scholarly journals ВПЛИВ РЕКРЕАЦІЙНОГО НАВАНТАЖЕННЯ НА МОРФОЛОГІЧНІ ОСОБЛИВОСТІ ЛІСОВОЇ ПІДСТИЛКИ (НПП «СКОЛІВСЬКІ БЕСКИДИ» УКРАЇНСЬКІ КАРПАТИ)

2019 ◽  
pp. 63-74
Author(s):  
О. І. Леневич
Keyword(s):  
Forest Floor ◽  
Soil Cover ◽  
Warm Season ◽  
Forest Litter ◽  
Mountainous Region ◽  
Morphological Aspects ◽  
Tree Layer ◽  
Melt Water ◽  
Basic Parameters ◽  
The Impact

The article deals with the analysis of morphological aspects of the forest litter structure on ecological and tourist routes in the mountainous region. The study revealed that the changes in the basic parameters of the forest litter are caused by ground trampling. It was estimated that on trails between 0.5 m and 2 m wide, the stock of forest litter is 1.23-1.5 kg/m², and its capacity is 1.3-1.6 cm. With the supply of fresh foliage on the trails, the L, F and H sub-horizons can be identified there. On trails of 2 to 3 m wide, the stock of forest floor is 0.51-0.91 kg·m², that is almost twice less than on narrower trails. The capacity of the litter on trails more than 2 m wide is 0.3-0.5 cm, of which 0.2-0.4 is the F+H sub-horizon. On slopes with ≥ 15 º, the reserves and capacity of the forest litter in the lower part of the trail are about 10 % greater than in its upper part. Basically, the redistribution of forest litter is observed within a trail and its side. The stock of forest litter on the trail decreases due to the fact that the damaged litter is removed outside the trail. In the spring and summer, the forest litter is washed off by rain and melt water, forming the so-called “rollers” on its road (trail). The capacity and reserves of forest litter on the sidewalks are significantly dependent on the width and direction of the trail. The narrower the trail, the larger are the forest litter reserves and on the contary, the wider the trail, the smaller is the forest litter within the sidewalk. The capacity of the forest litter on the side of the trails of the studied routes ranges from 1.3 to 4.8 cm, and its reserves have increased to 1.44-2.26 kg·m². A composition of tree species, tree layer compactness and terrain play an important role in the formation of forest litter as well. The impact of recreation load on the soil cover was also evaluated. It was established that at the initial stages (of I-II categories) of recreation digression, the forest litter becomes compacted and crushed, forming a powerful F+H sub-horizon and covering the trail surface. As the recreation load increases (III stage/category) the stock of litter in spruce-beech-fir forest in the warm season is less than 1 kg/m².

scholarly journals Modelling and analyzing the surface fire behaviour in Hyrcanian forest of Iran

2014 ◽  
Vol 60 (No. 9) ◽  
pp. 353-362 ◽  
Author(s):  
H. Aghajani ◽  
A. Fallah ◽  
S. Fazlollah Emadian
Keyword(s):  
Forest Floor ◽  
Forest Litter ◽  
Fire Spread ◽  
Burned Area ◽  
Hyrcanian Forest ◽  
Fire Behaviour ◽  
Surface Fire ◽  
Contour Lines ◽  
Slope Wind ◽  
The Impact

The purpose of this study was to assess the forest fire behaviour and investigate the impact of different parameters on the spread of surface fire in the Hyrcanian forest of Iran. Surface fire was simulated using mathematical models in Microsoft Visual Basic 6.0 environment during a 30-minute time period. Several parameters that contributed to the speed of surface fire such as slope, wind velocity and litter thickness in the forest floor and various types of forest litter associated with hornbeam (Carpinus betulus L.), Persian ironwood (Parrotia persica C.A.M), beech (Fagus orientalis L.) and maple (Acer velutinum L.) were investigated. The results indicated that the maximum burned area was associated with beech litter. Forest surface fire demonstrated similar behaviour for the litter types of beech and Ironwood, whereas in the case of maple and hornbeam litters, the fire spread parallelly and perpendicularly to contour lines, respectively. The burned area increased in an irregular pattern as the forest floor slope gradient was increased. Moreover, the skewed pattern of the burned area for the forest floor composed of maple, beech, ironwood andhornbeam litter was described as high, low, moderate and low, respectively. The fire spread angle in forest floor associated with maple and beech litters changed with litter thickness. Finally, litter thickness had a significant effect on the direction of fire spread and this was more prominent with hornbeam litter.  

Solow economy model

2019 ◽  
pp. 150-157
Author(s):  
Oleksandr Synenko ◽  
Kateryna Yarema ◽  
Yuliia Bezsmertna
Keyword(s):  
Economic Growth ◽  
Regression Analysis ◽  
Solow Model ◽  
Economy Model ◽  
Accelerated Depreciation ◽  
Basic Parameters ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Model Algorithm

The subject of the research is the approach to the possibility of using the Solow model to perform the regression analysis on the example of the Ukrainian economy model. The purpose of writing this article is to investigate the notion of regres- sion analysis, Solow’s economy model, algorithm for performing regression analy- sis on the example of Ukraine’s economy model. This model can be adapted for the economy of enterprises. Methodology. The research methodology is system-struc- tural and comparative analyzes (to study the structure of GDP); monograph (when studying methods of regression analysis on the example of the Ukrainian economy); economic analysis (when assessing the impact of factors on Ukraine’s GDP). The scientific novelty consists the features of the use of the Solow model on the ex- ample of Ukrainian economy are determined. An algorithm for calculating the basic parameters of a model using the Excel application package is disclosed. The main recommendations on the development of the national economy and economic growth through the use of macroeconomic instruments are given. Conclusions. The use of the Solow model enables forecasting and analysis. The results obtained re- vealed the problem of low resource return of capital as a resource, along with the means of macroeconomic regulation of the investment process, using which can improve the situation. A special place in these funds belongs to the accelerated depreciation and interest rate policies.

A Predictive Model of the Impact of the Skidding System on Forest Soil in Severe Climatic Conditions

2020 ◽  
pp. 131-144
Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  
Keyword(s):  
Forest Soil ◽  
Warm Season ◽  
Climatic Conditions ◽  
Soil Freezing ◽  
Class Iii ◽  
Freezing And Thawing ◽  
Metal Structures ◽  
Rapid Adjustment ◽  
Soil Freezing And Thawing ◽  
The Impact

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.

European beech is a net annual source of methane (CH4)

2021 ◽  
Author(s):  
Katerina Machacova ◽  
Hannes Warlo ◽  
Kateřina Svobodová ◽  
Thomas Agyei ◽  
Tereza Uchytilová ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Seasonal Dynamics ◽  
Forest Floor ◽  
Greenhouse Gas Emission ◽  
European Beech ◽  
Individual Variability ◽  
Spatiotemporal Variability ◽  
Vegetation Season ◽  
Dormant Season ◽  
The Impact

<p>Trees are known to be sources of methane (CH<sub>4</sub>), an important greenhouse gas, into the atmosphere. However, still little is known about the seasonality of the tree stem CH<sub>4</sub> fluxes, particularly for the dormant season, and about the impact of environmental parameters on this gas exchange. This makes the estimation of net annual ecosystem CH<sub>4</sub> fluxes difficult.</p><p>We determined seasonal dynamics of CH<sub>4</sub> exchange of mature European beech stems (<em>Fagus sylvatica</em>) and of adjacent forest floor in a temperate montane forest of White Carpathians, Czech Republic, from November 2017 to December 2018. We used static chamber methods and gas chromatographic analyses. We aimed to understand the unknown role in seasonal changes of CH<sub>4</sub> fluxes of these forests, and the spatiotemporal variability of the tree fluxes.</p><p>The beech stems were net annual sources for atmospheric CH<sub>4</sub>, whereas the forest floor was a predominant sink for CH<sub>4</sub>. The stem CH<sub>4</sub> emissions showed high inter-individual variability and clear seasonality following the stem CO<sub>2</sub> efflux. The fluxes of CH<sub>4</sub> peaked during the vegetation season, and remained low but significant to the annual totals during winter dormancy. By contrast, the forest floor CH<sub>4</sub> uptake followed an opposite flux trend with low CH<sub>4</sub> uptake detected in the winter dormant season and elevated CH<sub>4</sub> uptake during the vegetation season. Based on our preliminary analyses, the detected high spatial variability in stem CH<sub>4</sub> emissions can be explained neither by the CH<sub>4</sub> exchange at the forest floor level, nor by soil CH<sub>4</sub> concentrations, soil water content and soil temperature, all measured in vertical soil profiles close to the studied trees.</p><p>European beech trees, native and widely spread species of Central Europe, seem to markedly contribute to the seasonal dynamics of the ecosystem CH<sub>4</sub> exchange, and their CH<sub>4</sub> fluxes should be included into forest greenhouse gas emission inventories.</p><p> </p><p><em>Acknowledgement</em></p><p><em>This research was supported by the Czech Science Foundation (17-18112Y), National Programme for Sustainability I (LO1415), CzeCOS (LM2015061), and SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). We thank Libor Borák and Leszek Dariusz Laptaszyński for their technical and field support.</em></p><p> </p>

scholarly journals Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs

2015 ◽  
Vol 15 (16) ◽  
pp. 9435-9453 ◽  
Author(s):  
G. Shi ◽  
A. M. Buffen ◽  
M. G. Hastings ◽  
C. Li ◽  
H. Ma ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Mass Fraction ◽  
Stratospheric Ozone ◽  
Warm Season ◽  
Cold Season ◽  
Depth Interval ◽  
Depositional Processes ◽  
Antarctic Snow ◽  
Exponential Change ◽  
The Impact

Abstract. Snowpits along a traverse from coastal East Antarctica to the summit of the ice sheet (Dome Argus) are used to investigate the post-depositional processing of nitrate (NO3−) in snow. Seven snowpits from sites with accumulation rates between 24 and 172 kg m−2 a−1 were sampled to depths of 150 to 300 cm. At sites from the continental interior (low accumulation, < 55 kg m−2 a−1), nitrate mass fraction is generally > 200 ng g−1 in surface snow and decreases quickly with depth to < 50 ng g−1. Considerably increasing values of δ15N of nitrate are also observed (16–461 ‰ vs. air N2), particularly in the top 20 cm, which is consistent with predicted fractionation constants for the photolysis of nitrate. The δ18O of nitrate (17–84 ‰ vs. VSMOW (Vienna Standard Mean Ocean Water)), on the other hand, decreases with increasing δ15N, suggestive of secondary formation of nitrate in situ (following photolysis) with a low δ18O source. Previous studies have suggested that δ15N and δ18O of nitrate at deeper snow depths should be predictable based upon an exponential change derived near the surface. At deeper depths sampled in this study, however, the relationship between nitrate mass fraction and δ18O changes, with increasing δ18O of nitrate observed between 100 and 200 cm. Predicting the impact of post-depositional loss, and therefore changes in the isotopes with depth, is highly sensitive to the depth interval over which an exponential change is assumed. In the snowpits collected closer to the coast (accumulation > 91 kg m−2 a−1), there are no obvious trends detected with depth and instead seasonality in nitrate mass fraction and isotopic composition is found. In comparison to the interior sites, the coastal pits are lower in δ15N (−15–71 ‰ vs. air N2) and higher in δ18O of nitrate (53–111 ‰ vs. VSMOW). The relationships found amongst mass fraction, δ15N, δ18O and Δ17O (Δ17O = δ17O–0.52 × δ18O) of nitrate cannot be explained by local post-depositional processes alone, and are instead interpreted in the context of a primary atmospheric signal. Consistent with other Antarctic observational and modeling studies, the isotopic results are suggestive of an important influence of stratospheric ozone chemistry on nitrate formation during the cold season and a mix of tropospheric sources and chemistry during the warm season. Overall, the findings in this study speak to the sensitivity of nitrate isotopic composition to post-depositional processing and highlight the strength of combined use of the nitrogen and oxygen isotopes for a mechanistic understanding of this processing.

scholarly journals Nitrogen and harvest impact on warm-season grass biomass yield and feedstock quality

2017 ◽  
Author(s):  
◽  
Chamara Sandaruwan Weerasekara Imbulana Acharige
Keyword(s):  
Biomass Yield ◽  
Warm Season ◽  
Early Spring ◽  
Harvest Date ◽  
Feedstock Quality ◽  
Harvest Timing ◽  
Bioenergy Feedstocks ◽  
Partial Factor ◽  
The Impact ◽  
Warm Season Grasses

Perennial warm-season grasses including switchgrass (Panicum virgatum L.), big bluestem (Andropogon geradii Vitman), and Indiangrass (Sorghastrum nutans L.) have drawn interest as bioenergy feedstocks due to their high yielding capacity with minimal amounts of inputs under a wide range of environments, and their capability to produce multiple environmental benefits. Nitrogen (N) fertility and harvest timing are considered as critical management practices when optimizing biomass yield and the feedstock quality of these grasses. The objective of this investigation was to quantify the impact of N fertilizer rate, N timing and harvest date on warm season biomass dry matter yield. Research was conducted in 2014 and 2015 on a total of four field-plot locations situated in central and west-central Missouri. Nitrogen fertilizer was applied using dry ammonium nitrate at the rates of 0, 34, 67, and 101 kg ha-1 at two application times, all N early spring and split N (early spring and following 1st harvest). Harvest treatments were as follows: 1) one cut in September; 2) one cut in November; 3) one cut in June and a second in September; and 4) one cut in June and a second in November. Treatments were arranged in a split-plot design with N rate as the main plot and harvest as the sub-plot in arandomized complete block design. Both N and harvest date and their interactions impacted biomass yield at all four locations. Delaying harvesting until late fall or killing frost increased yield. November harvest in combination with N rates grater than or equal to 67 kg ha-1 year-1 produced higher yields compared to the control and 34 kg ha-1N treatments and other harvest timing strategies. Although N was needed to optimize yield, partial factor 24 productivity (PFP) of applied N was flat when N applied was greater than 34 kg ha-1. Nitrogen fertilization at 67 kg ha-1 per growing season provided an opportunity to maintain a balance between both yield and efficiency of N inputs. Results of this research highlight the interactions of N fertilization and harvest management have when optimizing yield of warm-season grasses grown as bioenergy feedstocks. List of acronyms: N, Nitrogen; PFP, partial factor productivity.

scholarly journals The soil cover structure and elementary soil areas of the Opillia

2017 ◽  
pp. 390-398 ◽  
Author(s):  
Taras Yamelynets ◽  
Mykola Fedotikov
Keyword(s):  
Soil Structure ◽  
Soil Cover ◽  
Contrast Ratio ◽  
Study Results ◽  
Relief Sculpture ◽  
Soil Cover Structure ◽  
Basic Parameters ◽  
Basic Features ◽  
Quantitative Indicators ◽  
Qualitative And Quantitative Characteristics

For studying the soil cover structure of Opillia region, we used methods for the identification (natural-cartometric, relief sculpture, quality-genetic) and interpretation (statistical cartometric, functional and analytical) of the soil cover structure. The natural-cartometric method was used to characterize elementary soil areas of the key area, what makes it possible to determine the parameters of the soil structure and obtain quantitative indicators for the key elementary soil areas parameters, which are: elementary soil areas composition and area ratio, complexity, fractionality, breakdown, contrast ratio and heterogeneity. This article is devoted to the study results of qualitative and quantitative characteristics of elementary soil areas of the Opillia within Khodorivsko-Buchatskyi region, hereinafter Khodorivsko- Buchatske Opillia. With coefficient of the differentiation of the soil outlines and methods of variation statistics were identified and analyzed the degree of variability ESA areas. The degree of tortuosity and elongation of area limits using the coefficient of the dismemberment were studied. Investigated the character of outlines of elementary soil areals within the area of research. Identified the basic features of ESA borders depending on various environmental factors. The certain laws of changing of the basic parameters of elementary soil areas, which form the soil structure of Khodorivsko- Buchatske Opillia were determined and described in the article. Key words: elemental soil areal (ESA), soil structure (SS), coefficient of the differentiation of the soil outlines (CDSO), coefficient of dismemberment (CD), coefficient of variability (CV).

scholarly journals Representing icebergs in the <i>i</i>LOVECLIM model (version 1.0) – a sensitivity study

2014 ◽  
Vol 7 (4) ◽  
pp. 4353-4381
Author(s):  
M. Bügelmayer ◽  
D. M. Roche ◽  
H. Renssen
Keyword(s):  
Spatial Distribution ◽  
Size Distribution ◽  
Northern Hemisphere ◽  
Radiative Forcing ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Initial Size ◽  
Climate Conditions ◽  
Melt Water ◽  
The Impact

Abstract. Recent modelling studies have indicated that icebergs alter the ocean's state, the thickness of sea ice and the prevailing atmospheric conditions, in short play an active role in the climate system. The icebergs' impact is due to their slowly released melt water which freshens and cools the ocean. The spatial distribution of the icebergs and thus their melt water depends on the forces (atmospheric and oceanic) acting on them as well as on the icebergs' size. The studies conducted so far have in common that the icebergs were moved by reconstructed or modelled forcing fields and that the initial size distribution of the icebergs was prescribed according to present day observations. To address these shortcomings, we used the climate model iLOVECLIM that includes actively coupled ice-sheet and iceberg modules, to conduct 15 sensitivity experiments to analyse (1) the impact of the forcing fields (atmospheric vs. oceanic) on the icebergs' distribution and melt flux, and (2) the effect of the used initial iceberg size on the resulting Northern Hemisphere climate and ice sheet under different climate conditions (pre-industrial, strong/weak radiative forcing). Our results show that, under equilibrated pre-industrial conditions, the oceanic currents cause the bergs to stay close to the Greenland and North American coast, whereas the atmospheric forcing quickly distributes them further away from their calving site. These different characteristics strongly affect the lifetime of icebergs, since the wind-driven icebergs melt up to two years faster as they are quickly distributed into the relatively warm North Atlantic waters. Moreover, we find that local variations in the spatial distribution due to different iceberg sizes do not result in different climate states and Greenland ice sheet volume, independent of the prevailing climate conditions (pre-industrial, warming or cooling climate). Therefore, we conclude that local differences in the distribution of their melt flux do not alter the prevailing Northern Hemisphere climate and ice sheet under equilibrated conditions und constant supply of icebergs. Furthermore, our results suggest that the applied radiative forcing scenarios have a stronger impact on climate than the used initial size distribution of the icebergs.

scholarly journals Effect of deforestation and subsequent land-use management on soil carbon stocks in the South American Chaco

2018 ◽  
Author(s):  
Natalia Andrea Osinaga ◽  
Carina Rosa Álvarez ◽  
Miguel Angel Taboada
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Warm Season ◽  
Native Forest ◽  
Continuous Cropping ◽  
Organic C ◽  
Soil C ◽  
C Stocks ◽  
Chaco Region ◽  
The Impact

Abstract. Abstract. The sub-humid Chaco region of Argentina, originally covered by dry sclerophyll forest, has been subjected to clearing since the end of the '70 and replacement of the forest by no till farming. Land use changes produced a decrease in aboveground carbon stored in forests, but little is known about the impact on soil organic C stocks. The aim of this study was to evaluate soil C stocks and C fractions up to 1 m depth in soils under different land use:  20 yr continuous cropping, warm season grass pasture and native forest in 32 sites distributed over the Chaco region. The organic C stock content up to 1 m depth expressed as equivalent mass varied as follows: forest (119.3 Mg ha−1) > pasture (87.9 Mg ha−1) > continuous cropping (71.9 and 77.3 Mg ha−1), with no impact of the number of years under cropping. The most sensitive organic carbon fraction was the coarse particle fraction (2000 μm–212 μm) at 0–5 cm and 5–20 cm depth layers. Resistant carbon (

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