Forest Inventory of a Northern Hardwood Forest: Bird Area at the Hubbard Brook Experimental Forest, 1981
TITLE
Forest Inventory of a Northern Hardwood Forest: Bird Area at the Hubbard Brook Experimental Forest, 1981
PRINCIPAL INVESTIGATOR(s)
Tom Sherry
Department of Ecology, Evolution, and Organismal Biology, Tulane University
New Orleans, LA 70118
USA
Dick Holmes
Biology Department, Dartmouth College
Hanover, NH 03755
USA
Thomas G. Siccama
Yale School of Forestry and Environmental Studies
OTHERS INVOLVED
Gene Likens
Institute of Ecosystem Studies
Millbrook, NY 12545
USA
Tim Fahey
Department of Natural Resources, Cornell University
Ithaca, NY 14853
USA
ABSTRACT:
The forest inventory surveys in the bird area were initiated in 1981 and transects were made permanent in 1991. The inventory is representative of approximately 2.5 km-squared of mid elevation northern hardwood forest. It consists of a total inventory of all trees >=10 cm dbh, within each of four 10 m wide belt transects. The parallel transects are placed approximately 200 m apart and run roughly in an east-west direction for 2200 to 2900 m. In 1991, each live stem >=10 cm dbh was tagged with a unique number. Tree vigor is assessed every two years and diameter is remeasured every ten years. Every two years, new tags are placed on stems that have grown into the 10 cm diameter class. A survey of smaller trees (>=2 to <10 cm dbh) was first taken in 1991 and is resurveyed every ten years. This dataset includes the initial inventory values measured in 1981
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
biomass, diameter breast height, forests, HBEF Bird Area, HBR, Hubbard Brook LTER, inventory, trees, vegetation, watersheds.
KEYWORD SET: LTER Core Research Areas
primary production.
BEGIN DATE
1981
END DATE
1981
LOCATION
The Bird Area studied here is a 2.5 km-squared area of mid elevation mature hardwood forest immediately below and to the west of the south-facing gauged watersheds at Hubbard Brook (elevation approximately 550 to 750 m).
West bounding coordinate: -71.764
East bounding coordinate: -71.725
North bounding coordinate: 43.9523
South bounding coordinate: 43.9389
Elevation
Minimum: 550
Maximum: 750
(Unit: meter)
SAMPLING BACKGROUND
The bird area has been used extensively for studies of bird populations since the 1970s. The area is forested by typical northern hardwood species (sugar maple, beech and yellow birch) over about 85% of its area, and by patches of red spruce and balsam fir over the remaining 15%. Four semi permanent transects through this area, each 2 to 3 km long, were flagged in 1981 and made permanent in 1991 with PVC stakes placed every 25 m. See the following webpage for more information:
http://www.hubbardbrook.org/watersheds/maps/bird_area_location_map.htm.
SAMPLING DESIGN
The inventory is representative of approximately 2.5 km2 of mid elevation northern hardwood forest. It consists of a total inventory of all trees >=10 cm dbh, within each of four 10 m wide belt transects. The parallel transects are placed approximately 200 m apart and run roughly in an east-west direction for 2200 to 2900 m. Each transect is divided into between 88 and 116 continuous, contiguous plots, each 25 m long and 10 m wide, for a total of 397 plots. The lengths of these plots are not always exactly 25 meters, due to drift or imprecise placement of the end stakes. The actual measured length of the plot is used to calculate the area of the plot.
In 1991, each live tree >=10 cm dbh was tagged with a unique number. This allowed us to track the fate of each tree and its progression from live to standing dead to snag to "down wood" at which point it was no longer followed. The 1981 data included here, however, do not include tagged trees.
DATA DESCRIPTION
The data consist of the diameters (dbh) of all the trees >10 cm dbh, live and dead, along each of four belt transects (6229 individual stems). An assessment of health or vigor was also recorded for each tree. Live trees were noted "sick" if they had very sparse foliage or yellowing foliage in the mid summer sampling. The presence and effect of beech bark disease was also noted. Diseased beech showed signs of beech bark disease (cankers) but did not otherwise show evidence of crown decline. Diseased beech with crown in decline had both cankers and were showing signs of physiological stress. Dead trees were recorded as standing dead trees (trees dead but retaining most of their fine branches) or as snags (trees broken off above dbh or with only their major large branches still intact). All stems that met the size criteria were measured individually, and in some years it was noted whether a stem was part of a group of stems from the same tree (i.e. multiple stems that split from a single trunk below breast height). For the Bird area, whether or not a stem was part of a group was not recorded until 1991.
NOTES
It is not possible to compare the data from 1981 with the following years on a plot by plot basis. This is because trees were not individually tagged until 1991 and trees on the lines between plots could have "drifted" between plots from 1981 to 1991 depending on the observers line of sight or decision as to whether the center of the base of a tree is in one plot or the adjoining plot or outside of the transect. For extensive notes about the details of these surveys and subsequent calculations, see the notes indicated at the bottom of the interactive calculation programs.
CALCULATIONS
Phytosociology or biomass summaries can be obtained by using our interactive calculators. Phytosociology summaries include basal area, density and frequency of each species for the area as a whole or for smaller units as chosen by the user. Diameter distributions for a specific species can also be selected. Biomass summaries include biomass estimates by plant part for each species for the area as a whole or for smaller units as chosen by the user. Options to estimate productivity and total nutrient pools in the vegetation are also available. For extensive details about how these calculations are made, see the notes indicated at the bottom of the calculator pages.
Related links
REFERENCES
  • Siccama, T.G., Fahey, T.J., Johnson, C.E.., Sherry, T., Denny, E.G., Girdler, E.B., Likens, G.E., and Schwarz, P. 2007. Population and biomass dynamics of trees in a northern hardwood forest at Hubbard Brook. Canadian Journal of Forest Research (37):737-749.
DATA ACCESS GUIDELINES
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: ba81veg.txt
Description: Inventory data for Bird Area 1981
ColumnVariableDescriptionUnitsCoded?Missing value label
1Plotplot numbernoneynone
2Lntransect line number (using line numbers 5,9,13,17 of an existing grid)noneynone
3Spspecies acronymnoneynone
4Sp#species numbernoneynone
5Seq#sequence number (unique number for each tree; multiple stems of same tree have same sequence)noneynone
6Tag#tag number (not relevant until 1991 when Bird Area trees were tagged)noney
-
7Dbhdiameter at breast height, in cmcentimeternnone
8Vigvigor codenoneynone
9Lngtplot length in meters (see Sampling Design)meternnone

CODES

Variable: Plot
Description:
An integer representing the plot
Variable: Ln
Code
Description
5
Line number 5 of an existing grid
9
Line number 9 of an existing grid
13
Line number 13 of an existing grid
17
Line number 17 of an existing grid
Variable: Sp, Sp#
Sp#
Sp code
Sp/Sp# description
1
ACSA
Sugar maple (Acer saccharum)
2
FAGR
American beech (Fagus grandifolia)
3
BEAL
Yellow birch (Betula alleghaniensis)
4
FRAM
White ash (Fraxinus americana)
5
ACSP
Mountain maple (Acer spicatum)
6
ACPE
Striped maple or moose wood (Acer pensylvanicum)
7
PRPE
Pin or fire cherry (Prunus pensylvanica)
8
PRVI
Choke cherry (Prunus virginiana)
9
ABBA
Balsam fir (Abies balsamea)
10
PIRU
Red spruce (Picea rubens)
11
BEPA
White or paper birch (Betula papyrifera)
12
SOAM
Mountain ash (Sorbus americana)
13
ACRU
Red maple (Acer rubrum)
14
TSCA
Eastern hemlock (Tsuga canadensis)
15
UNKN
unknown, used for unidentifiable rotten snags
16
POTR
Quaking aspen (Populus tremuloides)
17
PRSE
Black cherry (Prunus serotina)
18
AMSP
Shadbush (Amelanchier sp.)
19
POGR
Big-tooth aspen (Populus grandidentata)
20
SASP
Willow (Salix sp.)
21
COAL
Alternate-leaved dogwood (Cornus alternifolia)
22
PRSP
Cherry (unspecified) (Prunus sp.)
Variable: Sp#
Code
Description
1
Sugar maple (Acer saccharum)
2
American beech (Fagus grandifolia)
3
Yellow birch (Betula alleghaniensis)
4
White ash (Fraxinus americana)
5
Mountain maple (Acer spicatum)
6
Striped maple or moose wood (Acer pensylvanicum)
7
Pin or fire cherry (Prunus pensylvanica)
8
Choke cherry (Prunus virginiana)
9
Balsam fir (Abies balsamea)
10
Red spruce (Picea rubens)
11
White or paper birch (Betula papyrifera)
12
Mountain ash (Sorbus americana)
13
Red maple (Acer rubrum)
14
Eastern hemlock (Tsuga canadensis)
15
unknown, used for unidentifiable rotten snags
16
Quaking aspen (Populus tremuloides)
17
Black cherry (Prunus serotina)
18
Shadbush (Amelanchier sp.)
19
Big-tooth aspen (Populus grandidentata)
20
Willow (Salix sp.)
21
Alternate-leaved dogwood (Cornus alternifolia)
22
Cherry (unspecified) (Prunus sp.)
Variable: Seq#
Description:
A positive integer representing the sequence number for the current sample
Variable: Tag#
Description:
A positive integer tag identifier
Variable: Vig
Code
Description
0
healthy
1
diseased beech (with beech bark disease)
2
diseased beech with crown in decline
3
sick (trees with crown in decline)
4
standing dead tree
5
standing dead snag (no limbs left)

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
Tag#
-
(Tag not relevant until 1991 when Bird Area trees were tagged)