The Holocene paleoenvironmental history of Western Caucasus (Russia) reconstructed by multi-proxy analysis of the continuous sediment sequence from Lake Khuko

The Holocene ◽  
2020 ◽  
pp. 095968362097278
Author(s):  
Alexei M Grachev ◽  
Elena Y Novenko ◽  
Evgeniy A Grabenko ◽  
Mikhail Y Alexandrin ◽  
Elya P Zazovskaya ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Susceptibility ◽  
Organic Matter ◽  
Sediment Core ◽  
Organic Matter Content ◽  
Matter Content ◽  
Western Caucasus ◽  
Climate History ◽  
The Holocene ◽  
The Western Caucasus

This paper presents new multi-proxy records of the Holocene environmental and climatic changes in the Western Caucasus revealed from a continuous sediment sequence from mountainous Lake Khuko (Caucasus State Natural Biospheric Reserve, 1744 m a.s.l.). Palaeoecological analyses of a sediment core for grain size, magnetic susceptibility, loss on ignition, and pollen allowed us to determine five principal climatic phases with several subphases since 10.5 ka BP. The age model is based on seven accelerator mass spectrometry 14C dates, supplemented by 210Pb data for the uppermost part of the sediment core. Warm periods (10.5–6.7, 6.7–5.5, 3.5–2.4, 0.8–0.5 ka BP) were characterized by high biological productivity in the lake as indicated by high organic matter content and expansion of forests, typical of modern low and middle mountain zones, as indicated by the increase in abundance of Quercus, Ulmus, Corylus, and Tilia in the pollen assemblages. Cold periods (5.5–3.5, 2.4–0.8, and 0.5 ka BP–present) are marked by a consistent decrease in organic matter content in lake deposits and possibly higher intensity of the catchment erosion. The changes in pollen assemblages (for instance peaks of Abies, Picea, and Pinus) suggested a potential elevational decline in the boundaries of vegetation belts and expansion of high-altitude woodlands. Abrupt changes in the lake ecosystem were identified between 4.2 and 3.5 ka cal BP marked by a short-term variation in sediment regime shown by variation in organic matter content, magnetic susceptibility values, and sediment grain size. This was probably caused by climatic fluctuations in the Western Caucasus region as a result of complex shifts in the ocean-atmosphere system during the 4.2 ka event. Overall, the first Holocene multi-proxy continuous lake sediment record provides new insights into the climate history in the Western Caucasus.

scholarly journals Superficial sediments and their relation to polyehaete families in a subtropieal embayment, Mexico

2015 ◽  
pp. 237-238
Author(s):  
Nuria Méndez ◽  
María Green Ruiz
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Fine Sand ◽  
Matter Content ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Superficial Sediments ◽  
Soft Bottoms

The soft bottoms in front of Mazatlan Bay and "Isla de la Piedra" Peninsula were studied to produce maps (depth, grain size and organic matter content in sediments). Sixty samples were óbtained with a 30 x 30 van Veen grab (4-21 m depth) and polychaetes were extracted from 21 subsamples. Grain size ranged from -1.05 phi (gravel) to 3 .81 phi (very fine sand), with fme sand predominl\ting. Organic matter content in sediment was 0.91-3.06 % (most values = 1-2 %). Thirty polychaete families (905 individuals/m2 in mean) were found, and Cirratulidae, Spionidae, Onuphidae, and Pilargiidae were domiuant. Pearson's correlation of grain size.

scholarly journals Variability of macrofauna distribution along a dissipative log-spiral sandy beach in Rio de Janeiro, Southeastern Brazil

2017 ◽  
Vol 81 (1) ◽  
pp. 111 ◽  
Author(s):  
Carlos A.M. Barboza ◽  
Tatiana Cabrini ◽  
Gustavo Mattos ◽  
Viviane Skinner ◽  
Ricardo Cardoso
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Community Structure ◽  
Organic Matter Content ◽  
Principal Component ◽  
Matter Content ◽  
Southeastern Brazil ◽  
Individual Species ◽  
Beach Slope ◽  
Sediment Sorting

Log-spiral beaches display defined physical gradients alongshore. However, the majority of studies focus on the variability of a single population of macrofauna species. We aimed to investigate the variation in species distribution and in community structure along ten transects on a log-spiral beach. Principal component analysis indicated a clear physical gradient alongshore. Redundancy analysis showed that the sheltered end was related to smaller particle sizes, higher organic matter content and high densities of polychaetes. The exposed end was characterized by coarser sand, lower organic matter content and a high presence of crustaceans. Model selection indicated that the “best fit” to explain the variability in the number of individuals included grain size and beach slope. Variability of the polychaete Scolelepis squamata was best explained by grain size, slope and sediment sorting. The best model for the cirolanid Excirolana armata only included sediment sorting. The physical gradient in sediment texture and the beach slope explained more than one-third of the variability in community structure. The physical variables were also correlated with the distribution of the individual species. We showed that the physical gradient on log-spiral coasts may be an important driver of macrofauna variability, even at mesoscales and in dissipative conditions.

Impact of lightning on organic matter-rich soils: influence of soil grain size and organic matter content on underground fires

2007 ◽  
Vol 45 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Vittorio Zanon ◽  
Fátima Viveiros ◽  
Catarina Silva ◽  
Ana Rita Hipólito ◽  
Teresa Ferreira
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Grain Size

scholarly journals The Effect of Stormwater Discharge on the Nearshore Benthic Environment of Inner Wellington Harbour

2021 ◽  
Author(s):  
◽  
Lesley Anne Bolton-Ritchie
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Control Site ◽  
Matter Content ◽  
Sediment Grain Size ◽  
Metal Concentrations ◽  
Biological Community ◽  
Benthic Environment ◽  
Over Time

<p>To investigate the spatial and temporal effects of stormwater discharge on the nearshore benthic environment of inner Wellington Harbour, sediment grain size, organic matter content, concentrations of As, Cr, Cu, Ni, Pb and Zn and the presence and abundance of the benthic macrobiota were measured at a number of stations at both stormwater outlets and at control sites. Correlations between the biological and the sedimentological and chemical variables were also investigated. In the vicinity of some outlets the sediment grain size distribution was altered and the sediment organic matter content was up to 5.5 times higher and metal concentrations were up to 11 times higher, than that at control sites. In general organic matter content and metal concentrations were highest close to an outlet and decreased with increasing distance seaward. With increasing distance from outlets the biological communities changed and there were significant differences in one or more of total, polychaete, arthropod and mollusc taxa, polychaete and mollusc individuals, diversity and the abundance of 12 taxa. The spatial extent of the impact of stormwater discharge on the benthic environment ranged from l0 to more than 45 metres from an outlet. Over time the largest range in organic matter content at an outlet was 6.1-42.8% while at a control it was 4-9%. For As, Cu, Pb and Zn the range in concentration over time was larger at stations closer to than those further from the outlet and larger at outlet than control site stations e.g. at 2 m in front of one outlet the Pb concentration range was 25l-1367 ppm, at 20 m from the outlet it was 15-22 ppm and at the associated control site 2 m station it was 15-20 ppm. Over time the direction of change in the biological community was different, and there were significant differences in the number of total, mollusc, polychaete and arthropod taxa and individuals and diversity, between that at the outlet and the associated control site. 27 taxa were more abundant at outlet than control sites and 45 taxa were more abundant at control than outlet sites over time. The biological community at outlet and control sites was best correlated to combinations of 2-5 of the sedimentological/chemical variables. Of these variables, organic matter content was the only commonly occurring variable at outlet sites and did not occur as one of the variables at the control sites. Where the organic matter content was >22% there were a low number of taxa and individuals, and with an increase in organic matter content there was a significant decrease in the number of total and arthropod taxa. The abundance of two taxa was significantly correlated to organic matter content and the abundance of six taxa was significantly correlated to metal concentrations.</p>

scholarly journals Late Quaternary palaeoenvironmental reconstruction from Lakes Ohrid and Prespa (Macedonia/Albania border) using stable isotopes

2010 ◽  
Vol 7 (3) ◽  
pp. 3815-3853 ◽  
Author(s):  
M. J. Leng ◽  
I. Baneschi ◽  
G. Zanchetta ◽  
C. N. Jex ◽  
B. Wagner ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Early Holocene ◽  
Lake Levels ◽  
Lake Ohrid ◽  
The Holocene ◽  
Lake Prespa ◽  
Isotope Data ◽  
The Mediterranean

Abstract. Here we present stable isotope data from three sediment records from lakes that lie along the Macedonian-Albanian border (Lake Prespa: 1 core, and Lake Ohrid: 2 cores). The records only overlap for the last 40 kyr, although the longest record contains the MIS 5/6 transition (Lake Ohrid). The sedimentary characteristics of both lakes differ significantly between the glacial and interglacial phases. At the end of MIS 6 Lake Ohrid's water level was low (high δ18Ocalcite) and, although productivity was increasing (high calcite content), the carbon supply was mainly from inorganic catchment rock sources (high δ13Ccarb). During the last interglacial, calcite and TOC production and preservation increased, progressively lower δ18Ocalcite suggest increase in humidity and lake levels till around 115 ka. During ca. 80 ka to 11 ka the lake records suggest cold conditions as indicated by negligible calcite precipitation and low organic matter content. In Lake Ohrid δ13Corg are complacent, in contrast Lake Prespa shows consistently higher δ13Corg suggesting a low oxidation of 13C-depleted organic matter in agreement with a general deterioration of climate conditions during the glacial. From 15 ka to the onset of the Holocene, calcite and TOC begin to increase, suggesting lake levels were probably low (high δ18Ocalcite). In the Holocene (11 ka to present) enhanced productivity is manifested by high calcite and organic matter content. All three cores show an early Holocene characterised by low δ18Ocalcite, apart from the very early Holocene phase in Prespa where the lowest δ18Ocalcite occurs at ca. 7.5 ka, suggesting a phase of higher lake level only in (the more sensitive) Lake Prespa. From 6 ka δ18Ocalcite suggest progressive aridification, in agreement with many other records in the Mediterranean, although the uppermost sediments in one core records low δ18Ocalcite which we interpret as a result of human activity. Overall, the isotope data present here confirm that these two big lakes have captured the large scale, low frequency palaeoclimate variation that is seen in Mediterranean lakes, although in detail there is much palaeoclimate information that could be gained, especially small scale, high frequency differences between this region and the Mediterranean.

scholarly journals Hubungan antara Jenis Sedimen Pasir dan Kandungan Bahan Organik di Pantai Kartini, Jepara, Jawa Tengah

2020 ◽  
Vol 9 (4) ◽  
pp. 423-430
Author(s):  
Gadisza Asmara Yudha ◽  
Chrisna Adhi Suryono ◽  
Adi Santoso
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Data Collection ◽  
Sediment Cores ◽  
Organic Matter Content ◽  
Matter Content ◽  
Primary Data ◽  
Sediment Type ◽  
Sediment Samples ◽  
Community Activities

Pantai Kartini merupakan salah satu kawasan wisata di Kabupaten Jepara. Berbagai aktifitas masyarakat serta infrastruktur perairan menjadi kebutuhan yang sangat krusial dengan letak Pantai Kartini. Adanya aktivitas dan bangunan dapat menyebabkan perubahan sebaran ukuran butir dan kandungan bahan organik. Penelitian ini memiliki tujuan untuk mengetahui jenis dan klasifikasi sedimen serta jumlah kandungan bahan organik yang terdapat dalam sedimen di Pantai Kartini, Jepara. Pengambilan data pada penelitian ini yaitu pengambilan data primer yang berupa sampel sedimen dengan menggunakan sediment core. Dilanjutkan dengan analisis sampel sedimen dan analisis kandungan bahan organik. Hasil penelitian menunjukkan bahwa di perairan Pantai Kartini, Jepara memiliki jenis sedimen pasir (sand) dimana nilai ukuran butir tersebut berkisar dari 81-96%, yang mana pada Stasiun 1 rata-rata sebesar 91,6-96%, Stasiun 2 rata-rata sebesar 93,5-96,9%, dan Stasiun 3 rata-rata sebesar 81,4-92,9%. Sedangkan, Kandungan Bahan Organik yang terdapat di perairan tersebut memiliki konsentrasi berkisar dari 5-14% yang termasuk dalam kriteria rendah-sedang, dimana pada Stasiun 1 rata-rata sebesar 10,9-13,3%, Stasiun 2 rata-rata sebesar 5,92-10,18%, dan Stasiun 3 rata-rata sebesar 7,7-14%. Kartini Beach is one of the tourist areas in Jepara Regency. Various community activities and water infrastructure have become crucial needs in Kartini Beach. The existence of activities and buildings can cause changes in the distribution of grain size and content of organic matter. This study aims to determine the type and classification of sediments and the amount of organic matter content contained in sediments in Kartini Beach, Jepara. Data collection in this study is primary data collection in the form of sediment samples using sediment cores. Followed by analysis of sediment samples and analysis of organic matter content. The results showed that in Kartini Coast waters, Jepara had a sand sediment type where the grain size values ranged from 81-96%, which at Station 1 averaged 91,6-96%, Station 2 on average amounted to 93,5-96,9%, and Station 3 averaged 81,4-92,9%. Meanwhile, the content of organic matter contained in these waters has concentrations ranging from 5-14% which are included in the criteria of low-moderate, where at Station 1 an average of 10,9-13,3%, Station 2 an average of 5,92-10,18%, and Station 3 averaging 7,7-14%. 

scholarly journals Application of multi-step approach for comprehensive identification of microplastic particles in diverse sediment samples

2020 ◽  
Author(s):  
Olga Konechnaya ◽  
Christina Schwanen ◽  
Jan Schwarzbauer
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Cost Effective ◽  
Matter Content ◽  
Sediment Samples ◽  
Pollution Levels ◽  
Remediation Strategies ◽  
Cost Effective Method ◽  
Contamination Levels

Abstract The tremendous increase of plastic production, its intensive usage in packaging, as transport material and the insufficient management of plastic garbage lead to a rise of microplastic particles as anthropogenic contaminant in our environment. To develop appropriate management and remediation strategies for this global pollution problem, reliable and consistent analytical procedures for measuring plastics in the complex matrices need to be designed. The applicability of an easy, robust and fast multi-step approach was tested on three sediment samples from riverine, beach and backwater areas of varying origin, grain size and organic matter content is reported here. The optimized method included grain size fractionation, density separation and μ-FTIR analyses. Identification was based on two complementary methods of μ -FTIR measurements, the Image mode for small microplastics (&lt;1 mm) and the ATR method for bigger (1–5 mm) particles. The analyses revealed the identification of several polymers in various grain sizes at different pollution levels. Major findings are the dominance of PET particles and the highest frequency of microplastic particles in the midsize fraction of 100–500 μm. Generally, the method was able to reliably detect microplastic particles in several grain size fractions and down to very low contamination levels of approximately. ten particles per 50 g of sediments with different organic matter content and various grain size characteristics. Moreover, the presented multi-step approach represents a fast, easy and less cost-effective method as alternative to more expensive and time-consuming methods.

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