(2017) Impacts of conversion of tropical peat swamp forest to oil palm plantation on peat organic chemistry, physical properties and carbon stocks. Geoderma, 289 . pp. 36-45. ISSN 1872-6259 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/43906/1/Tonks%20et%20al.%20for %20Geoderma_18%20Oct.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the Creative Commons Attribution Non-commercial No Derivatives licence and may be reused according to the conditions of the licence. For more details see: http://creativecommons.org/licenses/by-nc-nd/2.5/ A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk greater than decomposition rates (Jauhiainen et al., 2008). 54These unique systems are valuable resources, contributing a multitude of ecosystem services. 55Above ground, tropical rainforests maintain areas of high biodiversity by providing habitats 56 for a variety of species, many of which are endemic (Posa et al. 2011; Keddy et al., 2009). 57Below ground, the sequestration of atmospheric carbon is interwoven into the fabric of the 58 ecosystem (Jauhiainen et al., 2008). An estimated 42,000 megatons of ancient carbon is 59 stored in 12% of the total land area of Southeast Asia alone, making this one of the largest 60 stores of terrestrial carbon on Earth (Wetlands International, 2014). Peat soil structure is 61 responsible for ecosystem processes by controlling hydrology, which regulates hydrological 62 features within the catchment. For example, its high organic matter content and low bulk 63 density allows peat to acts as a water reservoir, mitigating extreme conditions such as floods 64 and droughts (Huat et al., 2011;Wösten et al., 2008). 65Land use change over the past century has been a key driver of peatland degradation, with 66 conversion to agriculture and forestry, and peat extraction sites, leading to artificially lowered 67 water tables (Haddaway et al., 2014 (Hooijer et al., 2010; Couwenberg et al., 2010). 85A greater degree of peat decomposition results in loss of structure as fresh litter is first broken 86 down to fibrous hemic peat, and then, following sustained decomposition, to sapric peat 87 (Wüst et al., 2003). The progressing decomposition process alters the organic components 88 and chemistry due to loss of carbon and conversion of readily decomposable materials, such 89 as polysaccharides, celluloses and hemicelluloses, with only more recalcitrant compounds 90 such as lignin and humic substances remaining (Andriesse, 1988; Broder et al., 2012; Kuhry 91 and Vitt, 1996;...

Editorial handling by M. Kersten a b s t r a c tSurface soils from a 19 km 2 area in east London, UK were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) (n = 76).P 16 PAH ranged from 4 to 67 mg/kg (mean, 18 mg/ kg) and P 50 PAH ranged from 6 to 88 mg/kg (mean, 25 mg/kg).P 7 PCB ranged from 1 to 750 lg/kg (mean, 22 lg/kg) and P tri-hepta PCB ranged 9 to 2600 lg/kg (mean, 120 lg/kg). Compared to other international cities concentrations were similar for PAH but higher for PCB. Normal background concentrations (NBC) were calculated and compared to risk-based human health generic assessment criteria (GAC). Benzo[a]pyrene NBC for urban (6.9 mg/kg), semi-urban (4.4 mg/kg) and urban + semi urban (6 mg/kg) domains exceed residential (1 mg/kg) and allotment (2.2 mg/kg) LQM/CIEH GAC (at 6% SOM) and the Indeno[1,2,3-cd]pyrene NBC for urban (6.8 mg/kg) and urban + semi-urban (5.2 mg/kg) domains exceed the residential (4.2 mg/kg) LQM/CIEH GAC (at 6% SOM). Capsule Abstract: Normal background concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls are elevated in east London soils and in some cases exceed regulatory assessment criteria.

Fifty six sediment cores were collected along a 100 km longitudinal transect of the Thames estuary. Total Hg ranged from 0.01 to 12.07 mg/kg, with a mean of 2.10 mg/kg (n ¼ 351). Concentrations of the toxic metal decreased downstream from London to the outer estuary and were positively correlated to total organic carbon (TOC) content. Many Hg profiles showed a clear rise, peak and fall, reflecting changing anthropogenic input through time. Surface concentrations averaged 1.27 mg/kg, confirming the effectiveness of recent environmental legislation and improved river management. Sediments at >40 cm depth from London reaches of the river (Waterloo Bridge, Cuckolds Point (Rotherhithe), Butlers Wharf (Tower Bridge), Millwall, Deptford and Millennium Dome) were highly contaminated, with levels of Hg of >7 mg/kg. The outer Thames had lower Hg, with the exception of Rainham, Crossness and Cliffe. Benchmarking against UK guidelines for the disposal of dredged material revealed that 88 samples from 21 sites exceeded the 3 mg/kg criteria (unsuitable for disposal at sea); 173 fell between 0.3 and 3 mg/kg (further assessment required); and 90 were of no concern. Using Hg as a generic pollution marker, the tidal Thames is one of the world's most contaminated river-estuarine sediment systems.

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