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.
NOTES:
| Xiaoming Zou | xzou@lternet.edu |
| Eda C. Melendez-Colom | emelendez@lternet.edu |
DATA SET IDENTIFIER : Earthworms in abandoned tropical pastures
PROJECT TITLE : Earthworm Population Dynamics
PROJECT DESCRIPTION : Plant communities may impose strong control on soil fauna populations. We compared and examined patterns of earthworm abundance, species composition, and distribution pattern of earthworms in tree plantations and secondary forests of Puerto Rico. Our results indicate that variation in plant species composition and soil properties between plant communities can trigger differences in earthworm abundance and distribution pattern within a tropical wet forest.
LTER CORE AREAS: (Annotate all that apply)
| Population Dynamics |
| Disturbance Patterns |
LEF LTER 1 RESEARCH TOPIC: (Annotate all that apply)
| Spatial and temporal distribution of population |
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
|
|
|
Earthworm density and biomass |
eart2raw.txt | June 21, 1993 | one time sample | July 28, 1993 |
|
2
|
Summary of density and biomass data | June 21, 1993 | one time sample | July 28, 1993 |
RESEARCH LOCATION: Sabana (18° 18'N, 65° 50'W) in the northeastern Luquillo Mountains of Puerto Rico.
INVESTIGATORS:
PRINCIPAL INVESTIGATORS E-MAIL
address
| Xiaoming Zou | xzou@lternet.edu |
OTHER INVESTIGATORS
| Grizelle Gonzalez | ggonzalez@fs.fed.us |
CONTACT PERSON E-MAIL address Phone Number(Include area code)
| Xiaoming Zou | xzou@lternet.edu | 787-764-0000 (x2867) |
SOURCE OF FUNDING (SPONSOR): NSF-LTER
DATA SET ABSTRACT: Plant community succession alters the quantity and chemistry of organic inputs to soils. These differences in organic input may trigger changes in soil fertility and faunal activity. We examined earthworm density and community structure along a successional sequence of plant communities in abandoned tropical pastures in Puerto Rico. The chronological sequence of these plant communities were pasture, grass-vine-fern, shrub-small tree, and forest. Earthworm density was the highest in pasture (831 worms/m2 in top 0.25 m soil), decreased as secondary succession proceeded, and reached the lowest (32 worms/m2) in the forest. Whereas only soil feeding Pontoscolex corethrurus was present in the pasture and grass-vine-fern communities, both soil and litter feeding worm species were found in the shrub-small tree and forest communities. Ground litter biomass had a negative correlation with earthworm density. Soil water content differed slightly among the successional communities, but were unlikely to play an important role in triggering differences in worm density among these abandoned lands. Soil pH values did not differed along the successional changes. These results suggest that decrease in earthworm density and increase in worm community diversity during secondary succession may result from changes in the quantity and chemistry of organic inputs, rather than in soil properties. We conclude that successional development from grass-dominated pastures to woody species-dominated forests reduces earthworm density and diversifies worm community structure in humid tropical soils.
DATA SET METHODS: Using air photos taken in 1936, 1951, 1964, 1971, 1977, 1983, 1988, 1991 and 1993, we were able to locate four sites adjacent to each other on the same hill slope north of the Rio Sabana. Three sites were deforested and converted to pastures prior to 1936, two of which had subsequently been abandoned by 1971 and 1988, and one has been maintained as pasture. The fourth site has been forest since 1936. The site abandoned in 1971 has developed into a shrub-small tree community (Aide et al., 1995) dominated by species in Melastomataceae (Miconia prasina, M. impetiolarias, M. racemosa) and Rubiaceae (Palicourea riparia, Psychotria brachiata). The more recently abandoned site has developed into a grass-vine-fern community. Soils in all the study sites are Oxisols, belonging to the Zarzal series with high clay content. Earthworms were sampled between June 21 and July 28, 1993. Three 0.25 m2 (pasture and grass-vine-fern communities) or 0.5 m2 (shrub-small tree and forest communities) plots were located 15 m apart in each site along the slope. Ground litter (leaves and twigs < 2 mm) were collected in each plot and stored in plastic bags. Soils in the upper 250 mm were then removed onto a cloth sheet. Earthworms were hand- sorted and stored in plastic bags in a cooler with ice. A soil sample was taken from each plot and placed in a plastic bag for measuring pH and water content. Ground litter biomass was obtained after drying twigs and leaves at 60 °C for at least 72 hrs. Fresh weight of earthworms was acquired after the worms were rinsed with water and dried with paper towels on the same day they were collected. Soil moisture content was calculated for each site by oven-drying 15 g of fresh sample at 105 °C for 48 hrs. Soil pH was measured using a paste of 1:1 ratio of fresh soil and deionized water. The analyses of variance and Scheffe's multiple range test were employed to examine differences among successional communities. The significance level was set at alpha = 0.10.
REFERENCES :
Ewel J. J. and Whitmore J. L. (1973) The ecological life zones of Puerto Rico
and the U.S. Virgin Islands. USDA Forest Service Research Paper. ITF-18.
Institute of Tropical Forestry, Rio Piedras, Puerto Rico.
Scatena F. N. (1989) An introduction to the physiography and history of the Bisley Experimental Watersheds in the Luquillo Mountains of Puerto Rico. USDA Forest Service General Technical Report SO-72. New Orleans, Louisiana.
Aide T. M., Zimmerman J. K., Herrera L., Rosaria M. and Serrano M. 1995. Forest recovery in abandoned tropical pastures in Puerto Rico. Forest Ecology and Management 77:77-86.
CROSS-REFERENCES (other data sets related to this one): LTERDBAS #91: Earthworms in tropical tree plantations and secondary forests
SAMPLE LOCATION : ITES, Data Manager's File DM-002 , Drawer #1
STORAGE SITES (of data files): N/A
KEYWORDS : Pontoscolex corethrurus, Deforestation, Cattle grazing, Earthworm succession, Puerto Rico
LEF LTER OFFICIAL KEYWORDS (See table): SABANA, SUBTROPICAL, WET, SECOND FOREST, TERRESTRIAL, TREES, PEER REVIEWED JOURNAL
PUBLICATIONS :
Zou, X. and G. González.1997. Changes in earthworm density and community
structure in abandoned tropical pastures. Soil Biology Biochemistry29:627-629
DISSEMINATION : UNRESTRICTED
*WILL HAVE TO BE APPROVED BY LTER PRINCIPAL INVESTIGATORS: J. ZIMMERMAN, A. LUGO , D.J. LODGE
SITES DESCRIPTIONS: This study was conducted at Sabana (18° 18'N, 65° 50'W) in the northeastern Luquillo Mountains of Puerto Rico. Native forest is described as subtropical wet forest (Ewel and Whitmore 1973) dominated by tabonuco trees (Dacryodes excelsa). Elevation is about 420 m above sea level, and the mean monthly temperatures vary from 22-26 °C. Annual precipitation is approximately 3500 mm (Scatena 1989).
Geographical positional system (GPS) Coordinates for each location:
| location | latitude | longitude |
| hill slope north of the Rio Sabana | 18° 18' N | 65° 50' W |
| File Name or # above (all in which the variable appears) | 1,2 | 1, 2 | 1, 2 | 2 |
| Abbreviation (as it appears on the data file) | SUCCESSIONAL_COMMUNITY | DENSITY(NO/M2) | WORM_BIOMASS(G/M2) | PERCENT |
| NAME OF VARIABLE | Plant Community | Density of worms | Worm biomass | Anecic worm weight percent |
| DEFINITION OF VARIABLE | The chronological sequence of plant communities observed | Number of earthworms found per square meter | Ground litter biomass obtained after drying twigs and leaves at 60 °C for at least 72 hrs. Common letters within a column in summary (earth2tab.txt data file) indicate no significant difference (Scheffe's multi-range test alpha = 0.10) between successional communities. | Percent of anecic worm weight |
| UNIT | numberPerMeterSquared | gramsPerSquareMeter | ||
| PRECISION | 0.1 | |||
| RANGE OR LIST OF VALUES | pasture, grass-vine-fern, shrub-small-tree, forest |
|||
| DATA TYPE | alphabetic | integer | decimal | integer |
| MISSING DATA CODES |
VARIABLES (ATTRIBUTES):
SOIL_H2O_percent,SOIL_PH,GROUND_LITTER(G/M2)
| File Name or # above (all in which the variable appears) | 2 | 2 | 2 |
| Abbreviation (as it appears on the data file) | SOIL_H2O_PERCENT | SOIL_PH | GROUND_LITTER(G/M2) |
| NAME OF VARIABLE | Soil moisture content | Soil pH | Ground litter biomass |
| DEFINITION OF VARIABLE | Soil moisture content calculated for each site by oven-drying 15 g of fresh sample at 105 °C for 48 hrs. Common letters within a column in summary indicate no significant difference (Scheffe's multi-range test alpha = 0.10) between successional communities. | Soil pH was measured using a paste of 1:1 ratio of fresh soil and deionized water. Common letters within a column in summary indicate no significant difference (Scheffe's multi-range test alpha = 0.10) between successional communities. | ground litter biomass during secondary
succession in abandoned tropical past in Puerto Rico. Common letters within a column in summary indicate no significant difference (Scheffe's multi-range test alpha = 0.10) between successional communities. |
| UNIT | gramsPerSquareMeter | ||
| PRECISION | 0.1 | 0.1 | |
| RANGE OR LIST OF VALUES | |||
| DATA TYPE | alphanumeric | alphanumeric | alphanumeric |
| MISSING DATA CODES |
COMPUTATIONAL METHODS:
| VARIABLE NAME | FORMULA OR DESCRIPTION |
FOR DATA MANAGER USE ONLY
DATE OF LAST REVIEW:
February 3, 2009
DATE OF LAST ENTRY: July 28, 1993
STAGE OF DATA SET MANAGEMENT (dates):
RECEIVED: 1997
ENTERED:
FILED: 1997
ON-LINE REVIEWED BY RESEARCHER
FILING MEDIA:
NAME OF DOCUMENTATION FILE : lterdb92.htm
NAME OF ON - LINE CATALOG :LTERDBAS
RECORD # : 92
DOCUMENT TYPE : magnetic media
PRIORITY TO BE ENTERED :N/A
Rev. date of this form: 15 July 2001