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:

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

PROJECT TITLE: Meteorology and Hydrology at Bisley

PROJECT DESCRIPTION: PROJECT DESCRIPTION: Several meteorological parameters are being measured at Bisley since 1993. Correlations between elevation and stream-runoff and rainfall, elevation and air and soil temperature, and between trhoughfall and vegetation types have been found. These relationships are used inhydrologic and nutrient budgets as well as in environmental models .

Rainfall and Stream-runoff

Long-term rainfall and discharge data from the Luquillo Experimental Forest (LEF) were analysed to develop relationships between rainfall, stream-runoff, and elevation. These relationships were then used with a Geographic Information System (GIS) to determine spatially-averaged, mean annual hydrologic budgets for watersheds and forest types within the study area. Model estimates indicate that a total of 3864 mm/yy (444 hm3) of rainfall falls on the forest in an average year. The Tabonuco, Colorado, Palm and Dwarf Forest types receive an estimated annual rainfall of 3537, 4191, 4167, and 4849 mm/yy, respectively. Of the average annual rainfall input, 65% (2526 mm/yr) is converted to runoff and the remainding 35% (1338 mm.yr) is lost from the system by evapotranspiration and other abstractions. In comparison to other tropical forests, the LEF as a whole has more evapotranspiration than many tropical montane forests but less evapotranspiration than many lowland tropical forests.

Throughfall

Changes in the quantity and quality of precipitation as it passes through vegetative cover are important components of both hydrologic and nutrient budgets.

Throughfall over any period depends on the balance between precipitation, evaporation and canopy storage (Horton, 1919; Leonard, 1967; Rutter et al., 1972). If the watershed is divided into different vegetation types based on similarity in throughfall and steamflow, the total throughfall over the watershed can be expressed as:

(1) Pg = Sum( T n A n )+ Sum (Sm Dm)

Where Pg = total throughfall reaching the ground, Tn = canopy throughfall from vegetation type n, An = area of vegetation type n, Sm = stemflow from stem type m and Dm = number of stems in type m.

Using eqn. (1) to estimate total watershed throughfall becomes a problem of determining the minimum number of vegetation types necessary to describe the system at the required level of accuracy. In one of our studies, measured throughfall was compared with actual canopy and stem conditions to estimate the percentages of throughfall for different time periods was calculated by weighting the average throughfall and stemflow measured in representative areas of each vegetation type by the total area of that vegetation group.

Measurements reported here were made in two of the Bisley Research Watershed of the U.S. Forest Service. These adjacent watersheds drain 13.0 ha of highly dissected mountainous terrain that range in elevation from 265 to 455 m. Both watersheds are covered by Tabonuco type forests and were selectively logged at various times between 1860 and 1940 (Scatena, 1988).
The dominant tree in the watersheds in the Tabonuco ( Dacryodes excelsa ) which often comprises as much as 35% of the canopy ( Wadsworth, 1970). Structurally the forest has three dominant layers, a discontinuous emergent strata, a continuous upper stratum at 20 m, and an understory layer. Leaves are mesophyllous and often covered with epiphytic growth.

Air and Soil Temperature

The relationship between mean air temperature and elevation is a required parameter for some environmental models such as Zelig. Mean air and soil temperature measurements of 10 sites located along a windward elevation gradient from 153 to 1011 meters were used to develop relationships between mean air and soil temperature of and elevation. The regressions performed showed a linear relationship between both air and soil mean temperature and elevation. The equations:

(2) Mean Air Temperature (in C) = 26.4 -(0.00558 * elevation in meters) and

(3) Mean Soil Temperature (in C) = 25.6 - (0.00543 * elevation in meters)

best fit these relationships. The equation that best fits the mean soil temperature - elevation relationship includes all the stations. In contrast, the best equation for the mean air temperature - elevation relationship excluded both station located at Sabana.

LTER CORE AREAS: (Annotate all that apply)

Disturbance Patterns

Primary Productivity

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

Environmental Monitoring

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	Bisley Rain Gauge weekly measurements	bisleyANDr.txt	July 30, 1987	weekly	December 31, 2002

RESEARCH LOCATION: Bisley Watersheds, Towers, Luquillo Experimental Forest,P.R.

INVESTIGATORS:

PRINCIPAL INVESTIGATORS E-MAIL address

Fred Scatena

fns@sas.upenn.edu

OTHER RESEARCHERS E-MAIL address

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

Fred Scatena

fns@sas.upenn.edu

(809) 766-5335

SOURCE OF FUNDING (SPONSOR): USFS

DATA SET ABSTRACT AND METHODS: (See charts and map) Long-term rainfall and discharge data from the Luquillo Experimental Forest (LEF) were analysed to develop relationships between rainfall, stream-runoff, and elevation. These relationships were then used with a Geographic Information System (GIS) to determine spatially-averaged, mean annual hydrologic budgets for watersheds and forest types within the study area.
A significant relationship exists between: 1)elevation and mean annual rainfall; 2)elevation and the average number of days per year without rainfall; 3)annual stream runoff and the weighted mean elevation of a watershed, and 4)annual stream runoff and the elevation of the gaging station. A comparison of rainfall patterns between a high and a low elevation station indicated that both annual and seasonal variations in rainfall are similar along the elevational gradient. However, the upper elevation station had greater annual mean rainfall (4436 mm/yr) compared to 3524 mm/yr) while the lower station had a greater variation in daily, monthly, and annual totals.

Model estimates indicate that a total of 3864 mm/yy (444 hm3) of rainfall falls on the forest in an average year. The Tabonuco, Colorado, Palm and Dwarf Forest types receive an estimated annual rainfall of 3537, 4191, 4167, and 4849 mm/yy, respectively. Of the average annual rainfall input, 65% (2526 mm/yr) is converted to runoff and the remainding 35% (1338 mm.yr) is lost from the system by evapotranspiration and other abstractions. In comparison to other tropical forests, the LEF as a whole has more evapotranspiration than many tropical montane forests but less evapotranspiration than many lowland tropical forests.

DATA SET METHODS: Total rainfall is measured by three different devices: a plastic funnel collector projected above the canopy and connected to a ground level storage bottle by 25m of plastic tubing; a recording gage in a clearing adjacent to the watersheds; and for the last 8 months of the study from October 1, 1987 to October 1, 1988, recording gages located on a 25m canopy observation tower and on the adjacent forest floor. Both the funnel collector and the tower gages are located on the divide near the center of the combined drainages. All three rain gages recorded similar values. After testing several methods, gallon plastic jugs fitted with sealed 18 cm diameter screened funnels were used to measure throughfall. These bottles were found to be superior to trough and open can collectors since they are not subject to excessive losses by evaporation or raindrop splash.

Collectors were placed in randomly selected lines that were located throughout the watershed and transected ridges, hillslopes, gaps and stream channels. Each collector was sampled weekly and before and after numerous individual rainfall events. Since the collectors were sealed except for the 1-cm diameter funnel entrance, losses due to evaporation from the collectors were considered negligible

Funding for this study was provided by the USDA, Forest Service through the Luquillo Experimental Forest, Rio Piedras, Puerto Rico.

REFERENCES:

García-Martinó, A.R.*, G.S. Warner, F.N. Scatena, and D.L. Civco. 1996a. Rainfall, runoff, and elevation relationships in
the Luquillo Mountains of Puerto Rico. Caribbean Journal of Science 32:413-424.

T. Heartsill-Scalley, F.N. Scatena, C. Estrada, W.H. McDowell, and A.E. Lugo. 2007. Disturbance and long-term patterns of rainfall and
throughfall nutrient fluxes in a subtropical wet forest in Puerto Rico. Journal of Hydrology 333: 472– 485. (available at: http://www.sciencedirect.com/)

CROSS-REFERENCES (other data sets related to this one):LTEREDBAS26: Bisley Rainfall and Throughfall data; LTERDBAS29: Bisley daily rainfall (Bisley weekly environmental data); LTERDBAS 90: Bisley Tower I Meteorological data (Bisley Tower); LTERDBAS148: Bisley rainfall and throughfall, and chemistry of rainfall and throughfall;
Also see: Regression relationships of air temperature and elevation along an elevation gradient in the Luquillo Experimental Forest (LEF), Puerto Rico

SAMPLE LOCATION: USFS at San Juan, Puerto Rico

STORAGE SITES: Terrestrial Ecology, CEER, Data Mngr.'s Cabinet DM333-01, Drawer #1 rainfall; throughfall.

INVESTIGATOR'S ASSIGNED KEYWORDS: rainfall; throughfall

LEF LTER OFFICIAL KEYWORDS (See table): BISLEY WATERSHEDS, TABONUCO, CLIMATE, RAINFALL, PEER REVIEWED JOURNAL

PUBLICATIONS:
Scatena F.N. 1990. Watershed scale rainfall interception on two forested watersheds in the Luquillo Mountains of Puerto Rico. Journal of Hydrology 113:89-102

Schellekens J., Bruijnzeel L.A., Wickel A.J., Scatena F.N., Silver W.L., 1998. Interception of horizontal precipitation by elfin cloud forest in the Luquillo Mountains, Eastern Puerto Rico. First International Conference on Fog and Fog Collection, eds. Schenenauer and H.A. Bridgeman, pp.29-32, Vancouver, Canada

Schellekens J., Scatena F.N., Bruijnzeel L.A., 1999 Modeling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico. Journal of Hydrology. Vol. 225:168-184

Schellekens J., Bruijnzeel L.A., Scatena F.N., Bink N.J., Holwerda F., 2000. Evaporation from a tropical rain forest, Luquillo Experimental Forest, eastern Puerto Rico. Water Resources Research Vol. 36, No. 8:2183-2196

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: Bisley Watersheds, Towers, Luquillo Experimental Forest, P.R.

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1
ABBREVIATION (as it appears on the data file)	YEAR	MONTH	DAY	DATE(MM/DD/YYYY)
NAME OF VARIABLE	Year out/in	Month out/in	Day out/day	Date
DEFINITION OF VARIABLE	Year at which collectors were sampled on a weekly basis and before and after numerous individual rainfall events in (YYYY). No data in the given period is missing.	Month at which collectors were sampled on a weekly basis and before and after numerous individual rainfall events in (MM). No data in the given period is missing.	Month day at which collectors were sampled on a weekly basis and before and after numerous individual rainfall events in (DD). No data in the given period is missing.	Date, in the fromat of (mm/dd/yy) at which collectors were sampled ( on a weekly basis and before and after numerous individual rainfall events). No data in the given period is missing.
UNIT	N/A	N/A	N/A	N/A
PRECISION	N/A	N/A	N/A	N/A
RANGE OR LIST OF VALUES	{1987,..., 2002}	{1,..., 12}	{1,...31}
DATA TYPE	datetime	datetime	datetime	date
MISSING DATA CODES

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1
ABBREVIATION (as it appears on the data file)	RAINFALL_(MM)	THROUGHFALL_(MM)	THROUGHFALL_(%)
NAME OF VARIABLE	Weekly rainfall	Weekly throughfall	Calculated weekly throughfall percent
DEFINITION OF VARIABLE	Rainfall collected in plastic funnel projected above the canopy and connected to a ground level storage bottle by 25m of plastic tubbing	Canopy throughfall collected in gallon plastic jug fitted with sealed 18cm diameter screened funnel. Both collected on a weekly basis and before and after numerous individual rainfall events.	Canopy throughfall collected in gallon plastic / Rainfall collected in plastic funnel
UNIT	mm	mm	N/A
PRECISION	+ or - .01	+ or - .01
RANGE OR LIST OF VALUES
DATA TYPE	Decimal	Decimal	Decimal
MISSING DATA CODES	blank	blank	blank

COMPUTATIONAL METHODS:

DATE OF LAST REVIEW: June 19, 2008
DATE OF LAST ENTRY: Sep 6, 2000
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED Aug 28, 2000 (last version)
ENTERED: FILED 1990
ON-LINE 1996
REVIEWED BY RESEARCHER Aug 28, 2000
FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdb26.htm, data-Bis.htm
NAME OF DATA FILE: bisley&r.txt
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 26
DOCUMENT TYPE: magnetic media
PRIORITY TO BE ENTERED: N/A

Rev. date of this form: 8 June 2001