Schwendenmann, Luitgard

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Geoderma"],["dc.bibliographiccitation.lastpage","11"],["dc.bibliographiccitation.volume","138"],["dc.contributor.author","Kleber, Markus"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Rößner, Jenny"],["dc.contributor.author","Jahn, Reinhold"],["dc.date.accessioned","2017-09-07T11:54:54Z"],["dc.date.available","2017-09-07T11:54:54Z"],["dc.date.issued","2006"],["dc.description.abstract","Halloysite and gibbsite, although known to require quite different conditions for their formation, commonly occur together in the same horizon in oxisols derived from andesitic parent materials in tropical Costa Rica. We selected two soils of similar parent material, but of different ages and soil moisture regimes to identify possible clues to the coexistence of these two minerals. We employed selective dissolution procedures, X-ray fluorescence analysis and X-ray diffraction on field moist and air dry bulk soil samples to investigate how mineralogy changes with depth. We further separated the size fraction < 2 μm by means of sedimentation after organic matter and iron oxide removal to obtain more specific information on the phyllosilicate mineralogy of the clay size fraction.We found both soils to be depleted of primary minerals and pedogenesis to have progressed to advanced weathering stages particularly in the subsoils. Gibbsite XRD signal intensities were linearly and significantly related to weathering indices, corroborating the residual nature of gibbsite as an endproduct of weathering processes. The Si-bearing quartz and kaolinite-group minerals were enriched in the topsoils, indicating (i) their independence from a primary mineral Si source and (ii) the existence of a mechanism capable of protecting them against the continuous tropical weathering pressure. As we found no indications for retrospective additions of soil material through mass movement or aeolian additions, we believe a vegetation dependent, biological pumping mechanism to be the most plausible explanation for the presence of silica bearing minerals in the La Selva topsoils.The vertical distribution of 1.0 nm halloysite and its accumulation in the lower reaches of the wetter alluvial soil suggest that this metastable mineral forms as a result of Si enrichment where the residence time of the pore water is long enough to allow for Si concentrations to exceed the halloysite precipitation threshold. Taken together, our evidence indicates gibbsite in the La Selva soils to be the endproduct of intense tropical weathering, while the presence of hydrated halloysite seems to have mainly kinetic reasons and is most probably coupled to the contemporary soil moisture regime."],["dc.identifier.doi","10.1016/j.geoderma.2006.10.004"],["dc.identifier.gro","3150140"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6871"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.relation.issn","0016-7061"],["dc.subject","Halloysite; Gibbsite; Allophane; X-ray diffraction; Silicon cycling; Tropical soils; Rain forest"],["dc.title","Halloysite versus gibbsite: Silicon cycling as a pedogenetic process in two lowland neotropical rain forest soils of La Selva, Costa Rica"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","111"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Biogeochemistry"],["dc.bibliographiccitation.lastpage","128"],["dc.bibliographiccitation.volume","64"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Brenes, Tania"],["dc.contributor.author","O'Brien, Joseph J."],["dc.contributor.author","Mackensen, Jens"],["dc.date.accessioned","2017-09-07T11:43:43Z"],["dc.date.available","2017-09-07T11:43:43Z"],["dc.date.issued","2003"],["dc.description.abstract","Our objectives were to quantify and compare soil CO2 efflux of two dominant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental factors on CO2 release. We measured soil CO2 efflux from eight permanent soil chambers on six Oxisol sites. Three sites were developed on old river terraces (‘old alluvium’) and the other three were developed on old lava flows (‘residual’). At the same time we measured soil CO2 concentrations, soil water content and soil temperature at various depths in 6 soil shafts (3 m deep). Between ‘old alluvium’ sites, the two-year average CO2 flux rates ranged from 117.3 to 128.9 mg C m−2 h−1. Significantly higher soil CO2 flux occurred on the ‘residual’ sites (141.1 to 184.2 mg C m−2 h−1). Spatial differences in CO2 efflux were related to fine root biomass, soil carbon and phosphorus concentration but also to soil water content. Spatial variability in CO2 storage was high and the amount of CO2 stored in the upper and lower soil profile was different between ‘old alluvial’ and ‘residual’ sites. The major factor identified for explaining temporal variations in soil CO2 efflux was soil water content. During periods of high soil water content CO2 emission decreased, probably due to lower diffusion and CO2 production rates. During the 2-year study period inter-annual variation in soil CO2 efflux was not detected."],["dc.identifier.doi","10.1023/a:1024941614919"],["dc.identifier.gro","3150216"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6956"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0168-2563"],["dc.subject","CO 2 efflux; Neotropical rain forest; Seasonality; Soil CO 2 storage; Soil temperature; Soil water content"],["dc.title","Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, La Selva, Costa Rica"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2218"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","2229"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Sotta, Eleneide Doff"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Guimãres, Brenda Rocha"],["dc.contributor.author","Paixão, Rosiene Keila"],["dc.contributor.author","Ruivo, Maria de Lourdes P."],["dc.contributor.author","Lola da Costa, Antonio Carlos"],["dc.contributor.author","Meir, Patrick"],["dc.date.accessioned","2017-09-07T11:54:57Z"],["dc.date.available","2017-09-07T11:54:57Z"],["dc.date.issued","2007"],["dc.description.abstract","In the next few decades, climate of the Amazon basin is expected to change, as a result of deforestation and rising temperatures, which may lead to feedback mechanisms in carbon (C) cycling that are presently unknown. Here, we report how a throughfall exclusion (TFE) experiment affected soil carbon dioxide (CO2) production in a deeply weathered sandy Oxisol of Caxiuanã (Eastern Amazon). Over the course of 2 years, we measured soil CO2 efflux and soil CO2 concentrations, soil temperature and moisture in pits down to 3 m depth. Over a period of 2 years, TFE reduced on average soil CO2 efflux from 4.3±0.1 μmol CO2 m−2 s−1 (control) to 3.2±0.1 μmol CO2 m−2 s−1 (TFE). The contribution of the subsoil (below 0.5 m depth) to the total soil CO2 production was higher in the TFE plot (28%) compared with the control plot (17%), and it did not differ between years. We distinguished three phases of drying after the TFE was started. The first phase was characterized by a translocation of water uptake (and accompanying root activity) to deeper layers and not enough water stress to affect microbial activity and/or total root respiration. During the second phase a reduction in total soil CO2 efflux in the TFE plot was related to a reduction of soil and litter decomposers activity. The third phase of drying, characterized by a continuing decrease in soil CO2 production was dominated by a water stress-induced decrease in total root respiration. Our results contrast to results of a drought experiment on clay Oxisols, which may be related to differences in soil water retention characteristics and depth of rooting zone. These results show that large differences exist in drought sensitivity among Amazonian forest ecosystems, which primarily seem to be affected by the combined effects of texture (affecting water holding capacity) and depth of rooting zone."],["dc.identifier.doi","10.1111/j.1365-2486.2007.01416.x"],["dc.identifier.gro","3150157"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6890"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1354-1013"],["dc.title","Effects of an induced drought on soil carbon dioxide (CO2) efflux and soil CO2 production in an Eastern Amazonian rainforest, Brazil"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1171"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","1184"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Veldkamp, Edzo"],["dc.contributor.author","Becker, Anja"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Clark, Deborah A."],["dc.contributor.author","Schulte-Bisping, Hubert"],["dc.date.accessioned","2017-09-07T11:54:55Z"],["dc.date.available","2017-09-07T11:54:55Z"],["dc.date.issued","2003"],["dc.description.abstract","Contrary to large areas in Amazonia of tropical moist forests with a pronounced dry season, tropical wet forests in Costa Rica do not depend on deep roots to maintain an evergreen forest canopy through the year. At our Costa Rican tropical wet forest sites, we found a large carbon stock in the subsoil of deeply weathered Oxisols, even though only 0.04–0.2% of the measured root biomass (>2 mm diameter) to 3 m depth was below 2 m. In addition, we demonstrate that 20% or more of this deep soil carbon (depending on soil type) can be mobilized after forest clearing for pasture establishment. Microbial activity between 0.3 and 3 m depth contributed about 50% to the microbial activity in these soils, confirming the importance of the subsoil in C cycling. Depending on soil type, forest clearing for pasture establishment led from no change to a slight addition of carbon in the topsoil (0–0.3 m depth). However, this effect was countered by a substantial loss of C stocks in the subsoil (1–3 m depth). Our results show that large stocks of relatively labile carbon are not limited to areas with a prolonged dry season, but can also be found in deeply weathered soils below tropical wet forests. Forest clearing in such areas may produce unexpectedly high C losses from the subsoil."],["dc.identifier.doi","10.1046/j.1365-2486.2003.00656.x"],["dc.identifier.gro","3150152"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6884"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1354-1013"],["dc.subject","Costa Rica; deforestation; land-use change; microbial activity; pasture; soil organic carbon; tropical rain forest"],["dc.title","Substantial labile carbon stocks and microbial activity in deeply weathered soils below a tropical wet forest"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","339"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Ecosystems"],["dc.bibliographiccitation.lastpage","351"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Schwendenmann, Luitgard"],["dc.contributor.author","Veldkamp, Edzo"],["dc.date.accessioned","2017-09-07T11:54:55Z"],["dc.date.available","2017-09-07T11:54:55Z"],["dc.date.issued","2005"],["dc.identifier.doi","10.1007/s10021-003-0088-1"],["dc.identifier.gro","3150144"],["dc.identifier.pmid","26811110"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6876"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.relation.issn","1432-9840"],["dc.title","The Role of Dissolved Organic Carbon, Dissolved Organic Nitrogen, and Dissolved Inorganic Nitrogen in a Tropical Wet Forest Ecosystem"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1878"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Global Change Biology"],["dc.bibliographiccitation.lastpage","1893"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Schwendenmann, L."],["dc.contributor.author","Veldkamp, E."],["dc.date.accessioned","2017-09-07T11:43:38Z"],["dc.date.available","2017-09-07T11:43:38Z"],["dc.date.issued","2006"],["dc.description.abstract","Currently, it is unknown what role tropical forest soils will play in the future global carbon cycle under higher temperatures. Many tropical forests grow on deeply weathered soils and although it is generally accepted that soil carbon decomposition increases with higher temperatures, it is not known whether subsurface carbon pools are particularly responsive to increasing soil temperatures. Carbon dioxide (CO2) diffusing out of soils is an important flux in the global carbon. Although soil CO2 efflux has been the subject of many studies in recent years, it remains difficult to deduct controls of this flux because of the different sources that produce CO2 and because potential environmental controls like soil temperature and soil moisture often covary. Here, we report results of a 5-year study in which we measured soil CO2 production on two deeply weathered soil types at different depths in an old-growth tropical wet forest in Costa Rica. Three sites were developed on old river terraces (old alluvium) and the other three were developed on old lava flows (residual). Annual soil CO2 efflux varied between 2.8–3.6 μmol CO2-C m−2 s−1 (old alluvium) and 3.4–3.9 μmol CO2-C m−2 s−1 (residual). More than 75% of the CO2 was produced in the upper 0.5 m (including litter layer) and less than 7% originated from the soil below 1 m depth. This low contribution was explained by the lack of water stress in this tropical wet forest which has resulted in very low root biomass below 2 m depth. In the top 0.5 m CO2 production was positively correlated with both temperature and soil moisture; between 0.6 and 2 m depth CO2 production correlated negatively with soil moisture in one soil and positively with photosynthetically active radiation in the other soil type. Below 2 m soil CO2 production strongly increased with increasing temperature. In combination with reduced tree growth that has been shown for this ecosystem, this would be a strong positive feedback to ecosystem warming."],["dc.identifier.doi","10.1111/j.1365-2486.2006.01235.x"],["dc.identifier.gro","3150194"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/6932"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.relation.issn","1354-1013"],["dc.subject","carbon dioxide production;Costa Rica;gas diffusion;interannual variation;La Selva;soil CO2 concentration;soil moisture;soil respiration;soil temperature;tropical rain forest"],["dc.title","Long-term CO2 production from deeply weathered soils of a tropical rain forest: evidence for a potential positive feedback to climate warming"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["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"]]