White Oak Research Articles

Optimizing nature-based solutions by combining social equity, hydro-environmental performance, and economic costs through a novel Gini coefficient

A robust multi-functional framework for widespread planning of nature-based solutions (NBS) must incorporate components of social equity and hydro-environmental performance in a cost-effective manner. NBS systems address stormwater mitigation by increasing on-site infiltration and evaporation through enhanced greenspace while also improving various components of societal well-being, such as physical health (e.g., heart disease, diabetes), mental health (e.g., post-traumatic stress disorder, depression), and social cohesion. However, current optimization tools for NBS systems rely on stormwater quantity abatement and, to a lesser extent, economic costs and environmental pollutant mitigation. Therefore, the objective of this study is to explore how NBS planning may be improved to maximize hydrological, environmental, and social co-benefits in an unequivocal and equitable manner. Here, a novel equity-based indexing framework is proposed to better understand how we might optimize social and physical functionalities of NBS systems as a function of transdisciplinary characteristics. Specifically, this study explores the spatial tradeoffs associated with NBS allocation by first optimizing a local watershed-scale model according to traditional metrics of stormwater efficacy (e.g., cost efficiency, hydrological runoff reduction, and pollutant load reduction) using SWMM modeling. The statistical dispersion of social health is then identified using the Area Deprivation Index (ADI), which is a high-resolution spatial account of socioeconomic disadvantages that have been linked to adverse health outcomes, according to United States census properties. As NBSs have been shown to mitigate various adverse health conditions through increased urban greening, this improved understanding of geospatial health characteristics may be leveraged to inform an explicit representation of social wellness within NBS planning frameworks. This study presents and demonstrates a novel framework for integrating hydro-environmental modeling, economic efficiency, and social health deprivation using a dimensionless Gini coefficient, which is intended to spur the positive connection of social and physical influences within robust NBS planning. Hydro-environmental risk (according to hydro-dynamic modeling) and social disparity (according to ADI distribution) are combined within a common measurement unit to capture variation across spatial domains and to optimize fair distribution across the study area. A comparison between traditional SWMM-based optimization and the proposed Gini-based framework reveals how the spatial allocation of NBSs within the watershed may be structured to address significantly more areas of social health deprivation while achieving similar hydro-environmental performance and cost-efficiency. The results of a case study for NBS planning in the White Oak Bayou watershed in Houston, Texas, USA revealed runoff volume reductions of 3.45% and 3.38%, pollutant load reductions of 11.15% and 11.28%, and ADI mitigation metrics of 16.84% and 35.32% for the SWMM-based and the Gini-based approaches, respectively, according to similar cost expenditures. As such, the proposed framework enables an analytical approach for balancing the spatial tradeoffs of overlapping human-water goals in NBS planning while maintaining hydro-environmental robustness and economic efficiency.

Noninvasive Sonic Tomography for Detecting Internal Defects in Old, Large Oriental White Oak in Cultural Heritage Areas

Incidence rates of tree damage are increasing because of the increased intensity and frequency of abnormal climate events such as strong winds and heavy rains. Structural defects inside trees are difficult to detect by visual inspection; therefore, it is difficult to respond to them in advance based on prediction. Noninvasive sonic tomography (SoT) is a method that estimates internal defects while minimizing physical damage to trees; however, its accuracy differs depending on the species. Therefore, in this study, we aimed to compare the performance of noninvasive SoT and invasive resistance micro-drilling (RM) in detecting tree damage in oriental white oak (Quercus aliena Blume) distributed in East Asia and performed wood section analysis to verify the accuracy of noninvasive SoT. Linear regression analysis showed that defects in tomograms tended to increase with an increase in the number of defects in the RM profile, but the value of R2 was 0.405, which is lower than that of other tree species. The results from the wood section analysis and SoT were compared; the SoT tomograms appropriately reflected the location and size of the defects with a tendency to overestimate the defects when cracks were present, while the electric resistance tomography was effective for detecting incipient decay.

Long-Term Effects of Crop Tree Release on Growth and Quality in White-Oak (Quercus alba L.)-Dominated Stands

Abstract Crop tree release (CTR) can be an effective intermediate silvicultural treatment for culturing high-value stems in mixed hardwood stands. The lengthy rotation of hardwoods requires long-term evaluations if silvicultural treatment effectiveness is to be fully evaluated. Our study provides a 35-year evaluation of individual-tree and stand response to CTR imposed in small sawtimber-sized white-oak (Quercus alba L.)-dominated stands. The focus on white oak is justified based on the significant biologic and economic values of the species, and this study furthers our ability to optimize use of CTR as management tool for sustaining our oak resources. The replicated experiment included three treatment levels: 20 crop trees ac−1, 34 crop trees ac−1, and a control. Using a repeated-measures framework, we analyzed (1) how CTR affects growth and stem quality of white oak crop trees and (2) stand-level effects of CTR on basal area, stocking, and ingrowth. CTR increased crop tree diameter growth and proportion of crop trees reaching their maximum potential grade. However, crop tree diameter growth and proportion achieving maximum potential grade did not differ between the 20 and 34 crop trees ac−1 treatments. Finally, CTR stimulated stand-wide growth without altering the patterns of ingrowth density or species distributions.

A chromosome-scale genome assembly of the Mongolian oak (Quercus mongolica).

Mongolian oak (Quercus mongolica Fisch.) is an ecologically and economically important white oak species native to and widespread in the temperate zone of East Asia. Here, we present a chromosome-scale reference genome assembly of Q.mongolica, a representative white oak species, by combining Illumina and PacBio data with Hi-C mapping technologies that is the first reference genome created for an Asian oak. Our results showed that the PacBio draft genome size was 809.84Mb, with a BUSCO complete gene percentage of 92.71%. Hi-C scaffolding anchored 774.59Mb contigs (95.65% of draft assembly) onto 12pseudochromosomes. The contig N50 and scaffold N50 were 2.64 and 66.74Mb, respectively. Of the 36,553 protein-coding genes predicted in the study, approximately 95% had functional annotations in public databases. A total of 435.34Mb (53.75% of the genome) of repetitive sequences were predicted in the assembled genome. Genome evolution analysis showed that Q.mongolica is closely related to Q.robur from Europe, and they shared a common ancestor ~11.8million years ago (Ma). Gene family evolution analysis of Q.mongolica revealed that the nucleotide-binding site (NBS)-encoding gene family related to disease resistance was significantly contracted, whereas the ECERIFERUM 1 (CER1) homologous genes related to cuticular wax biosynthesis was significantly expanded. This pioneering Asian oak genome resource represents an important supplement to the oak genomics community and will improve our understanding of Asian white oak biology and evolution.

Tree-ring analysis of the Free Black Beech Church in Rush County, Indiana: A surviving relic of an Indiana African American farm community

The Beech Church is part of a historically significant cultural landscape created in the 1820s by Southern Free Blacks in central Indiana, USA. Despite the immense cultural importance of the building, no definitive build date was known, though several sources posited a post-Civil War date. The main goal of this investigation was to determine the construction date of the Church using tree-ring analysis. Additionally, dating the building would lead to the creation of local tree-ring chronologies (series of accurately dated and measured tree rings) for a region that has received little dendrochronological study. Samples were collected from the crawl space and attic of the building. The samples were prepared for dating following standard dendrochronological methodology (sanding, skeleton plotting, ring measurement). Dates were assigned to individual tree rings by crossdating. Twenty-nine samples were collected from 21 timbers; 28 were successfully crossdated. Beech, sycamore, tulip poplar, and white oak timbers were found in the structure. Beech and tulip poplar were the most collected species and yielded chronologies spanning from 1690 to 1853 (900 rings) and 1741 to 1853 (653 rings), respectively. The last ring formed/harvest date (ring adjacent to bark or wane) was 1854 for nine timbers. No sampled timbers had any rings dating later than 1854. We conclude that the Beech Grove Church was erected with timbers that were harvested after the spring of 1854 and prior to spring 1855.

Novel nest tree selection by a deciduous forest New World warbler

The Cerulean Warbler (Setophaga cerulea), a Neotropical migrant passerine, inhabits deciduous forests across the eastern and midwestern United States and Canada. Within this broad geographic distribution, Cerulean Warbler populations select specific tree species for nest placement and are known to use a variety of deciduous tree species depending on the population. In southern Indiana, Cerulean Warblers typically nest in white oak (Quercus alba), but we have documented 19 tree species used, all of which are deciduous species. During 2018 and 2019, we discovered 2 instances of Cerulean Warblers nesting in pine trees (Pinaceae) in southern Indiana. Our observations suggest that Cerulean Warblers may in some instances select atypical nest sites as long as specific microhabitat characteristics are present at the nest location.

Changes in white oak (Quercus alba) phytochemistry in response to periodical cicadas: Before, during, and after an emergence.

Periodical cicadas have mass emergences once every 13 or 17 years. Plants may need to upregulate defense production in response to an emergence. Defense production is energetically expensive, so plants may downregulate their production after periodical cicada populations dissipate. We examined the defensive responses in leaves, branches, and roots of a common host, white oak (Quercus alba), prior to, during, and after a 17‐year periodical cicada (Magicicada spp.) emergence in western Pennsylvania, United States. During the emergence, total tannins and condensed tannins increased in foliar tissue, while simultaneously decreasing in root tissue compared to the prior and subsequent years. Non‐structural carbohydrates were low prior to the mass emergence but were re‐allocated to belowground storage during the emergence year and dropped thereafter. In the year after the emergence, there was a relaxation of foliar defenses, and root defenses returned to pre‐emergence concentrations. We also tested for differences in damaged and undamaged branches on the same tree during (2019) and the year after the emergence (2020). Both damaged and undamaged branches had significantly greater chemical defenses (polyphenols, total tannins, and condensed tannins) during the emergence than in the following year when there was no emergence. We propose that re‐allocation of resources may help maximize oak tree fitness by moving resources away from areas that are not in immediate threat to areas that are under immediate threat. Changes in aboveground and belowground phytochemistry in response to periodical cicada mass emergences may help us better understand which resource re‐allocation strategies are used by plants to minimize the effects of insect emergencies.

A novel set of polymorphic chloroplast microsatellite markers for northern red oak (Q. rubra L.)

AbstractOaks are model species due to their importance in various ecosystems, worldwide distribution, high economic value and emerging genomic resources. As such, knowledge on population differentiation across their distribution range is of high importance for sustainable forest management. As in most angiosperms, chloroplasts are maternally (via seeds) inherited in oak species and acorns are dispersed over comparably short distances. Consequently, chloroplast markers reveal comparatively high differentiation between populations, making them highly viable for the analysis of historic migration patterns and the certification of reproductive material. Despite the existence of various white oak (section: Quercus) chloroplast markers, red oak (section: Lobatae) chloroplast markers remain limited. Northern red oak is one of the most important North American oak species and a widespread non-native plantation tree species in European forests. We took advantage of chloroplast genomes of Q. rubra L. and related oak chloroplast genomes to develop a set of robust and easy-to-use chloroplast microsatellite primers for northern red oak. Furthermore, we tested transferability of those novel red oak primer pairs to Q. robur L. and Q. petraea Matt. Liebl. The new set of fifteen polymorphic chloroplast microsatellite markers revealed three additional northern red oak haplotypes after screening 80 northern red oak individuals representing seven haplotypes, identified based on formerly available markers. Therefore, they provide a higher resolution of haplotypes as compared to currently available markers.

Tiny Tree‐Dwelling Turtles

Photo 1. Female spotted turtle ABK, who nested successfully in June after spending the 2019–20 winter inside the swamp white oak tree (Quercus bicolor) with multiple males. ABK also spent the following winter inside the oak tree hibernaculum. Photo credit: Roy Nagle. Photo 2. Male spotted turtle NVX in a shallow, soft-bottomed rivulet formed by flooding from a beaver dam. Beavers expand spotted turtle foraging habitats and provide aquatic corridors for movements among seasonal habitats and to prospective habitats. During 2021, this male rendezvoused inside the swamp white oak tree with other spotted turtles intermittently from March 14 to April 12 and then moved away to forage among shallow wetlands fortified by beavers. Photo credit: Roy Nagle. Photo 3. Young (a) and older (b) male spotted turtles: (a) AKV is ~8 years old, with relatively distinct growth annuli and new growth indicated by light-colored line down the middle of plastron; (b) BKV is considerably older and has a visible injury to his left pectoral scute. Like most older, sexually mature males in the population, BKV spent much of March and early April 2021 inside the oak tree with several females. In contrast, juvenile AKV spent only four days inside the tree, in mid-April after the major mating period, apparently for shelter between foraging bouts rather than rendezvousing with potential mates. Photo credits: Roy Nagle. Photo 4. (a) Adult male spotted turtle AJW on the move following an autumn rain. This male spent two weeks inside the hollow oak tree during the latter half of March 2021, along with four females and six other males. AJW apparently has a particular affinity for female ABH, as he was captured alongside her on four different occasions entering or exiting the tree. (b) Female spotted turtle NYY, one of only four reproductive adult females in our study population. Most spotted turtle populations are small and fragmented, a primary reason the species is currently under review by the U.S. Fish and Wildlife Service for federal listing under the Endangered Species Act. Photo credits: Travis Russell. Photo 5. One-year-old spotted turtle captured in a flooded meadow in June. Substantial new growth is indicated by light coloration between scutes. Like many long-lived turtles, spotted turtle populations are characterized by low fecundity and low recruitment of juveniles, which contrasts with high adult survivorship required for stable populations. Photo credit: Roy Nagle. These photographs illustrate turtles from the article, “Sheltering oak: spotted turtles in a tree” by Roy D. Nagle, Travis J. Russell, and Ryan J. Rimple published in Ecology. http://doi.org/10.1002/ecy.3585.

Impacts of oak-focused silvicultural treatments on the regeneration layer nine years posttreatment in a productive mixed-oak southern Appalachian forest

Oaks (Quercus spp.) are foundational species in forests and woodlands in the eastern USA. An oak regeneration bottleneck has occurred throughout its range in recent decades, and refining silvicultural treatments to localized conditions has become a focus in addressing this problem. This study was developed to determine species regeneration dynamics among oak and oak competitors on productive sites in response to silvicultural treatments in oak-dominated southern Appalachian mountain forests. The treatments were: an oak shelterwood treatment (25–30% basal area [BA]) reduction through midstory removal with herbicides); a prescribed fire treatment (two, late-dormant season prescribed fires occurring over a 9-yr period); a shelterwood and burn treatment (one, late-dormant season prescribed fire 3–5 yr following 30–40% BA removal); and an unmanaged control. To determine treatment impacts on the regeneration layer, changes in relative and absolute importance values and stems ha-1 (germinants up to stems ≤ 4.9 cm diameter at breast height [DBH]) were calculated at the species group and individual species level 0 and 9 yr postinitial treatment. The greatest relative increases in importance values were 1,401% and 2,995% for the red oak group and yellow-poplar (Liriodendron tulipifera), respectively, in the shelterwood and burn (SWB). Changes in all species groups were predominantly influenced by the smallest size-class (< 0.6 m tall), with the exception of northern red oak (Q. rubra) and yellow-poplar in the SWB. The SWB significantly reduced importance values of all shade-tolerant species groups and was the only treatment to decrease red maple (Acer rubrum) importance value and density over the study duration. The prescribed fire (RXF) treatment increased the red oak group importance value, while simultaneously decreasing yellow-poplar's importance value and increasing red maple's importance value. Changes in the red oak group in the SWB and the RXF were driven by northern red oak. Treatments did not significantly change the importance value of the white oak group. The SWB was the only treatment to significantly decrease overstory BA. The RXF and SWB treatments improved the competitive status of only some oak species, but modifications to these treatments might result in better control of yellow-poplar and red maple competition, further improving oak's competitive status. Although the SWB resulted in modest recruitment of northern red oak saplings, all treatments appear in need of additional follow-up vegetation control to further improve the competitiveness and recruitment of oak into large size-classes.

Cryptic Methane-Cycling by Methanogens During Multi-Year Incubation of Estuarine Sediment

As marine sediments are buried, microbial communities transition from sulfate-reduction to methane-production after sulfate is depleted. When this biogenic methane diffuses into the overlying sulfate-rich sediments, it forms a sulfate-methane transition zone (SMTZ) because sulfate reducers deplete hydrogen concentrations and make hydrogenotrophic methanogenesis exergonic in the reverse direction, a process called the anaerobic oxidation of methane (AOM). Microbial participation in these processes is often inferred from geochemistry, genes, and gene expression changes with sediment depth, using sedimentation rates to convert depth to time. Less is known about how natural sediments transition through these geochemical states transition in real-time. We examined 16S rRNA gene amplicon libraries and metatranscriptomes in microcosms of anoxic sediment from the White Oak River estuary, NC, with three destructively sampled replicates with methane added (586-day incubations) and three re-sampled un-amended replicates (895-day incubations). Sulfate dropped to a low value (∼0.3 mM) on similar days for both experiments (312 and 320 days, respectively), followed by a peak in hydrogen, intermittent increases in methane-cycling archaea starting on days 375 and 362 (mostly Methanolinea spp. and Methanosaeta spp., and Methanococcoides sp. ANME-3), and a methane peak 1 month later. However, methane δ13C values only show net methanogenesis 6 months after methane-cycling archaea increase and 4 months after the methane peak, when sulfate is consistently below 0.1 mM and hydrogen increases to a stable 0.61 ± 0.13 nM (days 553–586, n = 9). Sulfate-reducing bacteria (mostly Desulfatiglans spp. and Desulfosarcina sp. SEEP-SRB1) increase in relative abundance only during this period of net methane production, suggesting syntrophy with methanogens in the absence of sulfate. The transition from sulfate reduction to methane production in marine sediments occurs through a prolonged period of methane-cycling by methanogens at low sulfate concentrations, and steady growth of sulfate reducers along with methanogens after sulfate is depleted.

Feasibility of Systemically Applied dsRNAs for Pest-Specific RNAi-Induced Gene Silencing in White Oak

The efficacy of double-stranded RNA (dsRNA) in inducing host specific gene knockdown and mortality has been demonstrated in a multitude of insects and dsRNAs are being integrated for pest suppression in a variety of agricultural and horticultural crops. However, less attention has been applied to their use in forest settings, despite the demonstrated susceptibility of multiple forest pests to RNAi. Prior to implementation for forest pest suppression, characterization of the specificity, efficacy, and behavior of dsRNAs in the environment is essential. Therefore, we investigated the translocation and retention of exogenously applied dsRNA in an economically and ecologically significant hardwood tree when applied hydroponically. White oak (Quercus alba, L.) seedlings were exposed to dsRNAs as a root soak, and at 1, 3, 5, and 7 days post-exposure were destructively sampled, divided into stem and leaf tissue, and the RNA extracted. Gel electrophoresis was used to visualize the presence of exogenous dsRNA in treated seedling material and Sanger sequencing was used to further verify recovery of treatment dsRNAs. Both techniques confirmed the presence of the exogenously applied dsRNAs in each tissue type at each sample interval, demonstrating successful uptake and translocation of dsRNAs through white oak tissues. Our findings support root uptake as a viable delivery method for dsRNAs in hardwood seedlings, which could provide single tree protection from selected tree feeding pests or pathogens.

Mesophication of upland oak forests: Implications of species-specific differences in leaf litter decomposition rates and fuelbed composition

Without periodic fire, historically open-canopied, oak-dominated upland woodlands of the central and eastern United States are shifting to closed-canopied forests with increased abundance of shade-tolerant and typically fire-sensitive species. Once established, these encroaching species (i.e., mesophytes) are hypothesized to initiate a positive feedback termed mesophication where mesophytes perpetuate conditions that foster their own proliferation at the expense of oaks (Quercus spp.). One potential mechanism of mesophication is reduced fuel loads through faster decomposition rates of mesophyte leaf litter, as leaf litter is the primary fuel in closed canopy forests. To better understand how different tree species impact fuel loads, we compared initial leaf litter chemistry and one-year (2016–2017) decomposition rates of four non-oak species exhibiting increased abundance in the region and/or relatively high sapling/midstory abundance relative to the overstory on our sites (red maple [Acer rubrum], sugar maple [A. saccharum], American beech [Fagus grandifolia], and hickory [Carya spp.]) and three oak species (black oak [Q. velutina], chestnut oak [Q. montana], white oak [Q. alba]) in an upland oak forest in north-central Kentucky. We also evaluated fuelbed mass, composition, and bulk density beneath overstory (20–60 cm DBH) individuals of each species following leaf fall in December 2016. Except for American beech (66% mass remaining), we found non-oak leaf litter, especially that of red and sugar maple, decomposed the fastest (45 and 48% mass remaining), and oak leaf litter decomposed the slowest (54–64% mass remaining). Further, although total leaf litter fuel loads in December were similar beneath individuals of different tree species, fuel composition differed. Under non-oak crowns, the proportion of leaf litter from non-oaks was 22–35%, while under oak crowns, the proportion of leaf litter from non-oaks was only 10–12%. This suggests that individual trees of non-oaks are impacting fuel composition beneath their own crowns despite continued oak dominance at the stand scale. Considering differences between species in both leaf litter inputs based on allometric equations and decomposition rates, modeled leaf litter fuel loads in a forest composed entirely of red maple, sugar maple, or Carya spp. were ∼20% lower than an oak forest after one year of decomposition. While limited to the species examined in this study, these findings confirm that the leaf litter of non-oaks, excluding American beech, decomposes more rapidly than oak and that individual non-oak trees alter fuelbed composition beneath their crowns, suggesting that oak woodlands will become less-flammable with increasing mesophytic dominance.

Preferences of avian seed-hoarders in advance of potential American chestnut reintroduction

Nut-bearing trees such as oaks (Quercus genus) and American chestnut (Castanea dentata, hereafter: chestnut) rely on scatter-hoarding animals for seed dispersal. With the pursuit of blight-resistant chestnuts for eventual reintroduction into eastern hardwood forests of the United States, it becomes important to understand how foraging preferences of avian seed-hoarders will influence chestnut dispersal in oak-dominated forests. Using six seed selection trials over three years and two “seasons” (early fall and late fall), we assess the relative seed preferences – when gathering seeds for hoarding or consumption – of five species of avian seed dispersers in southeast Ohio. In each trial, we presented an equal number of chestnuts and two species of common acorns, black (Q. velutina) and white oak (Q. alba), to wild birds on feeding platforms monitored by cameras. We used Bayesian discrete choice models to determine preferences of each species, and estimate the influence of natural variation in background mast availability (i.e., different years and seasons). Blue Jays (Cyanocitta cristata) showed a consistent preference for the seeds of black oak over chestnut over white oak, and the strength of preference for black oak increased in late season when acorns were scarce. Other species showed variable preferences, with White-breasted Nuthatch (Sitta carolinensis) the only species to prefer chestnuts over both acorns, though sample size was small (n = 26 selections). Our results suggest chestnuts are used by a host of avian seed-hoarders that may facilitate dispersal of chestnut, particularly in years of black oak mast failure.

Phylogenomic analyses highlight innovation and introgression in the continental radiations of Fagaceae across the Northern Hemisphere

Northern Hemisphere forests changed drastically in the early Eocene with the diversification of the oak family (Fagaceae). Cooling climates over the next 20 million years fostered the spread of temperate biomes that became increasingly dominated by oaks and their chestnut relatives. Here we use phylogenomic analyses of nuclear and plastid genomes to investigate the timing and pattern of major macroevolutionary events and ancient genome-wide signatures of hybridization across Fagaceae. Innovation related to seed dispersal is implicated in triggering waves of continental radiations beginning with the rapid diversification of major lineages and resulting in unparalleled transformation of forest dynamics within 15 million years following the K-Pg extinction. We detect introgression at multiple time scales, including ancient events predating the origination of genus-level diversity. As oak lineages moved into newly available temperate habitats in the early Miocene, secondary contact between previously isolated species occurred. This resulted in adaptive introgression, which may have further amplified the diversification of white oaks across Eurasia.

Canopy spectral reflectance detects oak wilt at the landscape scale using phylogenetic discrimination

The oak wilt disease caused by the invasive fungal pathogen Bretziella fagacearum is one of the greatest threats to oak-dominated forests across the Eastern United States. Accurate detection and monitoring over large areas are necessary for management activities to effectively mitigate and prevent the spread of oak wilt. Canopy spectral reflectance contains both phylogenetic and physiological information across the visible near-infrared (VNIR) and short-wave infrared (SWIR) ranges that can be used to identify diseased red oaks. We develop partial least square discriminant analysis (PLS-DA) models using airborne hyperspectral reflectance to detect diseased canopies and assess the importance of VNIR, SWIR, phylogeny, and physiology for oak wilt detection. We achieve high accuracy through a three-step phylogenetic process in which we first distinguish oaks from other species (90% accuracy), then red oaks from white oaks (Quercus macrocarpa) (93% accuracy), and, lastly, infected from non-infected trees (80% accuracy). Including SWIR wavelengths increased model accuracy by ca. 20% relative to models based on VIS-NIR wavelengths alone; using a phylogenetic approach also increased model accuracy by ca. 20% over a single-step classification. SWIR wavelengths include spectral information important in differentiating red oaks from other species and in distinguishing diseased red oaks from healthy red oaks. We determined the most important wavelengths to identify oak species, red oaks, and diseased red oaks. We also demonstrated that several multispectral indices associated with physiological decline can detect differences between healthy and diseased trees. The wavelengths in these indices also tended to be among the most important wavelengths for disease detection within PLS-DA models, indicating a convergence of the methods. Indices were most significant for detecting oak wilt during late August, especially those associated with canopy photosynthetic activity and water status. Our study suggests that coupling phylogenetics, physiology, and canopy spectral reflectance provides an interdisciplinary and comprehensive approach that enables detection of forest diseases at large scales. These results have potential for direct application by forest managers for detection to initiate actions to mitigate the disease and prevent pathogen spread.

Effects of soil treatments and tree species on reforestation of well pads

Anthropogenically induced arrested succession is a global problem in forest ecosystems. In northern Michigan (U.S.A.), oil development has arrested succession in forest landscapes since the 1970s and oil well pads have not reforested up to 30 years after being vacated. To explore pathways for reforestation, we evaluated survivorship and growth of northern red oak (Quercus rubra), white oak (Q. alba), jack pine (Pinus banksiana), and red pine (P. resinosa) at monthly intervals during growing seasons from 2015 to 2019 on pads, which had been vacated 9–34 years prior to the initiation of our study. We planted trees in four soil surface treatments—experimental control (planting only, no treatment), disking, fertilization, and disking with fertilization. While monitoring survivorship and growth of planted trees, we concurrently examined natural reforestation in untreated control areas on each pad and differences between soil characteristics of pads and surrounding forests. Pinus resinosa displayed highest overall survivorship regardless of treatment, but maximum survivorship in disked soils and experimental control areas. Other species had highest survivorship in disked soils. There was no significant reforestation in untreated control areas during the 5‐year study period. Pads had higher levels of Bray P, Ca, and Mg, but lower levels of Fe, organic matter, and moisture than forest soils. Concentrations of toxic chemicals associated with drilling activities were not different between pad and forest soils or, if different, within acceptable levels for plant growth. In reforesting well pads, restorationists should plant P. resinosa in disked soil to achieve highest tree survivorship and density.

Even more oak species in Mexico? Genetic structure and morphological differentiation support the presence of at least two specific entities within Quercus laeta

AbstractDifferentiation among populations, sometimes despite ongoing gene exchange, is a key step in speciation. Therefore, comparison of intra‐ and interspecific differentiation patterns is of great significance to understanding speciation. The genus Quercus is an interesting system to test speciation models in the presence of gene flow, due to its weak interspecific reproductive barriers. The aim of the present study was to characterize the degree and pattern of morphological and genetic differentiation among different morphotypes in the white oak Quercus laeta, some corresponding to the previously described species Quercus centralis, Q. laeta, Quercus prinopsis, and Quercus transmontana, as well as geographically structured variation within Q. transmontana not described previously. Our goal was to evaluate if some of these can be considered distinct specific entities or are rather part of a continuum of variation. Nine microsatellite loci and two intergenic regions of chloroplast DNA were analyzed. Morphological differences were evaluated using geometric morphometrics. Chloroplast DNA showed low differentiation, suggesting introgression or sharing of ancestral haplotypes among the Q. laeta morphotypes. Nuclear microsatellites indicated differentiation into two distinct main genetic groups, which were congruent with morphological differentiation. In conclusion, nuclear markers and morphological variations suggest the existence of at least two different entities within Q. laeta.

Echoes, and: Mist

Echoes, and: Mist Romeo Oriogun (bio) Echoes In Boston, I walked the night.From blackness I beheld the salvationof dreams. I have moved. In rural Oregon, the plants spoke.Red Alders, White Oaks stood still,two geldings ran aroundin a small enclosure. Tiny creatures ran underneathmy foot as I walked the wooden bridgethat separated small pondfrom paths leading to a farmhouse. So much hope ran through this familiarspace. Across the bridge, in the small pond,I saw the algae of my childhood. I trembled,I fell to the ground, it was August. I heard the earthworms saying,we are of this world,this world is ours only,our great bounty, in it you live. In all your yearning for home,you can only tread this pondfrom here to there, the beginningof a narrowing path. [End Page 44] Mist I entered a train stationand the air trembled, swallows searchedfor rooms in the brief wonder of flight. The graffiti on the pillars spoke of nothing.The day ran into the nightlike a child who having been harmedby a stranger must seek refugein the darkness of a closed room. I wanted the world to be still, the cloudsshaped like bicycles to stop moving.I wanted the girl, whose black clothes spokeof mourning, to look at me. The world has happened, I had left home,and from afar I could imagine the houseson the hill of my birth, the houses leaninginto each other like old souls fallinginto the slow embrace of pity. The doors to my country have been closedto me, the canvas of my mind torn into shreds.What home I knew is now the abode of hawks,and the falconer whose falcon escapedinto the wild must begin to think about freedom. In every mirror, I said to myself, I did not dietoday; the world kept moving. At my departure I said goodbye, I said welcome,I said nothing, and the city turned its back at me, [End Page 45] becoming a stranger I will walk past someday,in a country beyond rivers, then turnto wonder, where have I seen this face, this kingdom,where was my life taken from me? [End Page 46] Romeo Oriogun Romeo Oriogun is the author of Sacrament of Bodies, a finalist for the Lambda Award for Gay Poetry. He has received fellowships and support from Ebedi International Writers Residency, Harvard University, Hutchins Center for African and African American Research, Oregon Institute for Creative Research, and the IIE Artist Protection Fund. Winner of the 2017 Brunel International African Poetry Prize and an alumnus of the Iowa Writers' Workshop, he currently lives in Ames where he is a Postdoctoral Research Associate at Iowa State University. Copyright © 2022 University of Nebraska Press

The Good Fortune of Minerva Green

The Good Fortune of Minerva Green Anjanette Delgado (bio) who is not desperate at sunset?dawn is so much easier than dusk. andrei codrescu, from the poem, "moving on we all must" If there was one thing Minerva Green had always believed, it was that one made one's own good fortune. It was something her mother had repeated often as she grew up, and nothing had given her a reason to doubt it until, newly married and secretly pregnant, they decided to use Eli's army veteran's voucher to buy a house nearer to his mechanical engineering job in Holmes County, Florida. The new house was hours from home, in a brand-new subdivision called Meadows of White Oak, and she'd known it from the day they moved in. That she'd really gone and done it now. That "one makes one's own good fortune" was only true some of the time. That sometimes places and people could change things. Could change you. It was while sitting with Eli on the hood of their maroon Pontiac, waiting for a moving truck that was hopelessly lost, that Minerva had decided to replace her good fortune belief with a new one: there is nothing more terrifying than dusk in the suburbs. Minerva had known it then and known it since, and nobody was going to change her mind now. All that suburban sameness? Everything and everyone hypnotized to be a certain way, like a cult? And what about the way dusk turned into darkness there the minute all that sameness could have begun to feel comforting instead of stifling? Wasn't that just petty? You'd better believe she'd wanted to move back. For years, she'd railed against all of it: the middle class she didn't believe really existed, the subdivisions, the dusk, routine and its moron cousin, tedium. But no one [End Page 110] listened, or maybe it was just Eli who didn't, and now, of course, after all these years, her illness was back. What a joke. That it was back so much stronger, like a younger version of itself, despite the surgery, the boring poison sessions, and the intricate jigsaw puzzles Dr. Taylor referred to as her "customized meds combo." Minerva knew a raw deal when she saw one and, for this one, she blamed dusk. It was so clear to her now: how that rat of darkness and its daily preview had played a role in all of it. It's true she'd been a rebel. Wearing her orange miniskirt to protest with the older, married women at the mall. Eloping with Eli the year before graduating from college. Taking up smoking the moment they left the neighborhood. Two packs a week for thirty-four years even though Eli thought they had agreed: one a day, max. Instead, out she'd walk at the first sign of sundown, a single cigarette balanced between her right hand's middle and index fingers, her left hand curled around the tinfoil origami holding the others. In her pocket: two breath mints, a neon-colored drugstore lighter, and a ziplock sandwich bag for catching ashes and quickly hiding them along with forbidden butts, should Eli come home early. Back then, she thought she walked and smoked to relax from the uneasiness of not belonging. Her restlessness and desire to contribute something more, she channeled into pacing her front lawn, breathing in the sweet smoke, allowing every cigarette to merge into a single one in her head, watching the sun take its time calling it a day, life around her turning into black dust. Eli didn't see the big deal. He'd taken to the new neighborhood quickly, and Minerva wondered if he really didn't notice what was so obvious to her: people in Meadows of White Oak were simply not used to seeing this much color so close to their homes. Not that anybody was openly mean. But Minerva felt it. Sometimes in the wives, walking their dogs around the block one last time before supper, returning her wave-and-a-smile with the strangest expressions on their faces, something between...