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(Data, Abstract, Methods, Variables)

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

DATA SET IDENTIFIER: Litterfall in tabonuco (subtropical wet) forest in the Luquillo Experimental Forest, Puerto Rico (MRCE Litterfall data)

PROJECT TITLE: Nutrient Cycling in Tabonuco Forest (MRCE/LTER Litterfall Nutrient Fluxes, and Extractable Soil versus Microbial Biomass Nitrogen)

PROJECT DESCRIPTION: Understanding the long-term impact of deforestation on ecosystem structure and function of tropical forests may aid in designing future conservation programs to preserve biodiversity and sustain ecosystem productivity. We examined forest structure, tree species composition, litterfall (fine and coarse) due to Hurricane Hugo and subsequent fine annual litterfall inputs, litterfall rate, and leaf litter decomposition. The experiment was initiated by the MRCE (Minortity Research Centers of Excellence) program, and continued by the LTER. In addition to measuring nutrient fluxes from litterfall and decomposition, we measured KCl-extractable soil nitrogen in ammonium and nitrate forms to determine the effects of complete fertilization and removal of hurricane debris.

History of litterfall, decomposition and soil nitrogen availability studies (MRCE experiment) at the Luquillo Experimental Forest (LEF):

The Minority Research Centers of Excellence (MRCE) experiment was designed originally to determine whether forest productivity was limited by nutrient availability, genetic constraints or climatic variables along a steep environmental gradient in the Luquillo Mountains of Puerto Rico. Comparisons were made between dwarf forest at 500 m elev. and tabonuco forest from 300-400 m elev. There were two main experiments in the original design: 1) forest fertilization (complete versus none); 2) transplant experiments using common gardens at high and low elevation, with and without wind protection at high elevation. In addition, phenology of leaves was studied in the dwarf forest to determine the longevity of leaves in the canopy.

Hurricane Hugo struck in September 1989, following a year of pre-treatment measurements and just as the forest plot fertilization experiments were to begin, and deposited a year and a half of annual above ground litter inputs of phosphorus on the forest floor in green leaf litter (Lodge et al. 1991).  As phosphorus is thought to be the most limiting element, this necessitated the addition of a hurricane debris-removal treatment as a second type of control in the lower elevation tabonuco forest. Furthermore, the hurricane changed the nature of the study into one of looking at changes in forest composition and the recovery of forest productivity in response to fertilization and hurricane debris-removal. Seedling, sapling, herbaceous plant, and fern responses, as well as measurements of light availability and canopy closure were added to the originally planned measurements of tree diameter growth, leaf litter production, and fine root production and turnover. Funding for continued studies of the MRCE plots ended in 1998, but they were of such great value as a long-term experiment that they were incorporated into the LTER program. Another hurricane in 1998 (Hurricane Georges) presented an opportunity to look at the effects of removing only the woody debris (in new plots) versus removing all hurricane debris.

The leaf decomposition experiment was originally designed to examine short-term disappearance of foliage from three important montane species: Prestoea montana (R. Grah.) Nichols, Dacryodes excelsa (Vahl.), and Cyrilla racemiflora. Hurricane Hugo (August, 1989) provided a unique opportunity to study effects of this type of natural disturbance on decomposition. The study was repeated in 1990 as part of the LTER, with some changes in the design that allowed for comparisons of short -term foliar litter biomass and nitrogen dynamics: (1) among the three species, (between the colorado and tabonuco forest types, (3) between riparian and upland sites, and (4) between pre- and post-hurricane environments.

LTER CORE AREAS: (Annotate all that apply)

Primary Productivity

Organic Matter Accumulation

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

System Properties

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	El Verde Research area (1990 - 1999)	evlit90-99.txt	3/26/90	Every 2 weeks	12/28/99
2	El Verde Research area (2000-)	evlit2000.txt	1/11/2000	Every 2 weeks	12/23/2002
3	Pico del Este Research area (1990 - 1999)	pelit90-99.txt	4/02/90	Every 2 weeks	12/21/99
4	Pico del Este Research area (2000-)	pelit2000.txt	01/04/00	Every 2 weeks	10/29/2008 (ongoing)
5	El Verde Research area Summary	ev-summary.txt	3/26/90	Every 2 weeks	12/23/02
6	Pico del Este Research area Summary	pe-summary.txt	4/02/90	Every 2 weeks	12/30/02

RESEARCH LOCATION: El Verde Research and Pico del Este area ( See attached map)
 

INVESTIGATORS:

PRINCIPAL INVESTIGATORS E-MAIL address

Alonso Ramirez

aramirez@ites.upr.edu

OTHER RESEARCHERS E-MAIL address

Xioming Zou	xzou@lternet.edu
Jess Zimmerman	jzimmerman@lternet.edu
Ligia Lebron	llebron@lternet.edu
Matt Warren	mwarren@lternet.edu

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

Alonso Ramirez

aramirez@ites.upr.edu

(787) 764-0000 Ext. 7781

SOURCE OF FUNDING (SPONSOR): LTER, NSF, MRCE ended 1998 and the project was assimilated by the LUQ LTER Program.

DATA SET ABSTRACT: Treatments common to both sites are quarterly fertilization (macro- and micronutrients) and unmanipulated. At El Verde, a third set of plots was subject to a one time removal of litter and woody debris generated by Hurricane Hugo (September 1989). Data at the El Verde Plots were gathered until December 22, 2003. The following table offers a map of the treatments performed at the plots:

Table 1. Quarterly fertilization (macro- and micronutrients) and unmanipulated

Site	Block	Plot	Treatment
El Verde	1	1	L	Where, L= Total litter removal once following hurricane Hugo, and once again following hurricane Georges. F= fertilization C= Controls T= Total litter removal following hurricane Georges ONLY (new plots after Georges) W= "Extra" control plots up to hurricane Georges, then after hurricane Georges, Coarse Woody Debris (wood) removal only. PE = Pico del Este area NA= Not apllicable; blocks do not exist at the PE area
El Verde	1	2	F
El Verde	1	3	C
El Verde	1	4	W
El Verde	1	5	T
El Verde	2	1	F
El Verde	2	2	W
El Verde	2	3	T
El Verde	2	4	L
El Verde	2	5	C
El Verde	3	1	T
El Verde	3	2	W
El Verde	3	3	L
El Verde	3	4	C
El Verde	3	5	F
El Verde	4	2	L
El Verde	4	3	C
El Verde	4	5	F
PE	NA	1, 3, 6, 8, 9, 12	C
PE	NA	2, 4, 5, 7, 10, 11	F

We have been recording litterfall in tabonuco forest near El Verde Field Station to investigate controls on primary productivity following hurricane damage. Plots in three treatments replicated in four blocks spread throughout the 70 ha El Verde Research Area have been monitored since March 1990, approximately six months after Hurricane Hugo removed the canopy from the forest. The three treatments are control plots, plots in which all hurricane debris (and standing stocks of litter) was removed from the forest floor within one month of the hurricane, and fertilized in which a complete mixture of supplemental nutrients are spread on the plots every three months (see Zimmerman et al. 1995, Walker et al. 1996 for details).

DATA SET METHODS: Plot layout at El Verde is a randomized block design (see map). Plots are 20x20 m square with 10x10 m inner measurement plots. Ten baskets 0.16 m ² in area were randomly placed in each measurement plot. (See MRCE UPDATE REPORT for details on the changes in the methodogy).

At Pico del Este, 12 plots have been randomly assigned to control and fertilizer treatments(see map). Plots are 14x9 m with 10x4 m inner measurement plots. Six baskets were randomly placed in each measurment plot. Litter is collected fortnightly at each site, refrigerated until transfer the laboratory in San Juan. Each sample is dried at 60 C, sorted into leaves, wood, and miscellaneous components and weighed.

Originally, each basket sample was proccessed separately, but all samples within a plot are now combined for processing (in effect since September 1993).

Additional control plots ("new control") were added in Block 1 and 2 in late 1991. Plots measure 20 x 20 m with an inner 10 x 10 m measurement plot into which 10 baskets 40 x 40 were placed. Baskets are emptied every two weeks. Material in the baskets is then sorted into leaves, wood, and miscellaneous fractions, dried at 60 C, and weighed

Since August 2, 2000 for Pico del Este Plots and September 9, 2000 for El Verde plots, the litterfall samples are being sorted by leaves, wood, and miscelaneous, but leaves are further sorted by species on each of the plots. The sorted material is weighted, the weights of the leaves are reported by species, and the wood and miscelaneous weights are reported by plot. The species that are accounted for in the El Verde case are: Dacrioydes excelsa (DACEXC),  Manilkara bidentata (MANBID), Cecropia Schreberiana (CECSCH),  Buchenavia capitata (BUCCAP), Sloanea berteriana (SLOBER), and others. In the Pico del Este case all species encountered are accounted for.

Data Management Issues: This project became part of the LTER program in 1998. Previous to this, the data set was catalogued in the LEF Data Set Catalog (LEFDSET1) with Record # 93. Now is part of the LTER Catalog (LTERDBAS) as Record #111.

Due to the change in methods in collecting the data (see Methods), since August 2 and September 19 the structure of the El Verde and Pico del Este files have changed, respectively. Six columns were added, one for each accounted species, in the El Verde File, and one column

REFERENCES:
Zimmerman, J.K., W. M. Pulliam, D.J. Lodge, V. Quiñones-Orfila, N. Fetcher, S. Guzmán-Grajales, J.A. Parrotta, C.E. Asbury, L.R. Walker, and R.B. Waide 1995. Nitrogen immobilization by decomposing woody debris and the recovery of tropical wet forest from hurricane damage. Oikos 72:314-322

CROSS-REFERENCES (other data sets related to this one): LTERDBAS#51: MRCE/LTER Soil and Microbial Biomass Nitrogen; LTERDBAS #93: Litter decomposition in tabonuco forest before Hugo; LTERDBAS #94: Litterfall of the tabonuco forest before Hurricane Hugo; LTERDBAS #95: Litterfall along topographic gradients at lower Bisley; LTERDBAS #111: Litterfall in tabonuco (subtropical wet) forest in the Luquillo Experimental Forest, Puerto Rico (MRCE Litterfall data); LTERDBAS #115: Short-term disappearance of foliar litter of three tree species native to rain forest of Puerto Rico

SAMPLE LOCATION: N/A

STORAGE SITES (of data files): DM 333-02 Drawer #1

INVESTIGATOR'S ASSIGNED KEYWORDS: Luquillo Experimental Forest (LEF), tropical wet forest, nutrient cycling, primary productivity, litterfall.

LEF LTER OFFICIAL KEYWORDS (See table): EAST PEAK, EL VERDE, MRCE, TABONUCO, LITTER FALL, PRIMARY PRODUCTION, TREES, PEER REVIEWED JOURNAL

PUBLICATIONS:
Fetcher, N., R.A. Cordero, and J. Voltzow. 1999. Lack of ecotypic differentiation: Plant response to elevation, population origin, and wind in the Luquillo Mountains, Puerto Rico. Biotropica 32:225-234

Walker, L.R., J.K. Zimmerman, D. Jean Lodge, and S. Guzman-Grajales. 1996. An altitudinal comparison of growth and species composition in hurricane-damaged forests in Puerto Rico. Journal of Ecology 84:877-889.

Zimmerman, J.K., W.M. Pulliam, D.J. Lodge, V. Quinones-Orfila, N. Fetcher, S. Guzman-Grajales, J.A. Parrotta, C.E. Asbury, L.R. Walker, and R.B. Waide. 1995. Nitrogen immobilization by decomposing woody debris and the recovery of tropical wet forest from hurricane damage. Oikos 72:314-322.

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: N. BROKAW, A. LUGO

SITES DESCRIPTIONS: El Verde research area: This area is located at about 400 m.a.s.l. at 18° 20' N, 65° 49' W, in the Luquillo Experimental Forest, Puerto Rico. Annual rainfall is 350 cm distributed more or less evenly throughout the year. The site lies within Holdridge's subtropical wet forest. Forest in the region are relatively undistributed foress dominated by tabonuco (Dacryodes excelsa), Manilkara bidendata, Sloaena berteriana, and secondary forests dominated by Cesarea arborea.

Pico del Este research area: This area is located at about 1000 m.a.s.l. at 18°16'N, 65°46'W, in the Luquillo Experimental Forest, Puerto Rico. Annual rainfall is 420 cm, a large proportion of which is in the form of fog and mist. The site lies within Holdridge's low montane forest. The forest is cloud forest (also called elfin or dwarf forest) dominated by Tababuia rigida, Ocotea spathulata, and Eugenia borinquensis.

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude
El Verde	18°19' N	65° 49' W
Pico del Este	18° 16' N	65° 45' W

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1,2,3,4,5,6	1,2,3	1,2,3,4,5,6	2,3	2,3	2,3
ABBREVIATION (as it appears on the data file)	Date	Block	Plot	Dacexc(g)	Manbid(g)	Cecsch(g)
NAME OF VARIABLE	Date	Block at El Verde study area	Plot at study area	Weight of leaves of Dacryodes excelsa species	Weight of leaves of Manilkara bidentata species	Weight of leaves of Cecropia schreberiana species
DEFINITION OF VARIABLE	Date of collection in Mm/dd/yyyy format. No data are missing in this field.	a Roman number representing a 20x20 m square with 10x10 m inner measurement plots (see a Figure1.jpg). No data are missing in this field.	A cardinal number representing a with 10x10 m inner measurement plot (in a Block in the El Verde area) or a 14x9 m measurement area with 10x4 m inner plots (in Pico del Este area) (See Table 1 in Abstract section or Page). No data are missing in this field.	Weight of each sample's leaves of Dacryodes excelsa species, after dried at 60 C and sorted into components. Data field is left blank when data is missing.	Weight of each sample's leaves of Manilkara bidentataspecies, after dried at 60 C and sorted into components. Data field is left blank when data is missing.	Weight of each sample's leaves ofCecropia schreberiana species, after dried at 60 C and sorted into components. Data field is left blank when data is missing.
UNIT				grams	grams	grams
PRECISION				.01	.01	.01
RANGE OR LIST OF VALUES		I, II, III, IV	El Verde = 1, ..., 5; PE = 1, ..., 12 (NorthWest to NorthEast)
DATA TYPE	datetime	alphabenumeric	integer	decimal	decimal	decimal
MISSING DATA CODES

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	2,3	2,3	4,5,6	3,4	1,2,4,5	1,2,3,4,5,6	1,2,3,4,5,6
ABBREVIATION (as it appears on the data file)	Buccap(g)	Slober(g)	Species	Leaves(g)	Other leaves (g)	Total leaves(g)	Wood(g)
NAME OF VARIABLE	Weight of leaves of Buchenavia capitata species	Weight of leaves of Sloanea berteriana species	Species name	Weight of specific species' leaves	Weight of other leaves in sample from a plot	Sum of weight of all leaves in plot	Weight of Wood
DEFINITION OF VARIABLE	Weight of each sample's leaves of Buchenavia capitata species, after dried at 60 C and sorted into components. Data field is left blank when data is missing.	Weight of each sample's leaves of corresponding species, after dried at 60 C and sorted into components. Data field is left blank when data is missing.	Species name whose weight of leaves were weighted. Data field is left blank when data is missing.	Weight of specific species' leaves in sample from a plot. Data field is left blank when data is missing.	Weight of each sample's remaining leaves after extracting specific species' leaves from a plot. Data field is left blank when data is missing.	Sum of all five species' leaves weights plus "Other leaves(g)" in the El Verde data and "Other leaves(g)" and "Leaves(g)" in the Pico del Este data. Data field is left blank when data is missing.	Weight of each sample's wood after dried at 60 C and sorted into components. Data field is left blank when data is missing.
UNIT	grams	grams		grams	grams	grams	grams
PRECISION	.01	.01		.01	.01	.01	.01
RANGE OR LIST OF VALUES
DATA TYPE	decimal	decimal	alphabetical	decimal	decimal	decimal	decimal
MISSING DATA CODES

Variables (Continues):

FILE NAME OR #ABOVE (all in which the variable appears)	1,2,3,4,5,6	1,2,5	1,2,3,4,5,6	4	1,2,3,4,5,6	1,2,3,4,5,6
ABBREVIATION (as it appears on the data file)	Miscellaneous(g)	Fruits_seeds_flowers(g)	Total(g)	Days_since_last_collection	Baskets_Collected	Comments
NAME OF VARIABLE	Weight of Miscellaneous	Weight of fruits, seeds, and flowers in sample	Weight of Total leaves, Wood, and Miscellaneous	Days since last collection	Number of baskets sampled	Comments about samples
DEFINITION OF VARIABLE	Weight of each sample's miscellaneous litterfall after dried at 60 C and sorted into components. Data field is left blank when data is missing.	Weight of each sample'sfruits, seeds, and flowers after extracting specific species' leaves. Data field is left blank when data is missing.	Sum of Total leaves, Wood, and Miscellaneous. Data field is left blank when data is missing.	Number of days since the last collection of litterfall from the baskets.	Number of baskets sampled from each plot (from which the litterfall was collected). Usually constant, 10 from El Verde, and 6 from Pico del Este, but sometimes some "missing". Data field is left blank when data is missing.	Comments and/or observations about sampling and/or lab processes. When sample did not include literfall from one basket, basket number was reported as "missing", when basket did not contain any litterfall at sampling time, basket is reported as "empty". . Data field is left blank when data is missing.
UNIT	grams	grams	grams	number
PRECISION	.01	.01	.01
RANGE OR LIST OF VALUES					El Verde = 0,...,10 PE = 0, ..., 6
DATA TYPE	decimal	decimal	decimal	integer	integer	alphanumeric
MISSING DATA CODES

COMPUTATIONAL METHODS:

Variable Name	Formula
Total leaves(g) (in El Verde data)	Dacexc(g) + Manbid(g) + Cecsch(g) + Buccap(g) + Slober(g) + Other Leaves(g)
Total leaves(g) (in Pico del Este data )	Leaves(g) + Other Leaves(g)
Total	Total leaves(g) + Wood(g) + Miscellaneous(g)

DATE OF LAST REVIEW: May 12, 2009
DATE OF LAST ENTRY: 2003
STAGE OF DATA SET MANAGEMENT (dates):
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED: March 19, 1993
CATALOGUED: 1993
ON-LINE: May 1, 1997
REVIEWED BY RESEARCHER: January 29, 1997
FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdset193.doc,htm
NAME OF ON - LINE CATALOG: LTERDBAS (previously LEFDSET1) 
RECORD #: 111 (previously 93)
DOCUMENT TYPE: magnetic media
PRIORITY TO BE ENTERED: second

Rev. date of this form: 24 January 2001