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 paraghaphs 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: Effect of plant density and light availability on leaf damage in Manilkara bidentata

PROJECT TITLE: Herbivory

PROJECT DESCRIPTION: Long-term experiments associated with herbivory, a process which under certain circumstances may be an important regulator of detrital processing, has started at El Verde only since 2002. In addition to continuing long-term vegetation measurements will be conducted to determine long-term patterns of herbivory in two ways. As in most tropical forests, herbivores mainly eat young leaves (Coley & Barone 1996), which flush during May and June in the tabonuco forest or following disturbance (Angulo-Sandoval & Aide 2000). We will measure percent herbivory on new leaves of focal species marked each year in May and June. The second measurement will be of inputs of green leaf litter and insect frass to the forest floor. These measures will be used to gauge the changes in rates of herbivory during recovery from disturbance, with the ultimate goal of evaluating the role of herbivory in succession.

In addition, herbivory manipulations (autotroph-based food web) will be conducted within the main treatments of the Canopy Trimming Experiment. This experiment will employ small-scale mesocosms and removal of organisms to isolate the potential effects of food web components thought to influence ecosystem processes. Because of the intense maintenance requirements of these manipulations, they will be conducted for only two years.

Currently the following cross-site project is conducted at LUQ: "Canopy herbivory and soil processes in a temperate and tropical forest".

Three short term experiments have been conducted at Luquillo on herbivory: one to determine the importance of food availability on herbivory, leaf phenology and leaf damage; another to dermine the effect of group feeding for a specific species, and a last one to determine the effect of plant density on herbivory.

LTER CORE AREAS: (Annotate all that apply)

Population Dynamics

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

Disturbance regime

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): herbivory on adut trees and saplings of Manilkara bidentata (adulthbv.txt)

Data File No.	Data File Identifier	On-Line Filename	Starting Date	Periodicity of sample	End Period
1	Leaf damage in Manilkara bidentata	adulthbv.txt	April 1, 1995	monthly	March 31, 1996

RESEARCH LOCATION: Hurricane Recovery Plot (Big Grid) at El Verde

INVESTIGATORS:

PRINCIPAL INVESTIGATORS	E-MAIL address
María del Pilar Angulo	manilkara1@hotmail.com
Mitchell Aide	maide@upracd.upr.clu.edu

OTHER RESEARCHERS	E-MAIL address

CONTACT PERSONS E-MAIL	address	Phone Number (Include area code)
Mitchell Aide	maide@upracd.upr.clu.edu	(787) 764-0000 Ext. 2580

SOURCE OF FUNDING (SPONSOR): NSF-LTER

DATA SET ABSTRACT: Variation in herbivory is often associated with plant density and light environment. To determine the effect of these variables on herbivory we studied leaf production and herbivory on saplings, juveniles and adults of Manilkara bidentata (Sapotaceae) in the Luquillo Experimental Forest (LEF), Puerto Rico. The major herbivore of M. bidentata is microlepidoptera leaf miner (Acrocercopssp.; Gracillariidae). To determine the effect of plant density on herbivory, 24 - 20 x 20 m plots were established and the density of saplings, juveniles and adults were determined. Leaf production, herbivory and growth were measured on all saplings in the plots. In addition, plant density was determined in 8-20 x 20 m plots surrounding the 24 focal plots. The effect of light environment was determined by comparing leaf phenology, leaf quality and herbivory in the vertical and horizontal profile. Sapling density in 60 x 60 m plots was associated with increased levels of herbivory. In the vertical profile, leaf production was continuous in the canopy and synchronous for juveniles and saplings and herbivory increased from the canopy (1.3%) towards the understory (35.6%). In the horizontal profile leaf production was related with the light environmen. Saplings in low light environment produced leaves in June, while plants in gaps had a broader peak of leaf production. Differences in leaf phenology did not result in differences in herbivory possibly because there was high variation in herbivory among leaves. Although many saplings lost more than 80% of new leaf area, there was no detectable effect on plant growth.

DATA SET METHODS: Study area. The study was conducted in a 16 hectare plot, in the Luquillo Experimental Forest (LEF), within the Caribbean National Forest in northeastern Puerto Rico (180^o 20' N, 65^o 49' W)(Waide and Reagan 1996). The study area is near El Verde Research Station (350 m) on the northwest slope of the LEF. The forest is classified as subtropical wet forest and the dominant tree species are Dacryodes excelsa, Prestoea montana, Casearia arborea, Inga laurina, Manilkara bidentata, and Sloanea berteriana (Zimmerman et al. 1994). Average height of the forest canopy is 20 m with few emergent trees (Waide and Reagan 1996). Mean annual precipitation is 3460 mm (McDowell and Estrada-Pino 1988), and although January to April is the period of lowest precipitation, monthly means are usually greater than 100 mm /month (Brown et al. 1983) and evapotranspiration is lower than precipitation throughout the year (Waide and Reagan 1996). Mean monthly temperatures range between 21-25^o C (Brown et al. 1983).

The 16 ha plot was established in 1990. The plot was divided in 20 x 20 m plots, and all plants greater than 1 cm in dbh were marked. The forest composition within the plot varied due to previous land uses. Land uses in the northern part of the plot included a coffee plantation, selective logging, charcoal production, and some areas were completely cut. The southern part of the plot received much less human impact and was mainly limited to some selective logging and charcoal production. Major human impacts were eliminated in the 1950's when this area was incorporated into the Luquillo Experimental Forest (García and Scatena 1994). These different land use patterns have affected the distribution of plant species in the forest. Some species are more common in the southern part of the grid (e. g. Manilkara bidentata ) whereas others are more common in the northern part (e. g. Casearia arborea) (Zimmerman, personal communication).

Study species

Manilkara bidentata (A. DC.) A. Chev. (Sapotaceae), is a dominant species in the LEF. It is a shade tolerant species and can grow to 30 m in height (Crow 1980). M. bidentata ranges from near sea level to 600 m and in the LEF it is mainly associated with Dacryodes excelsa, Sloanea berteriana and Buchenavia capitata (You 1991). M. bidentata can be found throughout the West Indies, Panamá, Colombia, Venezuela, Guianas, Perú, Ecuador and northern Brazil (Little and Wadsworth 1989).

The principal herbivore of M. bidentata is a microlepidopteran, Acrocercops sp., (Gracillariidae) (Davis personal communication). The larval stage is a leaf miner that feeds on young leaves and creates a blotch mine on the upper surface of the leaf. Larvae have two distinct forms and habits. The early sap-feeding stage has a flattened, apodal body and highly specialized mouthparts. Larvae continuously move the mouthparts to increase the size of the mine in the first few layers of subepidermal parenchyma cells without ingesting any solid tissue (Davis 1987). After 3 or 4 days larval morphology and behavior change. The larvae become cylindrical with a round head, chewing mouthparts and protolegs. During this period the larvae feed on palisade parenchyma cells and deposit frass throughout the mine and do not cross the midrib. Around day ten larvae stop feeding and emerge from the blotch mine and pupate. After 12-16 days the adult emerges (Opler 1974, Angulo- Sandoval personal observations). Adults are 1 cm long (Angulo-Sandoval personal observation) and are diurnal (Davis, personal communication). The eyes are red and the body is golden with brown spots on the front wings. The hind wings are very narrow and have hair-like projections (Angulo-Sandoval personal observation).

Data collection and analyses

Leaf phenology and herbivory. In April 1995, 212 saplings of M. bidentata (6-250 cm) were marked. Number of leaves, height and diameter at the base were recorded and remeasured in April 1996. In April 1995, five adult trees near a 20 m tower and 5 adults and 20 juveniles (2.6 - 5 m) in the 16 ha plot were marked for leaf phenology and herbivory census.

Leaf phenology and herbivory were measured in two different ways based on accessability. Every month, new leaves (maximum of 10) were marked with plastic colored wires on all saplings and 10 branches on each of the five adult trees near the tower. A month later, when leaves were fully expanded, leaf area and area damaged were measured using a plastic grid. For the remaining 5 adult trees and 20 juveniles, the number of leaves produced and herbivory were estimated using binoculars. The number of new leaves was counted monthly and percent herbivory was visually estimated by dividing each leaf in four sections and estimating the total damage (Nuñez-Farfán and Dirzo 1988).

The annual pattern of leaf production, for all individuals within each size class (saplings, juveniles, adults), was obtained by using the average leaf production of individuals in every month. Leaves produced within a month by a single individual were considered a single event (leaf cohorts). Monthly percent herbivory was calculated for each leaf cohort. Total damaged area on marked leaves was divided by the total potential leaf area. If a leaf was missing, the average size of the remaining leaves was calculated and this area was added to the total damaged area and to the total potential leaf area. Missing leaves could not be detected on the five adults and 20 juveniles that were visually censused, but leaves with high levels of herbivory (>90%) often remained on the plant.

Density effect. To determine the effect of density on herbivory a distribution map of adult M.bidentata (Zimmerman, unpublished data) was used to select 12 - 20 x 20 m low density plots (< 3 adults) and 12 high density plots (3 adults). A total of 212 saplings were located in the 24 plots. In addition, the density of juveniles (height- 2.6-5.0 m) was determined for each plot. To determine if plant density at different spatial scales affected levels of herbivory, saplings, juveniles and adults densities were measured in the eight plots that surrounded each of the 24 focal plots (60 x 60 m plot).

Stepwise regressions (Statistix 1996) were performed to determine the effect of plant density on herbivory. The independent variables were: plant density of saplings (6 -250 cm), juveniles (2.6-5.0 m), and adults in the 20 x 20 m and 60 x 60 m plots.

Light effect. Light environment for all saplings was estimated by determining the number of vegetation layers above each plant (0 - 3). In addition, the light intensity (photon flux density) was measured above 20 plants in each category with a Li-cor photometer (Quantum sensor) to corroborate the precision of the vegetation layer measurements. Leaf phenology was compared between saplings, juveniles and adults (vertical profile) and between saplings in different light environments (horizontal profile). The Kolmogorov-Smirnov test (Ott 1993) was used to compare the distributions of leaf phenology.

Within each size class, monthly levels of herbivory were compared. In the vertical profile, herbivory was compared between saplings, juveniles, lower branches of adults and upper branches of adults. In the horizontal profile, herbivory was compared between individuals in the four light environment catagories. The Kruskal Wallis test was used for all comparisons.

Sapling growth. The effect of herbivory and light environment on plant growth was determined using the 100 individuals that were followed for two years. The residuals from the regression between the initial and final height and the initial and final diameter of each plant were calculated and used as growth values. A third growth residual was obtained from the regression between the initial number of leaves and the total number of leaves produced. These measures of sapling growth were calculated for the secondary year and were correlated with levels of herbivory during the first year and light environment.

REFERENCES:
Brown, S., A. E. Lugo, S. Silander and L. Liegel. 1983. Research history and opportunities in the Luquillo Experimental forest. General Technical Report No. SO-44, U. S. Department of Agriculture Forest Service. Southern Experimental Station, New Orleans, Louisiana, USA.

Crow T.R. 1980. A rainforest chronicle: a 30-year record of change in structure and composition at El Verde, Puerto Rico. Biotropica 12:42-55

García-Montiel D., Scatena F.N 1994. The effect of human activity in the structure and composition of a Tropical forest in Puerto Rico. For Ecol Monogr 2:130-132

Little, E. L., R. O. Woodbury and F. H. Wadsworth. 1974. Trees of Puerto Rico and the Virgin Islands. Agricultural Handbook no. 449. U. S. Department of Agriculture, Forest Service, Washington, D. C. USA

McDowell, W. H. and A. Estrada-Pino. 1988. Rainfall at the LEF Field Station, 1964-1986. CEER-T-228. Center for Energy and Environment Research. Rio Piedras, Puerto Rico.

Nuñez- Farfán J., Dirzo R. 1988. Within-gap spatial heterogeneity and seedling performance in a Mexican tropical forest. Oikos 51:274-284

Opler P.A. 1974. Biology, ecology and host specificity of microlepidoptera associated with Quercus agrifolia (Fagaceae). University of California Press. Berkeley

Waide, R. B. and D. P. Reagan. 1996. The rainforest setting. Pages 1-16 in D. P. Reagan and R. B. Waide, editors. The food web of a tropical rainforest. The University of Chicago Press. Chicago, Illinois, USA.

You C. 1991. Population dynamics of Manilkara bidentata in the Luquillo Experimental Forest. Puerto Rico. Phd dissertation, University of Tennessee, Knoxville

Zimmerman J. K., Everham III E. M., Waide R. B., Lodge D. J., Taylor C. M., Brokaw N. V. L. 1994. Responses of tree species to hurricane winds in subtropical wet forest in Puerto Rico: implications for tree life histories. J Ecol 82:911-922

CROSS-REFERENCES (other data sets related to this one): LTERDBAS99: Herbivory of eight common species at El Verde from 1994 to 1996, LTERDB102: Leaf miners (Acrocercops sp.)larvae performance on young leaves of Manilkara bidentata, LTERDBAS103 : Effect of plant density and light availability on leaf damage in Manilkara bidentata

SAMPLE LOCATION:

STORAGE SITES: ITES Data Management DM-002, Drawer#?; Mitchell Aide Laboratory at Biology Departmen, Natural Science Faculty, University of Puerto Rico, NCN Building Of. 308.

INVESTIGATOR'S ASSIGNED KEYWORDS: herbivory, Manilkara bidentata, el verde, disturbance, Acrocercops sp, density, light

LEF LTER OFFICIAL KEYWORDS (See table): EL VERDE, TABONUCO, DISTURBANCE, HERBIVORY, PEER REVIEWED JOURNAL

PUBLICATIONS:
Angulo-Sandoval, P. and T. M. Aide. 2000. Effects of plant density and light availability on leaf damage in Manilkara bidentata (sapotaceae). Journal of Tropical Ecology.

Angulo-Sandoval, P. and T. M. Aide. 2000. Leaf phenology and leaf damage of saplings in the Luquillo Experimental Forest, Puerto Rico. Biotropica

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

FILING
___ "File" copy only : Data Management will only file an electronic copy of the data file and its documentation
X "Enter" data on-line : Data Management will be in charge of entering the data on computer files (Contact Eda C. Meléndez)

SITES DESCRIPTIONS: The study was conducted in the Luquillo Experimental Forest (LEF), which is part of the Caribbean National Forest in northeastern Puerto Rico (Waide and Reagan 1996). The study area is near the El Verde research station (350 m) on Northwest slope of the LEF. The forest is classified as subtropical wet forest and the dominant tree species are Dacryodes excelsa, Prestoea montana, Casearia arborea, Inga laurina, Manilkara bidentata, and Sloanea berteriana (Zimmerman et al. 1994). The average height of the forest canopy is 20 m and there are few emergent trees (Waide and Reagan 1996). Mean annual precipitation is 3460 mm (McDowell and Estrada-Pino 1988), and although January to April is the period of lowest precipitation, monthly means are usually greater than 100 mm/month (Brown et al. 1983) and evapotranspiration is lower than precipitation throughout the year (Waide and Reagan 1996). Mean monthly temperatures range between 21-25^oC. (Brown et al. 1983).

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude
Luquillo Experimental Forest (LEF)	180° 20' N	65° 49' W

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1	1	1	1
ABBREVIATION (as it appears on the data file)	APRIL_ADULTS-UPPER	MAY_ADULTS-UPPER	JUNE_ADULTS-UPPER	JULY_ADULTS-UPPER	AUGS_ADULTS-UPPER	SEP_ADULTS-UPPER
NAME OF VARIABLE	April measurement of adult upper branches percent of herbivory	May measurement of adult upper branches percent of herbivory	June measurement of adult upper branches percent of herbivory	July measurement of adult upper branches percent of herbivory	August measurement of adult upper branches percent of herbivory	September measurement of adult upper branches percent of herbivory
DEFINITION OF VARIABLE	Percent of herbivory of upper branches of adult trees in April 1995	Percent of herbivory of upper branches of adult trees in May 1995	Percent of herbivory of upper branches of adult trees in June 1995	Percent of herbivory of upper branches of adult trees in July 1995	Percent of herbivory of upper branches of adult trees in August 1995	Percent of herbivory of upper branches of adult trees in September 1995
UNIT
PRECISION	±.00001	±.00001	±.00001	±.00001	±.00001	±.00001
RANGE OR LIST OF VALUES	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100
DATA TYPE	integer	integer	integer	integer	integer	integer
MISSING DATA CODES	none	none	none	none	none	none

VARIABLES (ATTRIBUTES):

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1	1	1	1
ABBREVIATION (as it appears on the data file)	APRIL_ADULTS-LOWER	MAY_ADULTS-LOWER	JUNE_ADULTS-LOWER	JULY_ADULTS-LOWER	AUGS_ADULTS-LOWER	SEP_ADULTS-LOWER
NAME OF VARIABLE	April measurement of adult lower branches percent of herbivory	May measurement of adult lower branches percent of herbivory	June measurement of adult lower branches percent of herbivory	July measurement of adult lower branches percent of herbivory	August measurement of adult lower branches percent of herbivory	September measurement of adult lower branches percent of herbivory
DEFINITION OF VARIABLE	Percent of herbivory of lower branches of adult trees in April 1995	Percent of herbivory of lower branches of adult trees in May 1995	Percent of herbivory of lower branches of adult trees in June 1995	Percent of herbivory of lower branches of adult trees in July 1995	Percent of herbivory of lower branches of adult trees in August 1995	Percent of herbivory of lower branches of adult trees in September 1995
UNIT
PRECISION	±.00001	±.00001	±.00001	±.00001	±.00001	±.00001
RANGE OR LIST OF VALUES	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100
DATA TYPE	integer	integer	integer	integer	integer	integer
MISSING DATA CODES	none	none	none	none	none	none

VARIABLES (ATTRIBUTES):

VARIABLES (ATTRIBUTES):

VARIABLES (ATTRIBUTES):VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1	1	1	1	1
ABBREVIATION (as it appears on the data file)	OCT_JUVENILES	NOV_JUVENILES	DEC_JUVENILES	JAN_JUVENILES	FEB_JUVENILES	MAR_JUVENILES
NAME OF VARIABLE	October measurement of herbivory of juveniles trees	November measurement of herbivory of juveniles trees	December measurement of herbivory of juveniles trees	January measurement of herbivory of juveniles trees	February measurement of herbivory of juveniles trees	March measurement of herbivory of juveniles trees
DEFINITION OF VARIABLE	Percent of herbivory of juveniles trees measured in October 1995	Percent of herbivory of juveniles trees measured in November 1995	Percent of herbivory of juveniles trees measured in December 1995	Percent of herbivory of juveniles trees measured in January 1996	Percent of herbivory of juveniles trees measured in February 1996	Percent of herbivory of juveniles trees measured in March 1996
UNIT
PRECISION	±.00001	±.00001	±.00001	±.00001	±.00001	±.00001
RANGE OR LIST OF VALUES	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100	0 - 100
DATA TYPE	integer	integer	integer	integer	integer	integer
MISSING DATA CODES	none	none	none	none	none	none

COMPUTATIONAL METHODS:

Variable Name	Formula
All	% leaves = (total number of leaves produced in a year/number of leaves produced in a month)*100

FOR DATA MANAGER USE ONLY

DATE OF LAST REVIEW: May 1, 2008
DATE OF LAST ENTRY: October 1996
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED 9 Sep 1998
ENTERED: FILED 10 Sep 1998 (?)
ON-LINE not until published
REVIEWED BY RESEARCHER 9 Sep 1998
FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdb103.fm*
NAME OF DATA FILE: hbv9#9#.wb2
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 103
DOCUMENT TYPE: magnetic media
PRIORITY TO BE ENTERED: N/A

Rev. date of this form: 19 March 2002