DATA SET IDENTIFIER: Herbivory of eight common species at El Verde from 1994 to 1996

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):

Data File No.	Data File Identifier	On-Line Filename	Starting Date	Periodicity of sample	End Period
1	Herbivory Nov 1994 to Oct 1995	hbv9495.txt	November 1994	monthly	October 1996
2	Herbivory Nov 1995 to Oct 1996	hbv9596.txt	November 1994	monthly	September 1996

RESEARCH LOCATION: Several paths along and across the 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: In seasonal and aseasonal tropical forests, leaf production is often highly synchronous, concentrating herbivore resources in only a few months. As a result levels of herbivory on young leaves can vary throughout the year. To determine the importance of food availability on herbivory, leaf phenology and leaf damage were studied in an aseasonal forest, Luquillo Experimental Forest (LEF) in Puerto Rico. Leaf production was associated with an increase in light availability but leaf damage was relatively constant throughout the year. Leaf phenology and leaf damage was compared between LEF and a seasonal forest, Barro Colorado Island (BCI) Panamá. In BCI leaf production was associated with increases in water availability and leaf damage was significantly higher on leaves produced after the peak in leaf production. Leaf damage was significantly lower in LEF in comparison with BCI. Differences in the trophic structure between the two forests may explain the differences in levels of leaf damage. The density of frogs and lizards in LEF was approximately an order of magnitude greater than in BCI and these predators may limit the populations of herbivores and reduce leaf damage levels.

DATA SET METHODS: Leaf phenology and leaf damage were measured on plants (1-2 m in height) in the understory. Plants were located in plots along La Prieta, upper Sonadora and Ox cart trails. Two shrubs, Palicourea riparia (Rubiaceae) and Piper glabrecens (Piperaceae) and six tree species, Casearia arborea (Flacourtiaceae), Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Manilkara bidentata (Sapotaceae), Sloanea berteriana (Elaeocarpaceae) and Tabebuia heterophylla (Bignoneaceae) were studied. These species were chosen because they are among the most common species in at this site (Zimmerman et al. 1994). There have been few studies on the herbivore community of LEF, but Schowalter (1994) collected the major invertebrates associated with five common tree species and found that Lepidoptera, Coleoptera and Homoptera (cicadellids principally) were the most abundant herbivores, that are the principal herbivores in different type of forest (Duckett, pers. comm.).  In addition different species of walking sticks (Phasmida) are also important herbivores in LEF (Garrison & Willig 1996).

LEAF PHENOLOGY AND LEAF DAMAGE CENSUSES. --The study was conducted from November 1994 to October 1995 (year one) and from November 1995 to October 1996 (year two). Twenty individuals of each species were marked. All individuals were located in the understory. Each month, all new, full expanded leaves were counted and a maximum of ten leaves per plant was marked with plastic telephone wire. One month later, leaf area and area damaged were measured for all marked leaves using a plastic grid. Although this method may overestimate consumption by herbivores and underestimate the effect on leaf area (Coleman & Leonard 1995), there are few alternatives for determining multispecies patterns of leaf damage in tropical forest. In addition, the leaf production and leaf damage data were compared with data from BCI (Aide 1993) which were obtained using the same methodology.

ANALYSIS. --Leaves produced within a month by a single individual were considered independent events (leaf cohorts). For each individual, the monthly proportion of annual leaf production was calculated. For estimating the annual pattern of leaf production for the species, average leaf production of the twenty individuals was calculated for every month. Patterns of monthly leaf production for the eight species was calculated by averaging the means of each species. Patterns of leaf phenology were compared between years using a Kolmogorov-Smirnov test (Ott 1993). Cross correlations were performed to determine if rainfall, light intensity or day length were important cues for leaf production (Statistix 1996). A maximum lag time of two months was used for this analysis.

Monthly percent leaf damage was calculated for each leaf cohort. Total damaged area on the marked leaves was divided by the total potential leaf area. If a leaf was missing, the average size of the remaining leaves were calculated and the area was added to the total damaged area and to the total potential leaf area. All species showed a peak in leaf production during May - June and percent leaf damage was compared between the cohorts produced during the month of peak leaf production and the cohorts produced during the remaining months. The same comparison was made by combining data from all species. Percent leaf damage was compared between years using the Mann-Whitney U test.

Patterns of leaf production and leaf damage were compared between LEF and data obtained from BCI (32 species; 21 families) in 1987 (Aide 1993). Leaf phenology was compared using the Kolmogorov-Smirnov test. The Mann-Whitney U test was used for comparing leaf damage. Because all LEF species had synchronous leaf production, a second comparison of leaf damage was made only with the synchronous species from BCI (10 spp.).

REFERENCES:
Aide, T.M. 1991. Synchronous leaf production and herbivory in juveniles of Gustavia superba. Oecologia 88: 511-514.

Aide, T.M. 1993. Patterns of leaf production and herbivory in a tropical understory community. Ecology 74: 455-466.

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.

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.

Reagan, D. P., G. R., Camilo and R. B. Waide. 1996. The community food web: Major properties and patterns of organization. Pages 461-511 in D. P. Regan and R. B. Waide, editors. The food web of a tropical rainforest. The University of Chicago Press. Chicago, Illinois, USA.

Schowalter, T.D. 1994. Invertebrate community structure and herbivory in a tropical rain forest canopy in Puerto Rico following Hurricane Hugo. Biotropica 26: 312-319.

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.

SAMPLE LOCATION:

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

INVESTIGATOR'S ASSIGNED KEYWORDS: herbivory, community, el verde, disturbance

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. Leaf phenology and leaf damage of saplings in the Luquillo Experimental Forest, Puerto Rico. Biotropica (in press)

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 (180^o 20' N, 65^o 49' W) (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°C. (Brown et al. 1983).

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude
El Verde Study Area (La Prieta, upper Sonadora and Ox cart trails)

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1,2	1,2	1,2	1,2
ABBREVIATION (as it appears on the data file)	SPECIES	NUMBER	MONTH	YEAR
NAME OF VARIABLE	Species code	Tag number of the plant measured	Month when  measured	Year when measured
DEFINITION OF VARIABLE	Six letters code (first 3 are the first 3 letters of the genus, last 3 are the first 3 of the species)	Tag number attached to the plant for identification purposes for this project. Twenty individuals were chosen for each species	Month in which the measurements were taken	Year of measurement
UNIT	none	none	none	none
PRECISION	N/A	N/A	N/A	N/A
RANGE OR LIST OF VALUES	CASARB = Casearea arborea DACEXC = Dacryodes excelsa MANBID = Manilkara bidentata PALRIP = Palicourea riparia PIPGLA = Piper glabrecens GUAGUI = Guarea guidonea SLOBER = Sloanea berteriana TABHET = Tabebuia heterophilla	1 - 20 (for each species)	12 months	1994 - 1995
DATA TYPE	alphanumeric	integer	alphabetic	integer
MISSING DATA CODES	none	none	none	none

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1,2	1,2	1,2	1,2
ABBREVIATION (as it appears on the data file)	LEAVES	AREA	HBV	%HBV
NAME OF VARIABLE	Number of leaves  produced	Total area of leaves produced	Total area of leaves  removed	Percent of area of  leaves removed
DEFINITION OF VARIABLE	Total number of leaves (maximum of ten) produced by an individual in a given month	Total area of leaves (maximum of ten) produced by an individual in a given month	Total area of leaves removed by insects for an individual in a given month	Percent of area of leaves removed by insects for an individual in a given month
UNIT	none	cm2	cm2	percent
PRECISION	N/A	±.1	±.1	±.00001
RANGE OR LIST OF VALUES	1 - 10	4 - 1650	0 - 100	0 - 100
DATA TYPE	integer	real	real	percent
MISSING DATA CODES	none	none

COMPUTATIONAL METHODS:

Variable Name	Formula
(HBV/AREA) * 100  i.e. (seventh column/sixth column X 100)

DATE OF LAST REVIEW: May 15, 2006
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: lterdb99.fm*
NAME OF DATA FILE: hbv9#9#.wb2
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 99
DOCUMENT TYPE: magnetic media
PRIORITY TO BE ENTERED: N/A

Rev. date of this form: 18 March 2002