Juhrbandt, Jana

[["dc.bibliographiccitation.firstpage","245"],["dc.bibliographiccitation.issue","1-3"],["dc.bibliographiccitation.journal","Forest Ecology and Management"],["dc.bibliographiccitation.lastpage","256"],["dc.bibliographiccitation.volume","202"],["dc.contributor.author","Juhrbandt, Jana"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Hölscher, Dirk"],["dc.date.accessioned","2017-09-07T11:45:43Z"],["dc.date.available","2017-09-07T11:45:43Z"],["dc.date.issued","2004"],["dc.description.abstract","The large-scale conversion of tropical old-growth forests to other land use types may subsequently increase the area covered by secondary forests. These tropical secondary forests are dominated by early successional tree species that may have elevated stomatal conductances and transpirational water loss. We studied eight abundant tree species of the tropical moist secondary forest in Sulawesi, Indonesia, for sun leaf stomatal conductance of water vapour (gsmax) in 4–7 m tall trees and related conductance to various leaf morphological (size, specific leaf area) and chemical parameters (nutrient contents, δ13C). gsmax showed a considerable variability among the eight coexisting early successional trees (393–734 mmol m−2 s−1). With a mean of 590 mmol m−2 s−1 it was more than twice as high as the maximal conductance reported for mature late-successional trees in tropical moist forests. Among the tested leaf traits, gsmax showed the closest relation to leaf nitrogen per area and leaf size; gsmax was only weakly correlated to leaf nitrogen per unit dry mass; no correlation existed with leaf δ13C values and specific leaf area. A significant negative relationship existed between gsmax and leaf size, which could point at a reduction in leaf-specific hydraulic conductance of the leaf petiole in large leaves of tropical pioneer trees. Thus, our data indicate that the early successional tree species studied in Sulawesi are characterized by a high but relatively heterogeneous water turn-over, and that leaf size might be a good predictor for maximal stomatal conductance."],["dc.identifier.doi","10.1016/j.foreco.2004.07.021"],["dc.identifier.gro","3149077"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5723"],["dc.language.iso","en"],["dc.notes.intern","Hoelscher Crossref import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0378-1127"],["dc.title","The relationship between maximal stomatal conductance and leaf traits in eight Southeast Asian early successional tree species"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","278"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Trees"],["dc.bibliographiccitation.lastpage","285"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Hölscher, Dirk"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Bohman, Kerstin"],["dc.contributor.author","Hagemeier, Marc"],["dc.contributor.author","Juhrbandt, Jana"],["dc.contributor.author","Tjitrosemito, Soekisman"],["dc.date.accessioned","2017-09-07T11:45:38Z"],["dc.date.available","2017-09-07T11:45:38Z"],["dc.date.issued","2006"],["dc.description.abstract","In the tropics, old-growth forests are converted to other land cover types at a high rate and young secondary forest may gain in importance. Information on associated changes in leaf gas exchange and other leaf traits can be valuable for modelling biogeochemical fluxes under altered land-use patterns. We studied in situ photosynthetic parameters and stomatal conductance for water vapour in eight abundant tree species of young secondary forest and eight tree species of natural old-growth forest in Central Sulawesi, Indonesia. In sun leaves, the average maximal stomatal conductance (g smax) in the secondary forest (SF) species was 2.1 times higher than in the old-growth forest (OGF) species. Species with a high g smax reduced g s sharply when vapour pressure deficit of the air increased, whereas species with a low g smax were much less sensitive to air humidity. For area-based photosynthetic capacity (A max-area), the SF species had a 2.3 times higher average than the OGF species. For both, g smax and A max-area the variation among species was higher in the OGF than in the SF. When all tree species (n=16) are considered, species means of specific leaf area (SLA), leaf N concentration and leaf P concentration were significantly correlated with g smax and A max-area. The strong correlation between A max-area and foliar P (r 2=0.8) is remarkable as the alluvial soils in the study region are rich in nutrients. If the eight OGF species are analysed separately, the only significant correlation was observed between SLA and mass-based A max; in the SF species strong correlations were found between leaf size and A max-area and g smax. These results show that the conversion of old-growth forest to young secondary forest in Sulawesi significantly alters tree leaf gas exchange characteristics and that chemical and structural leaf traits can be used for the prediction of these changes. The best correlations between leaf gas exchange parameters and leaf traits were obtained by different traits in the SF species, the OGF species and the entire pool of studied species."],["dc.identifier.doi","10.1007/s00468-005-0040-4"],["dc.identifier.gro","3149061"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5705"],["dc.language.iso","en"],["dc.notes.intern","Hoelscher Crossref import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0931-1890"],["dc.title","Leaf gas exchange of trees in old-growth and young secondary forest stands in Sulawesi, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","157"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Tropical Ecology"],["dc.bibliographiccitation.lastpage","164"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Hölscher, Dirk"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Bohman, Kerstin"],["dc.contributor.author","Juhrbandt, Jana"],["dc.contributor.author","Tjitrosemito, S."],["dc.date.accessioned","2017-09-07T11:45:43Z"],["dc.date.available","2017-09-07T11:45:43Z"],["dc.date.issued","2004"],["dc.description.abstract","Tropical pioneer tree species are considered as a functional group characterized by a suite of ecological characteristics such as high light demand and high photosynthetic capacities. This study compared the photosynthetic characteristics of eight co-existing pioneer tree species in 3–4-y-old and about 6-m-tall secondary forest stands in Sulawesi, Indonesia. Its objectives were (1) to determine the range and interspecific variation in six photosynthetic parameters, and (2) to identify morphological and chemical leaf traits that can predict light-saturated net photosynthetic rates (on a leaf area or leaf mass basis, Amax-area or Amax-mass). Species averages of Amax-area in sun leaves ranged between 14.2 and 20.3 μmol m−2 s−1 (mean 17.5) which is high compared with literature data. Among the co-existing species, average leaf size (56–896 cm2) differed by a factor of 16, specific leaf area (SLA, 10.7–21.4 m2 kg−1) and leaf nitrogen content (19.6–33.9 g kg−1) twofold. At the species level, Amax-area was not correlated with leaf N content but decreased significantly with leaf size. Amax-mass showed a higher interspecific variation than Amax-area, and was positively correlated with SLA and leaf N content (slope: 13.4 nmol CO2 g N−1 s−1). Both, Amax-area and Amax-mass were more closely related to leaf morphological attributes than to leaf N. We conclude that the tropical pioneer tree species studied do not form a homogeneous functional group in terms of photosynthetic performance. Rather, a considerable variation in leaf morphology and nitrogen content exists, which also shows up in a substantial variation in Amax-mass and, to a lesser extent, in Amax-area."],["dc.identifier.doi","10.1017/s0266467403001251"],["dc.identifier.gro","3149063"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5707"],["dc.language.iso","en"],["dc.notes.intern","Hoelscher Crossref import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0266-4674"],["dc.title","Photosynthetic characteristics in relation to leaf traits in eight co-existing pioneer tree species in Central Sulawesi, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]