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Browse subject: forest policy
Number of records: 546

Forest Practices Code Guidebooks | Ministry of Forests - Government of British Columbia
About this Resource: The Ministry of Forests (Government of British Columbia) provides a series of practical forestry related guidebooks. Offerings are categorized: bark beetle management; biodiversity; boundary marking; channel assessment procedures;community watersheds; defoliator management; and dwarf mistletoe management. There are guidebooks for specific forest regions; the rest involve: fish streams; forest development; forest roads; generic forest health; wildlife management; landscape units; terminal weevils; pine stem rust; pruning; riparian management; root disease management; seed and vegetative material; silviculture prescription; soil conservation; soil rehabilitation; stand management; trails; tree wounding and decay; visual imapct assessment and watershed assessment.

European Forest Institute
About this Resource: The European Forest Institute's (EFI) mission is to conduct, promote and cooperate in the research of forests, forestry and forest products at the pan-European level, and to make the results of the research known to all interested parties, notably in the areas of policy formulation and implementation, in order to promote the conservation and management of forests for producing goods and services in a sustainable way. The website divides into three sections. EFI describes its' organization, its' activities, and offers a news service. Research emphasis concentrates on: forest ecology and management; forest products; markets and socioeconomics; policy analysis, forest resources and information. EFI is currently advancing seven database services from this website; while most is open, certain parts may be limited to EFI members and partners. These services include: EFIDAS (the European Forestry Information and Data Analysis System); EFISCEN (the EFI Forest SCENario Project); DFDE (the Database of Forest Disturbances in Europe); the Database on Forest Capacities in 18 European Countries; CIS (the Certification Information Service); the Forest Research Network; FINE (the Forest Information Services Network for Europe) and EFIS (the European Forest Information System). EFI offers details on publications; mostly descriptive, pointers identify: research reports, working papers, proceedings, discussion reports, internal papers and related documents.

FAO Forestry
About this Resource: This organization focuses on "how to use trees, forests and related resources to improve people's economic, environmental, social and cultural conditions while ensuring that the resource is conserved to meet the needs of future generations." The website provides information about the organization and also about forest management, forest products and services, forest and the environment, people and forests, policy and institutions, sector studies, assessment and monitoring, and interdisciplinary issues. The site also contains forestry department country profiles, an events calendar, a database and library, publication information, and processes information.

Forest Policy and Environment Programme (ODI)
About this Resource: The FPEP is a product of the Overseas Development Institute and focuses on policy in tropical forest districts. The website discusses the research being done and the people involved with it. The site also provides news, network information, publication information and ordering, and links to other related sites.

Pacific Forestry Centre
About this Resource: The Pacific Forestry Centre focuses on research in forest biology and forest resources. This includes research in remote sensing, biological control of weeds and insects, insect and disease management, alternative silvicultural systems, timber production, fire management, and ecosystem dynamics. Their website provides information about their research as well as information about related programs, policies, and publications.

Global Forest Information System
About this Resource: GFIS is an Internet gateway to forest information resources from around the world. Users can locate maps, datasets, web resources, journal articles, books and other resources relevant to their forest information needs.","GFIS is an internet gateway that provides access to various types of information resources through partnerships with information providers. GFIS search facilities (in the style of commonly used Internet search facilities), allows the user to locate forest related information through a single entry point based on the different search options.","* An updated version of a previous GFIS metadata search provides users with the ability to search the catalogues of information resources (a total of 130,000 metadata records) provided by GFIS partners. The metadata search allows users to search all metadata fields for specific terms or phrases.","* Browsing is a way of navigating among categories and their subcategories to pinpoint the resources that you want to search. GFIS offers browsing among selected information sources from its partners, organized by key types of resources.","* A GFIS Online resource search service uses the Google Web APIs, which is an experimental and free program. The Google API currently makes it possible to carry out 1,000 queries per day with a maximum of 10 keywords. Each query is confined to one single domain.","To describe the content of this information GFIS uses a standardized metadata format and provides conversion facilities for metadata submitted in other formats. In addition a universally accepted terminology facilitates the search operations and the respective results.

Forest Value Orientations in Australia: An Application of Computer Content Analysis
About this Resource: This article explores the expression of three forest value orientations that emerged from an analysis of Australian news media discourse about the management of Australian native forests from August 1, 1997 through December 31, 2004. Computer-coded content analysis was used to measure and track the relative importance of commodity, ecological and moral/spiritual/aesthetic forest value orientations. The number of expressions of these forest value orientations followed major events in forest management and policy, with peaks corresponding to finalization of Regional Forest Agreements and conflicts over forest management. Over the time period analyzed, the relative share of commodity value orientation decreased and the shares of the ecological and moral/spiritual/aesthetic value orientations increased. The shifts in forest value orientations highlight the need for native forests to be managed for multiple values and the need for continued monitoring of forest values.

Swedish University of Agricultural Sciences, Department of Forest Resource Management and Geomatics
About this Resource: The Department of Forest Resource Management and Geomatics focuses on education and research in the fields of statistics, forest management planning, remote sensing, forest inventory, and environmental monitoring. Courses are offered in statistics, computer science, forest management planning, forest inventry, remote sensing, GIS, and environmental monitoring. There is information about the program on the site. There are links to the Swedish National Forest Inventory and the National Inventory of Landscapes in Sweden, which is a national program for the monitoring of biodiversity.

Using Bayesian belief networks in adaptive management
About this Resource: Bayesian belief and decision networks are modelling techniques that are well suited to adaptive-management applications, but they appear not to have been widely used in adaptive management to date. Bayesian belief networks (BBNs) can serve many purposes, from illustrating a conceptual understanding of system relations to calculating joint probabilities for decision options and predicting outcomes of management policies. We describe the nature and capabilities of BBNs, discuss their applications to the adaptive-management process, and present a case example of adaptive management of forests and terrestrial lichens in north-central British Columbia. We recommend that those unfamiliar with BBNs should begin by first developing influence diagrams with relatively simple structures that represent the system under management. Such basic models can then be elaborated to include more variables, the mathematical relations among them, and features that allow assessment of the utility of alternative management actions or strategies. Users of BBNs should be aware of several important limitations, including problems in representing feedback and time-dynamic functions. Nevertheless, when properly used, Bayesian networks can benefit most adaptive-management teams by promoting a shared understanding of the system being managed and encouraging the rigorous examination of alternative management policies.

The forest vegetation simulator: a review of its structure, content, and applications
About this Resource: The Forest Vegetation Simulator (FVS) is a distance-independent, individual-tree forest growth model widely used in the United States to support management decisionmaking. Stands are the basic projection unit, but the spatial scope can be many thousands of stands. The temporal scope is several hundred years at a resolution of 5-10 years. Projections start with a summary of current conditions evident in the input inventory data. FVS contains a self-calibration feature that uses measured growth rates to modify predictions for local conditions. Component models predict the growth and mortality of individual trees, and extensions to the base model represent disturbance agents including insects, pathogens, and fire. The component models differ depending on the geographic region represented by regionally specific model variants. The differences are due to data availability and the applicability of existing models. The model supports specification of management rules in the input, such as thinning if density is too high. The rules can be extended to represent other factors. For example, the effect of climate change on stand development by entering rules that specify how growth and mortality will change in response to changing climate. Applications range from development of silvicultural prescription for single stands to landscape and large regional assessments. Key issues addressed with FVS include forest development, wildlife habitat, pest outbreaks, and fuels management. The predictions are used to gain insights into how forested environments will respond to alternative management actions. Broad-scale forest management policies have been studied with FVS. For the 30 years since the model was initially introduced, the development team has anticipated and provided needed enhancements and maintained a commitment to working with and training users. The existence of an adequate user interface and the continued use of the original programming language are often overlooked factors for the success of this model. Future work will focus on improving FVS by adopting recent biometric techniques and including new information linking geomorphology to mortality and growth. Extending the model to more closely represent biophysical processes and adapting the model so that it is more relevant to management questions related to predicted climate change are also foci. Providing ways to dynamically link FVS to other models is our current strategy for providing major new capabilities.

Historical disturbance regimes as a reference for forest policy in a multiowner province: a simulation experiment
About this Resource: Using a landscape simulation model, we examined ecological and economic implications of forest policies designed to emulate the historical fire regime across the 2 x 10⁶ ha Oregon Coast Range. Simulated policies included two variants of the current policy and three policies reflecting aspects of the historical fire regime. Policy development was guided by the management intentions of four owner groups: forest industry, nonindustrial private, state, and federal. Fire severity was emulated with green-tree retention standards; fire frequency was emulated with annual harvestable area restrictions; and fire extent was emulated with harvest-unit size regulations. Simulated disturbance-based policies produced age-class distributions closer to the estimated historical range than those created by the current policy. Within 100 years, proportions of younger forests were within the historical range, while older forests moved closer to, but remained below, historical conditions. In the near term, disturbance-based policies produced annual harvest volumes 20%-60% lower than those produced by the current policy. However, relative costs of disturbance-based policies diminished over time. Our results suggest that if expediting a return to historical age-class distributions at a provincial-scale was a goal, then public lands would be needed to provide large patches of old forest. In addition, this experiment illustrated that distributing costs and benefits of conservation policies equitably across multiple private landowners is a significant challenge.

Swedish Forest Industries Federation (Skogsindustrierna)
About this Resource: The Federation represents over 60 pulp and paper mills and over 170 sawmills and is involved in Swedish and European industrial policy, in market issues on wood mechanical products, and in employer issues. Their website provides information about the following issues: climate change, energy, environment, forest, product policy, research, transports, wood and timber. They provide several facts and figures, briefings, publication and surveys, and related links.

Adjacency externalities and forest fire prevention.
About this Resource: This paper models landowner behavior on timberland subject to damage by fire. We examine how management decisions by adjacent landowners yield outcomes that diverge from the social optimum, and consider how this divergence depends on landowner preferences and information. We conduct a numerical simulation in which landowners interact through the effects of their fire prevention activities on a common risk of fire. The results reveal significant social inefficiencies related to externalities associated with private fuel treatment decisions. We consider a policy for aligning social and private decisions by requiring landowners to share the government's cost of fire suppression.

Forest Carbon Dynamics in the Pacific Northwest (USA) and the St. Petersburg Region of Russia: Comparisons and Policy Implications
About this Resource: Forests of the United States and Russia can play a positive role in reducing the extent of global warming caused by greenhouse gases, especially carbon dioxide. To determine the extent of carbon sequestration, physical, ecological, economic, and social issues need to be considered, including different forest management objectives across major forest ownership groups. Private timberlands in the U.S. Pacific Northwest are relatively young, well stocked, and sequestering carbon at relatively high rates. Forests in northwestern Russia are generally less productive than those in the Northwestern U.S. but cover extensive areas. A large increase in carbon storage per hectare in live tree biomass is projected on National Forest timberlands in the U.S. Pacific Northwest for all selected scenarios, with an increase of between 157-175 Mg by 2050 and a near doubling of 1970s levels. On private timberlands in the Pacific Northwest, average carbon in live tree biomass per hectare has been declining historically but began to level off near 65 Mg in 2000; projected levels by 2050 are roughly what they were in 1970 at approximately 80 Mg. In the St. Petersburg region, average carbon stores were similar to those on private lands in the Pacific Northwest: 57 Mg per hectare in 2000 and ranging from 40 to 64 Mg by 2050. Although the projected futures reflect a broad range of policy options, larger differences in projected carbon stores result from the starting conditions determined by ownership, regional environmental conditions, and past changes in forest management. However, an important change of forest management objective, such as the end of all timber harvest on National Forests in the Pacific Northwest or complete elimination of mature timber in the St. Petersburg region, can lead to substantial change in carbon stores over the next 50 years.

Conversion and recovery of Puerto Rican mangroves: 200 years of change
About this Resource: Human activities have dramatically reduced the world's area of mangroves just as the ecological services they provide are becoming widely recognized. Improving the conservation tools available to restore lost mangroves would benefit from a better understanding of how human activities influence the conservation of these ecosystems. We took advantage of historical information and long-term landscape analyses to relate land use change with the area of mangroves in Puerto Rico. We found that mangroves experienced dramatic changes over the last 200 years, and four distinct eras of change were visible. During the agricultural era (1800-1940) the area of mangroves declined 45%. As the economy changed to industrial in the late 1940s the area of mangrove increase due to reduced land use pressure on the wetlands. Nevertheless, urban expansion between 1960s and 1970s produced another decline. Public concern for mangrove conservation resulted in the legal protection of all the mangroves in 1972, and since then their area has expanded. We found that past human activity altered the original proportion of mangrove species. The number and size of mangrove-forest fragments was impacted by land use, and urban areas had fewer and smaller fragments than vegetated areas. Uncontrolled expansion of urban areas emerged as a major threat to mangrove conservation. Mangroves are resilient and recover quickly when given an opportunity if the geomorphological and hydrological features of the habitat are not changed by their use. The key to conservation appears to be a combination of the type of human activity in mangrove watersheds combined with strong legal protection. The following steps are recommended: (1) identify the areas that satisfy the ecological requirements of mangrove development; (2) incorporate better zoning regulations to maintain these areas natural and to protect the fluxes of water, nutrients, and organisms in and out of the system; and (3) monitor results.

Analyzing the cost effectiveness of Santiago, Chile's policy of using urban forests to improve air quality
About this Resource: Santiago, Chile has the distinction of having among the worst urban air pollution problems in Latin America. As part of an atmospheric pollution reduction plan, the Santiago Regional Metropolitan government defined an environmental policy goal of using urban forests to remove particulate matter less than 10 μm (PM10) in the Gran Santiago area. We used cost effectiveness, or the process of establishing costs and selecting least cost alternatives for obtaining a defined policy goal of PM10 removal, to analyze this policy goal. For this study, we quantified PM10 removal by Santiago's urban forests based on socioeconomic strata and using field and real-time pollution and climate data via a dry deposition urban forest effects model. Municipal urban forest management costs were estimated using management cost surveys and Chilean Ministry of Planning and Cooperation documents. Results indicate that managing municipal urban forests (trees, shrubs, and grass whose management is under the jurisdiction of Santiago's 36 municipalities) to remove PM10 was a cost-effective policy for abating PM10 based on criteria set by the World Bank. In addition, we compared the cost effectiveness of managing municipal urban forests and street trees to other control policies (e.g. alternative fuels) to abate PM10 in Santiago and determined that municipal urban forest management efficiency was similar to these other air quality improvement measures.

Historical fire and vegetation dynamics in dry forests of the interior Pacific Northwest, USA, and relationships to Northern Spotted Owl (Strix occidentalis caurina) habitat conservation
About this Resource: Regional conservation planning frequently relies on general assumptions about historical disturbance regimes to inform decisions about landscape restoration, reserve allocations, and landscape management. Spatially explicit simulations of landscape dynamics provide quantitative estimates of landscape structure and allow for the testing of alternative scenarios. We used a landscape fire succession model to estimate the historical range of variability of vegetation and fire in a dry forest landscape (size ca. 7900km²) where the present-day risk of high severity fire threatens the persistence of older closed canopy forest which may serve as Northern Spotted Owl (Strix occidentalis caurina) habitat. Our results indicated that historically, older forest may have comprised the largest percentage of the landscape (~35%), followed by early successional forest (~25%), with about 9% of the landscape in a closed canopy older forest condition. The amount and condition of older forest varied by potential vegetation type and land use allocation type. Vegetation successional stages had fine-grained spatial heterogeneity in patch characteristics, with older forest tending to have the largest patch sizes among the successional stages. Increasing fire severities posed a greater risk to Northern Spotted Owl habitat than increasing fire sizes or frequencies under historical fire regimes. Improved understanding of historical landscape-specific fire and vegetation conditions and their variability can assist forest managers to promote landscape resilience and increases of older forest, in dry forests with restricted amounts of habitat for sensitive species.

Quantitative Evidence for Increasing Forest Fire Severity in the Sierra Nevada and Southern Cascade Mountains, California and Nevada, USA
About this Resource: Recent research has concluded that forest wildfires in the western United States are becoming larger and more frequent. A more significant question may be whether the ecosystem impacts of wildfire are also increasing. We show that a large area (approximately 120000 km²) of California and western Nevada experienced a notable increase in the extent of forest stand-replacing (“high severity”) fire between 1984 and 2006. High severity forest fire is closely linked to forest fragmentation, wildlife habitat availability, erosion rates and sedimentation, post-fire seedling recruitment, carbon sequestration, and various other ecosystem properties and processes. Mean and maximum fire size, and the area burned annually have also all risen substantially since the beginning of the 1980s, and are now at or above values from the decades preceding the 1940s, when fire suppression became national policy. These trends are occurring in concert with a regional rise in temperature and a long-term increase in annual precipitation. A close examination of the climate-fire relationship and other evidence suggests that forest fuels are no longer limiting fire occurrence and behavior across much of the study region. We conclude that current trends in forest fire severity necessitate a re-examination of the implications of all-out fire suppression and its ecological impacts.

Spatial analysis of Prostephanus truncatus (Bostrichidae: Coleoptera) flight activity near maize stores and in different forest types in southern Benin, West Africa
About this Resource: Weekly Prostephanus truncatus (Horn) flight activity, measured as the density of captured beetles in pheromone baited traps, was monitored for 76 consecutive weeks at 16 sites inside the Lama forest in southern Benin and at four sites in maize farmland just outside the forest. Prostephanus truncatus flight activity was consistently higher and the flight activity pattern significantly different near maize stores than at sites inside the forest. Although P. truncatus is known to infest girdled branches of Lannea nigritana (Sc. Elliot) Keay, the P. truncatus flight activity was comparatively low at forest sites where this tree species dominated. The main peak in P. truncatus flight activity occurred earlier in the eastern part of the forest compared with other forest parts. Ordination analysis showed that comparatively higher flight activity in the eastern part of the forest was positively associated with the presence of teak plantations (Tectona grandis L. F.) at trap sites. The spatial distribution of weekly P. truncatus trap catches were found to be significantly aggregated during a 21-wk period, which largely coincided with the early increase in P. truncatus flight activity in the eastern part of the forest. Based on this evidence, it was suggested that P. truncatus individuals disperse from the eastern part of the forest to other forest parts and to nearby agricultural areas, rather than, as has been previously suggested, from maize stores to the forest environment.

Effects of Forest Regrowth and Urbanization on Ecosystem Carbon Storage in a Rural-Urban Gradient in the Southeastern United States
About this Resource: Forest regrowth after cropland abandonment and urban sprawl are two counteracting processes that have influenced carbon (C) sequestration in the southeastern United States in recent decades. In this study, we examined patterns of land-use/land-cover change and their effect on ecosystem C storage in three west Georgia counties (Muscogee, Harris, and Meriwether) that form a rural-urban gradient. Using time series Landsat imagery data including MSS for 1974, TM for 1983 and 1991, and ETM for 2002, we estimate that from 1974 to 2002, urban land use in the area has increased more than 380% (that is, 184 km²). Most newly urbanized land (63%) has been converted from forestland. Conversely, cropland and pasture area has decreased by over 59% (that is, 380 km²). Most of the cropland area was converted to forest. As a result, the net change in forest area was small over the past 29 years. Based on Landsat imagery and agricultural census records, we reconstructed an annual gridded data set of land-cover change for the three counties for the period 1850 to 2002. These data sets were then used as input to the Terrestrial Ecosystem Model (TEM) to simulate land-use effects on C fluxes and storage for the study area. Simulated results suggest that C uptake by forest regrowth (approximately 23.0 g C m⁻² y⁻¹) was slightly greater than the amount of C released due to deforestation (approximately 18.4 g C m⁻² y⁻¹), thus making the three counties a weak C sink. However, the relative importance of different deforestation processes in this area changed significantly through time. Although agricultural deforestation was generally the most important C-release process, the amount of C release attributable to urbanization has increased over time. Since 1990, urbanization has accounted for 29% of total C loss from the study area. We conclude that balancing urban development and forest protection is critically important for C management and policy making in the southeastern United States.

Estimating Suppression Expenditures for Individual Large Wildland Fires.
About this Resource: The extreme cost of fighting wildland fires has brought fire suppression expenditures to the forefront of budgetary and policy debate in the United States. Inasmuch as large fires are responsible for the bulk of fire suppression expenditures, understanding fire characteristics that influence expenditures is important for both strategic fire planning and onsite fire management decisions. These characteristics then can be used to produce estimates of suppression expenditures for large wildland fires for use in wildland fire decision support or after-fire reviews. The primary objective of this research was to develop regression models that could be used to estimate expenditures on large wildland fires based on area burned, variables representing the fire environment, values at risk, resource availability, detection time, and National Forest System region. Variables having the largest influence on cost included fire intensity level, area burned, and total housing value within 20 mi of ignition. These equations were then used to predict suppression expenditures on a set of fiscal year 2005 Forest Service fires for the purpose of detecting “extreme” cost fires--those fires falling more than 1 or 2 SDs above or below their expected value.

American Forest and Paper Association
About this Resource: The American Forest & Paper Association (AF&PA) is the national trade association of the forest, pulp, paper, paperboard and wood products industry. The site contains information and issues concerning pulp and paper, wood products, environment and recyling, and policy. There is a career center for both seekers and employers to use as well as a marketplace to purchase publications and products from the Association. The resource contains a section for educators and students as well as information on how to get involved in the environment.

Reduced-impact logging: Challenges and opportunities
About this Resource: Over the past two decades, sets of timber harvesting guidelines designed to mitigate the deleterious environmental impacts of tree felling, yarding, and hauling have become known as “reduced-impact logging” (RIL) techniques. Although none of the components of RIL are new, concerns about destructive logging practices and worker safety in the tropics stimulated this recent proliferation of semi-coordinated research and training activities related to timber harvesting. Studies in Southeast Asia, Africa, and South and Central America have clearly documented that the undesired impacts of selective logging on residual stands and soils can be substantially reduced through implementation of a series of recommended logging practices by crews that are appropriately trained, supervised, and compensated. Whether reducing the deleterious impacts of logging also reduces profits seems to depend on site conditions (e.g., terrain, soil trafficability, and riparian areas), whether the profits from illegal activities are included in the baseline, and the perspective from which the economic calculations are made. A standardized approach for calculating logging costs using RILSIM software is advocated to facilitate comparisons and to allow uncoupling RIL practices to evaluate their individual financial costs and benefits. Further complicating the matter is that while there are elements common to all RIL guidelines (e.g., directional felling), other components vary (e.g., slope limits of 17-40° with ground-based yarding). While use of RIL techniques may be considered as a prerequisite for sustaining timber yields (STY), in particular, and sustainable forest management (SFM), in general, RIL should not be confounded with STY and SFM. This confusion is particularly problematic in forests managed for light-demanding species that benefit from both canopy opening and mineral soil exposure as well as where harvesting intensities are high and controlled primarily by minimum diameter cutting limits. These qualifications notwithstanding, since logging is the most intensive of silvicultural treatments in most tropical forests managed for timber, some aspects of RIL are critical (e.g., protection of water courses) whether forests are managed for STY, SFM, or even replacement by agricultural crops.

Forestry Images : Forest Health, Natural Resources & Silviculture Images
About this Resource: A link to over 22,000 digital images devoted to forestry, natural resources, silviculture, incluing: forest pests, trees, understory and rangeland plants, wildlife, people, places and scenes. A substantial number of photos are public sector images; the downloading and use of which simply requires a registration. Availability results from a joint project involving The Bugwood Network, USDA's Forest Service, and the University of Georgia (engaging the Warnell School of Forest Resources and the College of Agricultural and Environmental Sciences).

The Demise of Fire and “Mesophication” of Forests in the Eastern United States
About this Resource: A diverse array of fire-adapted plant communities once covered the eastern United States. European settlement greatly altered fire regimes, often increasing fire occurrence (e.g., in northern hardwoods) or substantially decreasing it (e.g., in tallgrass prairies). Notwithstanding these changes, fire suppression policies, beginning around the 1920s, greatly reduced fire throughout the East, with profound ecological consequences. Fire-maintained open lands converted to closed-canopy forests. As a result of shading, shade-tolerant, fire-sensitive plants began to replace heliophytic (sun-loving), fire-tolerant plants. A positive feedback cycle-which we term “mesophication”-ensued, whereby microenvironmental conditions (cool, damp, and shaded conditions; less flammable fuel beds) continually improve for shade-tolerant mesophytic species and deteriorate for shade-intolerant, fire-adapted species. Plant communities are undergoing rapid compositional and structural changes, some with no ecological antecedent. Stand-level species richness is declining, and will decline further, as numerous fire-adapted plants are replaced by a limited set of shade-tolerant, fire-sensitive species. As this process continues, the effort and cost required to restore fire-adapted ecosystems escalate rapidly.

Effects of soil fumigants on methanotrophic activity
About this Resource: Negative impacts on methane (CH4) oxidation capacity have already been observed for a variety of agronomic practices, but the effect of soil fumigation on CH4 oxidation has not been investigated. Fumigation is a common practice in agricultural crop and nursery seedling protection. Soils from various agricultural experiment stations, forest nurseries, and a landfill were evaluated for effects of 1,3-dichloropropene (1,3-D), methyl isothiocyanate (MITC), and chloropicrin (CP) on CH4 oxidation capacities. All three fumigants significantly reduced CH4 oxidation rates in historically non-fumigated soils (>50%). 1,3-D enhanced CH4 oxidation in 3 out of 5 previously fumigated soils and MITC increased CH4 oxidation rates in all historically MITC-fumigated soils compared to controls. CP universally decreased oxidation capacity regardless of fumigation history. These results support the conclusion that CH4 oxidation effects are fumigant specific and that prior fumigation history plays a vital role in determining the impact on CH4 oxidizer community functionality, which may have implications on the global CH4 cycle.

Modeling of carbon sequestration in coastal marsh soils
About this Resource: Two transects were established across submerging coastal landscapes in Dorchester County, Maryland. Extensive sampling protocol was performed along the submerging upland tidal marsh soils to model C sequestration. Coastal marsh soils are accreting vertically and migrating laterally over the low-lying forest soils to keep pace with sea-level rise. The predictive C sequestration model was a two-step linear function. Therefore, C sequestration will continue to occur by accumulation in the organic horizons and sea-level rise is the driving force. During the last 150 yr, the rate of C sequestration averaged 83.5 ± 23 g m-2 yr-1. Before the last few hundred years, the predicted long-term rate of C sequestration averaged 29.2 ± 5.35 g m-2 yr-1. Sampling protocol and model validation ascertain the validity of the model and placed 80% confidence and 10% accuracy on rates of C sequestration and the predictive model. The model indicated that coastal marsh soils have higher C storage capacity than upland forest soils, and soils in the Cumulic subgroup of Mollisols. In general, C storage in mineral soils tends to reach a steady-state condition, whereas C sequestration in coastal marsh soils is a continuous phenomenon. During the next century, future C sequestration in the newly formed coastal marsh soils averaged 400 ± 162 g m-2 yr-1. Modeling C sequestration in coastal marsh ecosystems indicated that C storage under positive accretionary balance acts as a negative feedback mechanism to global warming.

Variations in sediment sources and yields in the Finger Lakes and Catskills regions of New York
About this Resource: The proportional contributions of stream bank and surface sources to fine sediment loads in watersheds in New York State were quantified with uncertainty analysis. Eroding streamside glacial drift, including glaciolacustrine deposits, were examined to help explain variations in the proportional contributions made by bank erosion. Sediment sources were quantified by comparing concentrations of the bomb-derived radionuclide 137Cs in fluvial sediment with sediment from potential source areas such as agricultural soils, forest soils and stream banks. To compare sediment sources in streams containing abundant deposits of fine-grained glacial drift with watersheds that lacked moderate or extensive streamside deposits, samples were taken from 15 watersheds in the region. The mean contribution of bank erosion to sediment loads in the six streams with glaciolacustrine deposits was 60% (range 46-76%). The proportional contribution of bank erosion was also important in one stream lacking glaciolacustrine deposits (57%) but was less important in the remainder, with contributions ranging from 0 to 46%. Data from this study on the varying contributions of bank erosion and data from past studies of sediment yield in 15 watersheds of New York State suggest that eroding streamside glacial deposits dominate sediment yield in many watersheds. In other watersheds, past impacts to streams, such as channelization, have also resulted in high levels of bank erosion.

Aggregate-size stability distribution and soil stability
About this Resource: A new theoretical and experimental framework that permits an accurate determination of aggregate-size stability distribution is presented. The size-stability distribution in addition to estimating aggregate-size distribution distinguishes between amounts of stable and unstable macroaggregates (>250 micrometer). The determination of aggregate-size stability distribution involves the assumptions that soil aggregates can be categorized in terms of their size and water stability (slaking resistance). Experimentally this procedure involves the slaked and capillary-wetted pretreatments; and a subsequent slaking treatment of aggregates >250 micrometer in size. We also propose the stable aggregates index (SAI) and the stable macroaggregates index (SMaI) for studying soil stability based on aggregate resistance to slaking. These indices account for the total weighted average of stable aggregates and the total weighted average of stable macroaggregates, respectively. Both the SAI and the SMaI indices were shown to be sensitive to the effects of vegetation on soil stability under different riparian buffer communities. The SAI and the SMaI indices were higher in surface soils under cool-season grass than any of the other treatments. These soils samples are well aggregated with SAI = 74% and SMaI = 56% followed by SAI = 55% and SMaI = 37% under existing riparian forest, SAI = 40% and SMaI = 21% under 7-yr switchgrass and SAI = 36% and SMaI = 18% under cropped system.

Large scale measurements of soil moisture for validation of remotely sensed data: Georgia soil moisture experiment of 2003
About this Resource: A series of soil moisture experiments were conducted in 2003 (SMEX03) to develop enhanced datasets necessary to improve spatiotemporal characterization of soil moisture and to enhance satellite-based retrievals. One component of this research was conducted in South Central Georgia of the US, from June 17th to July 21st (SMEX03 GA). This study analyzes measurements of soil moisture and temperature collected during SMEX03 GA. A network of in situ soil moisture measurement devices, established to provide validation data for the satellite collections and for long-term estimation of soil moisture conditions throughout the region, provided continuous measurements at 19 sites. Additional soil moisture and temperature validation data were collected daily from 49 field sites. These sites represented a diversity of land covers including forest, cotton, peanut, and pasture. Precipitation that occurred prior to June 22nd and from June 29th through July 2nd produced drying conditions from June 23rd to June 28th and gradual wetting from June 29th through July 2nd. Soil moisture in the top 0-1 cm of the soil was found to be more responsive to precipitation and to have greater variability than soil moisture at the 0-3 or 3-6 cm layers. Within different land covers, soil moisture followed the same trends, but varied with land use. Pasture sites were consistently the wettest while row-crop sites were normally the driest. Good agreement was observed between soil moisture measurements collected with the in situ network and the 49 SMEX sites. For the study period, soil moisture across the entire 50 km by 75 km region and five of the six 25 km by 25 km EASE-Grids demonstrated time stable characteristics. Time stability analysis and statistical tests demonstrated the in situ stations had a small dry bias as compared to the SMEX03 GA measurements. These results indicate that the in situ network will be a good resource for long-term calibration of remotely sensed soil moisture and provide a new and unique source for future satellite product validation.

Estimating surface soil organic carbon content at a regional scale using the National Resource Inventory
About this Resource: The National Resource Inventory (NRI) may be used to estimate soil organic C (SOC) levels at a regional scale if accurate and precise estimates can be made across a wide range of soils, land uses, and topographic positions. The objectives of this study were (i) to identify important sources of variation in SOC content at a regional scale and (ii) to determine the precision with which SOC content can be estimated. Surface soil samples (0-10 cm) were collected in four Major Land Resource Areas (MLRAs) and analyzed for SOC, sand, silt, and clay content. Land use, hillslope position, and slope aspect effects on SOC levels were evaluated by analysis of covariance with sand or clay content as a covariate to adjust for textural differences at each sample point. Land use was a significant source of variation in all four regions. Hillslope position and slope aspect were significant sources of variation in only one of the four regions and there were no significant interactions between land use and hillslope position or aspect. The SOC content ranged from 26 to 55 Mg ha 10 cm(-1) in the Northern Mississippi Valley Loess Hills, 22 to 50 Mg ha 10 cm(-1) in the Palouse and Nez Perce Prairies, 9 to 26 Mg ha 10 cm(-1) in the Central High Plains, and 5 to 8 Mg ha 10 cm(-1) in the Southern High Plains. Standard errors ranged from 0.5 to 5.0 Mg ha(-1) and were lowest in regions where SOC levels were also lowest. Results indicate the NRI can be an effective tool for estimating SOC levels under different land use and conservation practices on a regional scale.

Tannic acid reduces recovery of water-soluble carbon and nitrogen from soil and affects the composition of Bradford-reactive soil protein
About this Resource: Tannins are plant-derived polyphenolic compounds that precipitate proteins, bind to metals and complex with other compounds. Solutions of tannic acid, or other phenolic compounds, were added to soil samples to determine if they would affect recovery of soluble soil carbon (WSC) or -nitrogen (WSN) or influence the extraction and composition of Bradford-reactive soil protein (BRSP), associated with glomalin. Tannic acid-C added with water was not completely recovered from samples and the amount of total net WSC and WSN recovered was reduced, suggesting formation of insoluble complexes. By comparison, non-tannin phenolics like gallic acid, or methyl gallate, had little effect on extraction of WSC or WSN while a simple gallotannin derived from tannic acid, 1,2,3,4,6-penta-O-galloyl-d-glucose (PGG), inhibited extraction most. The C and N concentrations in BRSP increased when soil samples were treated with tannic acid or PGG before extraction, a procedure that includes autoclaving. Increases were greatest in the 10-20 cm compared to 0-5 cm depth. Accompanying these were declines in the ratio of absorbance at 465 and 665 nm (E4/E6 ratio) of BRSP extracts suggesting formation of larger or heavier molecules. In contrast, C and N composition in lyophilized BRSP was unaffected or even slightly reduced when tannic acid or PGG were added to the BRSP extract solution after the extraction process. We conclude that some tannins can reduce the solubility of labile soil C and N, at least temporarily and given unpredictability of response associated with phenolic substances, the Bradford assay should not be relied on to quantify pools or composition of soil proteins like glomalin.

Soil organic C and N pools under long-term pasture management in the Southern Piedmont USA
About this Resource: Soil organic matter pools under contrasting long-term management systems provide insight into potentials for sequestering soil C, sustaining soil fertility and functioning of the soil-atmospheric interface. We compared soil C and N pools (total, particulate and microbial) under pastures (1) varying due to harvest technique (grazing or haying), species composition (cool- or warm-season), stand age and previous land use and (2) in comparison with other land uses. Grazed tall fescue-common bermudagrass pasture (20 yr old) had greater soil organic C (31%), particulate organic C (66%), particulate organic N (2.4 fold) and soil microbial biomass C (28%) at a depth of 0-200 mm than adjacent land in conservation-tillage cropland (24 yr old). Soil organic C and total N at a depth of 0-200 mm averaged 3800 and 294 g m-2, respectively, under grazed bermudagrass and 3112 and 219 g m-2, respectively, under hayed bermudagrass. A chronosequence of grazed tall fescue suggested soil organic N sequestration rates of 7.3, 4.4 and 0.6 g m-2 yr-1 to a depth of 200 mm during 0-10, 10-30 and 30-50 yr, respectively. Soil C storage under long-term grazed tall fescue was 85 to 88% of that under forest, whereas soil N storage was 77 to 90% greater under grazed tall fescue than under forest. Properly grazed pastures in the Southern Piedmont USA have great potential to restore natural soil fertility, sequester soil organic C and N and increase soil biological activity.

Studying Fire Mitigation Strategies in Multi-Ownership Landscapes: Balancing the Management of Fire-Dependent Ecosystems and Fire Risk
About this Resource: Public forests are surrounded by land over which agency managers have no control, and whose owners expect the public forest to be a “good neighbor.” Fire risk abatement on multi-owner landscapes containing flammable but fire-dependent ecosystems epitomizes the complexities of managing public lands. We report a case study that applies a landscape disturbance and succession model (LANDIS) to evaluate the relative effectiveness of four alternative fire mitigation strategies on the Chequamegon-Nicolet National Forest (Wisconsin, USA), where fire-dependent pine and oak systems overlap with a rapidly developing wildland-urban interface (WUI). We incorporated timber management of the current forest plan and fire characteristics (ignition patterns, fire sizes, and fuel-specific fire spread rates) typical for the region under current fire suppression policies, using a combination of previously published fire analyses and interactive expert opinion from the national forest. Of the fire mitigation strategies evaluated, reduction of ignitions caused by debris-burning had the strongest influence on fire risk, followed by the strategic redistribution of risky forest types away from the high ignition rates of the WUI. Other treatments (fire breaks and reducing roadside ignitions) were less effective. Escaped fires, although rare, introduced significant uncertainty in the simulations and are expected to complicate fire management planning. Simulations also show that long-term maintenance of fire-dependent communities (that is, pine and oak) representing the greatest forest fire risk requires active management. Resolving conflict between the survival of fire-dependent communities that are regionally declining and continued rural development requires strategic planning that accounts for multi-owner activities.

Public land, timber harvests, and climate mitigation: Quantifying carbon sequestration potential on U.S. public timberlands
About this Resource: Scientists and policy makers have long recognized the role that forests can play in countering the atmospheric buildup of carbon dioxide (CO₂), a greenhouse gas (GHG). In the United States, terrestrial carbon sequestration in private and public forests offsets approximately 11% of all GHG emissions from all sectors of the economy on an annual basis. Although much of the attention on forest carbon sequestration strategy in the United States has been on the role of private lands, public forests in the United States represent approximately 20% of the U.S. timberland area and also hold a significantly large share (30%) of the U.S. timber volume. With such a large standing timber inventory, these forested lands have considerable impact on the U.S. forest carbon balance. To help decision makers understand the carbon implications of potential changes in public timberland management, we compared a baseline timber harvest scenario with two alternative harvest scenarios and estimated annual carbon stock changes associated with each. Our analysis found that a “no timber harvest” scenario eliminating harvests on public lands would result in an annual increase of 17-29million metric tonnes of carbon (MMTC) per year between 2010 and 2050--as much as a 43% increase over current sequestration levels on public timberlands and would offset up to 1.5% of total U.S. GHG emissions. In contrast, moving to a more intense harvesting policy similar to that which prevailed in the 1980s may result in annual carbon losses of 27-35 MMTC per year between 2010 and 2050. These losses would represent a significant decline (50-80%) in anticipated carbon sequestration associated with the existing timber harvest policies. If carbon sequestration were valued in the marketplace as part of a GHG offset program, the economic value of sequestered carbon on public lands could be substantial relative to timber harvest revenues.

Responses of insect pests, pathogens, and invasive plant species to climate change in the forests of northeastern North America: What can we predict
About this Resource: Climate models project that by 2100, the northeastern US and eastern Canada will warm by approximately 3-5 °C, with increased winter precipitation. These changes will affect trees directly and also indirectly through effects on "nuisance" species, such as insect pests, pathogens, and invasive plants. We review how basic ecological principles can be used to predict nuisance species' responses to climate change and how this is likely to impact northeastern forests. We then examine in detail the potential responses of two pest species (hemlock woolly adelgid (Adelges tsugae Annand) and forest tent caterpillar (Malacosoma disstria Hubner)), two pathogens (armillaria root rot (Armillaria spp.) and beech bark disease (Cryptococcus fagisuga Lind. + Neonectria spp.)), and two invasive plant species (glossy buckthorn (Frangula alnus Mill.) and oriental bittersweet (Celastrus orbiculatus Thunb.)). Several of these species are likely to have stronger or more widespread effects on forest composition and structure under the projected climate. However, uncertainty pervades our predictions because we lack adequate data on the species and because some species depend on complex, incompletely understood, unstable relationships. While targeted research will increase our confidence in making predictions, some uncertainty will always persist. Therefore, we encourage policies that allow for this uncertainty by considering a wide range of possible scenarios.

Drainage and agriculture impacts on fire frequency in a southern Illinois forested bottomland
About this Resource: Postsettlement (1909-2003) fire history of a forested bottomland in the Mississippi Embayment of southern Illinois, USA, was determined using fire-scar analysis. The study area is a forested bottomland hardwood site, with remnant pockets of the dominant presettlement bald cypress - tupelo (Taxodium-Nyssa) vegetation. Ditch drainage was installed in 1919, with agricultural clearing and abandonment varying throughout the early and mid-twentieth century. Commercial agricultural activities ceased after the site became part of a conservation area ca. 1950. The hydrology of the site was further modified in 1957 when it was inundated for waterfowl management. Both drainage and land clearing for agriculture were associated with increased fire frequency. Although drainage was a necessary precursor to agriculture across much of this landscape, land improvement played the stronger role in determining fire frequency. The mean fire interval for the study period (1895-1965) was 1.73 years, with a minimum of 1 year and a maximum of 15 years. This frequency contrasts with the complete fire exclusion that has prevailed in the area since 1965. These results have important implications for the maintenance and restoration of forested wetland ecosystems where the present fire regime differs dramatically from that under which the now-dominant forest vegetation developed.

Inference of adult female dispersal from the distribution of gypsy moth egg masses in a Japanese city
About this Resource: 1 The native range of the gypsy moth Lymantria dispar (L.) spans the temperate forests of Eurasia. Across this region, a clinal female flight polymorphism exists; gypsy moth females in eastern Asia are mostly capable of directed flight, those in western and southern Europe are largely incapable of flight and populations distributed across the centre of the distribution exhibit a range of intermediate flight behaviours. 2 Although information exists about the timing and duration of female flight from laboratory and wind tunnel studies, little or no quantitative data are available on average distances flown by Asian gypsy moth females prior to oviposition in the field. This information is critical for estimating risk of contamination at specific ports and transit terminals, as well as for predicting the spread of populations that might someday invade currently uninfested regions of the world. 3 In the present study, an extensive visual survey of gypsy moth egg masses was conducted during a walk through streets and paths in a 3.92 x 5.76 km area in Kanazawa, Japan. This area consisted of a matrix of urban, agricultural and forest land uses. The distribution of egg masses relative to distances from host forests was used to infer the magnitude of pre-ovipositional female flight. 4 A total of 3172 egg masses was recorded from surveys conducted during the search of a path totalling 384 km. Within urban areas, egg masses were most abundant in the area <1 km from the edge of forest land. 5 These results suggest that most female gypsy moth flight is limited to the area within 1 km of host forests. They also suggest that shipping containers and other parcels located >1 km from forests are at a much lower risk of contamination with Asian gypsy moth egg masses.

Understory Colonization of Eucalyptus Plantations in Hawaii in Relation to Light and Nutrient Levels
About this Resource: Exotic tree plantations may serve as catalysts for native forest regeneration in agriculturally degraded landscapes. In 2001, we evaluated plant species regeneration in the understory of a 7-year-old experimental Eucalyptus saligna forest in Hawaii approximately 1 year after the cessation of 5 years of herbicide. These forests were organized in a 2 x 2-factorial design of planting density (1 x 1- or 3 x 3-m spacing) and fertilization (unfertilized control and regular fertilization), which resulted in varying resource availabilities. We found that understory biomass was highest under high light conditions, regardless of fertilization treatment, whereas species richness was lowest under fertilized 1 x 1-m plots. The understory was dominated by species exotic to Hawaii. The most common tree species, the noxious weed Citharexylum caudatum, was particularly successful because high light-saturated photosynthesis rates and a low light compensation point allowed for high growth and survival under both light conditions. To assess longer-term recruitment patterns, we resurveyed a portion of this site in 2006 and also surveyed five Eucalyptus plantations in this region of Hawaii that differed in age (5-23 years), species (E. saligna, E. grandis, E. cloeziana, E. microcorys), and management (experimental, industrial, nonindustrial stewardship); all were established on previous agricultural sites within approximately 3 km of native-dominated forest. Again, very few native species were present in any of the stands, indicating that within certain landscapes and for native species with certain life history traits, exotic plantations may be ineffective nursery ecosystems for the regeneration of native species.

A bioeconomic approach to assess the impact of an alien invasive insect on timber supply and harvesting: a case study with Sirex noctilio in eastern Canada
About this Resource: This study presents a model that assesses the potential impact of a new alien insect species, Sirex noctilio Fabricius, on pine timber supply and harvest activities in eastern Canada. We integrate the spread of S. noctilio with a broad-scale growth and harvest allocation model. Projections of pine mortality range between 25 x 10(6) and 115 x 10(6) m3 over 20 years depending on S. noctilio spread and impact assumptions. Our model suggests Ontario could experience the highest, most immediate losses (78% of the potential losses across eastern Canada), with Quebec sustaining most of the rest of the losses over the next 20 years. Potential losses of $86 to $254 million per year are simulated after 20 years. The net present value of total harvest losses after 28 years of outbreak ranges between $0.7 to $2.1 billion. Adaptation policies decrease short-term losses by 46%-55% and delay larger harvest failures by 9-11 years. Without harvest adaptation, failures to maintain annual allowable cut levels may occur once the total area infested exceeds 15 x 106 ha. While better understanding and representing S. noctilio behaviour will involve a significant effort, there is a strong demand by policy makers for this kind of information.

National Agricultural Pest Information System
About this Resource: The National Agricultural Pest Information System (NAPIS) facilitates data management coordination for the plant pest survey's that are gathered on a national, regional, and state scale; and is a part of the Cooperative Agricultural Pest Survey (CAPS) program. NAPIS is sponsored by USDA/APHIS/PPQ. It provides the capabilities for entering, storing, processing, summarizing, managing, retrieving, graphing, and distributing plant pest survey data to the participants of the CAPS program and to other interested parties. NAPIS currently houses 1.3 million records on more than 3800 different organisms covering such diverse areas as insects, pathogens, weeds, and biological control organisms. Pointers and redirections from this page will access state regulatory news and pest survey information; domestic (U.S.) quarantine notices and APHIS Fact Sheets. Accessible through a server at Purdue University; through Purdue's Center for Environmental and Regulatory Information Sysyems (CERIS).

Sycamore and sweetgum plantation productivity on former agricultural land in South Carolina
About this Resource: Former agricultural lands in the southern US comprise a significant land base to support short rotation woody crop (SRWC) plantations. This study presents the seven-year response of productivity and biomass allocation in operational-scale, first rotation sycamore (Plantanus occidentalis L.) and sweetgum (Liquidambar styraciflua L.) plantations that were established on drained Ultisols which were historically planted in cotton and soybeans. Three plantation systems, sycamore open drainage, sycamore plus water management, and sweetgum open drainage were established on replicate 3.5-5.5 ha catchments. Height, diameter, and mortality were measured annually. Allometric equations, based on three, five, and seven year-old trees, were used to estimate aboveground biomass. Below-ground biomass was measured in year-five. Water management did not affect sycamore productivity, probably a result of a 5 year drought. The sycamore plantations were more productive after seven growing seasons than the sweetgum. Sycamore were twice the height (11.6 vs. 5.5 m); fifty percent larger in diameter (10.9 vs. 7.0 cm); and accrued more than twice the biomass (38-42 vs. 17 Mg ha-1) of the sweetgum. Sweetgum plantation productivity was constrained by localized areas of high mortality (up to 88%) and vegetative competition. Mean annual height increment has not culminated for either species. Diameter growth slowed in the sycamore during growing seasons five through seven, but was still increasing in the sweetgum. Both species had similar partitioning of above-ground (60% of total) and below-ground biomass (40% of total).

Methane oxidation and production activity in soils from natural and agricultural ecosystems.
About this Resource: Methane (CH4) flux from soil to the atmosphere is the result of two microbial processes, methanogenesis and CH4 oxidation. Land use may have a profound impact on the relative activities of these groups of organisms. In this study, the CH4 production and consumption potentials of soils from agricultural and nonagricultural ecosystems were assessed in laboratory incubations. Methane production potentials of most soils were low and in the range of 0.02 to 0.35 nmol CH4 g soil-1 h-1; however, soils from two of the agricultural sites that experience periodic water saturation had CH4 production potentials from 100 to 300 nmol CH4 g soil-1 h-1. The high methanogenic potential suggests that CH4 consumers may not be wholly dependent on atmospheric CH4 for their survival and maintenance. The prairie soils exhibited the highest CH4 oxidation under ambient atmospheric CH4 concentrations, and CH4 oxidation activity was markedly enhanced in incubations with an atmosphere enriched in CH4. This stimulated CH4 oxidation activity was generally greater in the agricultural soils as compared with the forest and prairie soils. Methane oxidation appeared to be related to soil nitrogen status. Under ambient atmospheric CH4 concentrations, CH4 oxidation was negatively related to soil mineral N concentration. However, a positive relationship between soil mineral N status and CH4 oxidation activity was observed in incubations with atmospheres enriched in CH4. This pattern suggests that the agricultural lands contain different populations of CH4 oxidizers than the natural systems.

Soil aggregation and glomalin under pastures in the Southern Piedmont USA
About this Resource: Soil aggregation is important for maintaining soil surface integrity and allowing water to infiltrate, rather than runoff and cause erosion. The effect of grazing animals on soil aggregation compared with other conservation management strategies in the Southern Piedmont USA is not well known. We tested a hypothesis that grazing animals might negatively affect soil aggregation characteristics. Water-stable macro-aggregates (>0.25 mm), mean-weight diameter, and their stabilities were (i) similar between conservation-tillage cropping and tall fescue (Festuca arundinacea Schreb.)-common bermudagrass (Cynodon dactylon L.) pasture; (ii) similar between 15- to 19-yr-old grazed and hayed hybrid bermudagrass; (iii) 7 to 14% greater in 30-yr-old than in 10-yr-old grazed tall fescue and hybrid bermudagrass pastures; (iv) similar among long-term grazingland, hayland, and forestland; and (v) 5 to 11% lower under cattle grazing than under monthly haying or unharvested management during the first 4 yr following conversion of cultivated cropland to pastureland. Water-stable aggregate distribution at a depth of 0 to 50 mm was 0.30 +/- 0.07 g g-1 in the 1.0- to 4.75-mm class, 0.46 +/- 0.07 g g-1 in the 0.25- to 1.0-mm class, 0.15 +/- 0.02 g g-1 in the 0.05- to 0.25-mm class, and 0.07 +/- 0.01 g g-1 in the <0.05-mm class, averaged across management systems and replications (n = 56). Total glomalin of the 1.0- to 4.75-mm dry-stable aggregate class was highly related to whole soil organic C content, but neither of these properties was particularly well related with water-stable macroaggregation, mean-weight diameter, or their stabilities. We conclude, overall, that grazing of pastures in the Southern Piedmont USA has little detrimental effect on soil aggregate distribution and stability and is comparable in soil conservation with other land conservation strategies.

Nursery Production Publications : Florida Extension Service
About this Resource: A link to the Florida Cooperative Extension publications on the topic of nursery production and nursery crops. A listing from the Electronic Data Information Source (EDIS), supported by the University of Florida's Institute of Food and Agricultural Sciences (UF/IFAS).

Policies and practices to sustain soil productivity: perspectives from the public and private sectors
About this Resource: The USDA Forest Service, the Canadian Forest Service, and US and Canadian forest products industries are committed to the principles of sustainable forestry with a major focus on protecting soil productivity. The USDA Forest Service has developed and adopted soil quality standards to evaluate the effects of forest use and management activities on forest soils and, if necessary, prescribe remedial or preventive actions to avoid adverse impacts on soil productivity. Similarly, the Canadian Forest Service has adopted a series of criteria and indicators with which to monitor the impacts of management on soil resources. The policies of both public agencies reflect the recommendations of the Montréal Process Working Group (1999). Many forest industries have adopted the Sustainable Forestry Initiative developed by the American Forest and Paper Association (2000). Standards of the Sustainable Forestry Initiative clearly state the vision and direction for achieving sustainable forest management, goals, and objectives to be attained and performance measures for judging whether a goal or objective has been achieved. However, both public and private entities recognize that current standards, criteria, and indicators represent first approximations. Continuing revision and adjustment based on information from long-term research studies are vital to protecting soil productivity while deriving optimum public benefits from our forest-based resources.

Land Use Change Effects on Forest Carbon Cycling Throughout the Southern United States
About this Resource: We modeled the effects of afforestation and deforestation on carbon cycling in forest floor and soil from 1900 to 2050 throughout 13 states in the southern United States. The model uses historical data on gross (two-way) transitions between forest, pasture, plowed agriculture, and urban lands along with equations describing changes in carbon over many decades for each type of land use change. Use of gross rather than net land use transition data is important because afforestation causes a gradual gain in carbon stocks for many decades, while deforestation causes a much more rapid loss in carbon stocks. In the South-Central region (Texas to Kentucky) land use changes caused a net emission of carbon before the 1980s, followed by a net sequestration of carbon subsequently. In the Southeast region (Florida to Virginia), there was net emission of carbon until the 1940s, again followed by net sequestration of carbon. These results could improve greenhouse gas inventories produced to meet reporting requirements under the United Nations Framework Convention on Climate Change. Specifically, from 1990 to 2004 for the entire 13-state study area, afforestation caused sequestration of 88 Tg C, and deforestation caused emission of 49 Tg C. However, the net effect of land use change on carbon stocks in soil and forest floor from 1990 to 2004 was about sixfold smaller than the net change in carbon stocks in trees on all forestland. Thus land use change effects and forest carbon cycling during this period are dominated by changes in tree carbon stocks.

Changing forests and forest management policy in relation to dealing with forest diseases
About this Resource: The forest landscape of the United States has changed over time, as has public concern for the trees, water, and wildlife. Early in the history of the United States, forests were viewed as an encumbrance and an inexhaustible resource, used to meet the needs of a growing nation. Around 1900, it became clear that old approaches were not sustainable and forest pathology saw its beginning. Annual lumber production increased from 5.4 billion to 44.5 billion board feet. Forest pathologists were called upon to help manage forests for a variety of products, with a focus on decays of wood and wood products. Projection of timber famine stirred public concern, and a number of laws were enacted to deal with the issue. Pathologists were called upon to deal with many of the issues associated with intensive management, and new pests such as chestnut blight and white pine blister rust demanded attention. Then pathologists were called upon to help manage for multiple benefits, and the issues became more complex. Pests such as mistletoes, root diseases, rusts, nursery pests, and urban pests presented new challenges. Concepts such as landscape level assessments, ecosystem management, and multiple-use led to the management of forests to provide for a complex variety of needs. Management objectives vary across the landscape, and pathologists find themselves working with managers who want to maximize fiber production, those that manage areas set aside for special purposes, and all combinations in between. Issues such as acceptable levels of pests, nonnative invasive species, landowner values, visual and watershed quality, and best management practices must be considered in an ever-changing landscape.

Mechanical properties and organic carbon of soil aggregates in the northern Appalachians
About this Resource: Aggregate properties determine the macroscale structural condition of the soil. Understanding of impacts of no-till and traditional agricultural practices on the mechanical properties of aggregates is fundamental to soil management. This study assessed the tensile strength (TS), bulk density (rho(agg)), soil moisture retention (SMR), and soil organic C (SOC) concentration of soil aggregates and determined the interrelationships among aggregate properties under long-term moldboard plow (MP), chisel plow (CP), disk with beef cattle manure (DM), no-till with beef cattle manure (NTM), no-till without beef cattle manure (NT), pasture, and forest systems in the North Appalachian region. Properties were determined on 1- to 8-mm aggregates from 0- to 30-cm soil depth. The TS and SMR (0 to -333 kPa) in NTM were higher than those in MP and CP (P < 0.01). The SOC concentration for NTM was higher than that for MP, CP, and NT (P < 0.01). The rho(agg) was 1.35 Mg m(-3) in NTM and approximately 1.61 Mg m(-3) in MP and CP (P < 0.01). Manuring had a positive and excessive tillage negative impact on aggregate properties. Aggregates from forest had the lowest TS (63 kPa) and rho(agg) (0.99 Mg m(-3)) and the highest SOC concentration (70 g kg(-1)), whereas the MP and CP had the highest TS (approximately 358 kPa) and the lowest SOC concentration (14 g kg(-1)) in 0- to 10-cm depth (P < 0.01). Mean rho(agg) was significantly higher than the density of bulk soil (rho(b)). The log-transformed TS (LogTS) increased with increasing rho(agg) and decreased with increasing aggregate size and SOC. Size, SOC concentration, and rho(agg) explained 84% of the variability of LogTS. Long-term (>35 yr) no-till combined with manuring improved the aggregate properties contrasting with conventionally cultivated systems.

14C Cycling in lignocellulose-amended soils: predicting long-term C fate from short-term indicators
About this Resource: We compared lignocellulose (the second most abundant component of plant material) degradation over 8 months in contrasting soils from each of five sites across the United States with the aim of assessing which soils are likely to store more C. The soils were collected from a tallgrass prairie restoration (farmland, and plots restored in 1993 and 1979), the semiarid shrub-steppe (cool, moist upper slope and warm, dry lower slope soils), long-term farmland (no-till and conventional-till), and from two forest soils (loblolly pine and Douglas fir; fertilized and nonfertilized). Soils that rapidly metabolized freshly added C exploited endogenous and newly transformed C to a lesser degree over the course of the incubation (lower slope shrub-steppe, nonfertilized Douglas fir, and tallgrass prairie farmed and 1993 restorations). We also pooled the data to find a strong relationship between sand content and lignocellulose C remaining in the soil after 8 months (R=0.68) and also between short-term storage of lignocellulose C (at 7 days) and lignocellulose C remaining after 8 months (R=0.94). To predict C storage, models of C and soil properties must be modified to reflect the structure and function of microbial communities. Communities in richer soils may be more competent to use native C following fresh C additions when compared with communities in poorer soils.