Search

We measured methane (CH4) exchange rates with automatic chambers at the forest floor of a nutrient-rich drained peatland in 2011-2013. The fen, located in southern Finland, was drained for forestry in 1969 and the tree stand is now a mixture of Scots pine, Norway spruce, and pubescent birch. Our measurement system consisted of six transparent chambers and stainless steel frames, positioned on a number of different field and moss layer compositions. Gas concentrations were measured with an online cavity ring-down spectroscopy gas analyzer. Fluxes were calculated with both linear and exponential regression. The use of linear regression resulted in systematically smaller CH4 fluxes by 10-45% as compared to exponential regression. However, the use of exponential regression with small fluxes (

Hydrologic conditions are a major controlling factor for carbon exchange processes in high-latitude ecosystems. The presence or absence of water-logged conditions can lead to significant shifts in ecosystem structure and carbon cycle processes. In this study, we compared growing season CO2 fluxes of a wet tussock tundra ecosystem from an area affected by decadal drainage to an undisturbed area on the Kolyma floodplain in northeastern Siberia. For this comparison we found the sink strength for CO2 in recent years (2013-2015) to be systematically reduced within the drained area, with a minor increase in photosynthetic uptake due to a higher abundance of shrubs outweighed by a more pronounced increase in respiration due to warmer near-surface soil layers. Still, in comparison to the strong reduction of fluxes immediately following the drainage disturbance in 2005, recent CO2 exchange with the atmosphere over this disturbed part of the tundra indicate a higher carbon turnover, and a seasonal amplitude that is comparable again to that within the control section. This indicates that the local permafrost ecosystem is capable of adapting to significantly different hydrologic conditions without losing its capacity to act as a net sink for CO2 over the growing season. The comparison of undisturbed CO2 flux rates from 2013-2015 to the period of 2002-2004 indicates that CO2 exchange with the atmosphere was intensified, with increased component fluxes (ecosystem respiration and gross primary production) over the past decade. Net changes in CO2 fluxes are dominated by a major increase in photosynthetic uptake, resulting in a stronger CO2 sink in 2013-2015. Application of a MODIS-based classification scheme to separate the growing season into four sub-seasons improved the interpretation of interannual variability by illustrating the systematic shifts in CO2 uptake patterns that have occurred in this ecosystem over the past 10 years and highlighting the important role of the late g

Purpose. The study of reasons of under flooding of 101 settlements is conducted in three districts of south-west of the Odessa area. An aim hired consists of ground and drafting of databases (electronic and cartographic) impounded and potentially-impounded settlements of some districts of south-west of the Odessa area. A research object is settlements of three districts – Kiliya, Tarutino and Tatarbunar. The article of research is reasons of under flooding,along with the places of possible flood because of floods or other natural calamities.Methodology. The basic task of the carried out works was a receipt of reliable information, relatively impounded and potentially-impounded territories within the limits of settlements (SM) for the further acceptance of administrative decisions, in relation to each separate SM.Finding. In connection with absence of regime-observant network and some regime supervisions was worked out and applied approach which consisted of four stages. On results all stages regime-observant points were selected in which the annual watching is conducted a level and chemical composition of subsoil waters. Annual monitoring supervisions for the last ten years and generalization of their results allowed to make the maps of the territoriesimpounded and potentially impounded, distinguish the places of possible flood within the limits of every SM, to define principal reasons of presence of the territories impounded and potentially impounded within the limits of three districts.Results. The brought going over near the study of this problem allows more in detail to study and control the processes of under flooding in every settlement at the different degree of working out in detail., Проведено изучение причин подтопления 101 населённого пункта в трех районах юго-запада Одесской области, определены подтопленные и потенциально подтопленные территории в пределах каждого населенного пункта. По результатам обработки полученных данных были составлены карты десяти тысячного масштаба с указанием максимально возможных отрицательных явлений в пределах каждого населенного пункта. Указанны места возможного затопления части территории, вследствие наводнений или значительных осадков. Определенны основные причины наличия подтопленных и потенциально подтопленных территорий в пределах районов., Проведено дослідження причин підтоплення 101 населеного пункту в трьох районах південного заходу Одеської області, визначено підтоплені і потенційно підтоплені території в межах кожного населеного пункту. В наслідок обробки отриманих даних були складені карти десятитисячного масштабу з зазначенням максимально можливих негативних явищ в межах кожного населеного пункту. Окрім цього вказані місця можливого затоплення частини території в наслідок повеней або значних опадів. Визначені основні причини наявності підтоплених і потенційно підтоплених територій в межах районів.

This paper analyses a reconstruction of changes from the 17th to the 20th centuries in peat bogs with Erica ciliaris Loefl. ex L. heathlands in southwestern Europe. The reconstruction is performed by means of a multidisciplinary method based on photointerpretation, the examination of historical sources (documentation and maps), and an analysis of microtopography. Historical sources and aerial photos from 1956 and 1987 have also been used to reconstruct the impacts of anthropic activity. In the study area, Doñana Natural Park (SW Iberian Peninsula), peat bogs currently occupy slightly more than 8% of the area that they covered at the beginning of the 17th century. A parallel analysis of anthropic activity in the area over the last four centuries reveals the key role of humans in the disappearance of these peat bogs. This drastic reduction of peat bog area during the 20th century is due to a lowering of the water-table as a result of the impacts of anthropic activity, primarily the establishment of monocultures of Eucalyptus spp. and Pinus pinea. An earlier lowering of the water-table, before these plantations, is attributable to a process of aridisation associated with post-'Little Ice Age' warming. Therefore, the impacts associated with climatic trends are synergistically superimposed on those derived from the intense anthropic activity that occurred during the second half of the 20th century. This synergy resulted in a reduction of the surface occupied by the studied peat bogs and their associated E. ciliaris heathlands by 91.1% in SW Europe.

This paper analyses a reconstruction of changes from the 17th to the 20th centuries in peat bogs with Erica ciliaris Loefl. ex L. heathlands in southwestern Europe. The reconstruction is performed by means of a multidisciplinary method based on photointerpretation, the examination of historical sources (documentation and maps), and an analysis of microtopography. Historical sources and aerial photos from 1956 and 1987 have also been used to reconstruct the impacts of anthropic activity. In the study area, Doñana Natural Park (SW Iberian Peninsula), peat bogs currently occupy slightly more than 8% of the area that they covered at the beginning of the 17th century. A parallel analysis of anthropic activity in the area over the last four centuries reveals the key role of humans in the disappearance of these peat bogs. This drastic reduction of peat bog area during the 20th century is due to a lowering of the water-table as a result of the impacts of anthropic activity, primarily the establishment of monocultures of Eucalyptus spp. and Pinus pinea. An earlier lowering of the water-table, before these plantations, is attributable to a process of aridisation associated with post-'Little Ice Age' warming. Therefore, the impacts associated with climatic trends are synergistically superimposed on those derived from the intense anthropic activity that occurred during the second half of the 20th century. This synergy resulted in a reduction of the surface occupied by the studied peat bogs and their associated E. ciliaris heathlands by 91.1% in SW Europe.

This paper analyses a reconstruction of changes from the 17th to the 20th centuries in peat bogs with Erica ciliaris Loefl. ex L. heathlands in southwestern Europe. The reconstruction is performed by means of a multidisciplinary method based on photointerpretation, the examination of historical sources (documentation and maps), and an analysis of microtopography. Historical sources and aerial photos from 1956 and 1987 have also been used to reconstruct the impacts of anthropic activity. In the study area, Doñana Natural Park (SW Iberian Peninsula), peat bogs currently occupy slightly more than 8% of the area that they covered at the beginning of the 17th century. A parallel analysis of anthropic activity in the area over the last four centuries reveals the key role of humans in the disappearance of these peat bogs. This drastic reduction of peat bog area during the 20th century is due to a lowering of the water-table as a result of the impacts of anthropic activity, primarily the establishment of monocultures of Eucalyptus spp. and Pinus pinea. An earlier lowering of the water-table, before these plantations, is attributable to a process of aridisation associated with post-'Little Ice Age' warming. Therefore, the impacts associated with climatic trends are synergistically superimposed on those derived from the intense anthropic activity that occurred during the second half of the 20th century. This synergy resulted in a reduction of the surface occupied by the studied peat bogs and their associated E. ciliaris heathlands by 91.1% in SW Europe.

This paper analyses a reconstruction of changes from the 17th to the 20th centuries in peat bogs with Erica ciliaris Loefl. ex L. heathlands in southwestern Europe. The reconstruction is performed by means of a multidisciplinary method based on photointerpretation, the examination of historical sources (documentation and maps), and an analysis of microtopography. Historical sources and aerial photos from 1956 and 1987 have also been used to reconstruct the impacts of anthropic activity. In the study area, Doñana Natural Park (SW Iberian Peninsula), peat bogs currently occupy slightly more than 8% of the area that they covered at the beginning of the 17th century. A parallel analysis of anthropic activity in the area over the last four centuries reveals the key role of humans in the disappearance of these peat bogs. This drastic reduction of peat bog area during the 20th century is due to a lowering of the water-table as a result of the impacts of anthropic activity, primarily the establishment of monocultures of Eucalyptus spp. and Pinus pinea. An earlier lowering of the water-table, before these plantations, is attributable to a process of aridisation associated with post-'Little Ice Age' warming. Therefore, the impacts associated with climatic trends are synergistically superimposed on those derived from the intense anthropic activity that occurred during the second half of the 20th century. This synergy resulted in a reduction of the surface occupied by the studied peat bogs and their associated E. ciliaris heathlands by 91.1% in SW Europe.

Methane (CH4) emissions were compared for an intensively and extensively managed agricultural area on peat soils in the Netherlands to evaluate the effect of reduced management on the CH4 balance. Chamber measurements (photoacoustic methods) for CH4 were performed for a period of three years in the contributing landscape elements in the research sites. Various factors influencing CH4 emissions were evaluated and temperature of water and soil was found to be the main driver in both sites. For upscaling of CH4 fluxes to landscape scale, regression models were used which were specific for each of the contributing landforms. Ditches and bordering edges were emission hotspots and emitted together between 60% and 70% of the total terrestrial CH4 emissions. Annual terrestrial CH4 fluxes were estimated to be 203 (±48%), 162 (±60%) and 146 (±60%) kg CH4 ha-1 and 157 (±63%), 180 (±54%) and 163 (±59%) kg CH4 ha-1 in the intensively managed site and extensively managed site, for 2006, 2007 and 2008 respectively. About 70% of the CH4 was emitted in the summer period. Farm based emissions caused per year an additional 257 kg CH4 ha-1 and 172 kg CH4 ha-1 for the intensively managed site and extensively managed site, respectively. To further evaluate the effect of agricultural activity on the CH4 balance, the annual CH4 fluxes of the two managed sites were also compared to the emissions of a natural peat site with no management and high ground water levels. By comparing the terrestrial and additional farm based emissions of the three sites, we finally concluded that transformation of intensively managed agricultural land to nature development will lead to an increase in terrestrial CH4 emission, but will not by definition lead to a significant increase in CH4 emission when farm based emissions are included

[1] Methane fluxes were measured at five sites representing oligotrophic peatlands along a European transect. Five study plots were subjected to elevated CO2 concentration (560 ppm), and five plots to NH4NO3 (3 or 5 g N yr(-1)). The CH4 emissions from the control plots correlated in most cases with the soil temperatures. The depth of the water table, the pH, and the DOC, N and SO4 concentrations were only weakly correlated with the CH4 emissions. The elevated CO2 treatment gave nonsignificantly higher CH4 emissions at three sites and lower at two sites. The N treatment resulted in higher methane emissions at three sites (nonsignificant). At one site, the CH4 fluxes of the N-treatment plots were significantly lower than those of the control plots. These results were not in agreement with our hypotheses, nor with the results obtained in some earlier studies. However, the results are consistent with the results of the vegetation analyses, which showed no significant treatment effects on species relationships or biomass production.

The Gojo-shi area in southern Nara ken consists of the pre- Tertiary Izumi Formation, the Ryoke Senan Complex and Sambagawa metamorphic rocks, along with younger sediments of the Shobudani Formation (Pleistocene), terrace and recent deposits. Sediments of the Shobudani Formation, consisting of gravel, sand, silt and clay, form an excellent aquifer system in the southwestern part....

The Gojo-shi area in southern Nara ken consists of the pre- Tertiary Izumi Formation, the Ryoke Senan Complex and Sambagawa metamorphic rocks, along with younger sediments of the Shobudani Formation (Pleistocene), terrace and recent deposits. Sediments of the Shobudani Formation, consisting of gravel, sand, silt and clay, form an excellent aquifer system in the southwestern part....