Feng Z. Partitioning of atmospheric nitrogen under long-term reduced atmospheric deposition conditions in a Norway spruce forest ecosystem. - Göttingen: Universitätsverlag Göttingen, 2010. - xii, 98 p.: ill., graph. - (Göttinger Forstwissenschaften; Bd.4). - Ref.: p.87-96. - ISBN 978-3-941875-81-4; ISSN 1867-6731  Место хранения:   034 | Институт леса СО РАН | Красноярск | Библиотека

Оглавление / Contents

Tables ......................................................... IX Figures ........................................................ XI Abbreviations and Acronyms ................................... XIII 1 Introduction ................................................. 1 1.1 N input to terrestrial ecosystem ........................ 1 1.2 Impact of elevated N input on temperate forest ecosystems .............................................. 3 1.3 Distribution of N input among forest ecosystems ......... 4 1.4 SOM ..................................................... 5 1.4.1 SOM stability .................................... 5 1.4.2 SOM pools ........................................ 6 1.5 Application of N isotopes in forest ecosystem studies ... 7 1.5.1 Natural 15N abundance ............................ 7 1.5.2 15N tracer ....................................... 7 2 Objectives .................................................. 11 3 Materials and Methods ....................................... 13 3.1 Study site ............................................. 13 3.2 Experimental design .................................... 13 3.3 15N tracer experiment .................................. 17 3.3.1 Sampling and analysis ........................... 17 3.3.1.1 Tree compartments ...................... 17 3.3.1.2 Soil ................................... 18 3.3.1.3 Soil solution .......................... 18 3.3.2 Natural 15N abundance and N content in ecosystem compartments .......................... 20 3.3.3 N fluxes ........................................ 20 3.3.4 Calculation of 15N excess and recovery .......... 21 3.4 Density fractionation experiment ....................... 22 3.4.1 Density fractionation procedure ................. 22 3.4.2 Comparison of two aggregate-disrupting methods ......................................... 24 3.4.3 Preparation of density solution ................. 24 3.4.4 Analysis and calculation ........................ 24 3.5 Statistical analysis ................................... 25 4 Results ..................................................... 27 4.1 15N tracer experiment .................................. 27 4.1.1 The roof control plot ........................... 27 4.1.1.1 Natural 15N abundance .................. 27 4.1.1.2 N content in ecosystem compartments and N fluxes ........................... 28 4.1.1.3 bN enrichment in ecosystem compartments ........................... 29 4.1.1.4 15N recovery in ecosystem compartments ........................... 36 4.1.2 The clean rain plot ............................. 38 4.1.2.1 Natural 15N abundance .................. 38 4.1.2.2 N content in ecosystem compartments and N fluxes ........................... 38 4.1.2.3 15N enrichment in ecosystem compartments ........................... 40 4.1.2.4 l5N recovery ........................... 45 4.2 Density fractionation .................................. 48 4.2.1 Preparation of density solution ................. 48 4.2.2 Comparison of two aggregate-disrupting methods ......................................... 48 4.2.3 Distribution of ОС and N in soil density fractions ....................................... 49 4.2.3.1 Organic layer .......................... 49 4.2.3.2 Mineral soil layers .................... 49 4.2.4 Recovery of soil 15N ............................ 50 5 Discussion .................................................. 59 5.1 15N tracer experiment .................................. 59 5.1.1 Natural 15N abundance ........................... 59 5.1.2 15N recoveries .................................. 60 5.1.2.1 Under ambient atmospheric deposition (the roof control plot) ................ 60 5.1.2.1.1 SoH ......................... 60 5.1.2.1.2 Tree ........................ 61 5.1.2.1.3 Leaching .................... 62 5.1.2.2 Under long-term reduced atmospheric deposition (the clean rain plot) ....... 63 5.1.2.2.1 SoH ......................... 63 5.1.2.2.2 Tree ........................ 66 5.1.2.2.3 Leaching .................... 68 5.2 Density fractionation experiment ....................... 69 5.2.1 Preparation of density solution ................. 69 5.2.2 Comparison of two aggregate-disrupting methods ......................................... 69 5.2.3 Distribution of ОС and N in sod density fractions ....................................... 71 5.2.4 Recovery of soil 15N ............................ 73 6 Conclusion .................................................. 77 7 Summary ..................................................... 79 8 Zusammenfassung ............................................. 83 9 References .................................................. 87 10 Appendix .................................................... 97 Lebenslauf ..................................................... 99