Using high resolution LIDAR DEM to reconstruct historical network of lakes and wetlands in the Northern part of the Moldavian Plateau, NE Romania

A particular environmental feature of the northern part of Moldavian Plateau (NE Romania) is the large number of anthropic lakes along river courses. Even more, due to climatic, hydrological, hydrogeological and geomorphological settings and human activities (dominated by an extensive agriculture) this characteristic was mentioned and mapped in writen records and cartographic representations in many historical stages of the humanization of this region.  The need for watter supply have forced the inhabitants to build dams of various sizes along the entire river network. Over the time, many dams were abandoned, while others have been relocated with a impresive dynamic at historical time scal

Climate Sensitivity of the Arid Scrublands on the Tibetan Plateau Mediated by Plant Nutrient Traits and Soil Nutrient Availability

Climate models predict the further intensification of global warming in the future. Drylands, as one of the most fragile ecosystems, are vulnerable to changes in temperature, precipitation, and drought extremes. However, it is still unclear how plant traits interact with soil properties to regulate drylands’ responses to seasonal and interannual climate change. The vegetation sensitivity index (VSI) of desert scrubs in the Qaidam Basin (NE Tibetan Plateau) was assessed by summarizing the relative contributions of temperature (SGST), precipitation (SGSP), and drought (temperature vegetation dryness index, STVDI) to the dynamics of the normalized difference vegetation index (NDVI) during plant growing months yearly from 2000 to 2015. Nutrient contents, including carbon, nitrogen, phosphorus, and potassium in topsoils and leaves of plants, were measured for seven types of desert scrub communities at 22 sites in the summer of 2016. Multiple linear and structural equation models were used to reveal how leaf and soil nutrient regimes affect desert scrubs’ sensitivity to climate variability. The results showed that total soil nitrogen (STN) and leaf carbon content (LC), respectively, explained 25.9% and 17.0% of the VSI variance across different scrub communities. Structural equation modeling (SEM) revealed that STN and total soil potassium (STK) mediated desert scrub’s VSI indirectly via SGST (with standardized path strength of −0.35 and +0.32, respectively) while LC indirectly via SGST and SGSP (with standardized path strength of −0.31 and −0.19, respectively). Neither soil nor leave nutrient contents alone could explain the VSI variance across different sites, except for the indirect influences of STN and STK via STVDI (−0.18 and 0.16, respectively). Overall, this study disentangled the relative importance of plant nutrient traits and soil nutrient availability in mediating the climatic sensitivity of desert scrubs in the Tibetan Plateau. Integrating soil nutrient availability with plant functional traits together is recommended to better understand the mechanisms behind dryland dynamics under global climate change

What are the Factors affecting Tourist Behavior based on the Perception of Risk? Romanian and Serbian Tourists’ Perspective in the Aftermath of the recent Floods and Wildfires in Greece

During the summer season 2018 and 2019, natural hazards (namely, floods and wildfires) have occurred at some of the most popular tourist destinations in Greece, endangering tourists’ safety and vacation quality. These have influenced tourists’ perception of Greece as a “potentially risky destination”, causing a decrease in the number of tourists willing to visit this country. However, the current study assumes that some tourists will show more courageous travel behavior in the aftermath of natural hazards, while others will remain cautious when deciding to travel to risky destinations. Therefore, the questionnaire on a sample group of 431 respondents from Serbia and Romania was conducted to explore the factors influencing such differences. The study aims to explore whether tourists’ individual characteristics influence tourism worries and tourist behavior based on perceived risks. The study also intends to analyze the moderating role of tourists’ nationality, considering the relationship between personality and tourist behavior based on the perceived risk. The findings provide evidence that not only tourists’ personality but also sociodemographic characteristics influence tourism worries and tourist behavior based on the perceived risk. Additionally, the study is the first to explore and confirm the role of nationality in tourist behavior based on the perceived risk, as well as the moderation role of nationality in regression between tourist’s personality and behavior based on the perception of risk. Theoretical and practical implications are discussed in the paper

Évaluation des risques de glissement de terrain par la méthode de la régression logistique: Application à deux zones basses de Roumanie

International audienceLandslide susceptibility constitutes an important component within the landslide risk equation and therefore, itsassessment is very useful for improving the prognosis of such phenomena. The present research aims to assess landslide susceptibilityfor two low hills regions from Romania, situated in different geographical conditions. The application of the logisticregression method aimed to reveal the relations among the factors controlling the landslides’ manifestation and their spatialdistribution. The computer aided data processing in GIS environment points out the slope and land use as the most importantcausal factors for landsliding, followed by terrain aspect, distance from drainage network and precipitations. Landslide susceptibilitymaps were achieved for both study regions. The validity of the prediction model was checked using the ROC curve(Receiver Operating Characteristic) and the AUC (Area Under the Curve) respectively, which reveal a high accuracy degree.Cet article propose l’évaluation de la susceptibilité aux glissements de terrain dans deux secteurs de collinesbasses de Roumanie. Par l’application de la méthode de régression logistique, on se propose de saisir les relations entreles facteurs responsables de l’occurence des glissements de terrain et leur distribution spatiale. Le traitement automatiquedes données par SIG prend en compte la pente, la nature géologique du terrain, l’exposition des versants, ladistance par rapport au réseau de drainage et les précipitations annuelles. On obtient ainsi deux cartes de susceptibilitéaux glissements. La validité du modèle de prédiction a été vérifié à l’aide de la courbe ROC (Receiver Operating Characteristic),respectivement pour l’aire AUC située sous la courbe (Area Under the Curve), en mettant en évidence un degréélevé de prédiction.Cet article propose l’évaluation de la susceptibilité aux glissements de terrain dans deux secteurs de collinesbasses de Roumanie. Par l’application de la méthode de régression logistique, on se propose de saisir les relations entreles facteurs responsables de l’occurence des glissements de terrain et leur distribution spatiale. Le traitement automatiquedes données par SIG prend en compte la pente, la nature géologique du terrain, l’exposition des versants, ladistance par rapport au réseau de drainage et les précipitations annuelles. On obtient ainsi deux cartes de susceptibilitéaux glissements. La validité du modèle de prédiction a été vérifié à l’aide de la courbe ROC (Receiver Operating Characteristic),respectivement pour l’aire AUC située sous la courbe (Area Under the Curve), en mettant en évidence un degréélevé de prédiction

Climate Sensitivity of the Arid Scrublands on the Tibetan Plateau Mediated by Plant Nutrient Traits and Soil Nutrient Availability

Climate models predict the further intensification of global warming in the future. Drylands, as one of the most fragile ecosystems, are vulnerable to changes in temperature, precipitation, and drought extremes. However, it is still unclear how plant traits interact with soil properties to regulate drylands’ responses to seasonal and interannual climate change. The vegetation sensitivity index (VSI) of desert scrubs in the Qaidam Basin (NE Tibetan Plateau) was assessed by summarizing the relative contributions of temperature (SGST), precipitation (SGSP), and drought (temperature vegetation dryness index, STVDI) to the dynamics of the normalized difference vegetation index (NDVI) during plant growing months yearly from 2000 to 2015. Nutrient contents, including carbon, nitrogen, phosphorus, and potassium in topsoils and leaves of plants, were measured for seven types of desert scrub communities at 22 sites in the summer of 2016. Multiple linear and structural equation models were used to reveal how leaf and soil nutrient regimes affect desert scrubs’ sensitivity to climate variability. The results showed that total soil nitrogen (STN) and leaf carbon content (LC), respectively, explained 25.9% and 17.0% of the VSI variance across different scrub communities. Structural equation modeling (SEM) revealed that STN and total soil potassium (STK) mediated desert scrub’s VSI indirectly via SGST (with standardized path strength of −0.35 and +0.32, respectively) while LC indirectly via SGST and SGSP (with standardized path strength of −0.31 and −0.19, respectively). Neither soil nor leave nutrient contents alone could explain the VSI variance across different sites, except for the indirect influences of STN and STK via STVDI (−0.18 and 0.16, respectively). Overall, this study disentangled the relative importance of plant nutrient traits and soil nutrient availability in mediating the climatic sensitivity of desert scrubs in the Tibetan Plateau. Integrating soil nutrient availability with plant functional traits together is recommended to better understand the mechanisms behind dryland dynamics under global climate change

DataSheet_1_Climate overrides fencing and soil mineral nutrients to affect plant diversity and biomass of alpine grasslands across North Tibet.docx

IntroductionOvergrazing and warming are thought to be responsible for the loss of species diversity, declined ecosystem productivity and soil nutrient availability of degraded grasslands on the Tibetan Plateau. Mineral elements in soils critically regulate plant individual’s growth, performance, reproduction, and survival. However, it is still unclear whether plant species diversity and biomass production can be improved indirectly via the recovery of mineral element availability at topsoils of degraded grasslands, via grazing exclusion by fencing for years.MethodsTo answer this question, we measured plant species richness, Shannow-Wiener index, aboveground biomass, and mineral element contents of Ca, Cu, Fe, Mg, Mn, Zn, K and P at the top-layer (0 - 10 cm) soils at 15 pairs of fenced vs grazed matched sites from alpine meadows (n = 5), alpine steppes (n = 6), and desert-steppes (n = 4) across North Tibet.ResultsOur results showed that fencing only reduced the Shannon-Wiener index of alpine meadows, and did not alter aboveground biomass, species richness, and soil mineral contents within each grassland type, compared to adjacent open sites grazed by domestic livestock. Aboveground biomass first decreased and then increased along with the gradient of increasing Ca content but did not show any clear relationship with other mineral elements across the three different alpine grassland types. More than 45% of the variance in plant diversity indices and aboveground biomass across North Tibet can be explained by the sum precipitation during plant growing months. Structural equation modelling also confirmed that climatic variables could regulate biomass production directly and indirectly via soil mineral element (Ca) and plant diversity indices.DiscussionOverall, the community structure and biomass production of alpine grasslands across North Tibet was weakly affected by fencing, compared to the robst climatic control. Therefore, medium-term livestock exclusion by fencing might have limited contribution to the recovery of ecosystem structure and functions of degraded alpine grasslands.</p

National-scale landslide susceptibility map of Romania in a European methodological framework

International audienc