A DATA SET is a series of observations collected by the same methodology. Each data set should have documentation sufficient for someone unfamiliar with the research to replicate the study. Data sets may be broken into subsets (data files) that are discrete in space and time, in that order. The documentation for a data set should include all spatial and temporal subdivisions of the data.

(Data, Abstract, Methods, Variables)

NOTES:

• Add rows to tables or lines to paragraphs as you need them for entering your data.
• Contact emelendez@lternet.edu, if you have any question.

PERSON(S) COMPLETING THIS FORM: E-MAIL ADDRESS: 

DATA SET IDENTIFIER: Regeneration after Hurricane Hugo of woody species greater than 1m tall (9ha grid, El Verde)(Wood fall from Hurricane Hugo 9Ha Grid) (9Ha Plots Wood Data Set)

PROJECT TITLE: Seedling and Sapling Dynamics

PROJECT DESCRIPTION: Studies of seedlings and saplings are and have been conducted on several landslides and plots on the LEF. The primary purposes are to study seedling recruitment and seedling and sapling growth and the effect of hurricane disturbance (specifically Hugo) on these processes as related to the degree of canopy disturbance, and the temporary reduction in shade from the defoliation of the canopy under distinct soil conditions.

9Ha Study

The primary purpose of this study is to look at seedling recruitment, and the growth of seedlings and saplings as it relates to the degree of canopy disturbance caused by Hurricane Hugo. Although all trees down to 1-cm dbh will eventually be identified and measured for the separate 16-ha grid project, the smallest trees will not be measured for at least a year, and seedling will not be included in the 16-ha grid program. The seedling/sapling plots in the 9-ha grid will allow us to follow early responses of seedlings and saplings to increased light. Tree maps for the 16-ha grid which will encompass the 9-ha grid) will eventually be used to determine the proximity of seed-source trees to each plot.

Treefall Pits Study

In this study, I compared seedling and sapling dynamics in soil pits and undisturbed forest floor, were both environment has experienced a temporary reduction in shade from the defoliation of the canopy during Hurricane Hugo (September 1989) but had soil conditions that were distinct. Soil pits were chosen as the microsite within the treefall gap most likely to differ in soil characteristics from the adjacent forest and most likely to alter plant establishment patterns. Soil mounds, important sites of establishment in some temperate forests (Webb 1999), erode quickly under the high rainfall conditions in Puerto Rico and were not considered in this study. I asked the following questions: (1) how does the soil physical environment differ between the soil pit and the forest floor?; (2) do tree species that have N-fixing symbionts influence soil nutrients or species composition of colonizers?, and (3) what are the consequences of uprooting and defoliation for populations of seedlings and saplings and for tree recruitment?

LTER CORE AREAS: (Annotate all that apply)

Primary Productivity

LEF LTER 1 RESEARCH TOPIC: (Annotate all that apply)

Gap Revegetation

We define a data file as a component of a data set. A data set can have only one data file or more. Basically, different data files have different data structures or format.
DATA SET FILES (SUBSETS):

Data File No.	Data File Identifier	On-Line Filename	Starting Date	Periodicity of sample	End Period
1	Wood fall from Hurricane Hugo in the 9ha Grid	9hwood.txt	June 6, 1990	Once in 1990, once in 1992	January 17, 1992

RESEARCH LOCATION: Nine hectare grid located at El Verde, LEF

INVESTIGATORS:  

PRINCIPAL INVESTIGATORS E-MAIL address

Nick Brokaw

nbrokaw@lternet.edu

OTHER RESEARCHERS E-MAIL address

Lawrence Walker	Lwalker@lternet.edu
D. Jean Lodge	Jlodge@lternet.edu
Bruce Haines	Bhaines@lternet.edu

CONTACT PERSONS E-MAIL address Phone Number (Include area code)

Nick Brokaw

nbrokaw@lternet.edu

(787)767-0350

SOURCE OF FUNDING (SPONSOR): LTER-NSF

DATA SET ABSTRACT: Purpose was to document vegetation damage and recovery following Hurricane Hugo.

DATA SET METHODS: Hurricane Hugo wood-fall estimates: Lenght of hurricane-associated dead wood greater than 1 cm diameter (hanging and downed) will be estimated by diameter class in each plot using a line-intercept technique. This measurement will be made once, in June of 1990. A meter tape will be stretched diagonally between corner poles in the plot, and two meter sticks will be placed diagonally at right angles to the tape. Both lenghts should be measured and recorded on the data sheet. The number of times branchs or logs cross the transect lines will be recorded by diameter class. A touch counts as a "hit" if the midline of the wood touches or crosses a transect line. Two additional transect lines will be used to increase the accuracy of the estimate. One of these is the nylon cord separating the seedling subplot within the 2x2 m plot. This cord is oriented N-S, and is approximately 2 m in length, but measure and record the length. Create a fourth transect line by placing the two meter sticks end-to-end, oriented N-S (i.e., parallel to the seedling (subplot), and located 0.5 m from the opposite side of the plot. Add the number of wood intersects with these transect lines to the previous two. Length of wood in each diameter class will be calculated by the Newman formula: Lenght = [pix number intesects x Area (=4m2)] divided by 2 x Sum lenght of the intercept lines. The diameter classes are 2-5 cm, >5-10. >10-15, >15-20, >25-30. All wood >30 cm diam will be measured at the intercept and recorded individually.

Summary of Plot Establishment:

Sixty 2x2 m seedling and sapling plots were established during May of 1990 in the 9-ha grid by Francisco Calderon and
Eduardo Flores. Plots are associated with appoximately every other grid pole, as described in the separate protocol
instructions. Plots are representative of habitat frequencies, topographic locations and aspect, but plots with > 50% bare
boulders, stream beds or trails were rejected. The corners of each plot are marked with 2 1/2 foot long PVC poles with fuchsia pink tops. Nylon string was tied around the perimeter. The inner corner of the plot is set 1+1 m away (usually N and E) from the grid pole to avoid foot traffic, and is marked with an aluminum tag saying: Brokaw 9-ha seed/sap plot, LTER, June 1990 plus the grid pole number. A 1/2 x 2m seedling subplot has been marked with nylon cord, beginning at the inner corner and oriented N-S. Flagging leading to plots is orange.

REFERENCES:

CROSS-REFERENCES (other data sets related to this one): LTERDBAS 37: Regeneration after Hurricane Hugo, woody species > 10 cm tall (9Ha grid, El Verde) (9Ha Plots Small Data Set); LTERDBAS 38: Regeneration after Hurricane Hugo, woody species > 1 m tall (9Ha grid, El Verde) (9Ha Plots Large Data Set); LTERDBAS 39: Regeneration after Hurricane Hugo woody species > 1m tall (9ha grid, El Verde)(Wood fall from Hurricane Hugo 9Ha Grid) (9Ha Plots Wood Data Set); LTERDBAS 40: Regeneration after Hurricane Hugo woody species > 1m tall (9ha grid, El Verde) Percent cover below 3m (9 ha grid, El Verde); LTERDBAS 113: Seedling and sapling dynamics of treefall pits and undisturbed florest floor in El Verde, Puerto Rico

SAMPLE LOCATION : N/A

STORAGE SITES (of data files): ITES – UPR Data Mngr.'s Cabinet DM 333-01, Drawer #1

INVESTIGATOR'S ASSIGNED KEYWORDS: Hurricane wood-fall; revegetation,hurricane damage, gap formation, LTER, forest recovery

LEF LTER OFFICIAL KEYWORDS (See table): 9HA GRID, TABONUCO, HURRICANE, TREEFALL, TREES, PEER REVIEWED JOURNAL

PUBLICATIONS :

DISSEMINATION: UNRESTRICTED

REASONS TO RESTRICT DATA IN THIS DATA SET BEYOND ITS TWO YEAR POLICY PERIOD*:

*WILL HAVE TO BE APPROVED BY LTER PRINCIPAL INVESTIGATORS: J. ZIMMERMAN, A. LUGO , D.J. LODGE

SITES DESCRIPTIONS:

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude

VARIABLES:

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1	1	1
ABBREVIATION (as it appears on the data file)	TransectPlot	Start_Date	Diag_I	Diag_II	Trans_I
NAME OF VARIABLE	Plot identifier	Start Date	Length of Diagonal I	Length of Diagonal II	Length of Transect I
DEFINITION OF VARIABLE	Sixty 2x2 m seedling and sapling plots, associated with appoximately every other grid pole and  representative of habitat frequencies, topographic locations and aspect. Format: A#, where A is in {A,...,K} and # in {1,...,11}.	Date of the day (in mm/dd/yyyy) when measurements of diameter class in each plot were made.	Measurement in meter of one diagonal of the plot as measured from one corner pole to the other.	Measurement in meter of the other diagonal of the plot as measured from one corner pole to the other.	Length of nylon cord oriented N-S and separating the seedling subplot within the 2x2 m plot.
UNIT			meter	meter	meter
PRECISION
RANGE OR LIST OF VALUES
DATA TYPE	alphanumeric	datetime	decimal	decimal	decimal
MISSING DATA CODES

VARIABLES:

VARIABLES:

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1	1	1
ABBREVIATION (as it appears on the data file)	20-25cm	25-30cm	gt30cm	Remarks	Observers
NAME OF VARIABLE	Diameter class 20-25cm	Diameter class 25-30cm	Diameter classes greater than 30cm	Remarks	Initial of the observers
DEFINITION OF VARIABLE	number of times that branchs or logs with diameter within 20-25cms cross the transect lines	number of times that branchs or logs with diameter within 25-30cm cross the transect lines	number of times that branchs or logs with diameter greater than 30cm cross the transect lines	Comments written by the observers or data gatherers at the field	List of full names or abbreviations of the observers
UNIT
PRECISION
RANGE OR LIST OF VALUES
DATA TYPE	decimal	decimal	decimal	alphanumeric	alphabetic
MISSING DATA CODES

COMPUTATIONAL METHODS:

DATE OF LAST REVIEW: June 19, 2008
DATE OF LAST ENTRY: 1992
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED ENTERED: 1995
FILED ON-LINE REVIEWED BY RESEARCHER 1995
FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdb39.doc
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 39
DOCUMENT TYPE: magnetic media
PRIORITY TO BE ENTERED: second

Rev. date of this form: 25 January 2001