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This article takes a close look at the history of an American tree now known as sassafras but known to the Timucua of early modern Florida aspauame. Sassafras root was a major anti-febrile medicament in the early modern world. The history of that medicament has thus far primarily been written in terms of the Spanish empire, which commodified it in post-contact Eurasia. Yet Native Americans, in particular the Timucua, as well as the French, the British, and the Russians, all played major roles in the history of sassafras. That history involves several objects derived from the tree sometimes called sassafras, knowledge about those objects, and Eurasian ideas about the Americas. This article focuses on the issues of entangled empires, and commodity and knowledge exchanges, to show that early modern commodities were not unitary objects, but rather shifting entanglements of objects, words, and ideas.

BackgroundSassafrashas been considered to belong to trib. Laureae of Lauraceae and has been assumed to have unisexual flowers. However, recent molecular phylogenetic studies have consistently suggested thatSassafrasdoes not belong to the trib. Laureae but to Cinnamomeae and that it is nested withinCinnamomum. A recent morphological study revealed that one of the Asian species,S. randaiense, possesses bisexual flowers that are plesiomorphic in the family Lauraceae. As reports on the flower structure of the second Asian species,S. tzumu, have been contradictory, we wanted to ascertain if it has bisexual flowers or not. If the flowers were bisexual, could earlier reports that they were unisexual have been based on dichogamous flowering?ResultsIn this study, we investigated two populations ofS. tzumu. We found that this species has determinate botryoid racemes, and possesses bisexual flowers. Among the three extant species,S. tzumuis more similar to its sister speciesS. randaiensebut markedly different from the AmericanS. albidum: the two Asian species possess bisexual flowers while the American species has unisexual flowers. The bisexual flower ofS. tzumuis protogynous, and shows two phenological phases typical of Lauraceae: 1) in a flower, the pistil functions first, the stigma is fresh and white, stamens of the outer two whorls are spreading, anthers do not open, and the staminodes secrete nectar at this stage; 2) in the second phase, the stigma becomes brown, staminodes are withered, stamens of the third whorl stand up and surround the pistil, glands of the third whorl of stamens secrete nectar, and the anthers open and release pollen.ConclusionsThe similarity of racemose inflorescences betweenSassafrasand some members of Laureae were caused by parallel evolution; the racemose inflorescence of ancestralSassafrasoriginated from the thyrsoid-cymose inflorescence inCinnamomum. The Asian speciesS. tzumuandS. randaiensepossess bisexual flowers with two phenological phases, the AmericanS. albidumevolved unisexual flowers independently from other clades with unisexual flowers in the Lauraceae, i.e., the Laureae,Alseodaphnopsisin the Perseeae and the unisexual clade in theOcoteacomplex of the Cinnamomeae.

Multiple historic sources were used to reconstruct the forests of the Chesapeake at the time of European colonization. Early written records (1588–1699) show forests composed of hardwoods and conifers; the most commonly reported hardwoods are oak (100% occurrence in the texts), followed by walnut (93.3%), sassafras (86.7%), mulberry (80.0%), ash (60.0%), and chestnut (60.0%), and the most commonly reported conifers cedar (92.9%), pine (86.7%), and cypress (73.3%). It is likely that these reports focused on trees of economic value. John Smith’s 1612 map of the Chesapeake shows a forest composed of ca. 50:50 ratio of hardwoods to conifers. Hardwoods could not be identified further, while conifers could be grouped into what appear to be pine, cedar, and baldcypress. Advertisements of land for sale or lease (1751–1838) show a forest primarily composed of hardwoods (86.5%), predominantly oak, with a small conifer component (13.5%). Forest cover averaged 61.5% and ranged from 19.7 to 100%. There is no relationship between percentage of forest cover and date of advertisement, indicating little change over that time frame on settled land. Advertisements of wood for sale or wanted also indicate a forest dominated by oak. Oak was the primary material for ship construction and barrel making, as well as the major fuel source. Witness tree records from the seventeenth century (the earliest reported) on Maryland’s Eastern Shore show that a mature Oak–Pine forest dominated the pre-settlement forest, with white oak (Quercus alba) the most common hardwood. Currently a Pine–Oak–Maple forest dominates the landscape, with pines the dominant conifer and maple, particularly red maple (Acer rubrum), the dominant hardwood, mainly due to fire suppression in the twentieth century.

Background Prescribed fire in Eastern deciduous forests has been understudied relative to other regions in the United States. In Pennsylvania, USA, prescribed fire use has increased more than five-fold since 2009, yet forest response has not been extensively studied. Due to variations in forest composition and the feedback between vegetation and fire, Pennsylvania deciduous forests may burn and respond differently than forests across the eastern US. We measured changes in forest structure and composition up to eight years after prescribed fire in a hardwood forest of the Ridge and Valley region of the Appalachian Mountains in central Pennsylvania. Results Within five years post fire, tree seedling density increased more than 72% while sapling density decreased by 90%, midstory density decreased by 46%, and overstory response varied. Following one burn in the mixed-oak unit, overstory tree density decreased by 12%. In the aspen–oak unit, where pre-fire harvesting and two burns occurred, overstory tree density increased by 25%. Not all tree species responded similarly and post-fire shifts in species relative abundance occurred in sapling and seedling size classes. Abundance of red maple and cherry species decreased, whereas abundance of sassafras, quaking aspen, black oak, and hickory species increased. Conclusions Forest composition plays a key role in the vegetation–fire relationship and localized studies are necessary to measure forest response to prescribed fire. Compositional shifts in tree species were most pronounced in the aspen–oak unit where pre-fire overstory thinning and two prescribed fires were applied and significant structural changes occurred in all stands after just one burn. Increases in fire-tolerant tree species combined with reductions in fire-intolerant species highlight the role of prescribed fire in meeting management objectives such as altering forest structure and composition to improve game habitat in mid-Atlantic hardwood forests.

The effects of cadmium stress on the growth and physiological characteristics of Sassafras tzumu Hemsl. were studied in pot experiments. Five Cd levels were tested [CT(Control Treatment) : 0 mg/kg, Cd5: 5 mg/kg, Cd20: 20 mg/kg, Cd50: 50 mg/kg, and Cd100: 100 mg/kg]. The growth and physiological characteristics of the sassafras seedlings in each level were measured. The results showed that soil Cd had negative influences on sassafras growth and reduced the net growth of plant height and the biomass of leaf, branch and root. Significant reductions were recorded in root biomass by 18.18%(Cd5), 27.35%(Cd20), 27.57%(Cd50) and 28.95%(Cd100). The contents of hydrogen peroxide decreased first then increased while malondialdehyde showed the opposite trend with increasing cadmium concentration. Decreases were found in hydrogen peroxide contents by 10.96%(Cd5), 11.82%(Cd20) and 7.02%(Cd50); increases were found in malondialdehyde contents by 15.47%(Cd5), 16.07%(Cd20) and 7.85%(Cd50), indicating that cadmium stress had a certain effect on the peroxidation of the inner cell membranes in the seedlings that resulted in damage to the cell membrane structure. Superoxide dismutase activity decreased among treatments by 17.05%(Cd5), 10,68%(Cd20), 20.85%(Cd50) and 8.91%(Cd100), while peroxidase activity increased steadily with increasing cadmium concentration; these results suggest that peroxidase is likely the main protective enzyme involved in the reactive oxygen removal system in sassafras seedlings. Upward trends were observed in proline content by 90.76%(Cd5), 74.36%(Cd20), 99.73%(Cd50) and 126.01%(Cd100). The increase in proline content with increasing cadmium concentration indicated that cadmium stress induced proline synthesis to resist osmotic stress in the seedlings. Compared to that in CT, the soluble sugar content declined under the different treatments by 32.84%(Cd5), 5.85%(Cd20), 25.55%(Cd50) and 38.69%(Cd100). Increases were observed in the soluble protein content by 2.34%(Cd5), 21.36%(Cd20), 53.15%(Cd50) and 24.22%(Cd100). At different levels of cadmium stress, the chlorophyll content in the seedlings first increased and then decreased, and it was higher in the Cd5 and Cd20 treatments than that in the CT treatment. These results reflected that cadmium had photosynthesis-promoting effects at low concentrations and photosynthesis-suppressing effects at high concentrations. The photosynthetic gas exchange parameters and photosynthetic light-response parameters showed downward trends with increasing cadmium concentration compared with those in CT; these results reflected the negative effects of cadmium stress on photosynthesis in sassafras seedlings.

Sassafras albidum is an important tree species that occurs across North America. The presence of benzylisoquinoline and aporphine alkaloids has been previously described; however, the spatial distribution of these compounds within S. albidum and other plants of Lauraceae family is still unclear. Mass spectrometry imaging has become an important tool in analysis of plants metabolites, uncovering important contributions about the functional role, biosynthetic pathway, and accumulation of these compounds in the plant. This work aimed to identify further alkaloids present in S. albidum roots, twigs, and leaves by high-performance thin-layer chromatography coupled to desorption electrospray ionization multistage mass spectrometry (HPTLC DESI-MSn ) and to map the spatial distribution of these compounds by DESI-MS imaging. A total of 12 alkaloids were indentified in the roots and twigs, and six of them were detected for the first time in S. albidum. A high number of alkaloids was found in S. albidum roots; however, alkaloids were not detected in the leaves. Cross sections of roots and twigs were blotted onto TLC plates assisted by heating and solvent extraction, and these imprints were analyzed by DESI-MS imaging. The profile of alkaloid spatial distribution in DESI-MS images showed different accumulation patterns across and within different plant parts. Most alkaloids displayed higher intensities in the outer-most layer of the roots and twigs. The detailed spatial localization pattern of these alkaloids analyzed by DESI-MS imaging in different plant parts could contribute to a better understanding of the profile of distribution, accumulation, and biosynthesis of benzylisoquinoline and aporphine alkaloids.

Sassafras tzumu (Chinese sassafras) is an economically and ecologically important deciduous tree species. Over the past few decades, increasing market demands and unprecedented human activity in its natural habitat have created new threats to this species. Nonetheless, the distribution of its habitat and the crucial environmental parameters that determine the habitat suitability remain largely unclear. The present study modeled the current and future geographical distribution of S. tzumu by maximum entropy (MAXENT) and genetic algorithm for rule set prediction (GARP). The value of area under the receiver operating characteristic curve (AUC), Kappa, and true skill statistic (TSS) of MAXENT was significantly higher than that of GARP, indicating that MAXENT performed better. Temperate and subtropical regions of eastern China where the species had been recorded was suitable for growth of S. tzumu. Relative humidity (26.2% of permutation importance), average temperature during the driest quarter (16.6%), annual precipitation (12.6%), and mean diurnal temperature range (10.3%) were identified as the primary factors that accounted for the present distribution of S. tzumu in China. Under the climate change scenario, both algorithms predicted that range of suitable habitat will expand geographically to northwest. Our results may be adopted for guiding the preservation of S. tzumu through identifying the habitats susceptible to climate change.

Throughout eastern North America, oaks (Quercus) are a foundational tree species, but are regenerating poorly, particularly on mesic sites. This regeneration failure has spurred development of new management practices that create heterogeneous regeneration conditions that better match oak’s response to disturbances such as surface fire and windthrow. Expanding group shelterwood systems are designed to produce diverse regeneration conditions and have a high edge-to-forest interior ratio, where intermediate light levels may be beneficial for oak regeneration. We present data on early regeneration patterns from a large-scale experiment designed to assess the combined effects of these silvicultural systems and prescribed fire on oak regeneration, ecosystem resilience, and spatial and compositional heterogeneity in the Central Hardwood Region. Using transect-based surveys, we investigated the spatial patterns of woody regeneration within and outside of burned and unburned 2- or 3-stage group shelterwoods in factorial replicates at two different sites. Two years following the initial harvest, the south-facing site had substantial competitive oak regeneration just outside of the harvested groups on the northern, eastern, and western sides, but the east-facing site did not. On a stand level, tulip poplar (Liriodendron tulipifera) and sassafras (Sassafras albidum) regeneration increased in both sites, oak increased in the south-facing site, hickory (Carya) increased in the east-facing site, and maple (Acer) was relatively unaffected by the treatments. Competitive oak regeneration in the forest matrix just outside of the harvested groups in the south-facing site holds promise to regenerate a stand with a substantial oak component and high overall diversity, given the shelterwood groups will be expanded outward in successive entries and burned repeatedly over time.

During the aging of sugarcane spirit several chemical reactions occur. Therefore the aim of this work was to study the evolution of phenolic content, antioxidant activity and changes in color in organic sugarcane spirit aged in different woods for twelve months. The sugarcane spirit aged in barrels of jatobá showed higher levels of phenolic compounds and antioxidant activity (277.3 mg EAG.100 g-1 and -7.749 mg.L-1), followed by sassafras (83.8 mg EAG.100 g-1 and -0.299 mg.L-1) and ipê (67.6 mg EAG.100 g-1 and 4.180 mg.L-1). The colorimetric variables (brightness, chroma and metric hue angle) were significantly influenced by the species of the woods. Durante el envejecimiento de la cachaça, se producen varias reacciones químicas. Por lo tanto, el objetivo de este trabajo fue estudiar la evolución del contenido fenólico, la actividad antioxidante y los cambios en el color de la cachaça orgánica envejecida en diferentes maderas durante doce meses. La cachaça envejecida en barriles de jatoba mostró niveles más altos de compuestos fenólicos y actividad antioxidante (277.3 mg EAG.100 g-1 y -7.749 mg.L-1), seguido de sasafrás (83.8 mg EAG.100 g- 1 e - 0.299 mg.L-1) e ipe (67.6 mg EAG.100 g-1 y 4,180 mg.L-1). Las variables colorimétricas (brillo, croma y ángulo de sombra métrico) fueron influenciadas significativamente por las especies forestales. Durante o envelhecimento da cachaça, ocorrem várias reações químicas. Portanto, o objetivo deste trabalho foi estudar a evolução do conteúdo fenólico, atividade antioxidante e alterações na cor da cachaça orgânica envelhecida em diferentes madeiras por doze meses. A cachaça envelhecida em barris de jatobá apresentou maiores níveis de compostos fenólicos e atividade antioxidante (277,3 mg EAG.100 g-1 e -7.749 mg.L-1), seguida de sassafrás (83,8 mg EAG.100 g-1 e - 0,299 mg.L-1) e ipê (67,6 mg EAG.100 g-1 e 4.180 mg.L-1). As variáveis colorimétricas (brilho, croma e ângulo métrico da tonalidade) foram influenciadas significativamente pelas espécies da floresta.

We investigated the toxicity of selenium (Se) to the soil invertebrates Folsomia candida (Collembola) and Enchytraeus crypticus (potworm). Studies were designed to generate ecotoxicological benchmarks for developing ecological soil screening levels (Eco-SSLs) for risk assessments of contaminated soils. For the present studies, we selected Sassafras sandy loam, an aerobic upland soil with soil characteristics (low levels of clay and organic matter, soil pH adjusted from 5.2 to 7.1) that support high relative bioavailability of the anionic Se species that is typically found in aerobic soil. The Se was amended into soil as sodium selenate, subjected to weathering and aging using 21 d of alternating cycles of air-drying/rehydration to 60% of the water-holding capacity of the Sassafras sandy loam soil, under ambient greenhouse conditions. Effective concentrations at 20 and 50% (EC20 and EC50) levels for production of juveniles (reproduction) were 4.7 and 10.9 mg of Se/kg of soil (dry mass basis), respectively, for Collembola, and 4.4 and 6.2 mg/kg, respectively, for the potworms. The data enabled the derivation of toxicity benchmarks, contributing to the development of a soil invertebrate-based Eco-SSL of 4.1 mg/kg for Se. Environ Toxicol Chem 2018;37:846-853. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

In the past two decades, laurel wilt disease has significantly affected members of the Lauraceae in the southeast United States, causing widespread mortality of native redbay (Persea borbonia (L.) Spreng), and incidence of infections in avocado (Persea americana Mill.), sassafras (Sassafras albidum L.) and swamp bay (Persea palustris [Raf.] Sarg.) (Fraedrich et al., 2008, 2015, Olatinwo, et al. 2019). Laurel wilt is a vascular disease caused by Raffaelea lauricola (T.C. Harr., Fraedrich & Aghayeva), a fungus vectored by a non-native ambrosia beetle Xyleborus glabratus Eichhoff (Fraedrich et al. 2008). In August 2020, we investigated the mortality of a spicebush shrub (Lindera benzoin L.) (3.8 cm diameter at root collar, two m height) located ca. 17 mi northeast of Colfax, Grant Parish, Louisiana (31.750263° N, -92.643694° W). Evaluation of the dead shrub revealed brown, persistent foliage, and black vascular discoloration of the sapwood, typical symptoms of laurel wilt (Fig. S1). Although, beetle holes were observed on the sapwood, no beetle was found in galleries at the time. In the laboratory, a fungus consistently isolated from surface-sterilized sapwood tissues plated on potato dextrose agar (PDA) was identified as R. lauricola based on the morphological characteristics of the isolate (i.e., mucoid growth, conidiophores, and oblong/ovoid shape conidia [Harrington et al. 2008]). The fungal isolate was denoted as SB1. The identity of the fungus was confirmed by positive PCR amplification of the large subunit ribosomal RNA gene region using species-specific primers; rab-lsu-rl_F: CCCTCGCGGCGTATTATAG and rab-lsu-rl_R: GCGGGGCTCCTACTCAAA (Olatinwo, unpublished). The sequence of the isolate SB1 (GenBank Accession no. MW207371) showed 100% homology to the R. lauricola strain CBS 127349 sequence (GenBank Accession no. MH877933). The pathogenicity of SB1 on spicebush was evaluated on four healthy shrubs (average: 1 m height and 40 mm in diameter) at the location from which the original detection was made. Stems of two spicebush shrubs were inoculated with SB1 agar plugs from a 14-day old culture on PDA, while plain PDA plugs were used on the remaining two shrubs as non-inoculated controls. Agar plugs were placed in 5 mm (0.2 in) diameter hole punched on the bark with cork-borer as described by Mayfield et al (2008). After six weeks, the R. lauricola inoculated shrubs were wilted with noticeable blackened tissue discoloration in the sapwood, while the control trees remained healthy (Fig. S2). Raffaelea lauricola was re-isolated from tissue of the two inoculated, symptomatic shrubs, but not from the control trees. The sequence of the re-isolated R. lauricola isolate, denoted as SB3 (GenBank Accession no. MW207372), showed 100% homology to the R. lauricola strain CBS 127349 and isolate SB1. This first documentation of laurel wilt on spicebush in Louisiana is significant because, spicebush berries, leaves, and twigs are food sources for forest animals, birds, and insects including whitetail deer and spicebush swallowtail (Papilio troilus L.). Since its first report on sassafras in 2014 (Fraedrich et al. 2015), laurel wilt has spread across Louisiana on sassafras and swamp bay (Olatinwo et al. 2019) and has been confirmed in14 parishes. This report shows the relentless nature of the disease, as the pathogen moves from one vulnerable host to the next, expanding into new locations and threatening forest ecosystems across the southern United States.

Native Lauraceae (e.g. sassafras, redbay) in the southeastern USA are being severely impacted by laurel wilt disease, which is caused by the pathogen Raffaelea lauricola T. C. Harr., Fraedrich and Aghayeva, and its symbiotic vector, the redbay ambrosia beetle (Xyleborus glabratus Eichhoff). Cold temperatures are currently the only viable limitation to the establishment of X. glabratus in northern populations of sassafras. The observed lower lethal temperature of X. glabratus (− 10.0 °C) is warmer than its supercooling point (− 22.0 °C), indicating the beetle is a freeze intolerant and chill susceptible species. Empirically derived X. glabratus lower lethal temperature thresholds were combined with host distribution and microhabitat-corrected climate data to produce species distribution models for X. glabratus in the eastern USA. Macroclimate data (30-year mean annual minimum temperature) were corrected (− 1.2 °C) to account for thermal buffering afforded to X. glabratus while living inside sassafras trees. Only 0.1% of the current US sassafras spatial extent experiences sufficiently harsh winters (locales where mean annual minimum winter temperatures ≤ − 6.2 °C for ≥ 12 h) to exclude X. glabratus establishment in our species distribution model. Minimum winter temperatures will likely cause some X. glabratus mortality in ~ 52% of the current spatial extent of sassafras, although current data do not allow a quantification of X. glabratus mortality in this zone. Conversely, ~ 48% of the current spatial extent of sassafras is unlikely to experience sufficiently cold winter temperatures to cause any significant impediment to X. glabratus spread or establishment. A modest climate change scenario (RCP4.5) of + 1.4 °C would result in 91% of the current spatial extent of sassafras in the eastern USA occurring where winter minimum temperatures are unlikely to cause any mortality to X. glabratus.

Fire history reconstructions provide fire managers with valuable information regarding historical fire regime dynamics. Yet, in the Central Hardwood Forest Region (CHF), there is an absence of dendroecological studies where frequent wildfires have persisted into the twenty-first century. This study presents the first documented tree-ring reconstruction of fire history in the Pennsylvania anthracite coal-producing region. An approximately 150-year fire chronology was developed from fire-scarred pitch pine (Pinus rigida) and sassafras (Sassafras albidum) collected on Spring Mountain in Schuylkill County. Principal component analysis and k-means cluster analysis were used to identify four fire regime clusters based on interacting fire and non-fire parameters. Results indicate that fires occurred under a variety of moisture conditions and that a mid-twentieth century increase in fire activity on Spring Mountain was associated with the collapse of the regional anthracite industry and possibly amplified...

Sassafras albidum (Sassafras) is an ecologically important tree species that is widely distributed throughout the eastern United States. Sassafras is presently threatened by Raffaelea lauricola, a fungus vectored by Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae; Redbay Ambrosia Beetle), which causes a lethal vascular wilt known as laurel wilt disease (LWD). This study summarizes the status of Sassafras across the entire eastern United States and in areas with LWD in particular, so that LWD-induced changes in the Sassafras resource may be properly understood. Inventory data collected by the Forest Inventory and Analysis (FIA) Program of the US Department of Agriculture Forest Service indicated that as of 2013–2014 there were 1.9 billion live Sassafras trees and saplings across 28 states, 53 ecoregion sections, and 69 forest types in the eastern United States. Only 1.7% of Sassafras trees ≥2.5 cm diameter at breast height occurred in counties with LWD; an additional 2.8% occurred in ne...

The Pliocene flora of Frankfurt am Main described by Karl Mädler during the first half of the twentieth century is a key flora for the European Pliocene. In the present study, we revised the leaf fossil taxa described by Mädler and investigated plant material collected after Mädler’s publication. The revised and augmented floral list comprises seven new species and some new combinations of taxa described by Mädler. In total, 16 gymnosperm species in 15 genera and 73 angiosperm species (of which 15 could not be assigned to a genus) in 40 genera are recognised in the leaf record. Main characteristics of the flora are the high diversity of conifers, the diverse assemblage of exclusively deciduous Fagaceae, including six species of oaks, and the high diversity of Rosaceae. These features indicate cool temperate climatic conditions (comparable to Lugano in southern Switzerland). Angiosperm genera that are today confined to North America and/or East Asia (Eucommia,MagnoliaandSassafras) also are deciduous, whereas evergreen taxa are shrubs typical of the understorey (Buxus,Ilex,Pachysandra,Prunus lusitanicatype) andViscum. Eighteen taxa recorded in the Pliocene of Frankfurt am Main are today absent from western Eurasia and eastern North America, and 25 taxa are absent from western North America. This shows (i) a strong biogeographic link of the Pliocene flora of Frankfurt am Main with East Asia, (ii) surprisingly high levels of speciation (Pliocene endemisms) and (iii) that the European flora was more diverse in woody species shortly before the onset of major Pleistocene glaciations than today.

How were New World drugs received and understood in early modern England? In the seventeenth century, England’s first empire was being established and an increasing abundance of medicinal plants arrived in London from across the Atlantic. In this thesis, I argue that commercial and political imperatives drove the production, trade and consumption of New World medicines. I explore trends in the drug trade across the early modern period to identify how the scale and diversity of American medicines fluctuated in the English market. I recognise a critical juncture in the 1650s with a change in political institutions and the collapse of the colonial tobacco economy. In the case of Virginia, merchants and colonial statesmen advised the Parliamentarian government on new forms of plantation governance and economic development. Their recommendations included investment in perceived lucrative new commodities, such as sassafras, sarsaparilla and other medicinal plants. As the supply of American drugs expanded in the English market from the 1650s to the 1680s, medical writers became more engaged in the recommendation of New World medicaments for the treatment of diseases, including scurvy and venereal diseases. I consider the process of knowledge negotiation and commercial policymaking in issues surrounding the trade, propagation and transplantation of American medicinal plants into England during the late seventeenth century. The availability and consumption of New World drugs became commonplace by the early eighteenth century, and they could even be accessed by schoolboys and pensioners at charitable institutions. To formulate this narrative, I employ an integrated historical approach, drawing from economic, colonial, intellectual and medical history. I examine customs records, first-hand colonial accounts, printed books and pamphlets, manuscript commonplace books, letters, prescription lists and medical journals. This study contributes to research programmes on English colonial development, global commodities, the Columbian exchange and the early modern medical marketplace., This thesis was supported by the Wellcome Trust through a medical humanities doctoral studentship.

Extensive mortality of redbay (Persea borbonia (L.) Spreng.) has been observed in the southeastern United States since 2003. The mortality is due to laurel wilt caused by Raffaelea lauricola T. C. Harr., Fraedrich & Aghayeva, a fungal symbiont of the recently introduced redbay ambrosia beetle (RAB), Xyleborus glabratus Eichhoff (1,2). The wilt is known to affect other members of the Lauraceae including sassafras (Sassafras albidum (Nuttall) Nees) and avocado (Persea americana Mill.) (1,3). Two inoculation experiments were conducted to evaluate the susceptibility of California laurel (Umbellularia californica (Hook. & Arn.) Nutt.) to R. lauricola. Seedlings, averaging 73 cm high and 13 mm in diameter, were wounded with a drill bit (2.8 mm) to a depth of one-half the diameter of the stems. In each experiment, 10 seedlings were inoculated with one of two isolates of R. lauricola (five seedlings per isolate) obtained as previously described (1) from wilted redbays on Hilton Head Island, South Carolina and Fort George Island, Florida. In the first experiment, seedlings were inoculated with spore suspensions (0.1 ml) ranging from 1.9 to 2.3 × 106 spores/ml and produced as previously described (1). In the second experiment, seedlings were inoculated with mycelial plugs obtained from the edge of 10-day-old cultures growing on malt extract agar (MEA). Five seedlings in each experiment served as controls and were inoculated with sterile deionized water or plugs of sterile MEA. Inoculation points were wrapped with Parafilm M (Pechiney Plastic Packaging, Menasha, WI). Seedlings were grown in growth chambers (daytime temperature 26°C, nighttime 24°C, and a 15-h photoperiod) for 13 to 15 weeks. At the end of the first experiment, 7 of 10 seedlings inoculated with R. lauricola exhibited wilt that appeared as a dieback of a few to the majority of branches. Nine of the ten seedlings exhibited sapwood discoloration and the fungus was isolated from eight of these seedlings. At the end of the second experiment, 8 of 10 seedlings exhibited wilt that again appeared as a dieback of a few branches to most branches. All seedlings with wilt exhibited sapwood discoloration and the fungus was recovered from these seedlings. Two seedlings inoculated with R. lauricola exhibited no symptoms of disease and the fungus was not recovered. Control seedlings remained healthy in both experiments with no evidence of wilt or sapwood discoloration and R. lauricola was not isolated. These results indicate that California laurel is susceptible to laurel wilt caused by R. lauricola. Furthermore, the disease on California laurel may appear as a branch dieback affecting individual branches one at a time rather than a rapid wilt of the entire crown as is often observed in redbay (1). Currently, the RAB is not known to occur on the West Coast and it is also not known if this beetle is capable of attacking and producing brood on California laurel. Nonetheless, if the RAB and R. lauricola become established on the West Coast, laurel wilt could pose a serious threat to natural ecosystems as well as the avocado industry in California. References: (1) S. W. Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington et al. Mycotaxon 104:399, 2008. (3) A. E. Mayfield, III et al. Plant Dis. 92:976, 2008.

Laurel wilt is a lethal, nonnative vascular wilt disease of redbay (Persea borbonia), sassafras (Sassafras albidum), and other trees in the Lauraceae (1,4). It is caused by a fungus (Raffaelea lauricola) and transmitted by the redbay ambrosia beetle (Xyleborus glabratus), a nonnative insect first detected in Georgia in 2002 (1,2). Since introduction of the pathogen and vector (presumably from Asia), laurel wilt has caused extensive mortality to redbays in Georgia, Florida, and South Carolina (1). In June 2009, a landowner in Gautier, MS reported dead redbay trees. Signs and symptoms were identical to those reported for laurel wilt along the Atlantic Coast (wilted, bronze red foliage, and dark gray-to-black vascular discoloration) (1). Infected trees have subsequently been confirmed in and near the Pascagoula River Basin. Size of infected redbays ranged from 5 to 20 cm (diameter at breast height). No heavily decomposed or fallen redbays were noted. Many individual specimens exhibited extensive drying of stem wood and dry, wilted, light brown foliage. This indicates that introduction to the area may have occurred within the last 3 years. X. glabratus adults were collected (30°26′44.45″N, 88°39′41.83″W) in a Lindgren funnel trap baited with phoebe and manuka oil lures. Beetle identification was confirmed by USDA-APHIS, and voucher specimens were submitted to the Smithsonian National Museum of Natural History and the Mississippi Entomological Museum. Symptomatic redbay wood chips from the same location were surface sterilized and plated on cycloheximide-streptomycin malt agar and R. lauricola was isolated. A 1,026-bp portion of 18S rDNA (GenBank No. GQ996063) was amplified by PCR and sequenced using primers NS1 and NS4. BLASTn searches revealed perfect homology to R. lauricola isolate PL 697 (GQ329704). Two isolates of R. lauricola were recovered and prepared into separate spore suspensions (1 × 108 CFU/ml). Each isolate was inoculated into two healthy redbays. The inoculated redbays were placed in a growth chamber with two water-only controls. All inoculated plants, and none of the controls, exhibited wilt symptoms and died within 20 days. R. lauricola was recovered from the discolored sapwood of the inoculated plants, completing Koch's postulates. A model prediction for the natural dispersion of X. glabratus and R. lauricola estimated that these organisms may not reach Mississippi for 10 to 15 years (3). The current detection of laurel wilt in Mississippi is substantially ahead of this estimate. Currently, no records of laurel wilt have been reported from western Georgia, all of Alabama, or the panhandle of Florida. Confirmed locations in Mississippi are in Jackson County, along the Interstate 10 corridor and the Pascagoula River drainage. Due to the relatively large extent of the infestation (~64 km2, including hundreds of infected trees) eradication is not being attempted. Surveys, remote sensing, and phylogeographic analysis are underway to delineate the extent of infestation and discover the mode of introduction. The current outbreak of laurel wilt in Mississippi is likely the result of human transport of infested wood, either from Asia as a separate, new introduction or from previously infested areas in the southeastern United States. References: (1) S. W Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington et al. Mycotaxon 104:399, 2008. (3) F. Koch and W. Smith. Environ. Entomol. 37:442, 2008. (4) J. A. Smith et al. Plant Dis. 93:198, 2009.

Laurel wilt disease, caused by Raffaelea lauricola (T.C. Harr., Fraedrich & Aghayeva sp. nov.), which is a fungal symbiont of the nonnative redbay ambrosia beetle (Xyleborus glabratus Eichhoff), has caused widespread mortality of native redbay (Persea borbonia (L.) Spreng) in Georgia, South Carolina, and Florida since 2002. The disease has been noted on other species in the Lauraceae including sassafras in Georgia (1), and more recently, on avocado and camphor in Florida (4). Since 2005, wilted shoots, branch dieback, and tree death have been observed in sassafras trees (Sassafras albidum (L.)) in Liberty, McIntosh, Chatham, Effingham, Bulloch, Evans, and Screven counties in Georgia; Bamberg, Beaufort, Charleston, Colleton, Hampton, and Orangeburg counties in South Carolina; and Putnam County in Florida. Symptomatic sassafras trees ranged from 1 to 12 m high and 2.5 to 25 cm in diameter at breast height. In contrast to red bay trees that retain wilted foliage, symptomatic sassafras defoliate rapidly as trees wilt and die. Multiple symptomatic ramets originating from a common root system have been observed. Removal of bark from stem and root sections from wilted trees revealed black-to-brownish staining in the sapwood, characteristic of laurel wilt. Wood chips from symptomatic areas of branches and roots were surface sterilized and plated on cycloheximide-streptomycin malt agar as previously described (1) and R. lauricola was routinely isolated. Small subunit (18S) sequences from rDNA were amplified by PCR and sequenced using primers NS1 and NS4 (3) for isolates from sassafras from Florida and South Carolina. BLASTn searches revealed homology to Raffaelea sp. C2203 (GenBank Accession No. EU123076, 100% similarity) described by Fraedrich et al. (1) from redbay and later named R. lauricola (2). The small subunit rDNA sequences for these isolates have been deposited into GenBank ( http://www.ncbi.nlm.nih.gov/Genbank/index.html ) and assigned Accession Nos. EU980448 (Florida) and GQ329704 (South Carolina). Koch's postulates have been completed with R. lauricola on this host previously (1). Laurel wilt on sassafras often was geographically isolated from other symptomatic hosts in Georgia and South Carolina and appears to occur on this host independently of proximity to redbay. Further studies to determine the epidemiology of laurel wilt on sassafras, potential resistance, and impact on sassafras life history and distribution are needed. Given the clonal nature of sassafras, the disease would appear to have the potential to move through roots of trees once established in a stand. References: (1) S. W Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington et al. Mycotaxon 104:399, 2008. (3) M. A. Innis et al. PCR Protocols, A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (4) J. A. Smith et al. Plant Dis. 93:198, 2009.

Laurel wilt, caused by Raffaelea lauricola, a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, is responsible for extensive mortality of native redbays (Persea borbonia and P. palustris) in the coastal plains of the southeastern United States (1). The wilt also affects the more widespread sassafras, Sassafras albidum, particularly in areas where diseased redbays are common and populations of X. glabratus are high. Because sassafras stems were thought to lack chemicals that are attractive to the beetle, and sassafras tends to be widely scattered in forests, it was believed that the advance of the laurel wilt epidemic front might slow once it reached the edge of the natural range of redbay, which is restricted to the coastal plains of the Gulf and Atlantic Coasts (2). In July and August of 2011, wilt-like symptoms (i.e., wilted and dead leaves, and streaks of black discoloration in the xylem) were observed on 1 to 10 sassafras trees (15 to 23 cm diameter; 6 to 9 m height) at each of three locations, which were approximately 6 km from one another in Marengo Co., Alabama. Samples of the discolored wood from five trees were plated on malt agar amended with cycloheximide and streptomycin (CSMA), and a fungus morphologically identical to R. lauricola was isolated from each tree (1). For confirmation, a portion of the large subunit (28S) of the rDNA region of three of the isolates was sequenced (3); in each case, the sequence matched exactly that of other isolates of R. lauricola (EU123077) from the United States. Symptomatic trees were found at all three sites when revisited in April 2012, and approximately 20 sassafras trees in various stages of wilt were observed at one location, where only one diseased tree had been noted in 2011. Bolts were cut from the main stem of a symptomatic tree, and eggs, larvae, and adults of X. glabratus were commonly found in tunnels, and R. lauricola was isolated from the discolored xylem. Three container-grown sassafras saplings (mean height 193 cm, mean diameter 2.1 cm at groundline) were inoculated as previously described (1) with conidia (~600,000) from an isolate of R. lauricola. Three additional sassafras saplings were inoculated with sterile, deionized water, and all plants were placed in a growth chamber at 25°C with a 15-h photoperiod. Inoculated plants began to exhibit wilt symptoms within 14 days, and at 30 days all inoculated plants were dead and xylem discoloration was observed. Control plants appeared healthy and did not exhibit xylem discoloration. Pieces of sapwood from 15 cm above the inoculation points were plated on CSMA, and R. lauricola was recovered from all wilted plants but not from control plants. This is the first record of laurel wilt in Alabama and is significant because the disease appears to be spreading on sassafras in an area where redbays have not been recorded (see http://www.floraofalabama.org ). The nearest previously documented case of laurel wilt is on redbay and sassafras in Jackson Co., Mississippi (4), approximately 160 km to the south. The exact source of the introduction of X. glabratus and R. lauricola into Marengo Co. is not known. The vector may have been transported into the area with storms, moved with infested firewood, or shipped with infested timber by companies that supply mills in the area. References: (1) S. Fraedrich et al. Plant Dis. 92:215, 2008. (2) J. Hanula et al. Econ. Ent. 101:1276, 2008. (3) T. Harrington et al. Mycotaxon 111:337, 2010. (4) J. Riggins et al. Plant Dis. 95:1479, 2011.

In recent years, outbreaks of nonnative invasive insects and pathogens have caused significant levels of tree mortality and disturbance in various forest ecosystems throughout the United States. Laurel wilt, caused by the pathogen Raffaelea lauricola (T.C. Harr., Fraedrich and Aghayeva) and the primary vector, the redbay ambrosia beetle (Xyleborus glabratus Eichhoff), is a nonnative pest-disease complex first reported in the southeastern United States in 2002. Since then, it has spread across eleven southeastern states to date, killing hundreds of millions of trees in the plant family Lauraceae. Here, we examine the impacts of laurel wilt on selected vulnerable Lauraceae in the United States and discuss management methods for limiting geographic expansion and reducing impact. Although about 13 species belonging to the Lauraceae are indigenous to the United States, the highly susceptible members of the family to laurel wilt are the large tree species including redbay (Persea borbonia (L.) Spreng) and sassafras (Sassafras albidum (Nutt.) Nees), with a significant economic impact on the commercial production of avocado (Persea americana Mill.), an important species native to Central America grown in the United States. Preventing new introductions and mitigating the impact of previously introduced nonnative species are critically important to decelerate losses of forest habitat, genetic diversity, and overall ecosystem value.

Induction of cytochrome P450, glutathione S transferase (GST), and carboxylesterase (CoE) activity was measured in guts of the scarab Popillia japonica Newman, after consumption of single or mixed plant diets of previously ranked preferred (rose, Virginia creeper, crape myrtle and sassafras) or non-preferred hosts (boxelder, riverbirch and red oak). The goal of this study was to quantify activities of P450, GST and CoE enzymes in the midgut of adult P. japonica using multiple substrates in response to host plant suitability (preferred host vs non-preferred hosts), and single and mixed diets. Non-preferred hosts were only sparingly fed upon, and as a group induced higher activities of P450, GST and CoE than did preferred hosts. However, enzyme activities for some individual plant species were similar across categories of host suitability. Similarly, beetles tended to have greater enzyme activities after feeding on a mixture of plants compared to a single plant type, but mixing per se does not seem as important as the species represented in the mix. Induction of detoxification enzymes on non-preferred hosts, or when switching between hosts, may explain, in part, the perceived feeding preferences of this polyphagous insect. The potential consequences of induced enzyme activities on the ecology of adult Japanese beetles are discussed.

Walnut blight ( Xanthomonas arboricola pv. juglandis ) disease incidence was estimated on commercial plantings of presumed J. sigillata x Juglans regia hybrids in Guangxi (2013, near harvest; high expected disease pressure) and J. regia, J. sigillata and presumed J. sigillata x J. regia hybrids in Sassafras eastern Australia (2014, near harvest; moderate expected disease pressure). The disease incidence was compared to a model based on rainfall during leafing out developed earlier in Tasmania. The results indicated that in Sassafras the model worked well for J. regia and J. sigillata . However, in both Sassafras and Guangxi the levels of blight observed on the husks of near mature hybrids was well below that expected. These data are a preliminary suggestion that some J. sigillata x J. regia hybrids may contain useful resistance to walnut blight.

The combustion of sassafras wood (Sassafras tzumu Hemsl) was investigated based on thermogravimetric analysis coupled with fire propagation apparatus under different heating conditions. The activation energies for various conversions estimated by two different non-isothermal methods were in the range of 83.13–235.51 kJ/mol. Two regions were established: Region I is oxidative pyrolysis corresponding to α

Lignocellulose is the main component of forest litter. Due to the recalcitrance of coniferous litter, nutrient turnover is usually slower in coniferous plantations. Lignocellulose decomposition is reportedly rapid in mixed-species litter, but the underlying microbial metabolic pathways that may explain this rapid rate are not well-studied. We collected litter at 60, 150, 270, and 360 days after leaf fall at three plantation types: larch, sassafras, and larch/sassafras mixed plantations. We investigated the contents of lignocellulose components, enzyme activities, microbial communities, and potential genetic functional pathways related to lignocellulose degradation. Most rates of lignocellulose component degradation and enzyme activities in mixed litter during decomposition were significantly higher than in larch litter. The relative abundances of Betaproteobacteria and Dothideomycetes, which are involved in lignocellulose degradation, were significantly higher in mixed-species litter than in larch litter. Bacterial cellulose and hemicellulose, and fungal lignin degradation genes were significantly influenced by plantation forest type. Mantel tests showed that (i) the content of lignocellulose significantly correlated with bacterial and fungal community composition and enzyme activities, and (ii) fungal decomposers might be the main drivers of lignocellulose degradation in different litter types. Mixing larch and sassafras litter changed the composition of the microbial community and the lignocellulose-degradation gene complement, accelerated the decomposition of lignocelluloses, and restored soil quality.

To analyze the genetic diversities and structures of Sassafras tsumu and to explore their changing patterns at five different altitudes, Bioptic Qsep 100 DNA fragment analyzer combined with 13 SSR primers was applied. The results showed that S. tsumu in Tianmushan Mountain had a relatively high genetic diversity, with the expected heterozygosity (H采用13对SSR引物,运用Bioptic Qsep100全自动核酸分析系统,分析了天目山5个海拔檫木群体的遗传多样性和遗传结构及其在不同海拔下的变化模式.结果表明: 天目山檫木群体具有较高的遗传多样性水平,其中期望杂合度和观察杂合度分别为0.84和0.61.根据Shannon指数,天目山檫木中海拔(500～800 m)群体的遗传多样性水平大于低海拔(200 m)和高海拔(1100～1400 m)群体的遗传多样性水平.由基因分化系数和AMOVA分析可知,檫木种群的遗传变异主要存在于群体内.STRUCTURE分析和UPGMA聚类分析表明,中、低海拔被划为一个群体,而高海拔被划为另一个群体.低海拔和中海拔檫木群体遗传距离的差异表明,人为干扰对物种多样性具有负面效应,而自然保护区对物种多样性的保护起到了积极作用.

Laurel wilt disease (LWD), caused by the fungus Raffaelea lauricola and transmitted by Xyleborus glabratus (Redbay Ambrosia Beetle [RAB]), has killed millions of Persea borbonia (Redbay) trees throughout the southeastern Coastal Plain. Laurel wilt also has been detected in Sassafras albidum (Sassafras) in widely dispersed locations across the southeastern US. We established long-term laurel wilt disease-progression plots in Redbay and Sassafras stands in southeastern Georgia and monitored them through 4 years to document mortality rates and investigate long-term effects of LWD on Redbay and Sassafras survival and regeneration. Laurel wilt disease killed 87.3% of Redbay and 79.5% of Sassafras trees in the plots. The time from initial LWD detection to inactivity (no new mortality) in Redbay stands ranged from 1.1 to 3.6 years, with rate of disease progression positively related to host-tree size and abundance. Larger trees died at a higher rate in both Redbay and Sassafras stands, and mortality cur...

Laurel wilt disease is altering forests of the southeastern USA with widespread mortality to lauraceaous hosts, such as redbay (Persea borbonia (L.) Spreng.) and sassafras (Sassafras albidum (Nutt.) Nees). Sassafras is broadly distributed throughout the eastern USA and could serve as a pathway for laurel wilt disease spread into deciduous forests. The resulting invasion and widespread mortality of sassafras would affect these forests ecologically. In anticipation of this, we used preexisting vegetation data and the Forest Vegetation Simulator to predict future characteristics of invaded and noninvaded forests under two sassafras mortality scenarios, 33% and 99%. We calculated changes in total basal area and basal area of dominant species to assess the effects of invasion on forests of central Kentucky. We found that simulated sassafras mortality immediately resulted in significant declines to total basal area (0.87–2.32 m2/ha reductions) and also affected basal areas of selected species over time...

The naturally occurring Verticillium nonalfalfae has been proposed as a biocontrol agent against the highly invasive Ailanthus altissima in the eastern United States. We tested 71 nontarget woody species for susceptibility to the potential biocontrol agent. In the field, only devil’s walkingstick (17% incidence) and striped maple (3%) acquired infections through natural spread from infected A. altissima (100%). Staghorn sumac (16% incidence) also exhibited wilt in close proximity to diseased Ailanthus, although V. nonalfalfae was never recovered. Stem inoculations, which are highly artificial in that they bypass root defenses and flood the xylem with millions of conidia, induced varying levels of wilt and mortality in 10 nontarget species from which V. nonalfalfae was reisolated, although recovery and crown rebuilding occurred following initial wilt in several species including sassafras and northern catalpa. Thirty-seven of the 71 inoculated species exhibited vascular discoloration, although 23 of these species exhibited no outward symptoms (wilt, dieback) for up to 6 years postinoculation. However, V. nonalfalfae was reisolated from three of the 23 species, indicating a tolerant host response. Our results suggest that V. nonalfalfae is generally host-adapted to A. altissima with 78 of 78 A. altissima seed sources from 26 states and Canada showing susceptibility, and offers support for adoption and dissemination of V. nonalfalfae to combat the highly invasive A. altissima.

We investigated individual toxicities of the nitrogen-based energetic materials (EMs) 2,4-dinitrotoluene (2,4-DNT); 2-amino-4,6-dinitrotoluene (2-ADNT); 4-amino-2,6-dinitrotoluene (4-ADNT); and nitroglycerin (NG) on microbial activity in Sassafras sandy loam (SSL) soil, which has physicochemical characteristics that support very high qualitative relative bioavailability for organic chemicals. Batches of SSL soil for basal respiration (BR) and substrate-induced respiration (SIR) assays were separately amended with individual EMs or acetone carrier control. Total microbial biomass carbon (biomass C) was determined from CO

We investigated the effects of nitramine explosive CL-20 (China Lake compound 20) on the indigenous soil invertebrate community in Sassafras sandy loam (SSL) soil using a 12-week soil microcosm assay. Freshly collected SSL soil was amended with CL-20 to prepare multiple treatment concentrations ranging from 0 (acetone control) to 10,300 mg kg−1. The selected concentration range of CL-20 adequately assessed the concentration–response relationships for total microarthropods, and for individual microarthropod groups. The overall composition of microarthropod community in SSL soil was not affected by exposure to CL-20, based on the number of taxonomic groups present in the individual treatments after 12 weeks. However, community structure analysis revealed greater sensitivity to CL-20 by predatory mesostigmatid mites. Microarthropod and nematode communities showed contrasting sensitivities to CL-20 in SSL soil. Total numbers of nematodes were either unaffected or significantly (p

Successful canopy recruitment is one of the most important components of sustainable forestry practices. For many desirable species in oak-dominated forests, insufficient sapling growth is a common limitation to successful recruitment. The objectives of this study were to (i) examine the impact of overstory density on sapling growth in the Missouri Ozarks, (ii) investigate the potential for overstory retention to promote compositional shifts via interspecific differences in sapling height growth, and (iii) compare the use of mean and near-maximum growth rates to quantify the impact of overstory density on sapling growth and height differentiation among species. We found that the periodic annual height increment of saplings decreased with increasing overstory density for all species groups in this study (red oaks (Quercus spp.), white oaks (Quercus spp.), hickories (Carya spp.), sassafras (Sassafras spp.), blackgum (Nyssa spp.), dogwood (Cornus spp.), red maple (Acer spp.), ashes (Fraxinus spp.), and elms (Ulmus spp.)). There was evidence of interspecific differentiation in growth rates during the sapling stage, and the observed differences were more pronounced at low overstory densities. Increasing overstory densities either reduced or eliminated the differences in growth among species. Although red oaks displayed the greatest maximum growth rates of all species under low overstory densities (2·ha−1), the growth advantage of red oaks was reduced with increasing overstory density. This may provide opportunities to shift species composition toward white oaks using partial harvesting regimes in the Missouri Ozarks. However, white oaks had little to no advantage in height growth over many competing species when overstory density exceeded about 10 m2·ha−1. This implies that the probability of recruitment under overstory densities greater than about 10 m2·ha−1is likely to decline for all oaks in the Missouri Ozarks. We found that using the 90th quantile of height growth rates to evaluate the impact of overstory density on sapling growth had two potential advantages over using the mean growth rate: (i) it provided better models of the limiting effects of overstory density on sapling height growth, and (ii) the focus was on the growth rates of stems that were most likely to recruit into the canopy.

Elk (Cervus canadensis) can significantly alter plant community composition and reduce plant biodiversity, mass, seedling numbers and sapling growth. Yet, few studies have examined the interactions of reintroduced elk with woody plant communities in eastern North America. To test the hypothesis that elk herbivory would reduce woody plant diversity and recruitment and also change woody plant community composition when compared to deer, we evaluated herbivory effects of a captive elk herd and a free-roaming white-tailed deer (Odocoileus virginianus) population in Land Between the Lakes National Recreation Area in western Kentucky. Elk and deer herbivory did not differ in their effects upon overall woody plant diversity. However, elk browsing significantly altered woody plant community composition (F1,15 = 2.27, P = 0.005), reduced stem heights of Quercus and Cornus genera (Ps < 0.036) and reduced frequencies of Quercus, Nyssa, and Sassafras (Ps < 0.045) when compared to deer. Our results sugges...

Lindera Thunb. (Lauraceae) consists of approximately 100 species, mainly distributed in the temperate and tropical regions of East Asia. In this study, we report 20 new, complete plastome sequences including 17 Lindera species and three related species, Actinodaphne lancifolia, Litsea japonica and Sassafras tzumu. The complete plastomes of Lindera range from 152,502 bp (L. neesiana) to 154,314 bp (L. erythrocarpa) in length. Eleven small inversion (SI) sites are documented among the plastomes. Six of the 11 SI sites are newly reported and they locate in rpoB-trnC, psbC-trnS, petA-psbJ, rpoA and ycf2 regions. The distribution patterns of SIs are useful for species identification. An average of 83 simple sequence repeats (SSRs) were detected in each plastome. The mono-SSRs accounted for 72.7% of total SSRs, followed by di- (12.4%), tetra- (9.4%), tri- (4.2%), and penta-SSRs (1.3%). Of these SSRs, 64.6% were distributed in an intergenic spacer (IGS) region. In addition, 79.8% of the SSRs are located in a large single copy (LSC) region. In contrast, almost no SSRs are distributed in inverted repeat (IR) regions. The SSR loci are useful to identifying species but the phylogenetic value is low because the majority of them show autapomorphic status or highly homoplastic characteristics. The nucleotide diversity (Pi) values also indicated the conserved nature of the IR region compared to LSC and small single copy (SSC) regions. Five spacer regions with high Pi values, trnH-psbA, petA-psbJ and ndhF-rpl32, rpl32-trnL and Ψycf1-ndhF, have a potential use for the molecular identification study of Lindera and related species. Lindera species form a paraphyletic group in the plastome tree because of the inclusion of related genera such as Actinodaphne, Laurus, Litsea and Neolitsea. A former member of tribe Laureae, Sassafras, forms a clade with the tribe Cinnamomeae. The SIs do not affect the phylogenetic relationship of Laureae. This result indicated that ancient plastome captures may have contribute to the mixed intergeneric relationship of Laureae. Alternatively, the result may indicate that the morphological characters defined the genera of Lauraceae originated for several times.

Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) and sassafras trees that died from laurel wilt were discovered in a 3-parish area of northern Louisiana, USA, in Sep 2014. Redbay, a species that has been severely affected by the disease in the coastal plains forests of the southeastern USA, is not found in this area of northern Louisiana, suggesting that sassafras is attractive to X. glabratus and an adequate reproductive host for the beetle. This is the first report of X. glabratus and laurel wilt in Louisiana and the first report of the beetle and disease west of the Mississippi River. Sumario En septiembre del 2014, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) y arboles de sasafras que murieron a causa de la marchitez del laurel fueron descubiertos en un area de 3 municipios del norte de Louisiana, EE.UU. El aguacatillo ( Persea borbonia ), una especie que se ha visto gravemente afectada por la enfermedad en los bosques de la llanura costero del sudeste de EE.UU., no se encuentra en esta zona del norte de Louisiana, lo que sugiere que el sasafras es atractivo para X. glabratus y un hospedero reproductivo adecuado para el escarabajo. Este es el primer informe de X. glabratus y la marchitez del laurel en Louisiana y el primer informe del escarabajo y la enfermedad al oeste del rio Mississippi. View this article in BioOne

The redbay ambrosia beetle, Xyleborus glabratus Eichoff, (Coleoptera: Curculionidae: Scolytinae) is a severe pest of North American trees and shrubs in the family Lauraceae. Supercooling point (SCP) is an important physiological baseline for cold tolerance studies and could provide useful insights into the invasive potential of X. glabratus in northern latitudes of North America. The supercooling point (SCP) of X. glabratus was experimentally determined on field-collected and artificially cold hardened specimens. Field-collected beetles were captured in Jackson County, Mississippi using Lindgren funnel traps baited with manuka oil lures. Testing was conducted from June through August 2011. The mean SCP for field-collected X. glabratus was -21.7 ± 0.5 °C (± SE). A significant negative trend in the SCPs of field-collected beetles occurred over the summer testing period. Xyleborus glabratus specimens were reared from redbay (Persea borbonia (L.) Sprengel bolts in June 2012 and artificially cold hardened in a low temperature incubator at a thermo-photoperiod of 7 °C:2 °C (10:14 h L:D) for 31 days. Artificially cold hardened X. glabratus supercooled to a mean temperature of -23.9 ± 0.4 °C (± SE), which was significantly lower than that of field-collected beetles. Biometric indices of beetles (size, weight, and size x weight interaction) had no effect on the mean supercooling SCPs of either field-collected or artificially cold hardened beetles. Results from environmentally conditioned beetles suggest that X. glabratus has a high degree of thermal plasticity. Based on the artificially cold hardened mean SCP, X. glabratus and laurel wilt disease have the possibility to impact sassafras and northern spicebush throughout eastern North America. The data, although preliminary, suggests that a previous spatio-temporal model based on climate match data may have substantially underestimated the geographical area that may be affected by X. glabratus. This study will help form the basis of building and validating models to better predict the North American invasion potential of X. glabratus.

UNLABELLED PREMISE OF THE STUDY We investigate factors supporting the persistence in southern China of a rare Tertiary relict tree species, Liriodendron chinense, which has been almost eliminated by recent land use conversion. We hypothesize that cultural practices and traditional sustainable forest resource uses provide niches for the species' regeneration that will complement infrequent natural disturbances, while the species' survival on remote mountain slopes where there are no humans depends on natural disturbances alone. • METHODS We examined and analyzed various landscape contexts, community associations, age distributions, and regeneration patterns of Liriodendron chinense. • KEY RESULTS Forest communities containing Liriodendron chinense were of three types: (1) village fengshui forests-mature forests dominated by Tertiary relict taxa Liriodendron, Toona, and Emmenopterys, protected for their supposed spiritual value; (2) young secondary forests near villages, dominated solely by Liriodendron; and (3) old secondary forest remnants on mountain slopes far from villages, dominated by Liriodendron with other Tertiary relicts of the genera Davidia and Sassafras. The age structure of Liriodendron indicated ample recruitment in the first two forest types, where the activities of local people have provided regeneration niches for the survival of this shade-intolerant pioneer species. On the remote mountain slopes that have never been converted to agriculture, Liriodendron has survived through regeneration made possible by natural disturbances. • CONCLUSIONS The traditional human land use, influenced by cultural values, has supplemented infrequent natural disturbances, providing regeneration niches for this and other Tertiary remnant species near villages in mountain valleys, while on uninhabited mountain slopes the species depends on natural disturbances to survive.

A flora from Thomas Ranch near Princeton, British Columbia, Canada, is assessed for biodiversity and paleoclimate. This latest Early to early Middle Eocene flora occurs in the Allenby Formation. Seventy-six megafossil morphotypes have been recognized, representing at least 62 species, with 29 identified to genus or species. Common taxa include Ginkgo L., Metasequoia Miki, Sequoia Endl., Abies Mill., Pinus L., Pseudolarix Gordon, Acer L., Alnus Mill., Betula L., Fagus L., Sassafras J Presl, Macginitiea Wolfe & Wehr, Prunus L., and Ulmus L. More than 70 pollen and spore types are recognized, 32 of which are assignable to family or genus. The microflora is dominated by conifers (85%–97% abundance), with Betulaceae accounting for most of the angiosperms. The Climate Leaf Analysis Multivariate Program (CLAMP) calculates a mean annual temperature (MAT) of 9.0 ± 1.7 °C and bioclimatic analysis (BA) calculates a MAT of 12.8 ± 2.5 °C. Coldest month mean temperature (CMMT) was >0 °C. Mean annual precipitation (MAP) was >70 cm/year but is estimated with high uncertainty. Both the CLAMP and BA estimates are at the low end of the MAT range previously published for other Okanagan Highland localities, indicating a temperate climate consistent with a mixed conifer–deciduous forest.

The redbay ambrosia beetle Xyleborus glabratus Eichhoff is a non-native vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern U.S.A. 2 Concern exists that X. glabratus and its fungal symbiont could be transported to the western U.S.A. and cause damage to California bay laurel Umbellularia californica (Hook. & Arn.) Nutt. in California and Washington. 3 The present study evaluated in-flight attraction, attack density and emergence of X. glabratus and another invasive ambrosia beetle Xylosandrus crassiusculus (Motschulsky) on cut bolts of California bay laurel and eight related tree species in an infested forest in South Carolina. Xylosandrus crassiusculus is not a vector of the laurel wilt pathogen but is a pest of nursery and ornamental trees. 4 Mean catch of X. glabratus on California bay laurel bolts was not significantly different from catches on bolts of known X. glabratus hosts sassafras Sassafras albidum (Nutt.) Nees and swampbay Persea palustris (Raf.) Sarg. Mean attack density and adult emergence of both beetle species from California bay laurel was equal to or greater than all other tree species tested. Both beetle species readily produced brood in California bay laurel bolts. 5 The results obtained in the present study suggest that California bay laurel may be negatively impacted by both of these invasive ambrosia beetles if they become established in the tree's native range.

Nowadays, the maize weevil Sitophilus zeamais—Motsch 1855 is the most relevant pest found during storage of maize grains. Aiming at protecting the agricultural crops, high amounts of synthetic pesticides are used around the world. In this sense, this work aimed at evaluating the insecticidal and repellent effect of essential oil of Ocotea odorifera (Vellozo) Rohwer (Lauraceae) (O. odorifera (sassafras)) leaves against the maize weevil in maize grains. The essential oil's chemical composition showed that sassafras contains camphor (43%) and safrole (42%) as major compounds. Our results show that sassafras oil was insecticidal and repellent to maize weevil. About 100% mortality was achieved using a concentration of 0.32 μl cm−2, after 24 h of exposure. The LD50 value was 14.1 μl or 0.09 μl cm−2 and the study of the effect on insect mortality at the lethal doses (LD50) showed that after 72 h mortality was 100%. The values of the preference index varied from −0.39 (0.065 μl cm−2) to −0.63 (0.659 μl cm−2), demonstrating that the plant oil presents repellent activity. The repellency bioassay simulating small bins showed the repellent effect level from 0.64 (0.36 μl cm−3) to 0.94 (2.9 μl cm−3). The essential oil of sassafras presented insecticidal and repellency against maize weevil. Although from an economical point of view synthetic chemicals are still more frequently used as repellents, natural products (essential oils) have the potential to provide efficient and safer repellents for humans and the environment.

A Aniba canelilla (H.B.K.) Mez é uma planta aromática proveniente da região amazônica cujo óleo essencial apresenta como componentes majoritários o 1-nitro-2-feniletano e o metileugenol. Apesar das atividades antifúngicas e anti-inflamatórias cientificamente comprovadas e do uso popular do óleo para o tratamento de dermatites, acnes e feridas, não existe até o momento um estudo que verse sobre a quantificação desses compostos na pele. O objetivo deste trabalho foi a validação de um método bioanalítico otimizado por microextração em fase sólida no modo headspace em cromatógrafo gasoso com detector de ionização de chama (HS-SPME-GC-FID) para a determinação do 1-nitro-2-feniletano e metileugenol a partir do óleo essencial em diferentes amostras de estudo de permeação cutânea in vitro. Uma metodologia foi desenvolvida e validada por HS-SPME-GC-FID. A faixa da curva de calibração foi de 2,08 - 207,87 μg.mL-1 para o 1-nitro-2-feniletano e de 0,40-40,41 μg.mL-1 para o metileugenol. A presença de matriz e as características intrínsecas da metodologia de HS-SPME requereram uma transformação da curva de calibração. A transformação logarítmica (Log10) foi então aplicada aos dados e os resultados apresentaram homocedasticidade, resíduos dispersos, coeficiente de determinação (r²> 0,99) e recuperação adequados. Estudos de permeação cutânea foram realizados em células de Franz com diferentes quantidades (20, 100 e 200 μL) de óleo essencial de A. canelilla para avaliar o perfil de permeação e retenção em pele de orelha suína e fluido receptor. A análise das amostras nas condições validadas mostrou uma grande permeação e retenção dos compostos na seguinte ordem: fluido receptor >> derme >> epiderme >> estrato córneo. Verificou-se um aumento progressivo e dependência na retenção com base na quantidade aplicada no compartimento doador e grande retenção principalmente no fluido receptor e derme, resultado este compatível com as características físico-químicas de Log P, afinidade ao ambiente hidrofílico e lipofílico, tamanho e peso molecular do 1-nitro-2-feniletano e metileugenol. Em conclusão, o método proposto por HS-SPME-GC-FID para quantificar os compostos majoritários do óleo essencial de A. canelilla em amostras de pele de orelha suína e fluido receptor foi seletivo, preciso, exato e adequado, e pode ser utilizado em análises futuras. Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane and methyleugenol as major compounds. Despite of the scientifically proved antifungal and anti-inflammatory activities and the popular use of oil for the treatment of dermatitis, acnes and wounds, there is no study up to date about the quantification of these compounds in skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid phase microextraction on headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of 1-nitro-2-phenylethane and methyleugenol from the essential oil in different samples of in vitro cutaneous permeation study. A methodology was developed and validated by HS-SPME-GC-FID. The ranges of calibration curves were 2.08 - 207.87 μg.mL-1 for 1-nitro-2-phenylethane and 0.40 - 40.41 μg.mL-1 for methyleugenol. The presence of matrix and the intrinsic characteristics of the HS-SPME methodology required a transformation to the calibration curves. The logarithmic transformation (Log10) was then applied to the data and the results showed homoscedasticity, dispersed residues, and adequate coefficient of determination (r²> 0.99) and recovery. Skin permeation studies were performed on Franz cells with different amounts (20, 100 and 200 μL) of A. canelilla essential oil to evaluate the skin permeation and retention profile in porcine ear skin and receptor fluid. The analysis of the samples under the validated conditions showed a high permeation and retention of the major compounds in the following order: receptor fluid >> dermis >> epidermis >> stratum corneum. A progressive increase and retention dependence were observed based on the amount applied in the donor compartment, and large retention mainly on the receptor fluid and dermis was observed, in accordance with the physicochemical characteristics of Log P, affinity to the hydrophilic and lipophilic environment, size and molecular weight of 1-nitro-2-phenylethane and methyleugenol. In conclusion, the method proposed by HS-SPME-GC-FID to quantify the major compounds of A. canelilla essential oil in porcine ear skin and receptor fluid samples was selective, accurate, precise and adequate, and can be used in future analyzes.

RESUMEN El género Persea tiene dos subgéneros, Persea y Eriodaphne. Existe controversia sobre la taxonomía entre las especies del subgénero Persea y su relación con el subgénero Eriodaphne. Debido a sus complejos patrones evolutivos, el subgénero Persea tiene considerable variabilidad con afinidades taxonómicas inciertas. En este estudio se analizaron las secuencias de la región trnL-trnF de DNA de cloroplastos, obtenidos de hojas de 38 accesiones, siete del subgénero Eriodaphne y 31 del subgénero Persea, además uno de Beilschmiedia. Un primer alineamiento con el espacio intergénico trnL-trnF, incluyó 12 individuos del género Persea y uno del género Beilschmiedia, que se alinearon con 26 secuencias del GenBank de 22 géneros de la familia Lauraceae y un género de la familia Hernandiaceae. En un segundo alineamiento con un fragmento de aproximadamente 900 pb que comprende el extremo 3' del gen trnLuaa que incluye un intron, el espaciador trnL-F y el extremo 5' del gel trnFgaa; se incluyó cuatro secuencias del GenBank, una de Persea americana (AY841669), y tres especies del género Sassafras. Lo anterior con el objetivo de inferir sus posibles relaciones filogenéticas y en especial la de los dos subgéneros. El análisis filogenético no fue congruente con la clasificación actual del género, donde se separó fuertemente los dos subgéneros Persea y Eriodaphne, mientras que el clado del subgénero Persea no mostró una agrupación por raza, al igual que por afinidad de especies. Lo encontrado soporta la hipótesis de que los subgéneros Persea y Eriodaphne deben considerarse como géneros independientes.

Analogues of the bioactive natural alkoxynaphthalene pycnanthulignene D were synthesized by an efficient method. The starting plant allylalkoxybenzenes (1) are easily available from the plant essential oils of sassafras, dill, and parsley. The target 1-arylalkoxynaphthalenes (5) exhibited antiproliferative activity in a phenotypic sea urchin embryo assay.

The survival and growth of oak advance regeneration is often limited by shade-tolerant species that are abundant in the understory of oak stands. Evidence of historic burning has prompted the use of prescribed fire as a tool to improve the competitive status of oak regeneration in mature stands. A primary shortfall of fire effects research in oak forests has been a lack of long-term studies on the effects of multiple fires. Here we describe the effects of repeated fires on stand structure and tree regeneration over a 13year period in mature mixed-oak forests located in southern Ohio, USA. Three stands were burned 3–5 times from 1996 to 2005 with low-intensity dormant-season fires, and two stands remained unburned. Woody vegetation was sampled periodically on nine 0.125 ha plots per stand. Plots were located across the upland landscape and were characterized by an Integrated Moisture Index. Fire altered stand structure by reducing the density of large saplings (3.0–9.9 cm DBH) and midstory trees (10–25 cm DBH) by 76% and 34%, respectively. Fire had little impact on trees >25 cm DBH. Small saplings (1.4 m tall to 2.9 cm DBH) were dynamic over time on dry plots that were burned. After being repeatedly topkilled from year 1–8, the small sapling layer had redeveloped on dry burned plots by year 13 and species composition had shifted from dominance by shade-tolerant species to a more equal distribution of shade-tolerants, oaks + hickories, and sassafras. The density of oak + hickory and sassafras advance regeneration (stems 30 cm tall to 2.9 cm DBH) was significantly greater on burned plots than on unburned plots in year 13, though variability among plots was high. Advance regeneration of shade-tolerant species was equally abundant on burned and unburned plots. Density of oak + hickory advance regeneration in year 13 was positively related to its weighted frequency (a surrogate for size and abundance) in year 0 (r 2 = 0.67, p < 0.0001) and inversely related to stand density (r 2 = 0.33, p < 0.0001) and canopy cover (r 2 = 0.31, p < 0.0001), both of which were reduced by fire. Although oak + hickory advance regeneration was more abundant on burned plots, we conclude that other methods (e.g., herbicide, partial cutting) are necessary to further reduce stand density and promote the development of larger oak + hickory regeneration, particularly on mesic sites. Published by Elsevier B.V.

Ice storms are one of the main causes of disturbance and mortality in oak forests and can occur more frequently than wind storms, fire, diseases, and insect outbreaks. The effects of the 2009 ice storm on the tree species were studied in an upland oak-hickory forest at Bernheim Forest, Kentucky. Approximately 14% of the trees showed some damage from the ice storm with Ostrya virginiana, Acer rubrum, and Quercus rubra being the most susceptible to damage. Quercus velutina, Quercus alba, and Sassafras albidium were least susceptible. Pole size trees were more vulnerable to damage than sapling and sawtimber. Trees found in the midstory, and on the eastern slope had more damage from the ice storm than the other trees. Immediately following the ice storm, seedlings showed a high mortality, and it took until 2011 before most species returned to pre ice storm levels. Seedling numbers did not return to pre ice storm levels on the ridgetop and western upper slopes, which are more vulnerable to drought. By damaging the A. rubrum more than the Quercus and Carya species, and opening the understory, the ice storm is reducing midstory canopy and may be changing the composition of upland oak forests.

Redbay ambrosia beetle (RAB), Xyleborus gla bratus Eichhoff (Coleoptera: Curculionidae: Sco lytinae), a native of Asia, was first discovered in the USA near Savannah, Georgia in 2002 (Haack 2001; Rabaglia et al. 2006). RAB is an effective vector of Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Harrington et al. 2008) that causes laurel wilt (LW), a lethal disease of several trees in the Lauraceae in the southeastern USA (Crane et al. 2008; Mayfield et al. 2008). Ambrosia beetle adults bore through the bark and into the xy lem (wood) where they lay eggs, then adults and larvae cultivate and feed on symbiotic ambrosia fungi that grow in the galleries. Native Persea (Laurales: Lauraceae) species appear to be pre ferred hosts. LW is responsible for high mortality of redbay [P borbonia (L.) Spreng.], swampbay [P palustris (Raf.) Sarg.], and sassafras [Sassa fras albidum (Nuttall) Nees] in Alabama, Flor ida, Georgia, Mississippi, North Carolina and South Carolina (Fraedrich et al. 2008; Hanula et al. 2008; Gramling 2010). As LW encroaches upon the Lake Wales Ridge ecosystem in south central Florida, silkbay (P. humilis Nash) is also showing susceptibility to LW and is dying. Addi tional species affected by LW include avocado (P. americana Mill.), spicebush [Lindera benzoin (L.) Blume], and other woody Lauraceae (Fraedrich et al. 2008) (Table 1). The susceptibility of 5 avocado cultivars of Mexican, Guatemalan or West Indian origin to RAB and LW was demonstrated by Mayfield et al. (2008). However, with more than 23 West In dian cultivars grown in Florida, it is necessary to determine their susceptibility. Moreover, as an adventive species to the North American conti nent, RAB might affect other valuable New World species. Most Persea species are of Mexican, Cen tral American, or South American origin. These Persea may have significant value in germplasm collections, some have been discovered recently, and some have resistance to diseases that afflict their commercial relative, the avocado (Skutch et l. 1992; Scora & Bergh 1992; Zentmyer & Schieber 1992). Thus, their susceptibility to RAB and LW warrants evaluation. Another member of the Lauraceae of much concern is the California bay laurel [Umbellularia californica (Hook. & Arn.) Nutt.], a dominant hardwood species of the U.S. Pacific Coast. Through inoculation experi ments, Fraedrich (2008) demonstrated that U. californica is susceptible to LW. With continued westward spread of LW, the host status of U. cali fornica needs to be confirmed. The 3 studies presented here evaluate sus ceptibility to RAB and LW in: 1) 13 West Indian avocado cultivars; 2) 10 non-commercial Persea spp., 1 Beilschmidia sp. (a genus related to Per sea), and 3) U. californica. First, no-choice ex periments were conducted to determine if RAB would bore into avocado cultivars not screened previously by Mayfield et al. (2008) and follow ing similar methodology. Avocado cultivars 'Ber necker', 'Beta', 'Brooks late', 'Choquette', 'Don nie', 'Dupuis', 'Hall', 'Loretta', 'Lula', 'Monroe', 'Simmonds', 'Tower 2' and 'Waldin' (4 plants each) were planted in 10-gallon pots in a screenhouse at he Plant Sciences Research and Education Unit, University of Florida (UF), Citra, Florida in VI 2008. Two plants of each cultivar were infested by enclosing 4 newly emerged 9 RAB (UF colony reared) within a mesh sleeve on the lower trunk. Two plants per cultivar were uninfested controls. Entrance holes and perseitol (white exudate from wounds) were monitored for 4 wk. Severity of wilt symptoms was scored using the following LW in dex: 0 = no wilt; 1 = wilt, no leaf necrosis; 2 = wilt, 10% necrosis or defoliation; 3 = wilt, 30% necrosis/ defoliation; 4 = 50% necrosis/defoliation; 5 = 75% necrosis/defoliation; 6 = 100% necrosis/defoliation

The Chilton Creek prescribed burn project was initiated in 1996 by The Nature Conservancy (TNC) to restore native oak woodlands and test the effect of frequent, low intensity surface fires conducted in the dormant season (March–April) on upland oak-hickory forests in the Ozarks of Missouri. Burning treatments on five sites totaling 1000 ha were initiated in 1998. The prescribed burn treatments included: annual burns (one site was burned annually) and periodic burns (four sites were burned with a mean fire return interval of approximately 4 years). Approximately 3000 stems of advance reproduction with basal diameters 615.0 cm were measured in 1997 (pre-burn), and remeasured in 1998, 2001 and 2007 as the prescribed burn treatments proceeded. Mortality and changes in average and aggregate total height between 1997 and 2007 were analyzed for fourteen selected tree species. Over a ten-year period prescribed burning reduced stem density, mean height and aggregate height by 57%, 36% and 67%, respectively. However, individual tree species responded differently to the repeated burns. Oaks exhibited moderate mortality (36–54%) compared to hickories, sassafras and winged elm, all of which experienced relatively low mortality (18–35%). Flowering dogwood, shortleaf pine, blackgum and other minor species incurred higher mortality (60–76%). Oaks generally had slightly lower reductions in mean height and aggregate height than associated species with the exception of shortleaf pine, but the differences were mostly non-significant. Repeated burning tended to favor the white oak species (white oak, post oak, chinkapin oak) more than the red oak species (black oak, scarlet oak), although the differences were minor. Shortleaf pine was the only species to show increases in mean height following the

Charcoal-tempered pottery is uncommon in North America, but was produced with notable frequency in Northeast Florida from ca. AD 300e600. Thirty-six thin sections of pottery were analyzed by petrographic analysis and compared to 10 clay samples in order to characterize the paste of charcoal-tempered wares in terms of charcoal and mineralogical composition and abundance, assess the number of clay sources used to make the pottery, identify the species of wood represented in charcoal inclusions, and infer techniques of ceramic production. This analysis identified four temper categories, three texture groups, and three distinct clay resources used to make charcoal-tempered pottery, all of which were likely local to Northeast Florida. Identified wood taxa include pine (Pinus sp.), cedar (cf. Juniperus sp.), cypress (cf. Taxodium sp.), and sassafras (Sassafras albidum), with pine suspected to be the most common. These genera of charred wood, which exhibit minimal shrinkage in the samples, along with the prevalence of bone and grog inclusions, indicate that hearth contents were processed as temper, sometimes in combination with quartz sand. Potential reasons for the use of hearth contents as temper are considered. 2011 Elsevier Ltd. All rights reserved.