▶ Crop observations and agricultural statistics are combined. ▶ From them, intensity can be calculated at about 100 thousand points in EU27. ▶ Regression connects intensity classes to location ...factors. ▶ Maps of agricultural intensity for 5 EU-countries have been made. ▶ Heterogeneity of land use intensity is between and within countries and regions.
Spatial maps of agricultural intensity are needed for analyses of environmental issues, including biodiversity changes. We present a method to produce such maps for Europe. While most studies beyond farm level focus on land cover change only, this paper focuses on spatial variation in land use intensity and its dynamics.
Our method defines agricultural land use intensity in terms of nitrogen input. For arable land, it combines field observations with administrative-level statistics to assess probability of occurrence for three land use intensity classes. For grassland, it uses maps of livestock density to assess probability of occurrence for two intensity classes. Agricultural land is spatially allocated to intensity classes using an algorithm that downscales intensity changes simulated with an agricultural economic model.
Our results are 1km2 resolution maps of classified agricultural land use intensity in the year 2000. We illustrate the method by exploring changes in the spatial pattern of land use intensity for a financial policy reform scenario in the year 2025. Results indicate spatial heterogeneity in land use intensity across European countries, including large differences in intensity between countries, between regions, but also within regions.
Our method could be improved with smaller-resolution agricultural statistics and broader intensity indicators.
Land use change is an important determinant of hydrological processes and is known to affect hydrological parameters such as runoff volume, flood frequency, base flow, and the partitioning into ...surface flow and subsurface flow. The main objective of this research was to assess the magnitude of the effect of land use changes on runoff parameters, using the Baghsalian watershed in Iran as a case study site. At first, land use maps of years 1986 and 2012 were prepared using synthetic method, and then simulation was done based on land use changes in the 1986 to 2012 period. Land use map of year 2030 was simulated using CLUE-s model. Spatially distributed hydrological WetSpa model was used to simulate runoff at daily scale with land use maps of 1986, 2012, and 2030. Total volume of runoff, peak flow, and surface flow were compared. The accuracy of the WetSpa model simulation was assessed with the Nash-Sutcliffe efficiency, which had values of 0.61 and 0.56% for the calibration and validation dataset, respectively. The aggregation measure criterion was also calculated and had values of 64 and 62% for the calibration and validation periods, respectively. The main land use changes in Baghsalian watershed between 1986, 2012, and 2030 were the conversion of forest and rangeland to agriculture and residential land use types. Because of these conversions, simulated total runoff volume increased; and the rate of increase in surface runoff was larger than the rate of increase in subsurface runoff. In addition, surface and subsurface runoff increased in 2012 and 2030 compared to 1986 land use map, but the rate of increase of subsurface runoff was less than surface runoff.
The ability of water to transport and transform soil materials is one of the main drivers of soil and landscape development. In turn, soil and landscape properties determine how water is distributed ...in soil landscapes. Understanding the complex dynamics of this co-evolution of soils, landscapes and the hydrological system is fundamental in adapting land management to changes in climate. Soil-Landscape Evolution Models (SLEMs) are used to simulate the development and evolution of soils and landscapes. However, many hydrologic processes, such as preferential flow and subsurface lateral flow, are currently absent in these models. This limits the applicability of SLEMs to improve our understanding of feedbacks in the hydro-pedo-geomorphological system. Implementation of these hydrologic processes in SLEMs faces several complications related to calculation demands, limited methods for linking pedogenic and hydrologic processes, and limited data on quantification of changes in the hydrological system over time.
In this contribution, we first briefly review processes and feedbacks in soil-landscape-hydrological systems. Next, we elaborate on the development required to include these processes in SLEMs. We discuss the state-of-the-art knowledge, identify complications, give partial solutions and suggest important future development. The main requirements for incorporating hydrologic processes in SLEMs are: (1) designing a model framework that can deal with varying timescales for different sets of processes, (2) developing and implementing methods for simulating pedogenesis as a function of water flow, (3) improving and implementing knowledge on the evolution and dynamics of soil hydraulic properties over different timescales, and (4) improving the database on temporal changes and dynamics of flow paths.
This study discusses the complex late Holocene evolution of the Gediz River north of Kula, western Turkey, when a basaltic lava flow dammed and filled this river valley. Age control was obtained ...using established and novel feldspar luminescence techniques on fluvial sands below and on top of the flow. This dating constrained the age of the lava flow to 3.0–2.6ka. Two damming locations caused by the lava flow have been investigated. The upstream dam caused lake formation and siltation of the upstream Gediz. The downstream dam blocked both the Gediz and a tributary river, the Geren. The associated lake was not silted up because the upstream dam already trapped all the Gediz sediments. Backfillings of the downstream lake are found 1.5km upstream into the Geren valley. The downstream dam breached first, after which the upstream dam breached creating an outburst flood that imbricated boulders of 10m3 size and created an epigenetic gorge. The Gediz has lowered its floodplain level at least 15m since the time of damming, triggering landslides, some of which are active until present. The lower reach of the Geren has experienced fast base level lowering and changed regime from meandering to a straight channel. Complex response to base level change is still ongoing in the Geren and Gediz catchments. These findings are summarized in a diagram conceptualizing lava damming and breaching events. This study demonstrates that one lava flow filling a valley floor can block a river at several locations, leading to different but interrelated fluvial responses of the same river system to the same lava flow.
•A young lava flow was age-constrained using novel feldspar Luminescence.•Fluvial response to two dam events by a lava flow was different, but interrelated.•A conceptual framework of damming, breaching and response is presented.•Complex fluvial response to past damming-breaching events is still on-going.
Physically-based, catchment scale sediment delivery models have become increasingly complex, sophisticated and are suitable for a diverse range of environmental contexts. However, in their attempts ...to best represent the physical processes of erosion and deposition, these models require large and detailed input datasets. When such data are unavailable, annual sediment yield models are relied upon. However, in this class of models, widely available data such as daily precipitation and discharge are disregarded resulting in a reduction in temporal accuracy. To fill this scientific and management gap, the landscape evolution model LAPSUS was adapted (LAPSUS-D) for a meso-scale catchment to model sediment yield on a daily resolution. The water balance component within the model enables the calibration of the model in terms of water discharge with measured daily discharge at the outlet. This methodology is especially important when modeling sediment yield from catchments which are ungaged catchments in terms of sediment, but where hydrological data are available. As the simulation of sediment yield was the main objective of the study, the calibration focused on peak discharge. The focus on peak discharge provides insight into the capability of the model to generate, route and deliver sediment at the outlet of a meso-scale catchment. LAPSUS-D has daily temporal resolution and requires a 10 to 30m pixel size DEM, soil map, land-use map and daily hydrological records (precipitation and discharge). In this paper we present the first assessment of the hydrological model performance and an analysis of the sensitivity of the model to input parameters. Our study site is a 23-km2 catchment in Upper Nysa Szalona, southwest Poland with temperate climate.
Results show that the model can reliably predict peak discharge, which is expected in future studies to allow reliable estimates of sediment transport capacity, redistribution and yield.
•First test of the hydrological functioning of a new sediment delivery model LAPSUS-D•Works on meso-scale: both spatial (20–200km2) catchments and daily time-steps•Only needs: DEM, soil map, land-use map and daily precipitation and discharge•First test in Polish catchment shows good results for peak discharge simulation.•Good hydrological prediction gives a good indication for sediment dynamics.
With climate change and an ever-increasing human population threatening food security, developing a better understanding of the genetic basis of crop performance under stressful conditions has become ...increasingly important. Here, we used genome-wide association studies to genetically dissect variation in seedling growth traits in cultivated sunflower (Helianthus annuus L.) under well-watered and water-limited (i.e., osmotic stress) conditions, with a particular focus on root morphology. Water limitation reduced seedling size and produced a shift toward deeper rooting. These effects varied across genotypes, and we identified 13 genomic regions that were associated with traits of interest across the two environments. These regions varied in size from a single marker to 186.2 Mbp and harbored numerous genes, some of which are known to be involved in the plant growth/development as well as the response to osmotic stress. In many cases, these associations corresponded to growth traits where the common allele outperformed the rare variant, suggesting that selection for increased vigor during the evolution of cultivated sunflower might be responsible for the relatively high frequency of these alleles. We also found evidence of pleiotropy across multiple traits, as well as numerous environmentally independent genetic effects. Overall, our results indicate the existence of genetic variation in root morphology and allocation and further suggest that the majority of alleles associated with these traits have consistent effects across environments.
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•We analyzed the SEM features for extrapolating soil mapping predictive models.•We compared the performance of several SEM models, as well as purely empirical models.•Model ...modifications for improving prediction reduce model extrapolation capabilities.•By using SEM it is possible to extrapolate a pedological conceptual model.
In theory, two separate regions with the same soil-forming factors should develop similar soil conditions. This theoretical finding has been used in digital soil mapping (DSM) to extrapolate a model from one area to another, which usually does not work out well. One reason for failure could be that most of these studies used empirical methods. Structural equation modelling (SEM) is a semi-mechanistic technique, which can explicitly include expert knowledge. We therefore hypothesize that SEM models are more suitable for extrapolation than purely empirical models in DSM. The objective of this study was to investigate the extrapolation capability of SEM by comparing different model settings. We applied a SEM model from a previous study in Argentina to a similar soil-landscape in the Great Plains of the United States to predict clay, organic carbon, and cation exchange capacity for three major horizons: A, B, and C. We concluded that system relationships that were well supported by pedological knowledge showed consistent and equal behaviour in both study areas. In addition, a deeper understanding of indicators of soil-forming factors could strengthen conceptual models for extrapolating DSM models. We also found that for model extrapolation, knowledge-based links between system variables are more effective than data-driven links. In particular, model modifications can improve local prediction but harm the predictive power of extrapolation.
Cultivated sunflower (
L.) exhibits numerous phenotypic and transcriptomic responses to drought. However, the ways in which these responses vary with differences in drought timing and severity are ...insufficiently understood. We used phenotypic and transcriptomic data to evaluate the response of sunflower to drought scenarios of different timing and severity in a common garden experiment. Using a semi-automated outdoor high-throughput phenotyping platform, we grew six oilseed sunflower lines under control and drought conditions. Our results reveal that similar transcriptomic responses can have disparate phenotypic effects when triggered at different developmental time points. Leaf transcriptomic responses, however, share similarities despite timing and severity differences (e.g., 523 differentially expressed genes (DEGs) were shared across all treatments), though increased severity elicited greater differences in expression, particularly during vegetative growth. Across treatments, DEGs were highly enriched for genes related to photosynthesis and plastid maintenance. A co-expression analysis identified a single module (M8) enriched in all drought stress treatments. Genes related to drought, temperature, proline biosynthesis, and other stress responses were overrepresented in this module. In contrast to transcriptomic responses, phenotypic responses were largely divergent between early and late drought. Early-stressed sunflowers responded to drought with reduced overall growth, but became highly water-acquisitive during recovery irrigation, resulting in overcompensation (higher aboveground biomass and leaf area) and a greater overall shift in phenotypic correlations, whereas late-stressed sunflowers were smaller and more water use-efficient. Taken together, these results suggest that drought stress at an earlier growth stage elicits a change in development that enables greater uptake and transpiration of water during recovery, resulting in higher growth rates despite similar initial transcriptomic responses.
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