Wyniki wyszukiwania

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Effect of different methods of management of post clear cutting residues on soil carbon content

100%

Galazka S., Gornowicz R., Pilarek Z.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2007

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tom 06

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nr 4

Forests play a very important role in the process of the carbon cycle in the natural environment and timber harvesting disturbs the natural circulation of this element considerably. Moreover, the way of handling the post clear cutting residues can also influence the accumulation of carbon in the soil. Usually, increased contents of organic carbon in the near-surface layers of mineral forest soils were observed in the first year following the stand removal. The greatest soil carbon enrichment was recorded when branches were ground and mixed with the mineral soil. Considerable variations in the observed contents of organic carbon in the near-surface layer of mineral soils during the first two years after clear cutting and later makes it impossible to indicate the most advantageous method of management of post clear cutting residues.

2

Diurnal changes in the isotope composition of atmospheric CO2 in Krakow

100%

Zimnoch M., Necki J., Florkowski T.

Geographia Polonica

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1995

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tom 65

3

C-biomass of bacteria, fungi, and protozoan communities in Arctic turdra soil, including some trophic relationships

84%

Anderson O. R., McGuire K.

Acta Protozoologica

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2013

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tom 52

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nr 4

4

Measurements of carbon dioxide fluxes by chamber method at the Rzecin wetland ecosystem, Poland

84%

Chojnicki B. H., Michalak M., Acosta M., Juszczak R., Augustin J., Drosler M., Olejnik J.

Polish Journal of Environmental Studies

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2010

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tom 19

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nr 2

283-291

The assessment of net ecosystem exchange (NEE) and respiration of ecosystem (Reco) of terrestrial ecosystems is necessary to improve our knowledge about the carbon cycle. The aims of this paper were to present reliable measurements of CO₂ fluxes of a temperate bog ecosystem located in Poland using a closed dynamic chamber system and to obtain a daily dynamic course of CO₂ fluxes over the 2007 vegetation season. Measurements of CO₂ fluxes were carried out at Rzecin peatland ecosystem located in northwestern Poland using the set of two chambers (dark and transparent). Reco during the experiment period ranged from 2.65 to 14.76 μmolCO₂ ・m⁻²・s⁻¹. The daily run of NEE was inversed to PPFD and the values of NEE varied from 0.06 to -11.82 μmolCO₂・m⁻²・s⁻¹. We found differences between NEE and Reco in the wetland ecosystem with respect to term of measurements. The PPFD, air and soil temperatures explain most temporal variability of CO₂ fluxes at Rzecin. But vegetation structure, its phenology and water-level depth seem also to play important roles. The chamber technique is a useful tool for determining carbon dioxide exchange between wetland surface and the atmosphere.

5

Comparison of the variation of soil respiration in carbon cycle in temperate and subtropical forests and the relationship with climatic variables

84%

Shi Z., Zhang Y., Chen B., Zhou W., Du E., Fang J.

Polish Journal of Ecology

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2015

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tom 63

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nr 3

Forest soil respiration (SR) has become a vital issue in global change ecology because of its critical role in global warming processes. However, SR remains the least understood component of the terrestrial carbon cycle because of its high spatial-temporal variability, inaccessibility of the soil substrate, and the high cost of measurement equipment. This study investigated the spatial and temporal variations of SR in six temperate and subtropical forest sites in eastern China. Seasonal variations of SR, the relationship between SR and soil temperature (ST) and volumetric water content (SW) were analyzed. Mean monthly SR varied seasonally and peaked in summer. SR varied temporally with ST (R² = 0.43∼0.79) in different sites and varied spatially with latitude (R² = 0.68). The responses of SR to the changes of SW varied across different sites and forest types. Their relationships were simulated by piecewise functions in the north three sites. The modules of ST and SW showed that ST is the dominant environmental factor in regulating seasonal dynamics of SR. This study is the first to examine the temporal and spatial variations of SR using a consistent method in situ in temperate and subtropical forests in eastern China. The results provide a scientific basis for accurately assessing future soil CO₂ efflux as a result of climate changes, and aid predictions of the changes of forest SR.

6

Emergy and value of the net primary production (NPP) above ground in natural areas

84%

Siche R., Ortega E.

Ecological Questions

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2008

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tom 10

7

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Variability of the marine boundary layer parameters over Baltic Sea sub-basins and their impact on nitrogen deposition

67%

Hongisto M.

Oceanologia

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2011

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tom 53

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nr (1-TI)

The variability of the marine boundary layer parameters over the Baltic Sea and its sub-basins and their impact on the 6 h, monthly or seasonal deposition of oxidized nitrogen compounds was studied using results of the Hilatar chemistrytransport model, the 6th hour forecasts of the HIRLAM weather prediction model and meteorological measurement data. The monthly load of oxidized nitrogen was highest in the winters of 1993–1995 and 2000, and lowest in 1996–1997 and 2005; no trend was detected. Short-time correlations were low, but a significant correlation of the monthly deposition with the NAO index and ice-season was found over northern sub-basins.

8

Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using Integrated Biosphere Simulator (IBIS) model

67%

Zhu Q., Jiang H., Liu J., Peng C., Fang X., Yu S., Zhou G., Wei X., Ju W.

Polish Journal of Ecology

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2011

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tom 59

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nr 1

The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the impacts of climate change and CO2 fertilization on net primary production (NPP), net ecosystem production (NEP), and the vegetation structure of terrestrial ecosystems in Zhejiang province (area 101,800 km2, mainly covered by subtropical evergreen forest and warm-temperate evergreen broadleaf forest) which is located in the subtropical climate area of China. Two general circulation models (HADCM3 and CGCM3) representing four IPCC climate change scenarios (HC3AA, HC3GG, CGCM-sresa2, and CGCM-sresb1) were used as climate inputs for IBIS. Results show that simulated historical biomass and NPP are consistent with field and other modelled data, which makes the analysis of future carbon budget reliable. The results indicate that NPP over the entire Zhejiang province was about 55 Mt C yr-1 during the last half of the 21st century. An NPP increase of about 24 Mt C by the end of the 21st century was estimated with the combined effects of increasing CO2 and climate change. A slight NPP increase of about 5 Mt C was estimated under the climate change alone scenario. Forests in Zhejiang are currently acting as a carbon sink with an average NEP of about 2.5 Mt C yr–1. NEP will increase to about 5 Mt C yr–1 by the end of the 21st century with the increasing atmospheric CO2 concentration and climate change. However, climate change alone will reduce the forest carbon sequestration of Zhejiang’s forests. Future climate warming will substantially change the vegetation cover types; warm-temperate evergreen broadleaf forest will be gradually substituted by subtropical evergreen forest. An increasing CO2 concentration will have little contribution to vegetation changes. Simulated NPP shows geographic patterns consistent with temperature to a certain extent, and precipitation is not the limiting factor for forest NPP in the subtropical climate conditions. There is no close relationship between the spatial pattern of NEP and climate condition.

9

Particulate organic carbon in the Southern Baltic Sea: numerical simulations and experimental data

67%

Dzierzbicka-Glowacka L., Kulinski K., Maciejewska A., Jakacki J., Pempkowiak J.

Oceanologia

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2010

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tom 52

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nr 4

Particulate Organic Carbon (POC) is an important component in the carbon cycle of land-locked seas. In this paper, we assess the POC concentration in the Gdańsk Deep, southern Baltic Sea. Our study is based on both a 1D POC Model and current POC concentration measurements. The aim is twofold: (i) validation of simulated concentrations with actual measurements, and (ii) a qualitative assessment of the sources contributing to the POC pool. The POC model consists of six coupled equations: five diffusion-type equations for phytoplankton, zooplankton, pelagic detritus and nutrients (phosphate and total inorganic nitrogen) and one ordinary differential equation for detritus at the bottom. The POC concentration is determined as the sum of phytoplankton, zoo-plankton and pelagic detritus concentrations, all expressed in carbon equivalents. Bacteria are not simulated in this paper. The observed large fluctuations of POC concentrations are attributed to its appreciable seasonal variability. The maximum concentration of POC varied between 870 mgC m−3 in May and 580 mgC m−3 in September, coinciding with the period of maximum dead organic matter and phytoplankton biomass concentrations. The results of the numerical simulations are in good agreement with observed values. The difference between the modelled and observed POC concentrations is equal to 3–28% and depends on the month for which the calculations were made, although no time trend of the difference is observed. The conclusion is that the numerical simulations are a ufficiently good reflection of POC dynamics in the Baltic.

Ograniczanie wyników

Effect of different methods of management of post clear cutting residues on soil carbon content

Diurnal changes in the isotope composition of atmospheric CO2 in Krakow

C-biomass of bacteria, fungi, and protozoan communities in Arctic turdra soil, including some trophic relationships

Measurements of carbon dioxide fluxes by chamber method at the Rzecin wetland ecosystem, Poland

Comparison of the variation of soil respiration in carbon cycle in temperate and subtropical forests and the relationship with climatic variables

Emergy and value of the net primary production (NPP) above ground in natural areas

Variability of the marine boundary layer parameters over Baltic Sea sub-basins and their impact on nitrogen deposition

Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using Integrated Biosphere Simulator (IBIS) model

Particulate organic carbon in the Southern Baltic Sea: numerical simulations and experimental data