Leuschner, Christoph

[["dc.bibliographiccitation.firstpage","349"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Plant and Soil"],["dc.bibliographiccitation.lastpage","369"],["dc.bibliographiccitation.volume","422"],["dc.contributor.author","Rajab, Yasmin Abou"],["dc.contributor.author","Hölscher, Dirk"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Barus, Henry"],["dc.contributor.author","Tjoa, Aiyen"],["dc.contributor.author","Hertel, Dietrich"],["dc.date.accessioned","2018-01-09T15:04:15Z"],["dc.date.available","2018-01-09T15:04:15Z"],["dc.date.issued","2018"],["dc.description.abstract","Background and Aims To increase yield, cacao is planted increasingly in unshaded monocultures, replacing a more traditional cultivation under shade. We investigated how shade tree cover and species diversity affect the root system and its dynamics. Methods In a replicated study in Sulawesi (Indonesia), we studied the fine and coarse root system down to 3 m soil depth in three modern and more traditional cacao cultivation systems: unshaded cacao monoculture (Cacao-mono), cacao under either the legume Gliricidia sepium (Cacao-Gliricidia), or a diverse (> 6 species) shade tree cover (Cacao-multi). We analysed the vertical distribution of fine, large and coarse roots as well as fine root production, turnover and morphology on the species level. Results Stand-level fine root biomass showed a doubling with increasing shade tree cover (from 206 to 432 g m−2), but a tendency for a decrease in cacao fine root biomass. The presence of Gliricidia roots seemed to shift the cacao fine roots to a more shallow distribution, while the presence of shade tree roots in the Cacao-multi systems caused a biomass reduction and relative downward shift of the cacao roots. The turnover of cacao fine roots was much higher in the Cacao-multi stands than in the other two cultivation systems, although stand-level root production remained unchanged across the three systems. According to the stable isotope signature, Gliricidia extracted water from deeper soil layers than cacao, while no soil water partitioning was observed in the Cacao-multi stands. Conclusions Our data suggest that the cacao trees altered their fine root distribution patterns in response to root competition. Both interspecific competition and root system segregation seem to play an important role in cacao agroforests with different shade tree cover."],["dc.identifier.doi","10.1007/s11104-017-3456-x"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/11617"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.status","final"],["dc.relation","SFB 990: Ökologische und sozioökonomische Funktionen tropischer Tieflandregenwald-Transformationssysteme (Sumatra, Indonesien)"],["dc.relation","SFB 990 | B | B04: Pflanzenproduktivität und Ressourcenaufteilung im Wurzelraum entlang von Gradienten tropischer Landnutzungsintensität und Baumartenvielfalt"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Effects of shade tree cover and diversity on root system structure and dynamics in cacao agroforests"],["dc.title.subtitle","The role of root competition and space partitioning"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","68"],["dc.bibliographiccitation.journal","Perspectives in Plant Ecology, Evolution and Systematics"],["dc.bibliographiccitation.lastpage","79"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Brambach, Fabian"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Tjoa, Aiyen"],["dc.contributor.author","Culmsee, Heike"],["dc.date.accessioned","2018-02-26T10:42:56Z"],["dc.date.available","2018-02-26T10:42:56Z"],["dc.date.issued","2017"],["dc.description.abstract","Explaining the diversity and distribution of tree taxa in the isolated tropical mountain forests (TMF) of the Malesian archipelago remains one of the great challenges of tropical biogeographical research. We investigated tree diversity, endemism and community composition in 13 plots of 0.24 ha between 700 and 2400 m in the TMF of Central Sulawesi’s (Indonesia) highlands and related the patterns to gradients in elevation, climate and soil properties. Special attention was paid to understorey trees with stem diameters as low as 2 cm, not exceeding 2/3 of stand canopy height. Based on extensive taxonomic work on the plots, we found that Sulawesi’s TMF flora is with 27–78 species per 0.24 ha not species-poorer than that of other Malesian islands, and vascular plant endemism is higher (22% of the species endemic to Sulawesi) than previously thought. Alpha diversity was mainly dependent on elevation and not soil factors (7 parameters tested). The alpha diversity of tree species, genera and families declined linearly with elevation, as did the number of species and genera per family, revealing higher phylogenetic clustering at lower elevations. Indicator Species Analysis and cluster analysis identified three main forest belts (sub-montane at c. 700–1400 m, lower montane at c. 1400–2000 m, upper montane at >c. 2000 m), deviating from earlier zonation concepts by separating sub-montane (rich in taxa related to the lowlands) and lower montane communities (rich in Fagaceae and Myrtaceae). With 27–51% of all tree species in a plot never found in the upper canopy, our data suggest that the guild of true understorey tree species is species-rich (estimated at c. 130 species in our region), contradicting the hypothesis that Southeast Asian tropical forests with mass-flowering trees (here: Fagaceae) are particularly poor in understorey tree species. We conclude that the mountains of Sulawesi harbour remarkably species-rich, but still understudied, TMF with a unique tree flora rich in understorey trees, which are of high conservation priority."],["dc.identifier.doi","10.1016/j.ppees.2017.06.003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/12610"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","Diversity, endemism, and composition of tropical mountain forest communities in Sulawesi, Indonesia, in relation to elevation and soil properties"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1515"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","1530"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Moser, Gerald"],["dc.contributor.author","Hölscher, Dirk"],["dc.contributor.author","Köhler, Michael"],["dc.contributor.author","Clough, Yann"],["dc.contributor.author","Anas, Iswandi"],["dc.contributor.author","Djajakirana, Gunawan"],["dc.contributor.author","Erasmi, Stefan"],["dc.contributor.author","Hertel, Dietrich"],["dc.contributor.author","Leitner, Daniela"],["dc.contributor.author","Leuschner, Christoph"],["dc.contributor.author","Michalzik, Beate"],["dc.contributor.author","Propastin, Pavel"],["dc.contributor.author","Tjoa, Aiyen"],["dc.contributor.author","van Straaten, Oliver"],["dc.date.accessioned","2017-08-25T10:13:31Z"],["dc.date.accessioned","2020-05-11T13:19:25Z"],["dc.date.available","2017-08-25T10:13:31Z"],["dc.date.available","2020-05-11T13:19:25Z"],["dc.date.issued","2010"],["dc.description.abstract","Agroforestry systems may play a critical role in reducing the vulnerability of farmers' livelihood to droughts as tree-based systems provide several mechanisms that can mitigate the impacts from extreme weather events. Here, we use a replicated throughfall reduction experiment to study the drought response of a cacao/Gliricidia stand over a 13-month period. Soil water content was successfully reduced down to a soil depth of at least 2.5 m. Contrary to our expectations we measured only relatively small nonsignificant changes in cacao (−11%) and Gliricidia (−12%) sap flux densities, cacao leaf litterfall (+8%), Gliricidia leaf litterfall (−2%), soil carbon dioxide efflux (−14%), and cacao yield (−10%) during roof closure. However, cacao bean yield in roof plots was substantially lower (−45%) compared with control plots during the main harvest following the period when soil water content was lowest. This indicates that cacao bean yield was more sensitive to drought than other ecosystem functions. We found evidence in this agroforest that there is complementary use of soil water resources through vertical partitioning of water uptake between cacao and Gliricidia. This, in combination with acclimation may have helped cacao trees to cope with the induced drought. Cacao agroforests may thus play an important role as a drought-tolerant land use in those (sub-) tropical regions where the frequency and severity of droughts is projected to increase."],["dc.identifier.doi","10.1111/j.1365-2486.2009.02034.x"],["dc.identifier.gro","3150086"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6815"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1354-1013"],["dc.subject","cacao yield; CO2 efflux; fine root biomass; leaf litterfall; plant water uptake; sap flux; shade trees; soil water; throughfall reduction"],["dc.title","Effects of an experimental drought on the functioning of a cacao agroforestry system, Sulawesi, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]