scholarly journals A Long-Term Record of Quaternary Facies Patterns and Palaeonvironmental Trends from the Po Plain (NE Italy) as Revealed by Bio-Sedimentary Data

Geosciences ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 401
Author(s):  
Veronica Rossi ◽  
Alessandro Amorosi ◽  
Giulia Barbieri ◽  
Stefano Claudio Vaiani ◽  
Matteo Germano ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Middle Pleistocene ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Environmental Response ◽  
Alluvial Deposits ◽  
Po Plain ◽  
Ne Italy ◽  
Coastal Marine

Understanding Quaternary dynamics of delta-coastal plains across multiple glacial-interglacial cycles in the Milankovitch band (~100 kyrs) is crucial to achieve a robust evaluation of possible environmental response to future climate-change scenarios. In this work, we document the long-term bio-sedimentary record of core 204 S16 (~205 m long), which covers a wide portion of the post-MPR (Mid-Pleistocene Revolution) interval, taking advantage of the highly subsiding context of the SE Po Plain (NE Italy). Detailed facies characterization through an integrated sedimentological and meiofauna (benthic foraminifers and ostracods) approach allowed for the identification of a repetitive pattern of alluvial deposits alternating with four fossiliferous, paralic to shallow-marine units (Units 1–4). The transgressive surfaces identified at the base of these units mark major flooding events, forced by Holocene (Unit 4), Late Pleistocene (Unit 3) and Middle Pleistocene (Units 1, 2) interglacials. Distinct stratigraphic patterns typify the Middle Pleistocene interval, which includes coastal-marine (tidal inlet and bay) deposits. In contrast, lagoonal sediments record the maximum marine influence in the Late Pleistocene-Holocene succession. As a whole, the meiofauna tracks a regressive trend, with the deepest conditions recorded by the oldest Unit 1 (MIS 9/11 age?).

Recruitment patterns following a severe drought: long-term compositional shifts in Patagonian forests

2008 ◽  
Vol 38 (12) ◽  
pp. 3002-3010 ◽  
Author(s):  
María L. Suarez ◽  
Thomas Kitzberger
Keyword(s):  
Vegetation Change ◽  
Forest Canopy ◽  
Tree Mortality ◽  
Forest Composition ◽  
Future Climate Change ◽  
Severe Drought ◽  
Climate Change Scenarios ◽  
Recruitment Pattern ◽  
Recruitment Patterns

Severe droughts have the potential of inducing transient shifts in forest canopy composition by altering species-specific adult tree mortality patterns. However, permanent vegetation change will occur only if tree recruitment patterns are also affected. Here, we analyze how a massive mortality event triggered by the 1998–1999 drought affected adult and sapling mortality and recruitment in a mixed Nothofagus dombeyi (Mirb.) Blume – Austrocedrus chilensis (D. Don) Flor. et Boult. forests of northern Patagonia. Comparing drought-induced and tree-fall gaps, we assessed changes in forest composition, microenvironments, and seedling density and survival of both species. Drought-kill disturbance shifted species composition of both canopy and sapling cohorts in favour of A. chilensis. Drought gaps were characterized by a shadier and more xeric environment, affecting the recruitment pattern of N. dombeyi seedlings. The seedling cohort was composed mostly of A. chilensis, and its survival was always higher than that of N. dombeyi. Additionally, A. chilensis seedlings showed higher plasticity than N. dombeyi seedlings, increasing its root to shoot ratios in drought gaps. The results suggest that extreme drought itself is a strong driving force in forest dynamics, with important imprints on forest landscapes. Future climate-change scenarios, projecting an increased in frequency and severity of droughts, alert us about expected long-term compositional shifts in many forest ecosystems.

Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 584-587
Author(s):  
Dongju Zhang ◽  
Huan Xia ◽  
Fahu Chen ◽  
Bo Li ◽  
Viviane Slon ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Amino Acid ◽  
Tibetan Plateau ◽  
Late Pleistocene ◽  
Amino Acid Substitution ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Karst Cave ◽  
Late Middle Pleistocene

A late Middle Pleistocene mandible from Baishiya Karst Cave (BKC) on the Tibetan Plateau has been inferred to be from a Denisovan, an Asian hominin related to Neanderthals, on the basis of an amino acid substitution in its collagen. Here we describe the stratigraphy, chronology, and mitochondrial DNA extracted from the sediments in BKC. We recover Denisovan mitochondrial DNA from sediments deposited ~100 thousand and ~60 thousand years ago (ka) and possibly as recently as ~45 ka. The long-term occupation of BKC by Denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the Tibetan Plateau.

scholarly journals Water Quality Sustainability Evaluation under Uncertainty: A Multi-Scenario Analysis Based on Bayesian Networks

2019 ◽  
Vol 11 (17) ◽  
pp. 4764 ◽  
Author(s):  
Anna Sperotto ◽  
Josè Luis Molina ◽  
Silvia Torresan ◽  
Andrea Critto ◽  
Manuel Pulido-Velazquez ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Bayesian Networks ◽  
Climate Model ◽  
Future Climate Change ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Large Variability ◽  
Nutrient Loadings

With increasing evidence of climate change affecting the quality of water resources, there is the need to assess the potential impacts of future climate change scenarios on water systems to ensure their long-term sustainability. The study assesses the uncertainty in the hydrological responses of the Zero river basin (northern Italy) generated by the adoption of an ensemble of climate projections from 10 different combinations of a global climate model (GCM)–regional climate model (RCM) under two emission scenarios (representative concentration pathways (RCPs) 4.5 and 8.5). Bayesian networks (BNs) are used to analyze the projected changes in nutrient loadings (NO3, NH4, PO4) in mid- (2041–2070) and long-term (2071–2100) periods with respect to the baseline (1983–2012). BN outputs show good confidence that, across considered scenarios and periods, nutrient loadings will increase, especially during autumn and winter seasons. Most models agree in projecting a high probability of an increase in nutrient loadings with respect to current conditions. In summer and spring, instead, the large variability between different GCM–RCM results makes it impossible to identify a univocal direction of change. Results suggest that adaptive water resource planning should be based on multi-model ensemble approaches as they are particularly useful for narrowing the spectrum of plausible impacts and uncertainties on water resources.

TT-MARINE: a new open modular cost-effective board to monitor coastal ecosystems

2020 ◽  
Author(s):  
Viviana Piermattei ◽  
Marco Marcelli ◽  
Valentina Cafaro ◽  
Alice Madonia ◽  
Andrea Terribili ◽  
...  
Keyword(s):  
Climate Change ◽  
New Technologies ◽  
Low Cost ◽  
Marine Ecosystems ◽  
Global Ocean ◽  
Future Climate Change ◽  
Observation System ◽  
Climate Change Scenarios ◽  
Anthropogenic Pressures ◽  
Coastal Marine

<p>The coastal marine system is characterized by multiple uses and it represents a vulnerable area highly subjected to anthropogenic pressures. Coastal marine ecosystems monitoring therefore requires an integrated multidisciplinary approach. The modeling of marine coastal dynamics and processes and the development of new observational technologies are fundamental in order to increase the available amount of data needed for the application of integrated approaches. New technologies and coastal observation networks are therefore a priority of the Global Ocean Observation System (GOOS) and of the Agenda 2030 strategy to improve the sustainable management of marine ecosystems and to contribute to future climate change scenarios. In this context a big effort is carried out by existing observing programs (ARGO, DPCP, GO-SHIP, OceanSITES, SOOP), which focus on open ocean waters and do not cover coastal areas. To do this, a significant reduction in the costs of platforms and instruments is necessary while maintaining sufficient measurement precision and consequently data quality. To face this issue, an Arduino based technology has been developed starting from the Tree-Talker-Cloud Technology (TT-Cloud board), a data acquisition and transmission system to monitor the health of trees and the impacts of climate change. From this technology, a new low-cost board, TT-Marine, has been developed, characterized by a high modularity allowing to manage the sensors by different types of communication protocols: RS232, UART, i2c, RS485; analog sensors can be managed by 16 and 24 bit AD converters. Depending on the characteristics and opportunities of the site, the system can manage LoRa, WiFi, gprs/gsm or cable data transmission systems. The TT-Marine is designed to be used in different modes: autonomous, ship-like as a profiler, on buoys and other measuring platforms.Here we present several operating modalities, with different missions and instrumental configurations.</p>

Alluvial deposits evolution in the Inaouene river valley (Morocco) during late Pleistocene and Holocene epoch.

2021 ◽  
Author(s):  
Mohammed Lghamour ◽  
Lhoucine Karrat ◽  
Vincenzo Picotti ◽  
Irka Hajdas ◽  
Negar Haghipour ◽  
...  
Keyword(s):  
Organic Matter ◽  
Late Pleistocene ◽  
Ion Source ◽  
River Valley ◽  
Middle Pleistocene ◽  
Annual Rainfall ◽  
Carbonate Content ◽  
Alluvial Deposits ◽  
Homogeneous Surface ◽  
Middle Atlas

<p>      The Inaouène wadi is a river located in the northern region of Morocco. Its catchment area covers about 5124 km² with an average altitude of 800 m. The tributaries drain the marly reliefs of the Prerif in the northern side, as well as its southern ones are crossing the liasic carbonate and the Paleozoic crystalline rocks of the last Middle Atlas foothills. This region is characterised by a semi-arid Mediterranean climate influenced by the ocean oscillations, the average annual rainfall records 600 mm with a very significant spatial and interannual irregularity.</p><p>Along the major part of its flow, the Inaouène river has cut its bed between the Prerif and the Middle Atlas belts, by following the foreland corridor that separates them. From a pass (Touaher) that marks the corridor closing, the river valley widens from East to West, forming an alluvial plain with a maximum width of 5 km incised by a meandering and highly sinuous stream.</p><p>      Alluvial deposits in this valley are more developed on the Atlas side than at the Prerif foot; At least five levels representing the vestiges of the Lower and Middle Pleistocene terraces are present in the landscape.</p><p>More recent deposits occupy the valley floor, they constitute a more homogeneous surface showing low terraces abrupts and lateral limits between different sedimentary units. These alluvial deposits correspond to the terminal Pleistocene, middle and upper Holocene epoch. About 30 samples of charcoal and TOC have been selected and analysed using the  AMS 14C dating. Due to the scarcity of organic matter, some of the samples contained less than 0.1 mg of carbon and had to be analysed using the gas ion source (GIS) interface of the MICADAS (Haghipour et al., 2019; Wacker et al.,2013). 12 sections were described in the field and of which 8 sections were analysed regarding grain size, mineralogical composition, carbonate content as well as organic matter in soils and sediments.</p><p>      The analysis results indicate that the late Pleistocene is characterised by a high fluvial activity reflected by the development of braided system river and so coarse material, while fine deposits of floodplains are more abundant during the Holocene.</p><p>……...........</p><p><strong>Haghipour, N., Ausin, B., Usman, M. O., Ishikawa, N., Wacker, L., Welte, C., Ueda, K., and Eglinton, T. I., 2019, Compound-Specific Radiocarbon Analysis by Elemental Analyzer-Accelerator Mass Spectrometry: Precision and Limitations: Analytical Chemistry, v. 91, no. 3, p. 2042-2049.</strong></p><p><strong>Wacker, L., Fahrni, S., Hajdas, I., Molnar, M., Synal, H., Szidat, S., and Zhang, Y., 2013, A versatile gas interface for routine radiocarbon analysis with a gas ion source: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions With Materials and Atoms, v. 294, p. 315-319.</strong></p>

scholarly journals Long-term landscape evolution of the Molise sector of the central-southern Apennines, Italy

2017 ◽  
Vol 68 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Vincenzo Amato ◽  
Pietro P.C. Aucelli ◽  
Vito Bracone ◽  
Massimo Cesarano ◽  
Carmen Maria Rosskopf
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Temporal Distribution ◽  
Structural Data ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Southern Apennines ◽  
Geomorphological Evolution ◽  
Present Setting

AbstractThis paper concerns the reconstruction of the main stages of the long-term landscape evolution of the Molise portion of the central-southern Apennines along a transect divided into three sectors (SW, Central and NE). Analysis mainly focused on geomorphological, stratigraphical and structural data supported by chronological constraints, coming from an overall review of past literature and several studies carried out by the authors of the paper during the last 20 years. The results obtained allowed the elaboration of a conceptual model of the long-term evolution of the Molise sector of the central-southern Apennines. Starting from the Pliocene, the emersion of the Molise area occurred gradually from SW to NE, allowing a polycyclic landscape to evolve under the major controls first of compression then transtensional to extensional tectonics as well as climatic variations. Principal markers of the Quaternary geomorphological evolution of the Molise area are represented by the infill successions of the intermontane tectonic depressions located in its internal, SW sector and by four orders of palaeosurfaces that developed between the Early Pleistocene and the beginning of the Late Pleistocene across the region. These markers testify to the alternation of phases of substantial tectonic stability and uplift whose spatial-temporal distribution could be assessed along the investigated transect. Results highlight that the most important stages of landscape evolution occurred during the Early and Middle Pleistocene. At the beginning of the Late Pleistocene, the Molise sector of the Apennine chain had already reached its present setting and further landscape evolution occurred under the major control of climate and land-use.

scholarly journals Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions

2021 ◽  
Vol 13 (7) ◽  
pp. 3885
Author(s):  
Christos Spyrou ◽  
Michael Loupis ◽  
Νikos Charizopoulos ◽  
Ilektra Apostolidou ◽  
Angeliki Mentzafou ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Maximum Velocity ◽  
Weather Conditions ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Climate Conditions ◽  
The Impact

Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.

Early Pleistocene−to−present paleoclimate archive for the American Southwest from Stoneman Lake, Arizona, USA

2021 ◽  
Author(s):  
Spencer E. Staley ◽  
Peter J. Fawcett ◽  
R. Scott Anderson ◽  
Gonzalo Jiménez-Moreno
Keyword(s):  
Late Pleistocene ◽  
Climate Model ◽  
Volcanic Eruptions ◽  
American Southwest ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Future Climate Change ◽  
Radiocarbon Dates ◽  
Middle And Late Pleistocene ◽  
Natural Climate

Long, continuous records of terrestrial paleoclimate offer insights into natural climate variability and provide context for geomorphological studies, climate model reconstructions, and predictions of future climate change. STL14 is an 80 m lacustrine sediment core that archives paleoenvironmental changes at Stoneman Lake, Coconino County, Arizona, from the early Pleistocene (ca. 1.3 Ma) to present. Full-core sedimentology was analyzed using smear slides and core face observations. Lithofacies strongly correlate with wet bulk density and bulk magnetic susceptibility (MS), and these data resemble a sawtooth pattern characteristic of glacial-interglacial climate cycles. A linkage between deep to shallow lake depth transitions and glacial terminations is supported by an age model that incorporates accelerator mass spectrometry radiocarbon dates and tephrochronology of ashes from the Lava Creek B and multiple Long Valley, California, volcanic eruptions. We correlated middle and late Pleistocene glacial maxima to deep lake deposits defined by well-preserved bedding, increased biosilica, boreal pollen taxa (i.e., Picea), and lower density and MS. Interglacial periods are associated with shallow-water deposits characterized by banded-to-massive siliciclastic material, some authigenic calcite, the alga Phacotus, and higher density and MS. Prior to the marine isotope stage (MIS) 24−22 interval, smaller-amplitude changes in the lake environment suggest milder glacial conditions compared to those of the middle and late Pleistocene. Thus, abrupt intensification of glacial conditions may have occurred ca. 900 ka in the American Southwest, mirroring a global characteristic of the mid-Pleistocene transition. The STL14 record suggests that lake environments throughout the history of this small (3.5 km2), internally drained, basaltic catchment are sensitive to the regional hydrologic balance, which, at orbital time scales, is largely influenced by the northern cryosphere and associated changes in atmospheric circulation. The predominance of quartz in sediment throughout the record indicates significant eolian inputs. Few paleoclimate records from this region extend beyond the last glacial cycle, let alone the middle Pleistocene, making STL14 a valuable resource for studying environmental responses to a range of natural climate states and transitions throughout much of the Quaternary.

scholarly journals Assessment of Ecological and Hydro-Geomorphological Alterations under Climate Change Using SWAT and IAHRIS in the Eo River in Northern Spain

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1745
Author(s):  
Julio Pérez-Sánchez ◽  
Javier Senent-Aparicio ◽  
Carolina Martínez Santa-María ◽  
Adrián López-Ballesteros
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Assessment Tool ◽  
Swat Model ◽  
General Circulation Models ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Efficiency Coefficient ◽  
Northern Spain

Magnitude and temporal variability of streamflow is essential for natural biodiversity and the stability of aquatic environments. In this study, a comparative analysis between historical data (1971–2013) and future climate change scenarios (2010–2039, 2040–2069 and 2070–2099) of the hydrological regime in the Eo river, in the north of Spain, is carried out in order to assess the ecological and hydro-geomorphological risks over the short-, medium- and long-term. The Soil and Water Assessment Tool (SWAT) model was applied on a daily basis to assess climate-induced hydrological changes in the river under five general circulation models and two representative concentration pathways. Statistical results, both in calibration (Nash-Sutcliffe efficiency coefficient (NSE): 0.73, percent bias (PBIAS): 3.52, R2: 0.74) and validation (NSE: 0.62, PBIAS: 6.62, R2: 0.65), are indicative of the SWAT model’s good performance. The ten climate scenarios pointed out a reduction in rainfall (up to −22%) and an increase in temperatures, both maximum (from +1 to +7 °C) and minimum ones (from +1 to +4 °C). Predicted flow rates resulted in an incrementally greater decrease the longer the term is, varying between −5% (in short-term) and −53% (in long-term). The free software IAHRIS (Indicators of Hydrologic Alteration in Rivers) determined that alteration for usual values remains between excellent and good status and from good to moderate in drought values, but flood values showed a deficient regime in most scenarios, which implies an instability of river morphology, a progressive reduction in the section of the river and an advance of aging of riparian habitat, endangering the renewal of the species.

scholarly journals Selecting tree species for climate change integrated forest restoration and management in the Chitwan Annapurna Landscape, Nepal

2020 ◽  
Vol 13 ◽  
pp. 29-46
Author(s):  
Gokarna Jung Thapa ◽  
Eric Wikramanayake
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Forest Restoration ◽  
Climate Adaptation ◽  
Range Shifts ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Government ◽  
Choice Of Species

Climate change will affect forest vegetation communities, and field surveys have already indicated measurable distribution range shifts in some tree species. As forests play an important role in stabilizing steep slopes and provide vital ecological goods and services, the Government of Nepal has been encouraging forest restoration and sustainable management. However, reforestation and afforestation programs should consider the long term survivorship of the trees selected for reforestation to build climate adaptation and resilience. Thus, the choice of species should include species that would be expected to grow within the elevation zone or in the particular habitat under future climate change scenarios. In this analysis, we have assessed the response of 12 important tree species to climate change using the IPCC A2A GHG scenario with GCM-based climate envelopes to provide guidelines and recommendations for climate change-integrated forest restoration and management in the Chitwan-Annapurna Landscape (CHAL). The results indicate that several species could exhibit range shifts due to climate change, with an overall trend for species in the lower elevations to move northwards or further up the slopes within the current area of distributions. Analyses such as this, though not perfect, can help to make critical and informed decisions to support long-term forest restoration programs.

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