Data Package Metadata View Summary

Hubbard Brook Nitrogen Oligotrophication (HBNO): Microbial Biomass, 2022-2023

General Information

Data Package:

Local Identifier:

knb-lter-hbr.419.1

Title:

Hubbard Brook Nitrogen Oligotrophication (HBNO): Microbial Biomass, 2022-2023

Alternate Identifier:

DOI PLACE HOLDER

Abstract:

The goal of this project is to test the overarching hypothesis that positive feedback mechanisms involving changes in seasonal cycles that diminish N availability to plants such that plant N demand is not met by soil N availability in northern forests. Specifically, we hypothesize that increasing N demand by plants (induced by increasing temperatures, longer growing seasons, and other environmental changes) leads to greater N resorption by trees in autumn, increased C:N in litter, and greater net immobilization of N by soil microbes in the following spring. However, the timing of snowmelt and soil freezing in spring may further affect net mineralization and N availability for plants. These hypotheses are being tested with a combination of observational, experimental, and modeling approaches at Hubbard Brook Experimental Forest in New Hampshire: 1) measurements at 14 previously established sites along an elevation/aspect climate gradient; 2) litter and snow manipulation experiments at six sites along the climate gradient to create variation in soil climate conditions and microbial N immobilization during spring. We leveraged 14 sites previously established along an elevation and aspect-driven climate gradient at Hubbard Brook as a “natural climate experiment to test our hypothesis that a positive feedback between N cycling during fall senescence and spring contributes to declining N availability in northern forests. This elevation gradient encompasses variation in mean annual air temperature of ~2.5 °C that is similar to the change projected to occur with climate change over the next 50–100 years in the northeastern U.S. There is relatively little variation in soils along the gradient. We are utilizing three sites at higher elevation (~550-660 m, north facing) and three sites at lower elevation (~375-500 m, south facing) for the litter and snow manipulation experiments to maximize the differences in temperature among the 14 sites.

Litterbox manipulation:

The objective of the litterfall manipulation experiment is to determine whether increases in autumn litter C:N ratios contribute to greater N immobilization by microbes and reductions in net mineralization and plant N uptake in spring, and ultimately, N oligotrophication in northern forest ecosystems. We applied early (low C:N litter that is lost from from hardwood foliage in the first two weeks of autumn) and late (high C:N litter that falls in the last two weeks of autumn) season litter in October 2022 that was collected in fall 2021 at rates equal to standing mass of litter (300 g m2). We also applied native litter that was collected from the forest floor of each intensive site to represent background levels of C:N in litter samples. This litter was applied to one litterbox at each of the six intensive sites. Following application of litter, we installed deer netting around and on top of each of the litterboxes to eliminate litter loss from wind. Soil samples were collected from these plots in November 2021, April 2022, May 2022, June 2022, November 2022, April 2023, May 2023, June 2023 and anlalysed for microbial biomass and activity, as described in the methods section.

Snow manipulation:

The objective of the snow manipulation experiment is to determine whether the timing of spring snowmelt, length of the spring, and soil freezing in spring affect microbial N immobilization, hydrologic losses, net mineralization, and plant N uptake. The snow manipulation treatment was conducted in the spring of 2022 and 2023. We manually halved (Removal treatment) or doubled (Addition treatment) snow water equivalent (SWE) in experimental plots in March of 2022 and 2023 to accelerate or delay by an average of one week, respectively, the onset of spring snowmelt. Soil Samples were collected from these plots in November 2021, April 2022, May 2022, June 2022, November 2022, April 2023, May 2023, June 2023 and anlalysed for microbial biomass and activity, as described in the methods section.

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.

Publication Date:

2024-12-05

For more information:
Visit:	DOI PLACE HOLDER

Time Period

Begin:

2021-11-09

End:

2023-06-12

People and Organizations
Contact:	Information Manager, Hubbard Brook LTER [ email ]
Creator:	Groffman, Peter M (Cary Insitute of Ecosystem Studies)
Creator:	Martel, Lisa D (Cary Institute of Ecosystem Studies)

Data Entities
Data Table Name:	Groffman_HBNO_microbial_biomass_2022-2023_for_EDI
Description:	Microbial Biomass data table

Detailed Metadata

Data Entities

Data Table


Data:	https://pasta-s.lternet.edu/package/data/eml/knb-lter-hbr/419/1/886bbeb7afc8e07c4c1040fc52afca50
Name:	Groffman_HBNO_microbial_biomass_2022-2023_for_EDI
Description:	Microbial Biomass data table
Number of Records:	704
Number of Columns:	14

Table Structure

Object Name:

Groffman_HBNO_microbial_biomass_2022-2023_for_EDI.csv

Size:

57026 byte

Authentication:

90bd469774b2a2f1bc07266fdebb3439 Calculated By MD5

Text Format:

Number of Header Lines:

Record Delimiter:

Orientation:

column

Simple Delimited:

Field Delimiter:	,
Quote Character:	"

Table Column Descriptions

Date

Plot

Elevation

Manip

Treat

Horizon

BIOC

RESP

NO3

NH4

BION

MIN

NIT

H2O

Column Name:

Date

Plot

Elevation

Manip

Treat

Horizon

BIOC

RESP

NO3

NH4

BION

MIN

NIT

H2O

Definition:

Sampling Date

Sampling Plot

Elevation

Field Manipulation

Field Treatment

Soil Horizon. Org=Oi/Oe/Oa, Min=mineral soil

Microbial Biomass Carbon (ug C/g dry soil)

Respiration (ug C/g dry soil/day)

Soil Nitrate

Soil Ammonium

Microbial Biomass N (ug N/g dry soil)

Potential Net N Mineralization (ug-N/g dry soil/day)

Potential Net Nitrification (μg N/g dry soil)

Gravimentric water content

External Measurement Definition, Link:

has unit Meter

has unit Micrograms per gram

has unit Milligram Per Kilogram

has unit Micrograms per gram

has unit Gram Per Gram

Storage Type:

dateTime

string

integer

string

float

Measurement Type:

dateTime

nominal

ratio

nominal

ratio

Measurement Values Domain:

Format	YYYY-MM-DD
Precision

Allowed Values and Definitions

Enumerated Domain

Code Definition

Code	E1
Definition	Extensive plot 1
Source

Code Definition

Code	E11b
Definition	Extensive plot 11b
Source

Code Definition

Code	E12
Definition	Extensive plot 12
Source

Code Definition

Code	E2
Definition	Extensive plot 2
Source

Code Definition

Code	E3
Definition	Extensive plot 3
Source

Code Definition

Code	E7
Definition	Extensive plot 7
Source

Code Definition

Code	E8
Definition	Extensive plot 8
Source

Code Definition

Code	E9
Definition	Extensive plot 9
Source

Code Definition

Code	IH1
Definition	Intensive High plot 1
Source

Code Definition

Code	IH2
Definition	Intensive High plot 2
Source

Code Definition

Code	IH3
Definition	Intensive High plot 3
Source

Code Definition

Code	IL1
Definition	Intensive Low plot 1
Source

Code Definition

Code	IL2
Definition	Intensive Low plot 2
Source

Code Definition

Code	IL3
Definition	Intensive Low plot 3
Source

Unit	meter
Type	integer

Allowed Values and Definitions

Enumerated Domain

Code Definition

Code	Litter
Definition	Litter manipulation plot
Source

Code Definition

Code	Snow
Definition	Snow manipulation plot
Source

Allowed Values and Definitions

Enumerated Domain

Code Definition

Code	Addition
Definition	Snow Addition plot
Source

Code Definition

Code	Control
Definition	Ambient Snow plot
Source

Code Definition

Code	Early
Definition	Early Harvest Litter
Source

Code Definition

Code	Late
Definition	Late Harvest Litter
Source

Code Definition

Code	Native
Definition	Native Site Litter
Source

Code Definition

Code	Removal
Definition	Snow Removal plot
Source

Allowed Values and Definitions

Enumerated Domain

Code Definition

Code	Min
Definition	Mineral soil horizons
Source

Code Definition

Code	Org
Definition	Oi/Oe/Oa soil horizons
Source

Unit	microgramPerGram
Type	real

Unit	microgramPerGramPerDay
Type	real

Unit	milligramPerKilogram
Type	real

Unit	milligramPerKilogram
Type	real

Unit	microgramPerGram
Type	real

Unit	microgramPerGramPerDay
Type	real

Unit	microgramPerGramPerDay
Type	real

Unit	gramPerGram
Type	real

Missing Value Code:

Code	NA
Expl	no data available

Code	NA
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Code	-9999.99
Expl	no data available

Accuracy Report:

Accuracy Assessment:

Coverage:

Methods:

Data Package Usage Rights

This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. Thank you.

Keywords

By Thesaurus:
HBES Vocabulary	HBR, Hubbard Brook Ecosystem Study, Hubbard Brook Experimental Forest, Hubbard Brook LTER, White Mountain National Forest
LTER Controlled Vocabulary	ecosystems, forests, soil, soil horizons, watersheds, climate change, ammonium, carbon, denitrification, frost, microbes, microbial biomass, microbial activity, microbial nitrogen, mineralization, nitrate, nitrification, nitrogen, respiration
LTER Core Research Area	disturbance patterns, inorganic nutrients

Methods and Protocols

These methods, instrumentation and/or protocols apply to all data in this dataset:

Methods and protocols used in the collection of this data package

Description:

Samples were obtained using a split-PVC corer. A split PVC corer consists of a piece of 2 inch (5 cm) PVC pipe, about 15-20 cm long, split lengthwise on both sides. One of these splits is duct-taped closed- the "hinge" side. Holding the corer firmly together, we hammer it 10-15cm into the ground. The corer is removed from the ground and then opened along the untaped split with the intact soil core inside. Two cores were taken at each plot.

LABORATORY PROCEDURES

Samples we shipped to the Cary Institute in Millbrook, NY for analysis. They were stored at 4o C between sampling and analysis (less than 1 week). Each core was split into two layers, organic (Oi/Oe/Oa) and mineral (generally the top 10 cm of mineral soil beginning with the A horizon) horizons. These were weighed and measured, and then composited with the duplicate core from the plot. Soils were manually homogenized: all large rocks, roots, and other non-decomposed organic material were removed, and samples were thoroughly mixed. No more than three minutes were spent homogenizing any sample. All samples were held at field moisture before analysis. Soil water content was determined gravimetrically.

Microbial biomass C and N content was measured using the chloroform fumigation-incubation method (Jenkinson and Powlson 1976). Soils were fumigated to kill and lyse microbial cells in the sample. The fumigated sample was inoculated with fresh soil and sealed in a jar, and microorganisms from the fresh soil grew vigorously using the killed cells as substrate. The flushes of carbon dioxide (CO2) and 2 M KCl extractable inorganic N (NH4+ and NO3-) released by the actively growing cells during a 10-day incubation at field moisture content were assumed to be directly proportional to the amount of C and N in the microbial biomass of the original sample. A proportionality constant (0.41) was used to calculate biomass C from the CO2 flush in the fumigated samples. Biomass N is the total inorganic N flush in the fumigated samples.

Inorganic N and CO2 production were also measured in "control" samples. Control samples were prepared in the same fashion as those listed above, but were not fumigated. These incubations provided estimates of microbial respiration and potential net N mineralization and nitrification. Microbial respiration was quantified from the amount of CO2 evolved over the 10-day incubation. Potential net N mineralization and nitrification were quantified from the accumulation of NH4+ plus NO3- and NO3- alone during the 10-day incubation. We measured 2 M KCl extractable inorganic N in the fresh soil samples to determine the initial soil NO3- and NH4+ concentrations. Carbon dioxide was measured by thermal conductivity gas chromatography. Inorganic N was measured colorometerically using an autoanalyzer.

CALCULATIONS

All results are expressed on a per gram of dry soil basis. Values can be converted to a “per area” basis using data on the mass of different soil horizons found elsewhere on the data page of this website.

REFERENCES

Jenkinson, D. S., and D. S. Powlson. 1976. "The effects of biocidal treatments on metabolism in soil – V: A method for measuring soil biomass. Soil Biology & Biochemistry 8:209-213.

People and Organizations

Publishers:

Organization:

Environmental Data Initiative

Email Address:

info@edirepository.org

Web Address:

https://edirepository.org

Id:

https://ror.org/0330j0z60

Creators:

Individual:

Peter M Groffman

Organization:

Cary Insitute of Ecosystem Studies

Address:

PO AB,

Millbrook, NY 12545

Email Address:

groffmanp@caryinstitute.org

Id:

https://orcid.org/0000-0001-8371-6255

Id:

https://ror.org/01dhcyx48

Individual:

Lisa D Martel

Organization:

Cary Institute of Ecosystem Studies

Email Address:

martell@caryinstitute.org

Id:

https://orcid.org/0000-0002-0156-4954

Id:

https://ror.org/01dhcyx48

Contacts:

Position:

Information Manager, Hubbard Brook LTER

Address:

234 Mirror Lake Road,

North Woodstock, NH 03262 USA

Phone:

(603) 726-8902 (voice)

Email Address:

hbr-im@lternet.edu

Web Address:

http://www.hubbardbrook.org

Temporal, Geographic and Taxonomic Coverage

Temporal, Geographic and/or Taxonomic information that applies to all data in this dataset:

Time Period

Begin:

2021-11-09

End:

2023-06-12

Sampling Site:

Description:

IL1: Intensive Low Elevation Plot 1

Site Coordinates:

Longitude (degree):

-71.71479424

Latitude (degree):

43.94617659

Sampling Site:

Description:

IL2: Intensive Low Elevation Plot 2

Site Coordinates:

Longitude (degree):

-71.72060047

Latitude (degree):

43.94807308

Sampling Site:

Description:

IL3: Intensive Low Elevation Plot 3

Site Coordinates:

Longitude (degree):

-71.73064174

Latitude (degree):

43.95019236

Sampling Site:

Description:

IH1: Intensive High Elevation Plot 1

Site Coordinates:

Longitude (degree):

-71.7684914

Latitude (degree):

43.93415543

Sampling Site:

Description:

IH2: Intensive High Elevation Plot 2.

Site Coordinates:

Longitude (degree):

-71.76717913

Latitude (degree):

43.93218854

Sampling Site:

Description:

IH3: Intensive High Elevation Plot 3

Site Coordinates:

Longitude (degree):

-71.76180633

Latitude (degree):

43.93077007

Sampling Site:

Description:

E1: Extensive Plot 1

Site Coordinates:

Longitude (degree):

-71.77291084

Latitude (degree):

43.92738579

Sampling Site:

Description:

E2: Extensive Plot 2

Site Coordinates:

Longitude (degree):

-71.77643367

Latitude (degree):

43.92305067

Sampling Site:

Description:

E3: Extensive Plot 3

Site Coordinates:

Longitude (degree):

-71.77745584

Latitude (degree):

43.91985666

Sampling Site:

Description:

E7: Extensive Plot 7

Site Coordinates:

Longitude (degree):

-71.71862125

Latitude (degree):

43.95490408

Sampling Site:

Description:

E8: Extensive Plot 8

Site Coordinates:

Longitude (degree):

-71.71984434

Latitude (degree):

43.95885229

Sampling Site:

Description:

E9: Extensive Plot 9

Site Coordinates:

Longitude (degree):

-71.72161276

Latitude (degree):

43.96068944

Sampling Site:

Description:

Extensive Plot 11-B

Site Coordinates:

Longitude (degree):

-71.74247222

Latitude (degree):

43.95552778

Sampling Site:

Description:

E12: Extensive Plot 12

Site Coordinates:

Longitude (degree):

-71.74066667

Latitude (degree):

43.95311111

Project

Parent Project Information:

Title:

Collaborative Research: Changing Seasonality and Nitrogen Reductions in the Northern Hardwood Forest

Personnel:

Individual:

Peter M Groffman

Organization:

Cary Insitute of Ecosystem Studies

Address:

PO AB,

Millbrook, NY 12545

Email Address:

groffmanp@caryinstitute.org

Id:

https://orcid.org/0000-0001-8371-6255

Id:

https://ror.org/01dhcyx48

Role:

Principal Investigator

Additional Award Information:

Funder:

National Science Foundation (NSF)

Funder ID:

https://ror.org/021nxhr62

Number:

2020443

Title:

Collaborative Research: Changing Seasonality and Nitrogen Reductions in the Northern Hardwood Forest

URL:

https://www.nsf.gov/awardsearch/showAward?AWD_ID=2020443

Other Metadata

Additional Metadata

additionalMetadata
        |___text '\n      '
        |___element 'metadata'
        |     |___text '\n         '
        |     |___element 'emlEditor'
        |     |        \___attribute 'app' = 'ezEML'
        |     |        \___attribute 'release' = '2024.10.30'
        |     |___text '\n      '
        |___text '\n   '

Copyright 2024 Environmental Data Initiative. This material is based upon work supported by the National Science Foundation under grants #2223103 and #2223104. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Please contact us with questions, comments, or for technical assistance regarding this web site or the Environmental Data Initiative. Please read our privacy policy to know what information we collect about you and to understand your privacy rights.

EDI is a collaboration between the University of New Mexico and the University of Wisconsin – Madison, Center for Limnology:

Data Package Metadata View Summary

Hubbard Brook Nitrogen Oligotrophication (HBNO): Microbial Biomass, 2022-2023

Data Entities

Data Table

Data Package Usage Rights

Keywords

Methods and Protocols

These methods, instrumentation and/or protocols apply to all data in this dataset:

People and Organizations

Temporal, Geographic and Taxonomic Coverage

Project

Parent Project Information:

Additional Metadata

Recently Added

Recently Updated

Data Package Metadata View Summary

Hubbard Brook Nitrogen Oligotrophication (HBNO): Microbial Biomass, 2022-2023

+/- Data Entities

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These methods, instrumentation and/or protocols apply to all data in this dataset:

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