. "2006-01-01+01:00"^^ . . . "Peatlands accumulate one third of the world's soil carbon. During climatic warming, higher emanations of greenhouse gases, accompanying thinning of peat deposits, may lead to further temperature increases. We will explore the relationship between C cycling in peatlands and climate by a combination of downcore reconstructions and laboratory manipulations of peat cores collected in the Czech Republic and northern Sweden. The formation of CO2 and CH4 during peat decomposition depends not only on temperature, but also on organic matter quality. Preliminary data indicate that bulk C can become both isotopically lighter and heavier downcore, but it is not known which C species are responsible for these isotope shifts. Therefore we will examine vertical changes in peat organic matter speciation. A sequential extraction will be used to quantify 9 organic fractions, and isotope composition of the most abundant C forms will be determined. We will further perform laboratory manipulations of"@en . . "organic soils; carbon; isotopes; climate"@en . . "2009-10-22+02:00"^^ . "Carbon isotope speciation in peat bogs in relation to climate change"@en . . . "0"^^ . . "2008-12-31+01:00"^^ . "1"^^ . "A comparative biogeochemical study was performed in a mid-latitude and a boreal wetland to predict the response of organic soils to global warming. Two approaches were taken. First, we compared carbon speciation and carbon isotope speciation in vertical"@en . . . . . "organic soils" . "0"^^ . "Izotopov\u00E9 slo\u017Een\u00ED forem uhl\u00EDku v ra\u0161elini\u0161t\u00EDch ve vztahu ke klimatick\u00FDm zm\u011Bn\u00E1m" . . . "Ra\u0161elini\u0161t\u011B p\u0159edstavuj\u00ED celou jednu t\u0159etinu sv\u011Btov\u00E9ho p\u016Fdn\u00EDho rezervo\u00E1ru uhl\u00EDku. B\u011Bhem oteplov\u00E1n\u00ED klimatu m\u016F\u017Ee doch\u00E1zet k vy\u0161\u0161\u00EDm emis\u00EDm sklen\u00EDkov\u00FDch plyn\u016F z ra\u0161elini\u0161\u0165. Ra\u0161elini\u0161t\u011B se z\u00E1rove\u0148 budou zten\u010Dovat. Vy\u0161\u0161\u00ED emise sklen\u00EDkov\u00FDch plyn\u016F mohou v\u00E9st k dal\u0161\u00EDmu n\u00E1r\u016Fstu teploty a urychlov\u00E1n\u00ED klimatick\u00FDch zm\u011Bn. Vztah mezi cyklem C v ra\u0161elini\u0161t\u00EDch a klimatem budeme zkoumat na vertik\u00E1ln\u00EDch profilech ra\u0161elini\u0161ti a za u\u017Eit\u00ED laboratorn\u00EDch manipulac\u00ED ra\u0161elinn\u00FDch monolit\u016F z \u010Cesk\u00E9 republiky a severn\u00EDho \u0160v\u00E9dska. P\u0159edb\u011B\u017En\u00E1 data nazna\u010Duj\u00ED, \u017Ee celkov\u00FD organick\u00FD C m\u016F\u017Ee b\u00FDt s p\u0159ib\u00FDvaj\u00EDc\u00ED hloubkou obohacov\u00E1n t\u011B\u017E\u0161\u00EDm izotopem 13C nebo leh\u010D\u00EDm izotopem 12C. Nen\u00ED v\u0161ak zn\u00E1mo, kter\u00E9 typy slou\u010Denin zp\u016Fsobuj\u00ED tyto kontrastn\u00ED izotopov\u00E9 gradienty. Proto budeme studovat vertik\u00E1ln\u00ED zm\u011Bny v obsaz\u00EDch r\u016Fzn\u00FDch forem organick\u00FDch l\u00E1tek v ra\u0161elin\u011B. U\u017Eijeme sekven\u010Dn\u00ED extrakce ke kvantifikaci 9 forem C. U nejv\u00EDce zastoupen\u00FDch forem C ur\u010D\u00EDme jejich izotopov\u00E9 slo\u017Een\u00ED. P\u0159i laboratorn\u00EDch manipulac\u00EDch teploty a vlhkosti ra\u0161elinn\u00FDch" . " isotopes" . "http://www.isvav.cz/projectDetail.do?rowId=GA205/06/1582"^^ . . . " carbon" . "Byla provedena srovn\u00E1vac\u00ED studie biogeochemick\u00E9 odezvy ra\u0161elini\u0161\u0165 na glob\u00E1ln\u00ED oteplov\u00E1n\u00ED. Na dvou lokalit\u00E1ch, li\u0161\u00EDc\u00EDch se zem\u011Bpisnou \u0161\u00ED\u0159kou a pr\u016Fm\u011Brnou ro\u010Dn\u00ED teplotou, byly stanoveny zm\u011Bny obsah\u016F jednotliv\u00FDch forem uhl\u00EDku a jejich izotopov\u00E9ho slo\u017Een\u00ED s r"@cs . "6"^^ . "6"^^ . "2008-04-25+02:00"^^ . . "GA205/06/1582" . . . .