1,721,073 research outputs found
The future of the past: Applications of paleoecological findings in peatland restoration in Indonesia
No full textTwo-step vegetation response to enhanced precipitation in Northeast Brazil during Heinrich event 1
No full textHigh resolution palynological and geochemical data of sediment core GeoB 3910-2 (located offshore Northeast Brazil) spanning the period between 19 600 and 14 500 calibrated year bp (19.6-14.5 ka) show a land-cover change in the catchment area of local rivers in two steps related to changes in precipitation associated with Heinrich Event 1 (H1 stadial). At the end of the last glacial maximum, the landscape in semi-arid Northeast Brazil was dominated by a very dry type of caatinga vegetation, mainly composed of grasslands with some herbs and shrubs. After 18 ka, considerably more humid conditions are suggested by changes in the vegetation and by C(org) and C/N data indicative of fluvial erosion. The caatinga became wetter and along lakes and rivers, sedges and gallery forest expanded. The most humid period was recorded between 16.5 and 15 ka, when humid gallery (and floodplain) forest and even small patches of mountainous Atlantic rain forest occurred together with dry forest, the latter being considered as a rather lush type of caatinga vegetation. During this humid phase erosion decreased as less lithogenic material and more organic terrestrial material were deposited on the continental slope of northern Brazil. After 15 ka arid conditions returned. During the humid second phase of the H1 stadial, a rich variety of landscapes existed in Northeast Brazil and during the drier periods small pockets of forest could probably survive in favorable spots, which would have increased the resilience of the forest to climate change
Late Holocene ENSO-related fire impact on vegetation, nutrient status and carbon accumulation of peatlands in Jambi, Sumatra, Indonesia
No full textHigh-resolution multi-proxy reconstruction of environmental changes in coastal waters of the Java Sea, Indonesia, during the late Holocene
No full textIntertwined effects of climate and land use change on environmental dynamics and carbon accumulation in a mangrove‐fringed coastal lagoon in Java, Indonesia
No full textThe identification and quantification of natural carbon (C) sinks is critical to global climate change mitigation efforts. Tropical coastal wetlands are considered important in this context, yet knowledge of their dynamics and quantitative data are still scarce. In order to quantify the C accumulation rate and understand how it is influenced by land use and climate change, a palaeoecological study was conducted in the mangrove‐fringed Segara Anakan Lagoon (SAL) in Java, Indonesia. A sediment core was age‐dated and analyzed for its pollen and spore, elemental and biogeochemical compositions. The results indicate that environmental dynamics in the SAL and its C accumulation over the past 400 years were controlled mainly by climate oscillations and anthropogenic activities. The interaction of these two factors changed the lagoon's sediment supply and salinity, which consequently altered the organic matter composition and deposition in the lagoon. Four phases with varying climates were identified. While autochthonous mangrove C was a significant contributor to carbon accumulation in SAL sediments throughout all four phases, varying admixtures of terrestrial C from the hinterland also contributed, with natural mixed forest C predominating in the early phases and agriculture soil C predominating in the later phases. In this context, climate‐related precipitation changes are an overarching control, as surface water transport through rivers serves as the “delivery agent” for the outcomes of the anthropogenic impact in the catchment area into the lagoon. Amongst mangrove‐dominated ecosystems globally, the SAL is one of the most effective C sinks due to high mangrove carbon input in combination with a high allochthonous carbon input from anthropogenically enhanced sediment from the hinterland and increased preservation. Given the substantial C sequestration capacity of the SAL and other mangrove‐fringed coastal lagoons, conservation and restoration of these ecosystems is vitally important for climate change mitigation
Dynamiken von Nährstoffen und organischem Material in einem von menschlichen Aktivitäten beeinflussten makrotidalen Ästuar, das Nanliu Ästuar, Süd-China
No full textAnthropogenic nutrients, mainly from agriculture but also from aquaculture, cause eutrophication. Negative effects include ecosystem degradation via oxygen depletion following organic matter decomposition. Mangrove forests are potential nutrient filters. This study investigates land-derived material inputs into coastal waters of southern China and assesses the effect of mangroves. Nanliu River and Lianzhou Bay comprise multiple human impacts. Transformations and fates of nutrients and organic matter were investigated by biogeochemical field and laboratory methods. The role of mangroves was assessed by field measurements, incubation experiments, and model calculations. Results show that land-use in river catchments dominantly contributes to eutrophication in coastal waters. This is a regional rather than local conservation issue. Natural factors do not sufficiently reduce nutrients, making improved nutrient management the only option preventing eutrophication
Asynchronous terrestrial and marine signals of climate change during Heinrich events
No full textTropical regions have been reported to play a key role in climate dynamics. To date, however, there are uncertainties in the timing and the amplitude of the response of tropical ecosystems to millennial-scale climate change. We present evidence of an asynchrony between terrestrial and marine signals of climate change during Heinrich events preserved in marine sediment cores from the Brazilian continental margin. The inferred time lag of about 1000 to 2000 years is much larger than the ecological response to recent climate change and appears to be related to the nature of hydrological changes. The recent increase in extreme climatic events, particularly in tropical regions, is thought by many to be a precursor of climate change. High-resolution investigations of past climate oscillations have found that changes between climate modes (warm versus cold and dry versus wet) can occur within decade
Resilience of a peatland in Central Sumatra, Indonesia to past anthropogenic disturbance: Improving conservation and restoration designs using palaeoecology
No full textMultibeam bathymetry raw data (EM 120 echosounder entire dataset) of RV SONNE during cruise SO184/3
No full textMultibeam bathymetry raw data using the ship's own Kongsberg (Simrad) EM 120 multibeam echosounder was continuously recorded during RV SONNE cruise SO184/3. Data was recorded on 20 days between 2005-08-22 and 2005-09-10. This dataset contains an elongated transit survey south of the islands of Indonesia. Data covers parts of the continental shelf and continental slope. The approximate average depth of the entire dataset is around 2500m.
The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. No ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus no SVP files are added to this dataset. However, data analysis of the multibeam raw data revealed that SVP has been changed during the survey.
This publication is conducted within the efforts of the German Marine Research Alliance in the core area 'Data management and Digitalization' (Deutsche Allianz Meeresforschung, DAM).
Data are unprocessed and therefore contains incorrect depth measurements (artifacts) without further processing. Note that refraction errors can be expected due to the lack of proper SVP. Overall, it appears that the data quality is rather good since the gridded hillshade data showed relatively few obstacles.
Data can be processed e.g. with the open source software package MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, http://www.mbari.org/products/research-software/mb-system/, 2022)
Environmental dynamics and carbon accumulation rate of a tropical peatland in Central Sumatra, Indonesia
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