Taxonomy and origin of present-day morphometric variation in Picea glauca (×engelmannii) seed-cone scales in North America

2006 ◽  
Vol 84 (7) ◽  
pp. 1129-1141 ◽  
Author(s):  
W.L Strong ◽  
L.V. Hills
Keyword(s):  
Rocky Mountains ◽  
Picea Glauca ◽  
White Spruce ◽  
Black Hills ◽  
Picea Engelmannii ◽  
Morphometric Variation ◽  
Engelmann Spruce ◽  
Seed Cone ◽  
Northern United States ◽  
Cone Scale

White spruce ( Picea glauca (Moench) Voss) and Engelmann spruce ( Picea engelmannii Parry ex Engelm.) seed-cones from 676 sites in Canada and the northern United States were analyzed to determine the degree and spatial extent of interspecific hybridization. Fifteen cone-scale variables were analyzed, with percent free-scale and scale shape considered best for differentiating these taxa. The results show that putative Engelmann spruce and their hybrids occur mostly in the vicinity of the Rocky Mountains. Putative white spruce occurs across Canada east of the Rocky Mountains, whereas white × Engelmann hybrids occur eastward to Manitoba and northward to 68° latitude in northwest Canada. To explain the occurrence of the latter taxon hundreds of kilometres from an Engelmann spruce pollen source, it is hypothesized that palaeohybridization occurred during the Wisconsinan glacial period, probably in the southern Montana – Wyoming – Black Hills (South Dakota) region, with the resulting hybrids spreading north and northeastward into interior Canada following the retreat of the Laurentide glacier. White and Engelmann spruce have morphologically distinct cone-scales, whereas their hybrids have intermediate characteristics. An emended species ( Picea albertiana ) and two subspecies (P. albertiana subsp. albertiana and P. albertiana subsp. ogilviei) are proposed to account for morphological intermediates between the parent species.

Tree recruitment from burn edges

2000 ◽  
Vol 30 (8) ◽  
pp. 1264-1274 ◽  
Author(s):  
D F Greene ◽  
E A Johnson
Keyword(s):  
Picea Glauca ◽  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
White Spruce ◽  
Picea Engelmannii ◽  
Larix Laricina ◽  
Tree Recruitment ◽  
Engelmann Spruce ◽  
Large Fires

We developed and tested a wind-dispersal model of tree recruitment into burns from living sources at the fire edge or from small unburned residual stands. The model was also tested on recruitment of serotinous Pinus banksiana Lamb. within a burn. The model assumed that source strength is proportional to basal area density and that an individual (point source) recruitment curve can be expressed as a lognormal distribution. The model made significant predictions of the recruitment curves of Engelmann spruce (Picea engelmannii Parry ex Engelm.), white spruce (Picea glauca (Moench) Voss), and balsam fir (Abies balsamea (L.) Mill.) to distances as great as 2.0 km, although it tended to underpredict Abies and overpredict Picea. The model gave significant prediction of recruitment for jack pine (Pinus banksiana) within burns with seeds derived from aerial seed banks, and of white spruce and tamarck (Larix laricina (Du Roi) K. Koch) up to 100 m from residual stands. By forestry standards, burns are poorly stocked by those species that must obligately recruit from edges. In large fires, adequate stocking by a species such as white spruce that had 5 m2/ha of basal area would be limited to about 70 m from the edge. Small residual stands are expected to supply about half of all the recruits of white spruce or fir at distances exceeding about 800 m from a nominal burn edge.

B Chromosomes in White Spruce

1977 ◽  
Vol 198 (1133) ◽  
pp. 325-344 ◽  
Keyword(s):  
North America ◽  
Picea Glauca ◽  
Constitutive Heterochromatin ◽  
White Spruce ◽  
B Chromosomes ◽  
Experimental Results ◽  
The Other ◽  
Differential Mortality ◽  
X Chromosomes ◽  
Engelmann Spruce

In Picea glauca , the White Spruce, supernumerary, B chromosomes were found in 48 out of 51 North American populations investigated. The B chromosomes are of two kinds. The more common (B1) is metacentric. The other (B2) has a subterminal centromere. Giemsa staining at metaphase shows no trace of constitutive heterochromatin in B chromosomes, yet at interphase the B chromosomes are heteropycnotic. It is argued that the capacity for heterochromatization of the B chromosomes at interphase may be associated with gene inactivation as in the X chromosomes of female mammals. B2 is found in western regions only, i. e. west of the 95th meridian. B1 is found in both western and eastern regions but its frequency varies substantially among populations. In general there is a reduction in B frequency from east to west in both western and eastern regions of North America. Experimental results support the view that such variation is adaptive and, in part at least, caused by the differential mortality of plants with and without B chromosomes in particular environments. Evidence is presented which indicates that B2 was introduced into White Spruce following hybridization with Engelmann Spruce.

scholarly journals Detection of Hybrids in Natural Populations of Picea Glauca and Picea Englemannii

2011 ◽  
Vol 33 ◽  
pp. 119-123 ◽  
Author(s):  
Monia Haselhorst ◽  
C. Buerkle
Keyword(s):  
Rocky Mountains ◽  
Picea Glauca ◽  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Picea Engelmannii ◽  
Forest Trees ◽  
Geographic Mosaic ◽  
Greater Yellowstone ◽  
Central Rocky Mountains ◽  
Genetic Results

The geographic borders between related species are often overlapping and much is unknown about the ecological and evolutionary dynamics between species in these regions. This is particularly true within long-lived forest trees such as conifers. The spruce species Picea glauca and Picea engelmannii were used in this study to elucidate the genetic dimension of their hybridization, as these species are ecologically divergent and are known to hybridize in nature. Opportunities for hybridization occur along elevational gradients where they co-occur, from northwestern Wyoming north through the central Rocky Mountains and British Columbia. This study was concentrated in the Central Rocky Mountains in Wyoming including the Greater Yellowstone Ecosystem. We found remarkable variation of genetic ancestry within and among geographic locations. Our genetic results provide evidence for a previously unrecognized, complex geographic mosaic for the interaction between these two species in this part of North America.

Spruce terpenes: expression and weevil resistance

1999 ◽  
Vol 29 (6) ◽  
pp. 761-767 ◽  
Author(s):  
J R Nault ◽  
J F Manville ◽  
T S Sahota
Keyword(s):  
Picea Glauca ◽  
Picea Engelmannii ◽  
White Pine ◽  
Resistance Level ◽  
Large Variability ◽  
Pissodes Strobi ◽  
Engelmann Spruce ◽  
Highly Correlated ◽  
Resistant Genotypes ◽  
Better Than

White spruce (Picea glauca (Moench) Voss) and Engelmann spruce (Picea engelmannii Parry) parent trees were selected that were rated as highly resistant or highly susceptible to white pine weevil (Pissodes strobi Peck) attack, based upon attack measurements on their open-pollinated progeny. For each parent, levels of terpenes or other volatiles in leaf and bark were highly correlated within ramets and highly variable within progeny. For the ramets, levels of individual terpenes could not be used to predict resistance class because of their large variability. A multivariate model developed using the terpenes showing the greatest differences between resistant classes was found to predict the resistance levels of the original ortets well, with 15 of 16 parent trees correctly predicted using either leaf or bark chemicals. These models failed to predict the resistance level of the open-pollinated progeny. Discriminant analysis was also attempted by dividing the ramet data into independent sets and using each set to predict the other. Again, prediction was no better than chance. We conclude that there is no merit in using terpenes as a selection tool to find resistant genotypes amongst white and Engelmann spruce populations.

Toxicity of two Engelmann spruce (Pinaceae) monoterpene chemotypes from the southern Rocky Mountains to North American spruce beetle (Coleoptera: Scolytidae)

2020 ◽  
Vol 152 (6) ◽  
pp. 790-796
Author(s):  
Thomas Seth Davis
Keyword(s):  
Rocky Mountains ◽  
Picea Engelmannii ◽  
Dendroctonus Rufipennis ◽  
Probability Of Survival ◽  
Southern Rocky Mountains ◽  
Engelmann Spruce ◽  
Adult Body Mass ◽  
Spruce Beetle ◽  
Average Probability ◽  
Logit Function

AbstractEngelmann spruce, Picea engelmannii Parry ex Engelm. (Pinaceae), in the southern Rocky Mountains is composed of two distinct phloem monoterpene chemotypes that differ in relative abundances of multiple monoterpenes, particularly α-pinene and Δ3-carene (hereafter, the “α-pinene chemotype” and the “Δ3-carene chemotype”). Here, relative toxicity of these chemotypes is tested on spruce beetle (Dendroctonus rufipennis Kirby) (Coleoptera: Scolytinae), a phloeophagous herbivore that colonises trees of both types. Synthetic monoterpene blends representing each chemotype were tested across a range of concentrations (0, 10, 50, 100, 200, and 500 µg/L) in the lab, and probability of survival of adult beetles exposed to each blend was modelled using a logit function. Logit curves were solved to determine LC25, LC50, and LC75 of each monoterpene blend. On average, probability of beetle survival was lower when exposed to the Δ3-carene chemotype than when exposed to the α-pinene chemotype. However, both chemotypes were completely lethal to beetles at concentrations exceeding 100 µg/L. Adult body mass did not affect survival probability. It is concluded that spruce phloem chemotypes may differ in their toxicity to spruce beetles, with potential consequences for patterns of host-tree colonisation by spruce beetle.

Population genetic variation, structure, and evolution in Engelmann spruce, white spruce, and their natural hybrid complex in Alberta

2000 ◽  
Vol 78 (6) ◽  
pp. 768-780 ◽  
Author(s):  
Om P Rajora ◽  
Bruce P Dancik
Keyword(s):  
Genetic Variation ◽  
Picea Glauca ◽  
White Spruce ◽  
Natural Hybridization ◽  
Putative Hybrid ◽  
Species Differentiation ◽  
Engelmann Spruce ◽  
Hybrid Complex ◽  
Allozyme Loci ◽  
Putative Hybrids

Genetic variation, structure, and evolution of 12 populations of putative Engelmann spruce (Picea engelmanii Parry), white spruce (Picea glauca (Moench) Voss), and Engelmann - white spruce natural hybrids from the sympatric areas and two populations of white spruce from the allopatric areas in Alberta were examined using 23 allozyme loci coding for 13 enzymes in needles. Although most of the alleles were widespread, unique alleles were found in 9 of the 14 populations. No species-specific allele was observed. However, allele frequency differences were observed between the putative Engelmann and white spruce populations at a number of loci. Frequencies of 13 alleles showed significant correlation with altitude, those of 11 alleles showed correlation with latitude, and those of 3 alleles showed correlation with longitude. On average, 66.2% (99% criterion) of the loci were polymorphic, the number of alleles per locus was 1.88, the number of alleles per polymorphic locus was 2.88, and the observed and expected heterozygosities were 0.063 and 0.184, respectively. Genetic variability of allopatric white spruce, putative Engelmann, sympatric white spruce, and hybrid populations was quite comparable. The mean FST estimate was 0.123 for the total populations. Canonical discriminant functions separated four putative Engelmann spruce populations from the fifth putative Engelmann spruce population and from the allopatric and sympatric white spruce and sympatric putative hybrid populations. A cluster analysis from genetic distances generally separated allopatric and sympatric white spruce populations from the putative Engelmann spruce and hybrid populations. A Wagner tree of the 14 populations produced two main branches; one branch consisting of two allopatric and two sympatric white spruce and one putative hybrid populations, and another branch consisting of the remaining nine spruce populations representing putative Engelmann spruce, putative hybrids, and sympatric white spruce. Putative hybrids showed lower distances to white spruce from the canonical discriminant analysis, whereas they showed lower distances to putative Engelmann spruce from the genetic distance analysis. High allozyme genetic identities between putative Engelmann and white spruce and allelic differentiation related to altitude in Alberta suggest that Engelmann spruce could at best be considered as a subspecies of Picea glauca, with white spruce named as Picea glauca ssp. glauca and Engelmann spruce named as Picea glauca ssp. engelmannii.Key words: Picea glauca, Picea engelmannii, biosystematics, natural hybridization, species differentiation, genetic divergence.

scholarly journals Tree Shelters Improve the Survival and Growth of Planted Engelmann Spruce Seedlings in Southwestern Colorado

2001 ◽  
Vol 16 (3) ◽  
pp. 114-120 ◽  
Author(s):  
Douglass F. Jacobs ◽  
Klaus Steinbeck
Keyword(s):  
Rocky Mountains ◽  
Growing Season ◽  
High Elevation ◽  
Picea Engelmannii ◽  
Control Treatment ◽  
Growth And Survival ◽  
Tree Shelters ◽  
Engelmann Spruce ◽  
Growing Seasons ◽  
Survival And Growth

Abstract Shade-tolerant Engelmann spruce (Picea engelmannii) is a difficult species to reforest successfully in the high-elevation spruce-fir forests of the Rocky Mountains. This study investigated the use of plastic tree shelters as a form of shade protection and a means to improve the growth and survival of planted Engelmann spruce seedlings in southwest Colorado. A total of 1500 seedlings were planted into a 48 ha clearcut site at an average elevation of 3273 m. Treatments included four different colors of tree shelters and a control where seedlings were planted using the traditional shading method. This consisted of shading the seedlings using logging slash, stumps, and vegetation within the site. After two growing seasons, survival was 58% for the control treatment and ranged from 95 to 99% in the lighter three shelter color treatments. The darkest shelter color resulted in 95% mortality after the first growing season. Both height and diameter growth of surviving seedlings were significantly greater in the lightest two shelter color treatments as compared to the control treatment. These results indicate that tree shelters may provide an effective method of improving high-elevation Engelmann spruce reforestation programs. West. J. Appl. For. 16(3):114–120.

SPRUCE CONE INSECTS IN BRITISH COLUMBIA AND THEIR CONTROL

1973 ◽  
Vol 105 (1) ◽  
pp. 113-122 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Black Spruce ◽  
Gall Midge ◽  
White Spruce ◽  
Important Species ◽  
Systemic Insecticides ◽  
Engelmann Spruce ◽  
Cone Axis ◽  
Considerable Loss

AbstractInsects cause considerable loss of seed in white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, P. engelmannii Parry, in British Columbia. The most important species are a maggot, Hylemya anthracina (Cz.), and a seed moth, Laspeyresia youngana (Kit.). Other insects are: a seed chalcid, Megastigmus piceae Roh., a cone axis midge, Dasineura rachiphaga Tripp, a gall midge, D. canadensis Felt, a seed midge, Mayetiola carpophaga Tripp, and a scale-feeding midge. These insects also occur in cones of Sitka spruce, P. sitchensis (Bong.) Carr., and black spruce, P. mariana (Mill.) BSP.The systemic insecticides dimethoate and formothion proved to be effective against these insects when applied as sprays following pollination in mid-June.

Pollen scavenging and rain involvement in the pollination mechanism of interior spruce

1996 ◽  
Vol 74 (1) ◽  
pp. 115-124 ◽  
Author(s):  
C. John Runions ◽  
John N. Owens
Keyword(s):  
Picea Glauca ◽  
Selective Pressure ◽  
Seed Orchard ◽  
Picea Engelmannii ◽  
Pollination Efficiency ◽  
Pollination Mechanism ◽  
Pollination Mechanisms ◽  
Seed Cone ◽  
Interior Spruce ◽  
Pollination Drop

Pollination drops are secreted from the ovules of interior spruce (Picea glauca or Picea engelmannii and their hybrid) as seed cones begin to close at the end of the pollination period. Secreted pollination drops persist within spaces surrounding the micropylar opening in closed seed cones. Saccate pollen floats into the micropyle within the pollination drop. Pollination drops become voluminous enough, within the enclosed spaces, to scavenge pollen adhering to the micropylar arms and other surfaces in proximity with the micropyle. Scavenging of pollen from cone surfaces adjacent to the integuments is sometimes facilitated by rainwater that can float pollen into the opening of the micropyle before cone closure and pollination drop secretion. In practice, periodic, light misting of seed orchard trees during seed cone receptivity might increase pollination efficiency by mimicking rainwater involvement in the pollination mechanism. Rainwater involvement in pollination of some modern conifers may reflect a similar situation in the pollination mechanisms of ancestral conifers. Environments with limited rainfall combined with the requirement for moisture in the pollination mechanism may have provided the selective pressure for evolution of the pollination drop. Keywords: pollination drop, Picea, conifer, sacci.

Sign in / Sign up

Export Citation Format

Share Document