Moose activity and nitrogen cycling along an elevation gradient on the snow removal plots at the Hubbard Brook Experimental Forest.
TITLE
Moose activity and nitrogen cycling along an elevation gradient on the snow removal plots at the Hubbard Brook Experimental Forest.
PRINCIPAL INVESTIGATOR(s)
Lynn Christenson
Vassar College
Biology Department
Poughkeepsie, NY 12604
USA

Phone: (845) 437-7418
Peter M. Groffman
Cary Institute of Ecosystem Studies
Box AB
Millbrook, NY 12545
USA

Phone: (845) 677-5343
ABSTRACT:
The response of moose activity and three tree species to soil freezing were measured through experimental manipulation (shoveling) of snow to induce soil freezing. In addition, mechanical clipping of plants to simulate moose browsing and the addition of 15N labeled moose feces were included to determine the biogeochemical and plant response. N dynamics were evaluated using soil tension lysimeters, soil sampling, tracing movement of moose fecal N into soil, plant and microbial pools and leaching loss. Both total N and 15N were measured in all pools and fluxes. Fluxes include N mineralization and nitrification rates. Rate of decomposition and fate was also followed for moose feces. This data set includes measurents from 2003 to 2006.
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
15N, balsam fir, HBEF Soil Freezing Study, HBR, Hubbard Brook LTER, isotopes, litter, moose, nitrogen, snow, soil freezing, sugar maple, viburnum.
KEYWORD SET: LTER Core Research Areas
disturbance.
BEGIN DATE
2003
END DATE
2006
LOCATION
Mt Kineo
West bounding coordinate: -71.778091
East bounding coordinate: -71.778091
North bounding coordinate: 43.918686
South bounding coordinate: 43.918686
SAMPLING DESCRIPTION
This research was conducted at the Hubbard Brook Experimental Forest. 48 experimental plots (2x2 m) were established on relatively level terrain on the north facing slope of Kineo Mt. (43.918686 N 71.778091 W) at the HBEF at an elevation of approximately 760 m. Each plot was selected to contain 3 naturally growing saplings of the same species (sugar maple, balsam fir or Viburnum) with 16 plots for each sapling species.
SAMPLE COLLECTION AND ANALYSIS
Lysimeter samples were collected monthly from January 2004 through December 2005. Tension was set at 0.276 MPa 24 h prior to collection of samples. Samples were analyzed for pH on the day of collection, and sub-samples for further chemical analyses were stored at 4 degrees C. A second sub-sample was frozen for later 15N analysis. NH4+ (salicylate method) and NO3- (cadmium reduction method) were analyzed on a Lachat Quikchem 8100 Flow Injection Analyzer. A persulfate digest method (modified from Cabrera and Beare 1993) was used to determine DON concentration.
All sapling plot soils were sampled in May and August of 2004 and 2005 (four sampling periods). On each sampling date, the surface litter was moved. A minimum of two cores were collected in each plot and composited. Soils were sampled to 10 cm depth, and the cores separated into organic, comprising the Oe and Oa horizons (forest floor), and mineral horizons. Soils were sieved and extracted to determine initial NO3 and NH4
Green and senescent leaf tissue was analyzed for total N, 15N, and C content. Light availability to the saplings was measured in August 2005 using canopy fisheye photography.
15N measurments were made only on the samples from plots containing the moose fecal pellets. Results are reported as Atom %, which is a ratio of 15N to 15N + 14N in the sample.
REFERENCES
  • Christenson, L.M. 2007. The biogeochemistry of moose and soil freezing: bigeochemical links between moose and trees. Dissertation, Syracuse University.
  • Christenson, L.M., Mitchell, M.J., Groffman, P.M., and Lovett, G.M. 2010. Winter climate change implications for decomposition in Northeastern forests: comparisons of sugar maple litter to herbivore fecal inputs. Global Change Biology 16(9):2589–2601.
  • Christenson, L.M., Mitchell, M.J., Groffman, P.M., and Lovett, G.M. 2014. Cascading effects of climate change on forest ecosystems: Biogeochemical links between trees and moose in the Northeast USA. Ecosystems 17(3):442-457.
DATA ACCESS GUIDELINES
Anyone is free to use these data for informational purposes but they cannot be used in any publication without permission of the author.



Data Use Policy



The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, government or other not-for-profit professional purposes.

2) Redistribution. The data and metadata are provided for use by the Data User. The Data User will not redistribute the original Data Set or metadata to others without the explicit permission of the Principal Investigator.

3) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly attribute the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier.

Citation example: Holmes, R.T. 2012. Bird Abundances at Hubbard Brook (1969-2010) and on three replicate plots (1986-2000) in the White Mountain National Forest. Durham, NH. Hubbard Brook Data Archive [Database]. http://hubbardbrook.org/data/dataset.php?id=81 (23 July 2012)

4) Acknowledgment: The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed to its content. Acknowledgments should identify the supporting party, the party that received the support, and any identifying information such as grant numbers.

Acknowledgment example: Data on [topic] were provided by [name of PI] on [date]. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station, Newtown Square, PA. Significant funding for collection of these data was provided by [agency]-[grant number], [agency]-[grant number], etc.

5) Consultation and questions. Data users are strongly encouraged to consult with the Principal Investigator(s) who collected these data for further information. Also, when appropriate, Data Users should consider including the Principal Investigator as a collaborator and/or co-author in the use of these data.

6) Notification. The Data User will notify the Principal Investigator of any publication or derivative work based on the Data Set. The Data User will also provide the Principal Investigator and/or the administrator of the Hubbard Brook Ecosystem Study with a pdf or two reprints of any publication(s) resulting from use of the Data Set.

7) Disclaimer. While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

8) Terms of Agreement. By accepting this Data Set, the Data User agrees to abide by the terms of this agreement. The Data Owner shall have the right to terminate this agreement immediately by written notice upon the Data User's breach of, or non-compliance with, any of its terms. The Data User may be held responsible for any misuse that is caused or encouraged by the Data User's failure to abide by the terms of this agreement.



CONTACT PERSON

Information Manager, Hubbard Brook LTER
234 Mirror Lake Road
North Woodstock, NH 03262
USA

Phone: (603) 726-8902
Email: hbr-im@lternet.edu

Data file: moose_soil.txt
Description: Soil measurements on Moose-freeze plot along an elevation gradient at the Hubbard Brook Experimental Forest
Notes on Data: The data are physically located in the Christenson Lab at Vassar College.
ColumnVariableDescriptionUnitsCoded?Missing value label
1MonthMonth of sample collectionnoneynone
2YearSample collection yearYYYYnnone
3SampleIndividual sample numbernoneynone
4HorizonSoil horizonnoneynone
5SpeciesTree speciesnoneynone
6Plotplot number replicatesnumbernnone
7LocationPlot location on Mount Kineononeynone
8TreatmentEight different treatments were usednoneynone
9ClipIndicates a plot that had foliage clipped to emulate moose browsingnoneynone
10PoopIndicates a plot where moose pellets were addednoneynone
11ShovelIndicates a plot that had snow cover removednoneynone
12MoistureMoisture content of the soilpercentn
-99.99
13pHpH of the organic horizon + top 10 cm of mineral soil, measured in waterdimensionlessn
-9.99
14MBCSoil microbial biomass carbon as ug C/gdw soilmilligramPerGramn
-999.99
15RespSoil microbial respiration, lab incubated samples, ug C/gdw soil/daymilligramPerGramPerDayn
-99.999
16IniNO3Initial soil nitrate (available), KCl extractable, ugN/gdw soilmicrogramPerGramn
-99.99
17IniNH4Intital soil ammonium (available), Kcl Extractable, as ugN/gdw soilmicrogramPerGramn
-999.99
18IniTINTotal soil inorganic nitrogen (NO3 + NH4) as ugN/gdw soilmicrogramPerGramn
-999.99
19IniAtom15N content of available TIN (NO3 + NH4) in soil extracts, expressed as percent of 15N + 14NatomPercentn
-9.9999
20ConTINIncubated (12 days) soil NO3 and NH4 as ugN/gdw soilmicrogramPerGramn
-999.99
21ConAtom15N content of incubated (12days) TIN (NO3 + NH4) in soil extracts, expressed as percent of 15N + 14NatomPercentn
-9.9999
22MicroNMicrobial biomass nitrogen determined by chloroform fumigation method, ugN/gdw soilmicrogramPerGramn
-999.99
23FumAtom15N content of soil extracts after chloroform fumigation and incubation, expressed as percent of 15N + 14NatomPercentn
-9.9999
24NMinSoil net mineralization rate as ugN per gram per daymicrogramPerGramPerDayn
-99.99
25NitrSoil net nitrification rate as ugNO3-N per gram per daymicrogramPerGramPerDayn
-99.99
26SoilNTotal soil nitrogen content as percentpercentn
-9.99
27SoilCTotal soil carbon content as percentpercentn
-99.99
28SoilCNSoil carbon to nitrogen ratiodimensionlessn
-99.99
29SoilAtom15N content of soil, expressed as percent of 15N + 14NatomPercentn
-9.9999

CODES

Variable: Month
Description:
Month of sample collection: May or August
Variable: Sample
Description:
A positive number representing an individual sample
Variable: Horizon
Code
Description
O
Organic soil horizon (Oe + Oa)
M
Mineral soil horizon to 10 cm
Variable: Species
SppNum
Species Code
Species/SppNum description
1
Maple
Sugar Maple
2
Viburnum
Viburnum sp.
3
Fir
Balsam Fir
Variable: Location
Code
Description
EK
East Kineo
WK
West Kineo
Variable: Treatment
Code
Description
1
clip shovel
2
clip shovel poop
3
control no treatment
4
poop shovel
5
clip poop
6
shovel
7
poop
8
clip
Variable: Clip
Code
Description
y
clipped
n
not clipped
Variable: Poop
Code
Description
y
poop
n
no poop
Variable: Shovel
Code
Description
y
shoveled
n
not shoveled

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
Moisture
-99.99
Data missing or not measured
pH
-9.99
Data missing or not measured
MBC
-999.99
Data missing or not measured
Resp
-99.999
Data missing or not measured
IniNO3
-99.99
Data missing or not measured
IniNH4
-999.99
Data missing or not measured
IniTIN
-999.99
Data missing or not measured
IniAtom
-9.9999
Data missing or not measured
ConTIN
-999.99
Data missing or not measured
ConAtom
-9.9999
Data missing or not measured
MicroN
-999.99
Data missing or not measured
FumAtom
-9.9999
Data missing or not measured
NMin
-99.99
Data missing or not measured
Nitr
-99.99
Data missing or not measured
SoilN
-9.99
Data missing or not measured
SoilC
-99.99
Data missing or not measured
SoilCN
-99.99
Data missing or not measured
SoilAtom
-9.9999
Data missing or not measured

Data file: moose_vegbiomass.txt
Description: Biomass and fecal pellet CN measurements on the moose-freeze plots along an elevation gradient at the Hubbard Brook Experimental Forest
Notes on Data: The data are physically located in the Christenson Lab at Vassar College.
ColumnVariableDescriptionUnitsCoded?Missing value label
1SpeciesTree speciesnoneynone
2Plotplot number replicatenumbernnone
3LocationPlot location on Mount Kineononeynone
4TreatmentEight different treatments were usednoneynone
5ClipIndicates a plot that had foliage clipped to emulate moose browsingnoneynone
6PoopIndicates a plot where moose pellets were addednoneynone
7ShovelIndicates a plot that had snow cover removednoneynone
8GreenFolNMean green foliage nitrogen content as percentpercentn
-9.99
9GreenFolCMean green foliage carbon content as percentpercentn
-99.99
10GreenFolCNMean green foliage carbon to nitrogen ratiodimensionlessn
-99.99
11GreenFolAtomMean 15N content of fresh foliage, expressed as percent of 15N + 14NatomPercentn
-9.9999
12LitterNMean litterfall nitrogen content as percentpercentn
-9.99
13LitterCMean litterfall carbon content as percentpercentn
-999.99
14LitterCNMean green foliage carbon to nitrogen ratiodimensionlessn
-99.99
15SapStemNMean sapling wood nitrogen content as percentpercentn
-9.99
16SapStemCMean sapling wood carbon content as percentpercentn
-999.99
17SapStemCNMean sapling wood carbon to nitrogen ratiodimensionlessn
-99.99
18SapStemAtomMean 15N content of sapling wood, expressed as percent of 15N + 14NatomPercentn
-9.9999
19SapRootNMean sapling root nitrogen content as percentpercentn
-9.99
20SapRootCMean sapling root carbon content as percentpercentn
-99.99
21SapRootCNMean sapling root carbon to nitrogen ratiodimensionlessn
-99.99
22SapRootAtomMean 15N content of sapling wood, expressed as percent of 15N + 14NatomPercentn
-9.9999
23LightPercent canopy ??closure?? as a measure of light availabilitypercentn
-99.99
24FecNMean moose fecal pellet final nitrogen content as percentpercentn
-9.99
25FecCMean moose fecal pellet final carbon content as percentpercentn
-99.99
26FecAtomMean 15N content of final moose fecal pellet, expressed as percent of 15N + 14NatomPercentn
-9.9999

CODES

Variable: Species
SppNum
Species Code
Species/SppNum description
1
Maple
Sugar Maple
2
Viburnum
Viburnum sp.
3
Fir
Balsam Fir
Variable: Location
Code
Description
EK
East Kineo
WK
West Kineo
Variable: Treatment
Code
Description
1
clip shovel
2
clip shovel poop
3
control no treatment
4
poop shovel
5
clip poop
6
shovel
7
poop
8
clip
Variable: Clip
Code
Description
y
clipped
n
not clipped
Variable: Poop
Code
Description
y
poop
n
no poop
Variable: Shovel
Code
Description
y
shoveled
n
not shoveled

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
GreenFolN
-9.99
Data missing or not measured
GreenFolC
-99.99
Data missing or not measured
GreenFolCN
-99.99
Data missing or not measured
GreenFolAtom
-9.9999
Data missing or not measured
LitterN
-9.99
Data missing or not measured
LitterC
-999.99
Data missing or not measured
LitterCN
-99.99
Data missing or not measured
SapStemN
-9.99
Data missing or not measured
SapStemC
-999.99
Data missing or not measured
SapStemCN
-99.99
Data missing or not measured
SapStemAtom
-9.9999
Data missing or not measured
SapRootN
-9.99
Data missing or not measured
SapRootC
-99.99
Data missing or not measured
SapRootCN
-99.99
Data missing or not measured
SapRootAtom
-9.9999
Data missing or not measured
Light
-99.99
Data missing or not measured
FecN
-9.99
Data missing or not measured
FecC
-99.99
Data missing or not measured
FecAtom
-9.9999
Data missing or not measured

Data file: moose_lys_means.txt
Description: Seasonal mean lysimeter chemistry from tension lysimeters measured on Moose-freeze plots along an elevation gradient on Mount Kineo at the Hubbard Brook Experimental Forest. Lysimeters were installed below the major rooting zone (20– 40 cm depth).
Notes on Data: The data are physically located in the Christenson Lab at Vassar College.
ColumnVariableDescriptionUnitsCoded?Missing value label
1SpeciesTree speciesnoneynone
2Plotplot number replicatesnumbernnone
3LocationPlot location on Mount Kineononeynone
4TreatmentEight different treatments were usednoneynone
5ClipIndicates a plot that had foliage clipped to emulate moose browsingnoneynone
6PoopIndicates a plot where moose pellets were addednoneynone
7ShovelIndicates a plot that had snow cover removednoneynone
8LysNH4GrowMean ammonium concentration of soil solution during the growing seasonmilligramPerLitern
-9.999
9LysNO3GrowMean nitrate concentration of soil solution during the growing seasonmilligramPerLitern
-9.999
10LysTINGrowMean total inorganic nitrogen (NH4+NO3) concentration of soil solution during the growing seasonmilligramPerLitern
-9.999
11LysTINAtomGrow15N content of TIN (NO3 + NH4) in soil solution during the growing season, expressed as percent of 15N + 14NatomPercentn
-9.9999
12LysNH4NonGrowMean ammonium concentration of soil solution during the dormant seasonmilligramPerLitern
-9.999
13LysNO3NonGrowMean nitrate concentration of soil solution during the dormant seasonmilligramPerLitern
-9.999
14LysTINNonGrowMean total inorganic nitrogen (NH4+NO3) concentration of soil solution during the dormant seasonmilligramPerLitern
-9.999
15LysTINAtomNonGrow15N content of TIN (NO3 + NH4) in soil solution during the dormant season, expressed as percent of 15N + 14NatomPercentn
-9.9999

CODES

Variable: Species
SppNum
Species Code
Species/SppNum description
1
Maple
Sugar Maple
2
Viburnum
Viburnum sp.
3
Fir
Balsam Fir
Variable: Location
Code
Description
EK
East Kineo
WK
West Kineo
Variable: Treatment
Code
Description
1
clip shovel
2
clip shovel poop
3
control no treatment
4
poop shovel
5
clip poop
6
shovel
7
poop
8
clip
Variable: Clip
Code
Description
y
clipped
n
not clipped
Variable: Poop
Code
Description
y
poop
n
no poop
Variable: Shovel
Code
Description
y
shoveled
n
not shoveled

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
LysNH4Grow
-9.999
Data missing or not measured
LysNO3Grow
-9.999
Data missing or not measured
LysTINGrow
-9.999
Data missing or not measured
LysTINAtomGrow
-9.9999
Data missing or not measured
LysNH4NonGrow
-9.999
Data missing or not measured
LysNO3NonGrow
-9.999
Data missing or not measured
LysTINNonGrow
-9.999
Data missing or not measured
LysTINAtomNonGrow
-9.9999
Data missing or not measured