In winter of 2005, the Southern Research Station (SRS) launched the first issue of Compass, a new quarterly magazine
featuring the SRS science and scientists. Compass includes the catalog of articles of the previous smaller publication
of the same name. In addition, each issue will feature three or four articles on an issue selected for its pertinence to
forest ecosystems and quality of life in the South.
The Winter 2005 issue of Compass focuses on biomass as a potential renewable energy source and income generator for
rural communities in the South. The spring issue will focus on nonnative invasive plants, the summer on longleaf pine,
and fall on forest fragmentation and urbanization.
Compass:
perspectives & tools to benefit southern forest resources - Winter
2005The Biomass Challenge
What are we going to do with all that wood?
|
The Winter 2005 edition of Compass marks a dramatic change in design and
content. If you have only been receiving electronic copies of this
document you may want to
subscribe to our hard copy mailing list. (Issues of the SRS
Compass will be mailed to you at no charge.)
As with all previous versions of Compass, we will continue to make all
information contained within this publication is available electronically.
www.srs.fs.usda.gov/compass/
Download this Issue of Compass |
Southern Pine Ecosystems
Brockway, Dale G.; Outcalt, Kenneth W.; Tomczak, Donald J.; Johnson, Everett
E. 2005. Restoring longleaf pine forest ecosystems in the Southern United
States. In: Stanturf, John A.; Madsen, Palle, eds. Restoration of boreal and
temperate forests. Boca Raton, FL: CRC Press: 501-519.
Longleaf pine (Pinus palustris) ecosystems are native to nine states of the
southern region of the United States. Longleaf pine can grow on a variety of
site types including wet flatwoods and savannahs along the Atlantic and Gulf
Coastal Plain, higher droughty sand deposits from the fall line sandhills to
the central ridge of Florida, and the montane slopes and ridges of Alabama and
northwest Georgia up to 600 m. This region has a humid subtropical climate.
Maximum July temperatures average 29°C to > 35°C while minima during January
range from 0 to 13°C. The mean annual precipitation is 1,040 to 1,750 mm and
is well distributed through the year. The growing season is comparatively
long, ranging from 300+ days in Florida to 220 days along the northern limit
of longleaf. During the late summer and fall, hurricanes can develop over the
Atlantic Ocean, move westward, and impact coastal plain forests. Such tropical
storms are one of the principal large-scale disturbance agents for longleaf
pine forests growing near the seacoast.
Clark, Alexander, III. 2004. Impact of vegetation control and annual
fertilization on properties of loblolly pine wood at age 12. Forest Products
Journal. 54 (12): 90-96.
Loblolly pine (Pinus taeda L.) stands in the Coastal Plain and Piedmont of
Georgia were subjected to four intensive silvicultural regimes to monitor and
record relative tree growth. Treatments included intensive mechanical site
preparation; complete vegetation control with multiple applications of
herbicides; annual high rates of nitrogen fertilization; and complete
vegetation control plus annual high rates of nitrogen fertilization. In
response to the intense cultural practices, growth increased 270 percent in
the Coastal Plain and 58 percent in the Piedmont compared to the intensive
mechanical site preparation treatment. Increment cores were collected from
trees at age 12 to determine the impact of intensive cultural practices on
earlywood and latewood specific gravity and duration of juvenility. Trees were
also felled to determine the impact of intensive cultural practices on wood
stiffness, strength, and toughness.
Cohen, Susan; Braham, Richard; Sanchez, Felipe. 2004. Seed bank viability in
disturbed longleaf pine sites. Restoration Ecology. 12 (4): 503-515.
Some of the most species-rich areas and highest concentrations of
threatened and endangered species in the Southeastern United States are found
in wet savannah and flatwood longleaf pine (Pinus palustris Mill.)
communities. Where intensive forestry practices have eliminated much of the
natural understory of the longleaf ecosystem, the potential for
reestablishment through a seed bank may present a valuable restoration
opportunity. Longleaf pine sites converted to loblolly pine plantations and
non-disturbed longleaf sites on the Coastal Plain of North Carolina were
examined for seed bank presence and diversity. Conducting vegetation surveys
and examining the seed bank using the seedling emergence technique allowed for
verification of the seed bank presence, as well as evaluation of the quality
of the seed bank on disturbed longleaf pine sites. Forty-three species and
over 1,000 individuals germinated, and the seed banks of both the disturbed
and non-disturbed stand types contained species not noted in the vegetation
survey. Although many of these species were considered weedy and typical of
disturbance, numerous taxa were indicative of stable longleaf pine
communities. This study confirms both the presence and quality of seed banks
in highly disturbed former longleaf pine sites, suggesting that the seed bank
may be an important tool in restoration efforts.
Fischer, Joseph B.; Miller, James H. 2004. Ion chromatography as an alternate
to standard methods for analysis of macronutrients in Mehlich 1 extracts of
unfertilized forest soils. Communications in Soil Science and Plant Analysis. 35
(15-16): 2191-2208.
This study evaluates ion chromatography (IC) as an alternative to atomic
absorption (AA) and inductively coupled plasma spectrometry (ICP) for analysis
of potassium (K), magnesium (Mg), and calcium (Ca), and as an alternative to
antimonylmolybdate colorimetry and ICP for analysis of phosphorus (P)
macronutrients in Mehlich 1 extracts. Soils typical of pine forests in the
Southeastern United States were tested. IC correlates well with AA and ICP for
K and Ca, but not for Mg, unless conditions are chosen that resolve Mg from
manganese (Mn). IC does not correlate very well with colorimetry for P at
extract levels below 2 mg kg-1 or in extracts with high levels of dissolved
organic matter complexes of aluminum (Al) and iron (Fe). ICP results for P
exceed both IC and colorimetry by 3-5 mg kg-1 for all soils tested. The merits
of IC relative to AA, ICP, and colorimetry for forest soil testing are
discussed.
Rudolph, D. Craig; Ely, Charles, A. 2000. The influence of fire on
Lepidopteran abundance and community structure in forested habitats of eastern
Texas. Texas Journal of Science. 52 (4) supplement: 127-138.
Transect surveys were used to examine the influence of fire on lepidopteran
communities (Papilionoidea and Hesperioidea) in forested habitats in eastern
Texas. Lepidopteran abundance was greater in pine forests where prescribed
fire maintained an open mid- and understory compared to forests where fire had
less impact on forest structure. Abundance of nectar sources paralleled this
pattern of abundance. Taxonomic groups of Lepidoptera varied across forest
types in patterns coincident with their dependence on nectar sources and
tendency to fly in shaded habitats.
Wetlands, Bottomlands, and Streams
Adams, Susan B.; Warren, Melvin L., Jr.; Haag, Wendell R. 2004. Spatial and
temporal patterns in fish assemblages of Upper Coastal Plain streams,
Mississippi, USA. Hydrobiologia. 528: 45-61.
We assessed spatial, seasonal, and annual variation in fish assemblages
over 17 months in three small- to medium-sized, incised streams characteristic
of northwestern Mississippi streams. We sampled 17,962 fish representing 52
species and compared assemblages within and among streams. Although annual and
seasonal variability in assemblage structure was high, fish assemblages
maintained characteristics unique to each stream. High variability in fish
catch-per-unit-effort (CPUE) was exemplified in one site where total CPUE
increased an order of magnitude from July 1993 to 1994. Species turnover and
percent dissimilarity were often higher seasonally than annually, consistent
with a period of change in spring to early summer and a return to similar
species compositions between summers. Temporal variability was also high at
the individual species level, and no species were classified as “stable.”
Flashy hydrographs, created in part by stream channelization and incisions and
watershed deforestation, may play a large role in structuring these fish
assemblages. Extreme interannual variability in assemblages in the absence of
detectable habitat change has important implications for the statistical power
of fish monitoring programs designed to detect trends in fish assemblages over
time.
Coleman, Mark D.; Friend, Alexander, L.; Kern, Christel C. 2004. Carbon
allocation and nitrogen acquisition in a developing Populus deltoides
plantation. Tree Physiology. 24: 1347-1357.
We established Populus deltoides Bartr. stands differing in nitrogen (N)
availability and tested if: • N-induced carbon (C) allocation could be
explained by developmental allocation controls; • N uptake per unit root mass,
i.e., specific N-uptake rate, increased with N availability. Closely spaced (1
× 1 m) stands were treated with 50, 100, and 200 kg N ha-1 year 1-1 of
time-release balanced fertilizer (50N, 100N, and 200N) and compared with
unfertilized controls (0N). Measurements were made during two complete growing
seasons from May 1998 through October 1999. Repeated nondestructive
measurements were carried out to determine stem height and diameter, leaf
area, and fine-root dynamics. In October of both years, above- and belowground
biomass was harvested, including soil cores for fine-root biomass. Leaves were
harvested in July 1999. Harvested tissues were analyzed for C and N content.
Nondestructive stem diameter and fine-root dynamic measurements were combined
with destructive harvest data to estimate whole-tree biomass and N content at
the end of the year, and to estimate specific N-uptake rates during the 1999
growing season. Shoot growth response was greater in fertilized trees than in
control trees; however, the 100N and 200N treatments did not enhance growth
more than the 50N treatment. Root biomass proportions decreased over time and
with increasing fertilizer treatment. Fertilizer-induced changes in allocation
were explained by accelerated development. Specific N-uptake rates increased
during the growing season and were higher for fertilized trees than for
control trees.
Gardiner, Emile S.; Stanturf, John A.; Schweitzer, Callie J. 2004. An
afforestation system for restoring bottomland hardwood forests: biomass
accumulation of Nuttall oak seedlings interplanted beneath eastern cottonwood.
Restoration Ecology. 12 (4): 525-532.
Bottomland hardwood forests of the Southeastern United States have declined
in extent since European settlement. Forest restoration activities over the
past decade, however, have driven recent changes in land use through an
intensified afforestation effort on former agricultural land. This intense
afforestation effort, particularly in the Lower Mississippi Alluvial Valley,
has generated a demand for alternative afforestation systems that accommodate
various landowner objectives through restoration of sustainable forests. We
are currently studying an afforestation system that involves initial
establishment of the rapidly growing native species eastern cottonwood (Populus
deltoides Bartr. ex Marsh.), followed by enrichment of the plantation
understory with Nuttall oak (Quercus nuttallii Palm.). In this article, we
examine the growth and biomass accumulation by Nuttall oak seedlings to
determine whether this species can be established and whether it will develop
beneath the cottonwood overstory. Though establishment in the more shaded
understory environment reduced Nuttall oak growth, seedling function was not
limited enough to induce changes in plant morphology. Our results suggest that
an afforestation system involving rapid establishment of forest cover with a
quick-growing plantation species, followed by understory enrichment with
species of later succession, may provide an alternative method of forest
restoration on bottomland hardwood sites and perhaps other sites degraded by
agriculture throughout temperate regions.
Schmetterling, David A.; Adams, Susan B. 2004. Summer movements within the
fish community of a small montane stream. North American Journal of Fisheries
Management. 24: 1163-1172.
We studied movements by fishes in Chamberlain Creek, MT, from 24 July to 16
August 2001. We operated six weirs with two-way traps and one additional
upstream trap, separated by 14-1,596 m, to quantify the timing, direction, and
distance of movements and to estimate fish populations in the study reaches.
We trapped and marked 567 fish of seven species, including 368 westslope
cutthroat trout Oncorhynchus clarkii lewisi and 172 sculpin (slimy sculpin
Cottus cognatus and an unidentified species similar to mottled sculpin C.
bairdii). We recaptured 173 westslope cutthroat trout and detected net
movements as long as 1,581 m (median, 91 m). Bidirectional movements for 116
westslope cutthroat trout ranged from less than 18 to more than 1,581 m
(median, 64 m). Sculpin moved as far as 209 m (median, 26 m). We estimate that
14 percent of sculpin and 48 percent of westslope cutthroat trout were mobile
during the study. We captured all species more frequently at night or twilight
(n = 296) than during the day (n = 83) and more frequently moving downstream
(n = 419) than upstream (n = 277). These results demonstrate considerable
summer movement by the fish community in a small stream.
Mountain and Highland Ecosystems
Elliott, Katherine J.; Vose, James M.; Clinton, Barton D.; Knoepp, Jennifer
D. 2004. Effects of understory burning in a mesic mixed-oak forest of the
Southern Appalachians. In: Engstrom, R.T.; Galley, K.E.M.; de Groot, W.J.
(eds.). Proceedings of the 22nd Tall Timbers fire ecology conference: fire in
temperate, boreal, and montane ecosystems. Tallahassee, FL: Tall Timbers
Research Station; 272-283.
Information is lacking on ecosystem effects of understory burning in mesic
mixed-oak (Quercus spp.) forests of the Southern Appalachians. Native
Americans used periodic fires in these forests for driving game and opening
the forest. In April 1998, we conducted a low- to moderate-intensity fire in a
cove hardwood forest in the Nantahala National Forest, western North Carolina.
In March 1998, before burning, permanent plots were established along three
parallel transects to measure forest floor mass, carbon, and nitrogen; soil
nutrient availability; and vegetation mortality and regeneration. Forest floor
material was sampled by components: small wood, litter, and a combined
fermentation and humus component. Soil nutrient availability was estimated
using cation and anion exchange membrane sheets. Vegetation measurements
included the overstory and understory layers. All parameters were resampled
during summer 1998 and 1999 in the same manner as the pre-burn inventories.
Moderate-intensity understory burning may be a useful tool to restore mesic
mixed-oak communities in the Southern Appalachians. Reintroduction of fire
into these ecosystems may be beneficial by increasing soil nutrient
availability, promoting regeneration and survival of Quercus spp., increasing
diversity of understory species, and reducing abundance of shade-tolerant and
fire-intolerant species such as Acer rubrum.
Vose, James M.; Geron, Chris; Walker, John; Raulund-Rasmussen, Karsten. 2005.
Restoration effects on N cycling pools and processes. In: Stanturf, John A.;
Madsen, Palle, eds. Restoration of boreal and temperate forests. Boca Raton, FL:
CRC Press: 77-94.
We presented two different aspects of evaluating effects of restoration on
biogeochemical cycling and aquatic ecosystems. The first examined the direct
responses of nutrient cycling pools and processes to restoration efforts aimed
at improving nitrogen retention and processing degraded riparian zones. The
second, stream NO3¯ responses of restoration burning, examined responses to
restoration efforts that do not target biogeochemical cycling per se, but
directly or indirectly influence nutrient cycling pools and processes. We
presented an approach to evaluate short- and long-term responses of
restoration on biogeochemical cycling using the resistance and resilience
analogy. Our adaptation of the resistance/resilience analogy to evaluate
restoration responses focused on three key attributes:
• The complexity of ecosystem biogeochemical cycling requires the
determination of key indicators of response.
• Evaluation of responses (direct or nontarget) can be approached by assessing
response magnitude and duration.
• Variable responses should be expected since the impacts of degradation may
impact pools and processes differently.
Inventory and Monitoring
Bechtold, William A. 2004. Largest-crown-width prediction models for 53
species in the Western United States. Western Journal of Applied Forestry. 19
(4): 245-251.
The mean crown diameters of stand-grown trees 5.0 inch d.b.h. and larger
were modeled as a function of stem diameter, live-crown ratio, stand-level
basal area, latitude, longitude, elevation, and Hopkins bioclimatic index for
53 tree species in the Western United States. Stem diameter was statistically
significant in all models, and a quadratic term for stem diameter was required
for some species. Crown ratio and/or Hopkins index also improved the models
for most species. A term for stand-level basal area was not generally needed
but did yield some minor improvement for a few species. Coefficients of
variation from the regression solutions ranged from 17 to 33 percent and model
R2 ranged from 0.15 to 0.85. Simpler models, based solely on stem diameter,
are also presented.
Large-Scale Assessment and Modeling
Butnor, J.R.; Johnsen, K.H. 2004. Calibrating soil respiration measures with
a dynamic flux apparatus using artificial soil media of varying porosity.
European Journal of Soil Science. 55: 639-647.
Measurement of soil respiration to quantify ecosystem carbon cycling
requires absolute, not relative, estimates of soil CO2 efflux. We describe a
novel, automated efflux apparatus that can be used to test the accuracy of
chamber-based soil respiration measurements by generating known CO2 fluxes.
Artificial soil is supported above an air-filled footspace wherein the CO2
concentration is manipulated by mass flow controllers. The footspace is not
pressurized so that the diffusion gradient between it and the air at the soil
surface drives CO 2 efflux. Chamber designs or measurement techniques can be
affected by soil air volume, hence properties of the soil medium are critical.
On the least porous soil, small underestimates (< 5 percent) of CO2 effluxes
were observed, which increased as soil diffusivity and soil porosity
increased, leading to underestimates as high as 25 percent. Differential
measurement bias across media types illustrates the need for testing systems
on several types of soil media.
Holmes, Thomas P.; Prestemon, John M.; Pye, John M. [and others]. 2004. Using
size-frequency distributions to analyze fire regimes in Florida. In: Engstrom,
R.T.; Galley, K.E.M.; de Groot, W.J. (eds.). Proceedings of the 22nd Tall
Timbers fire ecology conference: fire in temperate, boreal, and montane
ecosystems. Tallahassee, FL: Tall Timbers Research Station; 88-94.
Wildfire regimes in natural forest ecosystems have been characterized with
power-law distributions. In this paper, we evaluated whether wildfire regimes
in a human-dominated landscape were also consistent with power-law
distributions. Our case study focused on wildfires in Florida, a State with
rapid population growth and consequent rapid alteration of forest ecosystems
and natural fire regimes. We found that all fire size-frequency distributions
evaluated in this study were consistent with power-law distributions, but the
power-law distributions were piece-wise linear. A kink in the power-law
distributions occurred at about 640 ha for flatwoods fires and at about 290 ha
for swamp fires. Above these levels, fires “exploded” into a catastrophic
regime. If the kink represents the level at which fires become immune to fire
suppression effort, we would expect that the location of the kink would occur
at smaller fire sizes during extreme fire years due to the increased
flammability of fuels and the relative scarcity of fire suppression resources.
We found this result for three of four extreme fire years in flatwoods
ecosystems and for all four extreme fire years in swamps. These results
suggest that catastrophic fires may not be possible to prevent and that
suppression efforts during extreme fire years may be best applied to strategic
areas that decrease the connectivity of fuels.
Foundation Programs
Cowling, Ellis B.; Kelman, Arthur; Powers, Harry R., Jr. 1999. George Henry
Hepting: pioneer in forest pathology. Annual Review of Phytopathology. 37-19-28.
Hepting made significant and complex contributions to forest science on a
diverse range of complex problems. He had the ability to identify primary
causal factors and rapidly gain the depth of understanding of disease
situations that enabled him to devise practical approaches for management
practices. Long before the concepts of integrated pest management became
fashionable, Hepting emphasized the need to integrate disease hazard
evaluations and knowledge of disease development processes into economically
and biologically sound forest management systems. He also championed the need
for basic research as a foundation for practical understanding and management
of disease in forests. His role in the timber resources review of 1953 also
permanently changed our perception of the nature and magnitude of disease
losses in forests.
Greene, John L.; Straka, Thomas J.; Dee, Robert J. 2004. Nonindustrial
private forest owner use of Federal income tax provisions. Forest Products
Journal. 54 (12): 59-66.
Seven provisions of the Federal income tax provide incentives for
nonindustrial private forest (NIPF) owners to follow sound management and
reforestation practices. Four provisions are available to taxpayers in
general:
• Long-term capital gain treatment of qualifying income
• Annual deduction of management costs
• Depreciation and the section 179 deduction
• Deductions for casualty losses or other involuntary conversions
Three provisions are specifically for forest owners:
• Reforestation tax credit
• Amortization of reforestation expenses
• Ability to exclude qualifying reforestation cost-share payments from gross
income
NIPF owners in South Carolina were surveyed by mail to determine whether they
were aware of these tax provisions, whether they had made use of them, and
their reasons for using or not using each one. Information also was collected
on the owners’ demographic characteristics, to test for differences between
users and non-users of the provisions. Owner awareness and use was highest for
long-term capital gain treatment of income and annual deduction of management
costs. Some 78 percent of owners were aware of the two provisions, and 85
percent of owners who were aware of the provisions used them. Owner awareness
was lowest for the ability to exclude qualifying reforestation cost-share
payments, at 42 percent; owner use was lowest for loss deductions, at 23
percent. Membership in a forest owner organization, having a written forest
management plan, and a high level of household income were associated with
owner knowledge of beneficial tax provisions. No demographic characteristics
were associated across-the-board with owner use of provisions.
Mitchell, Dana; Ayala, Renee, comps. 2004. Biomass publications of the Forest
Operations Research Unit: a synthesis. [CD-ROM]. Auburn, AL. [Date accessed:
December 23, 2004].
The Forest Operations Unit of the Southern Research Station has been
studying biomass-related topics since 1977. This CD aids the reader by
organizing these publications in one easy-to-use CD, comprised of an executive
summary, two bibliographies, individual publications (in PDF format), and a
keyword listing. The types of publications included on this CD are
presentation reports, published reports, portions of books, and Web postings.
Rauscher, H. Michael; Johnsen, Kurt, eds. 2004. Southern forest science:
past, present, and future. Gen. Tech. Rep. SRS-75. Asheville, NC: U.S.
Department of Agriculture, Forest Service, Southern Research Station. 394 p.
Forest scientists, managers, owners, and users have in common the desire to
improve the condition of southern forests and the ecosystems they support. A
first step is to understand the contributions science has made and continues
to make to the care and management of forests. This book represents a
celebration of past accomplishments, summarizes the current state of
knowledge, and creates a vision for the future of southern forestry research
and management.
Smith, Robert L.; Pohle, Wibke; Araman, Philip; Cumbo, Dan. 2004.
Characterizing the adoption of low-grade hardwood lumber by the secondary wood
processing industry. Forest Products Journal. 54 (12): 15-23.
This study investigated the adoption of low-grade lumber in the secondary
hardwood industry. Factors influencing decisions regarding the utilization of
low-grade lumber were identified and value-added opportunities to increase the
use of low-grade lumber among manufacturers currently using higher grades were
evaluated. Data were collected via a nationwide mail survey of secondary
hardwood manufacturers. The single most important barrier to the adoption of
low-grade lumber among secondary hardwood manufacturers is “low yield.” Larger
manufacturers and trade association members were found to utilize the lower
grades at higher percentages when compared to smaller manufacturers and
non-members. Value-added activities designed to enhance the usability of
low-grade lumber should focus on decreasing processing variability in
secondary operations.
U.S. Department of Agriculture, Forest Service. 2004. Forest residues
bundling project. [CD-ROM]. 0451-2C02-MTDC. Missoula, MT: Montana Technology and
Development Center, Forest Service.
The Forest Residues Bundling Project CD includes information from Bob
Rummer’s evaluation of the slash bundler. The CD also contains a full copy of
the New Technology for Residue Removal Report in both HTML and Acrobat
formats, and includes a 15-minute video of the study. This product also
includes a gallery of images suitable for use in PowerPoint presentations or
for Web sites.
