scholarly journals Carbon capacity of gray forest soils in the Chechen Republic

2022 ◽  
Vol 42 ◽  
pp. 02006
Author(s):  
Rustam Gakaev

Common areas of research needed to measure soil carbon include: (1) the impact of forest management, (2) the impact of climate change, and (3) the impact of increased carbon dioxide. The organic matter of the soil has a great influence on the productivity of the site due to its effect on the physical (bulk density, water retention capacity), biological (microbial populations) and chemical (cation exchange capacity) properties of soils. Recently, there have also been claims of the benefits of dead wood for forest ecosystems. However, as with all nutrients, too much carbon in the soil can have negative consequences, especially with regard to nitrogen immobilization.

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Karol Fijałkowski ◽  
Rafał Rakoczy ◽  
Anna Żywicka ◽  
Radosław Drozd ◽  
Beata Zielińska ◽  
...  

The aim of the study was to assess the influence of rotating magnetic field (RMF) on the morphology, physicochemical properties, and the water holding capacity of bacterial cellulose (BC) synthetized by Gluconacetobacter xylinus. The cultures of G. xylinus were exposed to RMF of frequency that equals 50 Hz and magnetic induction 34 mT for 3, 5, and 7 days during cultivation at 28°C in the customized RMF exposure system. It was revealed that BC exposed for 3 days to RMF exhibited the highest water retention capacity as compared to the samples exposed for 5 and 7 days. The observation was confirmed for both the control and RMF exposed BC. It was proved that the BC exposed samples showed up to 26% higher water retention capacity as compared to the control samples. These samples also required the highest temperature to release the water molecules. Such findings agreed with the observation via SEM examination which revealed that the structure of BC synthesized for 7 days was more compacted than the sample exposed to RMF for 3 days. Furthermore, the analysis of 2D correlation of Fourier transform infrared spectra demonstrated the impact of RMF exposure on the dynamics of BC microfibers crystallinity formation.


2019 ◽  
Vol 52 (1) ◽  
pp. 43
Author(s):  
Omid Bahmani

<p><strong> </strong>Tillage is one of the most important practices that have a significant influence on the soil hydro-physical properties. In this study, the impact of the type and number of input variables with five different methods of the Retc model to predicting the moisture retention curve and soil water content in three surfaces tillage NT (No-tillage), CP (Chisel Plough) and MP (Moldboard Plough) and the impact of tillage systems on soil hydro-physical properties were evaluated. According to results, when the field capacity and wilting point moisture was added to input data in Retc to predict the moisture curve model parameters, the EF was increased in MP (0.977, 0.95) and CP (0.891, 0.86) treatments compare the NT (0.665, 0.608). The Mualem–Van Genuchten model can describe satisfactorily the simulation of soil physical properties. The S-index, which was also affected by tillage, was greater than 0.066 in all tillage treatments, indicating good soil physical quality. Results indicated that NT had the highest and lowest values of bulk density (1.55 Mgr.m<sup>-3</sup>) and total available water (TAW) (0.038 m.m<sup>-1</sup>), respectively, and the differences between NT and MP in total porosity was significant. Overall, in most soil layers, tillage practices affected the porosity and total available water in the order MP &gt; CP &gt; NT. Water retention curves indicated that the water retention capacity was greater in tilled than in no-tilled and saturated hydraulic conductivity values were greater in tilled treatments than in NT soil.</p>


2021 ◽  
Author(s):  
Yexuan Liu ◽  
Wenjiao Shi ◽  
Fulu Tao ◽  
Xiaoli Shi

Abstract Forest ecosystems play a vital role in the earth’s hydrological process, and precipitation intercepted by forests accounts for more than a quarter of the water in the terrestrial hydrologic cycle. However, water retention in the three layers (canopy, litter, and soil) of forest ecosystems has not yet been thoroughly investigated on a global scale. Here, we investigate the global pattern of forest water retention capacity (WRC) and its controlling environmental factors based on 982 observations of 21 controlling factors in the three forest layers, mainly from 1990 to 2018. The results show that global WRC varies among the different forest types and climatic zones with a mean of 456.71 mm, while the average total water storage is 22,662.47 km3 in forest ecosystems. Climatic variables are the leading factors contributing to the variations in forest WRC, followed by forest structure factors, soil properties, terrain factors, and litter factors. This study advances our understanding of the mechanisms underlying large-scale variations in forest WRC in different climate zones and forest types. The findings demonstrate that controlling factors should be considered when developing policy for regions with important ecological functions. They also provide a benchmark to improve ecohydrological models for simulating global WRC.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2214
Author(s):  
Diego Rivera ◽  
Karen Gutierrez ◽  
Walter Valdivia-Cea ◽  
Mauricio Zambrano-Bigiarini ◽  
Alex Godoy-Faúndez ◽  
...  

Andean headwater catchments are key components of the hydrological cycle, given that they capture moisture, store water and release it for Chilean cities, industry, agriculture, and cities in Chile. However, knowledge about within-Andean catchment processes is far from clear. Most soils in the Andes derive from volcanic ash Andosols and Arenosols presenting high organic matter, high-water retention capacity and fine pores; and are very dry during summer. Despite their importance, there is little research on the hillslope hydrology of Andosols. Environmental isotopes such as Deuterium and 18-O are direct tracers for water and useful on analyzing water-soil interactions. This work explores, for the first time, the efficiency of cryogenic vacuum extraction to remove water from two contrasting soil types (Arenosols, Andosols) at five soil water retention energies (from −1500 to −33 kPa). Two experiments were carried out to analyse the impact of extraction time, and initial water content on the amount of extracted water, while a third experiment tested whether the cryogenic vacuum extraction changed the isotopic ratios after extraction. Minimum extraction times to recover over 90% of water initially in the soil samples were 40–50 min and varied with soil texture. Minimum volume for very dry soils were 0.2 mL (loamy sand) and 1 mL (loam). After extraction, the difference between the isotope standard and the isotopic values after extraction was acceptable. Thus, we recommend this procedure for soils derived from volcanic ashes.


Soil Systems ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 31 ◽  
Author(s):  
Francisco L. Pérez

This study examines litter accumulation and associated soil fertility islands under kūpaoa (Dubautia menziesii) shrubs, common at high elevations in Haleakalā National Park (Maui, Hawai’i). The main purposes were to: (i) Analyze chemical and physical properties of kūpaoa leaf-litter, (ii) determine soil changes caused by organic-matter accumulation under plants, and (iii) compare these with the known pedological effects of silversword (Argyroxiphium sandwicense) rosettes in the same area. Surface soil samples were gathered below shrubs, and compared with paired adjacent, bare sandy soils; two soil profiles were also contrasted. Litter patches under kūpaoa covered 0.57–3.61 m2 area and were 22–73 mm thick. A cohesive, 5–30-mm-thick soil crust with moderate aggregate stability developed underneath litter horizons; grain aggregation was presumably related to high organic-matter accumulation. Shear strength and compressibility measurements showed crusts opposed significantly greater resistance to physical removal and erosion than adjacent bare soils. As compared to contiguous bare ground areas, soils below shrubs had higher organic matter percentages, darker colors, faster infiltration rates, and greater water-retention capacity. Chemical soil properties were greatly altered by organic matter: Cations (Ca2+, Mg2+, K+), N, P, and cation-exchange capacity, were higher below plants. Further processes affecting soils under kūpaoa included microclimatic amelioration, and additional water input by fog-drip beneath its dense canopy. Substrate modifications were more pronounced below D. menziesii than A. sandwicense. Organic matter and available nutrient contents were higher under shrubs, where soils also showed greater infiltration and water-retention capacity. These trends resulted from contrasting litter properties between plant species, as kūpaoa leaves have higher nutrient content than silversword foliage. Different litter dynamics and reproduction strategies may also explain contrasting soil properties between the monocarpic rosettes and polycarpic kūpaoa. By inducing substantial substrate changes, Dubautia shrubs alter—or even create—different microhabitats and exert critical control on alpine soil development at Haleakalā.


Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1674
Author(s):  
Hsin-Fu Yeh ◽  
Tsien-Ting Huang ◽  
Jhe-Wei Lee

Rainfall infiltration is the primary triggering factor of slope instability. The process of rainfall infiltration leads to changes in the water content and internal stress of the slope soil, thereby affecting slope stability. The soil water retention curve (SWRC) was used to describe the relationship between soil water content, matric suction, and the water retention characteristics of the soil. This characteristic is essential for estimating the properties of unsaturated soils, such as unsaturated hydraulic conductivity function and shear strength. Thus, SWRC is regarded as important information for depicting the properties of unsaturated soil. The SWRC is primarily affected by the soil pore size distribution (PSD) and has unimodal and bimodal features. The bimodal SWRC is suitable for soils with structural or dual-porous media. This model can describe the structure of micropores and macropores in the soil and allow the hydraulic behavior at different pore scales to be understood. Therefore, this model is more consistent with the properties of onsite soil. Few studies have explored the differences in the impact of unimodal and bimodal models on unsaturated slopes. This study aims to consider unimodal and bimodal SWRC to evaluate the impact of unsaturated slope stability under actual rainfall conditions. A conceptual model of the slope was built based on field data to simulate changes in the hydraulic behavior of the slope. The results of seepage analysis show that the bimodal model has a better water retention capacity than the unimodal model, and therefore, its water storage performance is better. Under the same saturated hydraulic conductivity function, the wetting front of the bimodal model moves down faster. This results in changes in the pressure head, water content, and internal stress of the soil. The results show that the water content and suction stress changes of the bimodal model are higher than those of the unimodal model due to the difference in water retention capacity. Based on the stability of the slope, calculated using the seepage analysis, the results indicate that the potential failure depth of the bimodal model is deeper than that of the unimodal model.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David J. Peterman ◽  
Kathleen A. Ritterbush ◽  
Charles N. Ciampaglio ◽  
Erynn H. Johnson ◽  
Shinya Inoue ◽  
...  

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1510
Author(s):  
María Ángeles Rivas ◽  
Rocío Casquete ◽  
María de Guía Córdoba ◽  
Santiago Ruíz-Moyano ◽  
María José Benito ◽  
...  

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.


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