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The upper reaches of the Yellow River in China, influenced by erosion of the Yellow River and tectonic activities, are prone to landslides. Therefore, it is necessary to investigate the existing landslide traces. Based on visual interpretation on high-resolution satellite images and terrain data, supplemented and validated by existing landslide records, this paper prepared the most complete and detailed landslide traces inventory in Jianzha County, Huangnan Tibetan Autonomous Prefecture, Qinghai Province, to date. The results indicate that within the study area of 1714 km², there are at least 713 landslide traces, ranging in scale from 3,556 m2 to 11.13 km², with a total area of 134.46 km². The total landslide area excluding the overlap area is 126.30 km². The overall landslide point density and area density in the study area are 0.42 km[sup -2] and 7.37% respectively. The maximum point density and maximum area density of landslide traces in the area are as high as 5.69 km-2 and 98.0% respectively. The landslides are primarily distributed in the relatively low-elevation northeastern part of Jianzha County, characterized mainly by large-scale loess landslides, with 14 landslides exceeding 1x10[sup 6] m². This inventory not only supplements the landslide trace data in the transition zone between the Qinghai-Tibet Plateau and the Loess Plateau, but also provides an important basis for subsequent landslide risk zoning, response to climate change, and landscape evolution. Additionally, it holds significant reference value for compiling landslide inventories in similar geological environments. [ABSTRACT FROM AUTHOR]

The Grain for Green Project (GGP) has considerably improved the vegetation cover of the Loess Plateau, as well as changed the carbon and water coupling process of local vegetation to a certain extent. Water use efficiency (WUE) is a crucial measure for evaluating ecosystem responses to global climate change and is a key indicator of the carbon–water coupling between terrestrial ecosystems and the environment. A comprehensive understanding of the impact of vegetation reconstruction on WUE on the Loess Plateau is of great significance to the vegetation growth and contribution to sustainable of the Loess Plateau. In recent years, scholars have gained a more comprehensive understanding of the distribution and drivers of WUE on the Loess Plateau. However, through the study of carbon and water coupling in the Loess Plateau, it is found that the effects of different vegetation restoration levels on WUE are still to be studied in depth in terms of spatial and temporal heterogeneity and long timeseries. In this paper, we analyzed the trends of Normalized Difference vegetation cover (NDVI) and WUE from 2001 to 2010 and 2011 to 2020, respectively, to research at the WUE of the vegetation in this area in relation to vegetation restoration. It was found that the Loess Plateau's vegetation WUE rose from 2001 to 2020 at a rate of 0.023 g C kg−1 H2O per year, and that the increase from 2011 to 2020 was more significant than the growth from 2000 to 2010. The Loess Plateau's area with a growing trend in vegetation water use rate increased from 77.12% in 2001–2010 to 88.63% in 2011–2020, with the majority of the increased area occurring in the northeastern Inner Mongolia region. After 20 years of the reforestation project, the area where NDVI and WUE increased simultaneously accounted for 71.54% of the Loess Plateau, the area where NDVI increased but WUE decreased accounted for 10.95% of the Loess Plateau, and the area where NDVI increased but WUE decreased accounted for 7.15% of the Loess Plateau. The correlation between temperature precipitation and WUE was not significant for the whole Loess Plateau, further indicating that the increase in vegetation cover was the main reason for the increase in vegetation water efficiency. Therefore, the effect of vegetation cover on WUE should be fully considered when vegetation restoration is carried out on the Loess Plateau. [ABSTRACT FROM AUTHOR]

Long-term continuous deposits and well-preserved thick loess sections are natural archives for the reconstruction of global climate change. However, the loess sections are often discontinuous owing to soil erosions and accumulations. This study aimed at reconstructing long-term continuous paleoclimatic records by integrating the target sections of two typical loess sequences in northeast (NE) China. One section, the Dajiugang (DJG) section, was investigated and sampled, and the Sanbahuo (SBH) section was used as the target for integrating and reconstructing the paleoclimate. Sedimentary, pedogenesis, and luminescence dating analyses were conducted to analyze the potentials for reconstructing the paleoclimate by integrating two typical loess sections. The results indicated that the paleoclimate records derived from the DJG section can be used to reconstruct the continuous paleoclimate of NE China by integrating them with the SBH section. The paleoclimate information inferred from the DJG section could impute paleoclimate data from 71 to 11.7 ka, which were missing in the SBH section. The paleoclimate of NE China generally consisted of three periods from 71 to 11.7 ka: cold and dry from 29 to 11.7 ka, alternately cold and warm from 57 to 29 ka, and warm and wet to cold and dry from 71 to 57 ka. Integrating the target loess sections can contribute to reconstructing regional long-term continuous paleoclimate records where discontinuous loess sequences occurred. [ABSTRACT FROM AUTHOR]

The Loess Plateau of China, located to the west of the Liupan Mountains and north of the Qinling Mountains stretching across the Yellow River, is the main loess deposit area in Northwest China. The loess in the northwest of China has deposits with large thickness and extensive distribution. Scanning electron microscopy (SEM) and energy spectrum analysis of loess have been performed to study the relationship between the loess microstructures and the forming climates Era. The relevant indexes were evaluated including the sand‐dropping speed (Vn), certain sedimentary depths (hn sand particle volume (Vd) and element ratios of Ca/Fe, K/Al, Si/Al and Ca/Mg. The microstructure indexes of loess accumulation and evolution reflect paleoclimate conditions and time scales to a certain extent. The important discovery is the microscopic sand‐dropping speed (Vn) and the sedimentary depth hn) calculation method of different sedimentary ages. These indices are compared with the record of major aeolian‐forming climates from the Guliya ice core, and provide a reliable benchmark for studying climate change It also can be used as important indicators of monsoonal change and environmental evolution reconstruction. The index of sand sedimentation speed (Vn) got from loess microstructure could reflect sand‐dropping speed and loess deposition course. According the article can serve as new indicators of climatic changes of different forming loess layers. It can also be concluded that the climatic indexes obtained from loess microstructure can reflect climate conditions of loess forming. The loess forming climatic parameters are synchronous correspond to Tengger Desert and Guliya ice core for studying climate change, then microscopic parameters can also be used for preliminary analysis of loess climate formation and has be found corresponding evidence, and the loess climatic parameters correspond to the other two indexes. The analysis of loess microstructure indexes is very useful in researching climate change. Loess microstructure indexes can find new indicators and information about the monsoon climate evolution and paleoclimate changes. [ABSTRACT FROM AUTHOR]

Background and Objectives: During the Quaternary period mid to high-altitude areas were affected by loess deposition. In Iran's northern and northeastern regions, significant loess deposits are prevalent and distributed throughout the Iranian Loess Plateau and along the northern foothills of the Alborz Mountains. Intercalated within these loess deposits are paleosols, formed during warm and moist climatic conditions (interglacial period). These paleosols offer an opportunity to study the climatic and environmental changes that occurred during the Quaternary period. Understanding the relationship between loess deposition and paleosol formation can offer significant insights into the mechanisms that drive changes in global climate and how they affect the Earth's geology and ecosystems. Studies have shown that loess sediments and loess-derived soils contain different concentrations of iron minerals such as hematite, iron oxyhydroxide, and goethite. These minerals are highly sensitive to environmental changes, and evaluating the changes of these minerals in loess-paleosol sequences can be a valuable indicator for studying paleoenvironmental changes. The two main minerals that cause color and magnetic susceptibility changes in loess-paleosol sequences are goethite and hematite. Therefore, the assessment of loess-paleosol sequences from the aspect of magnetic and colorimetric parameters provides the possibility to identify paleoenvironmental and climatic changes. The main goal of this research is to investigate the changes in iron oxides in the loess-paleosol sequence in the east of Golestan province using colorimetric techniques and temperature-dependent magnetic susceptibility in order to provide enough information for reconstructing the paleoclimatic conditions during the formation of paleosols. Materials and Methods: Sampling was performed from the loess-paleosol sequence in the eastern Golestan province, for each loess and paleosol horizon. Initial colorimetric and magnetic susceptibility measurements were carried out respectively for 1345 and 24 samples at LIAG Institute in Germany. Color measurements were carried out with a spectrophotometer machine that covered the visible light range. The temperature magnetic susceptibility was carried out using in the 20-700 °C temperature range in an argon atmosphere to minimize oxidation. Results and Discussion: According to the results of this study, we can mention the identification of iron minerals in loess and paleosol samples using colorimetric analysis. Iron minerals such as hematite, goethite, and maghemite can be detected at wavelengths 565, 435, and 595 nm, respectively. Colorimetric results showed that the ratio of hematite to goethite of paleosols has increased compared to loess sediments in the study area, which indicates the increase in precipetation and soil moisture during the interglacial period. The heating curve (temperature-dependent magnetic susceptibility) of loess samples at 560-590 degrees Celsius showed a sharp decrease due to magnetite minerals in these samples. At the same time, this happens in paleosols at a temperature of 300-350 degrees Celsius, which is due to the loss of the maghemite mineral formed during the interglacial period. The results showed that the decrease in the heating curve in paleosols indicates the increase in the intensity of soil-forming processes. Conclusion: The results of this study showed that iron minerals such as magnetite, maghemite, hematite, and goethite in loess and paleosols play an important role in magnetic properties and soil color. Also, the increase in the presence of hematite and maghemite in paleosols indicates the increase in the intensity of soil formation processes and humidity during the formation of paleosols. The results of this research showed that the colorimetric technique, along with temperature-dependent magnetic susceptibility, can be one of the fast and accurate methods in studying and identifying paleosols. [ABSTRACT FROM AUTHOR]

Archeological evidence from loess sediments from Shangchen on the southeastern Chinese Loess Plateau indicates a suspension of hominin occupation around the time of the early mid‐Pleistocene climate transition, prompting a re‐assessment of climate‐vegetation‐hominin interactions. Loess deposits with in situ lithic records cover the period of hominin occupation and reveal four distinct climate‐vegetation periods (2.1–1.8, 1.8–1.26, 1.26–0.9, and 0.9–0.6 Ma). Major oscillations in climate superimposed upon an aridification trend and an expansion of C4 herbaceous vegetation from about 1.26 Ma may have driven early humans to move to more hospitable locations in the region. Comparison with the record at Nihewan indicates that large‐scale climate oscillations induced disparate hominin responses due to distinctive local environmental conditions. Plain Language Summary: A combination of several lines of evidence suggests that changes in climate and their impacts on the availability of food and shelter from around 1.26 million years ago may have driven the dispersal of early humans from the southeastern Chinese Loess Plateau to more hospitable environments elsewhere in the region. Key Points: Pleistocene temperature, rainfall, and C4 plants ratios are quantitatively reconstructed from the Shangchen loess deposits with artifactsHigh climate variability, C4 plants expansion and aridification suspended hominin occupation at Shangchen during the early mid‐Pleistocene climate transitionHominins responded differently to large‐scale climate oscillations depending on distinctive local environmental conditions [ABSTRACT FROM AUTHOR]

In this study, the compiled malacological record of the two most important loess–palaeosol sequences (LPS) in Serbia was used to reconstruct the Malacothermometer July Paleotemperature (MTJP) of the last nine glacials. The sieved loess samples yielded shells of 11 terrestrial gastropod species that were used to estimate the MTJP. Veliki Surduk (covering the last three glacial cycles) and Stari Slankamen (covering the last fourth to ninth glacial cycle) LPSs previously lacked the malacological investigations. After the sieving, a total of 66,871 shells were found, from which 48,459 shells were used for the estimation of the MTJP. Through the studied period, the reconstructed MTJP was ranging from 14.4 °C to 21.5 °C. The lowest temperature was recorded during the formation of the loess unit L5, equivalent to the Marine Isotope Stage (MIS) 12. The second-coldest summers were occurring during the MIS 16 glacial. Although the warmest glacial was L8 (MIS 20) according to MTJP, these July temperatures might be overestimated due to only two samples from the poorly preserved L8 unit. The malacological material derived from the loess units at Veliki Surduk and Stari Slankamen LPSs showed great potential for July temperature reconstruction, as the comparison with other regional records showed similar climate changes. Further work is necessary to validate the age scale of the oldest samples, and a higher resolution sampling could lead to more detailed July temperature fluctuations, as was shown for the youngest glacial in this study. Likewise, estimating the July temperature using different proxies (e.g., pollen) from the same LPSs could be used to confirm the observed climate trends. [ABSTRACT FROM AUTHOR]

Throughout Earth's history, dust deposits have been considered sensitive markers of fluctuations in global atmospheric circulation patterns. However, the identification of ancient dust deposits remains problematic, as their massive (structureless) nature impedes an unequivocal classification. In southern Africa, the Lower Jurassic Clarens Formation is dominated by intriguing structureless sandy siltstones that have been interpreted as loess even though classical diagnostic outcrop‐scale loess features are not observed. In this study, we utilized grain characteristics such as size, shape, sorting and fabric to assess the origin of these ubiquitous massive beds, as compared to strata with a known origin in the unit. Based on these grain characteristics, the massive beds can be grouped into six different facies types (Facies 1–6). Facies 1 has very similar grain features to the large‐scale cross‐bedded strata and thus it is interpreted as migrating dune deposits, only apparently massive. The dominant grain size with a large proportion of very fine‐grained sand and the random grain fabric suggests that Facies 2 resulted from sandy dust fall (short‐term suspension), whereas Facies 3 is interpreted as aeolian dust, having features consistent with modern and ancient loess due to its dominant silt grain size and random grain fabric. Features in Facies 4 are undiagnostic and could reflect a range of aeolian processes, although a dominant silt grain size may suggest an overwhelming loess component. Facies 5 and 6 show primary aeolian signatures with the preferred grain orientation being evidence of reworking in an aqueous setting (e.g., lake, stream). These six facies types represent a spectrum of depositional processes that occurred in response to erg migration and climatic changes along this Early Jurassic erg margin. Their facies diversity is evidence for: (1) dry and windy conditions in SW Gondwana during the Sinemurian to Pliensbachian, and (2) reworking of the aeolian sediments in various fluvial and lacustrine settings during the development of one of the largest known sand seas in Earth's history. [ABSTRACT FROM AUTHOR]

Whether there are links between geomagnetic field and Earth's orbital parameters remains unclear. Synchronous reconstructions of parallel long-term quantitative geomagnetic field and climate change records are rare. Here, we present 10Be-derived changes of both geomagnetic field and Asian monsoon (AM) rainfall over the last 870 kyr from the Xifeng loess-paleosol sequence on the central Chinese Loess Plateau. The 10BeGM flux (a proxy for geomagnetic field-induced 10Be production rate) reveals 13 consecutive geomagnetic excursions in the Brunhes chron, which are synchronized with the global records, providing key time markers for Chinese loess-paleosol sequences. The 10Be-derived rainfall exhibits distinct ~100 kyr glacial-interglacial cycles, and superimposed precessional (~23 kyr) cycles that match with those in Chinese speleothem d18O record. We find that changes in the geomagnetic field and AM rainfall share a common ~100 kyr cyclicity, implying a likely eccentricity modulation of both the geomagnetic field and climate. [ABSTRACT FROM AUTHOR]

The extent and mechanisms by which precipitation extremes affect hydrological processes in the critical zone (CZ) of loess possessing a thick unsaturated zone remains poorly understood. To this end, we here employed a coupled liquid‒vapor‒heat‒airflow STEMMUS (simultaneous transfer of energy, mass, and momentum in unsaturated soil) model to investigate the impact of extreme precipitation, at both event and annual scales, on CZ hydrological processes within a semiarid loess site vegetated by apple trees on China's Loess Plateau. At the event scale, the vapor flux was two orders of magnitude lower than the liquid water flux. However, the thermal vapor flux penetrated to depths of 200 cm, whereas the isothermal liquid water flux only infiltrated to 100 cm during the study period, implying that thermal‐gradient‐driven vapor transfer is an important mechanism for deep‐layer recharge (DLR). At the annual scale, the DLR below 200 cm during extremely wet years was 6.5 times larger than that during extremely dry years. In contrast, extreme changes in climate had only limited impacts on evapotranspiration; the difference between extremely wet and extremely dry years averaged only 35 mm, much less than the difference in precipitation, which averaged 310 mm. However, the extremely dry years showed a higher ratio (0.58) between transpiration and evapotranspiration than did the extremely wet years (0.51). The findings reported here improve our understanding of CZ hydrological processes related to precipitation extremes in semiarid loess regions. Key Points: Thermal‐gradient‐driven vapor transfer is an important mechanism for deep‐layer recharge (DLR) in loessThe DLR below 200 cm during extremely wet years was 6.5 times larger than that during extremely dry yearsExtreme changes in precipitation had only limited impacts on evapotranspiration [ABSTRACT FROM AUTHOR]

Numerous loess/paleosol sequences (LPS) in the Carpathian Basin span the period of Marine Isotope Stage (MIS) 2 and the last glacial maximum (LGM). Nevertheless, only two known records—Madaras and Dunaszekcső—preserve highly resolved records with absolute chronologies with minimal uncertainties, which enable the meaningful assessment of feedbacks and short-term climatic fluctuations over this period. The Madaras profile is located at the northern margin fringe of the Bácska loess plateau; Dunaszekcső, located on the Danube to its west, yields a chronology built on over 100 14C dates yet spans only part of MIS 2, missing half of the LGM including its peak. Here, we add to the previously published 14C chronology for Madaras (15 dates) with an additional 17 14C and luminescence ages. Resulting age models built solely on quartz OSL and feldspar pIRIRSL data underestimate the 14C based chronology, which is likely based on inaccuracies related to luminescence signal behavior; we observe age underestimations associated with unusual quartz behavior and significant signal loss, a phenomenon also observed in Serbian and Romanian loess, which may relate to non-sensitized grains from proximal sources. Our new chronology provides higher resolution than hitherto possible, yielding consistent 2 sigma uncertainties of ~150–200 years throughout the entire sequence. Our study indicates that the addition of further dates may not increase the chronological precision significantly. Additionally, the new age model is suitable for tackling centennial-scale changes. The mean sedimentation rate based on our new age-depth model (10.78 ± 2.34 years/cm) is the highest yet recorded in the Carpathian Basin for MIS 2. The resolution of our age model is higher than that for the Greenland NGRIP ice core record. The referred horizons in our profile are all characterized by a drop in accumulation and a higher sand input, the latter most likely deriving from nearby re-exposed sand dunes. [ABSTRACT FROM AUTHOR]

Background: Mycoheterotrophy is a unique survival strategy adapted to dense forests and has attracted biologists' attention for centuries. However, its evolutionary origin and related plastome degradation are poorly understood. The tribe Neottieae contains various nutrition types, i.e., autotrophy, mixotrophy, and mycoheterotrophy. Here, we present a comprehensive phylogenetic analysis of the tribe based on plastome and nuclear ITS data. We inferred the evolutionary shift of nutrition types, constructed the patterns of plastome degradation, and estimated divergence times and ancestral ranges. We also used an integration of molecular dating and ecological niche modeling methods to investigate the disjunction between the Loess Plateau and Changbai Mountains in Diplandrorchis, a mycoheterotrophic genus endemic to China that was included in a molecular phylogenetic study for the first time. Results: Diplandrorchis was imbedded within Neottia and formed a clade with four mycoheterotrophic species. Autotrophy is the ancestral state in Neottieae, mixotrophy independently originated at least five times, and three shifts from mixotrophy to mycoheterotrophy independently occurred. The five mixotrophic lineages possess all plastid genes or lost partial/all ndh genes, whereas each of the three mycoheterotroph lineages has a highly reduced plastome: one lost part of its ndh genes and a few photosynthesis-related genes, and the other two lost almost all ndh, photosynthesis-related, rpo, and atp genes. These three mycoheterotrophic lineages originated at about 26.40 Ma, 25.84 Ma, and 9.22 Ma, respectively. Diplandrorchis had presumably a wide range in the Pliocene and migrated southward in the Pleistocene. Conclusions: The Pleistocene climatic fluctuations and the resultant migration resulted in the Loess Plateau-Changbai Mountains disjunction of Diplandrorchis. In the evolution of mycoheterotrophic lineages, the loss of plastid-encoded genes and plastome degradation are staged and irreversible, constraining mycoheterotrophs to inhabit understories with low light levels. Accordingly, the rise of local forests might have promoted the origin of conditions in which mycoheterotrophy is advantageous. [ABSTRACT FROM AUTHOR]

A multi-disciplinary investigation of loess sections in the southeast and northwest of the Chinese Loess Plateau (CLP) and a sediment core drilled in Zhejiang Province of southeast China was conducted. Discrepancies among grain size distribution, rock magnetic properties, geochemical characteristics and chroma features, and up-section weakening relation between various proxies in the Sanmenxia loess section were found. The results were compared with those of the Baicaoyuan loess section in the northwest of the CLP and the sediment records across the plateau and elsewhere. It was suggested that human impacts began to increase soil erosion on the CLP since the middle Holocene. In addition to the increased soil erosion being decoupled from drying climate after 4 ka, renewed intensification of soil erosion was suggested to occur within the interval of 1.5–2.5 ka as a result of enhanced human activities. The two detected increases in human-induced soil erosion on the CLP are consistent with the human-driven land use changes or human–land interactions at national or regional scales, including the anthropogenic influences on the changes in the sediment load of the Yellow River. In contrast, no human impacts overwhelming hydroclimate control of soil erosion was revealed in the Beihuqiao cores, Zhejiang. The population growth during the past 2400 years showed a relative decreasing trend on CLP and a relative increasing trend in Zhejiang. It is indicated that anthropogenic factors have played a key role in modulating the Earth's surface environment. In particular, ecologically fragile areas, such as the CLP, would be much more susceptible to human disturbance and climate change. The current serious land degradation on the CLP mainly results from the negative feedback between human–land interactions. Regional heterogeneity should be taken into account for sustainable development. [ABSTRACT FROM AUTHOR]

, Fitzsimmons et al. [[1]] investigated a 25 m drill core and a nearby 6 m loess-paleosol section from Schwalbenberg, Germany, a site along the Rhine River, and correlated the sensitivity of quartz/feldspar in variable grain size sediments by luminescence dating. Five manuscripts have been submitted for the Special Issue, covering a wide range of aspects of Quaternary studies, from the luminescence-based chronology of Quaternary loess-paleosol deposits to paleomagnetic and sedimentological studies, and of complex environmental and paleoclimatological studies of Holocene sediment deposits and archaeological sites. After comparing several regional and other European reference sections, the authors concluded that the Brunhes-Matuyama Boundary and the S7 (MIS 19) paleosol which represents it are of particular importance for the chronostratigraphic classification of the Eastern European loess-paleosol sections. [Extracted from the article]