Picea Breweriana Research Articles

The effects of a half century of warming and fire exclusion on montane forests of the Klamath Mountains, California, USA

AbstractClimate warming and altered disturbance regimes are changing forest composition and structure worldwide. Given that species often exhibit individualistic responses to change, making predictions about the cumulative effects of multiple stressors across environmental gradients is challenging, especially in diverse communities. For example, warming temperatures are predicted to drive species upslope, whereas fire exclusion promotes the expansion of species at lower elevations where fire was historically frequent. We resampled 148 vegetation plots to assess 46 years (1969–2015) of species and community‐level response to warming and fire exclusion in a topographically complex landscape in the Klamath Mountains, California, USA, a diverse region that served as a climate refugia throughout the Holocene. We compared cover and assessed change in the elevational distributions of 12 conifer species at different life stages (i.e., seedlings, saplings, canopy). We observed consistent but non‐significant shifts upward in elevation for eight species, and a significant shift upward for one species, all of which were far less than expectations based on recent warming. Six species declined in total cover and another five declined in at least one life stage, whereas the drought‐ and fire‐intolerant Abies concolor increased by 30.7%. The largest declines were at lower elevations in drought‐tolerant, early‐seral species (Pinus lambertiana and Pinus ponderosa) and at higher elevations for the shade‐tolerant Abies magnifica var. shastensis and the regionally rare Abies lasiocarpa. Regionally rare (Picea engelmannii) and endemic (Picea breweriana) species had reductions in early life stages, portending future declines. Multivariate analyses revealed a high degree of inertia with a minor, but significant, shift in composition and a slight decrease in species turnover along the elevation gradient driven by the expansion of A. concolor. Our results indicate that most species are declining, especially at lower and mid‐elevations where fire exclusion has increased the cover of shade‐tolerant species and reduced the recruitment for fire‐adapted species. Collectively, declines in most species, insufficient upward movement to track warming, reductions in drought‐ and fire‐tolerant early‐seral species, and an increase in a single, shade‐tolerant species will leave these communities maladapted to projected climate scenarios and questions the potential for future climate refugia in this region.

Variation in Results of Three Biology‐Focused Search Engines: A Case Study Using North American Tree Species

Variation in Results of Three Biology‐Focused Search Engines: A Case Study Using North American Tree Species

Rare species and aliens: reconsidering non‐native plants in the management of natural areas

AbstractNatural areas are often managed for the protection of native species and ecosystems. The presence of non‐native species is generally perceived to run counter to these objectives; thus, they are often controlled or tolerated but rarely deliberately favored. We suggest greater emphasis be placed on the role species play in ecological settings regardless of their origin, recognizing that only some non‐native plants are invasive, that the risk of causing ecological harm varies considerably, and that distributions will change as species migrate in response to climate change. We sense a disparity between the way this topic—conservation value of non‐native species—is addressed in the literature and how it is applied in management of natural areas. To encourage more discussion and consideration of appropriate roles for non‐natives in natural areas management, we present five case studies illustrating their value in the conservation of rare and endangered species, including Taylor's checkerspot and island marble butterflies, southwestern willow flycatcher, and the giant kangaroo rat. Our last case study describes a proposed conservation action for the rare Brewer spruce—that of assisted colonization, itself the creation of a non‐native for conservation purposes. Although we support continued avoidance of introducing invasives and a cautious treatment of non‐natives, we encourage those with responsibility for natural areas management to not only evaluate the threats posed by non‐natives, but to also consider their potential benefits in relation to management objectives.

Mitochondrial introgression and complex biogeographic history of the genus Picea

Biogeographic history of plants is much more complex in the Northern Hemisphere than in the Southern Hemisphere due to that both the Bering and the North Atlantic land bridges contributed to floristic exchanges in the Cenozoic, which led to hybridization between congeneric species from different continents. It would be interesting to know how intercontinental gene flow and introgression have affected plant phylogenetic reconstruction and biogeographic inference. In this study, we reinvestigated the phylogenetic and biogeographic history of Picea, a main component of the Northern Hemisphere forest with many species that originated from recent radiation, using two chloroplast (cp), one mitochondrial (mt) and three single-copy nuclear gene markers. The generated gene trees are topologically highly discordant and the geographically closely related species generally show a close affinity of mtDNA rather than cp- or nuclear DNA, suggesting that inter- and intra-continental gene flow and mtDNA introgression might have occurred commonly. However, all gene trees resolved Picea breweriana as the basal-most lineage, which, together with fossil evidence, supports the North American origin hypothesis for the genus. Both dispersal and vicariance have played important roles in the evolution of Picea, and the Bering Land Bridge could have mediated the “North America to Eurasia” dispersal at least two times during the Miocene and Pliocene. Our study again demonstrates the importance of applying data from three genomes for a clear understanding of evolutionary histories in the pine family. Any markers from a single genome alone will not reveal a clear picture of the phylogenetic relationships among closely related congeneric species. In particular, mtDNA markers should be cautiously used, considering that introgression of the maternally inherited mtDNA with a lower rate of gene flow (by seeds) could have occurred much more frequently than that of the paternally inherited cpDNA with a higher rate of gene flow (by pollen) in Pinaceae.

Origin and demographic history of the endemic Taiwan spruce (Picea morrisonicola)

Taiwan spruce (Picea morrisonicola) is a vulnerable conifer species endemic to the island of Taiwan. A warming climate and competition from subtropical tree species has limited the range of Taiwan spruce to the higher altitudes of the island. Using seeds sampled from an area in the central mountain range of Taiwan, 15 nuclear loci were sequenced in order to measure genetic variation and to assess the long-term genetic stability of the species. Genetic diversity is low and comparable to other spruce species with limited ranges such as Picea breweriana, Picea chihuahuana, and Picea schrenkiana. Importantly, analysis using approximate Bayesian computation (ABC) provides evidence for a drastic decline in the effective population size approximately 0.3–0.5 million years ago (mya). We used simulations to show that this is unlikely to be a false-positive result due to the limited sample used here. To investigate the phylogenetic origin of Taiwan spruce, additional sequencing was performed in the Chinese spruce Picea wilsonii and combined with previously published data for three other mainland China species, Picea purpurea, Picea likiangensis, and P. schrenkiana. Analysis of population structure revealed that P. morrisonicola clusters most closely with P. wilsonii, and coalescent analyses using the program MIMAR dated the split to 4–8 mya, coincidental to the formation of Taiwan. Considering the population decrease that occurred after the split, however, led to a much more recent origin.

Projections of suitable habitat under climate change scenarios: Implications for trans‐boundary assisted colonization

Climate change may threaten endemic species with extinction, particularly relicts of the Arcto-Tertiary Forest, by elimination of their contemporary habitat. Projections of future habitat are necessary to plan for conservation of these species. We used spline climatic models and modified Random Forests statistical procedures to predict suitable habitats for Brewer spruce (Picea breweriana), which is endemic to the Klamath Region of California and Oregon. We used three general circulation models and two sets of carbon emission scenarios (optimistic and pessimistic) for future climates. Our procedures predicted present occurrence of Brewer spruce perfectly. For the decades 2030, 2060, and 2090, its projected range within the Klamath Region progressively declined, to the point of disappearance in the decade 2090. The climate niche was projected to move north to British Columbia, the Yukon Territory, and southeastern Alaska. The results emphasize the necessity of assisted colonization and trans-boundary movement to prevent extinction of Brewer spruce. The projections provide a framework for formulating conservation plans, but planners must also consider regulations regarding international plant transfers.

Susceptibility of Conifers to Three Dwarf Mistletoes in the Klamath-Siskiyou Mountains

Abstract Dwarf mistletoes (Arceuthobium spp., Viscaceae) are parasitic flowering plants that infect members of the Pinaceae family in the western United States. This article reports additional host susceptibility data for three dwarf mistletoes found in the Klamath-Siskiyou Mountains of southwestern Oregon and northwestern California. Three mixed conifer stands, each infested with either mountain hemlock dwarf mistletoe, western white pine dwarf mistletoe, or Wiens' dwarf mistletoe (nine stands total) were sampled to evaluate the susceptibility of conifers to these parasites. At each of the study sites, 10–20 temporary circular plots with a 6-m radius (0.012 ha) were established around large, severely infected trees. Within plots, species, dbh, and dwarf mistletoe rating (six-class system) were determined for each live tree. On the basis of the incidence of infection, conifers were assigned to host susceptibility classes. Western white pine and mountain hemlock were principal hosts of western white pine and mountain hemlock dwarf mistletoes, respectively. Brewer spruce and red fir were principal hosts of Wiens' dwarf mistletoe. Other conifers sampled were less susceptible to these mistletoes. This information can be used by forest managers to mitigate the damage associated with infestations of these dwarf mistletoes in mixed conifer forests of the Klamath-Siskiyou Mountains.

Susceptibility of Brewer Spruce (Picea breweriana) to Dwarf Mistletoes (Arceuthobiumspp., Viscaceae)

Abstract Brewer spruce is an endemic of the Klamath and Siskiyou Mountains in southwestern Oregon and northwestern California. Three species of dwarf mistletoes (Arceuthobium spp.) have been reported to parasitize Brewer spruce, but the susceptibility of this spruce to infection by these parasitic plants has received no attention since the late 1960s. The objective of this study is to improve estimates of the susceptibility of Brewer spruce to these parasitic plants in select areas currently supporting highly infected dominant and co-dominant trees. Three mixed conifer stands infested with one of the three dwarf mistletoes known to infect Brewer spruce (nine stands total) were sampled to evaluate the relative susceptibility of this conifer to each mistletoe species. At each of the nine study sites, 10 to 20 temporary circular plots with a 6-m radius (0.012 ha) were established around large, severely infected trees. The following data were collected for each live tree within a plot: species, diameter, and ...

First Report of White Fir Dwarf Mistletoe (Arceuthobium abietinum f. sp. concoloris) on Mexican Spruce (Picea mexicana) in Northern Mexico.

White fir dwarf mistletoe (Arceuthobium abietinum Engelmann ex Munz f. sp. concoloris Hawksw. & Wiens, Viscaceae) severely parasitizes true firs (Abies spp.) from southern Washington to southern California (1). It also occurs in widely isolated populations on white fir (Abies concolor (Gord. & Glend.) Hildebr.) in Nevada, Utah, and Arizona (1). In addition, the two known populations of dwarf mistletoe on Durango fir (Abies durangensis Martínez) in Chihuahua, Mexico (near Yahuirachi and on Cerro Mohinora) have been classified as white fir dwarf mistletoe (1). Although a subspecies of fir dwarf mistletoe (A. abietinum Engelm. ex Munz subsp. wiensii Mathiasen & C. Daugherty) severely parasitizes Brewer spruce (Picea breweriana S. Watson) in northern California and southern Oregon (2), Engelmann spruce (P. engelmannii (Parry) Engelmann), blue spruce (P. pungens Engelm.), and Chihuahua spruce (P. chihuahuana Mart.) have been reported to be immune to infection by white fir dwarf mistletoe in the southwest and Mexico (1). However, in September 2009, white fir dwarf mistletoe was found to be infecting the rare Mexican spruce (P. mexicana Mart.) on Cerro Mohinora in southern Chihuahua, Mexico (25°57'42″N, 107°02'28″W, elevation 3,040 m). Infected Mexican spruces were growing among severely infected Durango firs in a mixed conifer forest of Durango fir, Mexican spruce, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and Mexican white pine (Pinus ayacahuite Ehrenb.). White fir dwarf mistletoe was the only mistletoe present in the forest with the infected Mexican spruces. Only five infected spruces were observed, but some trees had as many as 20 infections. No mortality of Mexican spruce associated with mistletoe infection was observed. Some of the infected spruce branches were producing mature male and female plants with flowers and fruits, respectively. Mistletoe plants collected from Durango fir and Mexican spruce were identical when compared using morphological characters such as plant height (mean 8.4 cm), plant color (yellow-green, green, green-brown, and rarely red-brown), mean diameter of flowers (2.8 mm), and fruit dimensions (5.0 × 3.0 mm). It should be noted that although the dwarf mistletoe parasitizing Durango fir on Cerro Mohinora had been classified as white fir dwarf mistletoe (1), the morphological characters above are slightly different than those reported previously for this mistletoe (1,2). On the basis of the number of infected trees and the light to moderate level of infection observed, Mexican spruce should be tentatively classified as an occasional host of white fir dwarf mistletoe using the host susceptibility classification system proposed by Hawksworth and Wiens (1). Specimens of white fir dwarf mistletoe on Mexican spruce were collected and deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession No. 93827). To my knowledge, this is the first report of white fir dwarf mistletoe parasitizing Mexican spruce and the only know instance of white fir dwarf mistletoe parasitizing a species of spruce found in Mexico (1).

Arceuthobium abietinumSubspeciesWiensii, a New Subspecies of Fir Dwarf Mistletoe (Viscaceae) from Northern California and Southern Oregon

We describe Arceuthobium abietinum subspecies wiensii (Wiens' dwarf mistletoe, Viscaceae), a dwarf mistletoe that severely parasitizes red fir and Brewer spruce in northwestern California and southwestern Oregon. This classification is based on morphological and host range differences between white fir dwarf mistletoe (Arceuthobium abietinum f. sp. concoloris), red fir dwarf mistletoe (Arceuthobium abietinum f. sp. magnificae), and Wien's dwarf mistletoe. Male and female plants of Wiens' dwarf mistletoe were consistently smaller than those of both white fir and red fir dwarf mistletoes, whose plants were about the same size. The shoot color of Wiens' dwarf mistletoe was frequently green-brown or red-brown, while the shoot color of white fir and red fir dwarf mistletoes was typically yellow-green or yellow. Differences in host specificity also distinguish Wiens' dwarf mistletoe from white and red fir dwarf mistletoes.

Regional and local controls on postglacial vegetation and fire in the Siskiyou Mountains, northern California, USA

The Siskiyou Mountains of northwestern California and southwestern Oregon are a floristic hotspot, and the high diversity of conifers there likely results from a combination of geological, ecological, climatological and historical factors. To evaluate how past climate variability has influenced the composition, structure and fire regime of the Siskiyou forests, pollen, charcoal, and lithological evidence was examined from two lakes along a moisture gradient to reconstruct the vegetation, fire and climate history. The late-glacial period was characterized by subalpine parkland and infrequent fire at both sites. During the late-glacial/Early Holocene transition period, subalpine parkland was replaced by a closed forest of Pinus, Cupressaceae, Abies and Pseudotsuga and more frequent fires a 1000 years earlier at the wetter site, and it is likely that reduced Pacific Ocean upwelling created warmer drier conditions at the coast. In the Early Holocene, Pinus, Cupressaceae were less abundant and fire less frequent at the coastal site during a period of increased coastal upwelling and fog production. In the Late Holocene, Abies, Pseudotsuga, Pinus, and Quercus vaccinifolia increased in the forest at both sites suggesting a widespread response to cooling. Fewer fires at the wetter site may account for the abundance of Picea breweriana within the last 1000 years. The comparison of the two records implies that large-scale controls in climate during the last 14,000 cal yr BP have resulted in major changes in vegetation and fire regime. Asynchrony in the ecosystem response of wetter and drier sites arises from small-scale spatial variations in effective moisture and temperature resulting from topographically-influenced microclimates and coastal-to-inland climate gradients.

Genic diversity, genetic structure, and mating system of Brewer spruce (Pinaceae), a relict of the Arcto‐Tertiary forest

Brewer spruce (Picea breweriana), a relict of the widespread Arcto-Tertiary forests, is now restricted to a highly fragmented range in the Klamath Region of California and Oregon. Expected heterozygosity for 26 isozyme loci, averaged over 10 populations, was 0.121. More notable than the relatively high level of diversity when compared to other woody endemics was the strong decrease in expected heterozygosity with latitude. Differentiation (F(ST)) was 0.152, higher than values for many north temperate conifers with larger distributions. The number of migrants per generation (Nm) was 1.34 or 2.70, depending on the method of estimation. Inbreeding appeared low; F(IS) was only 0.003, in agreement with multilocus population outcrossing rates (t(m)), which were generally well above 0.90. No difference in t(m) was found between isolated vs. clustered trees. However, the number of seeds per cone was greatest in the densest populations; t(m) is a measure of effective outcrossing after mortality in the embryonic stage, whereas a reduced number of seeds per cone indicates self pollination. Selfing increased after logging; outcrossing rate before logging was 0.961 and after logging, 0.756. Despite Brewer spruce's narrow, fragmented distribution, the outlook for its conservation was good, with the exception of possible negative effects of logging.

Relationships among the Spruces (Picea, Pinaceae) of Southwestern North America

Abstract Numerous populations from six spruce taxa, including four relict endemics, Picea chihuahuana (Chihuahua spruce), P. martinezii (Martinez spruce), P. mexicana (Mexican spruce), and P. breweriana (Brewer spruce), and two widespread species, P. engelmannii (Engelmann spruce) and P. pungens (blue spruce), were compared at homologous isozyme loci to test various hypotheses about their affinities and origins. Each of the species was clearly separated, and Neighbor-Joining and Unweighted Pair Group analyses of Nei's genetic distance grouped all populations within a taxon into their own clusters. Spruces from Flys Peak, Chiricahua Mountains, Arizona, joined a P. engelmannii cluster and were not a bridge to P. mexicana as previously believed. Spruces from Cerro Mohinora, Chihuahua, were clearly P. mexicana, not phantom hybrids of P. chihuahuana and P. pungens. Nuclear random amplified polymorphic DNA and chloroplast simple sequence repeat and cleaved amplified polymorphic genetic markers were compared in ...

Species differentiation of North American spruce (Picea) based on morphological and anatomical characteristics of needles

Differentiation of most North American spruce (Picea) species can be done based on needle morphology and anatomy. Picea breweriana S. Watson, Picea chihuahuana Martìnez, Picea mariana (Mill.) BSP, Picea martinezii Patterson, and Picea rubens Sarg. needles have two continuous resin ducts extending from near the base to near the tip. Picea engelmannii Parry ex Engelm., Picea glauca (Moench) Voss, Picea pungens Engelm., Picea mexicana Martìnez, and Picea sitchensis (Bong.) Carr. needles have variable numbers of short, intermittent resin ducts or sacs. Within each of these groups, most species could be differentiated based on cross-sectional shape, resin-duct diameter, and resin-duct position. Picea mariana and P. rubens, and P. glauca and P. engelmannii are two pairs with similar needles, but they can be differentiated using linear discriminant analysis based on resin-duct diameter and position in cross section. Paleoecological and paleoclimatological studies may be facilitated by species-level identification of plant macrofossils because of different ecological adaptations of each species. Resin-duct continuity patterns are generally consistent with current taxonomic classifications, except for P. glauca. Based on our results, together with DNA and crossing studies, P. glauca is apparently more closely related to P. engelmannii and P. sitchensis than to P. rubens and P. mariana, with which it is often classified. Picea pungens is probably more distantly related to P. engelmannii than has been assumed in some previous classifications. Picea martinezii and P. chihuahuana may be very closely related to each other.Key words: spruce, Picea, North America, needle, resin duct, anatomy.

Species differentiation of North American spruce (<i>Picea</i>) based on morphological and anatomical characteristics of needles

Differentiation of most North American spruce (Picea) species can be done based on needle morphology and anatomy. Picea breweriana S. Watson, Picea chihuahuana Martinez, Picea mariana (Mill.) BSP, Picea martinezii Patterson, and Picea rubens Sarg. needles have two continuous resin ducts extending from near the base to near the tip. Picea engelmannii Parry ex Engelm., Picea glauca (Moench) Voss, Picea pungens Engelm., Picea mexicana Martinez, and Picea sitchensis (Bong.) Carr. needles have variable numbers of short, intermittent resin ducts or sacs. Within each of these groups, most species could be differentiated based on cross-sectional shape, resin-duct diameter, and resin-duct position. Picea mariana and P. rubens, and P. glauca and P. engelmannii are two pairs with similar needles, but they can be differentiated using linear discriminant analysis based on resin-duct diameter and position in cross section. Paleoecological and paleoclimatological studies may be facilitated by species-level identificatio...

Alkaloids of Picea Breweriana

Alkaloids found in Picea breweriana include hygrine, hygroline, N-methylsedridine and N-methylpelletierine. This represents the first isolation of these alkaloids from the Pinaceae. Euphococcinine, an alkaloid previously found in Picea and Pinus species, is also present. The presence of alkaloids characteristic of two different biosynthetic pathways in P. breweriana highlights the apparent uniqueness of this species.

PICEA WOLFEI, A NEW SPECIES OF PETRIFIED CONE FROM THE MIOCENE OF NORTHWESTERN NEVADA

Several silicified ovulate cones from the late middle Miocene (Barstovian) represent a new species, Picea wolfei Crabtree. This is the second species of Picea for which structurally preserved seed cones are known to be reported from the Tertiary. The cones are 5.0–8.0 cm long and 1.5–2.0 cm at their greatest diameter. Ovuliferous scales are inserted helically around the cone axis and are recurved at their point of divergence. Each scale is broadly obovate to spatulate with a rounded apex and bore two seeds adaxially. The bract subtending the scale is 4.5–7.3 mm long and is fused to the scale for 1.4–2.0 mm. Each bract has an inflated keel‐like base which projects abaxially between the seeds of adjacent scales. The fossil cones superficially resemble those of the extant Picea breweriana, yet differ from them anatomically. The new species also resembles Picea lahontense, a fossil compression from the Miocene Trout Creek Flora of south‐central Oregon, but the different modes of preservation preclude meaningful comparison. Picea diettertiana, the only structurally preserved fossil cone of this genus previously described, is quite dissimilar in that it lacks a sclerotic pith.

Tectonic uplift of a middle Wisconsin marine platform near the Mendocino triple junction, California

An uplifted wave-cut marine platform eroded across bedrock of the Franciscan Complex at Point Delgada, northern California, is overlain by 0.5 to 5 m of wave-worked pea gravel, which is in turn directly overlain by fluvial gravel and silt deposited as alluvial fans. Woody plant debris at the base of the fluvial deposits includes cones of Brewer spruce ( Picea breweriana ), which today are found only at higher elevations and latitudes. Fossil wood debris from this horizon yields a 14C date of 44,800 ± 1,300 yr. The 44,800 yr radiocarbon age for the base of the fluvial deposits establishes an approximate age for the immediately underlying marine gravels and wave-cut platform. We tentatively correlate this terrace with the middle Wisconsin high sea-level stand at −37 m, dated at about 45,000 yr B.P. If this age is correct, the tectonic uplift since middle Wisconsin time has been 44 m, and the average rate of uplift has been at least 1.0 m/1,000 yr. This relatively high rate is probably related to interaction among the Pacific, Gorda, and North American plates at the Mendocino triple junction.

Environmental limits of an endemic spruce, Picea breweriana

Brewer spruce (Picea breweriana Wats.) persists as a relict in protected physiographic situations in southwestern Oregon and northwestern California, where a cool, montane, temperate zone inland from the Pacific Ocean is moderated in summer by maritime air masses. We attempted to uncover the reasons for its survival. We surveyed the species distribution and geologic and floristic associations, then studied effects of environment on growth and survival of two widely distributed species, Pseudotsuga menziesii (Mirb.) Franco and Abies magnifica Murr. var. shastensis Lemm., for a common basis for comparison. The survey included 130 plots along a 250-km transect. Brewer spruce was encountered along 70 km of the transect. Brewer spruce ranked well with other conifers in tolerance to soil moisture stress, cold temperatures, low light, and heavy, deep snow. Although sensitive to high evaporative demand, it appears to compete well with sparse vegetation in infertile or unbalanced soils developed from ultrabasic materials.