Olchev, Alexander

[["dc.bibliographiccitation.firstpage","359"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Forests"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Ali, Ashehad A."],["dc.contributor.author","Nugroho, Branindityo"],["dc.contributor.author","Brambach, Fabian"],["dc.contributor.author","Jenkins, Michael W."],["dc.contributor.author","Pangle, Robert"],["dc.contributor.author","Stiegler, Christian"],["dc.contributor.author","Blei, Emanuel"],["dc.contributor.author","Cahyo, Andi Nur"],["dc.contributor.author","Irawan, Bambang"],["dc.contributor.author","Ariani, Rahmi"],["dc.contributor.author","June, Tania"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Knohl, Alexander"],["dc.contributor.author","Moyano, Fernando E."],["dc.contributor.author","Olchev, Alexander"],["dc.contributor.author","Tarigan, Suria"],["dc.contributor.author","Corre, Marife D."],["dc.contributor.orcid","0000-0002-7328-306X"],["dc.creator.author","Ali, Ashehad"],["dc.date.accessioned","2021-04-12T09:57:40Z"],["dc.date.available","2021-04-12T09:57:40Z"],["dc.date.issued","2021"],["dc.description.abstract","Rainforest conversion to woody croplands impacts the carbon cycle via ecophysiological processes such as photosynthesis and autotrophic respiration. Changes in the carbon cycle associated with land-use change can be estimated through Land Surface Models (LSMs). The accuracy of carbon flux estimation in carbon fluxes associated with land-use change has been attributed to uncertainties in the model parameters affecting photosynthetic activity, which is a function of both carboxylation capacity (Vcmax) and electron transport capacity (Jmax). In order to reduce such uncertainties for common tropical woody crops and trees, in this study we measured Vcmax25 (Vcmax standardized to 25 °C), Jmax25 (Jmax standardized to 25 °C) and light-saturated photosynthetic capacity (Amax) of Elaeis guineensis Jacq. (oil palm), Hevea brasiliensis (rubber tree), and two native tree species, Eusideroxylon zwageri and Alstonia scholaris, in a converted landscape in Jambi province (Sumatra, Indonesia) at smallholder plantations. We considered three plantations; a monoculture rubber, a monoculture oil palm, and an agroforestry system (jungle rubber plantation), where rubber trees coexist with some native trees. We performed measurements on leaves at the lower part of the canopy, and used a scaling method based on exponential function to scale up photosynthetic capacity related traits to the top of the canopy. At the lower part of the canopy, we found (i) high Vcmax25 values for H. brasiliensis from monoculture rubber plantation and jungle rubber plantation that was linked to a high area-based leaf nitrogen content, and (ii) low value of Amax for E. guineensis from oil palm plantation that was due to a low value of Vcmax25 and a high value of dark respiration. At the top of the canopy, Amax varied much more than Vcmax25 among different land-use types. We found that photosynthetic capacity declined fastest from the top to the lower part of the canopy in oil palm plantations. We demonstrate that photosynthetic capacity related traits measured at the lower part of the canopy can be successfully scaled up to the top of the canopy. We thus provide helpful new data that can be used to constrain LSMs that simulate land-use change related to rubber and oil palm expansion."],["dc.identifier.doi","10.3390/f12030359"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/80655"],["dc.identifier.url","https://publications.goettingen-research-online.de/handle/2/80655"],["dc.language.iso","en"],["dc.notes.intern","DeepGreen Import"],["dc.relation","SFB 990: Ökologische und sozioökonomische Funktionen tropischer Tieflandregenwald-Transformationssysteme (Sumatra, Indonesien)"],["dc.relation","SFB 990 | A | A05: Optimierung des Nährstoffmanagements in Ölpalmplantagen und Hochrechnung plot-basierter Treibhausgasflüsse auf die Landschaftsebene transformierter Regenwälder"],["dc.relation","SFB 990 | A | A07: Räumlich-zeitliche Skalierung des Einflusses von Landnutzung und Klimawandel auf Landnutzungssysteme in Indonesien"],["dc.relation","SFB 990 | B | B06: Taxonomische, funktionelle, phylogenetische und biogeographische Diversität vaskulärer Pflanzen in Regenwald-Transformationssystemen auf Sumatra (Indonesien)"],["dc.relation.doi","10.3390/f12030359"],["dc.relation.eissn","1999-4907"],["dc.relation.issn","1999-4907"],["dc.relation.orgunit","Zentrum für Biodiversität und Nachhaltige Landnutzung"],["dc.relation.orgunit","Abteilung Bioklimatologie"],["dc.rights","https://creativecommons.org/licenses/by/4.0/"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Using a Bottom-Up Approach to Scale Leaf Photosynthetic Traits of Oil Palm, Rubber, and Two Coexisting Tropical Woody Species"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["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","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"]]