Browsing by Author "Charman, DJ"

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    Bog burst in the eastern Netherlands triggered by the 2.8 kyr BP climate event
    (Sage Journals, 2014-11) van Geel, B; Heijnis, H; Charman, DJ; Thompson, G; Engels, S
    The nature and cause of the so-called 2.8 kyr BP event have been a subject of much debate. Peat sequences have provided much of the evidence for this event, but the process link between climate and peatland response is not well understood. Multiproxy, high-resolution analysis of a core from Bargerveen in the eastern Netherlands based on pollen, non-pollen palynomorphs, testate amoebae and geochemistry identified an abrupt shift from relatively dry to extremely wet conditions. Radiocarbon-based wiggle-match dating (WMD) and biostratigraphy based on the pollen record show that this shift in local hydrology occurred around 2800 cal. yr BP. We interpret an erosional hiatus lasting up to 950 years immediately prior to this, as the effect of a bog burst after excessive rainfall. This phenomenon was not limited to our sampling location but occurred over a large part of the former Bargerveen. Peat at the hiatus contains microfossils that reflect temporary eutrophication as a consequence of local fires and secondary decomposition because of increased drainage after the erosion event. Our data show how detailed multiproxy analyses can elucidate the past response of peatlands to changing climate and suggest that the climatic change in northwest Europe at this time caused major non-linear disruption to these ecosystems. © 2014, © SAGE Publications.
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    Bog burst in the eastern Netherlands triggered by the 2.8 kyr BP climate event
    (University of New South Wales and Australian Nuclear Science and Technology Organisation, 2015-07-09) Heijnis, H; van Geel, B; Charman, DJ; Thompson, G; Engels, S
    Not provided to the ANSTO Library.
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    Insights for restoration: reconstructing the long-term responses, resilience and recovery time of vegetation, hydrology and peat condition to fire events in the Sebangau peatland, Central Kalimantan.
    (Australasian Quaternary Association Inc., 2022-12-06) Mohamed, R; Khairun, N; Moss, PT; Jacobsen, GE; Gallego-Sala, A; Charman, DJ; Yulianti, N
    The palaeoecological and geochemical analysis of peat in the Natural Laboratory Peat-swamp Forest (NLPSF) has been used to identify the drivers of fire severity (FS) events and the associated responses, resilience and recovery time of this peatland system to aid in future restoration efforts in the Sebangau Peatland National Park (SPNP). From 4500 years BP to present, fire events have increased in severity and the drivers of FS included changes to sea level, increased frequency of El Niño events, increased biomass, and anthropogenic-driven degradation. The increased FS along with changes to the hydrology and peat condition over time have resulted in a vegetation turnover from mixed of peat forest and other vegetation types during the mid to late Holocene (4500 to 1201 years BP), to peat swamp forest (PSF) during the following ~800 years (1200 to 378 BP), lowland vegetation mixed with swamp forest (LMS) and open vegetation (OV) for the period between 377 and 134 years BP and finally, freshwater swamp forest (FSF) and OV in the last ~200 years (133 to -54 years BP) (Fig 1). From the Principal Component Analysis (PCA) and Generalised Linear Model (GLM), the changes to dominant vegetation types were due to changes in local hydrological conditions, as well as the fertilising effect from the combustion of organic matter (i.e. release of N and other minerals) and loss of soluble peat component during fire events. This information, together with the thresholds and lags of the responses, provided the following restoration insights: 1) Vegetation species have different fire intensity tolerances and transition from PSF to LMS and OV required a higher threshold with recovery time of approximately 70 to 80 years; 2) PSF expanded with higher peat nutrients (i.e. TN) and required wet peat environments compared to FSF and LMS but some PSF species (i.e. Eurya and Ilex) were able to cope with slightly drier peat conditions ; 4) Future revegetation in SPNP can focus on species such as Araceae, Restionaceae Myriophyllum, and Ficus as they were able to withstand high FS, less acidic and minimally wet conditions, while sustaining carbon accumulation in degraded tropical peatlands.