Red Cedar Research Articles

Linking microbial communities, functional genes and nitrogen-cycling processes in forest floors under four tree species

Tree species can influence rates of soil N transformations, but the question remains whether differences in N cycling rates are mirrored by the abundance of relevant functional genes. We studied whether the influence of tree species on soil N transformation processes and abundance of functional genes exist across two sites in British Columbia with different N availability. We used the 15N pool-dilution method to estimate gross rates of ammonification and nitrification in forest floors of four conifers in a common garden experiment. The abundances of bacteria, fungi, nitrification (AOA amoA, AOB amoA) and denitrification (nirS, nirK) genes were determined by qPCR. Western red cedar (Thuja plicata) had the highest rates of gross ammonification and NH4+ consumption, followed by Sitka spruce (Picea sitchensis), hemlock (Tsuga heterophylla), and Douglas-fir (Pseudotsuga menziesii); all species showed net nitrate immobilization. Western red cedar forest floors had the greatest abundance of bacterial 16S genes and ammonia-oxidizing archaea amoA genes. This suggests that tree species foster different abundances of ammonification and denitrification functional groups. Differences in N transformation rates between the sites were related to site N status, as reflected in C:N ratios of the forest floor and microbial biomass, and were more closely tied to rates of N consumption rather than gross mineralization. Rates of most N transformation processes were related to microbial C:N ratio, indicating that the N status of microbes rather than their biomass or activity level determined the rates of N cycling. Ammonification rates were associated with forest floor and microbial biomass C:N ratio as well as bacterial and fungal abundances. Nitrification rates and denitrification gene abundance were associated with microbial biomass C:N ratios and AOA amoA gene abundance. The forest floor's genetic potential for denitrification was positively correlated with its nitrification potential as indicated by ammonia-oxidizer abundance. We conclude that tree species influenced forest floor N cycling and soil microbial gene abundances, and that functional genetics can be useful for exploring mechanistic links between tree species and nitrogen cycling processes.

Hawksworthiomyces gen. nov. (Ophiostomatales), illustrates the urgency for a decision on how to name novel taxa known only from environmental nucleic acid sequences (ENAS)

There have been many recent studies using environmental nucleic acid sequences (ENAS) to assess fungal diversity. As a result, more than a third of all fungal sequences in GenBank are of environmental origin. But inconsistent annotation of the thousands of undescribed taxa represented by these sequences limits access to these data. Consequently, these ENAS and the taxa they represent are rarely considered in other studies, and especially not in taxonomic treatments. This problem is confounded by the fact that the current version of the International Code of Nomenclature for Algae, Fungi, and Plants (Melbourne Code) prohibits the description of novel taxa known only from ENAS. There have been suggestions to emend the Code to allow a systematic nomenclatural treatment of these currently ‘orphan’ taxa but this has yet to occur. In this study, we considered the feasibility of using sequences from environmental studies to resolve the generic status of Sporothrix lignivora. This species forms a single lineage distinct from Sporothrix and other genera in the Ophiostomatales. BLAST searches in GenBank using LSU and ITS sequences of S. lignivora corresponded with several sequences from environmental studies. This also led to the discovery of isolates collected in diversity studies based on culturable fungi, with high similarity to S. lignivora. Phylogenetic analyses including taxa representing all major genera and lineages in the Ophiostomatales revealed a distinct, well-supported lineage that included S. lignivora and the ENAS. This confirmed the presence of a new genus in the Ophiostomatales described here as Hawksworthiomyces gen. nov., with S. lignivora as type species. Whereas only one described species was known in the so-called S. lignivora complex, our analyses revealed nine additional lineages in what is now Hawksworthiomyces. For three of these lineages, we were able to obtain isolates and these are described as Hawksworthiomyces taylorii sp. nov., Hawksworthiomyces crousii sp. nov., and Hawksworthiomyces hibbettii sp. nov. Five of the lineages each included one or more sequences from single studies, and thus remain unnamed. The remaining lineage included two sequences from separate studies of fungi inhabiting conifer wood. One of these sequences was an uncultured fungus clone from a spruce log in Sweden. The other sequence was for an isolate from a western red cedar fencepole in British Columbia, Canada, that was subsequently lost. These two ITS sequences differ in only two nucleotide positions. We are confident that they represent the same taxon and meet the criteria for an ENAS species, for which we provide the name, Hawksworthiomyces sequentia sp. nov. ENAS, and designate a DNA sequence as type in the absence of a type specimen. This case study makes it clear that environmental sequences and those from lost isolates can be extremely valuable in phylogeny-based taxonomic studies. It emphasises the fact that the Code should be emended to enable the naming of such taxa in a manner that will facilitate their incorporation in other studies.

Inhibition of basidiospore germination by western redcedar heartwood extractives

Understanding the relationship between extractives and decay resistance in western red cedar (WRC) is essential for breeding durable planting stock. To date, most such work has focused on resistance to mycelial attack. However, this is potentially misleading since WRC is largely used in above-ground applications where basidiospore germination is the primary way in which the wood is initially colonized. Efficacy against basidiospores is likely a critical factor affecting wood’s decay resistance in above-ground applications. In this study the effect of selected extractives on basidiospore germination was evaluated. Partially-extracted WRC veneer samples, and spruce samples treated with beta-thujaplicin, thujic acid, or plicatic acid were used. Beta-thujaplicin and thujic acid were associated with significantly reduced rates of Gloeophyllum sepiarium, Fomitopsis palustris, and Dichomitus squalens basidiospore germination. Plicatic acid was not associated with any effect on basidiospore germination. Planting stock that generates heartwood with high concentrations of thujaplicins and thujic acid should be selected to yield wood that will be resistant to basidiospore germination.

Macrolichen diversity as an indicator of stand age and ecosystem resilience along a precipitation gradient in humid forests of inland British Columbia, Canada

The distributional ecology of 87 macrolichens is reported from 14 unmanaged mid-seral and old forest stands along a precipitation gradient in south-central British Columbia. We used a combination of univariate and multivariate statistics to investigate the role of forest structure and stand age in the distribution of epiphytic macrolichens in interior cedar-hemlock forests. Old forests support a higher number of species; although mean species richness is not significantly different between the two age classes. Terricolous and epixylic community structure is correlated with stand age and log characteristics, but the epiphtytic community is not. Epiphytic community structure is strongly associated with precipitation in the old stands, but not in the mid-seral stands. Old forests at the wetter end of the precipitation gradient contained several old-growth associated species, all of which are hygrophytic. Most epiphytic macrolichens associated with old forests are not dependent on specific structural attributes. However, western red cedar (Thuja plicata Donn ex D. Don) harbors the greatest number of arboreal macrolichen species by far in these unmanaged stands and should, therefore, be considered a key indicator in managed forests. Our study suggests that most macrolichen species found in old forests can also occur in 70- to 165-year-old forests dating from stand-replacing fires. Old forests, however, clearly provide important habitat for oceanic epiphytes at the edge of their ecological range in the interior of British Columbia. Our findings illustrate that the macrolichen flora in wet toe-slope stands in humid inland British Columbia has a high level of resilience following disturbance under natural succession conditions. It also underlines the point that some species, like Lobaria pulmonaria, are good indicators of old-growth forests in certain regions but not in others, suggesting a careful use of the term old-growth dependence.

Effects of Woody Mulches and Dimethenamid-P on Container Grown Ligustrum japonicum and Viburnum macrocephalum

Current weed control practices in nursery container plant production consist primarily of hand weeding and application of preemergence herbicides. Non-chemical weed control methods, such as mulches, could reduce herbicide use, reduce potential environmental concerns from offsite herbicide movement, and decrease the expense of weed control. Before implementation, alternative methods of weed control must be evaluated for effects on the growth of common container-grown species. Mulches made from readily available tree species, including eastern red cedar (Juniperus virginiana), ground whole loblolly pine (Pinus taeda), Chinese privet (Ligustrum sinense), and sweetgum (Liquidambar styraciflua), were evaluated at multiple depths with and without the herbicide dimethenamid-P (Tower®). Wax-leaf ligustrum (Ligustrum japonicum) and snowball viburnum (Viburnum macrocephalum) treated with dimethenamid-P, averaged over mulch treatments, had up to 7% less growth compared to non-herbicide treated plants, but marketability was not affected. Mulch species and depth had no effect on plant growth. Results indicate that these readily available mulch species can be applied at depths up to 10.2 cm (4 in) for weed control in container plant production.

Review: British Columbia's Inland Rainforest: Ecology, Conservation, and Management

Stevenson, Susan K., Armleder, Harold M., Arsenauly, Andre, Coxson, Darwyn, Delong, S. Craig and Jull, Michael. British Columbia's Inland Rainforest: Ecology, Conservation, and Management. Vancouver, Canada: University of British Columbia Press, 2011. 456 pp. ISBN: 9780774818506, paperback. US$ 41.95, illustrated. Also available in hardcover format ISBN 9780774818490.A fact-filled and extremely useful offering from silvicultural and ecosystem professionals, biologists, ecologists, systems scientists and others, British Columbia's Inland Rainforest provides a snapshot, a look at the present conditions of this unique ecosystem in light of past and future management choices. Included are 128 figures, color plates and illustrations, 20 tables, three appendices, a species index, glossary and various exposes that highlight features of the text, which itself includes more than 50 sections detailing everything from carbon stocks to soil horizons to forest edge effects on plant and animal life to native medicine and many others. The book grew from a project with scientific goals-to supplement a government forestry report with data so that managers and other stakeholders could make well-informed choices. The authors made a wonderful choice to expand their scope and offer the work to the public.British Columbia's inland rainforest is unique. There is no other place on the planet where a temperate rainforest exists so far from the coast, with much of its biome determined by continental rather than coastal geography. For example, many of the species in the inland rainforest migrated from elsewhere in continental North America during the end of the last glaciation, or from the coast via specific vectors. They continue to survive in a setting that includes thousand-year-old red cedar trees and lichen species (e.g. cyanolichen) that are not found elsewhere or nowhere else in such great diversity and abundance. Snowmelt during the summer promotes groundwater abundance and a humidity level unrivaled in a continental forest setting.Here, ancient red cedar and western hemlock make unique rotted-out settings for fungus, bryophyte, lichen, vascular plants, invertebrates and vertebrate animals, dens in hollowed out trees for martens and black bears. Yet in human terms, the same trees providing the substrate for such a rich ecology have also driven management choices that have led to their destruction.Historically, such immense trees with internal voids are called decadent and forest management has opted to harvest these old landscapes to allow planting of young plantation stands that replace them, often with changes to species for a standardized harvest regime. Ironically, the work is done in winter when the marshy rainforest soil has frozen and ice roads or other means of transport can be constructed. …

110 Use of fecal NIRS to predict red cedar intake by goats

110 Use of fecal NIRS to predict red cedar intake by goats

Project Artifacts: Through the Banks of the Red Cedar

Project Artifacts:Through the Banks of the Red Cedar Maya Washington (bio) A documentary film abc World News Tonight. August 3, 2011 Diane Sawyer: We have a passing to note tonight.A star of sports and later the movies: Bubba Smith,born Charles Aaron Smith in Beaumont, Texas. The 6’7”defensive standout for the Raiders, Oilers, and Colts.He went on to act in the Police Academy movies.Bubba Smith was 66. Los Angeles, CA – August 2011 You ever thought about how your body fits in the worldHow big fits with small and vice versaHow I’m a giant but I can’t go in that storeHow I left the Golden Triangle with change in my pocketHow I returned in a white RivieraHow I affixed five gold decals on the door to spell my name like an address I’ve got all the riches, baby, one man can claim You ever thought about how a body fits in the worldHow every article starts out saying I’m 6’7” and 290 poundsWhat I hear when a stadium full of white folks chants “Kill, Bubba, Kill”How being this big this black and this fast feels on game day [End Page 133] What it’s like to fall for a Lansing girl and take her to a movieHow easily I settle into darkness when her arm rests against mineHow cramped it all feels when the lights come onWhat it’s like not to hold her hand as we walk home I’ve got all the riches, baby, one man can claim Think about how a body fits in a worldHow a heart breaks like a record or a boneWhat it’s like to be the number one pickHow people only remember a white RivieraWhat I weighedHow tall I stood I’ve got all the riches, baby, one man can claim Washington, DC – August 1963 Nineteen sixty-three is not an end, but a beginning. Andthose who hope that the Negro needed to blow off steamand will now be content will have a rude awakening if thenation returns to business as usual. —Martin Luther King, Jr. Baldwin Hills, CA – August 2011 I don’t know how many times I’ve cut through Baldwin Hills to get to’sc from Inglewood or Culver City over the years. I could have beenwalking through the Target parking lot on La Cienega as he passed inhis car on the way home from the gym. It’s been a week since he died—the news teams and their live shots are no longer on the front lawn.There’s a quaint little potluck spread of fruit, crackers, cheese, andmeats on the dining room table. My dad and his teammates tell stories.The den reminds me of my dad’s trophy room and the ’80s. I sit onBubba’s enormous sofa as if I’m Lily Tomlin. As if I’m the little girlstanding next to him while he signs autographs at msu homecoming [End Page 134] back when he was Police Academy famous and I heard On the Banks ofthe Red Cedar for the first time. He was my first real-life movie star. Theonly man I’ve ever met that was bigger than my dad. Who I realize, inthis moment, was once 19, had friends, and a life, long before I wasborn. He’s been fielding calls from reporters on his flip phone the wholetrip. Details about how they played against each other as teenagers inan all-black league. I wonder what would have happened if Bubba andhis dad hadn’t spoken up when Duffy asked if there were any otherblack boys they should take a look at. I wonder how many heavilyrecruited kids today would go out of their way to tell a Division I schoolabout an opponent 80 miles away. Most of my life, I believed magicalwhite men came down to Texas, plucked my dad out of Jim Crow, andgave him a scholarship to msu. He played for...

Effects of natural and anthropogenic environmental influences on tree community composition and structure in forests along an urban-wildland gradient in southwestern Ohio

Unprecedented population growth and urban expansion are rapidly transforming natural and agricultural settings into highly modified urban and suburban landscapes in developed areas worldwide. A myriad of anthropogenic environmental disturbances invariably accompany such dramatic shifts in land use, and disentangling the effects of these multiple stresses on ecosystem variation pose major challenges as the world’s urban population continues to increase. Here, we quantitatively characterized environmentally-mediated variation in tree-community composition along an Urban-Wildland gradient in southwestern Ohio, using tree censuses conducted in sample plots at six study sites categorized as Urban, Exurban, or Wildland based on analyses of a broad suite of natural and anthropogenic environmental variables. Several direct measures of the tree-census data, including species richness, abundance, diversity metrics, and evenness, exhibited significant increases from Urban to Wildland sites. Non-Metric Multidimensional Scaling (NMDS) showed that tree composition within study plots also varied systematically along the gradient, with significant differences among sites captured primarily on NMDS Axis 1. The dominant tree species at Urban and Exurban sites was Acer saccharum (sugar maple). While this species was also abundant at Wildland sites, two other species, Asimina triloba (paw paw) and Juniperus virginiana (red cedar) tended to be more abundant. Regression-tree analyses demonstrated that tree-community composition was controlled by a complex combination of natural and anthropogenic factors, with primary roles for population density and other indicators of urbanization at broader and intermediate scales; natural factors, such as aspect, soil drainage, elevation, slope, and soil pH were important in differentiating among Urban, Exurban, and Wildland sites already primarily categorized by anthropogenic agents.

植物空间分布格局中邻体距离的概率分布模型及参数估计

PDF HTML阅读 XML下载 导出引用 引用提醒 植物空间分布格局中邻体距离的概率分布模型及参数估计 DOI: 10.5846/stxb201412182517 作者: 作者单位: 中国科学院烟台海岸带研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31000197，31570423）；中国科学院知识创新工程项目（KZCX2-EW-QN209） Nearest neighbor distance in spatial point patterns of plant species-probability distribution model and parameter estimation Author: Affiliation: Yantai Institute of Coastal Zone Research, CAS Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:最近邻体法是一类有效的植物空间分布格局分析方法，邻体距离的概率分布模型用于描述邻体距离的统计特征，属于常用的最近邻体法之一。然而，聚集分布格局中邻体距离（个体到个体）的概率分布模型表达式复杂，参数估计的计算量大。根据该模型期望和方差的特性，提出了一种简化的参数估计方法，并利用遗传算法来实现参数优化，结果表明遗传算法可以有效地估计的该模型的两个参数。同时，利用该模型拟合了加拿大南温哥华岛3个寒温带树种的空间分布数据，结果显示：该概率分布模型可以很好地拟合美国花旗松（P. menziesii）和西部铁杉（T. heterophylla）的邻体距离分布，但由于西北红柏（T. plicata）存在高度聚集的团簇分布，拟合结果不理想；美国花旗松在样地中近似随机分布，空间聚集参数对空间尺度的依赖性不强，但西北红柏和西部铁杉空间聚集参数具有尺度依赖性，随邻体距离阶数增加而变大。最后，讨论了该模型以及参数估计方法的优势和限制。 Abstract:In ecology, the spatial point pattern, which is obtained by mapping the locations of each individual as points in space, is a very important tool for describing the spatial distribution of species. There are three generally accepted types of spatial point patterns:regular, random, and aggregated. To detect spatial patterns, quadrat sampling is commonly applied, where quadrats are randomly thrown on the space and then the number of individuals in quadrats is used to fit Poisson model or NBD model, respectively. Distance sampling is an alternative method for spatial point pattern analysis, which is flexible and efficient, especially in highly dense plant communities, and in difficult terrain. Nearest neighbor method is one effective distance sampling method in spatial distribution pattern analysis. There are two kinds of nearest neighbor distances (NND):point-to-tree NND, distances from randomly selected points (sampling points) to the nearest individuals; and tree-to-tree NND, distances from selected individuals to their nearest neighbors. In this paper, we show a probability distribution model of higher order nearest neighbor distance (tree-to-tree). As we see the expression of this model is complicated; therefore, parameter estimation using conventional method is not a trivial task. In statistics, there are many numerical methods for estimating the parameters of complicated probability distribution model such as moment method, empirical method, graphical method, and maximum likelihood method. In previous literature, maximum likelihood method has been applied for parameter estimation and the optimized estimates on the log-likelihood surface were searched by Nelder-Mead algorithm. However, maximum likelihood estimation was fraught with nontrivial numerical issues when the samples of tree-to-tree distance were rare. In this paper, we use an alternative method, genetic algorithm, to estimate the two model parameters. The computation can be further simplified by defining a suitable objective function based on the expectation and variance. The probability distribution model is then used to fit spatial distribution data of three tree species on southern Vancouver Island, western coast of Canada. It is found that the proposed probability distribution model can fit nearest neighbor distance samples well for Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla). For tree species western red cedar (Thuja plicata), the fitting is not so satisfied because individuals of western red cedar are usually distributed as small clusters. As Douglas-fir is almost randomly distributed in space, the estimated parameter representing spatial aggregation nearly does not change. However, the estimated parameter increases when spatial scale increases for the other two tree species, western hemlock and western red cedar. A short discussion about the advantages and limitations of the probability model and its parameter estimation methods is also presented. Theoretically, the probability distribution model presented in this study is applicable to all kinds of spatial point patterns ranging from highly aggregated to complete random. However, as the actual point patterns of tree species usually deviate from theoretical assumptions, the probability distribution model has a few shortcomings such as scale dependence. To gain a better fitting, higher orders of nearest neighbor distances are needed. A balance between field work burden and performance of model fitting should be considered. We suggest that ideal orders of nearest neighbor distances are from 2 to 6. Another potential that can improve the fitting performance is using mixed probability distributions. 参考文献 相似文献 引证文献

Biochar amendment of grassland soil may promote woody encroachment by Eastern Red Cedar

Although carbon (C) additions to soil have been used in restoration to combat invasive species through changes in soil nitrogen (N) availability, carbon amendments to soil derived from plant material can impact soil N availability in a species-specific manner. As such, amendment-driven feedbacks on N may impact invasive species success and woody encroachment. Soil amendments like biochar, which is often added to soil to increase C storage in grassland systems, may unintentionally encourage woody encroachment into these grasslands by changing soil N dynamics. Few studies have examined biochar impacts on non-agricultural species, particularly invasive species. Woody encroachment of Eastern Red Cedar (Juniperus virginiana) into grasslands provides an ideal context for examining the impact of biochar in grasslands. In the greenhouse, we examined the effect of biochar or leaf litter derived from native and exotic grasses on J. virginiana seedling growth. Juniperus virginiana seedlings grew 40% bigger in biochar amended soil as compared to seedlings grown in litter amended soil. Additionally, we found a more than 2 order of magnitude increase in available NH4+ in the biochar treatments compared to the litter amended soils. Furthermore we found that biochar feedstock type did not have an impact on the effect of biochar, as both native and exotic grass biochar had similar impacts on soil N levels and J. virginiana growth. Our work suggests that once grassland litter is converted to biochar, species impacts on soil N may disappear. In conclusion, our data suggests soil amendments of biochar may encourage woody encroachment into grasslands.

CryJ-LAMP DNA Vaccines for Japanese Red Cedar Allergy Induce Robust Th1-Type Immune Responses in Murine Model.

Allergies caused by Japanese Red Cedar (JRC) pollen affect up to a third of Japanese people, necessitating development of an effective therapeutic. We utilized the lysosomal targeting property of lysosomal-associated membrane protein-1 (LAMP-1) to make DNA vaccines that encode LAMP-1 and the sequences of immunodominant allergen CryJ1 or CryJ2 from the JRC pollen. This novel strategy is designed to skew the CD4 T cell responses to the target allergens towards a nonallergenic Th1 response. CryJ1-LAMP and CryJ2-LAMP were administrated to BALB/c mice and antigen-specific Th1-type IgG2a and Th2-type IgG1 antibodies, as well as IgE antibodies, were assayed longitudinally. We also isolated different T cell populations from immunized mice and adoptively transferred them into naïve mice followed by CryJ1/CryJ2 protein boosts. We demonstrated that CryJ-LAMP immunized mice produce high levels of IFN-γ and anti-CryJ1 or anti-CryJ2 IgG2a antibodies and low levels of IgE antibodies, suggesting that a Th1 response was induced. In addition, we found that CD4+ T cells are the immunological effectors of DNA vaccination in this allergy model. Together, our results suggest the CryJ-LAMP Vaccine has a potential as an effective therapeutic for JRC induced allergy by skewing Th1/Th2 responses.

CRESCIMENTO, ACÚMULO DE NUTRIENTES E FENÓIS TOTAIS DE MUDAS DE CEDRO-AUSTRALIANO (<i>Toona ciliata</i>) INOCULADAS COM FUNGOS MICORRÍZICOS

http://dx.doi.org/10.5902/1980509820583O presente estudo teve por objetivo avaliar a produção de mudas de cedro-australiano quanto à capacidade de crescimento, nutrição e produção de fenóis totais inoculadas com fungos micorrízicos arbusculares (FMAs). Realizou-se experimento em casa de vegetação com três tratamentos compostos por Gigaspora margarita, Glomus clarum e Glomus etunicatum testados de forma isolada e quatro tratamentos compostos pela combinação destas espécies: Gigaspora margarita + Glomus clarum, Gigaspora margarita + Glomus etunicatum, Glomus clarum + Glomus etunicatum e Gigaspora margarita + Glomus clarum + Glomus etunicatum. Todos os tratamentos com o inóculo fúngico foram avaliados sem a adição de fósforo no substrato. Em comparação, foram utilizadas três testemunhas (sem fungo) contendo três doses de fósforo: 0, 50 e 100 mg dm-3, totalizando dez tratamentos. O delineamento experimental foi em blocos casualizados, com cinco repetições. Após 140 dias de germinação, foi observado que todas as espécies de FMAs inoculadas de forma isolada ou combinada promoveram benefícios significativos no crescimento, nutrição e produção de fenóis totais nas mudas de cedro-australiano em solos contendo baixa disponibilidade de fósforo. A mistura no solo de Gigaspora margarita, Glomus clarum e Glomus etunicatum foi capaz de proporcionar incrementos significativos no desenvolvimento das plantas na maioria dos parâmetros avaliados, obtendo-se desempenhos superiores ou equivalentes às plantas testemunhas não micorrizadas e cultivadas em solos adubados com fósforo. Isto sugere que os FMAs podem promover redução na adubação fosfatada no processo de produção de mudas de cedro-australiano.

The response of light, water, and nutrient availability to pre-commercial thinning in dry inland Douglas-fir forests

Fire suppression and limited forest management have caused overstocking in many forests across the western United States. Overstocked stands have higher competition for limiting resources and causes tree stress. The amount of stress a tree experiences is related to the current availability of resources (site productivity), and the competition for those resources (stand density). Stressed trees are more susceptible to insects, disease, and mortality, which cause fuel buildup and increase wildfire risk. Pre-commercial thinning (PCT) can alleviate stress by decreasing the amount of competition in younger stands. The objective of this study was to determine how reducing competition through PCT might improve resource availability to trees at a range of initial stand conditions.We used a triplet-plot approach including 4.3m and 5.5m spacing and compared those to unthinned controls in stands varying in site productivity (height growth) and density (initial stand basal area) throughout northern Idaho and northeastern Washington. Stands were dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Douglas ex D. Don) Lindley), and western red cedar (Thuja plicata Donn ex D. Don). As expected, higher density stands intercepted greater amounts of light. Thinned stands intercepted 33–58% less light than controls, depending on tree spacing. Site productivity was positively correlated with soil moisture in the spring and soil temperature in both the spring and summer. Pre-commercial thinning increased soil moisture by 6% in the spring and 10% in the summer, and soil temperature increased by 0.5°C in spring and 1°C in summer. Douglas-fir foliar N, Ca, Zn concentration decreased after thinning, while P and B increased and S, K, and Cu were unchanged. Thinning had the greatest relative impact on summer soil moisture, followed by soil N availability, and light interception. Thinning response studies frequently focus on light availability; our results demonstrate that the response of soil moisture and nutrient availability exceeded that of light availability for the studied forest types.

ПИТАННЯ ДОЦІЛЬНОСТІ ВИКОРИСТАННЯ ТУЇ ВЕЛЕТЕНСЬКОЇ У ЛІСОВОМУ ГОСПОДАРСТВІ РІВНИННОЇ ЧАСТИНИ ЛЬВІВЩИНИ

Відсутність типових лісових об'єктів туї велетенської Thuja plicata D. Don. для досліджень до певної міри компенсовано обстеженням великорозмірної біогрупи цього виду, що сформувалася на місці колишнього розсадника, а також менших біогруп у п'яти парках регіону. Потенційну продуктивність насаджень оцінено за класом бонітету. На всіх ділянках цей показник вищий, ніж у великорозмірній біогрупі туї велетенської у селі Задвір'я, де ріст дерев гальмується наявністю шару мергелю у ґрунті. Ріст найкращих біогруп відповідає І класу бонітету. За результатами виявлених тенденцій рекомендовано тую велетенську для закладання експериментальних лісових насаджень з метою можливості отримання у перспективі більш ґрунтовних висновків щодо широкого використання цього виду в лісових насадженнях.

New Information About the Cypress Weevil,Eudociminus mannerheimii(Boheman, 1836) (Coleoptera: Curculionidae: Molytinae): Redescription, Range Expansion, New Host Records, and Report as a Possible Causative Agent of Tree Mortality

Abstract The cypress weevil, Eudociminus mannerheimii (Boheman, 1836), is reported from northwestern Arkansas (new state record). The suspected host in this area is eastern red cedar (Juniperus virginiana L.), which represents a new host record. Additional new host records from arborvitae (Thuja L.) in North Carolina are reported. A brief redescription of the adult that expands upon the original description and photographs are included. Although cypress weevils are not generally considered pestiferous, a case of landscape trees likely killed by this species is included.

Potential contributions of lignans to decay resistance in western red cedar

Recent work examining the correlations between heartwood extractives in western red cedar and decay resistance in ground-contact field tests identified two compounds that were moderately correlated with decay resistance—plicatic acid and an unknown compound. The aim of the present work was to identify the latter compound and to further probe the correlation between both of these lignans and decay resistance. Chromatographic and mass spectral data indicated that the latter compound was plicatin—the lactone of plicatic acid. Extractives fractions containing plicatic acid, plicatin, and polymeric lignans, believed to be derived from these compounds, were impregnated into ponderosa pine sapwood blocks and evaluated for their ability to resist decay by two brown-rot fungi. Impregnation of plicatic acid, plicatin, their combination, or polymeric western red cedar extractives in pine sapwood did not inhibit decay by the fungi evaluated. However, both plicatic acid and plicatin had high radical scavenging activity, and moderate ferrous iron chelating activity. It is proposed that these compounds contribute to decay resistance not as fungicides, but rather via alternative pathways. These could include interference with redox cycles associated with decay, and restricting moisture by reducing cell wall void volume.

Laboratory Evaluations of Durability of Southern Pine Pressure Treated With Extractives From Durable Wood Species.

Extracts from sawdust of four naturally durable wood species [Alaskan yellow cedar, AYC, Cupressus nootkanansis D. Don 1824; eastern red cedar, ERC, Juniperus virginiana L.; honey mesquite, HM, Prosopis glandulosa Torr.; and black locust, BL, Robinia pseudoacacia L.] were used to treat southern pine, Pt, Pinus taeda L. sapwood blocks. Extractive treated blocks were evaluated for decay resistance in standard soil bottle fungal assays challenged with brown and white rot decay fungi. Results showed that extractives did impart some improvement to decay resistance of Pt blocks. BL- and HM-treated Pt blocks were also used in choice and no-choice assays to determine feeding preference and damage by eastern subterranean termites (Reticulitermes flavipes) Kollar. Minimal feeding on treated blocks was seen in both choice and no-choice assays. In choice assays, there was similar mortality between HM and BL arenas; however, in no-choice assays, complete mortality was recorded for HM-treated Pt and high mortality was seen with BL-treated Pt. Subsequent dose mortality termite assays showed HM to be effective in killing R. flavipes at low concentrations. Both HM and BL show promise as deterrents or termiticidal protectants and will be further evaluated in field studies.

Allergen of the Month—Western Red Cedar

Allergen of the Month—Western Red Cedar

Prediction of the Decay and Termite Resistance of Western Red Cedar Heartwood

Abstract Western red cedar (WRC; Thuja plicata) is highly valued for its natural durability. Rapid methods to assess heartwood durability are needed to identify breeding stock that will ultimately yield trees with durable wood when harvested. Chromatographic methods to detect heartwood extractives have been developed, but these still require significant time and laboratory resources and rely upon an understanding of the relationship between extractives and durability that is still incomplete. Visible/near-infrared (VIS/NIR) spectroscopy combined with multivariate statistical analysis has been used to rapidly predict a wide range of wood properties, including extractive content and decay resistance. The present work investigates the ability of VIS/NIR spectroscopy to predict extractive content, decay resistance, and termite resistance of WRC heartwood and explores the association between extractive content and durability. Partial least squares (PLS) models based on VIS/NIR spectra had moderate predictive ability for lignans, plicatic acid, beta-thujaplicinol, and total extractives. Other extractives were poorly predicted. Developed PLS models were not predictive for decay resistance but were moderately predictive of termite resistance. Decay and termite resistance were not strongly associated with any measured extractive. A moderately strong correlation was observed between termite resistance and red coloration (a*). Some of the models developed may be suitable for screening, but none are accurate enough for phenotyping.