Forestry Best Management Practices Research Articles

A spatial dependence approach to assessing the impacts of Sustainable Forestry Initiative’s Fiber Sourcing certification on forestry Best Management Practices in Georgia, United States

Understanding the effectiveness of the Sustainable Forestry Initiative Fiber Sourcing (SFI-FS) standard in increasing/sustaining a high forestry Best Management Practices (BMP) implementation rate is critical for the overall sustainability of southern forestlands. We analyze the impacts of SFI-FS standard on the forestry BMP implementation rate in Georgia, United States, by considering the locations of certified and non-certified mills between 2002 and 2019. The results show each increasing non-certified sourcing area overlap reduces BMP rates by 0.15%, while the same rate goes up by 0.08% overall with each increasing certified sourcing overlap. Moreover, the results of the spatial analyses indicate that neighbors' certified overlaps have a negative effect on average forestry BMP rates associated with a sourcing mill, even though the overall effect is positive. An increase in own harvesting area and mill size reduces BMP rates by 0.056%, but an increase for neighboring sourcing mills increases them by 0.063%, showing an overall positive effect of these two variables. These findings reflect the supply chain inefficiency brought on by concurrent contracting behavior between small mills and their larger certified neighbors. BMP rates are higher in the mill sourcing area by 0.023%, with each increase in the presence of perennial streams, further indicating that loggers are adequately following BMPs in areas that have perennial streams. Our overall results show that spatial dependence is an essential mechanism for ascertaining the effectiveness of SFI-FS standard at large spatial scales.

Evaluating the feasibility and potential of unmanned aerial vehicles to monitor implementation of forestry best management practices in the coastal plain of the southeastern United States

Compared to undisturbed areas, timber harvest activities, including road construction, skid trails, and stream crossings, exhibit the potential for causing erosion and sedimentation if forestry best management practices (BMPs) are not implemented. Forestry BMP monitoring serves as a tool to evaluate BMP implementation status. Conventional on-the-ground BMP monitoring has contributed substantially to assessing BMP implementation. However, conventional on-the-ground surveys can be time consuming. Unmanned aerial vehicles (UAVs) have been rapidly emerging as a new tool for local-scale monitoring. In this study, we evaluated the feasibility and potential of UAVs for monitoring forestry BMPs in the coastal plain of southeastern United States. We compared the performance of UAV-live feed surveys and UAV-created map surveys with conventional on-the-ground surveys across major BMP categories on 30 study sites using BMP guidelines and implementation survey questions from Alabama, Georgia, and Florida for the sites specific to that state (10 sites in each state). The UAV-live feed surveys involved real-time assessments conducted using the live feed function, enabling on-the-spot evaluations. Whereas the UAV-created map surveys entailed autonomous UAV flight to collect imagery specifically for generating maps and facilitating subsequent assessments.We found that using a UAV for monitoring BMPs efficiently provided an overview of a timber harvest area from above. UAV-live feed surveys were as effective as conventional on-the-ground surveys across all major BMP categories. Specifically, the Cramer's V correlation between the responses from UAV-live feed and conventional on-the-ground surveys for all BMP categories, was 0.95 (p < 0.0001) for detecting implemented BMPs and 0.86 (p < 0.0001) for detecting when BMPs were not implemented but needed to be. UAV-created map survey results vs. conventional on-the-ground surveys were not as effective (V of 0.79 for detecting implemented BMPs and 0.46 for detecting BMPs not implemented but needed). Waste and stream crossing BMP implementation were the most difficult to verify using the map surveys, which was not an issue with the live feed surveys due to the capability to evaluate those BMPs at different camera angles. While UAV-created map surveys may be less effective, they provide an observation record that includes a map of the site. This project also developed a standardized framework for using UAVs to monitor forestry BMPs, including instructions and procedures for conducting UAV-live feed and map surveys. In conclusion, a UAV using the live feed function in the field is a feasible option to monitor forestry BMPs.

Increased levels of forestry best management practices reduce sediment delivery from Middle and Lower Coastal Plain clearcut harvests and access features, southeastern states, USA

Over 390,000 ha of forestland are clearcut annually (1–2%) across the Coastal Plain region of the southeastern U.S. where forestland occupies approximately 30 million hectares in the region. Extensive periods of high-water tables, wet-weather and harvesting, rutting, erodible soils, and drainage networks typical of the Coastal Plain increase the potential for erosion and stream sedimentation. To mitigate these impacts, water quality forestry Best Management Practices (BMPs) were developed for erosion and sediment control and are recommended and approved by all southeastern state forestry agencies for application during and after harvests. The goal of this study was to estimate erosion and sedimentation from silvicultural operations in the Coastal Plain under three different and previously recognized levels of BMP implementation including BMP– (<80%), BMP-standard (80%–90%), and BMP+ (>90%), where 90% represents average implementation. A total of 35 recent clearcut sites were evaluated in the Coastal Plain of 12 southeastern states. Erosion was estimated via the USLE-Forest model at five operational features, including decks, stream crossings, haul roads, skid trails, and harvest areas only, which were classified into one of three BMP levels. Sediment traps were utilized on a subset of Coastal Plain sites in Virginia and North Carolina so that sediment delivery ratios (unitless) could be calculated. Clearcut area estimates were obtained from the United States Forest Service (USFS), Forest Inventory and Analysis (FIA) Program. The percent areas comprised within each operational feature were multiplied by total clearcut areas in the Coastal Plain region so that erosion and sedimentation estimates could be expanded to a regional scale. Examination of the different levels of BMP implementation revealed estimated sedimentation rates of 0.5 Mg ha−1 yr−1 and 0.4 Mg ha−1 yr−1 at the BMP-standard and BMP+ levels, respectively. The range of overall estimated sediment masses at the BMP-standard and BMP+ levels most accurately reflects the current state of BMP application in the Coastal Plain. BMPs were most obviously effective at mitigating erosion and potential sediment delivery from Coastal Plain skid trails and haul roads. The highest level of BMP implementation (BMP+) at forest roads and skid trails mitigated approximately 95% of sediment compared to BMP–. Overall sediment removal efficiencies were 77% for BMP-standard and 83% for BMP+ respectively when compared to BMP–. Conclusively, this study demonstrates that forestry BMPs are highly effective at mitigating erosion and stream sedimentation when appropriately applied in the southeastern Coastal Plain.

Linkages between Forestry Best Management Practices and erosion in the southeastern U.S.

Numerous studies have concluded that forestry Best Management Practices (BMPs) are effective at mitigating erosion and sedimentation caused by forest operations; however, the complex relationship between forestry BMPs and erosion is largely unexamined. In this study, BMP implementation rates, which are percentages ranging from 0 to 100% that indicates how well an operator instituted recommended practices in the field, and predicted erosion rates, obtained by using USLE-Forest, were calculated for 108 recent harvests in twelve states and three physiographic regions in the southeastern U.S. BMP implementation rates were subdivided into three levels of application: BMP+ (>90% implementation), BMP-standard (80–90% implementation), and BMP− (<80% implementation). Skid trails (86.5 Mg ha−1 yr−1) and haul roads (90.3 Mg ha−1 yr−1) eroded at relatively high rates at the BMP− level across the southeast. This emphasizes the importance of adequate BMP measures such as utilizing water diversion structures and cover management at these features to better protect water quality. The overall weighted average erosion estimates for all regions at the BMP-standard (10.4 Mg ha−1 yr−1) and BMP+ (6.6 Mg ha−1 yr−1) levels were <11 Mg ha−1 yr−1, indicating that water quality and site productivity are largely protected when adequate BMPs are implemented, and Streamside Management Zones (SMZs) are utilized along streams. Approximately 94% of the sites sampled were classified as either BMP-standard or BMP+, demonstrating that BMPs are being implemented consistently throughout the southeast. Spearman ρ correlation analyses were performed for all variables. Forestry BMP implementation and erosion estimates had significant negative correlations, especially for skid trails (Spearman ρ = −0.59, p-value < 0.0001) and haul roads (Spearman ρ = −0.39, p-value = < 0.0001), as well as for all regions across the southeast. These variables, however, were poorly correlated for stream crossings, indicating that current audit questions in the southeast may not fully address erosion. Additionally, BMP implementation and erosion estimates exhibited a significant negative correlation (R2 = 0.28, p-value < 0.0001) based on a quadratic regression line for all features, reinforcing that as BMP implementation increases, predicted erosion generally decreases.

Relationship Between Riparian Buffers and Terrestrial Wildlife in the Eastern United States

Abstract When working forest stands are harvested, vegetated strips along streams are often retained as part of forestry best management practices (BMPs) to protect water quality. These riparian buffers, known as streamside management zones, when following forestry BMP recommendations, also likely provide benefits to various terrestrial wildlife species. To better understand the role of riparian buffers in contributing to biological diversity in working forest landscapes, we reviewed literature (n = 30) that reported on herpetofauna, bird, and mammal responses to riparian buffers in the eastern United States. Although few results were consistent among taxa, community composition commonly varied among riparian buffer widths. Narrower riparian buffers more commonly supported edge and disturbance-associated species whereas wider riparian buffers tended to support interior-associated species. We did not find a consistent width that supported all terrestrial wildlife species studied.

Estimated Sediment Protection Efficiences for Increasing Levels of Best Management Practices on Forest Harvests in the Piedmont, USA

In-stream watershed level evaluations confirm that application of recommended forestry best management practices (BMPs) can minimize sedimentation following management, while on-site erosion research shows that BMPs reduce erosion from individual forest operations, thus implying watershed-level sediment reductions. Assessments of forest operations and sediment have developed very few sediment delivery ratios (SDR). Linking BMP levels (low, standard recommendation, high) within specific forest operations to sedimentation could enable managers to evaluate BMP effects. Reported data regarding forest operations, erosion rates and SDR by forest operation, and BMP implementation levels were sufficient within the Piedmont region to allow approximations of sediment delivery and BMP efficiency. Existing United States Department of Agriculture (USDA) Forest Service reports and published erosion and sediment research were used to comprise the following method. For regional annual harvests, estimated sediment deliveries (Mg year−1) = annual harvest area (ha year−1) × weighted average erosion rate from all forest operations (Mg ha−1 year−1) × SDR (unitless ratio). Weighted average erosion rates for all forest operations were determined by applying areas in each operational activity (%) × estimated erosion per operation (Mg ha−1 year−1). In comparing published data, standard BMPs reduced estimated sedimentation by 75% compared to low BMP implementation levels. This supports forestry BMP efficiency findings reported for sediment removals in watershed studies. Higher levels of BMP implementation were estimated to potentially remove nearly all forest operation-produced sediment. Values of this pilot study should be viewed cautiously, as estimates were based on limited data, estimated operations, and limited SDRs; are based on BMP categories that vary between states; and address only one year following harvests. However, the approach provided approximations that facilitate BMP evaluations and can be improved with additional data. This methodology highlights the importance of accurate estimates of erosion rates, SDRs, sediment masses, and area for operations. This supports the importance of state programs, which have increased BMP implementation rates and compliance options with BMP program maturation.

The effectiveness of forestry best management practices at skidder stream crossings in Virginia

Sediment is the most common nonpoint source pollutant associated with timber harvesting in the southeastern United States. Sediment is of particular concern at operational stream crossings because sediment delivery potential is increased by stream proximity and any compromised streamside management zone buffers. This study quantifies the effectiveness of water quality best management practices (BMPs) implemented at operational skidder stream crossings in three physiographic regions of Virginia. We located 79 operational skid trail crossings and assessed implementation of state BMP manual recommendations, percentage positive response to a Virginia Department of Forestry BMP audit questionnaire, and potential soil erosion as predicted by the Universal Soil Loss Equation (USLE)-Forest methodology and Water Erosion Prediction Project: Road interface. Estimated erosion rates decreased with increasing BMP scores for skid trails (p

Effects of the sustainable forestry initiative fiber sourcing standard on the average implementation rate of forestry best management practices in Georgia, United States

Much of the discourse on the sustainability of forestry resources revolves around certified forestland. It is typically assumed that certified forestland is the hallmark of sustainable forestry. This reasoning has led to a general perception that uncertified forestlands are not sustainably managed. In this regard, the role of the Sustainable Forestry Initiative (SFI) Fiber Sourcing Standard is instrumental in promoting sustainable forest management on uncertified forestlands. We used an advanced spatial approach to determine the influence of the SFI Fiber Sourcing Standard over space and time on Georgia's forestlands. We also assessed differences in the implementation rate of forestry Best Management Practices (BMPs) in Georgia on harvested sites located within the sourcing radius of mills certified to SFI Fiber Sourcing Standard relative to those harvest sites located outside the sourcing radius of certified mills. Our results suggest that the SFI Fiber Sourcing Standard affects 80% or more of total forestland in Georgia. We also found that the average BMP implementation rate on harvested sites located within the sourcing radius (about 65 km) of certified mills is about 2% higher relative to harvested sites located outside the sourcing radius of such mills over time. Our results indicate that the SFI Fiber Sourcing Standard is helping in ensuring sustainability of forestlands in Georgia, as forestry BMPs are an important indicator of sustainable forest management. We hope our results will bring clarity to the overall sustainability of uncertified forestlands in Georgia and other forested regions in North America in the context of global private forest governance systems like the SFI Fiber Sourcing Standard.

Effects of selective forest harvesting best management practices on organic matter and invertebrate detritivores in streams draining subtropical eucalypt forest

Best management practices (BMPs) for forestry activities have been developed to mitigate the impacts of timber harvesting on stream ecosystems in New South Wales, Australia. These BMPs include selective harvesting within the catchment, exclusion of harvesting in riparian zones, and restrictions on harvesting and machinery operations during wet weather or on steep slopes. The few studies assessing the ecological effects of forestry BMPs have largely focussed on operations in temperate climates and are often based on a single pair of control and impact streams. But what are the effects in subtropical regions where climatic and hydrological variability may be greater? Are the effects of selective harvesting dependent on the proximity of harvesting to the locations of monitoring? We used a multiple paired-catchment study to assess effects of forestry BMPs on standing stocks of benthic coarse particulate organic matter (CPOM) and densities of invertebrate detritivores in streams draining subtropical eucalypt catchments that were either harvested using BMPs (‘impact’) or unharvested (‘control’). CPOM and detritivores in three pools in each of the four streams were sampled multiple times before and after the impact catchments were harvested. Harvesting intensity and proximity of harvesting to stream monitoring sites differed between ‘impact’ catchments. Benthic CPOM was dominated by leaves and leaf fragments in all streams. There were no post-harvesting differences in CPOM composition, standing stocks of different CPOM fractions or densities of detritivorous stream invertebrates in two feeding groups (collector-gatherers and shredders) between stream pairs despite differences in the proximity (minimum of ∼50 m and 1.6 km) of harvesting to monitoring sites. We conclude that relative to matched control sites, selective forestry BMPs do not alter CPOM stocks and stream detritivore densities in this subtropical Australian eucalypt forest, implying that these BMPs are effective in mitigating effects of harvesting across similar subtropical forests.

Environmental effects of short‐rotation woody crops for bioenergy: What is and isn't known

AbstractLogging and mill residues are currently the largest sources of woody biomass for bioenergy in the United States, but short‐rotation woody crops (SRWCs) are expected to become a larger contributor to biomass production, primarily on lands marginal for food production. However, there are very few studies on the environmental effects of SRWCs, and most have been conducted at stand rather than at watershed scales. In this manuscript, we review the potential environmental effects of SRWCs relative to current forestry or agricultural practices and best management practices (BMPs) in the southeast United States and identify priorities and constraints for monitoring and modeling these effects. Plot‐scale field studies and a watershed‐scale modeling study found improved water quality with SRWCs compared to agricultural crops. Further, a recent watershed‐scale experiment suggests that conventional forestry BMPs are sufficient to protect water quality from SRWC silvicultural activities, but the duration of these studies is short with respect to travel times of groundwater transporting nitrate to streams. While the effects of SRWC production on carbon (C) and water budgets depend on both soil properties and previous land management, woody crops will typically sequester more C when compared with agricultural crops. The overall C offset by SRWCs will depend on a variety of management practices, the number of rotations, and climate. Effects of SRWCs on biodiversity, especially aquatic organisms, are not well studied, but a meta‐analysis found that bird and mammal biodiversity is lower in SRWC stands than unmanaged forests. Long‐term (i.e., over multiple rotations) water quality, water use, C dynamics, and soil quality studies are needed, as are larger‐scale (i.e., landscape scale) biodiversity studies, to evaluate the potential effects of SRWC production. Such research should couple field measurement and modeling approaches due to the temporal (i.e., multiple rotations) and spatial (i.e., heterogeneous landscape) scaling issues involved with SRWC production.

Understanding perceptions of stakeholder groups about Forestry Best Management Practices in Georgia

Forestry Best Management Practices (BMPs) are critical in ensuring sustainable forest management in the United States because of their effectiveness in protecting water quality, reducing soil erosion, maintaining riparian habitat, and sustaining site productivity. The success of forestry BMPs depends heavily on coordination among primary stakeholder groups. It is important to understand perceptions of such groups for a successful forest policy formulation. We used the SWOT-AHP (Strengths, Weaknesses, Opportunities, and Threats analysis with the Analytical Hierarchy Process) framework to assess perceptions of three stakeholder groups (loggers, landowners, agency foresters) about forestry BMPs in Georgia, the largest roundwood producing state in the United States. The agency and logger stakeholder groups gave the highest priority to improved reputation under the strength category, whereas the landowner stakeholder group perceived sustainable forestry as the highest priority under the same category. Lack of landowner education was the highest priority under the weakness category for landowner and agency stakeholder groups, whereas the logger stakeholder group selected lack of trained personnel as the highest priority under the same category. Agency and landowner stakeholder groups gave the highest priority to training and education while loggers indicated maintenance of forest-based environmental benefits as their highest priority under the opportunity category. Finally, landowners and agency stakeholder groups perceived more regulations and restrictions as most significant in the threat category whereas the logger stakeholder group was most concerned about the insufficient accounting of cost sharing under the same category. Overall, selected stakeholder groups recognize the importance of forestry BMPs and had positive perceptions about them. A collaborative approach based on continuous feedback can streamline expectations of stakeholder groups about forestry BMPs in Georgia and several other states that are interested in maintaining high compliance rate of forestry BMPs for ensuring sustainable forest management.

Assessing effectiveness of long-term forestry best management practices on stream water quality at a basin scale-a case study in Southern USA.

Forestry best management practices (BMPs) have proven to be very effective in protecting adjacent stream water quality at the plot scale. However, our knowledge is incomplete about the effectiveness of forestry BMPs in large watersheds where industrial forests are intensively managed. In this study, we compared long-term concentrations and loadings of total suspended solids (TSS), nitrate/nitrite nitrogen (NO3NO2-N), total Kjeldahl nitrogen (TKN), and total phosphorus (TP) before (1978-1988) and after extensive implementation of forestry BMPs (1994-2008) at the outlet of a 5000-km2 riverbasin that is predominately covered by intensively managed pine forests in Central Louisiana, USA. Our study shows that after extensive BMP implementation, both concentrations and loads of TSS in the basin outlet decreased significantly from 34 to 25mgL-1 and from 55,000 to 36,700tyear-1, respectively. However, no significant difference was found in NO3NO2-N, TKN, and TP concentrations between the two periods. The results of nutrient loadings varied, whereby the annual nitrogen loading declined without significant differences (from 1790 to 1600tyear-1 for TKN and from 176 to 158tyear-1 for NO3NO2-N, respectively) but the annual TP loading increased significantly (from 152 to 192tyear-1) after BMP implementation. Theincrease in TP loading is likely due to an increased application of phosphorus fertilizer, which offset BMPs' effects especially during high-flow conditions. These results strongly suggest that current forestry BMPs in this region are effective in reducing sediment loading, but current BMP guidelines for fertilization and nutrient management need to be reviewed and improved.

Forestry Best Management Practices Relationships with Aquatic and Riparian Fauna: A Review

Forestry best management practices (BMPs) were developed to minimize water pollution from forestry operations by primarily addressing sediment and sediment transport, which is the leading source of pollution from silviculture. Implementation of water quality BMPs may also benefit riparian and aquatic wildlife, although wildlife benefits were not driving forces for BMP development. Therefore, we reviewed literature regarding potential contributions of sediment-reducing BMPs to conservation of riparian and aquatic wildlife, while realizing that BMPs also minimize thermal, nutrient, and chemical pollution. We reached five important conclusions: (1) a significant body of research confirms that forestry BMPs contribute to the protection of water quality and riparian forest structure; (2) data-specific relationships between forestry BMPs and reviewed species are limited; (3) forestry BMPs for forest road construction and maintenance, skid trails, stream crossings, and streamside management zones (SMZs) are important particularly for protection of water quality and aquatic species; (4) stream crossings should be carefully selected and installed to minimize sediment inputs and stream channel alterations; and (5) SMZs promote retention of older-age riparian habitat with benefits extending from water bodies to surrounding uplands. Overall, BMPs developed for protection of water quality should benefit a variety of riparian and aquatic species that are sensitive to changes in water quality or forest structure.

National status of state developed and implemented forestry best management practices for protecting water quality in the United States

United States forestry best management practices (BMPs) were developed by U.S. states to protect water quality while enhancing the sustainability of forest management activities. Forestry BMPs are revised over time or new BMPs are written to meet current water quality standards. Properly implemented forestry BMPs have been found to minimize the impact of erosion and sediment that may occur during forest management activities. States developed implementation strategies to help determine if BMPs are being implemented correctly; however, these strategies can vary between regions and states making implementation results difficult to interpret. Few studies have compared monitoring strategies and implementation of BMPs on a national level. This study surveyed and received responses from state forestry agencies in all 50 states. Each state reported a documented BMP manual. Twenty states reported non-regulatory BMP guidelines, 19 reported quasi-regulatory BMP guidelines, and 11 reported regulatory BMP guidelines. Thirty-nine states have BMP monitoring programs with the state forestry agency as the lead agency in 35 states. BMP effectiveness studies were reported in 33 states with 19 states reporting current or future effectiveness studies. Thirty-two states reported that they have conducted BMP implementation studies resulting in a mean national BMP implementation rate of 91%. However, when evaluating implementation of individual BMP categories, the survey indicated potential deficiencies for some states, yet these states’ overall BMP implementation rate appear to be satisfactory. There was no significant difference between non-regulatory, quasi-regulatory, and regulatory BMP guidelines when compared by mean state BMP implementation rates (90.2%, 90.2%, and 93.4%, respectively). Mean BMP implementation rates for the western (93.2%) and southeastern (92.4%) regions were significantly higher than the northeastern region (86.4%). This assessment of state BMP programs indicates that BMP programs appear to be implemented at relatively high levels across the U.S. These findings should be useful globally for agency managers to improve program effectiveness and better understand BMP implementation and program structure among 50 diverse states.

Water quality effects of short-rotation pine management for bioenergy feedstocks in the southeastern United States

Growing interest in renewable and domestically produced energy motivates the evaluation of woody bioenergy feedstock production. In the southeastern U.S., woody feedstock plantations, primarily of loblolly pine (Pinus taeda), would be intensively managed over short rotations (10–12years) to achieve high yields. The primary differences in managing woody feedstocks for bioenergy production vs for pulp/sawtimber production include a higher frequency of pesticide and fertilizer applications, whole-tree removal, and greater ground disturbance (i.e., more bare ground during stand establishment and more frequent disturbance). While the effects of pulp/sawtimber production on water quality are well-studied, the effects of growing short-rotation loblolly pine on water quality and the efficacy of current forestry Best Management Practices (BMPs) have not been evaluated for this emerging management system. We used a watershed-scale experiment in a before-after, control-impact design to evaluate the effects of growing loblolly pine for bioenergy on water quality in the Upper Coastal Plain of the southeastern U.S. Intensive management for bioenergy production and implementation of current forestry BMPs occurred on ∼50% of two treatment watersheds, with one reference watershed in a minimally managed pine forest. Water quality metrics (nutrient and pesticide concentrations) were measured in stream water, groundwater, and interflow (i.e., shallow subsurface flow) for a two-year pre-treatment period, and for 3.5years post-treatment. After 3.5years, there was little change to stream water quality. We observed a few occurrences of saturated overland flow, but sediments and water dissipated within the streamside management zones in over 75% of these instances. Stream nutrient concentrations were low and temporal changes mainly reflected seasonal patterns in nitrogen cycling. Nitrate concentrations increased in groundwater post-treatment to <2mgNL−1, and these concentrations were below the U.S. drinking water standard (10mgNL−1). Applied pesticides were almost always below detection in streams and groundwater. Overall, these findings highlight that current forestry BMPs can protect stream water quality from intensive pine management for bioenergy in the first 3.5years. However, groundwater quality and transit times need to be considered in these low-gradient watersheds of the southeastern U.S. that are likely to become an important location for woody bioenergy feedstock production.

Best Management Practices for Low-Volume Forest Roads in the Piedmont Region

Forest roads provide important access for forest management activities, yet those roads, skid trails, and stream crossings have repeatedly been reported as major sources of sediment. The passage of the Federal Water Pollution Control Act of 1972 focused considerable research on the development of forestry best management practices (BMPs) for reducing sediment input from forest roads. Recent litigation in the U.S. Supreme Court has reemphasized the importance of enhancing BMPs for forest roads. This paper synthesizes and interprets two decades of applied research on BMPs for low-volume forest roads, with emphasis on research conducted on forest operations in the Virginia Piedmont region. BMP interpretations include (a) current BMP status for forest roads, skid trails, and stream crossings; (b) advantages of preharvest planning; (c) forest road design; (d) forest road closure; (e) recommended BMPs for legacy roads; (f) guidelines for minimizing area of forest roads; (g) deck and skid trail rehabilitation; (h) closure of bladed and overland skid trails; (i) alternative harvest systems; (j) permanent and temporary closure of the stream crossing; (k) selection of stream crossing types; and (l) recommendations for streamside management zones. Major conclusions from this synthesis are that forest roads, skid trails, and stream crossings continue to be ranked as problem sources of sediment, but forestry BMPs can be used to reduce sediment inputs from such areas. Problems with road and skid trails can generally be attributed to poor planning and insufficient quantity or quality of BMPs.

The Effectiveness of Forestry Best Management Practices for Sediment Control in the Southeastern United States: A Literature Review

Abstract Water quality from forested watersheds (both managed and unmanaged) is normally very good and better than most other human-dominated land uses. Water degradation is possible during forestry operations; however, the use of best management practices (BMP) has been shown to substantially reduce the risk. In the southeastern United States, forests are managed under a wide range of conditions reflective of physiographic region, soil erodibility, climate, and site wetness. Although it is clear that BMP reduce sediment and pollutant loading into streams, there is less information regarding how effective these practices are (i.e., how much sediment did BMP retain? What was the mechanism for sediment retention?). A review of the scientific literature was conducted to evaluate forestry BMP effectiveness to control sediment in the southeastern United States. Our reviewly quantified BMP effectiveness to reduce sediment. In the Coastal Plain, research has focused on forest roads and site wetness, whereas in the Piedmont and regions with steeper terrain, the focus has been on streamside management zones. These studies provide an initial indication of how much sediment is reduced by BMP; however, more information is needed for managers to make reasonable estimations. Future research should focus on quantifying BMP effects on sediment yield and identifying the specific mechanisms involved.

Harvest, Site Preparation, and Firebreak Effects on Hydrology and Sediment Transport in Coastal Plain Headwater Streams

The Dry Creek paired watershed study was conducted to evaluate the effectiveness of modern southeastern forestry best management practices (BMPs) by observing hydrology and sediment transport in four southwest Georgia headwater streams during pre-harvest, post-harvest, and post-site preparation (post-prep) periods. After collecting two years of baseline data on all four streams, two of the watersheds were harvested in accordance with the Georgia Forestry Commission's 1999 BMPs. Downstream sections of streamside management zones (SMZs) were partially harvested to the maximum extent allowable by BMP guidelines of 11.5 m2 ha-1 (50 ft2 acre-1) of remaining basal area, while upstream sections remained unthinned. Treatment data collection consisted of a one-year post-harvest period and a two-year post-prep period. After harvest, water yields increased by 92 to 267 mm year-1 and groundwater tables rose, as evidenced by the immediate appearance of toe-slope seeps in the treatment watersheds. Peak flow behavior displayed large variation among storm events and between watersheds but did not significantly change after harvest. Total suspended solid (TSS) yields and inorganic suspended solid (ISS) concentrations were variable across watersheds and years but did not reveal significant effects as a result of harvest or site preparation. Firebreaks plowed around the SMZs were an area of concern for sediment production. Occurrences of concentrated overland flow entering SMZs and streams increased in the treatment watersheds immediately after harvest but decreased to pretreatment levels within two years following harvest. Modern forestry BMPs were effective in preventing sediment increases due to harvest and site preparation within the studied streams.

Trends for Forestry Best Management Practices Implementation

Abstract The 1972 Clean Water Act initiated a national effort to address all sources of water pollution. One outcome was development of forestry nonpoint source control programs that use best management practices (BMP) and other tools to minimize water quality impacts. These programs can only be successful if BMPs are effective and if implementation rates are high. Many states have assessed rates of forestry BMP implementation with more than one survey and are beginning to develop histories that track trends. Trend data at the regional and national levels show generally high and increasing levels of implementation. Here, we use the volume of timber harvested in each state to adjust contributions to a national implementation average. The overall national forestry BMP implementation rate is estimated to be 89%. Factors contributing to increased implementation include federal and state legislation, regulation, and extension; certification programs; and public pressure.

Efficiencies of Forestry Best Management Practices for Reducing Sediment and Nutrient Losses in the Eastern United States

Abstract Quantifying the effects of forestry best management practices (BMPs) on sediment and nutrient loads is a critical need. Through an exhaustive literature search, three paired forested watershed studies in the eastern United States were found that permitted the calculation of BMP efficiencies—the percent reduction in sediment or nutrients achieved by BMPs. For sediment, BMP efficiencies ranged from 53 to 94% during harvest and up to 1 year after harvesting. For nutrients, BMP efficiencies were higher for total nitrogen (60-80%) and phosphorus (85-86%), which included particulate and sediment-bound forms, than for nitrate-nitrogen (12%), which occurs primarily in the dissolved phase. Results indicate forestry BMPs can significantly reduce sediment and nutrient loads; however, BMPs appear to be more effective at reducing pollutants associated with surface runoff than with subsurface flow.