Seed production of Pinus sylvestris after release cutting

2000 ◽  
Vol 30 (6) ◽  
pp. 982-989 ◽  
Author(s):  
Christer Karlsson
Keyword(s):  
Pinus Sylvestris ◽  
Seed Production ◽  
Seed Quality ◽  
Seed Viability ◽  
Tree Height ◽  
Tree Age ◽  
Cone Production ◽  
Crown Length ◽  
Viable Seeds ◽  
Individual Trees

The effects of release cutting on cone, seed production, and seed quality were investigated in 1995-1996 among Scots pine (Pinus sylvestris L.) seed trees in central Sweden. The effects of diameter, height, crown length, and age of trees on cone production were also examined. Cone and seed production were about five times higher in seed trees that had been released for 4 or 5 years, compared with control trees in the unreleased forest. Seed trees released for less than 3 years had about the same level of cone production as the controls. After release, the number of cones increased more in the lower part of the tree crowns than in the uppermost 2 m. The mean 1000-seed weight, seed viability, and number of viable seeds per cone were not significantly different between released and unreleased trees. In 1996, there were about eight times more cones than in 1995, probably because summer temperatures were higher in 1994 than in 1993, the years when the respective flower buds were initiated. Within the investigated range of diameters, 250-430 mm at breast height, a 10-mm increase in diameter was correlated with a 10% increase in mean cone production. However, the variation in cone production between individual trees was considerable. Tree height, length of green crown, and tree age showed no significant correlations with cone production.

Predicting sugar maple (Acer saccharum) discoloured wood characteristics

2013 ◽  
Vol 43 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Sharad Kumar Baral ◽  
Robert Schneider ◽  
David Pothier ◽  
Frank Berninger
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Tree Height ◽  
Tree Age ◽  
Wood Volume ◽  
Nonlinear Mixed Effects Model ◽  
Crown Length ◽  
Crown Characteristics ◽  
The Relationship ◽  
Wood Columns

The presence of wound (strain) initiated discoloured wood columns in the core of sugar maple (Acer saccharum Marshall) stems reduces the proportion of white-coloured wood and, thus, lowers its commercial value. This study aimed to assess the relationship between tree characteristics and the extent and proportion of discoloured wood in sugar maple tree stems. Using 109 trees from three different sites in southern Quebec, we found that the proportion of discoloured wood increased with decreasing sapwood volume and increasing tree age. Younger trees showed a significantly lower proportion of discoloured wood volume. Discoloured wood volume increases disproportionately with tree diameter, while varying among sites. The third important factor affecting the amount of discolored wood was tree vigour as measured by crown characteristics and growth rate changes. A nonlinear mixed-effects model was used to predict discoloured wood taper. Height along the stem was used as a predictor, along with diameter at 1.3 m (DBH), the ratio of live crown length to tree height, and tree height. Although observed injury surface area was positively correlated to discoloured wood volume, injury information did not explain a large share of discoloured wood proportion variation. Overall, older and larger trees with many injuries on less productive sites are likely to have more discoloured wood.

Some Factors Influencing Cone Production on Young Black Spruce in New Brunswick

1981 ◽  
Vol 57 (6) ◽  
pp. 267-269 ◽  
Author(s):  
J. D. Simpson ◽  
G. R. Powell
Keyword(s):  
New Brunswick ◽  
Picea Mariana ◽  
Black Spruce ◽  
Tree Height ◽  
Tree Age ◽  
Cone Production ◽  
Factors Influencing ◽  
Seed Cone ◽  
Pollen Cone

Ten young black spruce (Picea mariana [Mill.] B.S.P.) plantations in northern and central New Brunswick were examined to de termine the influence of aspect, slope, tree age and tree height on pollen-cone and seed-cone production. It was found that a greater proportion of trees growing on southerly aspects produced pollen cones and seed cones than trees growing on northerly aspects. Trees growing on southerly aspects bore 2.5 and 5 times more seed cones and pollen cones, respectively, than trees growing on northerly aspects. Cone production on south-sloping sites was approximately double that on level sites. The number of seed cones was most significantly correlated with tree height. The number of pollen cones was most significantly correlated with number of seed cones.

scholarly journals Effect of botanicals and insecticides seed treatment and containers on seed longevity of black gram under natural ageing conditions

2015 ◽  
Vol 7 (1) ◽  
pp. 328-334 ◽  
Author(s):  
N. Amruta ◽  
G. Sarika ◽  
Umesha Umesha ◽  
J. B. Maruthi ◽  
G. V. Basavaraju
Keyword(s):  
Seed Production ◽  
Seed Treatment ◽  
Seed Quality ◽  
Seed Viability ◽  
Dry Weight ◽  
Management Approach ◽  
Black Gram ◽  
Ambient Conditions ◽  
Emamectin Benzoate ◽  
Production Programme

Good storage is the basic requirement in seed production programme as maintenance of high seed viability and vigour from harvest to planting is of utmost importance in a seed production programme. Therefore, inexpensive, simple and practicable technology to prolong the shelf life of seeds under ambient condition is immensely needed. Hence, an experiment was carried out to study the effect of seed treatment with neem oil, nimbicidin, emamectin benzoate 5 SG, deltamethrin 2.8 EC, novuluron EC on black gram seed quality under ambient conditions. The seeds without any seed treatment were included as control. The treated and untreated seeds were stored in cloth bag and polylined cloth bag. The results revealed that, botanicals and emamectin benzoate seed treatments were significantly superior in controlling the storage insect and maintaining higher seed quality up to 10 months of storage when compared to control. Among the chemicals, the emamectin benzoate 5 SG @ 40 mg kg-1 of seed found better by recording significantly higher germination percentage (80.28), vigour index I (2124) and dry weight of seedlings (43.14 mg) and lower electrical conductivity (0.939 dSm-1) and seed damage (0.00 %) compared to control (78.78%, 2012, 38.90 mg, 0.942 dSm-1, respectively) at the end of 10th month of storage. The emamectin benzoate 5 SG and nimbicidintreated seeds stored in polylined cloth bags were considered as effective seed storage management approach in blackgram.

scholarly journals Biomass functions applicable to oak trees grown in Central-European forestry

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 109-120 ◽  
Author(s):  
E. Cienciala ◽  
J. Apltauer ◽  
Z. Exnerová ◽  
F. Tatarinov
Keyword(s):  
Aboveground Biomass ◽  
Strong Predictor ◽  
Tree Height ◽  
Stem Bark ◽  
Quercus Petraea ◽  
Tree Age ◽  
Central European ◽  
Crown Length ◽  
Oak Trees ◽  
Biomass Functions

This study describes the parameterization of biomass functions applicable to oak (<I>Quercus robur, Quercus petraea</I>) trees grown in the conditions of Central-European forestry. It is based on destructive measurements of 51 grown trees sampled from 6 sites in different regions of the Czech Republic important for oak forest management. The samples covered trees of breast height diameter (<I>D</I>) ranging from 6 to 59 cm, tree height (<I>H</I>) from 6 to 32 m and age between 12 and 152 years. The parameterization was performed for total aboveground biomass and its individual components. The two basic levels of biomass functions utilized <I>D</I> either as a single independent variable or in combination with <I>H</I>. The functions of the third level represented the best function for each biomass component with the optimal combination of available independent variables, which included <I>D, H</I>, crown length (<I>CL</I>), crown width (<I>CW</I>), crown ratio (<I>CR = CL/H</I>), tree age and site altitude. <I>D</I> was found to be a particularly strong predictor for total tree aboveground biomass. <I>H</I> was found to always improve the fit, particularly for the individual components of aboveground biomass. The contribution of <I>CW</I> was minor, but significant for all biomass components, whereas <I>CL</I> and <I>CR</I> were found useful for the components of stem and living branches, respectively. Finally, the remaining variables tree age and altitude were each justified only for one component function, namely living branch biomass and stem bark, respectively. The study also compares the fitted functions with other available references applicable to oak trees.

Factors Limiting the Recruitment of Eucalyptus salmonophloia in Remnant Woodlands .I. Pattern of Flowering, Seed Production and Seed Fall

1994 ◽  
Vol 42 (5) ◽  
pp. 531 ◽  
Author(s):  
CJ Yates ◽  
RJ Hobbs ◽  
RW Bell
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Seed Viability ◽  
Fragmented Landscape ◽  
Viable Seed ◽  
Seed Fall ◽  
Individual Trees ◽  
Western Australian ◽  
Remnant Population ◽  
Conservation Of Biodiversity

Woodlands dominated by Eucalyptus salmonophloia F. Muell. occur throughout the fragmented landscape of the Western Australian wheatbelt. In most of these remnant woodlands, there is no regeneration of E. salmonophloia and this has become a concern for the conservation of biodiversity in the region. This study examined seed production, seed viability and pattern of seed fall in four remnant populations of E. salmonophloia in the central wheatbelt of Western Australia, to determine whether these factors are limiting recruitment. Surveys of flowering, seed production and seed fall were conducted over a two-year-period which included three potential flowering seasons. Individual trees flowered once over this period and the intensity of flowering and the proportion of flowers which set seed varied greatly between remnants. Seed from up to two consecutive flowering seasons was stored in the canopy, thus, E. salmonophloia formed substantial canopy seed stores. Seeds were released from this store throughout the year and seed fall showed only a weak winter decline. The viability of seeds released from the canopy store in each remnant population was high. These results indicate that the availability of viable seed is unlikely to be responsible for the lack of E. salmonophloia recruitment in remnant woodlands.

Age and size effects on first cone production among white spruce trees

2020 ◽  
Vol 50 (5) ◽  
pp. 519-522
Author(s):  
Michael T. Bronson
Keyword(s):  
Picea Glauca ◽  
Tree Height ◽  
White Spruce ◽  
Tree Age ◽  
Population Changes ◽  
Growth Rings ◽  
Reproductive Maturity ◽  
Cone Production ◽  
Competition For Light ◽  
Effect Of Age

The onset of lifetime reproduction is central to processes of plant adaptation and population changes. The relative contributions of size and age to the onset of reproduction are important to predicting that key event in individuals. To estimate respective size and age effects on first reproduction in a conifer, I observed white spruce (Picea glauca (Moench) Voss) trees in forest stands in Alaska, United States, over ranges of cumulative growth rates. Age was estimated by counting annular growth rings, size was indicated by tree height, and reproductive status was indicated by seed cones. Multiple logistic regression showed the relative contributions of tree height and age, adjusted for each other, to statistical predictions of reproductive maturity. Trees selected for having little competition for light first produced cones at heights between 1 and 5 m with little additional effect of age. Tree height contributed approximately 50% to regression predictions of reproductive maturity. In contrast, tree age contributed ≤1.5% and bore little relation to reproductive maturity other than as a component of growth rate. This is among the first reports to partial the effect sizes of tree size and age on the commencement of lifetime reproduction in a conifer.

Studies in the ecology of Nothofagus cunninghamii Oerst. II. Phenology

1973 ◽  
Vol 21 (1) ◽  
pp. 79 ◽  
Author(s):  
TM Howard
Keyword(s):  
Seed Production ◽  
Seed Viability ◽  
Tree Age ◽  
Average Annual Rate ◽  
Continuous Growth ◽  
Apical Bud ◽  
Lateral Buds ◽  
Adult Trees ◽  
Rate Of Decay ◽  
Hills Area

After germination, seedling growth of Nothofagus cunninghamii results from spring flushing of lateral buds, combined at 4-5 years of age with continuous growth from an apical bud during summer. Adult trees all flush from lateral buds in spring. In addition occasional sporadic flushes occur in autumn, but decrease in frequency with increase in altitude. Within the first 4-5 years of life of Victorian N. cunninghamii seedlings, epicormic burl development with the proliferation of dormant buds commences. This epicormic burl is poorly developed on trees in the Surrey Hills area of northwestern Tasmania. It is suggested that burl formation may have been selected by more constant burning in Victoria, where trees able to coppice after fire have both higher growth rate and earlier seed production than seed-produced plants. Flowering of N. cunninghamii in Victoria is annual and seed production is generally high. Seed viability increases with tree age, and decreases with stand altitude. The average viability at 3300 ft is 45-50%, and production may be as high as 11 x 106 seeds per acre. The effective longevity in the field is 8-9 months, though dry stored seed at room temperature may germinate, with some viability loss, after 2½ years. The fall of litter in an N. cunninghamii forest is 6.5 tonnes per hectare per year, and the average annual rate of decay is 0.42. N. cunninghamii leaves live for just over 3 years, falling in autumn after the spring growth has matured.

Factors affecting the relationship between sapwood area and leaf area of balsam fir

1992 ◽  
Vol 22 (11) ◽  
pp. 1684-1693 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Basal Area ◽  
Tree Height ◽  
Balsam Fir ◽  
Tree Age ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Crown Length ◽  
Basal Area Growth ◽  
Area Growth

The ratio between projected leaf area (LA) and cross-sectional sapwood area (SA) of dominant and codominant balsam fir trees (Abiesbalsamea (L.) Mill.) was determined in 24 forest stands across the province of Quebec. Various physical factors proposed in the Whitehead hydraulic model, and some of the easily measured surrogates of these factors, were tested for their influence on LA:SA ratios. Average growing season vapor pressure deficit, temperature, precipitation, and stand drainage class did not significantly influence LA:SA ratios. On the other hand, LA:SA ratios were positively influenced by sapwood permeability (k), tree height, and crown length. As suggested by the model, there was a positive correlation between sapwood permeability and LA:SA ratio and a negative correlation between tree height or crown length and LA/(SA k). Increases in sapwood permeability with tree age were associated with longer tracheids having larger lumen diameters. Of the various empirical factors tested, only site quality, 5-year basal area growth, and age had a significant influence on LA:SA ratios. Sapwood cross-sectional area at breast height by itself was a reasonable linear predictor of LA for all stands (LA = −0.158 + 0.709 SABH, R2 = 0.75). Using the variables that were previously determined to influence LA:SA ratios, stepwise regressions revealed that only crown length and 5-year basal area growth significantly improved linear predictions of LA based on sapwood area. However, the increase in R2 was relatively modest, i.e., 0.83 for all three independent variables versus 0.75 for SA alone. The results from this study will be useful in integrating physiologically based measurements, such as growth efficiency, into standard forest inventory practices for balsam fir and thus could be beneficial in developing new silvicultural strategies for protecting Quebec's forest resource.

Seed and pollen production after stem injections of gibberellin A4/7 in field-grown seed orchards of Pinus sylvestris

1998 ◽  
Vol 28 (3) ◽  
pp. 340-346 ◽  
Author(s):  
Urban Eriksson ◽  
Gunnar Jansson ◽  
Curt Almqvist
Keyword(s):  
Pinus Sylvestris ◽  
Seed Production ◽  
Seed Weight ◽  
Floral Induction ◽  
Pollen Production ◽  
Seed Orchards ◽  
Cone Production ◽  
Empty Seeds ◽  
Filled Seeds

The effects of stem injections of gibberellin A4/7 (GA4/7) were studied in two experiments conducted in two different field-grown seed orchards of Pinus sylvestris L. Both experiments were carried out during years with favourable conditions for floral induction, i.e., higher temperatures and less precipitation than average years. In experiment 1, cone production and the number of filled seeds per graft increased significantly, the latter by about 60% compared with the control. Filled seeds per graft increased in experiment 2 as well, although the increase was not statistically significant. In both experiments, GA4/7 treatment significantly reduced the 1000-seed weight but did not significantly affect the number of filled and empty seeds per cone. In both experiments, grafts stimulated to increase seed production tended to produce smaller cones. In experiment 2, pollen production was significantly increased after stem injections of GA4/7. The increase above the control was about 90%. There was a tendency for stem injections of GA4/7, which were intended to increase seed production, to reduce pollen production. Clonal effects were significant for all variables tested in the study. No damage to the treated grafts were observed that could be attributed to the treatment. The use of stem injections of GA4/7 as an operational means in seed orchards of P. sylvestris is therefore recommended.

scholarly journals Selection potential of tree populations for forest reclamation complexes

2020 ◽  
pp. 56-74
Author(s):  
А.В. Семенютина ◽  
С.Н. Крючков ◽  
А.Ш. Хужахметова
Keyword(s):  
Pinus Sylvestris ◽  
Seed Production ◽  
Quercus Robur ◽  
Structural Characteristics ◽  
Practical Interest ◽  
Biological Indicators ◽  
Salt Resistance ◽  
Forest Reclamation ◽  
Growing Conditions ◽  
Individual Trees

Повышение устойчивости и долговечности защитных лесных насаждений возможно воздействием целого комплекса приемов и мероприятий по семеноведению, семеноводству, размножению и выращиванию селекционно улучшенного посадочного материала и оптимизации фитосанитарной обстановки. К каждому составляющему комплекса планируются принципиально новые подходы и пути решения. О ценных свойствах популяций отобранного генофонда деревьев в аридных условиях (юг европейской территории России) можно судить по факту достижения ими предельного (50-70 лет) возраста при неоднократном воздействии жестких засух, сильных морозов, инвазий вредителей и болезней и др. Объектами исследований являлись естественные и искусственные популяции Quercus roburL., Pinus sylvestris L., P. pallasiana D.Don, P. nigraArnold, P. banksiana Lamb., P. ponderosa Dougl. на юге европейской территории России (Волгоградская, Астраханская области, Республика Калмыкия). Исследования базируются на методологии включающей мониторинг, выявление критериев отбора с учетом комплексных исследований (засухо-, морозо-, солеустойчивость, устойчивость к вредителям и болезням). Дана комплексная оценка различных экотипов Quercus robur L. по потомству (25-летние растения в клоновом архиве). В лесорастительных условиях региона исследований перспективными, по лесоводственным и биологическим показателям, показали себя популяции Quercus robur L. из следующих областей: Воронежская, Витебская, Белгородская. Приведены достоверные различия между экотипами, рекомендуемые для селекционного семеноводства. Выявлены различия между фенологическими формами по длительности ростовых процессов, ритмике развития, таксационным показателям. Выявлены представители рода Pinus (Pinus sylvestris L., P. pallasianaD.Don, P. ponderosa Dougl.) представляющие практический интерес для защитного лесоразведения в южных регионах. В России значительная часть (65%) искусственных насаждений представлена культурами P. sylvestris L. Из многообразия почвенных экотипов, для агролесомелиорации представляет интерес экотип, сформировавшийся на меловых обнажениях. В связи с чем он применяется в противоэрозионных насаждениях в Среднем и Нижнем Поволжье. Некоторые характеристики урожая семян отдельных деревьев имели большие вариации и отличались низкими показателями вследствие исключительно засушливого периода наблюдений. В результате инвентаризации естественных и искусственных насаждений изучены морфологические и структурные характеристики и выделены перспективные популяции для селекционных целей при создании агролесомелиоративных комплексов. Получены теоретические и экспериментальные материалы на уровне географической, экологической, локальной популяции и данные по комплексной устойчивости сортообразцов. Increasing the stability and durability of protective forest stands can be influenced by a whole range of techniques and measures for seed science, seed production, propagation and cultivation of selectively improved planting material and optimization of the phytosanitary situation. Fundamentally new approaches and solutions are planned for each component of the complex. The valuable properties of the populations of the selected tree gene pool in arid conditions (South of the European territory of Russia) can be judged by the fact that they reach the maximum age (50-70 years) under repeated exposure to severe droughts, severe frosts, pest infestations and diseases, etc. The objects of research were natural and artificial populations of Quercus roburL., Pinus sylvestris L., P. pallasiana D. Don, P. nigraArnold, P. banksiana Lamb., P. ponderosa Dougl. in the South of the European territory of Russia (Volgograd, Astrakhan regions, Republic of Kalmykia). The research is based on a methodology that includes monitoring, identification of selection criteria taking into account complex studies (drought, frost, salt resistance, pest and disease resistance). A comprehensive assessment of various ecotypes of Quercus robur L. by offspring (25-year-old plants in the clone archive) is given. In the forest-growing conditions of the research region, the populations of Quercus robur l have shown themselves to be promising in terms of forestry and biological indicators. from the following areas: Voronezh, Vitebsk, And Belgorod Regions. There are significant differences between ecotypes recommended for selective seed production. Differences between phenological forms in the duration of growth processes, the rhythm of development, and taxational indicators are revealed. Representatives of the genus Pinus (Pinus sylvestris L., P. pallasianaD. Don, P. ponderosa Dougl.) of practical interest for protective afforestation in the southern regions have been identified. In Russia, a significant part (65%) of artificial plantings is represented by P. sylvestris L. crops. From the variety of soil ecotypes, the ecotype formed on Cretaceous outcrops is of interest for agroforestry. In this connection, it is used in anti-erosion plantings in the Middle and Lower Volga region. Some characteristics of the seed yield of individual trees had large variations and were characterized by low indicators due to an exceptionally dry observation period. As a result of the inventory of natural and artificial plantings, morphological and structural characteristics were studied and promising populations were identified for breeding purposes when creating agroforestry complexes. Theoretical and experimental materials were obtained at the level of geographical, ecological, and local populations, as well as data on the complex stability of cultivars.

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