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.

DATA SET IDENTIFIER: Elevation at grid points on 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 determine 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 D₁₃₀was 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 D₁₃₀for 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 D₁₃₀were 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)

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	Quadrats topography column format	LFDPElevation-columnsformat.txt	June 15, 1990	once	January 30, 1992
2	Quadrats topography grid format	LFDPElevation-gridformat.txt	June 15, 1990	once	January 30, 1992

Notes: Last revision and update of data files: April 23, 2002. If for some reason you have problems accessing and downloading the data through the forms, send us a message to emelendez@lternet.edu in which you give us a brief statement of the purpose to use the data.

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

INVESTIGATORS:

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: This file contains data that describe the physical and environmental attributes of the LFDP. The attributes include elevation, topography type, and percentage slope. All data are given for the 20 m by 20 m quadrat scale. Information on soils are taken form an interpolation of the soil map produced by the Natural Resources Conservation Service, US Department of Agriculture (Soil Survey 1995). Other information from the elevation of each of the corner posts defining the quadrats.

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 Principle 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: Plot number, quadrat, column and row, describe the position of each 20 x 20 m quadrat within the grid structure of the 16 ha plot. The quadrat naming convention is described in the variable list and is the same as in Condit (1998). Xm and Ym are the distance east (X) and north (Y) respectively measured in meters from the southwest corner of the 16 ha plot to the southwest corner of each quadrat.

Elevation is based upon the plot surveyors data and was provided by them. The values for elevation, aspect and slope of each quadrat were calculated using a program Aspect13.for written by Win Everham (Everham 1996) and Neil Pederson. Elevation of each quadrat was based on the average elevation of the 4 corner posts around each 20 x 20 m quadrat. Aspect values are a numerical code representing direction are also based upon the elevations and relative position of the 4 quadrat corner posts on the topographic map generated by the elevation data (not ground truthed). Slope represents percent slope for the quadrat based upon the corner posts of each quadrat. Note the two different percent slopes. One "Ss%slope" is based upon the soil survey data and "Slope" is based upon the elevation of the corner pots.

REFERENCES: Brown, S. , A. E. Lugo, S. Silander, and L. Liegel. 1983. Research history and opportunities in the Luquillo Experimental Forest. USDA Forest Service General Technical Report SO-44, Southern Forest Experiment Station, New Orleans, Louisiana, USA.

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.

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. , Rear, J.S. , Thompson, J. , Zimmerman, J.K. , Waide, R. B. , Everham, E.M. , Hubbell, S.P. , Condit, R. and Foster, R.B. In press. Disturbance and Canopy structure in two tropical forests. In 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. Garc&icute;a-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. In press. The Luquillo forest dynamics plot. In 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 DBH. 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 25.2C, 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.

LFDP TOPOGRAPHY AND SOIL.

Topography on the LFDP has northwest-running drainages producing steep northeast and southwest-facing slopes, with an elevation across the plot which ranges from 333 to 428 m asl. The mean slope of the plot is 17% but ranges from 3 to 60%. Soils were formed in residual volcanic ash that fell in the ocean to form volcaniclastic sandstones and siltstones, which were subsequently uplifted (F. Scatena pers. comm. ). Soils are dominated by old, deeply weathered kaolinitic Oxisols (Zarzal) and Ultisols (Cristal), and young, less-developed Entisols (Coloso and Fluvaquents) and Inceptisols (Preito) in stream channels. Zarzal, Cristal and Prieto are deep clay soils, while Coloso and Fluvequents are formed from alluvium in the stream channels (Soil Survey Staff 1995).

Geographical positional system (GPS) Coordinates for each location:

location	latitude	longitude
South West Corner of plot	18° 19’ 26' North	65° 49’ 3' West

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	1	1
ABBREVIATION (as it appears on the data file)	Quadrat	AverageElevation
NAME OF VARIABLE	control point	Average elevation
DEFINITION OF VARIABLE	Identification number used by the surveyor's for the 20 m by 20 m grid points on the LFDP grid. Control points are counted from the South West corner control point number 1 to control point at the South East Corner number 17. Proceeding North to the West end of the second row and continuing east from control point 18 to 34 etc.	Average elevation of the each of the grid points on the LFDP entered in one record per each grid point. There are 17 grid points East to West (defining 16 20 x 20 m quadrats) and 26 grid points South to North (defining 25 20 m x 20 m quadrats)
UNIT		meter
PRECISION		0.1
RANGE OR LIST OF VALUES	1= (1 ,1); 2= (1 ,2); 3= (1 ,3); 4= (1 ,4); 5= (1 ,5); 6= (1 ,6); 7= (1 ,7); 8= (1 ,8); 9= (1 ,9); 10= (1 ,10); 11= (1 ,11); 12= (1 ,12); 13= (1 ,13); 14= (1 ,14); 15= (1 ,15); 16= (1 ,16); 17= (1 ,17); 18= (2 ,1); 19= (2 ,2); 20= (2 ,3); 21= (2 ,4); 22= (2 ,5); 23= (2 ,6); 24= (2 ,7); 25= (2 ,8); 26= (2 ,9); 27= (2 ,10); 28= (2 ,11); 29= (2 ,12); 30= (2 ,13); 31= (2 ,14); 32= (2 ,15); 33= (2 ,16); 34= (2 ,17); 35= (3 ,1); 36= (3 ,2); 37= (3 ,3); 38= (3 ,4); 39= (3 ,5); 40= (3 ,6); 41= (3 ,7); 42= (3 ,8); 43= (3 ,9); 44= (3 ,10); 45= (3 ,11); 46= (3 ,12); 47= (3 ,13); 48= (3 ,14); 49= (3 ,15); 50= (3 ,16); 51= (3 ,17); 52= (4 ,1); 53= (4 ,2); 54= (4 ,3); 55= (4 ,4); 56= (4 ,5); 57= (4 ,6); 58= (4 ,7); 59= (4 ,8); 60= (4 ,9); 61= (4 ,10); 62= (4 ,11); 63= (4 ,12); 64= (4 ,13); 65= (4 ,14); 66= (4 ,15); 67= (4 ,16); 68= (4 ,17); 69= (5 ,1); 70= (5 ,2); 71= (5 ,3); 72= (5 ,4); 73= (5 ,5); 74= (5 ,6); 75= (5 ,7); 76= (5 ,8); 77= (5 ,9); 78= (5 ,10); 79= (5 ,11); 80= (5 ,12); 81= (5 ,13); 82= (5 ,14); 83= (5 ,15); 84= (5 ,16); 85= (5 ,17); 86= (6 ,1); 87= (6 ,2); 88= (6 ,3); 89= (6 ,4); 90= (6 ,5); 91= (6 ,6); 92= (6 ,7); 93= (6 ,8); 94= (6 ,9); 95= (6 ,10); 96= (6 ,11); 97= (6 ,12); 98= (6 ,13); 99= (6 ,14); 100= (6 ,15); 101= (6 ,16); 102= (6 ,17); 103= (7 ,1); 104= (7 ,2); 105= (7 ,3); 106= (7 ,4); 107= (7 ,5); 108= (7 ,6); 109= (7 ,7); 110= (7 ,8); 111= (7 ,9); 112= (7 ,10); 113= (7 ,11); 114= (7 ,12); 115= (7 ,13); 116= (7 ,14); 117= (7 ,15); 118= (7 ,16); 119= (7 ,17); 120= (8 ,1); 121= (8 ,2); 122= (8 ,3); 123= (8 ,4); 124= (8 ,5); 125= (8 ,6); 126= (8 ,7); 127= (8 ,8); 128= (8 ,9); 129= (8 ,10); 130= (8 ,11); 131= (8 ,12); 132= (8 ,13); 133= (8 ,14); 134= (8 ,15); 135= (8 ,16); 136= (8 ,17); 137= (9 ,1); 138= (9 ,2); 139= (9 ,3); 140= (9 ,4); 141= (9 ,5); 142= (9 ,6); 143= (9 ,7); 144= (9 ,8); 145= (9 ,9); 146= (9 ,10); 147= (9 ,11); 148= (9 ,12); 149= (9 ,13); 150= (9 ,14); 151= (9 ,15); 152= (9 ,16); 153= (9 ,17); 154= (10 ,1); 155= (10 ,2); 156= (10 ,3); 157= (10 ,4); 158= (10 ,5); 159= (10 ,6); 160= (10 ,7); 161= (10 ,8); 162= (10 ,9); 163= (10 ,10); 164= (10 ,11); 165= (10 ,12); 166= (10 ,13); 167= (10 ,14); 168= (10 ,15); 169= (10 ,16); 170= (10 ,17); 171= (11 ,1); 172= (11 ,2); 173= (11 ,3); 174= (11 ,4); 175= (11 ,5); 176= (11 ,6); 177= (11 ,7); 178= (11 ,8); 179= (11 ,9); 180= (11 ,10); 181= (11 ,11); 182= (11 ,12); 183= (11 ,13); 184= (11 ,14); 185= (11 ,15); 186= (11 ,16); 187= (11 ,17); 188= (12 ,1); 189= (12 ,2); 190= (12 ,3); 191= (12 ,4); 192= (12 ,5); 193= (12 ,6); 194= (12 ,7); 195= (12 ,8); 196= (12 ,9); 197= (12 ,10); 198= (12 ,11); 199= (12 ,12); 200= (12 ,13); 201= (12 ,14); 202= (12 ,15); 203= (12 ,16); 204= (12 ,17); 205= (13 ,1); 206= (13 ,2); 207= (13 ,3); 208= (13 ,4); 209= (13 ,5); 210= (13 ,6); 211= (13 ,7); 212= (13 ,8); 213= (13 ,9); 214= (13 ,10); 215= (13 ,11); 216= (13 ,12); 217= (13 ,13); 218= (13 ,14); 219= (13 ,15); 220= (13 ,16); 221= (13 ,17); 222= (14 ,1); 223= (14 ,2); 224= (14 ,3); 225= (14 ,4); 226= (14 ,5); 227= (14 ,6); 228= (14 ,7); 229= (14 ,8); 230= (14 ,9); 231= (14 ,10); 232= (14 ,11); 233= (14 ,12); 234= (14 ,13); 235= (14 ,14); 236= (14 ,15); 237= (14 ,16); 238= (14 ,17); 239= (15 ,1); 240= (15 ,2); 241= (15 ,3); 242= (15 ,4); 243= (15 ,5); 244= (15 ,6); 245= (15 ,7); 246= (15 ,8); 247= (15 ,9); 248= (15 ,10); 249= (15 ,11); 250= (15 ,12); 251= (15 ,13); 252= (15 ,14); 253= (15 ,15); 254= (15 ,16); 255= (15 ,17); 256= (16 ,1); 257= (16 ,2); 258= (16 ,3); 259= (16 ,4); 260= (16 ,5); 261= (16 ,6); 262= (16 ,7); 263= (16 ,8); 264= (16 ,9); 265= (16 ,10); 266= (16 ,11); 267= (16 ,12); 268= (16 ,13); 269= (16 ,14); 270= (16 ,15); 271= (16 ,16); 272= (16 ,17); 273= (17 ,1); 274= (17 ,2); 275= (17 ,3); 276= (17 ,4); 277= (17 ,5); 278= (17 ,6); 279= (17 ,7); 280= (17 ,8); 281= (17 ,9); 282= (17 ,10); 283= (17 ,11); 284= (17 ,12); 285= (17 ,13); 286= (17 ,14); 287= (17 ,15); 288= (17 ,16); 289= (17 ,17); 290= (18 ,1); 291= (18 ,2); 292= (18 ,3); 293= (18 ,4); 294= (18 ,5); 295= (18 ,6); 296= (18 ,7); 297= (18 ,8); 298= (18 ,9); 299= (18 ,10); 300= (18 ,11); 301= (18 ,12); 302= (18 ,13); 303= (18 ,14); 304= (18 ,15); 305= (18 ,16); 306= (18 ,17); 307= (19 ,1); 308= (19 ,2); 309= (19 ,3); 310= (19 ,4); 311= (19 ,5); 312= (19 ,6); 313= (19 ,7); 314= (19 ,8); 315= (19 ,9); 316= (19 ,10); 317= (19 ,11); 318= (19 ,12); 319= (19 ,13); 320= (19 ,14); 321= (19 ,15); 322= (19 ,16); 323= (19 ,17); 324= (20 ,1); 325= (20 ,2); 326= (20 ,3); 327= (20 ,4); 328= (20 ,5); 329= (20 ,6); 330= (20 ,7); 331= (20 ,8); 332= (20 ,9); 333= (20 ,10); 334= (20 ,11); 335= (20 ,12); 336= (20 ,13); 337= (20 ,14); 338= (20 ,15); 339= (20 ,16); 340= (20 ,17); 341= (21 ,1); 342= (21 ,2); 343= (21 ,3); 344= (21 ,4); 345= (21 ,5); 346= (21 ,6); 347= (21 ,7); 348= (21 ,8); 349= (21 ,9); 350= (21 ,10); 351= (21 ,11); 352= (21 ,12); 353= (21 ,13); 354= (21 ,14); 355= (21 ,15); 356= (21 ,16); 357= (21 ,17); 358= (22 ,1); 359= (22 ,2); 360= (22 ,3); 361= (22 ,4); 362= (22 ,5); 363= (22 ,6); 364= (22 ,7); 365= (22 ,8); 366= (22 ,9); 367= (22 ,10); 368= (22 ,11); 369= (22 ,12); 370= (22 ,13); 371= (22 ,14); 372= (22 ,15); 373= (22 ,16); 374= (22 ,17); 375= (23 ,1); 376= (23 ,2); 377= (23 ,3); 378= (23 ,4); 379= (23 ,5); 380= (23 ,6); 381= (23 ,7); 382= (23 ,8); 383= (23 ,9); 384= (23 ,10); 385= (23 ,11); 386= (23 ,12); 387= (23 ,13); 388= (23 ,14); 389= (23 ,15); 390= (23 ,16); 391= (23 ,17); 392= (24 ,1); 393= (24 ,2); 394= (24 ,3); 395= (24 ,4); 396= (24 ,5); 397= (24 ,6); 398= (24 ,7); 399= (24 ,8); 400= (24 ,9); 401= (24 ,10); 402= (24 ,11); 403= (24 ,12); 404= (24 ,13); 405= (24 ,14); 406= (24 ,15); 407= (24 ,16); 408= (24 ,17); 409= (25 ,1); 410= (25 ,2); 411= (25 ,3); 412= (25 ,4); 413= (25 ,5); 414= (25 ,6); 415= (25 ,7); 416= (25 ,8); 417= (25 ,9); 418= (25 ,10); 419= (25 ,11); 420= (25 ,12); 421= (25 ,13); 422= (25 ,14); 423= (25 ,15); 424= (25 ,16); 425= (25 ,17); 426= (26 ,1); 427= (26 ,2); 428= (26 ,3); 429= (26 ,4); 430= (26 ,5); 431= (26 ,6); 432= (26 ,7); 433= (26 ,8); 434= (26 ,9); 435= (26 ,10); 436= (26 ,11); 437= (26 ,12); 438= (26 ,13); 439= (26 ,14); 440= (26 ,15); 441= (26 ,16); 442= (26 ,17)	335,. . . ,429
DATA TYPE	integer	decimal
MISSING DATA CODES

VARIABLES (ATTRIBUTES):

FILE NAME OR #ABOVE (all in which the variable appears)	2
ABBREVIATION (as it appears on the data file)	none_BIG GRID QUADRAT ELEVATIONS (revised June 27, 2002) north_
NAME OF VARIABLE	Elevation of the each of the grid points on the LFDP as recorded.
DEFINITION OF VARIABLE	Elevation of the each of the grid points on the LFDP as recorded by the surveyor's on a 20 m x 20 m grid. The relative position of the data points represents the location of the grid point in space. There are 17 grid points East to West (defining 16 20 x 20 m quadrats) and 26 grid points South to North (defining 25 20 m x 20 m quadrats)
UNIT	meter
PRECISION	±0.1
RANGE OR LIST OF VALUES	335,. . . ,429
DATA TYPE	decimal
MISSING DATA CODES	none

Observations: The surveyor's data was run through a topography program written by E.Everham and N.Pederson: APSECT13.FOR. The values generated are for the grid cell, not the control points. So, there are only 16 columns and 25 rows of data.

COMPUTATIONAL METHODS:

Variable Name	Formula

FOR DATA MANAGER USE ONLY

DATE OF LAST REVIEW: March 17, 2010
DATE OF LAST ENTRY: January 30, 1992
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED ENTERED: 1992
FILED: 1992
ON-LINE; 2002
REVIEWED BY RESEARCHER: FILING MEDIA:
NAME OF DOCUMENTATION FILE: lterdb46.htm
NAME OF ON - LINE CATALOG: LTERDBAS
RECORD #: 46
DOCUMENT TYPE: magnetic media (paper also)
PRIORITY TO BE ENTERED: second

Rev. date of this form: 8 June 2001, modified June 4, 2008