Chemical evaluation of two tropical wood species for use as grilling planks

This research evaluated the possible use of tropical hardwood species (Myrocarpus frondosus and Ocotea porosa) for grilling plank production. Physical, chemical, and organoleptic properties were evaluated and compared with properties of a well-used wood species for grilling planks, western red cedar (Thuja plicata). For chemical analysis, one technique was used: hydrodistillation. Normality tests and analyses of variance (ANOVA) were used for the comparisons between Thuja plicata and tropical hardwoods. The results of the organoleptic, chemical, and statistical analyses demonstrated the possibility of using Myrocarpus frondosus and Ocotea porosa in grilling plank production.

Genomic evidence of an ancient Inland Temperate Rainforest

The disjunct temperate rainforests of the Pacific Northwest of North America (PNW) are characterized by late-successional dominant tree species western redcedar (Thuja plicata) and western hemlock (Tsuga heterophylla). The demographics of these species, along with the PNW rainforest ecosystem in its entirety, have been heavily impacted by the geological and climatic changes the PNW has experienced over the last 5 million years, including mountain orogeny and repeated Pleistocene glaciations. These environmental events have ultimately shaped the history of these species, with inland segments potentially being extirpated during the Pleistocene glaciation. Here, we collect genomic data for both species across their ranges in order to develop multiple demographic models, each reflecting a different hypothesis on how the ecosystem dominant species may have responded to dramatic climatic change. Results indicate that inland and coastal populations in both species diverged an estimated ~2.5 million years ago and experienced a decrease in population size during glaciation, with a subsequent population expansion. Importantly, we found evidence for gene-flow between coastal and inland populations during the mid-Holocene. It is likely that intermittent migration in these species has prevented allopatric speciation. In conclusion, the combination of genomic data and population demographic inference procedures involving machine learning establish that populations of the ecosystem dominants Thuja plicata and Tsuga heterophylla persisted in refugia located in both the coastal and inland regions, with populations expanding and contracting in response to glacial cycles with occasional gene-flow.

Species diversification of the coniferous pathogenic fungal genus Coniferiporia (Hymenochaetales, Basidiomycota) in association with its biogeography and host plants

Coniferiporia, belonging to Hymenochaetaceae and recently segregated from Phellinidium, is a wood-inhabiting fungal genus with three species, each having a specific geographic distribution and a strong host specificity as a forest pathogen of coniferous trees. In this study, the species diversity of Coniferiporia is further clarified with the aid of a wider sampling and multilocus-based phylogenetic analysis, which reveals a new species C. uzbekistanensis. The molecular clock and ancestral geographic origin analyses indicates that the ancestor of Coniferiporia emerged in one of the Pinaceae and Cupressaceae and then jumped to the other plant family originated in eastern Eurasia 17.01 million years ago (Mya) (95% highest posterior density: 9.46–25.86 Mya) and later extended its distribution to western North America, Central Asia and eastern Europe. Coniferiporia sulphurascens speciated on Pinaceae in eastern Eurasia 8.78 Mya (9.46–25.86 Mya) and then extended its distribution to western North America and eastern Europe. Coniferiporia qilianensis and C. uzbekistanensis speciated on Juniperus przewalskii in eastern Eurasia 3.67 Mya (0.36–8.02 Mya) and on J. polycarpos in Central Asia 4.35 Mya (0.94–8.37 Mya), respectively. The speciation event of C. weirii occurred 4.45 Mya (0.77–9.33 Mya) right after the emergence of its host, the endemic Cupressaceae species Thuja plicata, and soon after, this fungus evolved to also inhabit another endemic Cupressaceae species Calocedrus decurrens. In summary, this study for the first time unambiguously clarified and timed the adaptive evolutionary event of Coniferiporia in association with its biogeography and host plants.

EPR Spectroscopy as a Tool to Characterize the Maturity Degree of Humic Acids

The major indicator of soil fertility and productivity are humic acids (HAs) arising from decomposition of organic matter. The structure and properties of HAs depend, among others climate factors, on soil and anthropogenic factors, i.e., methods of soil management. The purpose of the research undertaken in this paper is to study humic acids resulting from the decomposition of crop residues of wheat (Triticum aestivum L.) and plant material of thuja (Thuja plicata D.Don.ex. Lamb) using electron paramagnetic resonance (EPR) spectroscopy. In the present paper, we report EPR studies carried out on two types of HAs extracted from forest soil and incubated samples of plant material (mixture of wheat straw and roots), both without soil and mixed with soil. EPR signals obtained from these samples were subjected to numerical analysis, which showed that the EPR spectra of each sample could be deconvoluted into Lorentzian and Gaussian components. It can be shown that the origin of HAs has a significant impact on the parameters of their EPR spectra. The parameters of EPR spectra of humic acids depend strongly on their origin. The HA samples isolated from forest soils are characterized by higher spin concentration and lower peak-to-peak width of EPR spectra in comparison to those of HAs incubated from plant material.

Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio

Mixed-species plantations have been suggested as ecologically and economically viable alternatives to monocultures. We examined the growth response of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) and western redcedar (Thuja plicata Donn ex D. Don in Lamb.) to different species mixtures (Douglas-fir : western redcedar mixtures of 1:0, 1:1, 1:3, and 0:1) and planting densities (500, 1000, and 1500 stems·ha−1) in a dry maritime forest on eastern Vancouver Island, Canada. Twenty-two years postplanting, species mixture significantly affected diameter and height growth (p < 0.001), with stand diameter and height generally decreasing with increasing redcedar composition. Inherent variation in soil productivity across the plantation (carbon:nitrogen ratio) equally constrained stand growth. The widest spacing had larger diameter than the closest spacing (p = 0.025) but the least stand basal area compared with the other spacing treatments (p = 0.003–0.031). Stand volume was significantly affected by mixture × density interaction (p = 0.024) and generally declined with increasing proportion of redcedar and decreasing stand density. In the first decades after plantation establishment, inherent species growth traits and soil fertility were most important in dictating stand productivity. Because of the differences in resource utilization of both species, stand dynamics may change as competition for light and soil resources increases. Evaluation of silvicultural recommendations regarding mixtures of both species will continue with plantation development.

Macrofungi on Three Nonnative Coniferous Species Introduced 130 Years Ago, Into Warmia, Poland

In fall 2018 and 2019, we assessed colonization by fungi on Douglas fir trees [<em>Pseudotsuga menziesii </em>(Mirb.) Franco], white pine (<em>Pinus strobus </em>L.), and red cedar (<em>Thuja plicata </em>D. Don.) on selected experimental plots of the former Prussian Experimental Station, where nonnative tree species were introduced from North America over a century ago. The presence of sporocarps on trunks, root collars, and stumps as well as the litter layer in the soil within a radius of 0.5 m around the trunk of the tree was determined. Additionally, the volume of dead wood on the forest floor of the entire plot was assessed. We recorded numerous fungi on trees and stumps as well as in the litter and soil. For the 31 plots in 12 forest districts, we determined 745 sporocarps of 48 taxa, with 335/19 on the wood of <em>P. menziesii </em>trees and stumps, 377/15 on <em>P. strobus</em>, and 33/6 on <em>T. plicata </em>trees. The highest share of trees with various trunk damage levels was found for <em>T. plicata </em>(70.3%) and the lowest for <em>P. menziesii </em>(6.2%). Among the root parasitic fungi, <em>Heterobasidion </em>sp. and <em>Armillaria </em>sp. were found, especially on the collars and stumps of <em>T. plicata </em>and <em>P. strobus</em>; we did not find basidiomata of both pathogens on <em>P. menziesii</em>. The volume of dead wood within the <em>P. menziesii </em>plots averaged 7.1 m3/ha, whereas in <em>T. plicata </em>plots, it was 56.3 m3/ha. We identified 10 taxa that have not been reported in association with <em>P. strobus </em>for Poland (<em>Cylindrobasidium laeve</em>, <em>Dacrymyces </em>sp., <em>Exidia pithya</em>, <em>E. saccharina</em>, <em>Gymnopilus pnetrans</em>, <em>Leptoporus mollis</em>, <em>Mycena sanguinolenta</em>, <em>Tapinella panuoides</em>, <em>Trametes versicolor</em>, and <em>Xylaria hypoxylon</em>) and three taxa (<em>Exidia pithya</em>, <em>Leptoporus mollis</em>, <em>Serpula himantioides</em>) associated with <em>T. plicata</em>.

Wood Products for Cultural Uses: Sustaining Native Resilience and Vital Lifeways in Southeast Alaska, USA

Ongoing revitalization of the >5000-year-old tradition of using trees for vital culture and heritage activities including carving and weaving affirms Alaska Native resilience. However, support for these sustained cultural practices is complicated by environmental and political factors. Carving projects typically require western redcedar (Thuja plicata) or yellow cedar (Callitropsis nootkatensis) trees more than 450 years of age—a tree life stage and growth rate inconsistent with current even-aged forest management strategies. Herein, we qualitatively assess the significance of wood products to rural communities and Indigenous cultures with implications for natural heritage sustainability. In partnership with Alaska Native Tribes, we engaged local youth programs to lead community discussions throughout southeast Alaska to provide specificity to the suite of cultural activities linked to regional forest lands. Results from 58 discussions across 11 southeast Alaska communities (primarily Alaska Native participants) highlighted the cultural importance of forest products including totem poles, dugout canoes, longhouses, woven hats, and woven baskets. Findings indicated spiritual well-being, health, education, tourism, and livelihood significance attributed to these products. Participant-suggested management strategies for increasing supply and expanding access to trees on public lands included: engaging local artisans in forest planning, selecting and delivering specific trees to roads as part of ongoing timber sales, allowing bark removal prior to forest-timber sales, simplifying the tree-acquisition permit process, and setting aside cultural forest groves to sustain trees seven generations into the future. By facilitating discussions, this study fostered relevant place-based youth and community engagement, benefiting youth and enhancing community knowledge transfer while simultaneously summarizing the significance of forest products for resilient culture and heritage activities. Forest management plans aiming to support Alaska Native lifeways may benefit from improved understanding of Indigenous perspectives and worldviews; designation of “culture market values” and “culture targets” can help deliver a broad array of ecosystem services.

Influence of moisture, nutrients, and distance from stream on early-stage mass loss of western red cedar leaf litter in headwater riparian forests

Western red cedar (Thuja plicata Donn ex D.Don) is a dominant species in forests of the Pacific Northwest in North America, but little is known about its decomposition in riparian habitat. We experimentally tested how early-stage mass loss of cedar leaf litter varied with distance from the stream (five distances from 1 to 40 m away) and responded to nutrient and water additions near four headwater streams in southwestern British Columbia. We ran three coarse-mesh litterbag trials in durations between five months to one year from January 2013 and January 2014. Litterbags were either untreated or given the following treatments: water additions during dry summer months, nitrogen and phosphorus additions, or additions of both. Control litterbags lost 21% initial mass over 12 months (January 2013 – January 2014), 20% over five months (January 2013 – June 2013), and 15% over eight months (June 2013 – January 2014). Rates of mass loss did not increase with water in any trial but did increase with nutrients in the 12-month trial. Litter located 40 m from the stream lost 7% more mass than that located 1 m away in this same trial. Our study indicates that cedar leaf litter mass loss responded primarily to nutrient additions.

Identification of Three Monofunctional Diterpene Synthases with Specific Enzyme Activities Expressed during Heartwood Formation in Western Redcedar (Thuja plicata) Trees

Upon harvest, Western redcedar (WRC; Thuja plicata) trees have a high incidence and extent of heartwood rot. While monoterpenoids and lignans have been linked to rot resistance in this species, other specialized metabolites, such as diterpenes, are likely to contribute to rot resistance. Here we report the cloning and functional assessment of three putative diterpene synthase (TpdiTPS) genes expressed during heartwood formation in WRC. The predicted proteins of the three genes lack either of the two catalytically independent active sites typical of most diTPS, indicating monofunctional rather than bifunctional activity. To identify potential catalytic activities of these proteins, we expressed them in genetically engineered Escherichia coli strains that produce four potential substrates, geranylgeranyl diphosphate (GGDP), ent, syn, and normal stereoisomers of copalyl diphosphate (CDP). We found that TpdiTPS3 used GGDP to produce CDP. TpdiTPS2 used normal CDP to produce levopimaradiene. TpdiTPS1 showed stereoselectivity as it used normal CDP to produce sandaracopimaradiene and syn-CDP to produce syn-stemod-13(17)-ene. These genes and protein enzymatic activities have not been previously reported in WRC and provide an opportunity to assess their potential roles in heartwood rot resistance in this economically important species.

Selfing and correlated paternity in relation to pollen management in western red cedar seed orchards

We used microsatellite genetic markers to evaluate the mating system of western red cedar (Thuja plicata Donn ex D. Don) under various seed orchard pollen management schemes. We primarily examined whether supplemental mass pollination (SMP) can reduce the observed selfing rates. Pollen blowing and “hooding” were also examined in smaller tests. Only SMP was consistently effective in reducing the selfing rate, from 30% to 20%. The correlation of paternity was quite high (60%–90%) in two of three orchards, and in these two orchards the application of SMP reduced this correlation by about 10% as well. The correlation of paternity is the fraction of full-sibling vs. half-sibling progeny, and unbiased estimates can be obtained with few loci, even single loci, in contrast to other types of paternity analysis. We also find the microsatellite amplicon sizes should be pooled into “bins” of 2–4 nucleotides, owing to unintended errors of assay; otherwise the estimates are biased. This new feature of mating system estimation was incorporated into the computer program MLTR.