union. Since the average annual soil loss rate exceeds the annual average formation rate, soil is considered as a non-renewable resource. Besides, human activities, human-induced forces and climate change have further accelerated the erosion processes. Therefore, understanding soil erosion spatial and temporal trends could provide important information for supporting government land-use policies and strategies for its reduction. This paper describes the Dynamic Revised Universal Soil Loss Equation (D-RUSLE) model, a modified version of the well-known RUSLE model. The RUSLE model formulation was modified to include variations in rainfall erosivity and land-cover to provide more accurate estimates of the potential soil erosion in the Italian Alps. Specifically, the modelling of snow occurrence and the inclusion of Earth Observation data allow dynamic estimation of both spatial and temporal land-cover changes. Results obtained in Val Camonica (Italy) show that RUSLE model tends to overestimate erosion rates in Autumn/Winter because not considering snow cover and vegetation dynamics. The assimilation of satellite-derived information in D-RUSLE allows a better representation of soil erosion forcing, thus proving a more accurate erosion estimate for supporting government land-use policies and strategies for reducing this phenomenon.

Post-fire wood mulch for reducing erosion potential increases tree seedlings with few impacts on understory plants and soil nitrogen

Following high-severity wildfire, application of mulch on the soil surface is commonly used to stabilize slopes and limit soil erosion potential, protecting ecosystem values at risk. Despite the widespread use of mulch, relatively little is known about its effects on ecosystem recovery and soil processes important for plant re-establishment. Following a high-severity wildfire in a Colorado lodgepole pine forest, we studied the effects of both mulch material and application rate on plant recovery and the relative importance of soil abiotic conditions and microbial substrate availability as drivers of plant community development over the first four years of recovery. Mulches were applied to experimental plots in a randomized complete block design immediately following the High Park Fire in July 2012. Treatments included wheat straw, wood strands, and wood shreds applied at two coverage rates (standard and high). Two controls, non-mulched and a microbially-neutral synthetic mulch, were included in each block to assess the relative importance of mulch effects on abiotic versus biotic dynamics. Plant and soil monitoring occurred at least annually for four-years post fire. Understory plants increased in total cover and shifted in composition over time, but these trends were largely unaffected by mulch type or application rate. Non-native understory plant species were not abundant at the end of this experiment, but their cover was higher in plots treated with wheat straw and high-rate wood strands compared to non-mulched control. Lodgepole pine seedling densities were higher in wood shred and mulched control treatments than in wheat straw and non-mulched control treatments. Because there were few effects of mulch treatments on plant available nitrogen, it is likely that effects of mulch on soil abiotic conditions (moisture and temperature) drove ecosystem responses in this system. Our findings indicate wood mulches can provide soil protection for many years and accelerate lodgepole pine establishment following wildfire with few negative near-term effects on plant recovery. In systems such as this, post-fire application of wood mulch can help managers meet site protection goals with minimal impacts on plant recovery.

Identification of spatially distributed hotspots for soil loss and erosion potential in mining areas of Upper Damodar Basin – India

Limited measurements of soil erosion, sediment transport and deposition due to coal mining activities hamper the planning for soil and water management in large coalfields. Management of erosion in these areas requires the identification of vulnerable zones. In this study, a modified Universal Soil Loss Equation model coupled with Analytic Hierarchy Process has been used to develop an Erosion Potential Index (EPI) to identify probable zones of soil erosion in the Upper Damodar Basin (UDB). The Damodar river valley has been subjected to severe environmental contamination over the years due to large scale mining and industrial activities. The results revealed that north-western and the central part of the UDB lied in the high EPI zone. Revised Universal Soil Loss Equation (RUSLE) model was used to estimate the soil loss for the UDB. The results of the RUSLE model revealed that the soil loss in the study area varied from a minimum of 0 to a maximum of 91.34 t ha−1 yr−1 in some areas. The spatial distribution of soil loss in the UDB was classified into 5 categories (Very Slight, Slight, Moderate, Severe and Extremely Severe). From results it was observed that about 959.9 km2 or 22% of the total study area lied in the severe soil loss zone i.e., soil losses in these areas ranged between 20 and 40 t ha−1 yr−1. Most of these areas were located in the vicinity of coal mining areas. Although, the lack of available data may impair the prediction accuracy of the proposed model at such a large watershed scale. However, the results of the proposed approach indicate usefulness in identifying erosion hotspots in large distributed watersheds with limited data.

Long-term vegetation response following post-fire straw mulching

BackgroundStraw mulching is one of the most common treatments applied immediately post fire to reduce soil erosion potential and mitigate post-fire effects on water quality, downstream property, and infrastructure, but little is known about the long-term effects on vegetation response. We sampled six fires that were mulched between 9 and 13 years ago in western US dry conifer forests. We compared understory plant species diversity and abundance, tree seedling density and height by species, and fractional ground cover on mulched and unmulched paired plots.ResultsMulch did not influence understory plant diversity, species richness, or fractional ground cover. However, on mulched plots, tree seedlings grew taller faster, especially on north-facing aspects, and there was slightly more graminoid cover. Mulch did not affect overall tree seedling density, but there were fewer ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and more Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in mulched areas, especially on south-facing slopes.ConclusionsManagers will be able to weigh the long-term implications of mulching against the short-term reductions in soil erosion potential. While there are many concerns about vegetation suppression and exotic species introduction from using straw mulch, our study suggests that the long-term effects are subtle 9 to 13 years after post-fire mulching.

Temporal and abiotic fluctuations may be preventing successful rehabilitation of soil‐stabilizing biocrust communities

Land degradation is a persistent ecological problem in many arid and semiarid systems globally (drylands hereafter). Most instances of dryland degradation include some form of soil disturbance and/or soil erosion, which can hinder vegetation establishment and reduce ecosystem productivity. To combat soil erosion, researchers have identified a need for rehabilitation of biological soil crusts (biocrusts), a globally relevant community of organisms aggregating the soil surface and building soil fertility. Here, the impact of plant and biocrust cover was tested on soil erosion potential in the piñon-juniper woodlands of Bandelier National Monument, New Mexico, USA. Biocrusts were found to be similarly influential to vascular plants in reducing erosion, largely acting by promoting surface roughness. The potential to rehabilitate biocrusts within the Monument was also tested. Plots were inoculated on eroding soils before the summer monsoon with greenhouse-cultured biocrusts. In a full-factorial design, treatments to reduce or halt erosion were administered to the inoculated plots and their paired controls. These erosion-reduction treatments included barriers to overland flow (flashing), slash placement, and seeding of vascular plants. Dynamic changes to soil stability, penetration resistance, and extractable soil nutrients were observed through time, but no strong effects with the addition of biocrust inoculum, seeding, or erosion intervention treatments were seen. The results do suggest possible ways forward to successfully rehabilitate biocrust, including varying the timing of biocrust application, amending inoculum application with different types of soil stabilization techniques, and adding nutrients to soils. The insights gleaned from the lack of response brings us closer to developing effective techniques to arrest soil loss in these socially and ecologically important dryland systems.