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Compass Issue 8
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Compass is a quarterly publication of the USDA Forest Service's Southern Research Station (SRS). As part of the Nation's largest forestry research organization -- USDA Forest Service Research and Development -- SRS serves 13 Southern States and beyond. The Station's 130 scienists work in more than 20 units located across the region at Federal laboratories, universites, and experimental forests.



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Issue 8

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Natural Resources Inventory and Monitoring

1 Brandeis, Thomas J.; Delaney, Matthew; Parresol, Bernard R.; Royer, Larry. 2006. Development of equations for predicting Puerto Rican subtropical dry forest biomass and volume. Forest Ecology and Management. 233: 133-142.

Carbon accounting, forest health monitoring, and sustainable management of dry forests in Puerto Rico and other Caribbean Islands require accurate forest biomass and merchantable stem volume assessment. We destructively sampled 30 subtropical dry forest trees of 6 species near Ponce, Puerto Rico to develop equations that estimate leaf, woody, and total aboveground biomass, as well as inside and outside bark total and merchantable stem volume. Although our ability to accurately estimate subtropical dry forest biomass and merchantable volume in Puerto Rico has been improved, work remains to be done to sample a wider range of species and tree sizes.

2 Brandeis, Thomas James. 2006. Assessing tree species assemblages in highly disturbed Puerto Rican karst landscapes using forest inventory data. Plant Ecology. 186: 189-202.

Puerto Rico's northern karst belt was almost entirely deforested by the early 1950s, but economic policies that encouraged widespread agricultural abandonment have allowed reversion back to forest throughout the area. To improve understanding and management of these forests, this study describes the tree species communities that have formed and how these new forests reflect past land uses and topography. Forests typical of dry hill tops, abandoned coffee shade, early successional forest, and reverting pasture were found. Native tree species have returned and many introduced species, particularly African tuliptree, have become permanent parts of karst forest communities.

3 Randolph, KaDonna C. 2006. Descriptive statistics of tree crown condition in the Southern United States and impacts on data analysis and interpretation. Gen. Tech. Rep. SRS-94. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 17 p.

The U.S. Forest Service, Forest Inventory and Analysis Program (FIA) utilizes visual assessments of tree crown condition to monitor changes and trends in forest health. This report describes and discusses distributions of three FIA crown condition indicators (crown density, crown dieback, and foliage transparency) for trees in the Southern United States. Descriptive statistics are presented for all trees combined, by hardwood and softwood species groups, and for 53 individual species. Implications of these characteristics and other factors for the analysis of the phase 3 crown condition indicators are discussed.

4 Roesch, Francis A. 2007. Compatible estimators of the components of change for a rotating panel forest inventory design. Forest Science. 53(1): 50-61.

This paper introduces ways to make annual estimates of forest change, such as growth, removals, and mortality from Forest Inventory and Analysis data. Because the amount of data actually collected during a particular year is often insufficient to make low-variance estimates for that year, various modeling approaches are used to “borrow strength” from data gathered in surrounding years. One approach uses mixed estimation, which allows for the enforcement of constraints, such as ensuring that the total volume for a particular year is equal to the total volume from the previous year, plus entry and growth, minus mortality and harvest. The statistical properties of the candidate estimation systems are compared and contrasted in a sample simulation study.

5 Salajanu, Dumitru; Jacobs, Dennis M. 2005. Assessing biomass and forest area classifications from MODIS satellite data while incrementing the number of FIA data panels [CD-ROM]. In: Proceedings: American Society for Photogrammetry and Remote Sensing. Additional information: www.asprs.org/.

Satellite remote sensing is an important tool for monitoring vast areas of forestland in a short period of time. Forest Inventory and Analysis strives for an annual 20 percent sample of all field inventory plots in the Southern States. The objective of this study was to determine whether there is significant improvement in the accuracy of forest/non-forest and biomass classifications from MODIS satellite data by using the most recent two, three, or four panels of plot data as opposed to using the entire 5-year cycle of FIA data. Older plot data become less reliable with age. This work suggests only 3 panels are necessary to begin the modeling process for forest/ non-forest, but four or five panels of FIA plot information are needed to get a good classification. For good forest biomass results, all five panels should be used in the model.

6 Salajanu, Dumitru; Jacobs, Dennis M. 2006. The effect of using complete and partial forested FIA plot data on biomass and forested area classifications from MODIS satellite data [CD-ROM]. In: Proceedings: American Society for Photogrammetry and Remote Sensing. Additional information: www.asprs.org/.

The Forest Inventory and Analysis program performs annual measurements on a proportion of all lands to form rotating panels for 5-year reporting cycles. The main objective of this study was to determine whether there is significant improvement in the accuracy of biomass and forest/non-forest area classifications from MODIS satellite data by including partially forested FIA plots as opposed to only using 100 percent forested and 100 percent non-forested plots. Results show an increase in estimated forest area when multi-condition edge plots are included with the satellite and ancillary data in the modeling. Modeled biomass provides mapped satellite classification information on how forest biomass is spatially distributed throughout the state-wide forested landscape.

Forest Ecosystem Restoration and Management

7 Bragg, Don C. 2004. Composition, structure, and dynamics of a pinehardwood old-growth remnant in southern Arkansas. Journal of Torrey Botanical Society. 13(14): 320-336.

The Levi Wilcoxon Demonstration Forest has at least 27 different overstory taxa, with loblolly pine, shortleaf pine, and white oak dominating stand basal area. Hardwoods, including red maple, flowering dogwood, blackgum, and winged elm, were most common, especially in the subcanopy and understory. Large trees are scattered throughout the stand, some more than 100 cm d.b.h. and 40 m tall. Most canopydominant pines are 100 to 150 years old, and a few exceed 200 years. Salvage following natural disturbances has reduced dead-wood loads; without large-scale disturbances, pines, oaks, and sweetgum will decline, to be replaced by more shadetolerant species.

8 Bragg, Don C. 2005. Behavior and sensitivity of an optimal tree diameter growth model under data uncertainty. Environmental Modelling & Software. 20: 1225-1238.

Using loblolly pine, shortleaf pine, white oak, and northern red oak as examples, this paper explores the principles and behavior of potential relative increment (PRI) models of optimal tree diameter growth under data uncertainty. For instance, combining different State inventories prior to PRI model development increased sample size and diameter class representation while regionalizing the models. Generally, pooled models predicted the highest overall increment. Other tests comparing the structure of the data used to derive PRI models, naturalversus plantation-origin loblolly pine, and northern red oak from the Lake States and the Midsouth were provided.

9 Bragg, Don C. 2006. A taste of sowbelly and saleratus biscuit: Gifford Pinchot's Arkansas adventure. Arkansas Historical Quarterly. 65(3): 274-289.

Prior to his becoming the first Chief of the Forest Service, Gifford Pinchot spent a couple of weeks exploring the eastern Arkansas countryside with Bernard Fernow. This trip helped shape Pinchot's vision of American forests and the people who depended on them, and undoubtedly helped him construct his populist vision of natural resource management. While in Arkansas, Pinchot interacted with local politicians and boosters, loggers and mill workers, criminals and plain folk. He collected wood samples, struck up a friendship with a pet bear, and showed some of the first signs of his impending split with Fernow.

10 Graves, Don; Barton, Christopher D. 2006. University of Kentucky, College of Agriculture ; Kentucky State University. Reclaiming the future: reforestation in Appalachia [DVD]. Extension Publication DFR-0074. Lexington, KY: University of Kentucky. [DVD format, 29:50-min.]. [Editor's note: The Forest Service, Southern Region provided funding for this project.]

Since the implementation of the Surface Mining Control and Reclamation Act, many opportunities have been lost for reforestation of surface mines in the Eastern United States. Excessive compaction of spoil material in the backfilling and grading process is the biggest impediment. As the result of reforestation research, a five step forestry reclamation approach is being recommended for successfully establishing productive forests on reclaimed surface mines. The goal is to reestablish the function of the forest, which includes enhancing wildlife habitat, improving water quality and stream systems, reducing flooding, erosion, and sedimentation, and improving air quality. The five steps for ecosystem restoration are explained on this DVD.

11 Greenberg, Cathryn H.; Tanner, George W. 2005. Spatial and temporal ecology of eastern spadefoot toads on a Florida landscape. Herpetologica. 61(1): 20-28.

Effective amphibian conservation must consider landscape population processes, but information at multiple scales is rare. We explore spatial and temporal patterns of breeding and recruitment by eastern spadefoot toads using 9 years of data from continuous monitoring with drift fences and pitfall traps at eight ephemeral ponds in longleaf pine-wiregrass sandhills. Young were successfully produced after only 5 of 23 breeding events. Only 4 of the 8 ponds produced young, and most were produced during 4 of the 9 years studied. Adult “population” trends reflected breeding effort rather than numbers per se; capture rates fluctuated dramatically among years, but showed no overall increase or decrease over time. This information can be used to generate realistic metapopulation models for spadefoot toads as a conservation planning tool.

12 Holmes, Thomas P.; Murphy, Elizabeth A.; Bell, Kathleen P. 2006. Exotic forest insects and residential property values. Agricultural and Resource Economics Review. 35(1): 155-166.

This paper presents a case study of the economic damages to homeowners in a northern New Jersey community due to an exotic forest insect—the hemlock woolly adelgid. Hedonic property value methods are used to estimate the effect of hemlock health on property values. A statistically significant relationship is established. Moreover, there are some signs of spillover impacts from hemlock decline, as negative effects are realized on parcels where declining hemlock stands are located, as well as on neighboring properties. These results give some indication of the benefits of potential control programs and strategies and also show support for community- or neighborhood-based programs in residential settings.

13 Johnsen, Kurt; Maier, Chris; Sanchez, Felipe. [and others]. 2007. Physiological girdling of pine trees via phloem chilling: proof of concept. Plant, Cell & Environment. 30(1): 128-134.

SRS researchers have provided the first proof of concept for a method that allows scientists to study belowground carbon allocation in trees without destroying them. They describe a reversible, nondestructive chilling method that stops the movement of carbon into root systems. Results were similar to physical girdling experiments, which stopped all carbon movement below ground but also killed the trees. This phloem-chilling method will be applied to the same trees at various times of the year and under a variety of environmental conditions, giving us the means to generate robust estimates of carbon allocation needed to construct more realistic and reliable carbon cycle models.

14 Kubisiak, Thomas L.; Milgroom, Michael G. 2006. Markers linked to vegetative incompatibility (vic) genes and a region of high heterogeneity and reduced recombination near the mating type locus (MAT) in Cryphonectria parasitica. Fungal Genetics and Biology 43:453-463.

Self/non-self recognition in fungi is known generally as vegetative incompatibility and is controlled by genes at multiple vegetative incompatibility (vic) loci. To find DNA markers linked to vic genes in the chestnut blight fungus, Cryphonectria parasitica, we constructed a preliminary genetic linkage map. We found markers closely linked to two vic genes (vic1 and vic2), making them candidates for positional cloning. Once vic genes have been successfully cloned, we will be able to begin testing a number of hypotheses regarding the transmission of infectious viruses that can effect strong biological control of the fungus in natural populations.

15 Loeb, Susan C.; O'Keefe, Joy M. 2006. Habitat use by forest bats in South Carolina in relation to local, stand, and landscape characteristics. Journal of Wildlife Management. 70(5): 1210-1218.

Knowledge and understanding of bat habitat associations and responses of bats to forest management are critical for effective conservation and management. However, few studies have been conducted on bat habitat use in the Southeast. Our objective was to identify important local, stand, and landscape factors influencing bat habitat use in northwestern South Carolina. Results suggest that early successional habitats and small openings and gaps within forest stands provide suitable commuting and foraging bat habitat. However, mature forests are important for some species. Forest management practices that provide a variety of age classes across the landscape and that create gaps and openings within mid- and late-successional stands will likely provide suitable habitat for bats in the mountains of South Carolina.

16 McCarthy, Heather R.; Oren, Ram; Finzi, Adrien C.; Johnsen, Kurt H. 2006. Canopy leaf area constrains [CO2]- induced enhancement of productivity and partitioning among aboveground carbon pools. Proceedings of National Academy of Sciences of United States of America. 103(51): 19356-19361.

Net primary productivity (NPP) is enhanced under future atmospheric [CO2] in temperate forests representing a broad range of productivity. Yet questions remain in regard to how elevated [CO2]-induced NPP enhancement may be affected by climatic variations and limiting nutrient resources, as well as how this additional production is distributed among carbon (C) pools of different longevities. We show that, spatially, the major control of NPP was nitrogen (N) availability, through its control on canopy leaf area index (L). Results underscore the importance of resolving [CO2] effects on L to assess the response of NPP and C allocation. Further study is necessary to elucidate the mechanisms that control the differential allocation of C among aboveground pools in different forest types.

17 McNab, W. Henry; Roof, Tracy; Lewis, Jeffrey F. 2006. Evaluation of Ikonos satellite imagery for detecting ice storm damage to oak forests in eastern Kentucky. In: Prisley, S.; Bettinger, P.; Hung, I-K.; Kushla, J., eds. Proceedings of 5th Southern Forestry and Natural Resources GIS conference. Athens, GA: Warnell School of Forestry and Natural Resources, University of Georgia: 128-138.

Ice storms are a recurring landscape-scale disturbance in the Eastern U.S., where they may cause varying levels of damage to upland hardwood forests. The extent and severity of storm damage in managed forests must be mapped and assessed so that economic loss can be estimated, products salvaged, and recovery activities planned. We evaluated high resolution satellite imagery as a tool for detecting damage to an oak-dominated forest in eastern Kentucky that had been affected by an ice storm. Accuracy in classifying low and high levels of damage ranged from 65 to 70 percent. Our results suggest that high resolution satellite imagery may be useful for detecting ice storm damage to upland hardwood forests.

18 Palmroth, Sari; Oren, Ram; McCarthy, Heather R. [and others]. 2006. Aboveground sink strength in forests controls the allocation of carbon belowground and its CO2-induced enhancement. Proceedings of National Academy of Sciences of United States of America. 103(51): 19362-19367. [Editor's note: SRS scientist Kurt H. Johnsen coauthored this paper.]

Researchers found that trees only increase wood growth from elevated CO2 if there is enough leaf area to support that growth. The main constraint on leaf area development, and thus wood growth, is soil nutrition. Without adequate soil nutrition, trees largely respond to elevated CO2 by transferring carbon belowground and recycling it back to the atmosphere through respiration. Thus, with sufficient soil nutrition, forests increase their ability to tie up, or sequester, increasing atmospheric CO2 concentrations. Forests still sequester C with lower soil nutrition but cannot take advantage of steadily increasing atmospheric CO2 due to increased use of fossil fuels. Many forests are deficient in soil nutrition, but forest management, including forest fertilization, can greatly increase growth rate and wood growth responses to elevated atmospheric CO2.

19 Prestemon, Jeffrey P.; Zhu, Shushuai; Turner, James A. [and others]. 2006. Forest product trade impacts of an invasive species: modeling structure and intervention trade-offs. Agricultural and Resource Economics Review. 35(1): 128-143.

An uncontrolled invasion of exotic Asian gypsy or nun moths would threaten domestic forests and could have global market consequences. A combination of forest damage and market responses to damage would result in an overall decline in forest stocks by about 0.3 percent nationwide over 30 years. Without trade policy responses by our trading partners, the market effects would be small across all product categories. If, on the other hand, our trading partners banned the importation of U.S. logs into their countries, effects would be economically significant, both domestically and globally, especially in markets for lumber, panels, and paper.

20 Rudolph, D. Craig; Burgdorf, Shirley J.; Schaefer, Richard R. [and others]. 2006. Status of Pituophis ruthveni (Louisiana pine snake). Southeastern Naturalist. 5(3): 463-472.

The Louisiana pine snake (Pituophis ruthveni) is a large constrictor that was historically limited to pine forests of eastern Texas and west-central Louisiana. Fire suppression, which reduces habitat for pocket gophers (the snake's primary prey), has resulted in widespread decline of this species. Despite intensive trapping efforts (in excess of 100,000 trap days) throughout the historic range, Southern Station scientists were only able to document six, mostly small, existing populations. This information on current status, combined with additional ecological data also being collected, will allow more effective management of the extremely rare and vulnerable species.

21 Rudolph, D. Craig; Ely, Charles A.; Schaefer, Richard R. [and others]. Monarch (Danaus plexippus L. Nymphalidae) migration, nectar resources, and fire regimes in the Ouachita Mountains of Arkansas. Journal of the Lepidopterists' Society. 60(3): 165-170.

Monarchs (Danaus plexippus) pass through the Ouachita Mountains in large numbers in September and October on their annual migration to overwintering sites in central Mexico. Monarchs depend on nectar resources to fuel their migratory movements, and they obtain nectar from a variety of plant species, especially tickseed sunflower (Bidens aristosa) and other composites. Research results suggest that widespread fire suppression since the early 1900s has substantially reduced nectar production for migrating monarchs in the Ouachita Mountains. Sites that are undergoing restoration to a shortleaf pine-bluestem grass community following thinning and frequent prescribed fire support increased abundances of nectar resources and migrating monarchs compared to untreated controls.

22 Sisco, P.H.; Kubisiak, T.L.; Casasoli, M. [and others]. 2005. An improved genetic map for Castanea mollissima/ Castanea dentata and its relationship to the genetic map of Castanea sativa. Abreau, C.G.; Rosa, E.; Monteiro, A.A., eds. Proceedings: 111th International Chestnut Conference. Acta Horticulturae: 693: 491- 495.

We have added 275 AFLP and 24 SSR markers and the 5SrDNA locus to a previously published genetic map based on a hybrid cross between Castanea mollissima and C. denata. The SSR markers, 5SrDNA locus, and one isozyme locus also permitted us to correlate the linkage groups in the published genetic map of C. sativa with those in our C. mollissima/C. dentata map. Correlating the map of European chestnut with that of American and Chinese chestnut will allow greater progress in mapping important physiological and adaptive traits across species boundaries.

23 Tuskan, G.A.; DiFazio, S.; Jansson, S. [and others]. 2006. The genome of black cottonwood, Populus trichocarpa (Torr. & Gray). Science. 313: 1596-1604. (Editor's note: SRS scientists C. Dana Nelson and N. Islam-Faridi co-authored this publication.)

This article announced the first complete DNA sequence of a tree, the black cottonwood (Populus trichocarpa). The study included the assembly of the cottonwood genome. Southern Station scientists contributed cytogenetics studies that helped the international research team reassemble the genome and begin to locate genes of both evolutionary interest and economic importance. They also generated and analyzed data to provide an estimate of the amount of functional DNA within the genome, an important parameter in validating the evolutionary history of the genome.

Forest Values, Uses, and Policies

24 Bowker, J.M.; Murphy, D.; Cordell, H.K. [and others]. 2006. Wilderness and primitive area recreation participation and consumption: an examination of demographic and spatial factors. Journal of Agricultural and Applied Economics. 38(2): 317-326.

This paper explores the influence of demographic and spatial variables on individual participation and consumption of wildland area recreation. Estimated models corroborate previous findings indicating that race (black), ethnicity (Hispanic), immigrant status, age, and urban dwelling are negatively correlated with wildland visitation, while income, gender (male), and education positively affect participation and use. A key finding is that when one accounts for distance (essentially the cost of getting there), while race still matters, it matters less. Results of models are combined with U.S. Census projections of total population, changes in population characteristics, and estimates of current national forest wilderness visitation estimates to give insight into pressure that might be expected on the Nation's designated wilderness during the next half century. Results generally indicate that per-capita participation and visitation rates will decline over time as society changes. Total wilderness participation and visitation will, however, increase, but at a rate less than population growth.

25 Gao, Heng; Shupe, Todd F.; Hse, Chung Y.; Eberhardt, Thomas. 2006. Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murray) Parl. Holzforschung. 60: 459- 462.

Chemicals present in Port-Orford cedar (Chamaecyparis lawsoniana (A. Murray) Parl.) bark are of interest for their antioxidant activities. One mechanism of activity exhibited by antioxidants involves the scavenging of free radicals which have known damaging effects. Free radical-scavenging assays were used to determine the antioxidant activities for fractions obtained from a crude bark extract after solvent partitioning. This provided extraction and partitioning processes for the isolation of antioxidants of interest. Results showed that the antioxidant activity of each fraction could be correlated with the presence of phenolic compounds. Applications for these phenolic antioxidants range from direct consumption as nutraceuticals to the incorporation into packaging materials for the protection of products from oxidation.

26 Grace, J.M., III. 2005. Forest operations and water quality in the South. Transactions of American Society of Agricultural Engineers. 48(2): 871-880.

Southern forests are some of the most productive forests in the U.S. Forest operations have been reported to influence nonpoint-source (NPS) pollution by disturbing natural processes that maintain water quality. Results of watershed-scale studies that investigated the effect of forest operations on water quality in the 13 Southern States are highly variable. However, taken collectively, the results indicate that forest operations have little impact on the quality of water draining from forests in the South. Based on this review, best management practices (BMPs) show the potential to protect water quality following forest operations.

27 Grace, J. McFero, III. 2007. Modeling erosion from forest roads with WEPP. In Proceedings: Environmental Connection 07, Conference 38. Steamboat Springs, CO: International Erosion Control Association: 12 p.

The Water Erosion Prediction Project (WEPP) was used to simulate sediment and runoff yield observed from field experiments on two Southern Appalachian forest roads during two distinct study periods (1995-2003 and 2003-2004). WEPP estimates are compared to measured erosion rates in the Southern Appalachians from 24 road sideslope erosion plots on the Talladega National Forest and three road sections on the Chattahoochee National Forest. Management practices modeled included rolled erosion control product (RECP) treatment, two vegetation mixtures, and an untreated condition. Model predictions of sediment yield were in good agreement with observed values in the field experiment.

28 Grace, J. McFero, III; Clinton, Barton D. 2006. Forest road management to protect soil and water. American Society of Agricultural Engineers Paper No. 068010. St. Joseph, MI: American Society of Agricultural Engineers: 1-14.

The pattern of use of national forest roads for recreation by the public has increased dramatically since the late 1940s and is expected to continue to increase beyond the rates observed today. However, research over the past 60 years clearly presents forest roads as a major source of sediment and soil erosion from forest watersheds. Road management is an important component in preserving and maintaining healthy forests throughout the Nation. This paper provides an overview of issues involved in managing forest roads, explores the benefit and efficacy of erosion and sediment control, and suggests areas requiring additional research and development.

29 Johnson, C.Y.; Floyd, M.F. 2006. A tale of two towns: black and white municipalities respond to urban growth in the South Carolina Lowcountry. Human Ecology Review. 13(1): 23-38.

Sea Islands off the South Carolina coast have experienced rapid development rates in the past half century. This trend is now impacting the rural Lowcountry (coastal) near Charleston, SC. A better understanding of traditional rural communities' responses to expanding urbanization is critical because of the obvious threat to the natural environment in rural areas and also because of the potential threat to the culture and value systems held by long-time residents. This exploratory, qualitative study examines the response of two municipalities to growth. Majority black “Newborn” has initiated legislative actions that may encourage growth and is much more receptive to development initiatives. In contrast, mostly white “Seaside Village” is strongly opposed to proposals that may result in development. The bifurcated town responses are theorized in terms of procedural justice and sense of place.

30 Johnson, Cassandra Y.; Bowker, J.M.; Cordell, H. Ken. 2006. Acculturation via nature-based outdoor recreation: a comparison of Mexican and Chinese ethnic groups in the United States. Environmental Practice. 7: 257-272.

This research considers acculturation by Mexican and Chinese groups in the United States and how participation in five nature-based outdoor recreation activities may be an indicator of acculturation to American society. We also posit that U.S.- born Chinese have a greater likelihood of participation compared to U.S.-born Mexicans. Results show Chinese immigrant participation is distinguished only slightly from Mexican immigrant participation; no differences were found between U.S.-born Chinese and U.S.-born Mexicans. Withingroup comparisons show immigrant Chinese participation to be more aligned with U.S.-born Chinese participation than immigrant Mexican participation to U.S.-born Mexican participation. Results from this study are intended to help raise awareness among environmental professionals of the different ways nature may be perceived by various cultural groups and also to alert managers to the important role natural resources can play in acculturating immigrants to U.S. society.

31 Mercer, D. Evan; Haggar, Jeremy; Snook, Ann; Sosa, Mauricio. 2005. Agroforestry adoption in the Calakmul Biosphere Reserve, Campeche, Mexico. Small-scale Forest Economics, Management, and Policy. 4(2): 163-184.

Since farmers engage in a complex, dynamic process of learning-by-doing, evaluating economic incentives, and assessing risks in deciding whether to adopt agroforestry systems, a multipronged research approach is required for a complete analysis of adoption potential and to develop effective interventions. A case study is presented to analyze potential for reforestation and improving livelihoods of small farmers through the adoption of agroforestry systems in the Calakmul Biosphere Reserve in Campeche, Mexico. Farmer participation in the research process, planning of production systems, and annual evaluations assisted farmers and researchers in identifying limitations, testing and evaluating alternatives, and improving the viability and sustainability of systems. Generally, households that originated from the Yucatan Peninsula with more education, more experience both in age of the head of household and technical and project experience, higher incomes, and those that had cleared more forestland were more likely to have experimented with agroforestry systems.

32 Wear, David N. 2005. Future forestland area in the U.S. South. In: Shupe, T.F.; Dunn, M.A., eds. Proceedings of Louisiana Natural Resources Symposium. Baton Rouge, LA: Louisiana State University Ag Center Research & Extension: 32-41.

The Southeastern United States has been heavily transformed by various forms of resource exploitation. A review of historical data shows that net change in forest area has been minimal, while much of the land in the region has experienced some change over time. Recent economic changes have accelerated urbanization in the region. Future forest area depends both on these urbanization factors and on the prospects for timber prices. A forecasting exercise shows that if timber prices remain low, the South could see strong net declines in forest area for the first time since the early 20th century.

Threats to Forest Health

33 Achtemeier, Gary L. 2005. Planned Burn-Piedmont. A local operational numerical meteorological model for tracking smoke on the ground at night: model development and sensitivity tests. International Journal of Wildland Fire. 14: 85-98.

PB-Piedmont is a high-end weather/smoke model designed to track smoke as it moves near the ground at night. The purpose of the model is to assist land managers in answering the following questions: “If I burn tomorrow, will I smoke up a road tomorrow night and, if so, where?” and “Now that I have burned today, where is my residual smoke most likely to be going tonight?” At night, winds become light and variable and cold air tends to flow downslope into local drainages. Thus, given the local lay of the land, smoke at night may move in unexpected directions and can impact transportation by moving across roadways and restricting visibility. Numerous accidents with fatalities and injuries have been caused by smoke/fog visibility obstructions.

34 Achtemeier, Gary L. 2006. Measurements of moisture in smoldering smoke and implications for fog. International Journal of Wildland Fire. 15: 517-525.

Smoke from wildland burning in association with fog has been implicated as a visibility hazard over roadways in the Southern United States. A project began in 2002 to determine whether moisture released during the smoldering phases of prescribed burns could contribute to fog formation. Temperature and relative humidity data were taken from 27 smoldering “smokes” during 2002 and 2003. These measurements revealed large variability of moisture. Theoretical calculations show that moisture from smoldering smokes is sufficient, under nocturnal conditions of light winds and entrapment, to raise relative humidity to 100 percent, to increase existing fog, and/ or to initiate fog where fog might otherwise not have occurred.

35 Achtemeier, Gary L; Glitzenstein, Jeff; Naeher, Luke P. 2006. Measurements of smoke from chipped and unchipped plots. Southern Journal of Applied Forestry. 30(4): 165-171.

There is an increasing use of mechanical chipping in place of prescribed fire in smoke-sensitive areas along the wildlandurban interface to try to eliminate the smoke problem. It has been countered that under certain circumstances, mechanical chipping could actually increase smoke production. Despite this study's limited scale due to expenses, there are several implications for land management. • The active burn phase smoke production in the chipped-burn plot was about 60 percent of that in the burn-only plot. • Extrapolated to an operational scale burn, it is clear that fairly high levels of smoke would still be produced in both active burn and smoldering phases. • For several years after chipping and before the chipped fuels have fully decayed into soil, chipped fuels could ignite and smolder in a manner analogous to the ignition of organic soils. Land managers should not use chipped areas as fire breaks or “fire stoppers” when planning prescribed burns.

36 Campbell, J.W.; Hanula, J.L.; Waldrop, T.A. 2007. Effects of prescribed fire and fire surrogates on floral visiting insects of the Blue Ridge Province in North Carolina. Biological Conservation. 134: 393-404.

Insect pollinators help maintain forest plant diversity, but the impacts of forest management practices on pollinators is unknown. We investigated prescribed burning and shrub control effects. Of 7921 flower visitors, Hymenoptera (mostly bees) was the most abundant and diverse order. We also caught seven families of butterflies (Lepidoptera), six families of beetles (Coleoptera), and two families of flies (Diptera). Most floral visitors were captured where the understory shrubs were cut and the plots were burned, while much lower numbers were caught on plots that had shrub control only, were burned only, or were not treated. Treatments that restore healthy forests also benefit pollinators.

37 DiCosty, Ralph J.; Callaham, Mac A., Jr.; Stanturf, J.A. 2006. Atmospheric deposition and re-emission of mercury estimated in a prescribed forest-fire experiment in Florida, USA. Water, Air, and Soil Pollution. 176:77-91.

How much mercury is emitted from prescribed fires in the South? Is the mercury emitted simply a “re-emission” of previous atmospheric deposition, or do southern forest soils have high levels of geologic mercury that are emitted during these fires? We compared mercury levels in burned and unburned soils at the Osceola National Forest (Florida) to begin answering these questions. Our data suggest that prescribed fires emit relatively small amounts of mercury and that this mercury is simply a “re-emission” of previous atmospheric deposition. However, data from other sites are needed before this conclusion can be confirmed.

38 Grove, Simon J.; Hanula, James L., eds. 2006. Insect biodiversity and dead wood: proceedings of a symposium for the 22nd International Congress of Entomology. Gen. Tech. Rep. SRS- 93. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 109 p.

Dead wood is anything but dead. It is the lifeblood of an intricate web of life in which insects feature prominently. The papers presented here consider both the basic ecology and evolutionary history of saproxylic (dead-wood dependent) insects and how such insects can be affected by management of the forests where most species live. Past management has not always been beneficial to saproxylic insects and in some parts of the world has harmed them greatly. With continued quality research, however, there is some prospect that future land management will be more accommodating to saproxylic insects.

39 Liu, Yongqiang. 2006. North Pacific warming and intense Northwestern U.S. fires. Geophysical Research Letters. 33(L21710): 1-5.

Seasonal fire predictions provide invaluable aid in planning fire-related activities. The sea surface temperature (SST) anomalies in the tropical Pacific have been used as an important predictor for wildfires in the South. But their relation to Northwest wildfires, the most intense among various continental U.S. regions, is weak. This study turned attention to other Pacific regions and found that the intense Northwest wildfires are closely related to warming in the North Pacific. A statistical model can be developed using the identified fire-SST relationships to predict seasonal fires in the Northwest, as well as other continental U.S. regions.

40 Liu, Yongqiang. 2005. Atmospheric response and feedback to radiative forcing from biomass burning in tropical South America. Agricultural and Forest Meteorology. 133: 40-53.

Biomass burning has been extensively used to clear forest and savannas. The released smoke particles can reduce the solar radiation absorbed by the Earth. An important issue is how much this reduction could offset global warming. This study investigates this issue by examining biomass burning in the Amazon region. The simulation indicates the extreme importance of biomass burning in regional climate change. The magnitude of the annual radiation change due to smoke is comparable to that caused by doubled CO2 in the burning region. However, different from the CO2 greenhouse effect, biomass burning causes reduction in radiation and therefore in surface temperature. This result is expected to be useful in projecting future climate change of a specific region due to various forcing sources, including biomass burning.

41 McLaughlin, S.B.; Nosal, M.; Wullschleger, S.D.; Sun, Ge. 2007. Interactive effects of ozone and climate on tree growth and water use in a Southern Appalachian forest in the USA. New Phytologist. 174: 109-124.

New studies with forest trees and small watersheds suggest that vegetation will use more water when exposed to increased levels of the air pollutant ozone, and thus the effects of drought predicted for a warmer climate may be amplified. We found that current levels of ozone in the mountains of eastern Tennessee amplified the effects of climate stresses on large tree growth, transfer of water from soil to the atmosphere, and rates of stream flow from forested watersheds in the region. This new research suggesting that current levels of ozone amplify water loss of forests could be important in providing improved estimates of the future effects of global warming on water use and availability in natural systems. The researchers stress the need to test these concepts further with additional forest types and climatic systems.

42 McLaughlin, S.B.; Wullschleger, S.D.; Sun, G.; Nosal, M. 2007. Interactive effects of ozone and climate on water use, soil moisture content, and streamflow in a Southern Appalachian forest in the USA. New Phytologist. 174: 125-136.

Documentation of the degree and direction of effects of ozone on transpiration of canopies of mature forest trees is critically needed to model ozone effects on forest water use and growth in a warmer future climate. Patterns of sap flow in stems and soil moisture in the rooting zones of mature trees, coupled with late-season stream flow, in three forested watersheds in east Tennessee were analyzed to determine relative influences of ozone and other climatic variables on canopy physiology and stream flow patterns. This new research suggesting that current levels of ozone amplify water loss of forests could be important in providing improved estimates of the future effects of global warming on water use and availability in natural systems. The researchers stress the need to test these concepts further with additional forest types and climatic systems.

43 Michael, J.L.; Batzer, D.P.; Fischer, J.B.; Gibbs, H.L. 2006. Fate of the herbicide sulfometuron methyl (Oust®) and effects on invertebrates in drainages of an intensively managed plantation. Canadian Journal of Forest Research. 36: 2497-2504.

Stream contamination and aquatic ecosystem impacts of sulfometuron methyl (Oust®) applied to catchments for weed control in short rotation plantations were studied. Sulfometuron methyl was detected at very low concentrations during the first three months following treatment. The faunal communities observed in these drainages were dominated by a diversity of invertebrates typical of wetland habitats such as midges, mosquitoes, water beetles, physid snails, and water fleas. Faunal communities in treated areas were not different from those of untreated areas after treatment. This finding suggests that environmental impacts from such use are minor if not nonexistent.

44 Miller, James H. 2006. Non-native wisteria control with herbicides. Wildland Weeds. 10(1): 19-21.

Chinese and Japanese wisterias are invasive woody vines throughout much of the South and Northeast that occur in widely scattered infestations. The entangled infestations of Asian wisterias are difficult to treat, and herbicide foliar sprays offer one viable option. Six herbicides were tested for control capability. Effective herbicides were Tordon™, Garlon™, Arsenal™, Accord™, and Transline™ at specific times and rates of application described in the report. Retreatments were necessary. Escort was not effective as tested. These outcomes identify a range of effective herbicides that can be prescribed for wisteria depending upon the situation and safety to surrounding vegetation and revegetation.

45 Miller, James H.; Allen, H. Lee; Zutter, Bruce R. [and others]. 2006. Soil and pine foliage nutrient responses 15 years after competing-vegetation control and their correlation with growth for 13 loblolly pine plantations in the Southern United States. Canadian Journal of Forest Research. 36: 2412-2425.

A 15-year collaborative study to determine the effects of the intensive control of competing vegetation on pine plantations was recently reported by SRS and university scientists. The work, conducted on 13 loblolly pine plantations across the South, found that pine productivity could be doubled with intensive vegetation control. However, soil nutrient concentrations decreased by one-fourth to one-half over time, and soil carbon, nitrogen, and calcium decreased most. Less foliar nitrogen and potassium occurred after early herbaceous treatments that controlled nitrogen fixers. Intensive pine culture has placed high demands on soil nutrient supplies that have not yet been replenished.

46 Miller, James H.; Loewenstein, Nancy J.; Hansen, Curtis J. 2006. Alabama Invasive Plant Council list of invasive plants by cultural use categories. Wildland Weeds. 10(1): 15-18.

Invasive plants migrate across land-use and water-use boundaries in the mixed southern landscape. They are shared by all and often originate from urban areas. To give recognition to this phenomenon, the Alabama Invasive Plant Council (ALIPC) has created its invasive plant list as a spreadsheet showing cultural categories— who plants and who is impacted. This is appropriate since ALIPC membership is open to all stakeholders, because only through cooperative efforts can this dilemma be effectively addressed.

47 Vogt, Peter; Riitters, Kurt H., Estreguil, Christine [and others]. 2007. Mapping spatial patterns with morphological image processing. Landscape Ecology 22: 171-177.

Previous national assessments of forest fragmentation identified the need for better indicators of fragmentation and more efficient computational approaches. Morphological image processing provides much higher spatial precision and thematic accuracy compared to a previous approach based on image convolution, while retaining the capability to label these features at the pixel level for any scale of observation. The implementation of the technique is demonstrated for a forest map of the Val Grande National Park in North Italy. The new technique will be used in the Forest Service 2010 national RPA Assessment required by the Resource Planning Act.

48 Vogt, Peter; Riitters, Kurt H.; Iwanowski, Marcin [and others]. 2007. Mapping landscape corridors. Ecological Indicators 7:481-488.

Corridors are important geographic features for biological conservation and biodiversity assessment. However, the identification and mapping of corridors is usually based on visual interpretations of movement patterns (functional corridors) or habitat maps (structural corridors), which has prevented their consideration in national assessments of forest spatial patterns. This paper presents a new method for automated mapping of structural corridors from satellite imagery, and demonstrates environmental reporting of forest corridors in northern Slovakia. The new method will be used in the Forest Service 2010 national RPA Assessment required by the Resource Planning Act.

49 Wickham, J.D.; Riitters, K.H.; Wade, T.G. [and others]. 2006. The effect of Appalachian mountaintop mining on interior forest. Landscape Ecology. 22: 179-187.

Southern Appalachian forests are predominantly interior because they are spatially extensive with little disturbance imposed by other uses of the land. Appalachian mountaintop mining increased substantially during the 1990s, posing a threat to the interior character of the forest. We used spatial convolution to identify interior forest at multiple scales on circa 1992 and 2001 land-cover maps of the Southern Appalachians. Our analyses show that interior forest loss was 1.75–5.0 times greater than the direct forest loss attributable to mountaintop mining. Mountaintop mining in the Southern Appalachians has reduced forest interior area more extensively than the reduction that would be expected based on changes in overall forest area alone. The loss of Southern Appalachian interior forest is of global significance because of the worldwide rarity of large expanses of temperate deciduous forest.

Forest Watershed Science

50 Coleman, M.; Tolsted. D.; Nichols, T. [and others]. Post-establishment fertilization of Minnesota hybrid poplar plantations. 2006. Biomass & Bioenergy. 30(8-9): 740-749.

Short rotation woody crops are fast growing tree plantations that can be harvested after 10 years or less. They can be used as an alternative energy source, including production of ethanol fuels. To maintain fast growth and gain maximum energy, short rotation woody crops require fertilization; but criteria to prescribe the amount to apply are complex because demand changes with age. We installed trials at numerous locations in western Minnesota energy crop plantations. Tree growth and sunlight intercepted by tree leaves increase with fertilization, even though recommended laboratory analyses did not predict such a response. Based on the results, we recommend changes to nutrient diagnosis and fertilizer prescription procedures.

51 Coleman, M.D.; Stanturf, J.A. 2006. Biomass feedstock production systems: economic and environmental benefits. Biomass & Bioenergy. 30(8-9): 693-695.

At a time of rising gasoline prices, there is tremendous demand for alternative energy sources. Biomass is an alternative energy source that is both economically and environmentally beneficial. The Short Rotation Woody Crops Operations Working Group meets biennially to discuss the latest findings in biomass feedstock production for energy and bio-based products. This issue of Biomass & Bioenergy includes the proceedings of the 2004 meeting held in Charleston, SC. Articles include a historical perspective on energy crops, worldwide bioenergy development, ethanol production, and descriptions of economic, biological, and operational aspects of cropping systems. The collection will serve as a reference for biomass crop production and bioenergy development.

52 De Steven, Diane; Sharitz, Rebecca R.; Singer, Julian H.; Barton, Christopher D. 2006. Testing a passive revegetation approach for restoring Coastal Plain depression wetlands. Restoration Ecology. 14: 452-460.

Across the Southeastern Coastal Plain region, seasonally ponded depression wetlands support distinctive plant diversity and provide critical wildlife habitat. Many of these unique wetlands were degraded or destroyed by historical drainage and conversion. Because of continued threats, conserving intact wetlands and restoring degraded sites are regional concerns. In an experiment testing several restoration methods, 16 degraded wetlands were restored by plugging surface ditches and harvesting out successional forest indicative of drained sites. Wetland plant species established successfully from seed banks, but some species typical of natural wetlands were absent. Passive revegetation may be adequate for restoration if seed banks have suitable plant species, but supplemental planting of selected species may be desirable in some cases. Re-establishing hydrology is key to revegetation success, but periodic droughts present an unavoidable challenge to restoring these rainfall-dependent wetlands.

53 Dosskey, M.G.; Helmers, M.J.; Eisenhauer, D.E. 2006. An approach for using soil surveys to guide the placement of water quality buffers. Journal of Soil and Water Conservation. 61(6): 344-354.

Riparian forest buffers may function better in some locations than in others for filtering pollutants out of agricultural runoff water. A simple method was developed for using information contained in soil surveys to identify better locations for filtering sediment and dissolved pollutants from surface and groundwater flow. The method provides an estimate of how well a buffer would work in each soil map unit. The mapped results can guide managers to locations where protection and installation of buffers would yield greater water quality benefits.

54 Flebbe, Patricia A.; Roghair, Laura D.; Bruggink, Jennifer L. 2006. Spatial modeling to project Southern Appalachian trout distribution in a warmer climate. Transactions of American Fisheries Society. 135: 1371- 1382.

In the Southern Appalachians, distribution of wild trout is presently limited by temperature and is expected to be limited further by a warmer climate. We produced a regional map of current wild trout habitat and developed a quantile regression model of the elevation–latitude boundary for trout. Combined with a lapse rate model, the boundary model was used to project future wild trout distributions over a range of increased temperature. If predictions of the Hadley Global Circulation Model (GCM) are assumed, approximately 53 percent of trout habitat would be lost, and if the more extreme Canadian GCM is used, 97 percent would be lost. With increasing temperature, fragmentation would increase, leaving populations in small isolated patches vulnerable to extirpation because recolonization is unlikely. The regional trout habitat map could be used for assessing impacts of other regional stressors.

55 Gardiner, Emile S.; Yeiser, Jimmie L. 2006. Underplanting cherrybark oak (Quercus pagoda Raf.) seedlings on a bottomland site in the Southern United States. New Forests. 32: 105-119.

Forest managers have long recognized the difficulty of regenerating oak seedlings in mature bottomland hardwood stands. Natural regeneration has been unreliable and difficult to predict, hard to encourage with stand management practices, and slow to respond to disturbance. Research demonstrated that partial stand harvesting followed by seedling underplanting can be used to establish cherrybark oak on bottomland sites. Application of a suitable herbicide solution can effectively reduce Japanese honeysuckle competition. This new regeneration practice could greatly improve sustainability of bottomland hardwood forests by facilitating establishment of the ecologically and economically valued bottomland oaks.

56 Kennedy, Thomas B.; Haag, Wendell R. 2005. Using morphometrics to identify glochidia from a diverse freshwater mussel community. Journal of North American Benthological Society. 24(4): 880-889.

Studies of freshwater mussel reproductive success in the wild have been hindered by an inability to identify larval stages (glochidia) of mussels. We measured shell length, hinge length, and height of glochidia from 21 mussel species occurring in the Sipsey River, Alabama, then tested our ability to identify unknown glochidia using these dimensions. Glochidial size differed widely among species, and we were able to classify 72 to 79 percent of glochidia to the correct species using discriminant function analysis. Unlike previous studies, we found that glochidia of closely related species were not necessarily more similar to each other than to glochidia of more distantly related species, indicating that considerable divergence in shell shape has occurred. Our results show that these three simple shell measurements can be useful for identification of unknown glochidia or for rapidly narrowing the range of potential species identifications.

57 Lockhart, Brian R.; Gardiner, Emile S.; Leininger, Theodor D. [and others]. 2006. Flooding facility helps scientists examine the ecophysiology of floodplain species used in bottomland hardwood restorations. Ecological Restoration. 24(3): 151-157.

Bottomland hardwood ecosystems, important for their unique functions and values, have experienced considerable degradation through deforestation, development, and drainage. Restoration requires a better understanding of biological components, especially plants, and their interactions with other biotic and abiotic components of the ecosystem. We describe a facility, named the Flooding Research Facility, where hydrological regimes can be manipulated to study ecophysiology of floodplain species. Key features of the facility include the ability to study flood frequency, duration, and light availability. Additionally, we provide an example of ongoing research on the effects of flooding and light availability on pondberry (Lindera melissifolia).

58 Landis, Thomas D.; Dreesen, David R.; Dumroese, R. Kasten. 2003. Sex and the single Salix: considerations for riparian restoration. Native Plants. 4(2): 110-117.

Most restoration projects strive to create a sustainable plant community, but exclusive use of vegetatively propagated material may prevent this goal. Hardwood cuttings of dioecious (plants are either male or female) willows and cottonwoods are widely used in riparian restoration projects. Usually, dormant cuttings are collected with little attention to the sex of the donor plants. A proper mixture of male and female plants may not be present in the collected plants—or they may be entirely just one sex. Collecting cuttings with a known ratio of males and females will enhance the possibility that the resultant plants will produce viable seeds on the restoration site and achieve the ultimate goal of a sustainable plant community.

59 Landis, Thomas D.; Dreesen, David R.; Pinto, Jeremy R.; Dumroese, R. Kasten. 2006. Propagating native Salicaceae for riparian restoration on the Hopi Reservation in Arizona. Native Plants. 7(1): 52-60.

Aggressive exotic plants Russian-olive (Elaeagnus angustifolia) and saltcedar (Tamarix ramosissima) have invaded many wetland and riparian areas on the Hopi Reservation in Arizona, excluding willows, cottonwoods, and other native plants. The tribe is removing these invasives and asked the Forest Service for help in propagating native species to plant in these project areas. Although much information is available on how to propagate willows and cottonwoods, some unique challenges exist on Hopi lands: some species are now very rare and some are in scattered locations of streams, wetlands, and seeps. These conditions must be considered during plant material collections to ensure that both genetic and sexual diversity are adequately represented.

60 Sharitz, Rebecca R.; Barton, Christopher D.; De Steven, D. 2006. Tree plantings in depression wetlands show mixed success. Ecological Restoration 24(2):114-115.

We evaluated a low-effort approach (no seedling protection, no competition control) for reforesting degraded Coastal Plain depressions with wetland tree species. Seedlings of baldcypress (Taxodium distichum) and swamp tupelo (Nyssa biflora) were planted at 15-ft spacing in eight depressional wetlands that were restored by clearing out successional vegetation and plugging drainage ditches. Seedling heights at planting averaged 41 and 22 inches, respectively. Nearly 80 percent of the baldcypress survived after four years, whereas the tupelo suffered over 75 percent mortality from flooding and drought stress. Existing guidelines for bottomland reforestation recommend a minimum tree seedling height of 18 inches; however, in depressional wetlands that remain ponded during the growing season, using taller seedlings or preferentially planting into shallow-water zones may improve survival.

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Pitcher plants in South Carolina
Pitcher plants in South Carolina
(Photo by Bill Lea, Forest Service, retired)