Land management effects on catchment-scale soil erosion processes and sediment connectivity in lowland agricultural landscapes

Greatest challenge of recent agricultural land management is to cover increasing production demand under accelerating soil degradation and climate change. Land management is combination of land use management (including soil cover), and landscape structure (or landscape design) management. In Chernozem region in South-West Carpathian Foreland, important land management changes took place in mid-20th century, including increase of field size, tillage intensification and decrease in cultivated areas. This study evaluates effect of these land management changes on soil erosion and sediment connectivity patterns. Extensive database of soil profiles (>800 drillings), and soil patterns from remote sensing, modelled water and tillage erosion patterns (WATEM/SEDEM)and connectivity patterns. Structure of narrow elongated fields before 1950 have supported less erosive managment, and field size and current aggricultural managment increased sediment connectivity and soil erosion

Jasne plamy na czarnoziemach - wskaźnik procesów erozyjnych oraz zmian w rzeźbie

Soil erosion strongly influences the Chernozems in loessie hilly land in the Slovak part of the Danube Lowland. It leads to transformation of the original humus horizon to a brighter less humic horizon, which is easily distinguishable in terrain or on aerial photographs. Soil profile truncation and accumulation were analysed in the areas of bright patches. Difterences in soil profiles, thereby indicating relief lowering or elevation within and between bright patches, were described.Na użytkowanych rolniczo obszarach czarnoziemnych jasne plamy na powierzchni gruntu są dowodem procesów erozyjnych, jakie zachodzą na stokach. Plamy te powstają w wyniku działania erozji wodnej, eolicznej i uprawowej. Są to miejsca, gdzie poziom orny gleby jest przekształcony do tego stopnia, że różni się jasnym kolorem od ciemnego poziomu próchnicznego czarnoziemów. Do oceny intensywności i kartowania zasięgu tego zjawiska wykorzystano zdjęcia lotnicze i satelitarne. W oparciu o wiercenia stwierdzono, że miejsca te charakteryzują się zróżnicowaną głębokością poziomu próchnicznego gleby oraz jego kolorem. Parametry te mogą być także zmienne w obrębie jednej plamy. Najbardziej zerodowane miejsca (plamy) znajdują się w górnej części stoku. Na obszarach położonych niżej najczęściej występują gleby niezerodowane lub deluvialne, w których dochodzi do akumulacji jaśniejszego materiału pochodzącego z górnych parti stoku. Może to prowadzić do błędów przy interpretacji zdjęć, kiedy miejsca, w których nastąpiła akumulacja - podniesienie powierzchni, są interpretowane jako miejsca dotknięte erozją, powodującą obniżenie terenu. Dlatego też celem dalszych badań będzie sprawdzenie możliwości wykorzystania bardziej zaawansowanych metod do analizy obszarów występowania jasnych plam

Soil translocation under pre-sowing tillage operations on loess slope with various inclination

Soil translocation under pre-sowing operation performed with cultivator and harrow was analysed in the studies carried out on loess slopes of various inclination. Results showed that soil displacement was dependent on direction and velocity of tillage implementation, and slope inclination. Similar amount of soil was displaced, both down and up-slope, at slopes of 5-5.3%. Above this range, a net translocation of soil mass in down-slope direction prevailed. It's magnitude depended on slope inclination and temporal changes of velocity, being adjusted to configuration of short and concave slope. For the whole analysed slope on the average inclination of 7.3%, net soil displacement down-slope was 5.6 kg m⁻¹. Studies showed that tracers installed at soil depth of 0-15 cm were displaced furthest, on distances ranged from 27 to 62 cm. For these tracers, the translocation distance was strongly positively correlated with slope for down-slope, and negatively - for up-slope tillage

Main issues for preserving mediterranean soil resources from water erosion under global change

Soil resources are important for the socioeconomic development of the Mediterranean area. Their durability may be threatened because of intense erosion processes that result in severe degradation in the field (on-site effects) and downstream degradation (off-site effects). Based on the literature and results obtained during several research projects, this paper presents the main lessons and challenges dealing with Mediterranean soil resources under global change. After a review of the main drivers of Mediterranean soil erosion and the main impacts of water erosion processes, the paper highlights that the nature and intensity of active erosion processes are as diverse as the mosaic of the Mediterranean landscape. It then discusses the expected evolution of Mediterranean soil resources under global change and illustrates the prevalent influences of land use (partly depending on climatic constraints) on the evolution of erosion risk and soil vulnerability. Finally, it details some main challenges for the future of Mediterranean soil resources dealing with a better knowledge of factors and processes involved in soil erosion, a better evaluation of soil vulnerability through a combined quantitative and qualitative soil erosion approach, and the need for a site-specific conservation strategy for Mediterranean soil resources

Multilocus detection of wolf x dog hybridization in Italy, and guidelines for marker selection

Hybridization and introgression can impact the evolution of natural populations. Several wild canid species hybridize in nature, sometimes originating new taxa. However, hybridization with free-ranging dogs is threatening the genetic integrity of grey wolf populations (Canis lupus), or even the survival of endangered species (e.g., the Ethiopian wolf C. simensis). Efficient molecular tools to assess hybridization rates are essential in wolf conservation strategies. We evaluated the power of biparental and uniparental markers (39 autosomal and 4 Y-linked microsatellites, a melanistic deletion at the β-defensin CBD103 gene, the hypervariable domain of the mtDNA control-region) to identify the multilocus admixture patterns in wolf x dog hybrids. We used empirical data from 2 hybrid groups with different histories: 30 presumptive natural hybrids from Italy and 73 Czechoslovakian wolfdogs of known hybrid origin, as well as simulated data. We assessed the efficiency of various marker combinations and reference samples in admixture analyses using 69 dogs of different breeds and 99 wolves from Italy, Balkans and Carpathian Mountains. Results confirmed the occurrence of hybrids in Italy, some of them showing anomalous phenotypic traits and exogenous mtDNA or Y-chromosome introgression. Hybridization was mostly attributable to village dogs and not strictly patrilineal. The melanistic β-defensin deletion was found only in Italian dogs and in putative hybrids. The 24 most divergent microsatellites (largest wolf-dog FST values) were equally or more informative than the entire panel of 39 loci. A smaller panel of 12 microsatellites increased risks to identify false admixed individuals. The frequency of F1 and F2 was lower than backcrosses or introgressed individuals, suggesting hybridization already occurred some generations in the past, during early phases of wolf expansion from their historical core areas. Empirical and simulated data indicated the identification of the past generation backcrosses is always uncertain, and a larger number of ancestry-informative markers is needed

Soil Mapping and Processes Modeling for Sustainable Land Management

Soil maps and models are indispensable tools in sustainable land management. The sustainable land use of our territory is fundamental to providing long-term socio-economic and environmental benefits. The risk of land degradation and corresponding declines in ecosystem services depends on the type of land use. Soil restoration can be extremely expensive, more than the implementation of sustainable land use practices. This is especially important in the context of climate change and the increasing pressure that a growing population places on soil resources, which is a global phenomenon. The objective of this chapter is to show the advantages of using soil mapping and modeling in sustainable land use planning and management. Soil mapping is fundamental to understand the distribution of soil properties, allowing us to implement sustainable practices in vulnerable areas and prevent land degradation. Soil indicators and models provide indispensable information for an accurate evaluation of land degradation status. Alone, or integrated with other disciplines, soil information is extremely important for understanding the causes of land degradation and implementation of sustainable land management. Accurate information and models are key tools for managers and decision makers to implement sustainable land use management policies

Temporal variability and time compression of sediment yield in small Mediterranean catchments : impacts for land and water management

Increased soil erosion, pressure on agricultural land, and climate change highlight the need for new management methods to mitigate soil loss. Management strategies should utilize comparable data sets of long-term soil erosion monitoring across multiple environments. Adaptive soil erosion management in regions with intense precipitation requires an understanding of inter-annual variability in sediment yield (SY) at regional scales. Here, a novel approach is proposed for analysing regional SY. We aimed to (i) investigate factors controlling inter- and intra-annual SY, (ii) combine seasonality and time compression analyses to explore SY variability and (iii) discuss management implications for different Mediterranean environments. Continuous SY measurements totalling 104years for eight small catchments were used to describe SY variability, which ranged from 0 to 271t/ha/year and 0 to 116t/ha/month. Maximum SY occurs in spring to summer for catchments with oceanic climates, while semi-arid or dry summer climates experience SY minimums. We identified three time compression patterns at each time scale. Time compression was most intense for catchments with minimum SY in spring to summer. Low time compression was linked to very high soil loss, low run-off and sediment production thresholds, and high connectivity. Reforestation, grassland and terracing changed SY magnitudes and time compression, but failed to reduce SY for large storm events. Periods with a high probability of high SY were identified using a combination of intra-annual SY variability, seasonality analysis, and time compression analysis. Focusing management practices on monthly flow events, which account for the majority of SY, will optimise returns in Mediterranean catchments