Search results for "Plateau"

Effect of soil management on soil erosion on sloping farmland during crop growth stages under a large-scale rainfall simulation experiment

2018

Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on abandoned farmland. However, few studies have investigated runoff and soil loss from sloping farmland during crop growth season. The objective of this study was to investigate the effects of soil management on runoff and soil loss on sloping farmland during crop growth season. We tested different soybean growth stages (i.e., seedling stage (R1), initial blossoming stage (R2), full flowering stage (R3), pod bearing stage (R4), and initial filling stage (R5)) and soil management pract…

Quartz OSL dating of late quaternary Chinese and Serbian loess: A cross Eurasian comparison of dust mass accumulation rates

2019

© 2018 Elsevier Ltd and INQUA. Reconstructing dust Mass Accumulation Rate (MAR) from loess deposits is critical to understanding past atmospheric mineral dust activity and requires accurate independent age models from loess deposits across Europe and Asia. Previous correlations of loess in Europe and China have tended to focus on multi-millennial timescales, with no detailed examination of dust MAR at the two ends of the Eurasian loess belt on shorter, sub-orbital scales. Here we present a detailed quartz optically stimulated luminescence (OSL) chronology from the Serbian Titel Loess Plateau (Veliki Surduk loess core) and the Chinese Loess Plateau (Lingtai section). The luminescence ages pa…

Multistratigraphic records of the Lower Cretaceous (Valanginian–Cenomanian) Puez key area in N. Italy

2016

Abstract We present a stratigraphic investigation of a Hauterivian to Cenomanian hemipelagic succession from Col Puez, in the Dolomites (Southern Alps, northern Italy). A composite section of seven segments was studied with bio-, magneto-, and chemostratigraphy, which enabled detailed and robust age calibration of the Puez succession. It also revealed the paleoceanographic history and helped identify the important global climatic events of that period. The age of the Lower Cretaceous Puez Formation in the Dolomites is refined as late Hauterivian to early Cenomanian. Ammonoids provide a detailed biostratigraphic subdivision that forms the basis for analyses of the faunal distribution and the…

Depositional mechanism of the upper Pliocene-Pleistocene shelf-slope system of the western Malta Plateau (Sicily Channel)

2021

Abstract A high resolution seismic stratigraphic study of the western edge of the Malta Plateau (central Mediterranean Sea) was conducted to reconstruct the depositional mechanisms of the shelf-slope system since the end of the Messinian salinity crisis (MSC; 5.3 Ma). The accurate interpretation of a large grid of variable-resolution seismic reflection profiles (multichannel and Sub Bottom) allows us to identify and map a Plio-Quaternary sedimentary sequence overlying the Messinian evaporites. The stratal pattern of this sequence is the result of a clinoform prograding system that constitutes the internal structure of a sedimentary shelf developed in a ramp about 2° slope with bathymetries …

Spatial structure and β-diversity of phytoplankton in Tibetan Plateau lakes: nestedness or replacement?

2017

Spatial patterns and β-diversity of phytoplankton assemblages depend on the relative importance of species dispersal capacity and species-sorting. Variability in species composition, composed by differences in species richness (nestedness) and/or species replacement, may be caused by niche availability and environmental selection. A field survey was carried out in Tibetan plateau on 38 lakes. Tibetan plateau lakes, located at high elevation, are harsh ecosystems characterized by low temperatures, low available nutrients, high UV amount, and strong salinity gradients. Only well-adapted species can survive in these environments. We therefore hypothesized that environmental filtering was the m…

The Eurasian Modern Pollen Database (EMPD), version 2

2020

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to…

Dwarf shrub vegetation of rock ledges and clefts in the Pamir Alai Mountains (Middle Asia: Tajikistan)

2016

AbstractThe paper presents the results of phytosociological researches on rocky slope vegetation in Tajikistan with the aim to establish a comprehensive syntaxonomical classification system. Field studies were conducted in 2010-2014 in Pamir Alai ranges and Pamirian plateau. Nearly 500 relevés documenting rock and scree vegetation were made according to the Braun-Blanquet method. Numerical analyses of selected 58 relevés representing dwarf shrub vegetation on rock ledges made it possible to distinguish: Ephedro glaucae- Spiraeion baldschuanicae and Ephedrion regeliano-fedtschenkoi alliances, as well as Spiraeetum baldschuanicae, Rhamnetum coriaceae, Pentaphylloidetum parvifoliae and Pentaph…

“Into and Out of” the Qinghai‐Tibet Plateau and the Himalayas: Centers of origin and diversification across five clades of Eurasian montane and alpin…

2020

Abstract Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the Qinghai‐Tibet Plateau (QTP) is considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a one‐way street (“out of” the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested m…

A TWO-COMPONENT MANTLE EXTENDING FROM MT. ETNA TO HYBLEAN PLATEAU (EASTERN SICILY) AS INFERRED BY AN INTEGRATED APPROACH WITH NOBLE GASES, TRACE ELEM…

2012

Do ventilatory parameters influence outcome in patients with severe acute respiratory infection? Secondary analysis of an international, multicentre1…

2021

Purpose: To investigate the possible association between ventilatory settings on the first day of invasive mechanical ventilation (IMV) and mortality in patients admitted to the intensive care unit (ICU) with severe acute respiratory infection (SARI). Materials and methods: In this pre-planned sub-study of a prospective, multicentre observational study, 441 patients with SARI who received controlled IMV during the ICU stay were included in the analysis. Results: ICU and hospital mortality rates were 23.1 and 28.1%, respectively. In multivariable analysis, tidal volume and respiratory rate on the first day of IMV were not associated with an increased risk of death; however, higher driving pr…