uid=BNZ,o=lter,dc=ecoinformatics,dc=org all public read knb-lter-bnz.51.10 Knut Kielland

Institute of Arctic Biology University of Alaska Fairbanks P.O. Box 757000 Fairbanks AK 99775 United States

(907) 474-7164 (907) 474-6967 kkielland@alaska.edu http://www.iab.uaf.edu/~knut_kielland/ Bonanza Creek LTER Data Manager

Boreal Ecology Cooperative Research Unit University of Alaska Fairbanks P.O. Box 756780 Fairbanks AK 99775 USA

907-474-6364 907-474-6251 jpdowning@alaska.edu http://www.lter.uaf.edu Karl Olson

Institute of Arctic Biology University of Alaska Fairbanks P.O. Box 757000 Fairbanks AK 99775 United States

(907) 474-5540 Associated investigator 2002-10-15 Because soil microoorganisms preferencially discriminate either for or against heavy nitrogen isotopes in organic compounds we can learn something about the route these compounds take through any given system by looking at the isotopic ratio of heavy to light nitrogen within a pool as compared to the ratio for the system as a whole. An enriched pool means that 15N has been discriminated for, while a depleted pool means 15N has been discriminated against. By determining the del 15N values for soil protein, amino acids, ammonium, the soil microbial population, and plant roots and xylem we can learn something about where plants are deriving there nitrogen nutrition. isotope xylem nitrogen soil amino acids ammonium roots floodplain Biogeochemistry

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http://www.lter.uaf.edu/data_detail.cfm?datafile_pkey=51 Site information unavailable -148.3790685 -148.1435205 64.7666796 64.66966 2002-10-24 2002-10-24

Completed

Bonanza Creek LTER Data Manager

Boreal Ecology Cooperative Research Unit University of Alaska Fairbanks P.O. Box 756780 Fairbanks AK 99775 USA

907-474-6364 907-474-6251 jpdowning@alaska.edu http://www.lter.uaf.edu Bonanza Creek LTER

Boreal Ecology Cooperative Research Unit University of Alaska Fairbanks P.O. Box 756780 Fairbanks AK 99775 USA

907-474-6364 907-474-6251 Bonanza Creek LTER

We are collecting soil and plant pools of nitrogen and analyzing them for their del 15N values.

We pulled xylem sap from freshly cut banches by stripping the outer cambium from the branch and subjecting the remaining xylem to a vacccuum. Known volumes of the sap were dried onto chromosorb and analyzed for del 15N on a mass spec. Soils were extracted in sodium bicarbonate and the proteins condensed with trichloro acetic acid. The samples were spun in a centrifuge and the resulting pellet dried on chromosorb. Likewise, these samples were analyzed for del 15N on a mass spec.

154_1432_del15N.txt ASCII .txt file format Finnigan Delta+ IRMS Results Investigator: KIELLAND Analyst: Howe Run: kielland02Oct24-1 Date: 24-Oct-02 Matrix: xylem & soil extract on chromosorb 10 ml soil extracts in .1 M NaHCO3 complexed with 1 g TCA and condensed. Units: N Amp. (V), Mass N (mg), d15N At-Air (0/00) Willow soil cores taken from LTER site 1C (213), Alder cores from site 1A (211), 5A and 5C refer to soil cores taken from the LTER sites of the same names (251 and 253 respectively). 154_1432_del15N.txt 11 \n \n column \t http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-bnz..&urlTail=/ascii/files/154_1432_del15N.txt Sample Name Sample Name Willow soil cores taken from LTER site 1C (213), Alder cores from site 1A (211), 5A and 5C refer to soil cores taken from the LTER sites of the same names (251 and 253 respectively). string Willow soil cores taken from LTER site 1C (213), Alder cores from site 1A (211), 5A and 5C refer to soil cores taken from the LTER sites of the same names (251 and 253 respectively). N Amp. N Amp. Nitrogen Amplification float Nitrogen Amplification Mass N Mass N Mass Nitrogen float milligram real d15N d15N D15N Values float dimensionless real