APAR is a better predictor than LUE of the stem growth differences found between Loblolly pine grown in the United State and Brazil

Anthropogenic climate change and allergen exposure: The role of plant biology

The objective of this study was to evaluate the applicability of Landsat 5 TM images for analysing the textural information on pine forest stands in western Georgia, United States. Analysing spatial correlations between pixels measured by semivariances and cross-semivariances (cross-correlation between two radiometric bands) calculated from transects of Landsat TM images, we explored differences between semivariances associated with images of stands of various ages, origins (natural vs. planted) and species (loblolly pine – Pinus taeda L. – versus longleaf pine – Pinus palustris Mill.). We analysed both ground measurements and the satellite images using the visible, the near infrared, and the middle-infrared bands. We also analysed semivariances and cross-semivariances calculated from the Normalized Difference Vegetation Index and the Ratio Vegetation Index. The results showed that in spite of the relatively low Landsat TM spatial resolution (30m) the semivariograms and cross-semivariograms provided potentially useful information about the above-mentioned classes. The semivariances and cross-semivariances calculated from Landsat TM images of loblolly pine stands depend both on the age and the stand origin. In particular, large differences exist in semivariance and cross-semivariance sills. Significant differences also exist between semivariances calculated from stands of loblolly and longleaf pine.

There is growing evidence suggesting that the United States’ roots are not in a state of “pristine” nature but rather in a “human-modified landscape” over which Native people have since long exerted vast control and use. The longleaf pine is a typical woodland use largely shaped by fires, lightning and by Native Americans. The frequent fires, which were used to reduce fuels and protect themselves from wildfires, enhance wildlife habitats and for hunting, protect themselves from predators and enemy tribes, led to the establishment of the fire dependent and fire tolerant longleaf pine across the southern landscape. In the last 3 centuries however, the range of longleaf ecosystem has been gradually replaced first by agriculture and then by loblolly pine farming. The joint effects of agricultural expansion, intense logging of the longleaf in the late 1800s, expanded fire control since the early 20th century, and subsequent bare-root planting beginning in the 1930s, has permitted loblolly pine to become dominantly established in the south. Longleaf and loblolly pines represent two distinct woodland uses and represent separate human values. This study investigated the change from longleaf pine use to loblolly pine farming in Southern US from perspectives of human values of land and natural resources.

Higher productivities for loblolly pine (Pinus taeda L.) growing at exotic locations (e.g., Hawaii, Brazil) indicate that the full growth potential of this southern pine species has yet to be reached in plantations across the southeastern United States (US). The higher productivity of Hawaii-grown loblolly pine has been attributed to more favorable climate conditions. To date, physical, anatomical, and chemical property data for loblolly pine wood from exotic locations are scarce. Mid-infrared spectroscopy coupled with multivariate analysis was used to screen for chemical differences between wood samples from Hawaii (HI), North Carolina (NC), and Mississippi (MS). The principal component analysis scores plot showed that the MS samples formed a distinct cluster apart from overlapping clusters for the other two sites. Using standard wet chemistry procedures, we found that the mean lignin content for the MS site (30.1%) was significantly lower than that determined for the NC (34.5%) and HI (33.9%) sites; said lower lignin value was offset by significantly higher glucose and mannose contents. Results on the US mainland were seemingly consistent with the greater formation of latewood at sites with longer growing seasons, and the lower lignin content of latewood relative to earlywood shown for pines. Given the low percent latewood for the HI site (37.2%) relative to both mainland sites (MS, 54.8%; NC, 53.1%), yet similar lignin contents between the NC and HI sites, it appears that the relative lignin value for these exotically-grown loblolly pine trees cannot be solely attributed to the proportion of latewood.

Rising export of wood pellets from southern United States would bring more land under loblolly pine (Pinus taeda L.) at the expense of other competitive land uses. We developed an approach to project potential changes in existing land uses by integrating site suitability analysis with historical land use dynamics in a watershed located within Oconee River Basin, Georgia, United States. We developed a GIS-based site suitability model to classify land into three categories (High, Medium, and Low) for loblolly pine. Then, we calculated historical rates of land use changes in the selected watershed. Finally, we integrated the output of suitability analysis with the projected rates of land use changes under the two scenarios of wood pellet demand (High and Low) to determine an increase in area under loblolly pine for 2016, 2021, and 2026 in a spatially explicit manner. Relative to 2011, the combined changes in the shrubland and evergreen forest land cover categories under High Demand scenario were 7.6, 14.6, and 21.1% and under Low Demand scenario were 3.8, 7.5, and 11.1% for the years 2016, 2021, and 2026, respectively. The developed approach could be applied in a relatively short time at modest spatial scales. The outputs of this study can also be used to determine the environmental implications of land use changes for ensuring the overall sustainability of wood-based bioenergy development in the United States and beyond.

Industrial hemp (Cannabis sativa L. <0.3% THC), a non-psychoactive chemotype of cannabis, was reclassified and made legal for growing across the United States under the 2018 Farm Bill. Given that resources, knowledge, and interest for this novel crop are expanding rapidly, we explored the possibility of intercropping industrial hemp for fiber with loblolly pine (Pinus taeda) plantations, one of the most commercially widespread tree species in the southern United States. Following a previous greenhouse study confirming hemp’s ability to grow in pine-influenced soils, we examined the financial feasibility of this potential agroforestry system. We simulated the loblolly pine tree growth information using PTAEDA 4.0, a growth and yield model, and collected the enterprise budget data on hemp productivity, operating and fixed costs, and prices from various sources. Based on the capital budgeting analyses, results suggest that pine-hemp intercropping can yield higher economic returns –at least 25% higher net present value—than the conventional monoculture loblolly pine plantation. The early rotation cash flow and the complimentary benefits can result in a more financially viable loblolly pine plantation under the intercropping scenario. While new research continues to advance further with field trials and other analyses, this study provides valuable insights into the current market conditions and productivity level of industrial hemp cultivation that need to be addressed for hemp intercropping to succeed as an economically viable agroforestry investment.

Global concern over increasing carbon dioxide (CO2) concentrations in the atmosphere leading to possible future climate changes have generated interest in offsetting CO2 emissions by storing carbon in forests. Carbon-sequestering forest activities may be one of the least expensive approaches to mitigate the build up of atmospheric CO2. However, the fact that forest management practices are species-, site-and management-objective-specific increases the complexity of using the forestry sector to mitigate global warming. In order to provide useful and timely information concerning carbon sequestration, this study investigated three forestry-based opportunities for sequestering carbon in the United States: conversion of marginal agricultural land to forests and reforestation of poorly stocked pine plantations in the South, afforestation of the Lower Mississippi Alluvial Valley (LMAV), and reclamation and afforestation of abandoned mined lands (AML). This study conducted economic analyses on three region–species combinations: loblolly pine (Pinus taeda L.) in the southern states, cherrybark oak (Quercus pagoda Raf.) in the LMAV, and northern red oak (Quercus rubra L.) on AML in West Virginia. The objectives of this study were to determine the profitability of managing these three commercial tree species for timber production only and for the combination of timber production and carbon sequestration and then calculate net tonnes of carbon stored during one rotation and net revenues generated from each tonne of carbon sequestered.

Stem respiration and growth in 10-year-old loblolly pine (Pinus taeda L.) plantations were measured monthly during the third year of fertilization and irrigation treatments to determine whether soil resource availability differentially altered growth and respiration in stem tissue. Fertilized trees had significantly greater stem biomass, stem nitrogen concentration ([N]) and growth rate than unfertilized trees. Stem respiration (Rt) was significantly greater in fertilized trees when expressed on a per unit surface area (Rt,a, micromol CO2 m-2 s-1), sapwood volume (Rt,v, micromol CO2 m-3 s-1), or mass (Rt,w, nmol CO2 g-1 s-1) basis; however, there was no difference between treatments when expressed as a function of stem N content (Rt,n, micromol CO2 (mol N)-1 s-1). Irrigation had no significant effect on Rt or annual stem growth. Daily total respiration (Rd, mol CO2 m-2 day-1) and stem diameter growth both had a seasonal bimodal pattern with peaks in early spring and midsummer. Stem [N] declined significantly during the growing season. Stem growth rate and [N] explained 75% of the seasonal variation in temperature-normalized Rt,a. The mature tissue method was used to partition total stem respiration (Rt) into maintenance (Rm) and growth (Rg) components. There was a linear correlation between winter Rt,v, a measure of basal Rm, and sapwood N content; however, Rt,v per unit N was greater in January before diameter growth started than in the following December after growth ceased, indicating that Rt,v declined as stem diameter increased. Consequently, estimates of annual maintenance respiration (RM) based on January data were 44% higher than estimates based on December data. Growth respiration was correlated with stem growth rate (r2 = 0.55). The growth respiration coefficient (rg)-the slope of the relationship between Rg and stem growth rate-was 0.24. Respiration accounted for 37% of annual stem carbon budget. Stem carbon-use efficiency (CUE)-the ratio of stem growth to stem growth plus respiration-averaged 0.63 and was unaffected by fertilization.

There is growing interest in using switchgrass (Panicum virgatum L.) as a biofuel intercrop in forestry systems. However, there are limited data on the longevity of intercropped bioenergy crops, particularly with respect to light availability as the overstory tree canopy matures. Therefore, we conducted a greenhouse study to determine the effects of shading on switchgrass growth. Four treatments, each with different photosynthetically active radiation (PAR) levels, were investigated inside the greenhouse: control (no shade cloth, 49 % of full sunlight), low (under 36 % shade cloth), medium (under 52 % shade cloth), and heavy shade (under 78 % shade cloth). We determined the effect of shading from March to October 2011 on individually potted, multi-tillered switchgrass transplants cut to a stubble height of 10 cm. In the greenhouse, there was a reduction in tiller number, tiller height, gas exchange rates (photosynthesis and stomatal conductance), leaf area, above- and belowground biomass and light-use efficiency with increasing shade. Total (above- and belowground) biomass in the control measured 374 ± 22 compared to 9 ± 2 g pot−1 under heavy shade (11 % of full sunlight). Corresponding light-use efficiencies were 3.7 ± 0.2 and 1.4 ± 0.2 g MJ−1, respectively. We also compared PAR levels and associated aboveground switchgrass biomass from inside the greenhouse to PAR levels in the inter-row regions of a range of loblolly pine (Pinus taeda L.) stands from across the southeastern United States (U.S.) to estimate when light may limit the growth of intercropped species under field conditions. Results from the light environment of loblolly pine plantations in the field suggest that switchgrass biomass will be significantly reduced at a loblolly pine leaf area index between 1.95 and 2.25, which occurs on average between ages 6 and 8 years across the U.S. Southeast in intensively managed pine plantations. These leaf area indices correspond to a 60–65 % reduction in PAR from open sky.

Root feeding bark beetles in the genus Hylastes Hylastes breeding in loblolly pine across 3 crown (Coleoptera: Curculionidae: Scolytinae) commoncondition classes (healthy, dying, dead). Addition ly carry ophiostomatoid fungi (Ophistomatales: ally, the relationship between ophiostomatoid Ophistomataceae)and collectively contribute to species, their Hylastes species vectors, and tree root disorders of Pinus species around the world condition were investigated. (Jacobs & Wingfield 2001). One of the most damLoblolly pine stands across central Alabama aging root disorders is black-stain root disease have experienced high mortality rates, character of conifers in the Western United States, caused ized by scattered stand mortality with a distinct by the fungal species Leptographium wageneri lack of above-ground pests (Brown & McDowell Kendrick and its primary beetle vector H. nig1968). During an investigation of one stand in rinus (Mannerheim) (Witcosky et al. 1986). ReMay 2008 in central Alabama, dying trees were cently, Hylastes salebrosus Eichhoff and H. tenuis found to be infested with root-inhabiting beetles Eichhoff have been associated with loblolly pine and their associated ophiostomatoid fungi. Six (Pinus taeda L.) decline (Eckhardt et al. 2007), trees were selected based on crown condition, in which is considered an emerging forest health iseluding 2 with green, healthy crowns (healthy), sue in the southeastern United States (Eckhardt 2 with severely chlorotic and thinning crowns et al. 2010). (dying), and 2 with red crowns (dead). Two pri Loblolly pine decline (LPD) is a tree disease mary lateral roots were randomly selected and complex that is characterized by symptoms that excavated to approximately 3 meters from the include thinning tree crowns, growth reductions root collar. Roots were removed from trees and (Eckhardt et al. 2007) and premature mortality in carefully dissected. All insects, including imma localized areas (Brown and McDowell 1968). Eviture stages, were collected from roots and adult dence suggests the complex is the result of interbeetles were identified to species. Root tissue was acting abiotic (Eckhardt & Menard 2008) and biobtained from each brood gallery for the isolation otic (Eckhardt et al. 2007) stress factors. Hylastes of ophiostomatoid fungal species using methods species vector a variety of root-infecting ophiostodescribed in Eckhardt et al. (2007). Following matoid fungi (Klebzig et al. 1991, 1995; Eckhardt surface sterilization, tissue was placed on CSMA et al. 2007; Zanzot et al. 2010) which are patho(malt extract agar containing 800 mg/L of cyclo genic to loblolly pine (Matusick & Eckhardt 2010; heximide and 200 mg/1 of streptomycin sulfate) Matusick et al. 2011). Hylastes beetles and their selective nutrient agar (Jacobs & Wingfield 2001). associated fungi are thought to collectively contribEach adult insect was also rolled on CSMA to re ute to LPD by causing root damage through fungal cover ophiostomatoid fungi from insect bodies infection and insect feeding (Eckhardt et al. 2007). (Zanzot et al. 2010). Isolated ophiostomatoid fun Root and lower stem feeding beetle species (Colegal species were identified using morphological optera: Curculionidae) includingH. salebrosus and characters and established keys. Unknown iso H. tenuis are found in increased numbers within lates were sequenced and confirmed as new spe LPD-affected stands, compared to healthy stands cies by M. Wingfield (Forestry and Agricultural (Eckhardt et al. 2007, Menard 2007). A recent Biotechnology Institute, Pretoria, South Africa), study has found Hylastes to be the most common A total of 157 adult beetles (Coleoptera: Cur bark beetle genus observed in loblolly pine stands culionidae) were collected from roots, most from in central Alabama (Thompson 2011), illustrating dying trees (Table 1). A majority of the beetles col their dominance in this ecosystem. Despite their lected were Hylastes species, including a total of dominance and potential for damage in loblolly 113 H. salebrosus (all from dying trees) and 34 pine, the breeding behavior of Hylastes species in H. tenuis (31 from dying and 3 from dead trees), the southeastern United States is not well underIn addition, H. salebrosus larvae and pupae were stood. In the current study, observational methcollected from dying trees. Other adult insect spe ods were used to investigate the potential for cies collected include the black turpentine beetle

The main objective of this study was to assess the economics of alley cropping of loblolly pine (Pinus taeda L.) and switchgrass (Panicum virgatum) in the southern United States. Assuming a price range of switchgrass between $15 and $50 Mg−1 and yield of 12 Mg ha−1 year−1, we investigated the effect of switchgrass production on the optimal forest management for loblolly pine stands under different stumpage prices. We considered the following potential scenarios: no competition between species for resources; reduced loblolly pine productivity due to competition with switchgrass; and reduced productivity of both species due to competition for nutrients, water and light. Findings also suggested that the optimal system would depend on the competitive interactions between switchgrass and loblolly pine crops, and the expected prices for each crop. Loblolly pine monoculture would be the most profitable option for landowners compared to intercropping systems with switchgrass below $30 Mg−1. However, when switchgrass prices are ≥$30 Mg−1, landowners would be financially better off adopting intercropping if competitive interaction between crops were minimal. In order to realize higher economic returns for intercropping system, forest landowners must make some efforts in order to diminish the decline of productivity.

Loblolly pine (Pinus taeda L.), the most widely planted tree species in the United States, is an important source of wood and wood fibers for a multitude of consumer products. Wood fibers are primarily composed of secondary cell walls, and cellulose, hemicelluloses and lignin are major components of wood. Fiber morphology and cell wall composition are important determinants of wood properties. We used comparative genomics to identify putative genes for cellulose and hemicellulose synthesis in loblolly pine that are homologous to genes implicated in cell wall synthesis in angiosperms. Sequences encoding putative secondary cell wall cellulose synthase genes, cellulose synthase-like genes, a membrane-bound endoglucanase gene, a sucrose synthase gene, a UDP-glucose pyrophosphorylase gene and GDP-mannose pyrophosphorylase genes were identified in expressed sequence tag (EST) collections from loblolly pine. Full-length coding sequences were obtained from cDNA clones isolated from a library constructed from developing xylem. Phylogenetic relationships between the genes from loblolly pine and angiosperm taxa were examined and transcriptional profiling in vascular tissues was conducted by real-time quantitative, reverse transcriptase-polymerase chain reaction. The putative cell wall synthesis genes were expressed at high levels in vascular tissues and a subset was differentially regulated in xylem and phloem tissues. Inferred phylogenetic relationships and expression patterns for the genes from loblolly pine were consistent with roles in synthesis of complex carbohydrates of the cell wall. These studies suggest functional conservation of homologous wood formation genes in gymnosperm and angiosperm taxa.

Aboveground biomass and nitrogen in four short-rotation woody crop species growing with different water and nutrient availabilities

Loblolly pine (Pinus taeda L.) is one of the most important commercial timber species in the world. While the species is native to the southeastern United States of America (USA), it has been widely planted in southern Brazil, where it is the most commonly planted exotic species. Interest exists in utilizing nondestructive testing methods for wood property assessment to aid in improving the wood quality of Brazilian grown loblolly pine. We used near-infrared hyperspectral imaging (NIR-HSI) on increment cores to provide data representative of the radial variation of families sampled from a 10-year-old progeny test located in Rio Negrinho municipality, Santa Catarina, Brazil. Hyperspectral images were averaged to provide an individual NIR spectrum per tree for cluster analysis (hierarchical complete linkage with square Euclidean distance) to identify trees with similar wood properties. Four clusters (0, 1, 2, 3) were identified, and based on SilviScan data for air-dry density, microfibril angle (MFA), and stiffness, clusters differed in average wood properties. Average ring data demonstrated that trees in Cluster 0 had the highest average ring densities, and those in Cluster 3 the lowest. Cluster 3 trees also had the lowest ring MFAs. NIR-HSI provides a rapid approach for collecting wood property data and, when coupled with cluster analysis, potentially, allows screening for desirable wood properties amongst families in tree improvement programs.

The National Science and Technology Council developed a 5-year plan in 2013 to ensure that science, technology, engineering, and mathematics (STEM) experienced sustained growth within the United States (US). Nursing is comprised of multiple sciences that include chemistry, physics, biology, microbiology, anatomy and physiology, pharmacology, and the social and behavioral sciences of sociology, developmental lifespan psychology, and psychology. Science, technology, engineering, and math constitute the traditional STEM acronym. Nursing programs graduate nurses with both the rigorous academic coursework and diverse clinical skills necessary to provide patient care. These skills employed by nurses in the clinical setting can serve as the basis for the inclusion of the nursing profession as a STEM-designated profession by the federal government and educational institutions within the US. Currently, the US government does not acknowledge the profession of nursing as a STEM-designated profession. Acknowledgment of nursing as a STEM profession could potentially make more funding available for nursing education within the US and address nursing shortages both in clinical and academic settings. As well as position professional nurses for careers not only within the health sector but that of business and industry because of nurses' STEM knowledge. Hence, enhancing the growth of STEM within the US and creating global market economic competitiveness with new innovation development. In the practice of nursing, nurses apply the sciences, math, and innovative technology in the assessments, diagnoses, and planning of patients' care. Nurses implement scientifically-based interventions to treat illness and sustain human life and to ultimately evaluate the outcomes of the care provided to patients. Methodologies of evaluation of outcomes of patient care status post nursing interventions (ie, administration of intravenous antibiotics to treat pneumonia) are based upon rationales that have been derived from evidenced-based practice and nursing research; both originating from applied STEM knowledge. The formal designation by the US federal government, for nursing to be recognized as a STEM profession, can increase funding to the nursing profession and enhance the diversity of employment opportunities for nurses in industry and business. Thereby potentially decreasing nursing shortages and bringing national and worldwide recognition to nursing in both academia, industry, business, and clinical settings, as a profession contributing to the science of improvement of the health of all people through STEM knowledge.