LUQ LTER DATA SETS DOCUMENTATION FORM

ON-LINE VERSION

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.

NOTES:

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DATA SET IDENTIFIER: Canopy Trimming Experiment (CTE) plant seedling measurements

PROJECT TITLE: Canopy Trimming Experiment (CTE)

PROJECT DESCRIPTION: This long-term experiment will increase the frequency of simulated hurricane effects above background levels to once every six years. The experiment will determine effects of repeated disturbance of the forest canopy and increased detrital inputs to the forest floor on germination, growth, survival, nutrient cycling, soil conditions, and trophic structure. Climate change models predict increased frequency and intensity of Caribbean hurricanes (Emmanuel 1987, Goldenberg et al. 2001), and our goal is to evaluate predictions regarding the effects of an increased rate of hurricane disturbance on tabonuco forest (Sanford et al. 1991). The experiment also is designed to decouple the effects of canopy disturbance (e.g. , light levels, temperature, moisture, etc. ) from those of increased detrital inputs on rates of detrital processing and resultant community and ecosystem processes. Manipulations and measurements of detrital processing, SOM, and soil properties associated with SOM will continue for at least three more funding periods (until 2024). In the short-term, we will use faunal manipulations nested within the canopy trimming experiment to measure the strength of interactions between autotrophic and detrital food webs in the context of hurricane-like disturbance. These results will be directed specifically at parameterizing the Trophic Interaction Model. This experiment also will provide a physical and intellectual focal point for the project participants.
The Canopy Trimming Experiment has two parts: 1) a forest canopy manipulation with measurements of coupled changes in microclimate, structure, and biota and their associated impacts on ecosystem processes, and 2) specific manipulations of the biota that assess the importance of components of the food web.

LTER CORE AREAS: (Annotate all that apply) (See online list)

Primary Productivity

Population Dynamics

Disturbance Patterns

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

Experimental Disturbance

Recovery-Gap Reveg

Disturbance

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	CTE Seedlings Measurements	CTESeedlingMeasurement.txt	June 5, 2003	Every 6-12 months	October 4, 2006

RESEARCH LOCATION: Block A: 30+ m West of western edge of Big Grid, on North and South side of Prieta stream, near Vogt old plots. Block B: 30+ m South of Big Grid, all plots along Oxcart Trail. Block C: 30+ m West of SE corner of Big Grid.

INVESTIGATORS:

SOURCE OF FUNDING (SPONSOR): NSF LTER

DATA SET ABSTRACT: Seedlings were measured before and after treatments to determine how alterations in canopy openness and detritus affect seedling densities and life histories (growth, mortality, recruitment). It was predicted that plots experiencing canopy openness with detritus removed would have the quickest increase in seedlings (recruitment and growth), especially of early successional (light demanding) species, such as Cecropia. Seedlings in plots that received no canopy manipulation but had detritus deposited is predicted to have near-total mortality initially (low light and high physical inhibition due to detritus). Treatment plots experiencing both canopy manipulation and addition of detritus would initially experience near-total mortality, with some light demanding seedlings establishing and growing through detritus with time.

DATA SET METHODS: In each of the five non-destructive (plant) subplots, one 1 x 3.5 m measurement area was established at a random location that was at least 75% boulder-free to measure seedlings (all vascular life forms <1 cm dbh at 1.3 m height). We identify each seedling to species, including trees, shrubs, herbs, vines, palms, orchids, and ferns. Seedlings ≥10 cm tall received a permanent tag, and height and diameter (measured above the root crown) was measured. Seedlings ≤10 cm were identified to species (if possible), counted, and this number was recorded, but were not tagged. Plot cover and litter depth were also measured in the 1 x 3.5 m area. Cover categories included:  litter, rock, bare soil, live trunk, dead trunk, and grass. Canopy photographs were taken with a Nikon Coolpix 4500 camera at 1 m height above, and in the center, of each seedling plot, as well as the corners and center of each 20 x 20 m plot. Photos were analyzed using Gap Light Analyzer, Version 2. Canopy cover and an index of light for each photo were determined.

REFERENCES:

CROSS-REFERENCES (other data sets related to this one): LTERDBAS #144: Canopy Trimming Experiment (CTE) Plants greater than 1 centimeter diameter at breast height (DBH)

STORAGE SITES(of data files):

INVESTIGATOR'S ASSIGNED KEYWORDS: disturbance, hurricanes, hurricane simulation, tabonuco forest, vegetation, plant growth, detritus, canopy openess

LEF LTER OFFICIAL KEYWORDS (See table): EL VERDE, CTE blocks, TABONUCO, DISTURBANCE, PLANT GROWTH, HIGHER PLANTS, PEER REVIEWED JOURNAL

PUBLICATIONS:

DISSEMINATION:

RESTRICTED _X__ UNRESTRICTED ___

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

*WILL HAVE TO BE APPROVED BY AT LEAST ONE LUQ LTER PRINCIPAL INVESTIGATORS: N. Brokaw, A. Lugo

SITES DESCRIPTIONS: Block A: Elevation (340-360); aspect SW-facing; Location 30+ m West of western edge of Big Grid, on North and South side of Prieta stream, near Vogt old plots. Block B: Elevation (450-485); aspect W-SW facing; Location 30+ m South of Big Grid, all plots along Oxcart Trail. Block C: Elevation (435-480 m); aspect West-facing; Location 30+ m West of SE corner of Big Grid.

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude

The following table displays the x and y coordinates in Puerto Rico Planar Coordinates:

BlockPlot	X	Y
A1	217379	54625
A2	217437	54631
A3	217423	54720
A4	217460	54684
B1	217824	54356
B2	217875	54344
B3	217913	54278
B4	217970	54217
C1	217878	54476
C2	217933	54476
C3	217998	54480
C4	218094	54544

VARIABLES (ATTRIBUTES):

File Name or # above (all in which the variable appears)	1	1	1	1	1
AbbreviationAbbreviation(as it appears on the data file)	BLOCK	PLOT	SUBQUAD	SECTION	TAG
NAME OF VARIABLE	Block Identifier	Plot Identifier	Subplot Identifier	Section identifier	Tag number
DEFINITION OF VARIABLE	Name given to a collection of 4-20m X 20m plots. No data is missing in this field.	Name given to a 20m X 20m plot. No data is missing in this field.	Name given to a 1.0 m x 3.5 m subquadrat within a nondestructive plant subplot. No data is missing in this field.	Sections numbers (1, 2, or 3) that divide the 1.0 m x 3.5 m subquad. No data is missing in this field.	Number on a metal tag specifying each seedling. Each tag is attached to seedling with string, and metal tag also states the Plot-Subquad number. In order for a seedling to receive a tag, it must be at least 10 cm tall. No data is missing in this field.
UNIT
PRECISION
RANGE OR LIST OF VALUES	A=West of western edge of Big Grid plot; B = South of Big Grid; C = West of SE of Big Grid	1,...,4	1...,5	1...,3	1,...
DATA TYPE	alphabetic	integer	integer	integer	integer
MISSING DATA CODES

RIABLES (ATTRIBUTES):

File Name or # above (all in which the variable appears)	1	1	1	1	1
AbbreviationAbbreviation(as it appears on the data file)	SPECIES	HEIGHT	DIAMETER	LESSTHAN10CM	V_T_F_H_S_G
NAME OF VARIABLE	Species code	Seedling height	Diameter of seedling	Seedlings with heights of <10 cm	Seedling life form
DEFINITION OF VARIABLE	A 6 letter code with first 3 letters representing the genus, and second 3 representing the species according to Charlotte Taylor's species description	Distance from ground to apical meristem. For vines the height is measured to the base of the tallest leaf blade.	Diameter of seedling just above the root crown	Count of the number of seedlings with heights of <10 cm above the ground. This will be a species-specific count	V=vine, T=tree, F=fern, H=herb, S=shrub, G=grass
UNIT		centimeters	centimeters
PRECISION		.5	.01
RANGE OR LIST OF VALUES					V=vine, T=tree, F=fern, H=herb, S=shrub, G=grass
DATA TYPE	alphabetic	decimal	decimal	integer	alphabetic
MISSING DATA CODES	Blank	blank	blank	blank	blank

VARIABLES (ATTRIBUTES):

File Name or # above (all in which the variable appears)	1
AbbreviationAbbreviation(as it appears on the data file)	COMMENTS
NAME OF VARIABLE	Additional observations
DEFINITION OF VARIABLE	Additional comments plus the point of measurement if different than specified in 'height' or 'diam'
UNIT	N/A
PRECISION	N/A
RANGE OR LIST OF VALUES
DATA TYPE	alphanumeric
MISSING DATA CODES	blank

COMPUTATIONAL METHODS:

Variable Name	Formula

FOR DATA MANAGER USE ONLY

DATE OF LAST REVIEW: April 7, 2009

DATE OF LAST ENTRY:

STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED: September 26, 2003
ENTERED: February 17, 2006
FILED ON-LINE: February 23, 2006
REVIEWED BY RESEARCHER:

FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdb143.htm
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 143
DOCUMENT TYPE: binary only
PRIORITY TO BE ENTERED: N/A