Natural multi-hazard risk perception and educational insights among Geography and Tourism students and graduates amid the Covid-19 pandemic.

Multi-hazard risk perception is an emerging research topic that has been gaining more and more interest since the beginning of the Covid-19 pandemic, due to the unprecedented interactions between the management practices of the pandemic and of other co-occurring natural hazards, and to the compounded impact of these multi-hazards. This paper aims to investigate the specialization and study level-dependent differences concerning multi-hazard risk perception and hazard-related education insights of future potential specialists in natural hazard-induced risk management and tourism reconstruction. These differences were explored by applying a multi-layer questionnaire on 547 Geography and Tourism students and graduates from two universities in Iași City (Romania) and Novi Sad (Serbia), and performing descriptive and differential statistical analyses. The statistically significant differences that emerged refer to estimations of the impact level of the Covid-19 pandemic and of other natural hazards at different spatial scales and on different socio-economic activities, on the training/career of the respondents, and to the hazard-related education improvements. Up to date, none of the papers in the existing literature integrate both the Covid-19 pandemic and the co-occurrent natural hazards as objects of students' perception, which makes the present study a starting point for such research endeavours.

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

Introduction: Overgrazing 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. Methods: To 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. Results: Our 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. Discussion: Overall, 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.

Disentangling climatic and anthropogenic contributions to nonlinear dynamics of alpine grassland productivity on the Qinghai-Tibetan Plateau.

Alpine grasslands on the Qinghai-Tibetan Plateau are sensitive and vulnerable to climate change and human activities. Climate warming and overgrazing have already caused degradation in a large fraction of alpine grasslands on this plateau. However, it remains unclear how human activities (mainly livestock grazing) regulates vegetation dynamics under climate change. Here, alpine grassland productivity (substituted with the normalized difference vegetation index, NDVI) is hypothesized to vary in a nonlinear trajectory to follow climate fluctuations and human disturbances. With generalized additive mixed modelling (GAMM) and residual-trend (RESTREND) analysis together, both magnitude and direction of climatic (in terms of temperature, precipitation, and radiation) and anthropogenic impacts on NDVI variation were examined across alpine meadows, steppes, and desert-steppes on the Qinghai-Tibetan Plateau. The results revealed that accelerating warming and greening, respectively, took place in 76.2% and 78.8% of alpine grasslands on the Qinghai-Tibetan Plateau. The relative importance of temperature, precipitation, and radiation impacts was comparable, between 20.4% and 24.8%, and combined to explain 66.2% of NDVI variance at the pixel scale. The human influence was strengthening and weakening, respectively, in 15.5% and 14.3% of grassland pixels, being slightly larger than any sole climatic variable across the entire plateau. Anthropogenic and climatic factors can be in opposite ways to affect alpine grasslands, even within the same grassland type, likely regulated by plant community assembly and species functional traits. Therefore, the underlying mechanisms of how plant functional diversity regulates nonlinear ecosystem response to climatic and anthropogenic stresses should be carefully explored in the future.

Using archaeological and geomorphological evidence for the establishment of a relative chronology and evolution pattern for Holocene landslides.

Hilly regions around the world are one of the most vulnerable places for inhabitation, where landslides represent a permanent threat for their population. In some particular cases, in the past, due to their topographic features, areas affected by massive landslides served a real opportunity for the location of strategic and fortified settlements. In this study, we have extended a previous approach of correlation between landslides and archaeological heritage, adding 14 new representative case studies of landslided hillforts, a new period with landslided hillforts, and a new typology of relationship (landslided tumuli) for establishing relative chronologies for landslide inventories. The landslide mapping presented here supplements a previous inventory, which now has 1211 landslides, and it is based on the interpretation of high-resolution DEMs, geomorphometric derivatives, remote sensing images, and field validation. For one of the most characteristic sites (Baiceni settlement, Iasi County), we used Electrical Resistivity Tomography (ERT) to assess the geometry of the compound and complex landslides. The current approach allowed us to acquire a more accurate relative chronology of landslide activity during the Holocene and Upper Pleistocene, and more importantly, to establish the pattern of landslides evolution in the Moldavian Plateau, North-Eastern Romania. The relict landslides are Lateglacial and Lower Holocene, the old landslides are post-Holocene Climatic Optimum and pre-Medieval, while the recent landslides are post-Medieval. The landslide magnitude decreased continuously, the new events being retrogressive reactivations of earlier events scarps and landslide bodies (as shown by the ERT data). Further studies on absolute dating will improve the relative chronology. Still, while not all the landslides can be dated, the methodology that we describe can be applied to increase the spatial density of the relative chronology. The presented approach can be used in other regions all over the world to establish the relative age of landslide inventories when archaeological topography can be related to landslide topography.