Agricultural Commodity Prices

Thompson, Robert Stanley North Carolina State University ProQuest Dissertat 2021 해외박사(DDOD)

The two essays of this dissertation investigate the determinants of agricultural commodity prices, more specifically those for field crops. Risk is a common theme in agriculture, largely due to the nature of agriculture itself. Farmers make large investments throughout the growing season without knowing with certainty the prices for which they will sell their crop, the size of which is also subject to uncertainty. Those with obligations to purchase these agricultural commodities also face these risks. It is important to develop forecasts of the range of prices and quantities buyers and sellers can expect to receive in the future and the probability those prices and quantities are realized. An investigation into the underlying structure of these markets facilitates the development of these forecasts in a manner consistent with basic economics. Chapter one and two are different applications of the same general approach to developing forecasts. Development of forecasting methods begin with simple theoretical models of the market of interest. Simple theoretical frameworks give the forecaster general direction that can be refined further to add certain market nuances conditional on the amount of information available for model estimation.The goal of chapter one is to accurately characterize planting time forecasts of the joint distribution of price and yield at harvest. It is common practice to derive this joint distribution with a disjoint set of methods that are almost entirely data driven. I use a system of supply and demand to show potential problems that arise with these status quo methods and propose solutions to those problems. The result is the derivation of the joint distribution of price and yield that is consistent with a given market structure. I repeat this exercise with several small changes to the system of supply and demand – each of which comes with its own set of limiting assumptions.Chapter two is an investigation into the primary determinants of corn prices in North Carolina. North Carolina is a corn deficit state. The large amount of feed required to feed the hogs, broilers, and turkeys in North Carolina exceeds the amount produced here, so a large amount must be imported from outside sources. Reliable forecasts of corn prices are useful for informing marketing decisions for buyers and sellers of corn in North Carolina. There is a large literature about forecasting local corn prices. However, much of that research focuses on regions that are not similar to the market in North Carolina and it is uncertain whether results found elsewhere are applicable to the grain deficit state of North Carolina. I first investigate the underlying structure of the market in North Carolina. Then, I test some conventional methods for forecasting accuracy and compare the results to novel methods developed based on the specific market structure in North Carolina.

Mortality and Movement of Spotted Seatrout at Its Northern Latitudinal Limits

Ellis, Timothy Alan North Carolina State University 2014 해외박사(DDOD)

Spotted seatrout (Cynoscion nebulosus) is one of the most economically important sportfish in the U.S. South Atlantic and Gulf of Mexico. The species is uncommon north of Chesapeake Bay but supports large recreational and commercial fisheries in North Carolina and Virginia. However, despite its importance, relatively little is known about spotted seatrout mortality and movement at the species' northern latitudinal limits, including winterkill and the appropriate spatial scale for management. Data from the first comprehensive tag-return study (i.e., high-reward and double tagging) of spotted seatrout in North Carolina were used to estimate bimonthly rates of fishing mortality (F) and natural mortality (M). From September 2008 to October 2012, 6,582 spotted seatrout were tagged and 557 (8.5%) tags were recovered and reported by fishers through August 2014. Estimates of bimonthly F and M varied seasonally and ranged from 0.024-0.139 and 0.062-2.527, respectively. Contrary to findings from North Carolina's recent age-based stock assessment, annual mortality from natural causes was always identified to be much higher than mortality from fishing. In a concurrent telemetry study, spotted seatrout in two North Carolina estuaries were tagged with acoustic transmitters and monitored during three consecutive winters of varying severity. Fates of telemetered fish were inferred from daily movements and used in a multistate capture-recapture model to estimate weekly F, M, and emigration rate. Again, fishing mortality was found to be low relative to natural mortality during most weeks with few inferred harvests of telemetered fish (weekly estimates of F ranged from 0.012-0.078) and more natural deaths (weekly M ranged from 0.012-0.300); most natural deaths occurred when water temperature was below 5 °C. Field estimates of M were supported by the results of two laboratory experiments on the cold tolerance of spotted seatrout, as affected by rapid and prolonged exposure to low-temperature extremes (3, 5, or 7 °C) across upper- (10 ‰) and lower-estuarine (30 ‰) salinities. These empirical estimates of cold tolerance were used to develop temperature-based models for predicting winter M, which were then applied to 1994 to 2013 water temperature data. Estimates of winter M from the last 20 years that were high matched historical winterkill events. Lastly, tag recovery information was used to describe the large-scale movements of spotted seatrout in North Carolina. Regional differences in movement suggest that most spotted seatrout reside year-round within the major estuarine systems of North Carolina but that fish tagged in the northern Outer Banks region tend to be transient. For reported recaptures of spotted seatrout tagged in North Carolina (n = 499), 49 (9.8%) were from outside of the state's jurisdictional boundaries, primarily Chesapeake Bay. Extensive movements southward during fall months and northward during spring and summer months are likely associated with known overwintering and spawning periods for spotted seatrout. In combination, these studies provide much new information about spotted seatrout ecology, stock boundaries, and the relative importance of fishing and natural morality, which will improve future management of this species throughout its geographic range.

Methods for Monitoring and Assessing Sturgeon Populations Using Technology

Flowers, Henry Jared North Carolina State University 2015 해외박사(DDOD)

Sturgeons (Acipenseridae) are one of the most threatened taxa worldwide, including populations of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus. This subspecies is found in rivers and marine areas of the Atlantic Coast of the United States. The National Oceanic and Atmospheric Administration listed Atlantic Sturgeon under the Endangered Species Act in 2012. The listing delineated five Distinct Population Segments (DPS), one classified as threatened (Gulf of Maine) and five as endangered (New York Bight, Chesapeake Bay, Carolina, and South Atlantic). Populations are significantly reduced from historic levels by a combination of intense fishing and habitat loss. Successful restoration of Atlantic Sturgeon depends on a solid foundation of biological data. Traditional fisheries sampling approaches are often limited for federally-listed species such as Atlantic Sturgeon. One alternative is to develop less-intrusive methods using new technologies. Side-scan sonar is an emerging fisheries technology with advantages over traditional sampling techniques, including the ability to efficiently sample large areas and survey fish without physically handling them -- important for species of conservation concern. Acoustic telemetry is another area of rapid technological advances, including smaller, longer-lived tags and new designs for submersible receivers. Online databases facilitate data-sharing between researchers operating autonomous receiver arrays, enabling telemetry studies to incorporate expansive spatial areas. The first objective for this study was to develop methodology using side-scan sonar to survey and assess Atlantic Sturgeon populations. This was accomplished by surveying six North and South Carolina rivers, using a combination of side-scan sonar, telemetry, and video cameras (to sample jumping sturgeon). We surveyed lower reaches of each river, near the saltwater/freshwater interface, on three occasions (generally successive days) and used occupancy modeling to analyze these data. We were able to detect sturgeon in five of six rivers, with estimated gear-specific detection probabilities ranging from 0.2-0.5 and riverspecific occupancy estimates (per 2-km river segment) ranging from 0.0-0.8. Next we used count data from the same side-scan sonar surveys to estimate abundances of sturgeon >1 m in length in conjunction with N-mixture and distance models. Estimated abundances in the Carolina DPS were 2,031 (95% confidence interval: 1,075- 3,858) and 1,912 (1,016-3,616) using N-mixture and distance models, respectively. The Pee Dee River, South Carolina had the highest overall abundance of any river at 1,944 (1,036- 3,646) and 1,823 (976-3,406) using count and distance models, respectively. These estimates do not account for sturgeon occurring in unsurveyed riverine reaches or marine waters. Comparing the two models, the N-mixture model produced similar estimates using less data than the distance model with only a slight reduction of estimated precision. The third objective was to use telemetry to describe long-term movements of Atlantic Sturgeon from the Roanoke River, North Carolina. Six adult Atlantic Sturgeon (presumably males) were implanted with acoustic telemetry tags from 2010-2012. Sturgeon were monitored through a network of passive receivers in North Carolina and eight additional states. A multi-state model was used to estimate movement probabilities among riverine, estuarine, and marine areas. From September 2010 to June 2014, five of six Atlantic Sturgeon were detected in marine portions of three different DPSs. Seasonally, sturgeon were observed to either spend the entire year in marine waters or winter-spring in marine waters, summer in Albemarle Sound and fall in the Roanoke River for spawning. The multistate model suggests seasonally variable movement probabilities. Estimated annual mortality was relatively low (0.03) and detection probability high (>0.50) in most study regions. Sturgeon were observed to spawn in consecutive years or with a year in between spawning events. The complexity of Atlantic Sturgeon movements and the mixing of populations in marine waters add to the potential difficulty in managing the recovery of this species.

Evaluation of Herbal Oils in Various Preparations for Treating Mastitis in Dairy Cattle

Mullen, Keena Ann Elizabeth North Carolina State University 2013 해외박사(DDOD)

The organic dairy industry is growing rapidly in the United States and with its growth is an increasing need for organic treatments for mastitis. Mastitis, or udder inflammation, is often caused by bacterial infection and is conventionally treated with antibiotics. Antibiotics are also used at the end of lactation, known as dry cow therapy, to eliminate existing intramammary infections and prevent new infections from occurring before the next lactation. Organic dairies in the United States are prohibited from using antibiotics in their cattle and thus use alternatives for mitigating mastitis. Mastitis can be measured through culturing milk of cows or measuring the somatic cell count of the milk, which is an indicator of the level of inflammation present and is often transformed into a linear score (SCS). No research has been performed comparing organic and conventional dairies in the southeast where heat and humidity make quality milk production challenging. The goals of the research contained in this dissertation were to compare milk quality on organic and conventional dairies in the southeastern United States and to evaluate two herbal alternatives to antibiotics for use as dry cow therapy. In the first experiment, organic and conventional dairies in North Carolina were compared during the warm months. Seven organically and 7 conventionally managed dairy herds in North Carolina were surveyed in 2010 to record differences in milking procedures, mastitis detection and treatment, and to determine the prevalence of mastitis-causing organisms and milk quality for each management type. Overall infection rate, SCS, and cowlevel prevalence of several mastitis-causing pathogens were not different between organic and conventional dairies surveyed. Because of the similar prevalence of mastitis-causing organisms in organic and conventional dairies in North Carolina, further studies were planned to evaluate alternatives to antibiotics for mastitis mitigation. The second experiment evaluated two commercially available alternatives to antibiotics as dry cow therapy on organic and conventional dairies. Phyto-Mast RTM and Cinnatube(TM) are two intramammary products composed primarily of plant-based oils. In a study comparing Phyto-Mast, Cinnatube, Phyto-Mast and Cinnatube, no treatment, and conventional antibiotic and teat sealant dry cow therapy, the herbal products had no negative effects on milk production or SCS and similar cure and new infection rates to the cows receiving conventional dry cow therapy and the untreated cows. However, the cure rate was difficult to assess and compare because of a low initial infection rate. The potential of Phyto-Mast to cure infections was investigated in the third experiment by testing the antibacterial activity of each of its plant-derived oil ingredients, alone and in combination, in vitro against 3 mastitis-causing pathogens in milk. Only essential oil of Thymus vulgaris (thyme) had a consistently significant antibacterial effect. The fourth experiment examined Phyto-Mast again as a dry cow therapy, this time compared with an internal teat sealant, the combination of Phyto-Mast and internal teat sealant, and no dry cow therapy to determine if an internal teat sealant had any effect on the efficacy of Phyto-Mast. Though the SCS and cure rates of cows receiving either Phyto-Mast, teat sealant, a combination of the two, or no treatment were not different among treatments, the combination of Phyto-Mast and teat sealant had significantly fewer new infections than no treatment. Taken altogether, there is a need for alternatives to antibiotics for organic dairy producers throughout the United States. The herbal treatments tested here did not negatively affect milk production or SCS, and were not inferior to conventional dry cow therapy for preventing new infections from occurring during the dry period. Thyme oil, an ingredient of one of the herbal treatments, has significant antibacterial activity when cultured in milk.

Modeling water flow to drains in flat, poorly drained lands

Salem, Hany El-Sadany North Carolina State University 2000 해외박사(DDOD)

Models that are based on numerical solutions to the two-dimensional Richards equation are considered the most accurate method for modeling water flow towards drains. However, input data sets are difficult to obtain and application of these models to certain combinations of soils and boundary conditions may result in numerical difficulties. In this study the different methods that are used to describe flow towards drains are critically examined with the aim of identifying or developing relatively simple methods of describing the drainage processes. The model SWMS_2D, which is based on finite element solutions to the Richards equation, was used as basis of comparison for evaluating other models that are based on solutions to the Boussinesq equation and models based on successive steady state approximation. Solutions were obtained and the models evaluated for different combinations of soils and drainage system parameters. Numerical solutions to the Richards equation show that flow is two dimensional with the vertical component dominant when water table is close to the soil surface. Flow is mostly horizontal for deeper water table conditions, except for the area near the drain where flow is approximately radial. Solutions to the Boussinesq equation for constant drainable porosity values failed to match those produced by solutions to the two-dimensional Richards equation along the whole solution range. Solutions to the Boussinesq equation that consider a variable drainable porosity and correct for convergence using the equivalent depth method underestimated water table drawdown at the midpoint as well as cumulative drainage. Solutions to the Boussinesq equation with a variable drainable porosity overestimated water table drawdown near the midpoint when the radial flow concept was used as a drain boundary condition. However, this method of solution gave results that were closer to solutions to the Richards equation than the other approximate methods considered. A mass balance method that uses combination of Hooghoudt equation and Kirkham solution to predict drainage rates overestimated water table drawdown at the midpoint during the early stage when water table is standing above the drain at the drain. During the same stage, the mass balance approach underestimates drainage rates. Steady state drainage equations are often used to predict drainage rates in models that simulate transient processes. Several steady state equations for drainage to parallel drains were reviewed and evaluated. Relationships between drainage rate and water table elevation at the midpoint between drains, as predicted by the steady state equations are compared to finite element solutions to the Richards equation for both transient and steady state events. When the water table midway between drains is close to the soil surface, the water table elevation at the drain is higher for the transient condition than for the steady state condition. For such conditions, solutions to the steady state condition underestimates the drainage rate-water table elevation relationship q(m) as compared to solutions to the transient conditions. For deeper water table conditions, water table profiles and drainage rates predicted by solutions for steady state and transient conditions were in close agreement. The q(m) relationship predicted by the Hooghoudt equation was always in excellent agreement with the finite element solutions for steady state conditions. An algorithm for predicting drainage rates in terms of average water table elevation was developed. The algorithm, which combines classical solutions by Kirkham for ponded conditions, the Hooghoudt equation for drawdown conditions and an empirical equation for the transition, was tested for conventional and controlled drainage conditions. The new algorithm can be used to predict drainage rates for water table conditions ranging from drain level to a fully saturated profile with ponded surface. Numerical solutions to the two-dimensional Richards equation (SWMS_2D) was used to describe flow rates, water table draw down and hydraulic head for an experimental site in eastern North Carolina. Measurements showed that the water table frequently rose to the surface following intense rainfall events. High head losses near the drain were evident even when the water table was below the soil surface. Predicted and measured results were compared for several hydrologic events. The measured soil parameters had to be adjusted in order to achieve agreement between measured and simulated results. Measured and simulated cumulative drainage and water table draw down were in good agreement except for the zone near the drain. Effects of a sand envelope material and drain trench backfill, both with hydraulic conductivity greater than the surrounding soil, were studied. Numerical simulations showed that high conductivity zones near the drain resulted in slight acceleration of drainage and water table draw down near the drain.

A vision of an open door: The establishment and expansion of the North Carolina community college system

Wescott, Joseph Warren, II North Carolina State University 2005 해외박사(DDOD)

After World War II, university extension centers and public junior colleges preceded the establishment of noncomprehensive community colleges and industrial education centers in 1957. In the establishment of these institutions and the passage of enabling legislation and funding for the industrial education centers in that year is the earliest beginning of the community college system in North Carolina. The decision to build and maintain these centers grew from the great need for education beyond the high school, a need that was not being met by North Carolina's public and private colleges and the desire to provide the state with a well-trained workforce to support the new industries being attracted to the state. Throughout their development and operation, the industrial education centers would be at the center of a controversy over how best to accomplish these goals. Yet their success in opening doors of opportunity to the state's disadvantaged adults and vocationally inclined high school students laid a foundation for the development of a system of comprehensive community colleges in 1963. With the election of a new governor, Terry Sanford, and the passage of the Omnibus Higher Education Act in 1963, the vision of a comprehensive community college system became a reality. The growth of the new system was phenomenal, especially in the turbulent era of the Sixties. The number of colleges doubled and the student population increased over 400 percent from 1963 until 1970. By 1970, the final year in our study, the value of the community college system in providing greater access to higher education for all residents of North Carolina was well established and recognized by the state's leaders and citizens alike.

Experimental investigation of suspended droplet evaporation in a turbulent free-stream

Dale, Crystal Buchanan North Carolina State University 2000 해외박사(DDOD)

Experiments have been performed investigating the effect of gas-phase turbulence on the evaporative heat and mass transfer of suspended heptane droplets. Comparisons are made to previously established correlations relating heat transfer and evaporation rate to characteristic flow properties such as Reynolds number, mass transfer number, and turbulence intensity. A previously developed heat transfer correlation (Yearling (1995)) accounts for gas phase turbulence level as follows,<display-math> <fd> <fl><rm>Nu<inf>f</inf></rm><fen lp="par">1+<rm>B<inf>H,f</inf> </rm><rp post="par"></fen>^0.7=2+0.58<hsp sp="0.212"> <rm>Re^1/2<inf>M</inf></rm><rm>Pr^1/3<inf> f</inf></rm><fen lp="sqb">1+0.07<hsp sp="0.212"><rm>TI^{0. 843}</rm><rp post="sqb"></fen></fl> </fd> </display-math>for the ranges,<display-math> <fd> <fl>100<<rm>Re<inf><rm>M</rm></inf></rm><1500,<hsp sp="0.212"> 0.7<<rm>Pr<inf><rm>mix,f</rm></inf></rm><1.0,<hsp sp="0.212"> 0<<rm>B<inf><rm>H,f</rm></inf></rm><0.1.</fl> </fd> </display-math>The convective heat transfer correlation degenerates to the laminar form in the absence of turbulence <display-math> <fd> <fl><rm>Nu<inf>f</inf></rm><fen lp="par">1+<rm>B<inf>H,f</inf> </rm><rp post="par"></fen>^0.7=2+0.58<hsp sp="0.212"> <rm>Re^1/2<inf><rm>M</rm></inf></rm><rm>Pr^1/3<inf> <rm>f</rm></inf></rm>.</fl> </fd> </display-math>. Experiments were conducted at the Applied Energy Research Laboratory (AERL) at North Carolina State University. The AERL test facilities consist of a heated wind-tunnel capable of producing a range of mean flow velocities (0.5 to 7 m/s), grid-generated turbulent integral length scales (2 to 7 mm), and turbulence intensities (0.6% with no grid to 15% with grid installed). Flow velocity and turbulence characteristics are determined using a one-component laser Doppler velocimetry (LDV) system. The droplet evaporation rate equated with the supplied mass-flow rate necessary to maintain a constant diameter (volume) droplet. The supply flow rate is directly measured using a precision syringe pump. Previous investigations at AERL (Yearling (1995)) have indicated that mild free-stream turbulence enhances heat transfer by as much as 30 to 50% over laminar free-stream conditions. The goal of this investigation is to quantify the interaction between the free stream turbulence structure and the evaporating droplet. A primary objective of the current investigation is to probe the validity of Yearling's turbulent correlation over a broader range of free-stream flow conditions. Experimental data is presented for laminar and turbulent free-stream over a Reynolds number range of 75 < Re < 320 and blowing regime range of 0.038 < B_H < to 0.141. Although good agreement has been found with the established laminar correlation, the heat transfer data in turbulent free-stream conditions did not indicate augmentation over laminar to the extent predicted. The effects of an in-situ droplet temperature measurement, droplet support system, internal circulation and downstream wake structure are considered and discussed. Results indicate that the free-stream turbulence strongly influences the droplet wake energy and structure.

Mating disruption for control of the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), in North Carolina apple orchards

Kovanci, Orkun Baris North Carolina State University 2003 해외박사(DDOD)

Oriental fruit moth, <italic>Grapholita molesta</italic> (Busck), has been a primary pest of peaches for many years throughout the world, and recently it has also emerged as a key pest of apples in the eastern United States. The implementation of the Food Quality Protection Act has eliminated the use of many organophosphate insecticides and encouraged the search for alternatives to organophosphates for control of Oriental fruit moth. Large and small plot studies were conducted to evaluate mating disruption as an alternative control tactic against Oriental fruit moth in North Carolina apple orchards during 2000–2002. The efficacy of Isomate-M 100 pheromone dispensers and microencapsulated sprayable pheromone were compared to insecticide-treated and non-managed blocks. Pheromone trap catches were significantly reduced in mating disruption blocks compared with conventional and non-managed orchards. Pheromone traps placed in the upper canopy captured significantly more moths than traps placed in the lower canopy across all treatments. Male OFM responded optimally to traps baited with 100 μg lures compared with 30 and 300 μg lures regardless of treatment. The loss of OFM pheromone from red rubber septa over a four-wk period exhibited a first-order release rate for septa loaded with 100 and 300 μg pheromone, but a more constant release rate from septa loaded with 30 μg pheromone. Based on pheromone trap captures, there was little difference among rates of sprayable pheromone ranging from 12.4 to 49.1 g (ai)/ha, but efficacy declined at 2.4 g (ai)/ha applied at monthly intervals. The 6.2 g (ai)/ha rate applied at 2-wk intervals was significantly less effective than monthly applications of 12.4 and 24.7 g (ai)/ha. Significantly fewer moths were caught in pheromone traps deployed in blocks treated in late May with Isomate-M 100, Isomate-M Rosso and Isomate-M 100 plus 3M sprayable pheromone compared with traps in conventional insecticide treatments, and Isomate-M 100 applied in late June. Overall, fruit damage by OFM larvae was quite low in mating disruption blocks.

Prisons in the Popular Mind: Historic Carceral Tourism and the Carceral State

Tewell, Megan Nye Cullen North Carolina State University ProQuest Dissertat 2020 해외박사(DDOD)

In the late twentieth century, historic carceral tourism emerged as a widespread and popular pastime in the United States, with thousands of visitors flocking each year to decommissioned jails, detention centers, and state and federal prisons. “Prisons in the Popular Mind” analyzes historic carceral tourism at the Ohio State Reformatory, the West Virginia Penitentiary, the Missouri State Penitentiary, the Old Joliet Prison, the Old Idaho Penitentiary, the Historic Iowa State Penitentiary, the Old Montana Prison, and Eastern State Penitentiary, contributing to an emergent “prison public history” that scrutinizes relationships between history, incarceration, and the public imagination.Among those relationships is historic state prison museums’ role in perpetuating the current carceral state—the extraordinary and unprecedented mass incarceration of Americans since the 1970s. How do historic state prison museums, their preservations, managements, and interpretations, contribute to public consciousness regarding contemporary incarceration? Historic state prison museums generally fail to engage or educate the public in critical and meaningful ways, especially about the carceral past and present. This dissertation argues that the majority of historic state prison museums contribute to a punitive public mentality that does not challenge the carceral state, reinforcing societal stereotypes regarding systems and practices of imprisonment, and posturing such patterns as historical with minimal impact on contemporary carceral issues. In so doing, this dissertation offers a scholarly intervention at the intersections of literature on dark tourism, museum studies, and carceral studies. It builds upon recent scholarly and public interest in the causes and consequences of the modern carceral state to situate historic prison museums as contributors to, and perpetuators of, Americans' uncritically romanticized conceptualizations of incarceration.

Development and Field-Testing of the DRAINMOD-FOREST Model for Predicting Water, Soil Carbon and Nitrogen Dynamics, and Plant Growth in Drained Forests

Tian, Shiying North Carolina State University 2011 해외박사(DDOD)

A fully integrated DRAINMOD-FOREST model has been developed to simulate the hydrology, soil carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. DRAINMOD-FOREST was developed by linking the hydrological model, DRAINMOD, and the C and N dynamics model, DRAINMOD-N II, to a newly developed forest growth model. The forest growth model estimates net primary production using a method based on radiation use efficiency and allocates fixed C using tree species-dependent allometric relationships. It simulates the effects of environmental factors (temperature and soil water) and N availability on tree growth (both C fixation and allocation). The forest growth module predicts C input to the forest floor due to foliage litterfall and C input to the soil due to root turnover. The model is applicable to mixed or uneven-aged forest stands as it accounts for resource (water, nutrient, and light) competition among different tree species. It simulates silvicultural practices such as thinning, pruning, harvesting, regeneration, and fertilization, and predicts their impacts on water, C and N cycling. The hydrologic model has been modified by adding a revised Gash rainfall interception algorithm and the Penman-Monteith equation to simulate water losses through wet canopy evaporation and dry canopy transpiration, respectively. The hydrologic model, C and N cycling model, and forest growth model are fully integrated, making DRAINMOD-FOREST a comprehensive, quasi-process-based, and stand level model. The functions and features of DRAINMOD-FOREST were demonstrated using a set of long-term simulations covering two typical rotations of a managed loblolly pine (Pinus taeda L.) plantation in eastern North Carolina, United States. The DRAINMOD-FOREST model was evaluated using a long-term experimental data set from an artificially drained Loblolly pine plantation in eastern North Carolina. The model was calibrated using the data collected during 1988-1997 and validated using the 1998-2008 data. Annual and monthly drainage, as well as daily water table fluctuations were accurately predicted. Annual NPP and daily leaf area index (LAI) dynamics predictions were also comparable to field measurements. Predicted temporal changes in the OC pools on forest floor and in soil profile during the simulation period were reasonable compared to published literatures. Both predicted annual and monthly nitrate export were in good agreement with measured nitrate losses via subsurface drainage. Predicted internal N transformations such as net mineralization, nitrification, and denitrification were also reasonable compared to published literature. The DRAINMOD-FOREST model was further evaluated using 21-year data collected from two intensively managed coastal loblolly pine plantations located in Carteret county of North Carolina, USA. Simulated management practices included controlled drainage and silvicultural practices consist of N fertilizer application, thinning, forest harvesting, site preparation and regeneration. Predicted annual and monthly drainage as well as daily water table depth were in very good agreements with measured values. Predicted C pool dynamics in forest floor and mineral soil reasonably responded to forest managements and climatic conditions. In addition, the model accurately predicted nitrate losses through subsurface drainage on both annual and monthly bases. We verified the validity of predicted hydrological and biogeochemical responses to controlled drainage and silvicultural practices. Special attentions were given to test the validity of the model in predicting hydrological and biogeochemical processes after forest harvesting. The model also reasonably captured alterations of nitrogen transformations processes caused by forest harvesting, such as increased mineralization, nitrification, denitrification rate, and decreased plant uptake. A module was added to the DRAINMOD-NII model to describe key mechanisms and processes regulating dissolved organic nitrogen (DON) losses from terrestrial ecosystems. DON production rates were empirically linked with pool size of litter pool on forest floor and in forest soil, as well as soil microbial compartments. The Langmuir isotherm was used to quantify the assumed instantaneous equilibrium between DON in solid and aqueous phases. DON transport with groundwater flow is simulated using numerical solutions to the advection-dispersion-reaction equation. We calibrated and validated the modified model using 20 years of water flow and DON loading data measured at the outlets of three forested (loblolly pine plantations) watersheds located in eastern North Carolina, USA. Field-testing results indicated that the model is capable of reproducing DON export dynamics on both annual and monthly basis. The good model performance is most likely attributed to accurate predictions of drainage rates and reasonable quantification of biotic and abiotic controls on DON dynamics. Although there are some uncertainties of assumptions and methods adapted by the model, the relatively accurate predictions of DON loads indicates a good performance of the model given current limitations of our understanding of inherent factors and mechanisms controlling DON dynamics. To sum up, this study demonstrated that the DRAINMOD-FOREST model can be utilized to comprehensively predict water, soil C and N dynamics, and plant growth in drained forest ecosystems under intensive management practices.