BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:CCRU Lunchtime Seminar: Linking sediment structure\, hydrological 
 functioning and biogeochemical cycling following de-embankment of restored
  coastal saltmarshes - Kate L Spencer [1]\, Simon J Carr [1]\, James A Tem
 pest [2]\, Lucy Diggens [1]\, Gemma L Harvey [1]\, Michelle A Morris [1]
DTSTART:20140605T113000Z
DTEND:20140605T123000Z
UID:TALK52916@talks.cam.ac.uk
CONTACT:Geography/SPRI Webmaster
DESCRIPTION:Tollesbury MR site\, Essex\n\nSaltmarsh restoration (managed r
 ealignment) undoubtedly provides environmental enhancement\, with vegetati
 on quickly re-establishing following the breach of sea walls and subsequen
 t tidal inundation of previously defended areas. However\, these environme
 nts have been ‘disturbed’ by previous land use and there is little und
 erstanding of the impacts of this disturbance on wider ecosystem functions
  and the quality and quantity of the biogeochemical ecosystem services pro
 vided by these restored environments.\n\nThis study examines physical sedi
 ment characteristics\, sediment structure (using X-ray microtomography)\, 
 sub-surface hydrology (using pressure transducers)\, and sediment and pore
 water geochemistry (major and trace elements\, major anions) in sediment c
 ores collected from undisturbed saltmarshes and those restored by de-emban
 kment.\n\nSub-surface sediments in restored saltmarshes have lower organic
  matter content\, lower moisture content and higher bulk density than undi
 sturbed sites. Using X-ray tomography a clear horizon can be observed whic
 h separates relict agricultural soils at depth with less dense and structu
 reless sediments deposited since de-embankment. Sub-surface hydrological r
 esponse to tidal flooding was subdued in the restored compared to the undi
 sturbed site\, suggesting that porewater flow may be impeded and/or flow p
 athways differ in restored saltmarsh sediments.\n\nThe undisturbed saltmar
 sh displayed typical vertical geochemical sediment profiles. However\, in 
 the restored sites total Fe and Mn are elevated at depth indicating an abs
 ence of diagenetic cycling\, whilst porewater sulphate and nitrate increas
 ed at depth suggesting that vertical solute transport is impeded in restor
 ed sites. In surface sediments\, though total Hg concentrations are simila
 r\, Hg methylation rates are significantly higher than in the undisturbed 
 saltmarsh suggesting that surface anoxia and poor drainage may result in i
 ncreased mobilization of Hg.\n\nThese findings have implications for the w
 ider biogeochemical ecosystem services offered by saltmarsh restoration an
 d highlight the need for integrated understanding of physical and biogeoch
 emical processes.\n\nSpeakers:\n\nKate L Spencer [1]\, Simon J Carr [1]\, 
 James A Tempest [2]\, Lucy Diggens [1]\, Gemma L Harvey [1]\, Michelle A M
 orris [1]\n\n1 School of Geography\, Queen Mary\, University of London\, M
 ile End Road\, London\, E1 4NS\, UK.\n2 Department of Geography\, Universi
 ty of Cambridge\n
LOCATION:Small Lecture Theatre\, Department of Geography\, Downing Site
END:VEVENT
END:VCALENDAR