Olchev, Alexander

[["dc.bibliographiccitation.firstpage","6655"],["dc.bibliographiccitation.issue","22"],["dc.bibliographiccitation.journal","Biogeosciences"],["dc.bibliographiccitation.lastpage","6667"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Olchev, A."],["dc.contributor.author","Ibrom, A."],["dc.contributor.author","Panferov, O."],["dc.contributor.author","Gushchina, D."],["dc.contributor.author","Kreilein, H."],["dc.contributor.author","Popov, V."],["dc.contributor.author","Propastin, P."],["dc.contributor.author","June, T."],["dc.contributor.author","Rauf, A."],["dc.contributor.author","Gravenhorst, G."],["dc.contributor.author","Knohl, A."],["dc.date.accessioned","2017-09-07T11:49:05Z"],["dc.date.available","2017-09-07T11:49:05Z"],["dc.date.issued","2015"],["dc.description.abstract","The possible impact of El Niño–Southern Oscillation (ENSO) events on the main components of CO2 and H2O fluxes between the tropical rainforest and the atmosphere is investigated. The fluxes were continuously measured in an old-growth mountainous tropical rainforest in Central Sulawesi in Indonesia using the eddy covariance method for the period from January 2004 to June 2008. During this period, two episodes of El Niño and one episode of La Niña were observed. All these ENSO episodes had moderate intensity and were of the central Pacific type. The temporal variability analysis of the main meteorological parameters and components of CO2 and H2O exchange showed a high sensitivity of evapotranspiration (ET) and gross primary production (GPP) of the tropical rainforest to meteorological variations caused by both El Niño and La Niña episodes. Incoming solar radiation is the main governing factor that is responsible for ET and GPP variability. Ecosystem respiration (RE) dynamics depend mainly on the air temperature changes and are almost insensitive to ENSO. Changes in precipitation due to moderate ENSO events did not have any notable effect on ET and GPP, mainly because of sufficient soil moisture conditions even in periods of an anomalous reduction in precipitation in the region."],["dc.identifier.doi","10.5194/bg-12-6655-2015"],["dc.identifier.gro","3147096"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4815"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation","SFB 990 | A | A03: Untersuchung von Land-Atmosphäre Austauschprozesse in Landnutzungsänderungs-Systemen"],["dc.relation.issn","1726-4189"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.rights","CC BY 3.0"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Response of CO2 and H2O fluxes in a mountainous tropical rainforest in equatorial Indonesia to El Niño events"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","183"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Geography, Environment, Sustainability"],["dc.bibliographiccitation.lastpage","196"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Gushchina, Daria"],["dc.contributor.author","Heimsch, Florian"],["dc.contributor.author","Osipov, Alexander"],["dc.contributor.author","June, Tania"],["dc.contributor.author","Rauf, Abdul"],["dc.contributor.author","Kreilein, Heiner"],["dc.contributor.author","Panferov, Oleg"],["dc.contributor.author","Olchev, Alexander"],["dc.contributor.author","Knohl, Alexander"],["dc.date.accessioned","2019-11-14T15:25:25Z"],["dc.date.available","2019-11-14T15:25:25Z"],["dc.date.issued","2019"],["dc.description.abstract","The influence of the very strong 2015–16 El Niño event on local and regional meteorological conditions, as well as on energy and CO2 fluxes in a mountainous primary tropical rainforest was investigated using ERA-Interim reanalysis data as well as meteorological and eddy covariance flux measurements from Central Sulawesi in Indonesia. The El Niño event led to a strong increase of incoming monthly solar radiation and air temperature, simultaneously with the increasing Niño4 index. Monthly precipitation first strongly decreased and then increased reaching a maximum in 3–4 months after El Niño culmination. Ecosystem respiration increased while gross primary production showed only a weak response to the El Niño event resulting in a positive anomaly of net ecosystem CO2 exchange (reduced CO2 uptake). The changes of key meteorological parameters and fluxes caused by the strong El Niño event of 2015–16 differed from the effects of moderate El Niño events observed during the period 2003-2008, where net ecosystem CO2 exchange remained largely unaffected. In contrast to earlier moderate El Niño events, the strong El Niño 2015–16 affected mostly the air temperature resulting in a weakening of the net carbon sink at the rainforest site in Central Sulawesi, Indonesia."],["dc.identifier.doi","10.24057/2071-9388-2018-88"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62624"],["dc.language.iso","en"],["dc.relation","SFB 990: Ökologische und sozioökonomische Funktionen tropischer Tieflandregenwald-Transformationssysteme (Sumatra, Indonesien)"],["dc.relation","SFB 990 | A | A03: Untersuchung von Land-Atmosphäre Austauschprozesse in Landnutzungsänderungs-Systemen"],["dc.relation.issn","2542-1565"],["dc.relation.issn","2071-9388"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Effects Of The 2015–2016 El Niño Event On Energy And CO2 Fluxes Of A Tropical Rainforest In Central Sulawesi, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","131"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Ecological Modelling"],["dc.bibliographiccitation.lastpage","137"],["dc.bibliographiccitation.volume","212"],["dc.contributor.author","Olchev, A."],["dc.contributor.author","Ibrom, A."],["dc.contributor.author","Priess, J."],["dc.contributor.author","Erasmi, S."],["dc.contributor.author","Leemhuis, Constanze"],["dc.contributor.author","Twele, Andre"],["dc.contributor.author","Radler, K. H."],["dc.contributor.author","Kreilein, Heinrich"],["dc.contributor.author","Panferov, Oleg"],["dc.contributor.author","Gravenhorst, Gode"],["dc.date.accessioned","2018-11-07T11:17:04Z"],["dc.date.accessioned","2020-05-11T13:29:09Z"],["dc.date.available","2018-11-07T11:17:04Z"],["dc.date.available","2020-05-11T13:29:09Z"],["dc.date.issued","2008"],["dc.description.abstract","The impact of deforestation and land-use changes on evapotranspiration of mountainous tropical rain forest area in the northern part of the Lore-Lindu National Park (LLNP) in Central Sulawesi (Indonesia) was quantified using a regional process-based SVAT model \"SVAT-Regio\". Description of evapotranspiration of a non-uniform land surface in local and regional scales in SVAT-Regio is based on equations of energy and water balances of individual plants, plant canopy and soil layers for each of many grid cells into which the entire study area is divided. The model uses a multi-layered representation of vegetation cover and soil structure that allows to describe the partitioning of energy and H2O-fluxes among different canopy layers and soil, and to quantify more precisely the total ecosystem fluxes. Selective integration of grid cell fluxes on space and time allows estimating the energy and water fluxes for e.g. ecosystems, catchments or entire study area for different time spans from 1 day to several years. September of 2004 was selected as a test period for modelling experiments. The regional patterns of meteorological parameters were reconstructed using measurements provided by 10 mobile meteorological stations. Ecophysiological parameters for different vegetation types were determined from own measurements as well as from results of previous scientific studies in the area. The present spatial distribution of the different land-use types was described from analysis of LANDSAT ETM+ observations. The spatial pattern of leaf area index (LAI) was derived from analysis of NDVI data (calculated from LANDSAT ETM+ data) and field measurements at key experimental plots. A deforestation scenario (allowing for mainly anthropogenic impacts) which was applied in this study assumes a relatively strong decrease of the areas covered by tropical rain forests, i.e. about 15%, and an increase of agricultural (coffee plantations, corn and rice fields) and urban areas. Moreover, the scenario assumes a small increase of grassland areas as well. The results of modelling experiments show that 15% deforestation of the study area results in relatively small decrease of monthly evapotranspiration by about 2%, transpiration by about 6% and interception evaporation by about 5%, as well as an increase of soil evaporation by about 21%. The evapotranspiration decrease was highest in days with cloudy and rainy weather conditions, and lowest in sunny and dry days. (c) 2007 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.ecolmodel.2007.10.022"],["dc.identifier.isi","000254227100017"],["dc.identifier.scopus","2-s2.0-38949186752"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/65057"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54725"],["dc.identifier.url","http://www.scopus.com/inward/record.url?eid=2-s2.0-38949186752&partnerID=MN8TOARS"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0304-3800"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.title","Effects of land-use changes on evapotranspiration of tropical rain forest margin area in Central Sulawesi (Indonesia): Modelling study with a regional SVAT model"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4405"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Biogeosciences Discussions"],["dc.bibliographiccitation.lastpage","4431"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Olchev, A."],["dc.contributor.author","Ibrom, A."],["dc.contributor.author","Panferov, O."],["dc.contributor.author","Gushchina, D."],["dc.contributor.author","Propastin, P."],["dc.contributor.author","Kreilein, H."],["dc.contributor.author","June, T."],["dc.contributor.author","Rauf, A."],["dc.contributor.author","Gravenhorst, G."],["dc.contributor.author","Knohl, A."],["dc.date.accessioned","2019-07-09T11:42:04Z"],["dc.date.available","2019-07-09T11:42:04Z"],["dc.date.issued","2015"],["dc.description.abstract","The possible impact of El Niño–Southern Oscillation (ENSO) events on the main components of CO2 and H2O fluxes between the tropical rainforest and the atmosphere is investigated. The fluxes were continuously measured in an old-growth mountainous tropical rainforest in Central Sulawesi in Indonesia using the eddy covariance method for the period from January 2004 to June 2008. During this period, two episodes of El Niño and one episode of La Niña were observed. All these ENSO episodes had moderate intensity and were of the central Pacific type. The temporal variability analysis of the main meteorological parameters and components of CO2 and H2O exchange showed a high sensitivity of evapotranspiration (ET) and gross primary production (GPP) of the tropical rainforest to meteorological variations caused by both El Niño and La Niña episodes. Incoming solar radiation is the main governing factor that is responsible for ET and GPP variability. Ecosystem respiration (RE) dynamics depend mainly on the air temperature changes and are almost insensitive to ENSO. Changes in precipitation due to moderate ENSO events did not have any notable effect on ET and GPP, mainly because of sufficient soil moisture conditions even in periods of an anomalous reduction in precipitation in the region."],["dc.description.sponsorship","Open-Access Publikationsfonds 2015"],["dc.identifier.doi","10.5194/bgd-12-4405-2015"],["dc.identifier.fs","616105"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/12761"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/58580"],["dc.language.iso","en"],["dc.relation.issn","1810-6285"],["dc.rights.access","openAccess"],["dc.title","Response of CO2 and H2O fluxes of a mountainous tropical rain forest in equatorial Indonesia to El Niño events"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","245"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Geography, Environment, Sustainability"],["dc.bibliographiccitation.lastpage","258"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Tiralla, Nina"],["dc.contributor.author","Panferov, Oleg"],["dc.contributor.author","Kreilein, Heinrich"],["dc.contributor.author","Olchev, Alexander"],["dc.contributor.author","Ali, Ashehad A."],["dc.contributor.author","Knohl, Alexander"],["dc.contributor.orcid","0000-0002-7328-306X"],["dc.date.accessioned","2022-03-09T12:38:34Z"],["dc.date.available","2022-03-09T12:38:34Z"],["dc.date.issued","2019"],["dc.description.abstract","Climate change has distinct regional and local differences in its impacts on the land sur face. One of the important parameters determining the climate change signal is the emissivity (ε) of the sur face. In forest-climate interactions, the leaf sur face emissivity plays a decisive role. The accurate determination of leaf emissivities is crucial for the appropriate interpretation of measured energy and matter fluxes between the forest and the atmosphere. In this study, we quantified the emissivity of the five broadleaf tree species Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior, Populus simonii and Populus candicans. Measurements of leaf sur face temperatures were conducted under laboratory conditions in a controlled-climate chamber within the temperature range of +8 °C and +32°C. Based on these measurements, broadband leaf emissivities ε (ε for the spectral range of 8-14 µm) were calculated. Average ε8-14 µm was 0.958±0.002 for all species with very little variation among species. In a second step, the soil-vegetation-atmosphere transfer model ‘MixFor-SVAT ’ was applied to examine the effects of ε changes on radiative, sensible and latent energy fluxes of the Hainich forest in Central Germany. Model experiments were driven by meteorological data measured at the Hainich site. The simulations were forced with the calculated ε value as well as with minimum and maximum values obtained from the literature. Significant effects of ε changes were detected. The strongest effect was identified for the sensible heat flux with a sensitivity of 20.7 % per 1 % ε change. Thus, the variability of ε should be considered in climate change studies."],["dc.identifier.doi","10.24057/2071-9388-2018-86"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/114311"],["dc.identifier.url","https://publications.goettingen-research-online.de/handle/2/62623"],["dc.language.iso","en"],["dc.relation.doi","10.24057/2071-9388-2018-86"],["dc.relation.issn","2542-1565"],["dc.relation.issn","2071-9388"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.subject.gro","Leaf emissivity"],["dc.title","Quantification Of Leaf Emissivities Of Forest Species: Effects On Modelled Energy And Matter Fluxes In Forest Ecosystems"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3046"],["dc.bibliographiccitation.issue","21"],["dc.bibliographiccitation.journal","Ecological Modelling"],["dc.bibliographiccitation.lastpage","3056"],["dc.bibliographiccitation.volume","220"],["dc.contributor.author","Olchev, A."],["dc.contributor.author","Radler, K."],["dc.contributor.author","Sogachev, A."],["dc.contributor.author","Panferov, Oleg"],["dc.contributor.author","Gravenhorst, Gode"],["dc.date.accessioned","2018-11-07T11:22:09Z"],["dc.date.available","2018-11-07T11:22:09Z"],["dc.date.issued","2009"],["dc.description.abstract","A three-dimensional model Mixfor-3D of soil-vegetation-atmosphere transfer (SVAT) was developed and applied to estimate possible effects of tree clear-cutting on radiation and soil temperature regimes of a forest ecosystem. The Mixfor-31D model consists of several closely coupled 3D sub-models describing: forest stand structure; radiative transfer in a forest canopy; turbulent transfer of sensible heat, H(2)O and CO(2) between ground surface and the atmospheric surface layer; evapotranspiration of ground surface vegetation and soil; heat and moisture transfer in soil. The model operates with the horizontal grid resolution, 2 m x 2 m; vertical resolution, 1 m and primary time step, 1 h. The model was tested against meteorological data obtained at a small clear-cutting area in Otterbach in central Germany during summer 2005. The meteorological data including air temperature and humidity, precipitation, solar radiation, wind speed and direction, soil temperatures at 10 and 20 cm depth were measured by five automatic stations within the clear-cut area. One reference station was placed about 100 m from the clear-cut inside the forest stand. Comparisons of modelled and measured solar radiation fluxes and soil temperature profiles showed that the model adequately describes the spatial heterogeneity and dynamics of these variables under different weather conditions. The model can be used to explore solar radiation and soil temperature patterns within heterogeneous forest plots, with applications to various silvicultural tasks. (C) 2009 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.ecolmodel.2009.02.004"],["dc.identifier.isi","000272332900021"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55933"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","6th European Conference on Ecological Modelling, Challenges for Ecological Modelling in a Changing World"],["dc.relation.eventlocation","Trieste, ITALY"],["dc.relation.issn","0304-3800"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.title","Application of a three-dimensional model for assessing effects of small clear-cuttings on radiation and soil temperature"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]