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.artnumber","PII S0378-1127(01)00814-3"],["dc.bibliographiccitation.firstpage","105"],["dc.bibliographiccitation.issue","1-3"],["dc.bibliographiccitation.journal","Forest Ecology and Management"],["dc.bibliographiccitation.lastpage","123"],["dc.bibliographiccitation.volume","173"],["dc.contributor.author","Worbes, Martin"],["dc.contributor.author","Staschel, R."],["dc.contributor.author","Roloff, A."],["dc.contributor.author","Junk, W. J."],["dc.date.accessioned","2018-11-07T10:40:59Z"],["dc.date.available","2018-11-07T10:40:59Z"],["dc.date.issued","2003"],["dc.description.abstract","In a semi-deciduous natural forest stand in Cameroon a forest inventory and increment estimations on all trees with a diameter above 10 cm were carried out in an area of 1 ha. The stand is dominated by Triplochiton scleroxylon and is a part of a forest type which is widely distributed in West Africa. The existence of annual rings in the wood of trees was proven by radiocarbon dating and tree ring analysis. The oldest tree (Celtis zenkeri) of the stand was 220 years old. The age class between 41 and 60 years is the strongest in number of individuals. Trees with an age of more than 120 years were found exclusively in the storey of the emergents. The age of the trees correlates very weakly with the diameter and the height. The mean diameter growth rates vary between 0.2 cm per year in understorey tree species and 0.82 cm per year in emergent species. The major timber species (T scleroxylon) reaches in mean the minimum felling diameter of 80 cm within 90 years. According to their age and height distribution together with the wood density, we distinguished three major types of life strategies of species cohorts. Species with high wood density and low increment rates in all age classes are generally restricted to the understorey. Species with exclusively old individuals, low or moderate wood densities and high increment rates are restricted to the upper storey and can be classified as long-living pioneers (T scleroxylon). Finally, species with moderate or high wood density, some old individuals in the upper storey and many recruits in the lower canopy can be defined as mature forest trees or trees of the future (Nesogordonia papaverifera, Sterculia rhinopetala). These findings lead to the assumption that the investigated stand can be classified as a very late secondary stand in transition to a mature forest. (C) 2002 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0378-1127(01)00814-3"],["dc.identifier.isi","000180897400009"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/46434"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0378-1127"],["dc.title","Tree ring analysis reveals age structure, dynamics and wood production of a natural forest stand in Cameroon"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]