Contents
The
forests of the US Virgin Islands
How
is the survey information released?
What
does FIA do with the information?
What
doesn’t FIA do with the information?
For
more information, please contact:
The forests of the US Virgin Islands
Forests on the U.S. Virgin Islands of St. Croix,
The nature of the island environment and
often rugged mountain terrain may mean an increased emphasis and investment in
remote sensing technology over field visits and expanded use of remote sensing
for areas beyond forested ecosystems. Innovations piloted in the islands could
lead to improvements in the FIA technologies on the mainland. It has been
recognized that forested lands on tropical islands are unique because of the
high complexity and biological diversity that are found on very small land
bases. On islands, ecosystem components change dramatically with elevation and
topography, creating challenging conditions for conducting a strategic
inventory of forest resources.
Because there
are no previous forest inventories of the US Virgin Islands, this study will
initially refer to forest reference materials such as the “U.S.V.I. Vegetation
Community Classification System” published by The Nature Conservancy, and
vegetation maps produced by the Virgin Islands Conservation Data Center (University
of the Virgin Islands, #2 John Brewer's Bay,
St. Thomas, VI, 00802).
Individual tree
growth rates, expressed as diameter increments, provide insight into relative
tree vigor. Studies in Puerto Rico (Crowe and Weaver 1977, Weaver 1983,
Weaver and Birdsey 1990) and the Virgin Islands (Weaver 1990) provide results for many of the species
that will be encountered in this study.
However, there will gaps in the available literature that this study
will have to fill in the future, especially regarding tree growth rates, vigor
and mortality for dry and moist forest species the predominate on the outlying
Puerto Rican islands and the Virgin Islands.
Also, studies of tree damage in the past have concentrated on the incidence
of cull in the timber resource (Anderson et al. 1982), and other types of tree damage have
not been examined.
The effects of
hurricanes on Puerto Rican and Virgin Islands’ forests has also produced a
number of valuable publications regarding disturbance and succession in
Caribbean forests (Weaver 1989, Acevedo-Rodríguez and Sastre 1992, Quiñones 1992,
Weaver 1994, Dallmeier et al. 1998, Rogers and Reilly 1998, Weaver 1998, Whigham and Lynch 1998, Weaver 1999, Francis 2000, Lugo and
Frangi 2001, Ross et al. 2001, Walker et al. 2003, Wunderle
et al. 2003).
While there
have not been any studies that specifically examined forest understory
vegetation structure and diversity in the same way that is being proposed by
this study, several references exist on the species composition, forest
structure, and secondary succession for the Virgin Islands (Woodbury and Little 1976, Weaver and
Chinea 1987, Woodbury and Weaver 1987, Ray and Brown 1995, Ray et al. 1998,
Rogers and Reilly 1998) that can be used as general references.
Why a forest inventory?
There is a strong need to create awareness
among island residents, territorial/commonwealth legislatures and federal
agencies of the uniqueness of island ecosystems and the significant ecological
changes that they have been experiencing recently, manifesting themselves in
changes in land cover, land use, and biological diversity. Reports on forest
condition will be most useful in creating public awareness and crystallizing
action if they bring together available information describing the current
situation and recent trends; point out what the future will be like if the
trends are allowed to continue unchanged; build the case that with better
information resource managers can take steps to reinforce desirable trends and mitigate
undesirable trends; and highlight inventory and monitoring activities needed to
fill gaps, improve data quality, and enable resource managers to influence
trends in preferred ways.
The survey information will be useful to:
- Land use planners
- Urban planners
- Decision makers from local and
provincial governments
- Environmental action groups
- Businesses that use resources from the
forest
- General public
Forest inventory methods
As explained in detail in the publication “Puerto Rico’s Forest Inventory: Adapting the
USDA Forest Service’s Forest Inventory and Analysis Program to a Caribbean
Island” and
in the FIA fact sheet “Caribbean
Island’s Inventories” a
systematic sample of the forest will be measured by field crews on all forest
types and ownerships across the three islands.
St. Croix and St. Thomas are surveyed at approximately six-times the
intensity used in the continental US to ensure an adequate sampling of the
forests.
A
standard FIA subplot cluster, (for details see: USDA
Forest Service FIA Field data collection procedures for Phase 2 plots. Manual
Version 1.6), was installed in areas that met the
Caribbean FIA criteria for forested land (a contiguous area > 0.4 ha, or
> 30 m wide for forested strips, with >10% canopy coverage in
trees). Non-forest plots were located
and briefly described without any further data collection.
Basic tree information
For each tree within the plot, the following data are recorded:
Azimuth from plot center to the tree
Distance to tree from plot center
Species
Diameter at breast height (1.37 m)
Height to top of tree
Height to base of live crown
Crown width (average width based on two
measurements: N-S and E-W widths)
Percent of normal live crown that is in leaf
Additional tree information
The additional information collected from each tree included the following:
Percentage of epiphytic foliage in the tree
crown
Uncompacted live crown
ratio
Crown light exposure
Crown position
Vigor class
Crown density
Crown dieback
Foliage transparency
Forest health monitoring
Tree damage, vigor, mortality and
regeneration
erosion
compaction
samples
of mineral soil and forest floor
will
be analyzed for bulk density, total carbon, total nitrogen,
plant
available phosphorous and sulfur, exchangeable cations, and pH
Vegetation diversity and structure
Down woody debris and forest fire fuels
How is the survey information released?
After the forest surveys are completed, the
information is released in a report published by the Southern Research Station.
This information is made available to anyone wishing to receive a copy. The
information will also be made available for downloading from the Forest
Inventory and Analysis Website.
However, the actual plot locations will not
be made public to protect landowner confidentiality.
What does FIA do with the information?
The FIA Program collects, analyzes, and
reports information on the status and trends of America’s forests: how much
forest exists, where it exists, who owns it, and how it is changing, as well as
how the trees and other forest vegetation are growing and how much has died or
has been removed in recent years. This information can be used in many ways,
such as in evaluating wildlife habitat conditions, assessing the sustainability
of
ecosystem management practices, and
supporting planning and decision-making activities undertaken by public and private
enterprises. After the forest surveys
are completed, the data is entered into database systems for compiling into the
FIA reports.
What doesn’t FIA do with the information?
The information and data gathered during the FIA survey period, although a matter of public record after the surveys are complete, is not used as a basis for taxation records and the plot locations are not shared with any other government agency due to the confidentiality of these locations.
Literature cited
Acevedo-Rodríguez, P., and I. Sastre. 1992. Efectos del Huracán Hugo y posterior recuperación en el bosque de Toro Negro, Puerto Rico. Acta Científica 6:15-28.
Anderson, R. L., R. A. Birdsey, and P. J. Barry. 1982. Incidence of damage and cull in Puerto Rico's timber resource, 1980. Resource Bulletin SO-88, USDA Forest Service, Southern Forest Experiment Station, New Orleans, LA.
Crowe, T. R., and P. L. Weaver. 1977. Tree growth in moist tropical forest of Puerto Rico. Research Paper ITF-22, USDA Forest Service, Institute of Tropical Forestry, Rio Pedras, Puerto Rico.
Dallmeier, F., J. A. Comiskey, and F. N. Scatena. 1998. Five years of forest dynamics following hurricane Hugo in Puerto Rico's Luquillo Experimental Forest. Pages 231-248 in F. Dallmeier and J. A. Comiskey, editors. Forest biodiversity in North, Central and South America and the Caribbean. Research and Monitoring. Parthenon Publishing Group, Washington, D.C.
Francis, J. K. 2000. Comparison of hurricane damage to several species of urban trees in San Juan, Puerto Rico. Journal of Arboriculture 26:189-197.
Lugo, A. E., and J. L. Frangi. 2001. Changes on a floodplain
forest floor after Hurricane Hugo. Pages 14 in,
Rio Piedras, PR.
Quiñones, F. 1992. History
of hurricanes in Puerto
Rico, 1502-1989. Acta Científica 6:3-14.
Ray, G. J., and B. Brown. 1995. The structure of five successional stands in a subtropical dry forest, St. John, U.S. Virgin Islands. Caribbean Journal of Science 31:212-222.
Ray, G. J., F. Dallmeier, and J. A. Comiskey. 1998. The structure of two subtropical dry forest communities on the island of St. John, U.S. Virgin Islands. Pages 367-384 in F. Dallmeier and J. A. Comiskey, editors. Forest biodiversity in North, Central and South America, and the Caribbean. Parthenon Publishing Group, Washington. D.C.
Rogers, C. S., and A. E. Reilly. 1998. Insights into forest dynamics from long-term monitoring on St. John, U.S. Virgin Islands. Pages 323-332 in F. Dallmeier and J. A. Comiskey, editors. Forest Biodiversity in North, Central and South American, and the Caribbean. Parthenon Publishing Group, Washington, DC.
Ross, M. S., M. Carrington, L. J. Flynn, and P. L. Ruiz. 2001. Forest succession in tropical hardwood hammocks of the Florida Keys: effects of direct mortality from Hurricane Andrew. Biotropica 33:23-33.
Walker, L. R., D. J. Lodge, S. M. Guzmán-Grajales, and N. Fletcher. 2003. Species-specific seedling responses to hurricane disturbance in a Puerto Rican rain forest. Biotropica 35:472-485.
Weaver, P. L. 1983. Tree growth and stand changes in the subtropical life zones of the Luquillo Mountains of Puerto Rico. Research Paper SO-190, USDA Forest Service, Southern Forest Experiment Station, New Orleans, LA.
Weaver, P. L. 1989. Forest changes after hurricanes in Puerto Rico's Luquillo mountains. Interciencia 14:181-192.
Weaver, P. L. 1990. Tree diameter growth rates in Cinnamon Bay watershed, St. John, U.S. Virgin Islands. Caribbean Journal of Science 26:1-6.
Weaver, P. L. 1994. Effects of hurricane Hugo on trees in the Cinnamon Bay watershed, St. John, U.S. Virgin Islands. Caribbean Journal of Science 30:255-261.
Weaver, P. L. 1998. The effects of environmental gradients on hurricane impact in Cinnamon Bay watershed, St. John, U.S. Virgin Islands. Pages 333-348 in F. Dallmeier and J. A. Comiskey, editors. Forest Biodiversity in North, Central and South American, and the Caribbean. Parthenon Publishing Group, Washington, DC.
Weaver, P. L. 1999. Impacts of Hurricane Hugo on the dwarf cloud forest of Puerto Rico's Luquillo Mountains. Caribbean Journal of Science 35:101-111.
Weaver, P. L., and R. A. Birdsey. 1990. Growth of secondary forest in Puerto Rico between 1980 and 1985. Turrialba 40:12-22.
Weaver, P. L., and J. D. Chinea. 1987. A phytosociological study of Cinnamon Bay watershed, St. John, U.S. Virgin Islands. Caribbean Journal of Science 23:318-336.
Whigham, D. F., and J. L. Lynch. 1998. Responses of plants and birds to hurricane disturbances in a dry tropical forest of Quintana Roo, Mexico. Chapter 9. Pages 165-186 in F. Dallmeier and J. A. Comiskey, editors. Forest biodiversity in North, Central and South America and the Caribbean. Research and Monitoring. Parthenon Publishing Group, Washington, D.C.
Woodbury, R. O., and E. L. Little. 1976. Flora of Buck Island Reef National Monument (U.S. Virgin Islands). Forest Service Research Paper ITF-19 Institute of Tropical Forestry, USDA Forest Service, Rio Piedras, Puerto Rico.
Woodbury, R. O., and P. L. Weaver. 1987. The vegetation of St. John and Hassel island, U.S. Virgin Islands. Research/Resources Management Report SER-83, U.S. Department of the Interior, National Park Service, Atlanta, GA.
Wunderle, J. M., J. Mercado, E., B. Parresol, F. J. Bird-Píco, and E. Terranova. 2003. Movements and habitat use by Puerto Rican boas (Epicrates inornatus) in a hurricane impacted forest. in, Río Piedras, Puerto Rico.
For more information, please contact:
If you have questions, comments, or want to
receive a copy of the final FIA Survey Reports for
• Request a hardcopy printed report:
Southern Research
Station
Attn:
Publications
Make sure to include the title and
publication.
• Go to the Southern Research Station
Website:
<www.srs.fs.fed.gov> and search under publications.
(You can also go to the Website to order a
hardcopy publication).
• Go to the
<www.srsfia2.fs.fed.us and search for the
publication.
