uid=BNZ,o=lter,dc=ecoinformatics,dc=org all public read knb-lter-bnz.22.10 F.S. Stuart Chapin PI, Professor of Ecology

Department of Biology and Wildlife; Institute of Arctic Biology: University of Alaska Fairbanks 193 Arctic Health P.O. Box 757000 Fairbanks AK 99775 United States

(907) 474-7922 (907) 474-6967 terry.chapin@alaska.edu http://terrychapin.org/ 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 Leslie A. Viereck Associated investigator 1998-01-15 This data file includes the net nitrogen mineralization potentials and net nitrification potentials estimated in a lab incubation for the top 20cm of soils collected as part of the harvest of the artificial communities experiment in 2002. The 2002 harvest was conducted to calculate total plant and soil N and C accumulation and above ground biomass in the artificial communities after 13 years of growth. Aboveground biomass data can be found in the data file 'Artificial communities biomass in 2002'. And soil physical characteristics including bulk densities can be found in the file 'Artificial communities soil physical characteristics'. artificial communities Seedling height survival alder spruce Succession

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http://www.lter.uaf.edu/data_detail.cfm?datafile_pkey=22 Site information unavailable -148.2701852 -148.1435205 64.73028888 64.68584608 1992-07-01 2002-08-03

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

Three types of 20 m x 20 m artificial communities were established on each of six replicate early successional sites (two replicates at each of three LTER sites): pure spruce plots planted at 1 m spacing, plots with spruce mixed with alder (spruce planted at 1 m spacing, alder planted between spruce seedlings), and pure spruce in which N fertilizer will be added (N was never added). As a result of bank erosion, several of the plots at FP1A were destroyed, and that site was eliminated. Pure spuirce plots (also referred to as communities) were assigned the designator "PS" (PS1, PS2, PS3, and PS4). Mixed alder and spruce plots (also referred to as communities) were assigned the designator "AS" (AS2 and AS2).

Methods: Four points were randomly selected within each plot for quadrate sampling in the 2002 harvest. We took soil cores to a depth of 1m from the center of each quadrate. We divided the entire soil core into 3 segments based on depth: 0-5cm, 5-20cm, and 20-100cm. each segment was separated into mineral soil, organic soil, mixed (mineral and organic soil that could not be separated into a specific component), and buried organic soil. Buried organic soils were organic soils found beneath mineral soil because of silt deposition. All buried organic layers were compositied into a single sample in each segment. We recorded the wet weight (field moisture content) of each sample and calculated the dry weight using the wet to dry ratio. The wet to dry ratio was determined in the lab after weighing, oven drying, and re-weighing a sub-sample of each soil. Potential net mineralization rates were determined on the separated soil components from the top 20 cm of the core. On 3 August, 2002, two 10 g samples (fresh weight) of each soil were placed into separate 150ml specimen cups. No adjustments for water holding capacity was made. Nitrogen was immediately extracted form one sample of each pair. The remaining sample was placed into a 1 L mason jar, covered with a polyethylene bag (to maintain moisture content but allow for gas exchange), and placed on a lab shelf to incubate at room temperature. Nitrogen was extracted from these remaining samples following 38 days of incubation. Nitrogen was extracted with 1 M KCl. 75 ml of KCl was placed into each specimen cup. These were capped and shaken for one hour on a shaker table at approximately 250 rpm. After shaking, the samples were extracted under a vacuum through a glass fiber filter. Solution NH4+-N and NO2/NO3-N of each extract was determined colorimetrically on a modified technicon autoanalyzer (Tarrytown, New York, USA). Potential net nitrogen mineralization rates (µg N/g dwt soil/day) were calculated as the final extractable ammonium and nitrate concentrations minus the initial ammonium and nitrate concentrations. Potential net nitrification rates (µg N/g dwt soil/day) were calculated as the final extractable nitrate concentrations minus the initial nitrate concentrations.

geoReference 1992-07-01 2002-08-03

Once

22_Artificial_communities_net_N_mineralization_and_nitrification_potentials.txt Overview: This data file includes the net nitrogen mineralization potentials and net nitrification potentials estimated in a lab incubation for the top 20cm of soils collected as part of the harvest of the artificial communities experiment in 2002. The 2002 harvest was conducted to calculate total plant and soil N and C accumulation and above ground biomass in the artificial communities after 13 years of growth. Aboveground biomass data can be found in the data file “Artificial communities biomass in 2002”. And soil physical characteristics including bulk densities can be found in the file “Artificial communities soil physical characteristics”. Methods: Four points were randomly selected within each plot for quadrate sampling in the 2002 harvest. We took soil cores to a depth of 1m from the center of each quadrate. We divided the entire soil core into 3 segments based on depth: 0-5cm, 5-20cm, and 20-100cm. each segment was separated into mineral soil, organic soil, mixed (mineral and organic soil that could not be separated into a specific component), and buried organic soil. Buried organic soils were organic soils found beneath mineral soil because of silt deposition. All buried organic layers were compositied into a single sample in each segment. We recorded the wet weight (field moisture content) of each sample and calculated the dry weight using the wet to dry ratio. The wet to dry ratio was determined in the lab after weighing, oven drying, and re-weighing a sub-sample of each soil. Potential net mineralization rates were determined on the separated soil components from the top 20 cm of the core. On 3 August, 2002, two 10 g samples (fresh weight) of each soil were placed into separate 150ml specimen cups. No adjustments for water holding capacity was made. Nitrogen was immediately extracted form one sample of each pair. The remaining sample was placed into a 1 L mason jar, covered with a polyethylene bag (to maintain moisture content but allow for gas exchange), and placed on a lab shelf to incubate at room temperature. Nitrogen was extracted from these remaining samples following 38 days of incubation. Nitrogen was extracted with 1 M KCl. 75 ml of KCl was placed into each specimen cup. These were capped and shaken for one hour on a shaker table at approximately 250 rpm. After shaking, the samples were extracted under a vacuum through a glass fiber filter. Solution NH4+-N and NO2/NO3-N of each extract was determined colorimetrically on a modified technicon autoanalyzer (Tarrytown, New York, USA). Potential net nitrogen mineralization rates (µg N/g dwt soil/day) were calculated as the final extractable ammonium and nitrate concentrations minus the initial ammonium and nitrate concentrations. Potential net nitrification rates (µg N/g dwt soil/day) were calculated as the final extractable nitrate concentrations minus the initial nitrate concentrations. Description of column headings: Sample,Site, Community,Rep (the community replicate),Quadrate( the quadrate replictae),Soil type (organic, mineral, buried organic, or mixed organix and mineral),Soil sub-type(identifies if the organic layer was buried),Depth,NO2/NO3-N ppm (7 Aug 02),NH4-N ppm (7 Aug 02),NO2/NO3-N ppm (10 Sept 02),NH4-N ppm (10 Sept 02),Extract volume (mls),ug NO2/NO3-N (7 Aug 02),ug NH4-N (7 Aug 02),ug NO2/NO3-N (10 Sept 02),ug NH4-N (10 Sept 02),Mass wet soil (g),Soil wet to dry ratio,Mass dry soil (g),Incubation durration (days),Net N mineralization potential (ug N/g dwt soil/day),Net nitrification potential (ug N/g dwt soil/day) 22_Artificial_communities_net_N_mineralization_and_nitrification_potentials.txt 1 \n \n column \t http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-bnz..&urlTail=/ascii/files/22_Artificial_communities_net_N_mineralization_and_nitrification_potentials.txt Sample Sample Sample number integer Sample number Site Site Sites name for earch record. string Sites name for earch record. Community Community A way to distinguish between Spruce and mixed Spruce sites. string PS Pure Spruce AS Mixed Spruce Rep Rep Replication number integer Replication number Quadrate Quadrate Each Rep was broken into four quadrates. integer Each Rep was broken into four quadrates. Soil type Soil type A definition of which Soil type is beening measured (organic, mineral, buried organic, or mixed organix and mineral string A definition of which Soil type is beening measured (organic, mineral, buried organic, or mixed organix and mineral Soil sub-type Soil sub-type Identifies if the organic layer was buried string Identifies if the organic layer was buried Depth Depth Depth of core string centimeter real NO2/NO3-N ppm (7 Aug 02) NO2/NO3-N ppm (7 Aug 02) Parts per million NO2/NO3-N float ppm real NH4-N ppm (7 Aug 02) NH4-N ppm (7 Aug 02) Parts per million NH4-N float ppm real NO2/NO3-N ppm (10 Sept 02) NO2/NO3-N ppm (10 Sept 02) Parts per million NO2/NO3-N float ppm real NH4-N ppm (10 Sept 02) NH4-N ppm (10 Sept 02) Parts per million NH4-N float ppm real Extract volume (mls) Extract volume (mls) Extract volume float mls real ug NO2/NO3-N (7 Aug 02) ug NO2/NO3-N (7 Aug 02) Micrograms of NO2/NO3-N float ug real ug NH4-N (7 Aug 02) ug NH4-N (7 Aug 02) Micrograms of NH4-N float ug real ug NO2/NO3-N (10 Sept 02) ug NO2/NO3-N (10 Sept 02) Micrograms of NO2/NO3-N float ug real ug NH4-N (10 Sept 02) ug NH4-N (10 Sept 02) Micrograms of NH4-N float ug real Mass wet soil (g) Mass wet soil (g) Mass wet soil float Mass wet soil Soil wet to dry ratio Soil wet to dry ratio Soil wet to dry ratio float dimensionless real Mass dry soil (g) Mass dry soil (g) Mass dry soil float Mass dry soil Incubation durration (days) Incubation durration (days) Incubation durration in number of days integer Incubation durration in number of days Net N mineralization potential (ug N/g dwt soil/day) Net N mineralization potential (ug N/g dwt soil/day) Net N mineralization potential float ug real Net nitrification potential (ug N/g dwt soil/day) Net nitrification potential (ug N/g dwt soil/day) Net nitrification potential float ug real