scholarly journals Clonal variation in cone and seed production in black and white spruce seed orchards and management implications

1996 ◽  
Vol 72 (5) ◽  
pp. 475-480 ◽  
Author(s):  
Gregory W. Adams ◽  
Hartmut A. Kunze
Keyword(s):  
Seed Production ◽  
Management Practices ◽  
Black Spruce ◽  
White Spruce ◽  
Clonal Variation ◽  
Strong Positive Correlation ◽  
Management Options ◽  
Seed Orchards ◽  
Black And White ◽  
Orchard Management

Variation in cone and seed production across a range of clones in black and white spruce seed orchards was investigated in 1994. The purpose was to develop production information to be used with knowledge of orchard management practices to capture genetic gain more efficiently and improve clonal balance in orchard seedlots. Bulk cone collections were made from ten randomly selected trees for each of 48 clones and 60 clones of white spruce and black spruce, respectively. The average number of cones tree−1 was determined for each clone. Seeds were extracted and average seeds tree−1, seeds cone−1 and seeds g−1 were determined for each clone. Clones were ranked by cone and seed production and significant variation existed between the two ranks. For white spruce, a strong positive correlation was found between number of cones tree−1 and number of seeds, but the same was not found for black spruce, largely because some of the heaviest cone bearing clones produced lower amounts of sound seed. For both species, clones which produced more cones tree−1 tended to produce fewer seeds per cone and the seed was smaller than clones with more moderate levels of cone production. Clonal balance in cone and seed production is discussed with respect to practical orchard management options. Key words: clonal variation, cone and seed production, seed orchard, black spruce, white spruce

scholarly journals The New Brunswick Tree Improvement Council is 20 years old

1997 ◽  
Vol 73 (5) ◽  
pp. 572-577 ◽  
Author(s):  
Dale Simpson ◽  
Kathleen Tosh
Keyword(s):  
New Brunswick ◽  
Seed Production ◽  
Black Spruce ◽  
White Spruce ◽  
Jack Pine ◽  
Tree Improvement ◽  
Team Work ◽  
Ongoing Research ◽  
Seed Orchards ◽  
Stem Straightness

Applied breeding programs in New Brunswick have been coordinated for the past 20 years by the New Brunswick Tree Improvement Council. First-generation programs for black spruce (Picea mariana [Mill.] BSP) and jack pine (Pinus banksiana Lamb.) consisted of seedling seed orchards and open-pollinated family tests, in contrast to those of white spruce (Picea glauca [Moench] Voss) and tamarack (Larix laricina [Du Roi] K.Koch), which were clonal seed orchards and control-pollinated progeny tests. Production from the seed orchards has been regular and heavy. In only 15 years, most reforestation stock was being grown from orchard seed. Early results from black spruce and jack pine realized gain tests indicate increases of 12 to 20% in volume growth by using genetically improved seed. This is double the prediction that was made when the program started. Stem straightness of jack pine trees has been improved by 25%. Second-generation programs of black spruce and jack pine are well underway and production from these orchards is steadily increasing. Indications are that gains from using this seed will be substantial. An ongoing research and development program has contributed to a more effective breeding program, has increased seed production, and has given further insights into wood quality. The success of the Council's program is due to excellent participation and team work by government, university and industrial agencies and their long-term commitment. Key words: seed production, tree improvement, black spruce, white spruce, jack pine, tamarack

Population dynamics of black spruce and white spruce near the arctic tree line in the southern Brooks Range, Alaska

2005 ◽  
Vol 35 (9) ◽  
pp. 2073-2081 ◽  
Author(s):  
Andrea H Lloyd ◽  
Alexis E Wilson ◽  
Christopher L Fastie ◽  
R Matthew Landis
Keyword(s):  
Population Dynamics ◽  
Seed Production ◽  
Matrix Model ◽  
Black Spruce ◽  
White Spruce ◽  
Adult Mortality ◽  
The Arctic ◽  
Tree Line ◽  
Northern Limit ◽  
Fire Intervals

Black spruce (Picea mariana (Mill.) BSP) is the dominant species in interior Alaska but it is largely absent from the arctic tree line. To evaluate the importance of climate and fire as controls over the species distribution, we reconstructed stand history at three sites near its northern limit in Alaska, where it grows with white spruce (Picea glauca (Moench) Voss). We developed a matrix model to explore black spruce population dynamics and response to varying fire intervals. All sites burned in the early 1900s. High recruitment of black spruce occurred for <30 years following the fire, but most current black spruce recruitment is clonal and seed viability is low. White spruce recruitment has been consistently high since the fire, and the majority of seedlings in the stands are white spruce. Despite low recruitment, the matrix model suggests that black spruce populations are nearly stable, largely because of low adult mortality rates. Although black spruce recruitment is stimulated by fire, the model indicates that fire intervals <350 years would destabilize the population, primarily because of slow growth and low seed production. Population dynamics of black spruce at its northern limit in Alaska thus appear to reflect an interaction between fire, which determines the temporal pattern of tree recruitment, and climate, which limits tree growth and, presumably, viable seed production.

Late Wisconsin Vegetational and Climatic History at Kylen Lake, Northeastern Minnesota

1981 ◽  
Vol 16 (3) ◽  
pp. 322-355 ◽  
Author(s):  
H. J. B. Birks
Keyword(s):  
Black Spruce ◽  
Source Area ◽  
White Spruce ◽  
Progressive Increase ◽  
Jack Pine ◽  
Snow Accumulation ◽  
Glacial History ◽  
Black And White ◽  
Pollen Stratigraphy ◽  
Shrub Tundra

AbstractKylen Lake, located within the Toimi drumlin field, is critically positioned in relation to Late Wisconsin glacial advances, for it lies between the areas covered by the Superior and St. Louis glacial lobes between 12,000 and 16,000 yr B.P. The pollen and plant-macrofossil record suggests the presence of open species-rich “tundra barrens” from 13,600 to 15,850 yr B.P. Small changes in percentages of Artemisia pollen between 14,300 and 13,600 yr B.P. appear to be artifacts of pollen-percentage data. Shrub-tundra with dwarf birch, willow, and Rhododendron lapponicum developed between 13,600 and 12,000 yr B.P. Black and white spruce and tamarack then expanded to form a vegetation not dissimilar to that of the modern forest-tundra ecotone of northern Canada. At 10,700 B.P. spruce and jack pine increased to form a mosaic dominated by jack pine and white spruce on dry sites and black spruce, tamarack, and deciduous trees such as elm and ash on moist fertile sites. At 9250 yr B.P. red pine and paper birch became dominant to form a vegetation that may have resembled the dry northern forests of Wisconsin today. The diagram terminates at 8410 ± 85 yr B.P. Climatic interpretation of this vegetational succession suggests a progressive increase in temperature since 14,300 yr B.P. This unidirectional trend in climate contrasts with the glacial history of the area. Hypotheses are presented to explain this lack of correspondence between pollen stratigraphy and glacial history. The preferred hypothesis is that the ice-margin fluctuations were controlled primarily by changes in winter snow accumulation in the source area of the glacier, whereas the vegetation and hence the pollen stratigraphy were controlled by climatic changes in front of the ice margin.

Black and White Spruce Plantings in Minnesota: Container vs Bareroot Stock and Fall vs Spring Planting

1983 ◽  
Vol 59 (4) ◽  
pp. 189-191 ◽  
Author(s):  
A. A. Alm
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Height Growth ◽  
Artificial Regeneration ◽  
Black And White ◽  
Four Seasons ◽  
Spring Planting ◽  
Better Than

Black spruce (Picea mariana (Mill.) B.S.P.) and white spruce (Picea glauca (Moench) Voss) styrob-lock and paperpot and 3-0 and 2-2 seedlings were planted spring and fall. After four seasons of growth the container seedlings had survival and height growth as good or better than the nursery seedlings. There were no differences in performance between the two container systems. The 2-2 stock generally had better survival than the 3-0 stock. Survival of fall-planted stock was equal to or better than that of the spring-planted stock. Key words: white spruce, black spruce, styroplugs, paper pots, seedlings, transplants, artificial regeneration, fall vs spring planting

Survival and growth of black and white spruce seedlings in relation to stock type, site preparation and plantation type in southeastern Manitoba

2000 ◽  
Vol 76 (5) ◽  
pp. 775-782 ◽  
Author(s):  
G. Geoff Wang ◽  
J. Aurea Siemens ◽  
Vince Keenan ◽  
Daniel Philippot
Keyword(s):  
Black Spruce ◽  
White Spruce ◽  
Site Preparation ◽  
Root Collar Diameter ◽  
Black And White ◽  
Significant Difference ◽  
Collar Diameter ◽  
Survival And Growth ◽  
Open Versus ◽  
Root Collar

Differences in survival and growth of black and white spruce seedlings planted on boreal mixedwood sites were tested for stock types (transplant versus container), site preparation (Donaren disc trenching versus no trenching), and plantation types (open versus sheltered) in southeastern Manitoba after eight or nine growing seasons. Mortality of open plantation (32.3%) and container stock (32.5%) were significantly higher than sheltered plantation (23.7%) and transplant stock (22.8%), respectively. Donaren trenching slightly reduced the mortality of black spruce but significantly increased the mortality of white spruce. Seedlings of container stock (110 cm) were significantly shorter than transplant stock (157 cm). Significant difference in height was found between open and sheltered plantations for black spruce but not for white spruce. Root collar diameter of container stock (15.6 mm) was significantly smaller than transplant stock (23.1 mm). Root collar diameter in sheltered plantations was significantly larger than that in open plantations for black spruce but not for white spruce. Black spruce open plantation had significantly smaller volume (97 cm3) compare to black spruce sheltered (210 cm3) and white spruce open (175 cm3) and sheltered (229 cm3) plantations. White spruce open plantations also had smaller volume than white spruce sheltered plantations. Container stock had smaller volume (89 cm3) than transplant stock (267 cm3). For transplant stock, strip plantations had a significantly higher volume (329 cm3) than open plantations (204 cm3). Based on above results, we recommend that (1) transplant stock should be used, (2) sheltered plantation site preparation should be used on boreal mixedwood sites, and (3) Donaren disc-trenching is not necessary for planting white spruce. Key words: silviculture, boreal mixedwood site, plantation

EFFECT OF LEAF AREA ON WHITE CLOVER SEED PRODUCTION

1985 ◽  
Vol 2 ◽  
pp. 25-31
Author(s):  
P.T.P. Clifford
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
White Clover ◽  
Management Practices ◽  
Leaf Size ◽  
Fold Increase ◽  
Yield Potential ◽  
Management Options ◽  
Moisture Management ◽  
Clover Seed

Leaf size is a major determinant of white clover seed yield. A three-fold increase in leaf size halves seed yield. From a survey of commercial crops, an optimum leaf size concept was used to explain the reduction in yield potential for extremes in leaf size. Overgrazing gave small leaves and lowered seed yields. Closing too early gave large leaves and lowered yields. With good management, optimum leaf size was the smallest size possible, consistent with ensuring an adequate bulk for efficient harvesting. A healthy highly-reproductive stolen population has to be developed before closing. Secondly, moisture regulation over the crop season, preventing excess watering to minimise plant exploitation of surplus fertility, reduces the potential for large leaves to develop. Mid-November closing coupled with maintaining soil moisture at about 25% plant available, over flowering, are sound management practices. Amongst cultivars, differences in seed yield potential may also be related to leaf size. In general the larger the mean cultivar leaf size the lower the seed yield. Keywords: Trifolium repens, white clover, seed production, leaf size, soil fertiity, moisture, management options.

Somatic embryo maturation, germination, and soil establishment of plants of black and white spruce (Picea mariana and Picea glauca)

1990 ◽  
Vol 68 (12) ◽  
pp. 2583-2589 ◽  
Author(s):  
S. M. Attree ◽  
T. E. Tautorus ◽  
D. I. Dunstan ◽  
L. C. Fowke
Keyword(s):  
Abscisic Acid ◽  
Somatic Embryo ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Embryo Maturation ◽  
Black And White ◽  
Somatic Embryo Maturation

Somatic embryo maturation, germination, and soil establishment frequencies were compared for two conifer species, white and black spruce (Picea glauca and Picea mariana). The comparison of the two species regenerated and established in soil under the same conditions showed black spruce to be the most responsive. Shorter exposure times to 32 μM abscisic acid were not as effective as maturation on a medium containing 16 μM abscisic acid for 28 days. This gave similar maturation frequencies for the two species (6–8%), and germination frequencies of 64% for white spruce and over 73% for black spruce. Over 1800 black and white spruce plantlets were recovered, and more than 400 were transferred from in vitro to nonsterile conditions. Sixty percent (160) of the black spruce plantlets survived transfer and continued to grow vigorously. By comparison only 18% (29) of the white spruce plantlets survived, and half of these rapidly produced dormant buds and underwent no further shoot growth. White spruce plants that did not produce dormant buds grew vigorously. These results indicate that there are large differences in the ability of these closely related species to respond to plantlet establishment following regeneration from somatic embryos, and that black spruce is highly responsive to micropropagation by this method. Key words: Picea glauca, Picea mariana, somatic embryogenesis, maturation, germination, soil establishment.

Using spatial and temporal patterns of Armillaria root disease to formulate management recommendations for Ontario's black spruce (Piceamariana) seed orchards

1996 ◽  
Vol 26 (2) ◽  
pp. 298-305 ◽  
Author(s):  
J.N. Bruhn ◽  
J.D. Mihail ◽  
T.R. Meyer
Keyword(s):  
Management Practices ◽  
Black Spruce ◽  
Root Disease ◽  
Forest Land ◽  
Spatial And Temporal Patterns ◽  
Seed Orchards ◽  
Disease Mortality ◽  
Armillaria Root Disease ◽  
Management Recommendations ◽  
Logistic Functions

Between 1982 and 1989, 22 black spruce (Piceamariana (Mill.) BSP) seed orchards were established on cleared jack pine (Pinusbanksiana Lamb.) forest land in northwest Ontario. These orchards were located on stressful sites for black spruce to hasten seed production. Mortality caused by Armillariaostoyae (Romagn.) Herink was observed in most of these orchards within 3 years of establishment. This study was initiated to quantitatively describe the temporal progress and spatial patterns of Armillaria root disease mortality in five representative orchards, to determine future operational management implications. In the four orchards where epidemics developed, temporal disease progress was nonlinear and was better described by the monomolecular function than by the Gompertz or logistic functions. Monomolecular rates of disease increase were 0.0062–0.0346. Applying these rates, we estimated that cumulative Armillaria root disease mortality will be 9–41% and 25–79%, at 20 and 50 years after planting, respectively. Armillaria root disease mortality was spatially aggregated in all four orchards. Trees adjacent to Armillaria-killed trees had an increased probability of mortality from Armillaria root disease. Successive epidemics may develop in these orchards; their timing and severity will be affected by orchard management practices. Measures of spruce family performance in these orchards are compromised by the aggregated distributions of different A. ostoyae genets and the root disease they cause.

scholarly journals Integrating Herbicide Programs with Harvest Weed Seed Control and Other Fall Management Practices for the Control of Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri)

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 540-550 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Nicholas E. Korres ◽  
Michael J. Walsh ◽  
Stephen B. Powles
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Cover Crops ◽  
Management Practices ◽  
Palmer Amaranth ◽  
Management Options ◽  
Residual Program ◽  
Amaranth Seed ◽  
Residual Herbicide ◽  
Herbicide Programs

A large-plot field experiment was conducted at Keiser, AR, from fall of 2010 through fall of 2013 to understand to what extent soybean in-crop herbicide programs and postharvest fall management practices impact Palmer amaranth population density and seed production over three growing seasons. The effect of POST-only (glyphosate-only) or PRE followed by (fb) POST (glyphosate or glufosinate) + residual herbicide treatments were evaluated alone and in combination with postharvest management options of soybean residue spreading or soil incorporation, use of cover crops, windrowing with/without burning, and residue removal. Significant differences were observed between fall management practices on Palmer amaranth population density each fall. The use of cover crops and residue collection and removal fb the incorporation of crop residues into soil during the formation of beds were the most effective practices in reducing Palmer amaranth population. In contrast, the effects of fall management practices on Palmer amaranth seed production were inconsistent among years. The inclusion of a PRE herbicide application into the herbicide program significantly reduced Palmer amaranth population density and subsequent seed production each year when compared to the glyphosate-only program. Additionally, the glufosinate-containing residual program was superior to the glyphosate-containing residual program in reducing Palmer amaranth seed production. PRE fb POST herbicides resulted in significant decreases in the Palmer amaranth population density and seed production compared to POST application of glyphosate alone for all fall management practices, including the no-till practice. This study demonstrated that crop residue management such as chaff removal from the field, the use of cover crops, or seed incorporation during bed formation in combination with an effective PRE plus POST residual herbicide program is important for optimizing in-season management of Palmer amaranth and subsequently reducing the population density, which has a profound impact on lessening the risk for herbicide resistance and the consistency and effectiveness of future weed management efforts.

Cone and Seed Yields from Slash Pine Seed Orchards

1994 ◽  
Vol 18 (3) ◽  
pp. 122-127 ◽  
Author(s):  
Gregory L. Powell ◽  
Timothy L. White
Keyword(s):  
Seed Production ◽  
Seed Orchard ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Recording System ◽  
Yield Data ◽  
Seed Orchards ◽  
Orchard Management ◽  
Intensively Managed ◽  
Seed Yields

Abstract The Cooperative Forest Genetics Research Program (CFGRP) initiated a slash pine (Pinus elliottii Engelm. var. elliottii) seed orchard management recording system (SOMRS) in 1985 to quantify cone and seed yields of slash pine orchards in the cooperative program. First, historical data were obtained from CFGRP slash pine seed orchards. Secondly, starting in 1985, cultural treatments and production yield data have been collected annually from 56 slash pine seed orchards located throughout Florida, Georgia, and Alabama. The vast majority of these orchards are intensively managed for seed production including the use of fertilizer, herbicide, and up to 10 applications of insecticide annually. From 1980 through 1990, the average seed yield from mature orchards (orchards greater than 14 yr old) was 25.1 bushels of cones, and 27.3 lb of seed/ac. For pounds per acre, orchards reach 50% and 90% of full production at ages 11 and 18 yr from grafting, respectively. The use of insecticides in slash pine seed orchards approximately doubles orchard yields. The CFGRP slash pine seed orchard management recording system (SOMRS) can aid orchard managers in determining factors that limit or promote seed production. South. J. Appl. For. 18(3):122-127.

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