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.

(Data, Abstract, Methods, Variable)

NOTES:

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

Jill Thompson jthompson@lternet.edu


DATA SET IDENTIFIER: 
Census of species, diameter and location at the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico

PROJECT TITLE: Luquillo Forest Dynamics Plot - Community Structure and Disturbance in a Tropical Forest.

PROJECT DESCRIPTION: The processes that determSine the plant species diversity and structure of tropical forest are still uncertain despite many years of investigation. A tropical forest characteristically has few common species and many rare species, with conspecifics often widely distributed throughout the forest. The potential for inter and intra-specific interactions are numerous, and it is difficult to determine which factors maintain species diversity or how rare species survive in the population. Factors that we believe contribute to tropical forest structure and composition include the physical environment and past history of the forest, species-specific physiological requirements for light, nutrients and water necessary for growth, survival and reproduction, and pathogens and herbivores. Despite the substantial amount of information available about these factors, we are still unable to accurately model the current composition of tropical forest or to predict its future response to human and natural disturbances.

The Luquillo Forest Dynamics Plot (LFDP), previously known as the Hurricane Recovery Plot (Zimmerman et. al. 1994) and the Luquillo long-term ecological research grid (Soil Survey 1995), is a 16-ha forest plot (SW corner 18° 20' N, 65°49' W) located near El Verde Field Station. The plot is 500 m N-S and 320 m E-W and is divided into 400 20 x 20 m quadrats, with each quadrat sub divided into 16 5 x 5 m sub-quadrats. The field station and LFDP are in the Luquillo Mountains of northeastern Puerto Rico, approximately 35 km southeast of San Juan. Information from the LFDP contributes to the efforts of the Center for Tropical Forest Science (CTFS, Smithsonian) network of large tropical forest plots in order to improve our understanding of tropical forest and to predict its future. Large plots (typically 50 ha) are required to cover local environmental variation, include sufficient numbers of individuals of both the common and rare species, and to determine plant spatial relationships. Population monitoring is required over many years to elucidate tree life histories, species interactions and population changes in order to determine the forest response to environmental changes and disturbance.

The LFDP is unique among the CTFS sites as it has a history of land use disturbance and also hurricane damage. These two disturbance types interact and influence the community dynamics and species composition in the LFDP. The Northern area (approximately two thirds of the plot) was disturbed by tree felling and farming until 1934 when the land was purchased by United States Department of Agriculture, Forest Service. The Southern third was not farmed and only suffered relatively light disturbance from selective logging. Aerial photographs taken in 1936 show differences in canopy cover caused by the patterns of land use history. Clear patterns in the distribution of some species reflect this land use history (Thompson et. al. in press). The distribution of species as a result of the land use history interacts with hurricane disturbance, as those species colonizing the northern part of the LFDP are more susceptible to hurricane damage (Zimmerman et. al. 1994). Major hurricanes struck the forest area of the LFDP in 1928 and 1932 and after a 66 year period with relatively little hurricane damage, the forest was struck by Hurricane Hugo in 1989 and Hurricane Georges in 1998, both hurricanes causing significant damage.

LFDP CENSUS HISTORY.

The LFDP was established in 1990 and the censuses are carried out in accordance with CTFS protocol (Condit 1998) with only minor variations. The first assessment of stems >= 10 cm D130  (diameter at breast height [DBH] of 130 cm from the ground) consisting of stems damaged by Hurricane Hugo (September 1989) was carried out from August 1990 to September 1991 (Everham 1996). The first complete census of all stems >=1 cm D130 lasted from August 1990 to September 1993. This first census was divided into three surveys with the first survey (August 1990 to February 1992) comprising all free standing (excluding lianas) woody stems >= 10 cm D130. The second survey (overlapping the third survey) consisted of checks on a small number of quadrats in which a few large stems >= 10 cm D130 were found that had been "missed" during the first survey. The third survey of woody stems >= 1 cm <10 cm D130 was carried out between April 1992 and September 1993. During Census 1 surveys 2 and 3 stems were found that were >=10 cm D130 and, therefore, were most likely to have been present in the forest at the time of Census 1 survey 1. In addition in Census 2 (November 1994 to October 1996), stems were found >=3 cm D130 (>=5 cm D130 for Cecropia schreberiana and Schefflera morototoni) which may have been missed in Census 1. In order to include these "missed" stems in the appropriate census and survey we calculated what diameter the stem would have been at the time the quadrat in which it was located was initially assessed. These "missed" stems were allocated to earlier censuses and census surveys based either upon the actual growth rate of that stem, if more than one measurement was available, or the median growthrate for that species. The median growthrate was calculated for two size classes of stems >=1, <10 cm, or >=10 to 30 cm D130. Using the most appropriate growthrate the diameter of the "missed" stem was extrapolated back in time to estimate the stem diameter at the correct survey time in Census 1. If the calculated diameter matched the size class for an earlier survey the stem was allocated to it with its estimated diameter. Information for stems >=10 cm D130 damaged during Hurricane Hugo was combined with data for stems >=10 cm D130, in census 1 survey 1 together with "missed" stems recorded in later surveys to reconstruct the forest as it was at the time of Hurricane Hugo. The reconstruction to represent the forest at the time of Hurricane Hugo did not include diameter extrapolations back to September 1989, but to the time at which the appropriate size class of stems were measured between August 1990 and September 1993. The palm Prestoea acuminata was allocated to earlier census surveys based upon the height of the point of measurement and additional observations. Further details on the procedures for allocating these "missed" stems to the appropriate census surveys can be found in the descriptions in the relevant data files. The last corrections to the Census 1 this data were made in May 2001.

In all censuses individual stems of the specified size were tagged, identified and measured for D130. On multiple stemmed plants, all stems were individually tagged and the group of stems representing an individual plant was recorded. In the first and second census stems >=10 cm D130 were mapped. Following CTFS protocol we are conducting the censuses at 5 year intervals. The second census (November 1994 to October 1996) consisted of only one survey with all stems >=1 cm D130 censused at the same time, although only stems >=10 cm D130 were mapped. The third census (funded by the Andrew Mellon Foundation) started in July 2000 and is expected to finish in April 2002. In this third census, in addition to mapping stems >=10 cm D130, we are also mapping the location of stems >=1 cm D130.

ACKNOWLEDGMENTS:

We are grateful for the work of many people who helped inventory the LFDP. In particular, technicians: R. DeLeon, J. Bithorn, M. Aponte, A.-L. Méndez, M. Estades, A. Estrada, S. Matta, plant taxonomist B. Boom, and data manager Eda Melendez. Many volunteers, too numerous to mention, were also a tremendous help with the census. We thank the United States Department of Agriculture and Natural Resources Conservation Service, Lincoln, Nebraska, USA for the soil survey. The International Institute of Tropical Forestry (IITF) gave us access to their historical records and timber cruise surveys, and we thank Dr. Frank Wadsworth and Octavio Jodan who helped interpret them. John Thomlinson helped prepare the digital maps of stem locations and the soil map. The aerial photographs were analyzed at The Harvard Forest, Harvard University.

LTER CORE AREAS: (Annotate all that apply)

Population Dynamics
Disturbance Patterns
Primary Productivity

LEF LTER 1 RESEARCH TOPIC: (Annotate all that apply)
Recovery After Disturbance
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 FileNo. Data File Identifier On-Line Filename Starting Date Periodicity of sample Period
1 LFDP census 1 species, diameter and location-Part1 LFDP_Census1-Part1.txt

July 30, 1990

once August 10, 1993
2 LFDP census 1 species, diameter and location-Part2

LFDP_Census1-Part2.txt

August 10, 1993 once August 20, 1993
3 LFDP census 2 species, diameter and location-Part1

LFDP_Census2-Part1.txt

July 6, 1995 once July 26, 1996
4 LFDP census 2 species, diameter and location-Part2

LFDP_Census2-Part2.txt

July 26, 1996 once August 09,1996
5 LFDP census 3 species, diameter and location-Part1

LFDP_Census3-Part1.txt

July 24, 2000 once January 11 , 2002
6 LFDP census 3 species, diameter and location-Part2

LFDP_Census3-Part2.txt

January 11, 2002 once April 11, 2002
7 LFDP census 4 species, diameter and location-Part1 LFDP_Census4-Part1.txt December 7, 2006 once September 20, 2006
8 LFDP census 4 species, diameter and location-Part2 LFDP_Census4-Part2.txt September 20, 2006 once

February 21, 2007

Note: If for some reason you have problems accessing and downloading tde data tdrough the forms, send us a message to emelendez@lternet.edu in which you give us a brief statement of tde purpose to use tde data.

RESEARCH LOCATION: Luquillo Forest Dynamics Plot (LFDP, southwest plot corner 18° 20' N, 65° 49' W), El Verde Research Area, Luquillo Experimental Forest, Caribbean National Forest, Puerto Rico

INVESTIGATORS

PRINCIPAL INVESTIGATORS E-MAIL address
Jess Zimmerman jzimmerman@lternet.edu

OTHER RESEARCHERS E-MAIL address
Jill Thompson jthompson@lternet.edu
Nicholas Brokaw nbrokaw@lternet.edu
Robert B. Waide

rwaide@lternet.edu
Wyn M. Everham III eeverham@fgcu.edu
D. Jean Lodge DJLodge@coqui.net
Charlotte M. Taylor  
Diana Garcia-Montiel dgarcia@ites.upr.edu
Marcheterre Fluet  

CONTACT PERSONS E-MAIL address Phone Number (Include area code)
Jess Zimmerman jzimmerman@lternet.edu (787)764-0000 (1-3721)
Jill Thompson jthompson@lternet.edu  

SOURCE OF FUNDING (SPONSOR): The LFDP was established with funds from a National Science Foundation (NSF) SGER grant, BSR-9015961 to the University of Puerto Rico (UPR). This work was also supported by LTER grants BSR-8811902 and BSR-8811764 from NSF to the Institute for Tropical Ecosystem Studies, UPR, and to IITF, as part of the Long-Term Ecological Research Program in the Luquillo Experimental Forest. The U.S. Forest Service (Dept. of Agriculture) and UPR gave additional support. Funds were also provided through grants RII-880291 and HRD-9353549 from NSF to UPR’s Center for Research Excellence in Science and Technology. Funding for current work on the LFDP comes from the Andrew W. Mellon Foundation.

DATA SET ABSTRACT: File LFDP_CENSUS1 contains data for the Census 1 (Survey 1,2,and 3) of the LFDP including the Tag number Species code, quadrat location and date and stem diameter D130 (diameter measured at 130 cm from the ground (DBH). It also contains the diameter as recorded for all stems in survey 1, 2 and 3. LFDP_CENSUS1a has the same structure as LFDP_census1. In LFDP_census1a file, however, the stem diameters have been calculated to allocate "missed" stems that were found in survey 2, 3 or Census 2 to either Census 1 survey 1 (stems >=10 cm D130) or Census 1 survey 3 (stems >=1, <10 cm D130).

We calculated the diameter the stem would have had, if it had been recorded at the same time the quadrat it was located in was assessed, in the appropriate survey for that stem size. To extrapolate the stem size back in time, we used the actual growth rate of that individual stem if more than one measurement was available. If only one diameter measurement was available we used the median growth rate for that species in the appropriate size class (median growthrate of stems <10 cm, or median for stems >=10, <30 cm D130). In our publications we will combine data sets LFDP_census1 and LFDP_census1a to make Census 1 and to reconstruct the forest for stems >= 10 cm D130 at the time of Hurricane Hugo.

We have divided the data into two separate files to ensure that when stem diameters are compared to future censuses the diameter data in LFDP_census1a is not used to calculate growth rates. The dates in LFDP_census1a show the date at which the real diameter was measured in survey 2 or 3 and not the time that the calculated diameter (Fdiam sur1/s2/s3) represents for the quadrat in which the stem was located. Blank in the date field in LFDP_census1a means that the tree was first measured in Census 2 and the diameter given (Fdiam sur1/s2/s3) was extrapolated back in time to Census 1. The last corrections to the Census 1 data were made in May 2001.

The National Science Foundation requires that data from projects it funds are posted on the web two years after any data set has been organized and “cleaned”. The data from each census of the LFDP will be updated at intervals, as each survey of the LFDP shows errors in the previous data collection. After posting on the web, researchers who are not part of the project are then welcome to use the data. Given the enormous amount of time, effort and resources required to manage the LFDP, obtain these data, and ensure data accuracy, LFDP Principal Investigators request that researchers intending to use this data comply with the requests below. Through complying with these requests we can ensure that the data are interpreted correctly, analyses are not repeated unnecessarily, beneficial collaboration between users is promoted and the Principal Investigators' investment in this project is protected.

Please comply with the following requests:

  • Submit to the LFDP PIs a short (1 page) description of how you intend to use the data;
  • Invite LFDP PIs to be co-authors on any publication that uses the data in a substantial way (some PIs may decline and other LFDP scientists may need to be included);
  • If the LFDP PIs are not co-authors, send the PIs a draft of any paper using LFDP data, so that the PIs may comment upon it;
  • In the methods section of any publication using LFDP data, describe that data as coming from the “Luquillo Forest Dynamics Plot, part of the Luquillo Experimental Forest Long-Term Ecological Research Program”;
  •   Acknowledge in any publication using LFDP data the “The Luquillo Experimental Forest Long-Term Ecological Research Program, supported by the U.S. National Science Foundation, the University of Puerto Rico, and the International Institute of Tropical Forestry”;  Supply the LFDP PIs with 10 reprints of any publication using LFDP data;
  • ·   Accept that the LFDP PIs can not guarantee that the LFDP data you intend to use has not already been submitted for publication or published.

    DATA SET METHODS: The LFDP censuses are carried out according to CTFS protocol (Condit 1998) with minor exceptions. All stems >= 1 cm D130  (diameter at 130 cm above the ground [DBH]) are measured for diameter, tagged, identified and mapped. Stems <5 cm diameter were measured with calipers and stems >= 5 cm were measured with diameter tape. There are three notable differences between this data set and the CTFS protocol. In addition we also recorded Heliconia carribea culms and tree fern Cyathea arborea and fern Nephelea portoricensis. A full protocol is available on request.

      Differences between LFDP and CTFS protocol.

      ·   The Census 1 data contained in these files is comprised of three surveys as noted in the dataset abstract and project description above.

      ·   Recording multiple stemmed plants and trees with sprouts. As this forest suffers hurricanes many trees do not die standing, before falling over, but are pushed over by wind and other trees during hurricanes. These trees then sprout and contribute significantly to the structure of the forest. In the LFDP one stem (usually the largest diameter) on a multiple stemmed plant is designated as the "main stem". This tag number always represents that individual plant even if the actual stem so numbered eventually dies. The stem with a main stem tag number is always recorded as alive if there are any sprouts or other stems living on the plant. All sprouts that arise along the whole length of a prone stem are individually tagged and measured and the corresponding number of the "main stem" that they are grow from, is put in the "main stem" field in the data set. The "main stem" system is also used for branches and sprouts that arise below 130 cm from the ground and attain a diameter of >= 1 cm D130. Counts of individuals must be distinguished from counts of stems in most analyses.

      ·   The third difference is that palms Prestoea acuminata are not always measured only at 130 cm from the ground see below on discussion for "palm height".

      ·   Heliconia sp. culms were included in Census 1 survey 3. Culms were counted in easily countable groups (it is not possible to distinguish individuals). Culms were counted it they reached 10 cm in height in a clump. The number of culms is recorded in "no culms sur3" field. Musaseae sp. ie plantains and bananas were not identified to species and were also counted as culms.

      · Tree ferns were included in the census as soon as it was possible to measure the diameter of the stem at 130 cm from the ground, without interference from the frond bases.

      · Tag number is a unique number to identify each individual stem (not individual tree). A negative tag number means there was an error in the census data and two stems were given the same number. These duplicates could not be given new tag numbers for a variety of reasons, so remain in the data as negative tag numbers to preserve the unique tag number requirement.

    Quadrat describes the position of each 20 x 20 m quadrat within the grid structure of the 16 ha plot (see details of variables). Each 20 m x 20 m quadrat is subdivided into 16 5 m x 5 m subquadrats and each stem is located at the subquadrat scale by the subquadrat number.

    NEWSPP is the species code after the stem was re-identified during the second census. This code represents the first three letters of the genus and first three for the species in most cases. Exceptions occur when species have changed their names, or when confusion between species may arise using this 6 letter code. Full species names are listed in another file (see other data sets below)

    Palm height sur1/s2/s3, is the height at which the diameter on the Prestoea acuminata previously called Prestoea montana (PREMON). Palms do not usually increase in diameter with time and in order to incorporate this important component of this forest the palms are measured in a slightly different manner than tree stems. When the newest frond of a palm arises at a height of 130 cm from the ground the palm is entered into the census and the diameter is measured between the leaf scars on the "bole" of the last two fronds that have fallen off. Measuring above this would involve measuring around fronds that would fall off at a later date. The height at which this diameter measurement was taken was recorded as "palm height". Older palms that have a bole that extends above 130 cm from the ground always have their diameter measured at this height. Errors in the data recording meant that for many palms in Census 1 survey 1 no palm heights were recorded. Where this is the case I have inserted -130 to indicate that the diameter measurement was most likely recorded at 130 cm from the ground. For some palms I used supplementary data to allocate palms to the appropriate survey when the palm height information was not recorded. These codes -100, and -101 do not indicate any palm height measurement.

    REFERENCES:

    Condit, R. 1998. Tropical Forest census Plots. Springer, Berlin

    Everham, E. M. III 1996. Hurricane disturbance and recovery: An empirical and simulation study of vegetation dynamics in the Luquillo Experimental Forest. PhD. State University of New York.

    Soil Survey Staff. 1995. Order 1 Soil Survey of the Luquillo Long-Term Ecological Research Grid, Puerto Rico. United States Department of Agriculture, Natural Resources Conservation Service, Lincoln, Nebraska, USA.

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

    CROSS-REFERENCES (other data sets related to this one): LTERDBAS46: Elevation at grid points on the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico; LTERDB47: Physical environment of the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico, LTERDB57: Tree damage by Hurricane Hugo at the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico, LTERDB60: Tree Map for Census at the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico; LTERDB62: Canopy height profile starting 1992, 1994 and 1996 of the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico; LTERDB118: Species names and codes of the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico; LTERDB119: Census of species, diameter and location at the Luquillo Forest Dynamics Plot (LFDP), Puerto Rico; LTERDB129 : Temperature and humidity in the LFDP (40 points)

    SAMPLE LOCATION: N/A

    STORAGE SITES (of data files): Paper and computer files at ITES; Computer files at El Verde Field Station

    INVESTIGATOR'S ASSIGNED KEYWORDS: 
    Luquillo Forest Dynamics Plot, LFDP, Hurricane Recovery Plot, plant community composition, plant diversity,  Luquillo Experimental Forest, El Verde Field Station, Puerto Rico

    LEF LTER OFFICIAL KEYWORDS  (See table): EL VERDE, LFDP (EV Big Grid), MOIST, TABONUCO, COMMUNITY COMPOSITION, DISTURBANCE, HUMAN, HURRICANE, ENVIRONMENTAL VARIABLES, POPULATION DYNAMICS , PRIMARY PRODUCTION, TREE GROWTH, HIGHER PLANTS, FERNS, HERBS, PALMS, SHRUBS, TREES , PEER REVIEWED JOURNAL

    PUBLICATIONS:
    Brokaw, N., Fraver, S., Grear, J.S., Thompson, J., Zimmerman, J.K., Waide, R. B., Everham, E.M., Hubbell, S.P., Condit, R. and Foster, R.B., (2000). Disturbance and Canopy structure in two tropical forests. In press. R. Condit, and J. Lafrakie (eds) Tropical forest diversity and dynamism: results from a network of large plots. Smithsonian Institution.

    Brokaw, N. and Thompson. J. (2000). The H for DBH. Forest Ecology and Management 129, 89-91.

    García-Montiel, D. C. (In press). La presencia humana en los bosques neotropicales húmedos. In M. Guariguata and G. Kattan, editors. Ecología de Bosque Lluvioso Neotropical. Editorial Agroamérica, San José, Costa Rica.

    Thompson, J., N. Brokaw, J. K. Zimmerman, R. B. Waide, E. M. Everham, III, D. J. Lodge, C. M. Taylor, D. García-Montiel, and M. Fluet. (In press). Land use history, environment, and tree composition in a tropical forest. Ecological Applications.

    Thompson, J., Brokaw, N., Zimmerman, J.K., Waide, R.B., Everham, E.M.. and Schaefer, D.A. (2000). The Luquillo forest dynamics plot. (In press). R. Condit, and J. Lafrakie (eds) Tropical forest diversity and dynamism: results from a network of large plots. Smithsonian Institution.

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

    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

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

    SITES DESCRIPTION: The LFDP is within the Luquillo Experimental Forest (LEF, established in 1956) which is coterminous with the Caribbean National Forest and covers 11,330-ha of the Luquillo mountains (Brown et al. 1983). There are four different forest types within the LEF including tabonuco, colorado, palm-brake, and dwarf forest. These forest types are associated with different soil types and are roughly stratified by elevation (Brown et al. 1983). The LFDP lies within the tabonuco forest that is named after a dominant tree, Dacryodes excelsa Vahl (Burseraceae). Tabonuco forest develops best on low, protected, well-drained ridges below 600 m a.s.l. Mean canopy height in tabonuco forest is about 20 m, with tallest trees to c. 35m. Few trees in the LFDP exceed 1 m D130. The forest in Puerto Rico is subject to hurricane damage and canopy height is lower, and canopy structure is broken, in the years after hurricanes.

    CLIMATE

    The climate is classified as tropical montane in Walsh’s (1996) tropical climate system, and as subtropical wet in the Holdridge life zone system (Ewel and Whitmore 1973). Annual rainfall at El Verde averages just over 3500 mm yr-1 (1975-1999). On average there is no month with <200 mm of rain, although a drier season occurs from January through April. The highest rainfall recorded at El Verde between 1975 and 2001 (370 mm in less than 12 hours) fell on 17 April 1997. There are also severe droughts, such as in 1994, when less than 70% of the average annual rain fell, and many small streams in the forest stopped flowing entirely for two months. Daily average maximum air temperature is 25.2°C, minimum is 20.5°C, and average is 22.8°C (Brown et al. 1983, and also see weather data on this web site). Severe hurricanes struck the LFDP forest area in 1928, 1932, 1989 and 1998.

    Geographical positional system (GPS) Coordinates for each location:
    location latitude longitude
    South West Corner of plot 18° 19' 26" North 65° 49' 3" West

    VARIABLE (ATTRIBUTES) :
    FILE NAME OR #ABOVE(all in which the variable appears) 1, 2, 3, 4 1, 2, 3, 4 1, 2, 3, 4 1, 2, 3, 4 1,2, 3, 4
    ABBREVIATION(as it appears on the data file) tag stemtag spcode quadrat gx
    NAME OF VARIABLE Tag Number Stem Tag Number Species code Quadrat code number GlobalX coordinate
    DEFINITION OF VARIABLE Unique number for each main stem in the entire LFDP.The main stem tag number is the number for an individual plant. Numbers in this field show that the stem with a stemtag number, in the same row of data is attached to the stem with this main stem number.No data is missing in this field. Unique number for each stem in the entire LFDP.No data is missing inthis field A 6 letter code for the species name for this individual. First three letters are the first three letter of the genus and the second three letters the first three letters of the species name. Variations to this rule are possible. See species list file LFDP_species. The species identifications include corrections made after census 2. r.No data is missing in this field. Code represents the 20 x 20 m quadrat based upon its position in the rows and columns of the 16 ha grid. The first 2 digits form the column number counting quadrats from West to East and the second two digits form the row number counting quadrats South to North. Leading zeros are not displayed so quadrats in columns 1-9 have only 3 digits The location of the stem relative to the Southwest corner of the LFDP. Distance in meters East.Precision is+ or - 0.5 m in the field (digitizer gives .01 m).Blank means no data recorded.
    UNIT         meter
    PRECISION         0.5
    RANGE OR LIST OF VALUES       0101 = first quadrat in southwest corner, 0102, 0103, ...., 0116, 0201, ...2525 = last quadrat in North East corner 0 - 320
    DATA TYPE integer integer alphanumeric alphanumeric numeric
    MISSING DATA CODES          

    VARIABLES (ATTRIBUTES):
    File Name or # above (all in which the variable appears) 1,2, 3, 4 1,2, 3, 4 1, 2, 3, 4 1,2, 3, 4 1, 2, 3, 4
    Abbreviation (as it appears on the data file) gy dbh codes hom date
    NAME OF VARIABLE GlobalY coordinate diameter Alive or Dead stem or Not Found coding   Date stem diameter recorded in census
    DEFINITION OFVARIABLE The location of the stem relative to the Southwest corner of the LFDP. Distance in meters North.Precision is+ or - 0.5 m in the field (digitizer gives .01 m).Blank means no data recorded.u diameter measured  at 1.3 m from the ground. All A as only live stems are included in census 2. If the stem is the main stem, the individual stem could in fact be dead but the main stem counts as alive if there are live sprouts attached. No data is missing in this column. height of measurement (pom = point of measurement).   In the first census this was not recorded so very few are in the data.  Some in the data are pom that were recorded in 1995 using paint marks on the trees that were still on the stem from 1990. at 1.3 m from the ground and can be sued to compare basal area with other plots and this file has the dbh starting points for the measurements from 1995 to 2000. Date (in mm/dd/yyyy)when the stem was measured. Accuracy of this date varies from+ or - for 2 weeks. Dates vary from 6/27/90 to 9/29/93 with many dates not used, for census 1;10/26/94 to 6/12/97 for census 2; 7/24/2000 to 8/29/2002 for census 3; 2005 to 5/272008 for census 4. A blank value means data is missing. Only in file of Census 1 a blank means stem first recorded in Census 2
    UNIT meter millimiter   meter  
    PRECISION 0.5        
    RANGE OR LIST OF VALUES 0 - 500   A = stem alive, AB = alive plant whoes main stem is broken below 1.3 m, B = stem broken below or dead at 1.3 m the normal poin, BUT = tree has buttresses - might explain pom, D = dead stem, DTree = dead tree, L = stem leaning atmore than 45 degrees from vertical, NDI = new diameter incorrect-diameter in this file poss, NDR = no diameter recorded census ctfs b160 or 1 (luq 1, NF = not found, NPD = new point of measurement different to previous, NPI =, NR = stem not recorded, NR1 = not recorded in first census 0 - ctfs census 0 luq, NR2 = diameter not recorded in second census ie ctfs cen, ODI = old diameter - from first census ctfs 0 liq 1 (199, P = stem lying on the ground, POM = point of measurement problem different to last tim, S = stem standing upright, SA = small alive, tagged stem <1 cm diameter. Tag left, SP = sprout >= 1 cm diamter at 1.3 m from on multiple s, SPD = sprout dead at 1.3 m of broken below 1.3 m from th, ST =, T = tree tipped up, UM = stem unmeasureable because of position or location, V = pom different because of vine attached to stem or, main = main stem    
    DATA TYPE numeric numeric alphanumeric numeric datetime
    MISSINGDATA CODES          

    COMPUTATIONAL METHODS:
    Variable Name Formula
    Calculation of "Fixed" diameter of stems given in LFDP_CENSUS1a.txt

    1) When two stem diameters are known

    (Diam at Time2 – Diam at Time1)/ (Time2 – Time1) = Growthrate;

    Growthrate * (Time1 – Time0 of unknown Diam) = Growth from Time0 of unknown Diam;

    Unknown Diam at Time0 = Diameter at Time 1 -Growth from Time0 of unknown diameter.

    2) When only one diameter is known, substitute the median growthrate for the same species in 1) above. Use the median for the appropriate size class of stems, either >=1,<10 cm or >=10, <=30 cm.
    3) If two diameters are known for time 1 and time 2 and the second is smaller than the first i.e. a negative growthrate. Substitute the smallest of the two diameters fo


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    Rev. date of this form: 15 July 2001