. "Delta15 N as an indicator of N2-fixation by cyanobacterial mats in tropical marshes" . . "67" . . "Delta15 N as an indicator of N2-fixation by cyanobacterial mats in tropical marshes" . "Delta15N jako indicator fixace dus\u00EDku cyanobakteri\u00E1ln\u00EDmi sinicemi v tropick\u00FDch mok\u0159adech"@cs . "Cyanobacterial mats (CBM) in limestone-based tropical regions of the Caribbean contribute to the primary production, are crucial in marl formation and are known to fix di-nitrogen. Nitrogen fixation ranges from low (< 5 nmol C2H4 cm-2 h-1) to high (12 to 20 nmol C2H4 cm-2 h-1). A linear increase of nitrogenase activity with increasing amount of Stigonematales was proved. Nitrogen-fixing cyanobacteria have delta 15N usually close to 0 ppt. We measured N2-fixation at 12 \u2013 14 different locations parallel with measurement of relevant environmental characteristics and the natural abundance of delta 15N (-1.99 to 11.44 >). Path analysis of the dependence of delta 15N on N2-fixation, NO3-N, and NH4-N in water indicated that the effect of N2-fixation was more important than the effect of nitrogen amount/form in water. The evidence we present suggests that delta 15N can be used as an indicator of the level of N2-fixation by CBM."@en . . "Rejm\u00E1nek, M." . "559675" . "0168-2563" . "Biogeochemistry" . "Delta15 N as an indicator of N2-fixation by cyanobacterial mats in tropical marshes"@en . "16"^^ . . "delta 15N; cyanobacteria; nitrogen fixation; wetlands"@en . "Kom\u00E1rkov\u00E1, Jaroslava" . . . . "RIV/60077387:_____/04:00025994!RIV06-AV0-60077387" . "NL - Nizozemsko" . "Sinicov\u00E9 (cyanobakteri\u00E1ln\u00ED) n\u00E1rosty jsou d\u016Fle\u017Eitou sou\u010D\u00E1st\u00ED biocen\u00F3zy alkalick\u00FDch ba\u017Ein v Karibsk\u00E9 oblasti. Jsou prim\u00E1rn\u00EDmi producenty, fixuj\u00ED atmosf\u00E9rick\u00FD dus\u00EDk a vytv\u00E1\u0159ej\u00ED uhli\u010Ditanov\u00E9 sedimenty. Na 12-14 lokalit\u00E1ch v severn\u00EDm Belize jsme m\u011B\u0159ili fixaci N2, p\u0159\u00EDrodn\u00ED pod\u00EDl delta 15N (-1.99 to 11.44 >), chemismus vody a biomasy. Fixace N2 kol\u00EDsala od n\u00EDzk\u00FDch v\u00FDkonnost\u00ED (< 5 nmol) do vysok\u00FDch \u010D\u00EDsel (12 to 20 nmol C2H4 cm-2 h-1). Line\u00E1rn\u00ED vzr\u016Fst aktivity nitrogen\u00E1zy byl spojen se vzr\u016Fstaj\u00EDc\u00ED biomasou heterocyt\u00F3zn\u00EDch sinic (Stigonematales, Scytonema, Tolypothrix). Cyanobakt\u00E9rie, fixuj\u00EDc\u00ED dus\u00EDk maj\u00ED delta 15N oby\u010Dejn\u011B bl\u00EDzk\u00FD nule. Anal\u00FDza vztah\u016F mezi pod\u00EDlem delta 15N, fixac\u00ED N2 a koncentracemi NO3-N a NH4-N ve vod\u011B uk\u00E1zala, \u017Ee pod\u00EDl delta 15N v biomase je z\u00E1visl\u00FD nep\u0159\u00EDmo \u00FAm\u011Brn\u011B na fixaci N2, tak\u017Ee velmi jednoduch\u00E9 stanoven\u00ED pod\u00EDlu delta 15N m\u016F\u017Ee b\u00FDt indik\u00E1torem prob\u00EDhaj\u00EDc\u00ED fixace N2."@cs . "1"^^ . "Delta15N jako indicator fixace dus\u00EDku cyanobakteri\u00E1ln\u00EDmi sinicemi v tropick\u00FDch mok\u0159adech"@cs . "3"^^ . "Z(AV0Z6017912)" . . . . . "Delta15 N as an indicator of N2-fixation by cyanobacterial mats in tropical marshes"@en . "353;368" . . . "3" . . "RIV/60077387:_____/04:00025994" . "Cyanobacterial mats (CBM) in limestone-based tropical regions of the Caribbean contribute to the primary production, are crucial in marl formation and are known to fix di-nitrogen. Nitrogen fixation ranges from low (< 5 nmol C2H4 cm-2 h-1) to high (12 to 20 nmol C2H4 cm-2 h-1). A linear increase of nitrogenase activity with increasing amount of Stigonematales was proved. Nitrogen-fixing cyanobacteria have delta 15N usually close to 0 ppt. We measured N2-fixation at 12 \u2013 14 different locations parallel with measurement of relevant environmental characteristics and the natural abundance of delta 15N (-1.99 to 11.44 >). Path analysis of the dependence of delta 15N on N2-fixation, NO3-N, and NH4-N in water indicated that the effect of N2-fixation was more important than the effect of nitrogen amount/form in water. The evidence we present suggests that delta 15N can be used as an indicator of the level of N2-fixation by CBM." . "Rejm\u00E1nkov\u00E1, E." . "[7823A0D13631]" . .