Visando caracterizar a dinâmica de crescimento do Pinus taeda no sul do Brasil, este estudo teve os seguintes objetivos: i) determinar os principais fatores edafo-climáticos e do povoamento associados à ampla variação de produtividade da espécie; e ii) caracterizar padrões de crescimento e uniformidade, do plantio até 9 anos em diferentes regiões edafoclimáticas. Para isso, foram selecionadas 24 parcelas sem desbaste (700m²), com aproximadamente 1450 árvores ha-1, entre 8 a 10 anos de idade, do projeto PPPIB (Produtividade Potencial do Pinus no Brasil), as quais estão localizadas em Jaguariaíva-PR, Ponta Grossa-PR, Rio Negrinho-SC e Três Barras-SC. O clima destas regiões é temperado úmido, com precipitação média anual de 1477mm, com temperaturas máxima, média e mínima de 24,3ºC, 17,9ºC e 12,7ºC. Todas as variáveis biométricas foram determinadas através do banco de dados de inventário (2006-2009), dados de cubagem, análise de tronco (discos), de anéis de crescimento (baguetas) e massa específica aparente (densitometria de raios-X). Coletaram-se solos (0-20cm) nas parcelas de inventário, e obtiveram-se os dados climáticos de estações meteorológicas locais. Através das análises de disco determinaram-se os índices de sítio (idade base 10 anos), e através da bagueta e densitometria de raios-X, estimaramse o padrão de crescimento de todas as parcelas em volume (m³ha-1) e matéria seca (Mgha-1) e seus Incrementos Médios Anuais e Correntes Anuais até o 9º ano. A uniformidade foi avaliada através do coeficiente de variação de volume das árvores dentro das parcelas (CVV) e da percentagem de biomassa em 50% das árvores mais finas (PB50), dos 2 aos 9 anos. As regiões apresentaram grande variação das propriedades físico-químicas do solo, como profundidade (30-140cm), teor de matéria orgânica (23 a 65g dm-3), teor de argila (20 a 85%), quantidade de N (500 a 5300kg ha- 1), e quantidade de P (9 a 84kg ha-1). Aos 9 anos de idade todas parcelas não haviam culminado seu crescimento, e o incremento médio anual com casca (IMAc9), o estoque de biomassa do lenho e índice de sítio de idade base 10 (IS10) variaram de 15 a 35m³ ha-1 ano-1, de 55 a 130Mg ha-1, e 12 a 19m, respectivamente, com maiores valores em Três Barras. Esta caracterização não era possível de ser detectada antes do 6º ano, mostrando que as decisões silviculturais ou genéticas precoces em Pinus precisam ser cuidadosamente consideradas. A produtividade (IMA) foi positivamente relacionada com o IS10, e ambos estiveram relacionados com os maiores teores de matéria orgânica do solo, quantidade de nitrogênio disponível e menores médias de temperatura mínima e déficit hídrico. As florestas mais produtivas se mostraram também mais uniformes (menores CVV e maiores PB50), mas confundidas com material genético superior. Assim, o estudo corrobora o papel dos nutrientes, solos de boa drenagem, e condição climática amena e com baixo déficit hídrico na explicação da elevada produtividade do P.taeda no sul do Brasil, comparativamente a sua região de origem. Baseado nestes resultados, estudos de fertilização, material genético e uso rotineiro de análise do tronco, associado à densitometria de raios-X, podem ser recomendados para o P. taeda. / The study was designed to characterize the growth dynamics of Pinus taeda in south of Brazil and had the following objectives: i) determine the main edaphic, climatic and stand factors associated with the range in productivity of the species; and ii) characterize the growth patterns and uniformity, from planting until 9 years-old, across different edaphic and climatic regions. A total of 24 unthinned plots were selected (700m2), with stocking of 1450 trees ha-1, between 8 and 10 years old, from the PPPIB project (Pine Potential Productivity in Brazil), and are located in Jaguariaíva-PR, Ponta Grossa-PR, Rio Negrinho-SC and Três Barras-SC. The climate of these regions is temperate humid (Cfb), with mean annual precipitation of 1477mm, and maximum, mean and minimum temperatures of 24.3ºC, 17.9ºC e 12.7ºC. The biometric variables were assessed using inventory datasets (2006-2009), destructive sampling, bole analysis (disks), growth rings (stem coring), and specific gravity (X-ray densitometry). Soil samples (0-20cm) were collected on inventory plots, and climatic data were obtained from local weather stations. Site index (base age 10 years) were determined using bole disks, and growth patterns of all plots (m3ha-1), dry mass (Mgha-1), mean and current annual increments until 9th year were determined using stem coring and X-ray densitometry. Stand uniformity was evaluated using tree volume coefficient of variation within plots (CVV) and percentage of biomass for the 50% thinnest trees (PB50), from ages 2 to 9. Regions showed a wide range of soil physical and chemical properties, such as soil depth (30-140cm), organic matter levels (23 a 65g dm-3), clay content (20 a 85%), amount of N (500 a 5300kg ha-1), and amount of P (9 a 84kg ha-1). At 9 years old all the plots did not reached their maximum growth; and mean annual increment with bark (IMAc9), standing stem biomass and site index at base age 10 (IS10) ranged from 15 to 35m³ ha-1 year-1, 55 to 130Mg ha-1, and 12 a 19m, respectively, with higher values on Tres Barras region. This characterization was not possible to be detected before the 6th year, showing that early silvicultural and genetic decisions in Pinus need to be carefully considered. The productivity (IMAc9) was positively related with IS10, and both were related with higher levels of soil organic matter and available nitrogen, and with lower averages of minimum temperatures and water deficit. The most productive forests showed to be more uniform also (lower CVV and higher PB50), but confounded with superior genetic material. Therefore, the study corroborates with the role of nutrients, well drained soils, mild climatic conditions and low water deficit to explain the high yileds of P.taeda in Brazil, comparatively to its original region. Based on these results, studies of fertilization, genetic material and more frequent use of bole analysis, associated with X-ray densitometry, might be recommended for P. taeda.

Visando caracterizar a dinâmica de crescimento do Pinus taeda no sul do Brasil, este estudo teve os seguintes objetivos: i) determinar os principais fatores edafo-climáticos e do povoamento associados à ampla variação de produtividade da espécie; e ii) caracterizar padrões de crescimento e uniformidade, do plantio até 9 anos em diferentes regiões edafoclimáticas. Para isso, foram selecionadas 24 parcelas sem desbaste (700m²), com aproximadamente 1450 árvores ha-1, entre 8 a 10 anos de idade, do projeto PPPIB (Produtividade Potencial do Pinus no Brasil), as quais estão localizadas em Jaguariaíva-PR, Ponta Grossa-PR, Rio Negrinho-SC e Três Barras-SC. O clima destas regiões é temperado úmido, com precipitação média anual de 1477mm, com temperaturas máxima, média e mínima de 24,3ºC, 17,9ºC e 12,7ºC. Todas as variáveis biométricas foram determinadas através do banco de dados de inventário (2006-2009), dados de cubagem, análise de tronco (discos), de anéis de crescimento (baguetas) e massa específica aparente (densitometria de raios-X). Coletaram-se solos (0-20cm) nas parcelas de inventário, e obtiveram-se os dados climáticos de estações meteorológicas locais. Através das análises de disco determinaram-se os índices de sítio (idade base 10 anos), e através da bagueta e densitometria de raios-X, estimaramse o padrão de crescimento de todas as parcelas em volume (m³ha-1) e matéria seca (Mgha-1) e seus Incrementos Médios Anuais e Correntes Anuais até o 9º ano. A uniformidade foi avaliada através do coeficiente de variação de volume das árvores dentro das parcelas (CVV) e da percentagem de biomassa em 50% das árvores mais finas (PB50), dos 2 aos 9 anos. As regiões apresentaram grande variação das propriedades físico-químicas do solo, como profundidade (30-140cm), teor de matéria orgânica (23 a 65g dm-3), teor de argila (20 a 85%), quantidade de N (500 a 5300kg ha- 1), e quantidade de P (9 a 84kg ha-1). Aos 9 anos de idade todas parcelas não haviam culminado seu crescimento, e o incremento médio anual com casca (IMAc9), o estoque de biomassa do lenho e índice de sítio de idade base 10 (IS10) variaram de 15 a 35m³ ha-1 ano-1, de 55 a 130Mg ha-1, e 12 a 19m, respectivamente, com maiores valores em Três Barras. Esta caracterização não era possível de ser detectada antes do 6º ano, mostrando que as decisões silviculturais ou genéticas precoces em Pinus precisam ser cuidadosamente consideradas. A produtividade (IMA) foi positivamente relacionada com o IS10, e ambos estiveram relacionados com os maiores teores de matéria orgânica do solo, quantidade de nitrogênio disponível e menores médias de temperatura mínima e déficit hídrico. As florestas mais produtivas se mostraram também mais uniformes (menores CVV e maiores PB50), mas confundidas com material genético superior. Assim, o estudo corrobora o papel dos nutrientes, solos de boa drenagem, e condição climática amena e com baixo déficit hídrico na explicação da elevada produtividade do P.taeda no sul do Brasil, comparativamente a sua região de origem. Baseado nestes resultados, estudos de fertilização, material genético e uso rotineiro de análise do tronco, associado à densitometria de raios-X, podem ser recomendados para o P. taeda. / The study was designed to characterize the growth dynamics of Pinus taeda in south of Brazil and had the following objectives: i) determine the main edaphic, climatic and stand factors associated with the range in productivity of the species; and ii) characterize the growth patterns and uniformity, from planting until 9 years-old, across different edaphic and climatic regions. A total of 24 unthinned plots were selected (700m2), with stocking of 1450 trees ha-1, between 8 and 10 years old, from the PPPIB project (Pine Potential Productivity in Brazil), and are located in Jaguariaíva-PR, Ponta Grossa-PR, Rio Negrinho-SC and Três Barras-SC. The climate of these regions is temperate humid (Cfb), with mean annual precipitation of 1477mm, and maximum, mean and minimum temperatures of 24.3ºC, 17.9ºC e 12.7ºC. The biometric variables were assessed using inventory datasets (2006-2009), destructive sampling, bole analysis (disks), growth rings (stem coring), and specific gravity (X-ray densitometry). Soil samples (0-20cm) were collected on inventory plots, and climatic data were obtained from local weather stations. Site index (base age 10 years) were determined using bole disks, and growth patterns of all plots (m3ha-1), dry mass (Mgha-1), mean and current annual increments until 9th year were determined using stem coring and X-ray densitometry. Stand uniformity was evaluated using tree volume coefficient of variation within plots (CVV) and percentage of biomass for the 50% thinnest trees (PB50), from ages 2 to 9. Regions showed a wide range of soil physical and chemical properties, such as soil depth (30-140cm), organic matter levels (23 a 65g dm-3), clay content (20 a 85%), amount of N (500 a 5300kg ha-1), and amount of P (9 a 84kg ha-1). At 9 years old all the plots did not reached their maximum growth; and mean annual increment with bark (IMAc9), standing stem biomass and site index at base age 10 (IS10) ranged from 15 to 35m³ ha-1 year-1, 55 to 130Mg ha-1, and 12 a 19m, respectively, with higher values on Tres Barras region. This characterization was not possible to be detected before the 6th year, showing that early silvicultural and genetic decisions in Pinus need to be carefully considered. The productivity (IMAc9) was positively related with IS10, and both were related with higher levels of soil organic matter and available nitrogen, and with lower averages of minimum temperatures and water deficit. The most productive forests showed to be more uniform also (lower CVV and higher PB50), but confounded with superior genetic material. Therefore, the study corroborates with the role of nutrients, well drained soils, mild climatic conditions and low water deficit to explain the high yileds of P.taeda in Brazil, comparatively to its original region. Based on these results, studies of fertilization, genetic material and more frequent use of bole analysis, associated with X-ray densitometry, might be recommended for P. taeda.

The specific objectives of this project were: 1) Determine financial viability of enrolling forest landowners in Chicago Climate Exchange (CCX) forestry carbon offset protocols; 2) Determine financial trade-offs associated with managing loblolly pine (Pinus taeda L.) and Cherrybark oak (Quercus pagoda Raf.) stands for increased carbon sequestration and timber; 3) Examine financial feasibility of increasing carbon accumulation in wood products carbon by extending rotation length of loblolly pine stands; and 4) Explore potential impacts of carbon policies and programs on future carbon accumulation in Mississippi’s forest sector.

Appropriate management of mid-rotation pine plantations can improve habitat for early successional and pine-grassland adapted avian species. I tested effects of Imazapyr selective herbicide and prescribed fire on plant and avian communities in thinned, mid-rotation pine stands contracted under the Conservation Reserve Program. Within 12 replicate sites, 2 8.1-ha plots were assigned either herbicide and prescribed fire treatment or control. I described components of vegetation structure and composition in 2006. I tested effects of herbicide and prescribed fire treatment on avian relative abundance, species richness, total avian conservation value, and density of select species during 2003 - 2006. Hardwood midstory decreased and abundances of grasses and forbs increased following treatment. A shift occurred in the bird community from closed-canopy forest species to early successional and pine-grassland species. Treatment stands benefited many avian species exhibiting negative population trends.

Pine tree substrate (PTS) produced from freshly harvested loblolly pine (Pinus taeda L.) trees has potential for replacing or reducing the use of aged pine bark (PB) and peat moss as container substrates for horticulture crop production. The objective of this work was to determine the factors influencing nutrient availability in PTS compared to PB or peat substrates. Chapter two reports data on the response of japanese holly and azalea to fertilizer rate when grown in PTS and PB. This study demonstrated that an additional 2.4 kg·m-3 of Osmocote Plus (15N-3.9P-10K) controlled release fertilizer is required for both species when grown in PTS compared to PB. Data are reported in chapter three on the effects of fertilizer rate, substrate particle size, and peat amendment on growth and floral quality, and on post-production time-to-wilting of poinsettias. Data from this work show that PTS requires an additional 100 mg·L-1 N to grow poinsettias comparable to plants grown in peat unless the particle size of PTS was decreased or 25% peat was added, in which case no additional fertilizer was needed. Results also indicated that PTS shrinkage was similar to that of peat, and that post-production time-to-wilting in PTS plants was similar as plants grown in peat. Data in chapter four compares nitrogen (N) immobilization rates, substrate carbon dioxide (CO₂) efflux levels, and nutrient leaching in peat, PB, and PTS over time. Data from these studies indicated that more N immobilization occurs in PTS than in PB or peat and that the substrate CO₂ efflux levels (estimate of microbial activity) corresponds to N immobilization in all substrates. Nutrient availability, changes in physical and chemical properties, substrate shrinkage, and microbial activity in PTS compared to PB during long-term nursery production are reported in chapter five. Results showed that substrate nutrient levels remain lower in PTS and that pH levels of PTS decrease considerably over two growing seasons compared to PB. Results also indicate that PTS does decompose over time in containers, but substrate shrinkage of PTS is similar to that of PL and PB during crop production. / Ph. D.

The Southeastern Lower Coastal Plain wet pine flats include thousands of acres of jurisdictional wetlands that are economically, socially, and environmentally important. These highly productive forests have been intensively managed as pine plantations for the past few decades. More recently, harvesting and site preparation practices have become a concern among natural resource managers because intensive forestry practices may alter soil physical properties and site hydrology. These alterations could decrease seedling survival, growth, and future site productivity. However, the effects of soil disturbance on long-term site productivity and the effects of amelioration techniques on site hydrology are uncertain. The overall objectives of this study were (1) to characterize disturbed forest soil morphology and physical properties, (2) to assess their impact on the processes that control site hydrology and site productivity, (3) to determine effects of harvesting and site preparation on site hydrology, specifically on the overall hydrological balance and on spatial and temporal patterns of surface water storage. The study site is located in an intensively managed loblolly pine (Pinus taeda L.) plantation in the lower coastal plain of South Carolina. This study was established in winter 1991, and dry- and wet-weather harvesting treatments were installed in summer 1993 and winter 1994, respectively. Bedding and mole channel/bedding treatments were installed in both dry- and wet-harvested plots in fall 1995. Soil profiles were described for a recently disturbed, deeply-rutted area, and 2-year-old deeply-rutted and churned areas, bedded and undisturbed areas. Intact soil core samples and composite loose soil samples were collected from each morphological section for soil physical characterizations. Automated weather station and wells were used to collect continuous climatic and surface water level data since 1996. Surface water levels were monitored monthly on a 20 x 20 m grid of 1-m wells since 1992. Total groundwater heads were determined from differential piezometer measurements at high and low elevation places in each treatment plot. Soil profile descriptions and soil physical property measurements indicated that significant amounts of organic debris were incorporated into the surface horizons, and subsurface soil horizons showed significant soil structural changes and increased redoximorphic features caused by soil disturbance. The disturbed soil layers in recently created traffic ruts consisted of exposed and severely disturbed subsurface soils, but this layer was naturally ameliorated 2 years after the disturbance. Bedding site preparation had little amelioration effects on the physical properties of surface soil horizons because the surface horizons already had some incorporation of organic debris. Overall, the main consequence of bedding in a disturbed wet site was to increase the aerated soil volume. The bedding appeared to have little effect on disturbed subsurface horizons. Groundwater head in the study site was constantly higher than -25 cm during the study period, which caused groundwater inflow when the surface water level was low. Frequent fluctuation of the surface water level and constant water supply from the groundwater probably explain the high productivity of the study site. Results of the annual water balance showed that surface soil water storage changes were very small, and annual precipitation and potential evapotranspiration were approximately equal. Silvicultural practices and minor topography on the study site had significant effects on the water balance because they influenced surface water level. Surface water hydraulic gradient evaluation and multivariate cluster analysis indicated that micro-site hydrology and water flow patterns were significantly altered by wet-weather harvesting and bedding site preparation, but overall site hydrology was not altered. Evaluation of predicted surface water level indicated that micro-topography and precipitation patterns had significant influences on surface water levels during the site establishment period. These results revealed that the hydrologic components of wetland delineation are complex in the wet pine flatwoods. / Ph. D.

Exogenously supplied organoselenium compounds, capable of propagating a selenium redox cycle, were shown to supplement natural cellular defenses against oxidants generated during biological activity. Phenylaminoalkyl selenides were developed in our laboratory as novel substrate analogs for the enzyme dopamine beta-monooxygenase. Recently, phenylaminoalkyl selenides were found to protect plasmid DNA and Molecular beacons from oxoperoxynitrate – mediated damage by scavenging this oxidant and forming the corresponding selenoxides as the sole selenium – containing products. Rate constants were determined for the reactions of the phenylaminoalkyl selenoxides with GSH at physiological pH and 25 degrees C. The kinetic data obtained in current and previous research was subsequently used in a MatLab simulation, which showed the feasibility of selenium redox cycling by GSH in the presence of a cellular oxidant, oxoperoxynitrate. Loblolly pine (LP, Pinus taeda) is the primary commercial species in southern forests covering 11.7 million hectares. Somatic embryogenesis (SE) is an effective technique to implement production of high value genotypes of LP. SE is a multi-step process, which includes initiation of somatic embryo (SME) growth from tree tissue, maintenance and multiplication of early stage SMEs and the maturation / germination phase. In this work, we isolated a substance from stage 2 or 3 LP female gametophyte (FG) tissue that stimulates early stage SME growth, and characterized this substance as citric acid on the basis of 1H NMR and mass spectrometry. We then demonstrated that topical application of citric acid to SMEs stimulates embryo colony growth at p = 0.05 for 3 of the 5 genotypes tested. Phenylketonuria (PKU) is an autosomal recessive disorder caused by an impaired conversion of L-phenylalanine (L-Phe) to L-tyrosine (L-Tyr). A novel assay based on enzymatic - colorimetric methodology (ECA) was developed in order to detect elevated concentrations of L-Phe in undeproteinized plasma of PKU patients via continuous spectrophotometric detection. We report here that L-Phe concentrations in undeproteinized plasma measured using our ECA were comparable to those determined on an amino acid analyzer based on Pearson correlation coefficients and a Bland and Altman comparison.

Cellular internalization of large therapeutic agents such as proteins or nucleic acids is a challenging task because of the presence of the plasma membrane. One strategy to facilitate intracellular drug uptake is to induce transient pores in the cell membrane through physical delivery strategies. Physical approaches are attractive as they offer more generic applicability compared with viral or biochemical counterparts. Pulsed laser light can induce the endothermic carbon-steam reaction in carbon-nanoparticle suspensions to produce explosive photoacoustic effects in the surrounding medium. In this study, for the first time, these photoacoustic forces were used to transiently permeabilize the cell membrane to deliver macromolecules into cells. Intracellular delivery using this method was demonstrated in multiple cell types for uptake of small molecules, proteins and DNA. At optimized conditions, uptake was seen in up to 50% of cells with nearly 100% viability and in 90% of cells with ≥90% viability, which compared favorably with other physical methods of drug delivery. Cellular bioeffects were shown to be a consequence of laser-carbon interaction and correlated with properties of the carbon and laser, such as carbon concentration and size, laser pulse duration, wavelength, intensity and exposure time. Similar results were observed using two different lasers, a femtosecond Ti: Sapphire laser and a nanosecond Nd: YAG laser. Uptake was also shown in murine skeletal muscles in vivo with up to 40% efficiency compared to non-irradiated controls. This synergistic use of nanotechnology with advanced laser technology could provide an alternative to viral and chemical-based drug and gene delivery.

Pine tree substrate (PTS) is a relatively new substrate for container crop production. There are no detailed studies that elucidate how storage time impacts PTS chemical, physical, and biological aspects. The objective of this research was to determine how PTS storage time influenced PTS chemical and physical properties, nitrification, and plant growth. Pine tree substrate was manufactured by hammer-milling chips of loblolly pine trees (Pinus taeda L.) through two screen sizes, 4.76 mm (PTS) and 15.9 mm amended with peat (PTSP). PTS and PTSP were amended with lime at five rates. A peat-perlite mix (PL) served as a control treatment. Prepared substrates were placed in storage bags and stored in an open shed in Blacksburg, Virginia. Subsamples were taken at 1, 42, 84, 168, 270, and 365 days. At each subsampling day, twelve 1-L containers were filled with each substrate. Six containers were left fallow and six were planted with marigold (Tagetes erecta L. "Inca Gold") seedlings. Substrate was also collected from select treatments for Most Probable Number assays to estimate density of nitrifying microorganisms, and for chemical and physical property analyses. Pour-through extracts were collected from fallow containers at 0, 2, and 4 weeks, and from marigold containers at harvest for determination of pH, electrical conductivity, ammonium-N and nitrate-N. At harvest, marigold height, width, and dry weight were measured. At least 1 kg·m-3 lime for PTS, and 2 to 4 kg·m-3 lime for PTSP were needed to maintain pH values ≥ 5.5 for 365 days. Bound acidity of unlimed PTS increased but cation exchange capacity for unlimed PTS and PTSP decreased over 365 days. Carbon to nitrogen ratio and bulk density values were unchanged over time in all treatments. There were minor changes in particle size distribution for limed PTS and unlimed and limed PTSP. Marigold growth in PTS and PTSP was ≥ PL in all limed treatments, except at day 1. Nitrite-oxidizing microorganisms were present and nitrification occurred in PTS and PTSP at all subsampling days. Pine tree substrate is relatively stable in storage, but pH decreases, and lime addition may be necessary to offset this decrease. / Ph. D.