Ecological bases of sustainability in reconstructed tropical ecosystems, Huertos Project

Subject and Keywords:
Subject: Soil fertility
Keywords: agriculture, agroforestry, allocation, biomass, cations, Cedrela odorata, compensation, competition, complementarity, Cordia alliodora, dicots, dicotyledons, ecosystem design, Euterpe macrospadix, Euterpe oleracea, forest edges, Heliconia imbricata, herbivory, Huertos, Hyeronima alchorneoides, leaching, leaf area, life form diversity, monocots, monocotyledons, nitrogen, nutrients, Piper spp., phosphorus, plant competition, productivity, resprouting, restoration, root, roots, root competition, root density, root systems, shading, soil nutrients, solar radiation, starch, sustainability, tropical ecosystems

Author(s):
John J. Ewel
USDA Forest Service
Pacific Southwest Research Station
Institute of Pacific Islands Forestry
1151 Punchbowl Street, Suite 323
Honolulu HI 96813
e-mail: jackewel@gte.net

Other Agents:
Permanent staff (@ La Selva): Miguel Cifuentes (Project Manager); Virgilio Alvarado, Olman Paniagua, Silvino Villegas (Field Assistants); Walter Cruz, Gilberth Hurtado, Roger Gómez (Field workers).

Students (graduate and undergraduate) & Collaborators:
John Bellow, Dawn Berggren, Seth Bigelow, John Blanchard, Matthew Casey, Fabio Chaverri, David Coleman, Lee Dyer, Elena Florian, Arnoldo Gadea, Alicia Galo, Grant Gentry, Jeffrey Gerwing, Marco V. Gutiérrez, Jeremy Haggar, Bruce Haines, Liam Heneghen, Ankila Hiremath, Matthew Kelty, Rachel Krach, Louis LaPierre, Fabian Menalled, Paul Rich, Susan Stevens-Hummel

Funding Sources:
National Science Foundation Award, Long-term Research in Environmental Biology

Abstract:
Extensive deforestation and population growth have created a desperate need for both forest restoration and sustainable systems of land use in the humid tropical lowlands. Using nature as model, we work with the three most successful life forms in the humid tropics in an effort to understand the ecological underpinnings of sustainability. The experiments are of two kinds: one, designed to assess the role of diversity on sustainability, consists of tree plantations grown with and without two other successful life forms—a palm and a giant, long-lived herb; the other, designed to determine the impact of rotation frequency on sustainability, consists of tree plantations cut and replanted at intervals of one, four, and sixteen years. The ecological responses measured fall into three broad categories (1) maintenance (or loss) of soil fertility, (2) responsiveness to pests, and (3) productivity. By locating the experiments at a readily accessible and much-visited field station, we hope they serve as an outdoor laboratory for research, education, and demonstration.

EXPERIMENTAL DESIGN:
The experiments are designed to address two fundamental ecological questions regarding sustainability: 1.) What are the impacts of diversity? and 2.) What are the impacts of cutting frequency? The first question focuses on the low end of the diversity spectrum and is addressed by comparing ecosystem processes in communities containing either one species (a tree), or three species (the tree plus a palm plus a giant herb). The second question is addressed by measuring ecosystem processes in tree monocultures felled (and replanted) at three frequencies: annual, every four years, and uncut.

We use six plant species in our experiment. Three are trees (Hyeronima alchorneoides [Euphorbiaceae], Cedrela odorata [Meliaceae], and Cordia alliodora [Boraginaceae]), and three are large-stature, perennial monocots (Euterpe macrospadix and E. oleracea [Arecaceae] and Heliconia imbricata [Heliconiaceae]). There are three such experiments, each defined by the tree species used, and each experiment is replicated three times. The plantations were established in 1991.

Trees are planted in rows and columns, such that every individual is 2.0 m from its six nearest conspecifics. In plots containing multiple life forms, palms were planted in every other column and the heliconias in the remaining columns. The palms were planted between every other pair of trees in a column, whereas heliconias were planted at each inter-tree space; thus, the density of heliconias is approximately twice of that of palms. As initially planted, each tree had 3.46 m2 of growing space, although this area has increased due to thinnings and mortality.

Supplementary plots are used to assess the impacts of plant density and higher diversity. Density is evaluated using a Nelder design, whereby plants (of a single species) are grown at sequentially increasing distances along the radii of a circle (or semicircle). The effects of higher diversity (and the possible risk aversion that this provides) are assessed on two plots in which all species (except Heliconia) are grown in mixtures, and two extremely diverse plots containing naturally occurring succession vegetation of the same age as the oldest plantations.

Plot sizes vary, depending on their purpose. In the main experiments (i.e., those that address the diversity and rotation-frequency gradients), subplots harvested annually are 10 x 40 m, those harvested every 4 yr are 20 x 40 m, and the long-rotation monocultures and polycultures are 30 x 40 m. The plots containing five species each occupy 1600 m2. Additional information, including maps of the plot layouts and schematics of experimental design, is on the project's webpage .

Data Description:
A half-time data manager serves the data synthesis and analysis needs of all researchers affiliated with the project. Data are verified and entered as soon as they come in from the field or are downloaded from instruments, and are then transmitted to the data manager. We use a data-storage procedure designed and used very successfully in conjuntion with a previous research project, modified using some of the protocols developed as part of the National Science Foundation's Long Term Ecological Research Program. Different types of data are categorized into "tasks" and data for each task include the same identifiers (codes for date, type of data, location, etc.) in the same fields, followed by task-specific field codes for response variables. Each investigator responsible for a task fills out several electronic forms describing the data. These contain metadata (description of the study, methods, dataset, etc.) and forms describing variables (precision, units, any codes used, etc.). The forms for any particular kind kind of data can be accessed from the list below.

The data are available (read-only) to all investigators affiliated with the project, but only the data manager makes changes to archived datasets. All data are potentially available for distribution to anyone in the research community, although each investigator is granted control of access to unpublished data sets for which s/he is primarily responsible. Spatial data are available through the Geographic Information System of the Organization for Tropical Studies, Inc., described at .

The project currently involves more than 50 kind of data, or tasks, as listed below. [SP seguido por el número de la tarea, después del título, indica que los formularios también están disponibles en español.]
TASK # TASK DESCRIPTION
1001 Rainfall
1002 Throughfall and throughfall chemistry
1003 Site microenvironment
1004 Evaporation
1005 Rain interception
1006 Canopy water storage
1007 Boundary layer conductance
1008 Stemflow volume
1009 Stemflow chemistry
1010 Fisheye photos
1011 Throughfall chemistry
1102 Leaf area loss
1200 Species dictionary
1201 Tree inventory
1200 Cover
1203 Litterfall
1204 Tree biomass
1205 Longevity
1206 Invasibility point intercepts
1207 Invasibility biomass
1208 LAI
1209 Tabular LAI
1210 Crown structure
1211 Leaf distribution
1212 Understory resources
1213 Tree prunings
1214 Nutrients in biomass
1215 Initial biomass
1216 Cedrela phenotypes
1217 Planting dates
1218 Nutrients in plant litter
1219 Stomatal conductance
1220 Plant family codes
1221 Potometers
1222 Foliar nutrient resorption
1223 Weed harvest
1224 Photosynthesis (P max)
1225 Photosynthesis (A-Ci)
1226 Leaf longevity
1227 Tree thinnings
1228 Photosynthesis (Light-response curves)
1229 Foliar nutrients concentration
1230 Phenology
1301 Large roots
1302 Fine roots - annual sampling
1303 Fine roots - decomposition
1304 Fine roots - sequential samples
1305 Large roots - annual sampling
1401 Annual soil sampling -SP 1401-
1402 Nitrogen mineralization
1403 Phosphorus fraction
1404 Leachate nutrients
1405 Soil water contents
1406 TDR calibration
1407 Soil evaporation
1408 Chloride
1410 Soil organic matter
1500 Starch in Cedrela

Language(s):
EN, SP

Spatial and Temporal Coverage:
Spatial coverage: La Selva Biological Station; Las Vegas Annex, peninsula where Puerto Viejo and Sarapiquí rivers join. Follow STR (Tres Rios Trail) to 1300 m. La Selva GIS coordinates: (-300) - 300, (-100) - (-500).
Temporal coverage: 1991-1999

Longitude and Latitude:
10’ 26" N, 83’ 59" W

Taxonomic Coverage:
Hyeromina alchorneoides Allemao (Euphorbiaceae)
Cordia aliodora (R&P) Cham. (Boraginaceae)
Cedrela odorata L. (Meliaceae)
Heliconia imbricata (Kuntze) Heliconiaceae
Euterpe oleracea Mart, E. macrospadix (Arecaceae)

Form and Size:
Foxpro (*.dbf), database files of various sizes (depending on type of data)

TFS Name:
ots-laselva

Contacts:
John J. Ewel, Principal Investigator
Institute of Pacific Islands Forestry
1151 Punchbowl St., Suite 323
Honolulu HI 96813 USA
e-mail: jackewel@gte.net
phone: 808-552-8230/ fax: 808-522-8236

Miguel Cifuentes-Jara, Project Manager
La Selva Biological Station
Apdo 676-2050 San Pedro,
Costa Rica
e-mail: huertos@sloth.ots.ac.cr
phone: 506-766-6565/ fax: 506- 766-6535

Availability:
Restricted (see Contacts)

Relation to Other Datasets:
(none)

Metadata Log:
1998-03-18 09:49:13: Created by Pablo Arroyo (parroyo)

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1998-11-23 13:23:48: Modified by vnielsen:
1998-11-24 14:30:00 Modified by Miguel Cifuentes, under supervision of Vanessa Nielsen (vnielsen).

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1999-01-21 20:32:42: Modified by barbozac:
Modified by Miguel Cifuentes and John J. Ewel

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1999-01-21 20:39:12: Modified by barbozac:
Miguel Cifuentes

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1999-01-21 20:41:51: Modified by barbozac:
By Miguel Cifuentes

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1999-02-01 16:07:54: Modified by barbozac:
Modifications made by Miguel Cifuentes

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1999-02-01 16:14:38: Modified by barbozac:
Minor modifications by Miguel Cifuentes

Additional Information:
PUBLICATIONS:

Heneghan, L., Coleman, D. C., Zou, X., Crossley, D. A. & Haines, B. L. 1999. Soil microarthropod contributions to decomposition dynamics: tropical and temperate comparisons of a single substrate (Quecus prinus L.) Ecology. (in press).

Kelty, M. J. 1999. Species interactions, stand structure, and productivity in agroforestry plantations. in: M. Ashton and F. Montagnini (eds.) The Silvicultural Basis for Agroforestry Systems. CRC Press, Boca Raton, Florida. (in press).

Coleman, D. C., Heneghan, L. & Crossley, D. A. Jr. 1998. Biodiversity and decomposition in temperate and tropical forests. International Soil Science Society (in press).

Ewel, J. J. Natural systems as models for the design of sustainable systems of land use. Chapter 3, in: T. Lefroy, R. Hobbs, M. O’Connor, & J. Pate (eds.) Agriculture as Mimic of Natural Ecosystems. Kluwer, Dordrecht, The Neatherlands. (in press).

Ewel, J. J. and A. J. Hiremath. 1998. Nutrient use efficiency and the management of degraded lands. In: B. Gopal, P. S. Pathak and K. G. Saxena (eds.) Ecology Today: An Anthology of Contemporary Ecological Research. International Scientific Publications, New Delhi. 199-215 pp.

Heneghan, L., Coleman, D. C., Zou, X., Crossley, D. A. & Haines, B. L. 1998. Soil microarthropod community structure and litter decomposition dynamics: a study of tropical and temperate sites. Applied Soil Ecology 9: 33-38.

Heneghan, L., Coleman, D. C., Zou and X., Crossley, D.A. Jr. 1998. The influence of diverse microarthropod assemblages on the nitrogen dynamics of decomposing chesnot oak (Quercus prinus L.) litter in mesic temperate and tropical forest. Applied Soil Ecology. [accepted, pending minor revisions]

Menalled, F. D., M. J. Kelty, and J. J. Ewel. 1998. Canopy development in tropical tree plantations: a comparison of species mixtures and monocultures. Forest Ecology and Management 104:249-263

Haggar, J.P. & J.J. Ewel. 1997. Primary productivity and resource partitioning in model tropical ecosystems. Ecology 78: 1211-1221.

Ewel, J., Cifuentes, M. and Hiremath, A. 1997. El mito de la luz como limitante del crecimiento: efecto de la competencia por nutrimentos sobre los árboles. In: III Congreso Forestal Nacional, San José, Costa Rica, MINAE, pp. 305-307.

Hiremath, A., Ewel, J. and Cifuentes, M. 1997. Pérdida de nutrimentos por escorrentía de fuste en ecosistemas tropicales simplificados. In: III Congreso Forestal Centroamericano, San José, Costa Rica, Impresos Belén, pp. 31-33.

Ewel, J.J. 1997. Ecosystem processes and the new conservation theory. Chapter 20, pp. 252-261 in: S.T.A. Pickett, R.S. Ostfeld, M. Shachak, & G.E. Likens (eds.). Ecology and the New Conservation Theory. Proceedings of the VI Cary Conference. Chapman & Hall, N.Y.

Ewel, J.J. & S.W. Bigelow. 1996. Plant life forms and tropical ecosystem functioning. Chapter 6, pp. 101-126 in: G.H. Orians, R. Dirzo, & J.H. Cushman. (eds.). Biodiversity and Ecosystem Processes in Tropical Forests. Springer-Verlag, N.Y.

Haggar, J.P. & J.J: Ewel. 1995. Establishment, resource acquisition, and early productivity as determined by biomass allocation patterns of three tropical tree species. Forest Science 41: 689-708.

Rodgers, H.L., M.P. Brakke, & J.J. Ewel. 1995. Shoot damage effects on starch reserves of Cedrela odorata. Biotropica 27: 71-77.

Gerwing, J.J. 1995. Competitive effects of three tropical tree species on two species of Piper. Biotropica 27: 47-56.

Menalled, F., M. Kelty & J. Ewel. 1994. Canopy development of monocultures and species mixtures in forest plantations in Costa Rica. In: Proceedings, Symposium of Mixed Stands, IUFRO, Portugal-54 01:10-11.

Haggar, J.P. & J.J. Ewel. 1994. Experiments on the ecological basis of sustainability: early findings on nitrogen, phosphorus and root systems. Interciencia 19: 347-351.

Ewel, J.J. 1993. The power of biology in the sustainable land use equation. Biotropica 25: 250-251.

Bigelow, S.W. 1993. Leaf nutrients in relation to stature and life form in a tropical rain forest. Journal of Vegetation Science 4: 401-408.

Galo, A. T., P.M. Rich & J.J. Ewel. 1992. Effects of forest edges on the solar radiation regime in a series of reconstructed tropical ecosystems. Proceedings, American Society for Photogrammetry and Remote Sensing 1992 Annual Meeting. Albuquerque, NM. pp. 98-108.


THESES AND DISSERTATIONS:

Hiremath, A. J. 1998. Nutrient Use Efficiency in Simplified Tropical Ecosystems. Ph.D. disseration. University of Florida, Gainesville. [due 12/98]

Bigelow, S. W. 1998. Stand Rotation Frequency as Determinant of Leaching in the Humid Tropics. Ph.D. dissertation. University of Florida, Gainesville. 145 p.

Hummel, S. 1997. Stand development of Cordia alliodora (Boraginaceae), a neotropical secondary forest tree in northern Costa Rica (1992-1996). Ph.D. dissertation. Oregon State University, Corvallis. 117 p.

Casey, M.T. 1996. Throughfall in a forestry plantation at La Selva Biological Station, Costa Rica. M.S. thesis, University of Tennessee, Knoxville. 101 p.

Menalled, F. D. 1996. Crown structure, light availability, and stand dynamics in forest plantations in Costa Rica: a comparison of species mixtures and monocultures. Ph.D. dissertation, University of Massachusetts, Amherst. 110 p.

Gerwing, J. J. 1993. Competitive effects of monocultures and a polyculture of three tropical tree species on understory plant growth. MS thesis. University of Florida. 53 p.