Guillaume, Thomas

[["dc.bibliographiccitation.firstpage","49"],["dc.bibliographiccitation.journal","Ecological Indicators"],["dc.bibliographiccitation.lastpage","57"],["dc.bibliographiccitation.volume","67"],["dc.contributor.author","Guillaume, Thomas"],["dc.contributor.author","Maranguit, Deejay"],["dc.contributor.author","Murtilaksono, Kukuh"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2018-11-07T10:10:33Z"],["dc.date.available","2018-11-07T10:10:33Z"],["dc.date.issued","2016"],["dc.description.abstract","Tropical forest conversion to agricultural land leads to a strong decrease of soil organic carbon (SOC) stocks. While the decrease of the soil C sequestration function is easy to measure, the impacts of SOC losses on soil fertility remain unclear. Especially the assessment of the sensitivity of other fertility indicators as related to ecosystem services suffers from a lack of clear methodology. We developed a new approach to assess the sensitivity of soil fertility indicators and tested it on biological and chemical soil properties affected by rainforest conversion to plantations. The approach is based on (non-)linear regressions between SOC losses and fertility indicators normalized to their level in a natural ecosystem. Biotic indicators (basal respiration, microbial biomass, acid phosphatase), labile SOC pools (dissolved organic carbon and light fraction) and nutrients (total N and available P) were measured in Ah horizons from rainforests, jungle rubber, rubber (Hevea brasiliensis) and oil palm (Elaeis guineensis) plantations located on Sumatra. The negative impact of land-use changes on all measured indicators increased in the following sequence: forest < jungle rubber < rubber < oil palm. The basal respiration, microbial biomass and nutrients were resistant to SOC losses, whereas the light fraction was lost stronger than SOC. Microbial C use efficiency was independent on land use. The resistance of C availability for microorganisms to SOC losses suggests that a decrease of SOC quality was partly compensated by litter input and a relative enrichment by nutrients. However, the relationship between the basal respiration and SOC was non-linear; i.e. negative impact on microbial activity strongly increased with SOC losses. Therefore, a small decrease of C content under oil palm compared to rubber plantations yielded a strong drop in microbial activity. Consequently, management practices mitigating SOC losses in oil palm plantations would strongly increase soil fertility and ecosystem stability. We conclude that the new approach enables quantitatively assessing the sensitivity and resistance of diverse soil functions to land-use changes and can thus be used to assess resilience of agroecosystems with various use intensities. (C) 2016 Elsevier Ltd. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [CRC990]"],["dc.identifier.doi","10.1016/j.ecolind.2016.02.039"],["dc.identifier.isi","000388785300006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/39877"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 990: Ökologische und sozioökonomische Funktionen tropischer Tieflandregenwald-Transformationssysteme (Sumatra, Indonesien)"],["dc.relation","SFB 990 | A | A04: Carbon stock, turnover and functions in heavily weathered soils under lowland rainforest transformation systems"],["dc.relation.issn","1872-7034"],["dc.relation.issn","1470-160X"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Sensitivity and resistance of soil fertility indicators to land-use changes: New concept and examples from conversion of Indonesian rainforest to plantations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","385"],["dc.bibliographiccitation.journal","CATENA"],["dc.bibliographiccitation.lastpage","393"],["dc.bibliographiccitation.volume","149"],["dc.contributor.author","Maranguit, Deejay"],["dc.contributor.author","Guillaume, Thomas"],["dc.contributor.author","Kuzyakov, Yakov"],["dc.date.accessioned","2018-11-07T10:28:12Z"],["dc.date.available","2018-11-07T10:28:12Z"],["dc.date.issued","2017"],["dc.description.abstract","Deforestation and land-use change in tropics have increased over the past decades, driven by the demand for agricultural products. Although phosphorus (P) is one of the main limiting nutrients for agricultural productivity in the tropics, the effect of land-use change on P availability remains unclear. The objective was to assess the impacts of land-use change on soil inorganic and organic P fractions of different availability (Hedley sequential fractionation) and on P stocks in highly weathered tropical soils. We compared the P availability under extensive land-use (rubber agroforest) and intensive land-use with moderate fertilization (rubber monoculture plantations) or high fertilization (oil palm monoculture plantations) in Indonesia. The P stock was dominated by inorganic forms (60 to 85%) in all land-use types. Fertilizer application increased easily-available inorganic P (i.e., H2O-Pi, NaHCO3-Pi) in intensive rubber and oil palm plantations compared to rubber agroforest However, the easily-available organic P (NaHCO3-extractable Po) was reduced by half under oil palm and rubber. The decrease of moderately available and non-available P in monoculture plantation means that fertilization maintains only the short-term soil fertility that is not sustainable in the long run due to the depletion of P reserves. The mechanisms of this P reserve depletion are: 1) soil erosion (here assessed by C/P ratio), 2) mineralization of soil organic matter (SOM) and 3) P export with yield products. Easily-available P fractions (i.e., H2O-Pi, NaHCO3-Pi and Po) and total organic P were strongly positively correlated with carbon content, suggesting that SOM plays a key role in maintaining P availability. Ecologically based management is therefore necessary to mitigate SOM losses and thus increase the sustainability of agricultural production in P-limited, highly weathered tropical soils. (C) 2016 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.catena.2016.10.010"],["dc.identifier.isi","000390733300038"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43373"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation","SFB 990: Ökologische und sozioökonomische Funktionen tropischer Tieflandregenwald-Transformationssysteme (Sumatra, Indonesien)"],["dc.relation","SFB 990 | A | A04: Carbon stock, turnover and functions in heavily weathered soils under lowland rainforest transformation systems"],["dc.relation.issn","1872-6887"],["dc.relation.issn","0341-8162"],["dc.subject.gro","sfb990_journalarticles"],["dc.title","Land-use change affects phosphorus fractions in highly weathered tropical soils"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]