Worbes, Martin

[["dc.bibliographiccitation.firstpage","454"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Oecologia"],["dc.bibliographiccitation.lastpage","461"],["dc.bibliographiccitation.volume","145"],["dc.contributor.author","Schongart, J."],["dc.contributor.author","Piedade, Maria T. F."],["dc.contributor.author","Wittmann, F."],["dc.contributor.author","Junk, W. J."],["dc.contributor.author","Worbes, Martin"],["dc.date.accessioned","2018-11-07T10:56:31Z"],["dc.date.available","2018-11-07T10:56:31Z"],["dc.date.issued","2005"],["dc.description.abstract","Macrolobium acaciifolium (Benth.) Benth. ( Fabaceae) is a dominant legume tree species occurring at low elevations of nutrient-poor black-water (igapo) and nutrient-rich white-water floodplain forests (varzea) of Amazonia. As a consequence of the annual long-term flooding this species forms distinct annual tree rings allowing dendrochronological analyses. From both floodplain types in Central Amazonia we sampled cores from 20 large canopy trees growing at identical elevations with a flood-height up to 7 m. We determined tree age, wood density (WD) and mean radial increment (MRI) and synchronized ring-width patterns of single trees to construct tree-ring chronologies for every study site. Maximum tree age found in the igapo was more than 500 years, contrary to the varzea with ages not older than 200 years. MRI and WD were significantly lower in the igapo ( MRI = 1.52 +/- 0.38 mm year(-1), WD = 0.39 +/- 0.05 g cm(-3)) than in the varzea (MRI = 2.66 +/- 0.67 mm year(-1), WD= 0.45 +/- 0.03 g cm(-3)). In both floodplain forests we developed tree-ring chronologies comprising the period 1857 - 2003 ( n= 7 trees) in the varzea and 1606 - 2003 ( n= 13 trees) in the igapo. The ring-width in both floodplain forests was significantly correlated with the length of the terrestrial phase ( vegetation period) derived from the daily recorded water level in the port of Manaus since 1903. In both chronologies we found increased wood growth during El Nino events causing negative precipitation anomalies and a lower water discharge in Amazonian rivers, which leads to an extension of the terrestrial phase. The climate signal of La Nina was not evident in the dendroclimatic proxies."],["dc.identifier.doi","10.1007/s00442-005-0147-8"],["dc.identifier.isi","232401800012"],["dc.identifier.pmid","16025354"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50033"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0029-8549"],["dc.title","Wood growth patterns of Macrolobium acaciifolium (Benth.) Benth. (Fabaceae) in Amazonian black-water and white-water floodplain forests"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","683"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","692"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Schongart, J."],["dc.contributor.author","Junk, W. J."],["dc.contributor.author","Piedade, Maria T. F."],["dc.contributor.author","Ayres, J. M."],["dc.contributor.author","Huttermann, A."],["dc.contributor.author","Worbes, Martin"],["dc.date.accessioned","2018-11-07T10:49:15Z"],["dc.date.available","2018-11-07T10:49:15Z"],["dc.date.issued","2004"],["dc.description.abstract","There is a limited knowledge about the El Nino-Southern Oscillation (ENSO) effects on the Amazon basin, the world's largest tropical rain forest and a major factor in the global carbon cycle. Seasonal precipitation in the Andean watershed annually causes a several month-long inundation of the floodplains along the Amazon River that induces the formation of annual rings in trees of the flooded forests. Radial growth of trees is mainly restricted to the nonflooded period and thus the ring width corresponds to its duration. This allows the construction of a tree-ring chronology of the long-living hardwood species Piranhea trifoliata Baill. (Euphorbiaceae). El Nino causes anomalously low precipitation in the catchment that results in a significantly lower water discharge of the Amazon River and consequently in an extension of the vegetation period. In those years tree rings are significantly wider. Thus the tree-ring record can be considered as a robust indicator reflecting the mean climate conditions of the whole Western Amazon basin. We present a more than 200-year long chronology, which is the first ENSO-sensitive dendroclimatic proxy of the Amazon basin and permits the dating of preinstrumental El Nino events. Time series analyses of our data indicate that during the last two centuries the severity of El Nino increased significantly."],["dc.identifier.doi","10.1111/j.1529-8817.2003.00754.x"],["dc.identifier.isi","000221421600011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48384"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Blackwell Publishing Ltd"],["dc.relation.issn","1354-1013"],["dc.title","Teleconnection between tree growth in the Amazonian floodplains and the El Nino-Southern Oscillation effect"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1139"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","1150"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Schongart, J."],["dc.contributor.author","Orthmann, B."],["dc.contributor.author","Hennenberg, K. J."],["dc.contributor.author","Porembski, S."],["dc.contributor.author","Worbes, Martin"],["dc.date.accessioned","2018-11-07T09:35:45Z"],["dc.date.available","2018-11-07T09:35:45Z"],["dc.date.issued","2006"],["dc.description.abstract","Most tropical regions are facing historical difficulties of generating biologically reconstructed long-term climate records. Dendrochronology (tree-ring studies) is a powerful tool to develop high-resolution and exactly dated proxies for climate reconstruction. Owing to the seasonal variation in rainfall we expected the formation of annual tree rings in the wood of tropical West African tree species. In the central-western part of Benin (upper Oueme catchment, UOC) and in northeastern Ivory Coast (Comoe National Park, CNP) we investigated the relationship between climate (precipitation, sea surface temperature (SST)) and tree rings and show their potential for climate reconstruction. Wood samples of almost 200 trees belonging to six species in the UOC and CNP served to develop climate-sensitive ring-width chronologies using standard dendrochronological techniques. The relationship between local precipitation, monthly SST anomalies in the Gulf of Guinea, El Nino- Southern Oscillation (ENSO) and ring-width indices was performed by simple regression analyses, two sample tests and cross-spectral analysis. A low-pass filter was used to highlight the decadal variability in rainfall of the UOC site. All tree species showed significant relationships with annual precipitation proving the existence of annual tree rings. ENSO signals could not be detected in the ring-width patterns. For legume tree species at the UOC site significant relationships could be found between SST anomalies in the Gulf of Guinea indicating correlations at periods of 5.1-4.1 and 2.3 years. Our findings accurately show the relationship between tree growth, local precipitation and SST anomalies in the Gulf of Guinea possibly associated with worldwide SST patterns. A master chronology enabled the reconstruction of the annual precipitation in the UOC to the year 1840. Time series analysis suggest increasing arid conditions during the last 160 years which may have large impacts on the hydrological cycles and consequently on the ecosystem dynamics and the development of socio-economic cultures and sectors in the Guinea-Congolian/Sudanian region."],["dc.identifier.doi","10.1111/j.1365-2486.2006.01154.x"],["dc.identifier.isi","000238352800002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32457"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Blackwell Publishing"],["dc.relation.issn","1354-1013"],["dc.title","Climate-growth relationships of tropical tree species in West Africa and their potential for climate reconstruction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","581"],["dc.bibliographiccitation.journal","Journal of Tropical Ecology"],["dc.bibliographiccitation.lastpage","597"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Schongart, J."],["dc.contributor.author","Piedade, Maria T. F."],["dc.contributor.author","Ludwigshausen, S."],["dc.contributor.author","Horna, Viviana"],["dc.contributor.author","Worbes, Martin"],["dc.date.accessioned","2018-11-07T10:22:46Z"],["dc.date.available","2018-11-07T10:22:46Z"],["dc.date.issued","2002"],["dc.description.abstract","To study the impact of the annual long-term flooding (flood-pulse) on seasonal tree development in Amazonian floodplains, the phenology and growth in stem diameter of various tree species with different leaf-change patterns were observed over a period of 2 y. The trees of the functional ecotypes, evergreen, brevi-deciduous, deciduous and stem-succulent showed a periodic behaviour mainly triggered by the flood-pulse. Trees have high increment during the terrestrial phase. Flooding causes a shedding of some or all leaves leading to a cambial dormancy of about 2 mo and the formation of an annual ring. Studies carried out in tropical dry forests verify a strong relationship between the phenological development and the water status of the trees, strongly affected by seasonal drought. The comparison of the phenology and the diameter growth of the corresponding ecotypes in floodplain forest and a semi-deciduous forest in Venezuela shows a displacement of at least 2 mo in the periodicity, except for stem-succulent tree species. For stem-succulent trees it remains unclear which factors influence phenology and stem diameter growth."],["dc.identifier.doi","10.1017/S0266467402002389"],["dc.identifier.isi","000177349500006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42334"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Cambridge Univ Press"],["dc.relation.issn","0266-4674"],["dc.title","Phenology and stem-growth periodicity of tree species in Amazonian floodplain forests"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]