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***Compass*--Winter 2001**

**The Southern Research Station**

**Recent Publications Catalogue**

**(<http://www.srs.fs.fed.us/pubs/>)**

**Characterizing and Measuring Southern Forested Wetlands**

For many of us, the term "forested wetlands" conjures images of cypress
knees and Spanish moss, and sounds of birds, frogs, and crickets, either
from personal experience or courtesy of movies or music. Naturally, the
complexity of the forested wetlands ecosystem extends much wider and
goes much deeper. Definitions of forested wetlands can vary
considerably. Measuring carbon storage below ground requires a different
model from those used in other forested areas. Southern Station
scientists and colleagues explore these and other issues in four
*Compass* publications.

*Forested Wetlands of the Southern United States: A Bibliography*
describes forested wetland as a variety of habitat types ranging from
bottomland hardwood forests to alluvial swamp forests that occur on
river floodplains. *Wetland Forest Statistics for the South Atlantic
States* presents information about timberland with hydric vegetation,
hydric soil, and a wetland hydrology. Mark J. Brown, resource analyst,
Greg M. Smith, forester, and Joseph McCollum, mathematical statistician,
present findings about area, distribution, and ownership; stand size and
age structure; forest management types and detailed forest types;
physiography; volume, growth, removals, and mortality; and disturbances,
condition, and opportunities.

The authors of *Existing Soil Carbon Models Do Not Apply to Forested
Wetlands* evaluated 12 modeling simulations. According to authors C.C.
Trettin, B. Song, M.F. Jurgenson, and C. Li, these models fail to assess
accurately the cycling of nutrients and elements or carbon dynamics with
respect to global change. Although wetlands occupy a relatively small
proportion of Earth's terrestrial surface (less than 3 percent), they
contain a disproportionate share of the terrestrial carbon pool (15 to
22 percent). Only 3 of 12 models evaluated allow for anaerobic
conditions; none contains components for anoxia, ground water hydrology,
multiple organic and physical soil layers, or a daily time-step, all of
which are necessary when modeling soil carbon (C) in wet soils. Southern
Station scientist Trettin and his co-authors present a wetland soil C
model framework. Their proposed synthesis would be appropriate when
considering soil C dynamics at multiple spatial scales and where the
land area considered includes both wetland and upland ecosystems.

The Southern Research Station published *Forested Wetlands of the
Southern United States: A Bibliography*. This comprehensive list of
references to varied studies conducted in these forest types could
benefit researchers, students, managers, and other interested people.
Citations date from 1923 to 2001.

Allen, J.A.; Keeland, B.D.; Stanturf, J.A.; and others. 2001. **A guide
to bottomland hardwood restoration.** U.S. Geological Survey, Biological
Resources Division Information and Technology Report
USGS/BRD/ITR--2000-0011; Gen. Tech. Rep. SRS-40. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station.
Asheville, NC. 132 p. **(10)**

Brown, Mark J.; Smith, Greg M.; McCollum, Joseph. 2001. **Wetland forest
statistics for the South Atlantic States.** Resour. Bull. SRS-62.
Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern
Research Station. 52 p. **(20)**

Conner, William H.; Hill, Nicole L.; Whitehead, Evander M.; and others.
2001. **Forested wetlands of the Southern United States: a
bibliography.** Gen. Tech. Rep. SRS-43. Asheville, NC: U.S. Department
of Agriculture, Forest Service, Southern Research Station. 133 p.
**(11)**

Trettin, C.C.; Song, B.; Jurgensen, M.F.; Li, C. 2001. **Existing soil
carbon models do not apply to forested wetlands**. Gen. Tech. Rep.
SRS-46. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. 10 p. **(14)**

**Inventorying Southern Forests**

The intense national pressure on forests to provide benefits for
competing uses exerts its force most heavily in the South. Concern for
the sustainability of resources and comparability of data across
regional lines factored into the USDA Forest Service's development of
the annual inventory system. Mandated by the Farm Bill of 1998, the
Forest Inventory and Analysis (FIA) nationwide program requires the
Forest Service to estimate and maintain current forest resources
information to provide real-time monitoring of forest ecosystems. The
Southern FIA program joins the Southern Research Station and the 13
Southern States' forestry associations in a strong partnership to survey
plots, manage data, perform statistical analyses, and publish reports.
*Compass* publications that address Forest Inventory and Analysis
include:

Bechtold, William A.; Zarnoch, Stanley J. 1999. **Field methods and data
processing techniques associated with mapped inventory plots.** In:
Aguirre-Bravo, Celedonio; Franco, Carlos Rodriguez, comp. North American
science Symposium: toward a unified framework for inventorying and
monitoring forest ecosystem resources. Proceedings RMRS-P-12. Fort
Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky
Mountain Research Station: 421-424. **(18)**

Brown, Mark J.; Sheffield, Raymond M. 2001. **Forest statistics for
North-central Alabama, 2000.** Resour. Bull. SRS-63. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station. 53
p. **(19)**

Brown, Mark J.; Smith, Greg M.; McCollum, Joseph. 2001. **Wetland forest
statistics for the South Atlantic States.** Resour. Bull. SRS-62.
Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern
Research Station. 52 p. **(20)**

Hartsell, Andrew J.; Vissage, John S. 2001. **Forest statistics for
North Alabama, 2000.** Resour. Bull. SRS-64. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station. 50
p. **(21)**

Johnson, Tony G., ed. 2001. **United States timber industry---an
assessment of timber product output and use, 1996**. Gen. Tech. Rep.
SRS-45. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. 145 p. **(22)**

**Looking at the Big Picture: the National Assessment and Projection of
Forest Resources**

You can get a copy of ***Forest Resources of the United States, 1997***
from the USDA Forest Service, North Central Research Station. Research
foresters W. Brad Smith, John L. Vissage, David R. Darr, and Raymond
Sheffield wrote this document, better known as the forest resources
section of the RPA Assessment. Highlights in the ***Forest Resources of
the United States, 1997*** include forest land area; timberland area;
timber inventories; mortality; growth and removals; removals; and
ownership and removals. The Forest and Rangeland Renewable Resources
Planning Act of 1974 (RPA) mandates the periodic assessment of our
Nation's resources managed by the Forest Service.

To request a print version of ***Forest Resources of the United States,
1997*** (GTR NC-219), call 608.231.9237 or send a message to
sparisi@fs.fed.us. Mail a written request to Forest Products Laboratory,
North Central Distribution Center, USDA Forest Service, One Gifford
Pinchot Drive, Madison, WI 53705. If you want to print or review the
document, visit <http://www.ncrs.fs.fed.us/pubs/gtr/gtr_nc219.pdf>.

Co-authors Smith and Darr work in the Forest Service's Washington
Office. Smith is with the Science, Policy, Information, and Inventory
Staff. Darr is a member of the Resource Valuation and Use Staff. Though
John Vissage was a Southern Station scientist for many years, the North
Central Station now claims him. Ray Sheffield leads the Resource
Analysis Unit of the Southern Station. The authors, all research
foresters, acknowledge the contributions of numerous team members who
made the ***Forest Resources of the United States, 1997*** such a
comprehensive document.

**On the Bookshelf**

**Valuing Wildlife in Southern Forests: Species, Habitat, Culture, and
Management**

James Dickson, Southern Research Station scientist emeritus, enlisted
the help of land managers, field experts, and research scientists to
assemble a wealth of knowledge about wildlife on southern forests.
***Wildlife of Southern Forests: Habitat and Management*** addresses the
history of the South's natural resources, forest types and physiographic
regions, plant and wildlife communities, and management options. The
chapters devoted to wildlife species cover the gamut: game species,
large carnivores, furbearers, and non-game communities. Contributors
provide details about species description, distribution and abundance,
population ecology, habitat use, and management. One chapter addresses
conflicts between wildlife and humans, and among humans pursuing their
wildlife interests. A second chapter discusses wildlife recreation
opportunities and preferences.

Two hundred and fifty-one color and black-and-white photos grace the
pages of **Wildlife of Southern Forests: Habitat and Management**. The
picture of the sandhill crane chick plopped on the ground beside an egg
calls for action---you want to help that other little one whose
still-encased beak barely pokes out! **Wildlife of Southern Forests:
Habitat and Management** includes lists of common and scientific names
for the animals and plants in the text, and an index helps guide you. To
purchase a copy for \$50, visit
[http://www.hancockhouse.com](http://www.hancockhouse.com/), send an
e-mail to <sales@hancockhouse.com>, or call

800.938.1114.

**Station News**

**Susan Fox** joins the SRS Leadership Team as assistant director for
planning and applications. Susan's position includes working with policy
and budget leaders in the Forest Service. The responsibility for
scientific staff work essential to the long-range planning and
application of the Southern Station's multifunctional resource programs
rests with Susan. As assistant director for planning and applications,
Susan works with policy and budget leaders in the Forest Service. Her
position links her closely to research unit project leaders. Susan's
scientific credentials complement her field experience and management
skills.

Susan began working in forestry in 1977 in Sewanee, TN, assisting in a
soils research project with the USDA Forest Service research work unit.
She earned her B.S. degree in forestry from the University of the South.
She received her M.S. in forestry from the Albert-Ludwigs University in
Freiburg, Germany. While living in Germany, Susan worked in a wide range
of jobs, planting and felling trees, conducting forest inventory and
marking timber, laying out roads, and conducting deer browse surveys.
Susan began her Forest Service career in 1985, as a research assistant
to the spruce-fir forest research cooperative in Broomall, PA. She spent
three years establishing a quality assurance program as a part of the
multi-agency acid rain research program. From 1988 until 1997 she served
first as deputy program manager and then as program manager for the
Southern Commercial Forest Research Cooperative that shifted focus into
the Southern Global Change Program. For the past five years, Susan
pursued graduate studies at Duke University and completed a study of
long-term effects of agriculture on Southern Piedmont forest soils.
Welcome, Susan!

**Clark Baldwin, Jr.**, a research forester with the Southern Research
Station and the former Southern Forest Experiment Station, joined the
Forest Service's Washington Office as lead silviculturist. Clark served
as section head of Information Management for the Southern Station's
Forest Inventory and Analysis research unit. He conducted research in
Pineville, LA as a member of the Ecology and Management of Even-aged
Southern Pine Forests unit. Clark's research produced Forest Service
"best sellers" over the years. His focus includes modeling growth and
yield of pine trees and stands; understanding and modeling trees and
stand structure, especially crown structure in pine stands; linking a
process model (MAESTRO) and a growth and yield model (PTAEDA2); and wood
quality in managed pine stands. Two of Clark's most recent publications
appear in this issue of *Compass*:

Leduc, Daniel J.; Matney, Thomas G.; Belli,

Keith L.; Baldwin, V. Clark, Jr. 2001. **Predicting diameter
distributions of longleaf pine plantations: a comparison between
artificial neural networks and other accepted methodologies.** Res.Pap.
SRS-25. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. Asheville, NC. 18 p. **(2)**

Newbold, Ray A.; Baldwin, V. Clark, Jr.; Hill, Gary. 2001. **Weight and
volume determination for planted loblolly pine in North Louisiana.**
Res. Pap. SRS-26. Asheville, NC: U.S. Department of Agriculture, Forest
Service, Southern Research Station. 19 p. **(4)**

**Southern Pines Research**

Johnsen, K.H.; Butnor, J.R.; Maier, C.; and others. 2001.
**Fertilization increases below-ground carbon sequestration of loblolly
pine plantations.** In: Proceedings: First national conference on carbon
sequestration \[CD-ROM\]. \[Place of publication unknown\].
<http://www.netl.doe.gov/publicatins/proceedings/01/carbon_seq/carbon_seq01.html>.
\[Date accessed unknown\].

The extent of fertilization of southern pine forests is increasing
rapidly; industrial fertilization increased from 16,200 ha per year in
1988, to 344,250 ha in 1998. Fertilization increases stand productivity
and can increase carbon (C) sequestration by: (1) increasing
above-ground standing C; (2) increasing C stored in forest products; and
(3) increasing below-ground C pools. This talk will concentrate on the
latter and will present summary data from five experiments spatially
ranging from the Virginia Piedmont to the Alabama Coastal Plain, and
ranging in age from one to 17 years. Fertilization has increased pine
growth in all of these studies. In two other studies, fertilization has
significantly decreased C losses from the soil as measured via an
automated CO~2~ efflux system using an infrared gas analyzer. In two
more of these studies, soil CO~2~ efflux did not differ significantly
between control and fertilized plots (means under fertilization were
lower though), although below-ground biomass was increased. And in the
last study, fertilization increased soil CO~2~ efflux by approximately
18 percent; however, fertilization increased below-ground biomass by
more than 250 percent. Combined, these studies indicate forest
fertilization increases below-ground C sequestration. As forest industry
is firmly established in the Southeastern United States, and since soil
nutrition is a major limiting factor to tree growth, increasing forest
fertilization represents a realistic method to sequester atmospheric C
in the short- to long-term. **(1)**

Leduc, Daniel J.; Matney, Thomas G.; Belli, Keith L.; Baldwin, V. Clark,
Jr. 2001. **Predicting diameter distributions of longleaf pine
plantations: a comparison between artificial neural networks and other
accepted methodologies.** Res.Pap. SRS-25. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station.
Asheville, NC. 18 p.

Artificial neural networks (NN) are becoming a popular estimation tool.
Because they require no assumptions about the form of a fitting
function, they can free the modeler from reliance on parametric
approximating functions that may or may not satisfactorily fit the
observed data. To date there have been few applications in forestry
science, but as better NN software and fitting algorithms become
available, they may be used to solve a wide variety of
problems---particularly problems where the underlying relationship
between predicted and predictors is unknown. We benchmark tested an
alternative to the traditional Weibulll probability distribution
function, diameter-at-breast-height moment, and direct parameter
prediction models for approximating stand-diameter distributions. Using
a feedforward backpropagation network, we demonstrated that NN are a
somewhat better option. Unlike Weibull approximations, NN solutions
cannot easily be mathematically constrained to match known reality
constraints, but this difficulty is easy to overcome in practice.
**(2)**

Maier, Chris A. 2001. **Stem growth and respiration in loblolly pine
plantations differing in soil resource availability.** Tree Physiology.
21: 1183-1193.

Stem respiration and growth in 10‑year‑old loblolly pine (*Pinus taeda*
L.) plantations were measured monthly during the third year of
fertilization and irrigation treatments to determine whether soil
resource availability differentially altered growth and respiration in
stem tissue. Fertilized trees had significantly greater stem biomass,
stem nitrogen concentration (\[N\]) and growth rate than unfertilized
trees. Stem respiration (*R*~t~) was significantly greater in fertilized
trees when expressed on a per unit surface area (*R*~t,a~, μmol
CO~2~m^‑2^s^‑1^), sapwood volume (*R*~t,v~, μmol CO~2~m^‑3^s^‑1)^ ), or
mass *(R*~t,w~,nmol CO~2~g^‑1^s^‑1)^) basis; however, there was no
difference between treatments when expressed as a function of stem N
content (*R*~t,n~, μmol CO~2~(molN)^‑1^s^‑1)^). Irrigation had no
significant effect on R~t~, or annual stem growth. Daily total
respiration (R~d~, mol CO~2~ m^-2^ day^-1^) and stem diameter growth
both had a seasonal bimodal pattern with peaks in early spring and
midsummer. Stem \[N\] declined significantly during the growing season.
Stem growth rate and \[N\] explained 75 percent of the seasonal
variation in temperature‑normalized *R*~t,a~.

The mature tissue method was used to partition total stem respiration
(*R*~t~) into maintenance (*R*~m~) and growth (*R*~g~) components. There
was a linear correlation between winter *R*~t,v~, a measure of basal
*R*~m~, and sapwood N content; however, *R*~t,v~ per unit N was greater
in January before diameter growth started than in the following December
after growth ceased, indicating that *R*~t,v~ declined as stem diameter
increased. Consequently, estimates of annual maintenance respiration
(*R*~M~) based on January data were 44 percent higher than estimates
based on December data. Growth respiration was correlated with stem
growth rate (*r*^2^ = 0.55). The growth respiration coefficient
(*r*~g~)---the slope of the relationship between *R*~g~ and stem growth
rate---was 0.24. Respiration accounted for 37 percent of annual stem
carbon budget. Stem carbon‑use efficiency (CUE)---the ratio of stem
growth to stem growth plus respiration---averaged 0.63 and was
unaffected by fertilization. **(3)**

Newbold, Ray A.; Baldwin, V. Clark, Jr.; Hill, Gary. 2001. **Weight and
volume determination for planted loblolly pine in North Louisiana.**
Res. Pap. SRS-26. Asheville, NC: U.S. Department of Agriculture, Forest
Service, Southern Research Station. 19 p.

The objective of this study was to assess the variability in
weight-to-volume relationships in loblolly pine (*Pinus taeda* L.)
plantations and to determine predictability based on stand age, site
quality, and/or tree size. Tree ages ranged from 11 to 40 years, with
diameters to 21 inches and heights to 91 feet. Measured site indices
ranged from 45 to 72 at base age 25. A total of 75 planted loblolly pine
trees were felled and processed to assess the variability in bole weight
to volume relationships. Cubic volume, green weight, and dry weight
relationships were investigated; and the predictability of these
variables with respect to age, site index, and tree size was determined.
**(4)**

Saenz, Daniel; Conner, Richard N.; Rudolph, D. Craig; Eengstrom, R.
Todd. 2001. **Is a "hands-off" approach appropriate for red-cockaded
woodpecker conservation in twenty-first century landscapes?** Wildlife
Society Bulletin. 29(3): 956-966.

The endangered red‑cockaded woodpecker *(Picoides borealis) is* well
adapted to fire-maintained pine ecosystems of the Southeastern United
States. Management practices vary greatly among land ownerships. In some
wilderness areas and state parks, a \"no management\" policy has
eliminated use of prescribed fire, artificial cavities, and woodpecker
translocation, tools that have proved effective elsewhere in recovering
woodpecker populations. We compared forests with essentially \"no
management\" to actively managed forests of similar tree ages and
similar red‑cockaded woodpecker population demographics. We also
compared sites that had received no management in the past to the same
sites after management. In every case, populations in forests that did
not use state‑of‑the‑art management for woodpeckers declined severely
compared to those in managed forests. Because managed forests typically
used all available management techniques concurrently, it was not
possible to separate and rank effectiveness of specific management
activities. One exception was the Wade Tract in Georgia, where
prescribed fire was the primary activity for herbaceous layer and
hardwood management in a high‑density, stable woodpecker population.
Wilderness areas, which are intended to be pristine places that preserve
biodiversity, are losing red‑cockaded woodpeckers, a keystone species in
the ecosystem, at an alarming rate. Collectively, 9 groups of
red‑cockaded woodpeckers were present in 4 wilderness areas in Texas
national forests in 1983. At the close of the millennium, only one
woodpecker group remained and its continued existence is unlikely
without management. The very fragmented features of present‑day
landscapes and intervention by humans impair the effectiveness of
natural disturbance processes, primarily growing‑season fire, that
historically produced and maintained open pine savannas with grass‑forb
herbaceous layers in the pre‑Columbian forests of the southeastern U.S.;
therefore, active management must be used if the red‑cockaded woodpecker
is to persist. **(5)**

Sanchez, Felipe G. 2001. **Loblolly pine needle decomposition and
nutrient dynamics as affected by irrigation, fertilization, and
substrate quality.** Forest Ecology and Management. 152: 85-96.

This study examined the effects of initial litter quality and irrigation
and fertilization treatments on litter decomposition rates and nutrient
dynamics (N, Ca, K, Mg, and P) of loblolly (*Pinus* *taeda* L.) pine
needles in the North Carolina Sand Hills over 3 years. Litter quality
was based on the initial C/N ratios, with the high‑quality litter having
a significantly (*P* \< 0.001) lower C/N ratio (143 ± 2.5) compared with
the low quality litter (172 ± 1.3). Initial litter quality and the
irrigation treatment did not significantly affect decomposition rates
but the fertilization treatment effects were significant. Low quality
needles on fertilized plots had higher decomposition rates *(k = 0*.36 ±
0.01 year 1 for the fertilized and irrigated + fertilized plots) than on
unfertilized plots *(k =* 0.26 ± 0.01 and 0.28 ± 0.01 year^-1^ for the
control and irrigated plots, respectively). The decomposing litter was a
net sink for P and N and a net source of Mg, Ca, and especially K.
Whereas initial substrate quality did not affect decomposition rates, it
did affect the rate of release. Compared to the low quality litter, the
high quality litter released K at a higher rate, released Mg at a lower
rate, and accumulated N at a higher rate. Fertilization decreased the
rate of release of Mg and K in high‑quality litter and Mg and Ca in low
quality litter. In addition, fertilization increased the rate of
accumulation of P in both. **(6)**

Schmidtling, R.C. 2001. **Southern pine seed sources.** Gen. Tech. Rep.
SRS-44. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. Asheville, NC. 25 p.

The selection of an appropriate seed source is critical for successful
southern pine plantations. Guidelines for selection of seed sources are
presented for loblolly (*Pinus taeda* L.) slash (*P. elliottii*
Engelm.), longleaf (*P. palustris* Mill., Virginia (*P. virginiana*
Mill.), shortleaf (*P. echinata* Mill.), and sand \[*P. clausa* (Chapm.
ex Engelm.) Vasey ex Sarg.\] pines. Seed movement guidelines in this
handbook are based on climatic similarities between the seed source
origin and the planting site. Because yearly average minimum temperature
is the most important climatic variable related to growth and survival,
it has been used to define the rules of seed movement. This variable,
which defines plant hardiness zones, has been used for many years by
horticulturists to guide the transfer of plant materials. East-west
movement to areas of similar climate is permissible, with the exception
of loblolly pine. **(7)**

Strom, B.L.; Goyer, R.A. 2001. **Effect of silhouette color on trap
catches of *Dendroctonus frontalis* (Coleoptera: Scolytidae).** Annals
of the Entomological Society of America. 94(6): 948-953.

With the exception of responses to semiochemicals, host selection
behaviors of *D. frontalis* are largely unstudied. To better understand
the host finding behavior of *D. frontalis*, and to identify potential
visual disruptants, we evaluated the response of *D. frontalis* to
multiple-funnel traps of eight different colors. Multiple-funnel traps
provide an attractive vertical silhouette, similar to a host stem, that
aids in capturing bark beetles and allows for controlled evaluation of
visual cues. Evaluation of mean trap catch of each color by analysis of
variance (ANOVA)produced two separate groups: white and yellow traps
caught significantly fewer *D. frontalis* than the other six colors
tested (black, blue, brown, gray, green, red). Examination of spectral
reflectance curves showed that the eight colors could be naturally
placed into two groups, those with high peak reflectance (white and
yellow) and those with low peak reflectance (black, blue, brown, gray,
green, red). When high and low peak reflectance were substituted for
color in a separate ANOVA, reflectance group was as good as color at
explaining the variability in trap catch (*r*^2^ = 0.88 versus 0.92).
Therefore, hue (dominant wavelength) was unimportant in affecting *D.
frontalis* host finding behavior at the reflectance levels we tested
and, thus, we found no strong evidence that differential wavelength
sensitivity affected the response of *D. frontalis*. These results show
that dark colored silhouettes (those with low reflectance values),
regardless of hue, are best for capturing *D. frontalis*, while white or
yellow are the best candidate colors for disrupting host finding.
**(8)**

Waldrop, Thomas A.; Welch, Nicole Turrill; Brose, Patrick H.; and
others. 2000. **Current research on restoring ridgetop pine communities
with stand replacement fire.** In: Yaussy, Daniel A., comp. Proceedings:
workshop on fire, people, and the central hardwoods landscape; 2000
March 12-14; Richmond, KY. Gen. Tech. Rep. NE-274. Newton Square, PA:
U.S. Department of Agriculture, Forest Service, Northeastern Research
Station: 103-109.

Ridgetop pine communities of the Southern Appalachian Mountains
historically have been maintained by lightning- and human-caused fires.
With fire suppression for several decades, characteristic stands are
entering later seral stages. They typically have an overstory of Table
Mountain (*Pinus pungens*)and/or pitch pine (*P. rigida*), a midstory of
chestnut oak (*Quercus prinus*), scarlet oak (*Q. coccinea*), and
blackgum (*Nyssa sylvatica*), and a shrub layer of dense mountain laurel
(*Kalmia latifolia*). Previous research suggests that restoration of
these communities can be accomplished with the high-intensity fires that
open the forest canopy and expose mineral soil. Three recent studies
examined plant-community response to high-intensity prescribed fires. A
series of corollary studies help to explain some of the results of these
field studies. High and medium-high intensity fires provided adequate
sunlight for pines seedlings, whereas medium-low and low intensity fires
did not. Post-burn duff was deep and did not vary by fire intensity. We
observed sufficient seedling densities to restore pine-dominated stands
after all but the highest intensity fires. Many seedlings survived the
first growing season as their roots penetrated duff to reach mineral
soil. Hardwood rootstocks resprouted on sites treated with all fire
intensities and may outcompete pine seedlings for available resources.
High-intensity fires may have reduced mycorrhizal abundance and moisture
availability for new germinants. Fires of lower intensity than
previously recommended or multiple fires of very low-intensity may best
provide conditions for pine regeneration, but additional research is
needed. **(9)**

**Wetlands, Bottomland Hardwoods, and Streams Research**

Allen, J.A.; Keeland, B.D.; Stanturf, J.A.; and others. 2001. **A guide
to bottomland hardwood restoration.** U.S. Geological Survey, Biological
Resources Division Information and Technology Report
USGS/BRD/ITR--2000-0011; Gen. Tech. Rep. SRS-40. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station.
Asheville, NC. 132 p.

During the last century, a large amount of the original bottomland
hardwood forest area in the United States has been lost, with losses
greatest in the Lower Mississippi Alluvial Valley and East Texas. With a
holistic approach in mind, this manual describes methods to restore
bottomland hardwoods in the lower Midwest, including

The Lower Mississippi Alluvial Valley and the Southeastern United
States. Bottomland hardwoods in this guide include not only the hardwood
species that predominate in most forested floodplains of the area, but
also

the softwood species such as baldcypress that often co-occur. General
restoration planning considerations are discussed, as well as more
specific elements of bottomland hardwood restoration, such as species
selection, site preparation, direct seeding, planting of seedlings, and
alternative options for revegetation. We recognize that

most projects will probably fall more within the realm of reforestation
or afforestation rather than a restoration, as some site preparation and
the planting of seeds or trees may be the only actions taken. Practical
information needed to restore an area is provided in the guide, and it
is left up to the restorationist to decide how complete the restoration
will be. Postplanting and monitoring considerations are also addressed.
Restoration and management of existing forests are included because of
the extensive areas of degraded natural forests in need of
rehabilitation. **(10)**

Conner, William H.; Hill, Nicole L.; Whitehead, Evander M.; and others.
2001. **Forested wetlands of the Southern United States: a
bibliography.** Gen. Tech. Rep. SRS-43. Asheville, NC: U.S. Department
of Agriculture, Forest Service, Southern Research Station. 133 p.

The term forested wetland covers a variety of forest types, including
mangroves, cypress/tupelo swamps, bottomland hardwoods, pocosins and
Carolina bays, flatwoods, and mountain fens. These forests are dominated
by woody species that have morphological features, physiological
adaptations, and/or reproductive strategies enabling them to achieve
maturity and reproduce in an environment where the soils within the
rooting zone may be inundated or saturated for various periods during
the growing season. Although alluvial floodplains occur along most
streams of the United States, they are most extensive in the Atlantic
Coastal Plain, Gulf Coastal Plain, and Mississippi Alluvial Plain. Only
about half of the original floodplain forests remained by the 1930s, and
conversion to agriculture continued at an accelerated pace during the
1960s and 1970s. The purpose of this bibliography is to provide a
detailed listing of references for students and researchers of the
varied studies conducted in these forest types. **(11)**

Goelz, J.C.G.; Meadows, J.S.; Fristoe, T.C. 2001. **Development of water
tupelo coppice stands on the Mobile-Tensaw River delta for five years
after precommercial thinning and cleaning.** Southern Journal of Applied
Forestry. 25(4): 165-172.

Three 4-yr-old stands (or locations) were selected for treatment.
Treatment consisted of two components: (1) thinning water tupelo (*Nyssa
aquatica* L.) stump sprouts and (2) cutting all stems of Carolina ash
(*Fraxinus caroliniana* Mill.) and black willow (*Salix nigra* Marsh.)
(cleaning). Contrary to results in other areas, survival of water tupelo
coppice was very high and was not affected by the treatments. Cleaning
had little or no positive effect on the individual tree or stand-level
variables we measured. Thinning sprout clumps significantly increased
diameter growth of water tupelo; the effect of thinning was considerably
larger for one location. Stand basal area growth was decreased by
thinning sprout clumps. However, quadratic mean diameter was increased
by thinning, particularly at one location. Although thinning decreased
basal area 5 yr after treatment, the increase in quadratic mean diameter
was sufficient for there to be no significant effect of thinning on
total volume 5 yr after treatment. Because of this, and in anticipation
of imminent natural thinning of the unthinned plots, we suspect that the
thinned plots will eventually have significantly greater standing volume
than the unthinned plots, at least for the location where density of
large sprouts was initially the highest. Rotation age will be decreased
for that stand because stems will achieve merchantable size sooner. Thus
we consider precommercial thinning of sprout clumps to be a potentially
effective practice in stands with a high density of large water tupelo
sprouts. **(12)**

Meadows, James S.; Burkhardt, E.C.; Johnson, Robert L.; Hodges, John D.
2001. **A numerical rating system for crown classes of southern
hardwoods.** Southern Journal of Applied Forestry. 25(4): 154-158.

A numerical rating system to delineate crown classes of southern
hardwoods is described. The system is based on four criteria: (1) amount
of direct sunlight from above, (2) amount of direct sunlight from the
sides, (3) crown balance, and (4) relative crown size. The total point
value assigned places the tree within one of the four crown classes. The
rating system can be used to train inexperienced hardwood foresters and

should give experienced foresters a better grasp of those factors
important in hardwood crown classification. Time required to evaluate a
tree varies by tree, by stand conditions, and by observer, but
experienced users of the system can easily rate most trees in 30‑45
seconds. The rating system is particularly useful in situations where an
individual tree appears to be borderline between two crown classes. For
researchers, the system provides: (1) an expression of individual‑tree
crown characteristics, and (2) documentation of changes in crown
position and condition. In two tests comparing the numerical rating
system with the conventional crown classification system, use of the
rating system consistently improved the ability of participants to
correctly identify crown classes. Dominant and suppressed trees were the
easiest to assess with the numerical rating system, whereas codominant
and intermediate trees were the most difficult. Agreement between
participants and experts in identification of crown classes increased
with the level of the participants\' forestry knowledge and experience.
In one test, a group of participants attending a continuing‑education
hardwood short course,

but with little to moderate hardwood experience, correctly identified
the crown class of 78 percent of the trees after

only one hour of training. **(13)**

Trettin, C.C.; Song, B.; Jurgensen, M.F.; Li, C. 2001. **Existing soil
carbon models do not apply to forested wetlands**. Gen. Tech. Rep.
SRS-46. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. 10 p.

When assessing the biological, geological, and chemical cycling of
nutrients and elements---or when assessing carbon dynamics with respect
to global change---modeling and simulation are necessary. Although
wetlands occupy a relatively small proportion of Earth's terrestrial
surface (\< 3 percent), they contain a disproportionate share of the
terrestrial carbon pool (15 to 22 percent). Models that do not
accurately represent wetland soil processes cannot, therefore, provide
reasonable simulations. We evaluated 12 widely used soil C models to
determine their applicability to wetland ecosystems: CANDY, CENTURY,
DAISY, DNDC, ITE, MBL-GEM, NCSOIL, QSOIL, ROTHC, SOMM, VVV, and WMEM.
Only three (CENTURY, DNDC, and WMEM) allow for anaerobic conditions;
none contains components for anoxia, ground water hydrology, multiple
organic and physical soil layers, or a daily time-step, all of which are
necessary when modeling soil C in wet soils. Accordingly, for any land
area that includes wetlands, none of the individual models would produce
reasonable simulations based on soil process. We present a wetland soil
C model framework based on desired attributes, the DNDC model, and
components of the CENTURY and WMEM models. Our proposed synthesis would
be appropriate when considering soil C dynamics at multiple spatial
scales and where the land area considered includes both wetland and
upland ecosystems. **(14)**

**Southern Appalachians Research**

Greenberg, Cathryn H.; Lanham, J. Drew. 2001. **Breeding bird
assemblages of hurricane-created gaps and adjacent closed canopy forest
in the Southern Appalachians.** Forest Ecology and Management. 154:
251-260.

We studied breeding bird assemblages in forest gaps created in 1995 by
Hurricane Opal at the Bent Creek Experimental Forest in Asheville, NC.
We hypothesized that forest gaps and adjacent closed‑canopy forest would
differ in bird density, richness, diversity, and relative abundances of
some species. To test this hypothesis we censused breeding bird
assemblages for 2 years in 12 gaps (0.1‑1.2 ha) and 12 adjacent closed
canopy controls using strip transects. Gaps had more coarse woody
debris, shrub cover, brush piles, and pit and mound microtopography than
controls. Canopy cover was lower in gaps than controls, but remained
high (69.4 ± 2.1 percent versus 89.6 ± 1.7 percent). Bird assemblage
similarity was high. Total density and species richness of birds were
higher in gaps than in controls, but species diversity did not differ
between treatments. Shrub (primarily Carolina Wrens) and bark‑foragers,
and cavity shrub and canopy‑nesters were more abundant in gaps than in
controls. Densities of gap‑associated (indigo bunting, hooded warbler,
Carolina wren) and edge (eastern towhee) species were more abundant in
gaps. Abundance of interior species including red‑eyed vireo and scarlet
tanager were about equal in gaps and controls. Only Ovenbirds were more
abundant in controls than gaps. Species that require larger patches of
young second‑growth forest, such as prairie warbler, and yellow‑breasted
chat, did not occur in gaps; but neither are they abundant in the
Asheville basin. No brown‑headed cowbirds were observed in gaps or
controls. Unpublished data indicate that parasitism of artificial ground
nests did not occur, and predation rates did not differ between gaps and
controls. Juvenile birds and other evidence of breeding were observed
more often in gaps than in controls, suggesting that gaps attract bird
families for foraging and provide microsites that attract breeding
pairs. Gap size was positively correlated with bird density, species
richness, and diversity. This study suggests that small openings and
interior edge habitat created by treefall gaps within a forested matrix
do not adversely affect breeding birds as measured by the abundance of
individual species or community indices. We suggest that canopy gaps
increase avian diversity at a landscape scale by providing habitat
patches for some species that require young, second‑growth forest, and
serve as magnets for recruitment and foraging. **(15)**

###### **Interior Highlands Research**

Burr, Brooks M.; Adams, Ginny L.; Krejca, Jean K.; and others. 2001.
**Troglomorphic sculpins of the *Cottus carolinae* species group in
Perry County, Missouri: distribution, external morphology, and
conservation status.** Environmental Biology of Fishes. 62: 279-296.
\[Editor's note: Southern Research Station scientist Melvin L. Warren,
Jr. co-authored this publication.\]

The existence of cavernicolous sculpin (here allocated to *Cottus
carolinae,* banded sculpin, and referred to as grotto sculpin), in the
karst regions of Perry County, MO, first came to our attention in 1991.
Examination of 35 caves in Missouri, 96 in Illinois, 17 in Tennessee, 2
in Indiana, and 11 in Arkansas revealed that banded sculpin are common
in cave habitats; however, grotto sculpin are limited to two karst areas
of Perry County, MO, where they are known from only six cave systems.
These caves and their streams are extensive and apparently provide a
unique habitat compared to other karst systems; this may be a critical
factor in the present restricted distribution of the grotto sculpin.
Grotto sculpin occupy pools and riffles of cave streams, and occur over
a variety of substrates, from sediment to breakdown. Density estimates
in Mystery and Running Bull caves were 0.29 and 0.63 individuals m^‑2^,
respectively. Grotto sculpin have small eyes (1‑6 percent SL vs. 6‑10
percent SL in epigean samples), significantly reduced pigmentation
(including nearly complete loss of dorsal saddles), a reduction in
pelvic fin ray number (from 4 + 4 elements to often 4 + 3, or 3 + 3),
and enlarged cephalic lateralis pores (e.g., mandibular pores of
cavernicolous samples are 2‑3 times those of epigean stream samples).
Multivariate analyses of body shape revealed statistically significant
separation of epigean and hypogean samples, with eye size highly
variable, but smallest in the Running Bull Cave population. We interpret
these results as representative of losses associated with long‑term cave
habitation. Caves of Perry County provide ample habitat for grotto
sculpin, but because the caves are located downgradient of the city of
Perryville and an intensively farmed landscape, point and non‑point
source pollution threaten their continued existence. Escape of farm‑pond
fishes through the extensive sinkhole network in Perry County has
increased potential predation pressure on grotto sculpin by channel
catfish, *Ictalurus punctatus,* and other species normally excluded from
cave environments. **(16)**

###### **Large Scale Assessment and Modeling Research**

Yuancai, Lei; Parresol, Bernard R. 2001. **Remarks on height-diameter
modeling.** Res. Note SRS-10. Asheville, NC: U.S. Department of
Agriculture, Forest Service, Southern Research Station. 5 p.

Height-diameter model forms in earlier published papers are examined.
The selection criteria used in height-diameter model forms are not
reasonable when considering tree biological growth pattern. During model
selection, forms for height-diameter relationships should include
consideration of both data-related and reasonable biological criteria,
not just data-related criteria. A reasonable model form should possess
the S-shaped functional properties of monotonic increment (*dy/dt* \>
0), inflection point (*d^2^y/dt^2^* = 0), and asymptotical value
(*y*→asymptote as *t*→∞), rather than the concave shaped, functional
properties. The S-shaped models are best when appropriate data are
collected (data sets containing early growth). The Bertalanffy-Richards
and Schnute functions are recommended for modeling height-diameter
relationships, and an example contrasts the fit of the sigmoidal Schnute
function against the concave Meyer function. **(17)**

###### **Inventory and Monitoring Research**

Bechtold, William A.; Zarnoch, Stanley J. 1999. **Field methods and data
processing techniques associated with mapped inventory plots.** In:
Aguirre-Bravo, Celedonio; Franco, Carlos Rodriguez, comp. North American
science Symposium: toward a unified framework for inventorying and
monitoring forest ecosystem resources; 1998 November 2-6; Guadalajara,
Mexico. Proceedings RMRS-P-12. Fort Collins, CO: U.S. Department of
Agriculture, Forest Service, Rocky Mountain Research Station: 421-424.

The U.S. Forest Inventory and Analysis (FIA) and Forest Health
Monitoring (FHM) programs utilize a fixed‑area mapped‑plot design as the
national standard for extensive forest inventories. The mapped‑plot
design is explained, as well as the rationale for its selection as the
national standard. Ratio‑of‑means estimators are presented as a method
to process data from mapped inventory plots.

It is particularly timely that we have convened to develop a sampling
framework for forest ecosystems that is unified across the entire North
American continent. In the United States we have been engaged in a
similar effort to standardize our inventory system for the past decade.
The purpose of this paper is to describe the sampling design implemented
nationally in the United States, provide background information about
how this design evolved, explain how the resulting data can be
processed, and describe our experience with this design since its
implementation in 1991. **(18)**

Brown, Mark J.; Sheffield, Raymond M. 2001. **Forest statistics for
North-central Alabama, 2000.** Resour. Bull. SRS-63. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station. 53
p.

This report summarizes a 2000 inventory of the forest resources of a
15-county area of Alabama. Major findings are highlighted in text and
graphics; detailed data are presented in 49 tables. **(19)**

Brown, Mark J.; Smith, Greg M.; McCollum, Joseph. 2001. **Wetland forest
statistics for the South Atlantic States.** Resour. Bull. SRS-62.
Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern
Research Station. 52 p.

Twenty-one percent, or 17.6 million acres, of the timberland in the
South Atlantic States was classified as wetland timberland. Sixty
percent of the region's wetland timberland was under nonindustrial
private forest ownership. Forty-eight percent of the region's wetland
timberland was classified as sawtimber-sized stands. Lowland hardwood
types made up 62 percent of the wetland timberland. Thirty-one percent
of the wetland timberland occurred on a flatwoods physiography. Wetland
timberland contained 30 billion cubic feet of growing-stock volume, 24
percent of the region's total. Removals from wetland timberland averaged
842 million cubic feet, 20 percent of the region's total. The two
greatest impacts to wetland timberland were natural disturbance and
final harvest, which averaged 375 and 295 thousands annually,
respectively. **(20)**

Hartsell, Andrew J.; Vissage, John S. 2001. **Forest statistics for
North Alabama, 2000.** Resour. Bull. SRS-64. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station. 50
p.

This report summarizes a 2000 inventory of a 10-county area of Alabama.
Major findings are highlighted in text and graphics; detailed data are
presented in 49 tables. **(21)**

Johnson, Tony G., ed. 2001. **United States timber industry---an
assessment of timber product output and use, 1996**. Gen. Tech. Rep.
SRS-45. Asheville, NC: U.S. Department of Agriculture, Forest Service,
Southern Research Station. 145 p.

This report is a compilation of timber product output for the United
States and the five Resources Planning Act regions for 1996, and is a
companion report to the Forest Resources of the United States, 1997.
Roundwood output from the Nation's forest totaled 16.4 billion cubic
feet, 8 percent less than in 1991. Saw logs were the leading roundwood
product at 7.1 billion cubic feet; pulpwood ranked second at 5.2 billion
cubic feet; and veneer logs were third at 1.3 billion cubic feet. The
South supplied 58 percent of the Nation's timber product output and had
7 of the top 10 producing States. Softwood species accounted for 61
percent of output, and nonindustrial private forest owners supplied 60
percent of the Nation's roundwood products. Mill byproducts generated
from primary manufacturers totaled 6.1 billion cubic feet. Only 2
percent of the mill residues were not used. Mill residue was used
primarily for fuel and fiber products. **(22)**

###### **Foundation Programs Research**

Butnor, J.R.; Doolittle, J.A.; Kress, L.; and others. 2001. **Use of
ground-penetrating radar to study tree roots in the Southeastern United
States.** Tree Physiology. 21: 1269-1278. \[Editor's Note: Southern
Research Station scientist Kurt Johnsen co-authored this publication.\]

The objectives of our study were to assess the feasibility of using
ground‑penetrating radar (GPR) to study roots over a broad range of soil
conditions in the Southeastern United States. Study sites were located
in the Southern Piedmont, Carolina Sandhills and Atlantic Coast
Flatwoods. At each site, we tested for selection of the appropriate
antenna (400 MHz versus 1.5 GHz), determined the ability of GPR to
resolve roots and buried organic debris, assessed root size, estimated
root biomass, and gauged the practicality of using GPR. Resolution of
roots was best in sandy, excessively drained soils, whereas soils with
high soil water and clay contents seriously degraded resolution and
observation depth. In the Carolina Sandhills, 161 x 1‑m plots were
scanned with the 1.5 GHz antenna using overlapping grids. Plots were
subsequently excavated, larger roots (\> 0.5 cm diameter) sketched on
graph paper before removal, and all roots oven‑dried, classified by
size, and weighed. Roots as small as 0.5 cm in diameter were detected
with GPR. We were able to size roots (0.5 to 6.5 cm in diameter) that
were oriented perpendicular to the radar sweep *(r*^2^ *=* 0.81, *P* =
0.0004). Use of image analysis software to relate the magnitude of radar
parabolas to actual root biomass resulted in significant correlations
*(r*^2^ = 0.55, *P* = 0.0274). Orientation and geometry of the
reflective surface seemed to have a greater influence on parabola
dimensions than did root size. We conclude that the utility of current
GPR technology for estimating root biomass is site‑specific, and that
GPR is ineffective in soils with high clay or water content and at sites
with rough terrain (most forests). Under particular soil and site
conditions, GPR appears to be useful for augmenting traditional biomass
sampling. **(23)**

Butry, David T.; Mercer, D. Evan; Prestemon, Jeffrey P.; and others.
2001. **What is the price of catastrophic wildfire?** Journal of
Forestry. (99)11: 9-17.

We modeled and analyzed the economic impacts of the six weeks of large,
catastrophic wildfires in northeastern Florida in June and July 1998,
among Florida's most devastating in recent history. The result of the
unusually strong El Nino--Southern Oscillation (ENSO) in 1998, the
Florida wildfires produced economic impacts of at least \$600 million,
similar in scale to recent category-2 hurricanes. Improved understanding
of the interactions between management, wildfire, and its costs may
yield large payoffs to society by identifying optimal intervention
activities. **(24)**

Fonseca, Teresa J.F.; Parresol, Bernard R. 2001. **A new model for cork
weight estimation in Northern Portugal with methodology for construction
of confidence intervals.** Forest Ecology and Management. 152: 131-139.

Cork, a unique biological material, is a highly valued non‑timber forest
product. Portugal is the leading producer of cork with 52 percent of the
world production. Tree cork weight models have been developed for
Southern Portugal, but there are no representative published models for
Northern Portugal. Because cork trees may have a different form between
Northern and Southern Portugal, equations developed with southern data
do not always predict well in the North. An analysis of eight tree
variables revealed the interaction between tree circumference (outside
bark at 1.3 m) (CSC) and debarking height (*H*~DEB~) to be the best
predictor variable. A nonlinear exponential function was chosen over a
simple linear function due to a slight curvature exhibited in the plot
of weight over CSC × *H*~DEB~. The paper concludes with a section on
construction and use of confidence intervals about the mean and
individual predictions from the nonlinear regression, plus a method to
place bounds on an aggregate estimate for a stand. **(25)**

Haines, Terry K.; Busby, Rodney L.; Cleaves, David A. 2001. **Prescribed
burning in the South: trends, purpose, and barriers.** Southern Journal
of Applied Forestry. 25(4): 149-153.

The results of a survey of fire management officials concerning
historical and projected prescribed burning activity in the South are
reported. Prescribed burning programs on USDA Forest Service and private
and State-owned lands are described in terms of area burned by ownership
and State, intended resource benefits, barriers to expanded burning, and
optimum burning area needed to achieve resource management goals. More
than 4.1 million ac/yr of pine-type forest were burned between 1985 and
1994, about 6.5 percent of the area in pine-type forest per year.
**(26)**

Hunter, William C.; Buehler, David A.; Canterbury, Ronald A.; and
others. 2001. **Conservation of disturbance-dependent birds in eastern
North America.** Wildlife Society Bulletin. 29 (2): 440-455. \[Editor's
note: Paul B. Hamel, Southern Research Station scientist, co-authored
this publication.\]

Populations of most bird species associated with grassland, shrub-scrub
habitats, and disturbed areas in forested habitats (hereafter all
referred to as disturbance-dependent species) have declined steeply.
However, a widespread perception exists that disturbance-dependent
species are merely returning to population levels likely found by the
first European explorers and settlers. The fact that many
disturbance-dependent bird species and subspecies are now extinct,
globally rare, threatened, or endangered challenges that perception and
raises the question of balance between conservation efforts for birds
dependent upon disturbances and birds more closely associated with
mature forests. An overall understanding of the status and trends for
these disturbance-dependent species requires reconstruction of at least
thousands of years of Native American land use followed by 500 years of
post-European settlement. Interpretations herein on how to manage for
these disturbance-dependent species should support efforts to conserve
all landbirds in Eastern North America. **(27)**

Lee, Sang-Mook; Abbott, A. Lynn; Schmoldt, Daniel L. 2001. **Wane
detection on rough lumber using surface approximation.** In: Kline, D.
Earl; Abbott, A. Lynn., tech. eds. Proceedings: 4th international
conference on image processing and scanning of wood; IPSW 2000; 2000
August 21-23; Mountain Lake, VA. Blacksburg, VA: Virginia Tech,
Department of Wood Science and Forest Products: 89-96.

The initial breakdown of hardwood logs into lumber produces boards with
rough surfaces. These boards contain wane (missing wood due to the
curved log exterior) that is removed by edge and trim cuts prior to
sale. Because hardwood lumber value is determined using a

combination of board size and quality, knowledge of wane position and
defects is essential for selecting cuts that maximize profit. We have
developed a system that uses a structured-light system to obtain profile
(thickness) images of unplaned boards, in addition to gray-scale images
for defect detection. The focus of this paper is to describe a new
approach for detecting wane boundaries through the analysis of these

profile images. The problem is difficult because bark and other debris
adversely affect the laser-based imaging process, and because variations
in surface reflectance also cause inaccuracies in the resulting images.
The problem is compounded by the need to perform wane detection rapidly
in a manufacturing environment. The method that we have developed relies
on a combination of column-wise image statistics, selective smoothing,
and the analysis of surface shape. Initial wane edge estimates that are
obtained using the smoothed image are then refined by analysis of the
original image data. Based on visual assessment, the current method
appears to improve dramatically on traditional thresholding techniques.
**(28)**

Parresol, Bernard R. 2002. **Biomass.** In: El-Shaarawi, Abdel H.;
Piegorsch, Walter W. Encyclopedia of Environmetrics. Chichester: John
Wiley & Sons, Ltd.: 196-198.

Biomass, the contraction for biological mass, is the amount of living
material provided by a given area or volume of the earth\'s surface,
whether terrestrial or aquatic. Biomass is important for commercial uses
(e.g., fuel and fiber) and for national development planning, as well as
for scientific studies of ecosystem productivity, energy and nutrient
flows, and for assessing the contribution of changes in forest lands
(especially tropical) to the global carbon cycle. **(29)**

Selgrade, James F.; Roberds, James H. 2001. **On the structure of
attractors for discrete, periodically forced systems with applications
to population models.** Physica D. 158: 69-82.

This work discusses the effects of periodic forcing on attracting cycles
and more complicated attractors for autonomous f

systems of nonlinear difference equations. Results indicate that an
attractor for a periodically forced dynamical system may

inherit structure from an attractor of the autonomous (unforced) system
and also from the periodicity of the forcing. In particular, a method is
presented which shows that if the amplitude of the *k*‑periodic forcing
is small enough, then the attractor for the forced system is the union
of *k* homeomorphic subsets. Examples from population biology and
genetics indicate that each subset is also homeomorphic to the attractor
of the original autonomous dynamical system. **(30)**

Trani, Margaret K.; Brooks, Robert T.; Schmidt, Thomas L.; and others.
**Patterns and trends of early successional forests in the Eastern
United States.** Wildlife Society Bulletin. 29 (2): 413-424. \[Editor's
note: Victor A. Rudis, Southern Research Station scientist, co-authored
this publication.\]

We assessed the status of early successional forest conditions for 33
Eastern States within the New England, Middle Atlantic, Great Lakes,
Central Plains, Coastal South, and Interior South subregions. We used
Forest Inventory and Analysis surveys to analyze trends from 1946 to
1998. Dramatic regional differences occurred in distribution of early
successional forests. The northeastern region had the least proportion
of young forest (16 percent), followed by the north-central (24
percent), and southern (29 percent) regions. The least amount of young
forest occurred in the Central Plains (15 percent) and New England (16
percent), whereas the greatest occurred in the pine-dominated Coastal
South (32 percent). Differences also existed among individual States,
ranging from 3 percent (Illinois) to 38 percent (Alabama). Long-term
declines also were evident within the northeastern and north-central
regions. Selective harvesting, fire suppression, urban sprawl, and
cessation of agricultural abandonment contributed to the present
imbalance in distribution of young forests. Private ownership
predominates in the East and presents a significant challenge to provide
young forests. Absence of proactive management on private lands may
promote continued declines in early successional forest within many
eastern areas. **(31)**

Troggio, M.; Kubisiak, T.L.; Bucci, G.; Menozzi, P. 2001. **Randomly
amplified polymorphic DNA linkage relationships in different Norway
spruce populations.** Canadian Journal of Forest Research. 31:
1456-1461.

We tested the constancy of linkage relationships of randomly amplified
polymorphic DNA (RAPD) marker loci used to construct a population-based
consensus map in material from an Italian stand of *Picea abies* (L.)
Karst. in 29 individuals from three Norwegian populations. Thirteen
marker loci linked in the Italian stand did show a consistent locus
ordering in the Norwegian population. The remaining 16 unlinked marker
loci were spread over different linkage groups and (or) too far apart
both in the population map and in this study. The limited validity of
RAPD markers as genomic \"hallmarks\" resilient across populations is
discussed. We also investigated the reliability of RAPD markers; only 58
percent of the RAPD markers previously used to construct the consensus
map in the Italian population were repeat­able in the same material. Of
the repeatable ones, 76.3 percent were amplified and found polymorphic
in 29 megagametophyte sibships from three Norwegian populations.
**(32)**

Vose, James M.; Maass, Jose Manuel. 1999. **A comparative analysis of
hydrologic responses of tropical deciduous and temperate deciduous
watershed ecosystems to climatic change.** In: Aguirre-Bravo, Celedonio;
Franco, Carlos Rodriguez, comp. North American science Symposium: toward
a unified framework for inventorying and monitoring forest ecosystem
resources; 1998 November 2-6; Guadalajara, Mexico. Proceedings
RMRS-P-12. Fort Collins, CO: U.S. Department of Agriculture, Forest
Service, Rocky Mountain Research Station: 292-298.

Long‑term monitoring of ecological and hydrological processes is
critical to understanding ecosystem function and responses to
anthropogenic and natural disturbances. Much of the world\'s knowledge
of ecosystem responses to disturbance comes from long‑term studies on
gaged watersheds. However, there are relatively few long‑term sites due
to the large cost and commitment required to establish and maintain
them. Knowledge gained from these sites is also important for predicting
responses to future disturbances, such as climatic change, and these
sites should be the focal point for the development and validation of
predictive models. In this study, we apply a hydrologic model (PROSPER)
using climate, vegetation, and soil parameters from watersheds in the
mesic Southeastern United States and in the dry tropical forests of
Western Mexico to assess the overall effects of climatic change
(increased temperature and \[CO~2~\]) on watershed hydrology. We found
that evapotranspiration (ET) increased substantially in both ecosystem
types, with increases ranging from 24 to 42 percent. These increases
were directly attributable to changes in leaf energy balance and
evaporative demand. Streamflow decreased more substantially, with
virtually no streamflow under the greatest temperature increase scenario
(+20 percent) at the site in Western Mexico. Decreased stomatal
conductance was not sufficient to offset the effects of increased
temperature. **(33)**