TITLE
Leaf area index following the ice storm of January 1998
PRINCIPAL INVESTIGATOR(s)
Steven P.
Hamburg
Center for Environmental Studies, Brown University
Box 1943
Providence, RI 02912
USA
Center for Environmental Studies, Brown University
Box 1943
Providence, RI 02912
USA
Anne G.
Rhoads
Matthew
Vadeboncoeur
OTHERS INVOLVED
Tom
Siccama
Tim
Fahey
Geoff
Wilson
Brian
Weeks
BEGIN DATE
July 1998
END DATE
July 2006
LOCATION
Watershed 1
West bounding coordinate: -71.731339
East bounding coordinate: -71.726311
North bounding coordinate: 43.959286
South bounding coordinate: 43.952053
East bounding coordinate: -71.726311
North bounding coordinate: 43.959286
South bounding coordinate: 43.952053
Watershed 6
West bounding coordinate: -71.743462
East bounding coordinate: -71.735649
North bounding coordinate: 43.957001
South bounding coordinate: 43.949928
East bounding coordinate: -71.735649
North bounding coordinate: 43.957001
South bounding coordinate: 43.949928
LOCATION BACKGROUND
We began a long-term study of the recovery of the forest canopy following the ice storm of January 1998. Qualitative assessment of canopy damage began in May of 1998, and quantitative measures of damage based on leaf area index (LAI, leaf area per unit of ground area) began in July of 1998, and continued (not every year) through 2006. Both watersheds 1 and 6 (WS1, WS6) are subdivided into 25 X 25 m permanent plots.
Twenty-two damaged plots were selected for long-term monitoring of LAI from middle and upper elevational plots (elevations acc. to Whittaker et al. 1974) impacted by the ice storm on WS1 (10 plots) and WS6 (12 plots) using a stratified random design. All measured damaged plots were first stratified by weighted mean damage class (0- <1, 1-<2, and 2-<3), then by elevation. The long-term monitoring plots were then selected from these groupings in proportion to the damage class/elevational distribution. Five plots below 560 m on WS1 and five below 624 m on WS6 were also established to serve as undamaged references.
DATA COLLLECTION DESIGN
Twenty-two damaged plots were selected for long-term monitoring of LAI from middle and upper elevational plots (elevations acc. to Whittaker et al. 1974) impacted by the ice storm on WS1 (10 plots) and WS6 (12 plots) using a stratified random design. All measured damaged plots were first stratified by weighted mean damage class (0- <1, 1-<2, and 2-<3), then by elevation. The long-term monitoring plots were then selected from these groupings in proportion to the damage class/elevational distribution. Five plots below 560 m on WS1 and five below 624 m on WS6 were also established to serve as undamaged references.
In July of 1998 the LAI measurements were taken in the 32 plots using a leaf area meter . A 15 X 15 m subplot was delineated within the center of each pre-selected 25 X 25 m plot. Ten points were randomly chosen within each of these subplots. Two horizontal LAI readings (sensor held at 0°) were taken at each of these points, one measuring the LAI of the shrub plus tree canopy (1 m off the ground), and the other measuring that of only the tree canopy (2.5 m off the ground). The LAI-2000's optical sensor was attached to a telescoping pole to maintain consistent heights between points. The readings of the two outer rings were eliminated, decreasing the area viewed by the optical sensor (from 0° to 43° of zenith) and reducing the influence of trees outside of the plots. Readings were taken at dawn and dusk to meet the diffuse light requirement of the LAI-2000. Measurements were repeated in July 1999, 2000, 2001, 2005, on both watersheds, and in 2006 on W6 only.
DATA DESCRIPTION:
LAI readings were taken at two levels in the forest in order to measure the LAI of the understory and overstory canopies. Overstory or tree LAI readings were taken at 2.5 m from the ground and understory or shrub LAI readings were based on measurements taken at 1 m off the ground. To obtain shrub LAI values, the overstory LAI readings were subtracted from the readings taken at 1 m from the ground since these measurements also included the upper canopy. The ten readings taken in each plot were averaged to obtain a mean tree LAI and a mean shrub LAI value for that plot. The units for LAI are m2 of leaves/m2 of forest floor.
REFERENCES
- Rhoads, A.G., Hamburg, S.P., Fahey, T.J., Siccama, T.G., Hane, E.H., Battles, J., Cogbill, C., Randall, J., and Wilson, G. 2002. Effects of an intense ice storm on the structure of a northern hardwood forest. Canadian Journal of Forest Research 32:1763-1775.
- Rhoads, A.G., Hamburg, S.P., Fahey, T.J., Siccama, T.G., and Kobe, R. 2004. Comparing direct and indirect methods of assessing canopy structure in a northern hardwood forest. Canadian Journal of Forest Research 34:584-591.
- Welles, J.M. 1990. Some indirect methods of estimating canopy structure. Remote Sensing Rev. 5:31-43.
- Welles, J.M., and Norman, J.M. 1991. Instrument for indirect measurement of canopy architecture. Agron. J. 83:818-825.
- Whittaker, R.H., Bormann, F.H., Likens, G.E., and Siccama, T.G. 1974. The Hubbard Brook Ecosystem Study: Forest Biomass and Production. Ecol. Mon. 44:233-252.
DATA ACCESS GUIDELINES
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Digital data and its metadata derived from any research activity such as field observations, collections, laboratory analysis, experiments, or the post-processing of existing data and identified by a unique identifier issued by a recognized cataloging authority such as a site, university, agency, or other organization.
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party designated in the accompanying metadata of the Data Set as the primary contact for the Data Set.
The access to all LTER data is subject to requirements set forth by this policy document to enable data providers to track usage, evaluate its impact in the community, and confirm users' acceptance of the terms of acceptable use. These requirements are standardized across the LTER Network to provide contractual exchange of data between Site Data Providers, Network Data Providers, and Data Users that can be encoded into electronic form and exchanged between computers. This will allow direct access to data via a common portal once these requirements have been fulfilled. The following information may be required directly or by proxy prior to the transference of any data object:
Registration
Name
Affiliation
Email address
Full Contact Info
Acceptance of the General Public Use Agreement or Restricted Data Use Agreement, as applicable
A Statement of Intended Use that is compliant with the above agreements. Such statements may be made submitted explicitly or made implicitly via the data access portal interface.
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:
Acceptable Use. Use of the dataset will be restricted to academic, research, educational, government, recreational, or other not-for-profit professional purposes. The Data User is permitted to produce and distribute derived works from this dataset provided that they are released under the same license terms as those accompanying this Data Set. Any other uses for the Data Set or its derived products will require explicit permission from the dataset owner.
Redistribution. The data are provided for use by the Data User. The metadata and this license must accompany all copies made and be available to all users of this Data Set. The Data User will not redistribute the original Data Set beyond this collaboration sphere.
Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly cite 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.
Acknowledgement. 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 significantly to its content. Acknowledgements should identify the supporting party, the party that received the support, and any identifying information such as grant numbers.
Notification. The Data User will notify the Data Set Contact when any derivative work or publication based on or derived from the Data Set is distributed. The Data User will provide the data contact with two reprints of any publications resulting from use of the Data Set and will provide copies, or on-line access to, any derived digital products. Notification will include an explanation of how the Data Set was used to produce the derived work.
Collaboration. The Data Set has been released in the spirit of open scientific collaboration. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator.
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.
By viewing or downloading the data, I certify that I accept the conditions herein
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.
Digital data and its metadata derived from any research activity such as field observations, collections, laboratory analysis, experiments, or the post-processing of existing data and identified by a unique identifier issued by a recognized cataloging authority such as a site, university, agency, or other organization.
ndividual to whom access has been granted to this Data Set, including his or her immediate collaboration sphere, defined here as the institutions, partners, students and staff with whom the Data User collaborates, and with whom access must be granted, in order to fulfill the Data User's intended use of the Data Set
individual or institution that produced the Data Set
individual or institution that holds intellectual property rights to the dataset. Note that this may or may not be defined as a legal copyright. If no other party is designated in the metadata as Data Set Owner, it may be presumed that these rights are held by the Data Set Creator.
individual or institution providing access to the Data Sets.
party designated in the accompanying metadata of the Data Set as the primary contact for the Data Set.
NOTES ON DATA
The data is physically located at Brown University, Providence, RI
CONTACT PERSON
Steven
Hamburg
Center for Environmental Studies, Brown University
Box 1943
Providence, RI 02912
USA
Phone: (401)-863-1261
Fax: (401)-863-2700
Email: Steven_Hamburg@Brown.edu
Center for Environmental Studies, Brown University
Box 1943
Providence, RI 02912
USA
Phone: (401)-863-1261
Fax: (401)-863-2700
Email: Steven_Hamburg@Brown.edu
Data file:
lai.txt
Description: Leaf area index data at Hubbard Brook lter
CODES
Description: Leaf area index data at Hubbard Brook lter
| Column | Variable | Description | Units | Coded? | Missing value label |
| 1 | YEAR | Year data was collected | YYYY | n | none |
| 2 | WS | Watershed number | none | y | none |
| 3 | PLOT | Plot number | none | y | none |
| 4 | ELEVATION_BAND | Elevation band | none | y | none |
| 5 | ELEVATION_M | Elevation | meter | n | none |
| 6 | LAIT | Leaf area index (trees) | metersSquaredPerMetersSquared | n | -9.99 |
| 7 | LAIS | Leaf area index (trees and shrubs) | metersSquaredPerMetersSquared | n | -9.99 |
Variable: WS
|
Code
|
Description
|
|
1
|
Watershed 1
|
|
6
|
Watershed 6
|
|
Description:
|
> 0 integer id corresponding to an existent plot
|
|
Code
|
Description
|
|
low
|
within the low elevation band
|
|
mid
|
within the mid elevation band
|
|
high
|
within the high elevation band
|