Western White Pine Research Articles

Climate Impacts on Tree Growth in the Sierra Nevada

Rising temperatures and aridity may negatively impact tree growth, and therefore ecosystem services like carbon sequestration. In the Sierra Nevada in California, annual variation in precipitation is high, and forests have already been impacted by several recent severe droughts. In this study, we used growth census data from long-term plots in the Sierra Nevada to calibrate an annual climate-dependent growth model. Our results highlight a high diversity of responses to climate, although the effects of climate are small compared to those of tree size and competition. Some species grow less during dry years (Pinus contorta and Calocedrus decurrens) but, surprisingly, other species exhibit higher growth during dry years (Pinus monticola, Abies magnifica, Pinus jeffreyi, Quercus kelloggii). These results emphasize the need for growth models to take into account species variability, as well as spatial heterogeneity, when studying mixed conifer forests. So far, temperatures have increased in California, and tree growth of some species may drastically decrease in the Sierra Nevada if warming continues, leading to changes in forest structure and composition as well as potential changes in wood production and carbon sequestration.

Expression analysis of thaumatin-like proteins from Bursaphelenchus xylophilus and Pinus massoniana

The pine wood nematode Bursaphelenchus xylophilus has caused enormous economic losses in forests of many countries in the world. Many scientists have studied this disease, but the pathogenesis is still not fully understood. Our previous study showed that the thaumatin-like protein of B. xylophilus (Bx-TLP-1) was most similar to that of western white pine (TLP-S3: ADB97933.1) in structure and homology. To further explore the role of the thaumatin-like protein in the interaction of B. xylophilus with host pine, we cloned gene that encodes the thaumatin-like protein from Pinus massoniana, named Pm-tlp (gene accession number: KM063439). The deduced protein contains 180 amino acids, including 10 conserved cysteine residues. We also analyzed the expression of the two proteins from pine wood nematode and pine (roots, stems and needles) after inoculation with B. xylophilus. We found that over a month, the peaks of Bx-tlp-1 expression alternated with those of Pm-tlp. Furthermore, the first Bx-tlp-1 expression peak was earlier than Pm-tlp expression in stems and needles. In addition, we found that the α-pinene content corresponded with the expression of Bx-tlp-1 and Pm-tlp expression over the evaluated time course. The results showed that Bx-tlp-1 may interfere with the expression of Pm-tlp and the defense system to achieve its parasitism in the host, which may further influence the pinene content. These results provide information for further study of the function of thaumatin-like proteins in the interaction of B. xylophilus with P. massoniana.

Prioritizing Young Western White Pine Stands for Blister Rust Pruning on the Warm Springs Reservation

Prioritizing Young Western White Pine Stands for Blister Rust Pruning on the Warm Springs Reservation

Saturated genic SNP mapping identified functional candidates and selection tools for the Pinus monticola Cr2 locus controlling resistance to white pine blister rust.

SummaryMolecular breeding incorporates efficient tools to increase rust resistance in five‐needle pines. Susceptibility of native five‐needle pines to white pine blister rust (WPBR), caused by the non‐native invasive fungus Cronartium ribicola (J.C. Fisch.), has significantly reduced wild populations of these conifers in North America. Major resistance (R) genes against specific avirulent pathotypes have been found in several five‐needle pine species. In this study, we screened genic SNP markers by comparative transcriptome and genetic association analyses and constructed saturated linkage maps for the western white pine (Pinus monticola) R locus (Cr2). Phenotypic segregation was measured by a hypersensitive reaction (HR)‐like response on the needles and disease symptoms of cankered stems post inoculation by the C. ribicola avcr2 race. SNP genotypes were determined by HRM‐ and TaqMan‐based SNP genotyping. Saturated maps of the Cr2‐linkage group (LG) were constructed in three seed families using a total of 34 SNP markers within 21 unique genes. Cr2 was consistently flanked by contig_2142 (encoding a ruvb‐like protein) and contig_3772 (encoding a delta‐fatty acid desaturase) across the three seed families. Cr2 was anchored to the Pinus consensus LG‐1, which differs from LGs where other R loci of Pinus species were mapped. GO annotation identified a set of NBS‐LRR and other resistance‐related genes as R candidates in the Cr2 region. Association of one nonsynonymous SNP locus of an NBS‐LRR gene with Cr2‐mediated phenotypes provides a valuable tool for marker‐assisted selection (MAS), which will shorten the breeding cycle of resistance screening and aid in the restoration of WPBR‐disturbed forest ecosystems.

Adaptive response of Pinus monticola driven by positive selection upon resistance gene analogs (RGAs) of the TIR-NBS-LRR subfamily

Abstract: Western white pine (Pinus monticola Dougl.) is an important forest tree species, which is intensively plagued by the fungus Cronartium ribicola. Resistance gene analogs (RGAs) are the most highly abundant class of potential resistance (R) genes sharing greatly conserved domains and structures. Hence RGAs are crucial components for disease resistance breeding programs on P. monticola serving as useful functional markers. A total of 33 P. monticola RGAs gene homologues were mined from GenBank, encoding for R gene members of the TIR-NBS-LRR subfamily. The existence of positive selection acting upon RGAs was determined using a series of maximum likelihood analyses. Robust evidence of positive selection was showed to be acting widely in three clades across RGA gene phylogeny, both on terminal and ancestral lineages. Furthermore, our analysis revealed that the majority of positively selected residues sites are localized widely across these RGAs sequences, putatively affecting the structures of their ligand-binding domains and offering novel specificities. These results may find immediate application in ongoing disease resistance breeding programs.

Conifer Diet Choices Made by Mule Deer (Odocoileushemionus) of North Central British Columbia During a Cafeteria-Style Feeding Trial

The winter diets of northern mule deer are comprised predominantly of shrubs and trees. Included in winter diets are various species of conifers, some of which are important forestry and ornamental crop trees. Diet choices and feeding habits of mule deer utilizing conifer crops, however, have not been widely reported. Here, we document diet choices made by human-habituated mule deer from north central British Columbia during an exploratory cafeteria-style feeding trial using boughs of thirteen species of native North American and introduced European conifers. Mule deer consumed more biomass from exotic conifers (specifically pine) than from rarely encountered native conifers, and consumed the least biomass from those native conifers commonly encountered by deer in northern BC, a finding which appears to lend support to the Biotic Resistance Hypothesis. From most to least biomass consumed, deer selected Mugho pine, Scots pine, western hemlock, subalpine fir, Douglas fir, Norway spruce, Ponderosa pine, western white pine, lodgepole pine, common juniper, red cedar, black spruce, and hybrid white spruce. Analysis of Variance testing suggested that deer preferred to eat exotic Mugho and Scots pine and avoided eating commonly encountered, native black and hybrid white spruce. A relationship also existed between the biomass consumed and the number of bites taken by deer from each species, which generally indicated that deer took more bites from exotic and rarely encountered conifers, but not always. Our results suggest that northern mule deer, therefore, may be more likely to damage introduced pine and other exotics relative to native species planted in either ornamental or forest plantation settings when deer densities are high and/or browse resources are limited.

Deladenus posteroporus n. sp. (Nematoda: Neotylenchidae) Isolated from Packaging Wood from Canada and White Pine (Pinus monticola) Lumber from the United States and Intercepted in Ningbo, China.

The new species is characterized by the posteriorly positioned excretory pore relative to the hemizonid in both mycetophagous and infective forms, by a broadly rounded tail end in mycetophagous females and lateral fields with 11 to 12 lines midbody in both mycetophagous females and males. The partial 18S, complete internal transcribed spacer, and partial 28S D2/D3 rRNA genes were amplified and sequenced. Phylogenetic analyses of the genes grouped the new species with previously sequenced species of Deladenus in a fully supported clade. This is the first report of Deladenus species with a known infective stage to have the excretory pore positioned posterior to the hemizonid.

First Report of Fusarium proliferatum Causing Fusarium Root Disease on Sugar Pine (Pinus lambertiana) in a Forest Container Nursery in California

Fusarium species, specifically F. commune, F. proliferatum, and F. solani, can cause severe damping-off and root disease in container and bareroot forest nurseries throughout North America. Many conifer and hardwood species can be affected, but Douglas-fir (Pseudotsuga menziesii), western white pine (Pinus monticola), and ponderosa pine (P. ponderosa) are known to be susceptible to Fusarium root disease (Stewart et al. 2012).

Grand Fir Nutrient Management in the Inland Northwestern USA

Grand fir (Abies grandis (Douglas ex D. Don) Lindley) is widely distributed in the moist forests of the Inland Northwest. It has high potential productivity, its growth being nearly equal to western white pine, the most productive species in the region. There are large standing volumes of grand fir in the region. Nutritionally, the species has higher foliage cation concentrations than associated conifers, especially potassium (K) and calcium (Ca). In contrast, it has lower nitrogen (N) foliage concentrations, which creates favorable nutrient balance on N-limited sites. Despite concentration differences, grand fir stores proportionally more nutrients per tree than associated species because of greater crown biomass. Although few fertilization trials have examined grand fir specifically, its response is inferred from its occurrence in many monitored mixed conifer stands. Fertilization trials including grand fir either as a major or minor component show that it has a strong diameter and height growth response ranging from 15% to 50% depending in part on site moisture availability and soil geology. Grand fir tends to have a longer response duration than other inland conifers. When executed concurrently with thinning, fertilization often increases the total response. Late rotation application of N provides solid investment returns in carefully selected stands. Although there are still challenges with the post-fertilization effects on tree mortality, grand fir will continue to be an important species with good economic values and beneficial responses to fertilization and nutrient management.

Composition, Antifungal and Antifumonisin Activity of Pinus wallichiana, Pinus monticola and Pinus strobus Essential Oils from Patagonia Argentina

The essential oils composition of Pinus wallichiana, P. monticola and P. strobus was determined by GC-FID and GC-MS analysis. P. wallichiana was the species with the highest essential oils production with an average yield of 0.97 %, followed by P. monticola and P. strobus with 0.58 and 0.50 % (v/dry wt). The main compounds with concentration higher than 5.0 % were the monoterpene hydrocarbons: α-pinene (14.8–21 %), β-pinene (22.8–34 %), limonene (4.6–17.8 %) and myrcene (1.6–12.3 %). The essential oils from P. wallichiana and P. monticola in comparison to P. strobus have been characterized by a higher content of limonene (17.8, 14.0 and 4.6 %, respectively). On the other hand, the essential oil of P. strobus showed high levels of myrcene and oxygenated and hydrocarbons sesquiterpenes. All of the evaluated essential oils showed some inhibitory effects on the growth of F. verticillioides. However, none of the evaluated EOs significantly altered the FB1 production under the experimental conditions.Pinus wallichiana, Pinus monticola, Pinus strobus, essential oils composition, antifungal, fumonisin.

Landscape Biology of Western White Pine: Implications for Conservation of a Widely-Distributed Five-Needle Pine at Its Southern Range Limit

Throughout much of the range of western white pine, Pinus monticola Dougl., timber harvesting, fire exclusion and the presence of Cronartium ribicola J. C. Fisch., the white pine blister rust (WPBR) pathogen, have led to negative population and genetic consequences. To address these interactions, we examined population dynamics and genetic diversity in 10 populations of western white pine in upper montane forests of the Lake Tahoe Basin. We documented negative population trends for three of the 10 populations. These populations exhibited low estimated growth rates (λ), moderate to high incidences of WPBR and mountain pine beetle (MPB), and high levels of mortality. In contrast, seven populations appear to be stable (λ ≥ 1.0), with low to moderate disease and insect incidence, and evidence for genetic resistance to WPBR. Genetic diversity (HE) for a set of 160 single nucleotide polymorphisms was in the range of 0.245–0.272 across populations, and population-specific estimates of FST ranged from 0.0062 to 0.0244. Allele frequency of the Cr2 gene, which confers complete resistance to C. ribicola in western white pine, was low, averaging 0.009 for all populations sampled. However, a low frequency of pollen receptors (i.e., susceptible maternal parents pollinated by a local resistant parent) was found in nine of 10 populations. A moderate and negative relationship was found between the frequency of pollen receptors in a population and the incidence of WPBR (r2 = 0.32). In the context of an introduced pathogen, climate driven outbreaks of MPB, fire exclusion, and prolonged drought, conservation and management strategies are warranted for this species in the Lake Tahoe Basin and likely other locations in California. These strategies include gene conservation of western white pine, WPBR resistance screening, and forest restoration treatments.

Effects of Grosmannia clavigera and Leptographium longiclavatum on Western White Pine Seedlings and the Fungicidal Activity of Alamo®, Arbotect®, and TREE-äge®

Bark beetles carry a number of associated organisms that are transferred to the host tree upon attack that are thought to play a role in tree decline. To assess the pathogenicity to western white pine (WWP; Pinus monticola) of fungi carried by the mountain pine beetle (MPB; Dendroctonus ponderosae), and to evaluate the potential for systemic prophylactic treatments for reducing fungal impacts, experiments were conducted with WWP seedlings to meet three objectives: 1) evaluate pathogenicity of two MPB-associated blue-stain fungi; 2) evaluate phytotoxicity of tree injection products; 3) evaluate the anti-fungal activity of tree injection products, in vitro and in vivo, toward the associated blue-staining fungi. To evaluate pathogenicity, seedlings were inoculated with Grosmannia clavigera or Leptographium longiclavatum, common fungal associates of MPB. Seedling mortality at four months after inoculation was 50% with L. longiclavatum and 90% with G. clavigera, both significantly higher than controls and thereby demonstrating pathogenicity. Phytotoxic effects of TREE-äge®, Alamo®, and Arbotect® were evaluated by stem injection; no phytotoxic effects were observed. Anti-fungal properties of the same three products were evaluated in vitro against G. clavigera, where Alamo was most active. Co-inoculation of G. clavigera and L. longiclavatum into seedlings after a stem injection of Alamo showed significantly less mortality and lesion formation than either species alone. Results support the hypothesis that MPB blue-stain associates, particularly G. clavigera, promote death of WWP when attacked by MPB. These findings suggest that the administration of a fungicide with insecticide for tree protection against bark beetles may be advantageous.

Quantifying density-independent mortality of temperate tree species

Forest resilience to climate change is a topic of national concern as our standing assets and future forests are important to our livelihood. Many tree species are predicted to decline or disappear while others may be able to adapt or migrate. Efforts to quantify and disseminate the current condition of forests are urgently needed to guide management and policy. Here, we develop a new indicator to summarize raw density-independent mortality of forested stands by species from the last decade of the 20th century to the first decade of the 21st century using forest inventory data. We define density-independent mortality to be stand mortality by species due to processes unrelated to natural mortality from succession or stand maturation, which is marked by overall increase in tree girth at the expense of density of individuals. We assess trends for 22 species on national forests in two U.S. states, Washington and Oregon. Populations of some species including timber species have no or low overall levels of density-independent mortality (Juniperus occidentalis, Abies procera, Thuja plicata, Tsuga heterophylla, Pinus ponderosa, and Pseudotsuga menziesii). In contrast, other species demonstrate unsustainable levels of density-independent mortality (Pinus monticola, Arbutus menziesii, Pinus albicaulis, Abies lasiocarpa, Taxus brevifolia, Pinus contorta, Abies grandis, Picea englemanii, and Larix occidentalis). Additionally, the net potential for unsustainable levels of density-independent mortality in standing populations does not necessarily warrant concern when examined across species for our study area and time period; however, when examined by species, the number of species in decline exceeds the number of species where mortality can be generally attributed to endogenous self-thinning. We argue that this work can aid management and policy decisions and our understanding of complex vegetation dynamics in a changing climate. Application of the indicator at larger spatial scales and in conjunction with data on migration and establishment may be used to address questions such as, how can we make cost-effective management decisions to ensure long-term sustainability of tree species and forests? Tree species distributions across the landscape are complex systems, and raw characterization of current trends occurring in forest inventories is important especially given the uncertainty associated with the modeling and prediction of complex systems such as tree species.

Olfactory Responses of the Hemlock Woolly Adelgid Predator,Laricobius nigrinus(Coleoptera: Derodontidae), to Natural and Synthetic Conifer Volatiles

Abstract Laricobius nigrinus Fender (Coleoptera: Derodontidae) is a specialist predator of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), native to the Pacific Northwest. It has been introduced into the eastern United States for biological control of exotic hemlock woolly adelgid populations that threaten native hemlock. The possible role of olfactory cues in host finding by this predator has received little study. We used gas chromatography–electroantennographic detection (GC-EAD) to test adult L. nigrinus olfactory sensitivity to volatiles from foliage of both adelgid-infested and uninfested eastern hemlock [Tsuga canadensis (L.) Carriere] and western hemlock [Tsuga heterophylla (Raf.) Sarg.], and two hemlock woolly adelgid nonhost species (eastern white pine, Pinus strobus L., and western white pine, Pinus monticola Douglas ex D. Don). Adelgid infestation did not alter L. nigrinus EAD response profiles to volatiles from either hemlock species. In total, antennal preparations...

Bark Thickness Equations for Mixed-Conifer Forest Type in Klamath and Sierra Nevada Mountains of California

We studied bark thickness in the mixed-conifer forest type throughout California. Sampling included eight conifer species and covered latitude and elevation gradients. The thickness of tree bark at 1.37 m correlated with diameter at breast height (DBH) and varied among species. Trees exhibiting more rapid growth had slightly thinner bark for a given DBH. Variability in bark thickness obscured differences between sample locations. Model predictions for 50 cm DBH trees of each species indicated that bark thickness was ranked Calocedrus decurrens > Pinus jeffreyi > Pinus lambertiana > Abies concolor > Pseudotsuga menziesii > Abies magnifica > Pinus monticola > Pinus contorta. We failed to find reasonable agreement between our bark thickness data and existing bark thickness regressions used in models predicting fire-induced mortality in the mixed-conifer forest type in California. The fire effects software systems generally underpredicted bark thickness for most species, which could lead to an overprediction in fire-caused tree mortality in California. A model for conifers in Oregon predicted that bark was 49% thinner in Abies concolor and 37% thicker in Pseudotsuga menziesii than our samples from across California, suggesting that more data are needed to validate and refine bark thickness equations within existing fire effects models.

The benefits of recycling: how photosynthetic bark can increase drought tolerance.

[Extract] Understanding the drought physiology of woody plants has become an increasingly important focus of plant science research in recent years, spurred on by concern about the potential for widespread tree mortality in response to drought stress caused by global warming (McDowell et al., 2008; Allen et al., 2010). However, there is one aspect of how woody plants cope with water deficits that has received very little attention: the role of carbon fixation by photosynthetic bark. This process may become especially important for maintaining physiological activity in woody tissues of drought-stressed trees as the supply of photosynthate from leaves dwindles, due to stomatal closure and impaired phloem translocation. In this issue of New Phytologist, Vandegehuchte et al. (pp. 998–1002) bring this process into the spotlight, and provide a compelling argument for why we should take more notice of that often-hidden, green layer of tissue that is ubiquitous beneath the smooth-bark surfaces of woody plants (Scott, 1907; Pfanz et al., 2002; Dima et al., 2006; Rosell et al., 2015).

Transcriptome analysis of the white pine blister rust pathogen Cronartium ribicola: de novo assembly, expression profiling, and identification of candidate effectors.

BackgroundThe fungus Cronartium ribicola (Cri) is an economically and ecologically important forest pathogen that causes white pine blister rust (WPBR) disease on five-needle pines. To cause stem cankers and kill white pine trees the fungus elaborates a life cycle with five stages of spore development on five-needle pines and the alternate host Ribes plants. To increase our understanding of molecular WP-BR interactions, here we report genome-wide transcriptional profile analysis of C. ribicola using RNA-seq.ResultscDNA libraries were constructed from aeciospore, urediniospore, and western white pine (Pinus monticola) tissues post Cri infection. Over 200 million RNA-seq 100-bp paired-end (PE) reads from rust fungal spores were de novo assembled and a reference transcriptome was generated with 17,880 transcripts that were expressed from 13,629 unigenes. A total of 734 unique proteins were predicted as a part of the Cri secretome from complete open reading frames (ORFs), and 41 % of them were Cronartium-specific. This study further identified a repertoire of candidate effectors and other pathogenicity determinants. Differentially expressed genes (DEGs) were identified to gain an understanding of molecular events important during the WPBR fungus life cycle by comparing Cri transcriptomes at different infection stages. Large-scale changes of in planta gene expression profiles were observed, revealing that multiple fungal biosynthetic pathways were enhanced during mycelium growth inside infected pine stem tissues. Conversely, many fungal genes that were up-regulated at the urediniospore stage appeared to be signalling components and transporters. The secreted fungal protein genes that were up-regulated in pine needle tissues during early infection were primarily associated with cell wall modifications, possibly to mask the rust pathogen from plant defenses.ConclusionThis comprehensive transcriptome profiling substantially improves our current understanding of molecular WP-BR interactions. The repertoire of candidate effectors and other putative pathogenicity determinants identified here are valuable for future functional analysis of Cri virulence and pathogenicity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1861-1) contains supplementary material, which is available to authorized users.

Using direct amplification and next-generation sequencing technology to explore foliar endophyte communities in experimentally inoculated western white pines

Abstract Fungal endophytes can influence survivability and disease severity of trees. Here we characterized the endophyte community in Pinus monticola (western white pine), an important species in the northwest USA, largely decimated by pathogenic fungi. We also assessed the ability to successfully inoculate seedlings with desirable endophytes, with the long-term goal of providing a protective microbiome and added defense from pathogens. P. monticola seedlings were inoculated in the field with potential pathogen antagonists and fungi isolated from healthy mature trees. Following inoculations direct amplification and next generation sequencing were used to characterize fungal endophyte communities, and explore interspecific competition, diversity, and co-occurrence patterns in needle tissues. Negative co-occurrence patterns between inoculated fungi and potential pathogens, as well as many other species, suggest early competitive interactions. Our study explores early endophyte community assemblage and shows that fungal inoculations may influence tree growth.

Contrasting patterns of genetic diversity across the ranges of Pinus monticola and P. strobus: a comparison between eastern and western North American postglacial colonization histories.

• Premises of the study: Understanding the influence of recent glacial and postglacial periods on species' distributions is key for predicting the effects of future environmental changes. We investigated the influence of two physiographic landscapes on population structure and postglacial colonization of two white pine species of contrasting habitats: P. monticola, which occurs in the highly mountainous region of western North America, and P. strobus, which occurs in a much less mountainous area in eastern North America.• To characterize the patterns of genetic diversity and population structure across the ranges of both species, 158 and 153 single nucleotide polymorphism (SNP) markers derived from expressed genes were genotyped on range-wide samples of 61 P. monticola and 133 P. strobus populations, respectively.• In P. monticola, a steep latitudinal decrease in genetic diversity likely resulted from postglacial colonization involving rare long-distance dispersal (LDD) events. In contrast, no geographic patterns of diversity were detected in P. strobus, suggesting recolonization via a gradually advancing front or frequent LDD events. For each species, structure analyses identified two distinct southern and northern genetic groups that likely originated from two different glacial lineages. At a finer scale, and for the two species, smaller subgroups were detected that could be remnants of cryptic refugia.• During postglacial colonization, the western and eastern North American landscapes had different impacts on genetic signatures in P. monticola compared with P. strobus. We discuss the importance of our findings for conservation programs and predictions of species' response to climate change.

Decrease in Sapling Nutrient Concentrations for Six Northern Rocky Mountain Coniferous Species

In the west, fire exclusion, timber harvest, and last century’s climate led to copious regeneration on millions of ha that now need tending. Without treatment, overcrowding increases competition, snow and ice damage potential, and ladder fuels. Limited funding prevents treating all of the affected ha, but by selling small trees for wood pellets, biofuel, or methanol, costs would decrease and more ha could be cleaned. In the northern Rocky Mountains, 8 –10 tree species can occur in young forests, and until this study, information on foliage nutrient concentrations and leaching from saplings for all of these species was limited. We use a mixed-model analysis to examine the change in nutrient concentrations (calcium, magnesium, potassium, carbon, and nitrogen) remaining in saplings for 6 tree species (western white pine, ponderosa pine, western hemlock, western redcedar, Douglas-fir, and grand fir) over a 12-month period. Nutrient concentrations and the pattern of nutrient leaching did vary among the species, but we found that nutrient concentrations did not diminish in the first 200 days and western hemlock was the only species for which nutrient concentrations leached substantially in the 12-month period. Results suggest managers may need to use biomass utilization thresholds to ensure sufficient biomass is left on site to maintain soil productivity.