Crown Branches Research Articles

Ethylene Action Inhibition Improves Adventitious Root Induction in Adult Chestnut Tissues.

Phase change refers to the process of maturation and transition from the juvenile to the adult stage. In response to this shift, certain species like chestnut lose the ability to form adventitious roots, thereby hindering the successful micropropagation of adult plants. While auxin is the main hormone involved in adventitious root formation, other hormones, such as ethylene, are also thought to play a role in its induction and development. In this study, experiments were carried out to determine the effects of ethylene on the induction and growth of adventitious roots. The analysis was performed in two types of chestnut microshoots derived from the same tree, a juvenile-like line with a high rooting ability derived from basal shoots (P2BS) and a line derived from crown branches (P2CR) with low rooting responses. By means of the application of compounds to modify ethylene content or inhibit its signalling, the potential involvement of this hormone in the induction of adventitious roots was analysed. Our results show that ethylene can modify the rooting competence of mature shoots, while the response in juvenile material was barely affected. To further characterise the molecular reasons underlying this maturation-derived shift in behaviour, specific gene expression analyses were developed. The findings suggest that several mechanisms, including ethylene signalling, auxin transport and epigenetic modifications, relate to the modulation of the rooting ability of mature chestnut microshoots and their recalcitrant behaviour.

Canopy Structural Changes in Black Pine Trees Affected by Pine Processionary Moth Using Drone-Derived Data

Pine species are a key social and economic component in Mediterranean ecosystems, where insect defoliations can have far-reaching consequences. This study aims to quantify the impact of pine processionary moth (PPM) on canopy structures, examining its evolution over time at the individual tree level using high-density drone LiDAR-derived point clouds. Focusing on 33 individuals of black pine (Pinus nigra)—a species highly susceptible to PPM defoliation in the Mediterranean environment—bitemporal LiDAR scans were conducted to capture the onset and end of the major PPM feeding period in winter. Canopy crown delineation performed manually was compared with LiDAR-based methods. Canopy metrics from point clouds were computed for trees exhibiting contrasting levels of defoliation. The structural differences between non-defoliated and defoliated trees were assessed by employing parametric statistical comparisons, including analysis of variance along with post hoc tests. Our analysis aimed to distinguish structural changes resulting from PPM defoliation during the winter feeding period. Outcomes revealed substantive alterations in canopy cover, with an average reduction of 22.92% in the leaf area index for defoliated trees, accompanied by a significant increase in the number of returns in lower tree crown branches. Evident variations in canopy density were observed throughout the feeding period, enabling the identification of two to three change classes using LiDAR-derived canopy density metrics. Manual and LiDAR-based crown delineations exhibited minimal differences in computed canopy LiDAR metrics, showcasing the potential of LiDAR delineations for broader applications. PPM infestations induced noteworthy modifications in canopy morphology, affecting key structural parameters. Drone LiDAR data emerged as a comprehensive tool for quantifying these transformations. This study underscores the significance of remote sensing approaches in monitoring insect disturbances and their impacts on forest ecosystems.

Tree structure instead of microclimatic zones determines differences in vascular epiphyte assemblages between forest and pasture

Land cover change threatens biodiversity by reducing species richness, altering species composition, and favouring generalist species. Pasture creation can promote the loss of original species, although this loss can be mitigated by maintaining scattered trees to reduce their structural differences with forests and thus retaining a portion of regional epiphyte diversity. We explore the negative effects of land cover change and potential factors promoting similarity of epiphyte assemblages between forests and pastures. We hypothesize that pasture epiphyte assemblages are characterized by low species richness and are dominated by xerotolerant and generalist species, with a species composition nested from the forest community, indicating a degree of overlap. We hypothesize that two main factors drive the similarity between forest and pasture epiphyte assemblages: “structural dependence”, whereby trees host similar species on their crowns and trunks independent of habitat, and “microclimatic dependence”, where pasture and forest trees are more similar in areas with comparable microclimatic conditions. We found lower species richness and higher abundance of generalist species in the pasture than in the forest, with differing species composition. However, there was still a significant overlap in species composition between the two habitats, indicating that the epiphyte assemblages in the pasture were nested from the forest assemblages. Pasture and forest trees shared more epiphyte species between crown and trunk zones rather than between shaded and sunlight-exposed zones. Hence, the similarity of vascular epiphyte assemblages between habitats is partially driven by structural factors, where certain epiphyte species preferentially occur in specific tree zones regardless of the microclimate or habitat. Considering these findings, we recommend maintaining and planting scattered trees in pastures to enhance structural complexity (e.g., longer trunks and multiple crown branching), which can foster a proportion of the vascular species from forested areas, thus maintaining the similarity in vascular epiphyte assemblages between habitats.

Ectopic cambia: Connections between natural and experimental vascular mutants.

One of the most remarkable innovations in the evolution of vascular plants is secondary growth: the developmental process by which plants grow thicker. The textbook illustration of secondary growth--a core of secondary xylem surrounded by a sheath of secondary phloem--is generated through a cylindrical meristem called the vascular cambium (Fig. 1A). This modality is conserved across thousands of species, providing mechanical support for ever-elongating shoots, and a regenerative source of vascular tissues to feed the ever-expanding crown of branches and leaves This article is protected by copyright. All rights reserved.

Produktivitas Kopi Arabika (Coffea arabica Linden.) pada Penaung Berbeda di Hutan Lindung Desa Sukalaksana Kabupaten Garut

The protected forest area managed by Perum Perhutani in Sukalaksana village is dominated by pine trees (Pinus merkusii) and rasamala trees (Altingia excelsa). Coffee farmers in Sukalaksana village grow arabica coffee using an agroforestry system under pine and rasamala stands within the framework of joint forest management. So that the arabica coffee commodity can have optimal economic value, coffee farmers in Sukalaksana village need to observe the productivity of arabica coffee plants. The research location is in the protected forest area of Sukalaksana village, Talegong district, Garut Regency. The object of observation was the soil in coffee plantations, Timtim varieties of arabica coffee plants, planted using an agroforestry system with rasamala trees and pine trees as shade. Data were analyzed descriptively using an uncorrelated t-test and linear regression analysis. Descriptively, there is no difference in the fertility level of coffee planting soil on land shaded by rasamala and land shaded by pine. The productivity of coffee plants under the rasamala shade is higher than that of coffee plants under the pine shade. This is caused by significant differences in the branch-free bole height of shade trees. The rasamala shade has its first crown branch, which is higher than the pine shade.

Spatio-temporal analysis of strawberry architecture: insights into the control of branching and inflorescence complexity.

Plant architecture plays a major role in flowering and therefore in crop yield. Attempts to visualize and analyse strawberry plant architecture have been few to date. Here, we developed open-source software combining two- and three-dimensional representations of plant development over time along with statistical methods to explore the variability in spatio-temporal development of plant architecture in cultivated strawberry. We applied this software to six seasonal strawberry varieties whose plants were exhaustively described monthly at the node scale. Results showed that the architectural pattern of the strawberry plant is characterized by a decrease of the module complexity between the zeroth-order module (primary crown) and higher-order modules (lateral branch crowns and extension crowns). Furthermore, for each variety, we could identify traits with a central role in determining yield, such as date of appearance and number of branches. By modeling the spatial organization of axillary meristem fate on the zeroth-order module using a hidden hybrid Markov/semi-Markov mathematical model, we further identified three zones with different probabilities of production of branch crowns, dormant buds, or stolons. This open-source software will be of value to the scientific community and breeders in studying the influence of environmental and genetic cues on strawberry architecture and yield.

Comparison of field performance and fruit quality among newly released Italian June-bearing strawberry cultivars

The aim of this study was to compare newly released June-bearing strawberry cultivars (?Quicky?, ?Sandra?, ?Lofty?, ?Nadja? and ?Aprica?) in terms of their phenology, vegetative growth, productivity and fruit quality to identify their potential for wider cultivation. A field study was conducted in a strawberry plantation established in July 2020 in double rows on beds covered with black polyethylene foil (Sid, Serbia). The cultivars were evaluated in 2021-2022 for their flowering and ripening time, productivity, plant growth, biometrical and nutritional fruit traits (soluble solids content - SSC, total acids - TAs, vitamin C, total anthocyanins - TACY, total phenolics - TPC and total antioxidant capacity - TAC). The cultivar ?Quicky? started to ripen earliest, while ?Aprica? was the latest in both experimental years. The number of branch crowns per plant was significantly higher in ?Sandra? and ?Lofty?, whereby ?Sandra? had also the highest number of leaves per rosette (41.5) in comparison with the other tested cultivars. The cultivar ?Aprica? was superior in terms of productivity (1061 g/plant and 4.67 kg/m2), fruit weight (29.9 g) and fruit shape index (1.15). Contrary to this, ?Nadja? was the least productive cultivar (608 g/plant and 2.68 kg/m2). The cultivars ?Lofty? and ?Sandra? showed the highest SSC values and were also characterized by a considerably high level of TPC (1.29 mg GAE eq g-1 FW) and TACY (24.4 mg pg-3-g eq 100 g-1 FW), respectively. Variability among the tested cultivars could serve as an important criterion for the selection of new high-performing cultivars for a given growing region.

From flowering to foliage: Accelerometers track tree sway to provide high-resolution insights into tree phenology

Trees are bioindicators of global climate change and regional urbanization, but available monitoring tools are ineffective for fine-scale observation of many species. Using six accelerometers mounted on two urban ash trees (Fraxinus americana), we looked at high-frequency tree vibrations, or change in periodicity of tree sway as a proxy for mass changes, to infer seasonal patterns of flowering and foliage (phenophases). We compared accelerometer-estimated phenophases to those derived from digital repeat photography using Green Chromatic Coordinates (GCC) and visual observation of phenophases defined by the USA National Phenology Network (NPN). We also drew comparisons between two commercial accelerometers and assessed how placement height influenced the ability to extract seasonal transition dates. Most notably, tree sway data showed a greenness signal in an urban environment and produced a clear flowering time-series and peak flowering signal (PF), marking the first observations of a flower phenophase using accelerometer data. Estimated start of spring (SOS) from accelerometers and time-lapse GCC were more similar than start of autumn (SOA); accelerometers lagged behind the time-lapse camera dates by three and four days for SOS and 13 and 14 days for SOA for each tree. Estimates for SOS and SOA from accelerometers and time-lapse cameras aligned closely with different NPN phenophases. The two commercial accelerometers produced similar season onset: a difference of 2.4 to 3.8 days for SOS, 2.1 days for SOA, and 0.5 to 2.0 days for PF. Accelerometers placed at the main crown branch point versus higher in the canopy showed a difference of 0.2 to 4.9 days for SOS and -1.5 to 1.7 days for PF. Our results suggest accelerometers present a novel opportunity to objectively monitor reproductive tree biology and fill gaps in phenology observations. Furthermore, widely available accelerometers show promise for scaling up from individual trees to the landscape level to aid forest management and assessing climate change impacts to tree phenology.

Natural Variation in the Control of Flowering and Shoot Architecture in Diploid Fragaria Species.

In perennial fruit and berry crops of the Rosaceae family, flower initiation occurs in late summer or autumn after downregulation of a strong repressor TERMINAL FLOWER1 (TFL1), and flowering and fruiting takes place the following growing season. Rosaceous fruit trees typically form two types of axillary shoots, short flower-bearing shoots called spurs and long shoots that are, respectively, analogous to branch crowns and stolons in strawberry. However, regulation of flowering and shoot architecture differs between species, and environmental and endogenous controlling mechanisms have just started to emerge. In woodland strawberry (Fragaria vesca L.), long days maintain vegetative meristems and promote stolon formation by activating TFL1 and GIBBERELLIN 20-OXIDASE4 (GA20ox4), respectively, while silencing of these factors by short days and cool temperatures induces flowering and branch crown formation. We characterized flowering responses of 14 accessions of seven diploid Fragaria species native to diverse habitats in the northern hemisphere and selected two species with contrasting environmental responses, Fragaria bucharica Losinsk. and Fragaria nilgerrensis Schlecht. ex J. Gay for detailed studies together with Fragaria vesca. Similar to F. vesca, short days at 18°C promoted flowering in F. bucharica, and the species was induced to flower regardless of photoperiod at 11°C after silencing of TFL1. F. nilgerrensis maintained higher TFL1 expression level and likely required cooler temperatures or longer exposure to inductive treatments to flower. We also found that high expression of GA20ox4 was associated with stolon formation in all three species, and its downregulation by short days and cool temperature coincided with branch crown formation in F. vesca and F. nilgerrensis, although the latter did not flower. F. bucharica, in contrast, rarely formed branch crowns, regardless of flowering or GA20ox4 expression level. Our findings highlighted diploid Fragaria species as rich sources of genetic variation controlling flowering and plant architecture, with potential applications in breeding of Rosaceous crops.

Microhabitat selection by overwintering alder bark beetles (Coleoptera: Curculionidae: Scolytinae) on red alder (Betulaceae)

Abstract The alder bark beetle, Alniphagus aspericollis (LeConte), is known to overwinter as larvae and adults in the main stems of red alder, Alnus rubra (Bongard). Observations of adult alder bark beetles in the branch and bud nodes of planted saplings during the winter led to the hypothesis that these microhabitats represent alternative overwintering sites for the beetle in mature trees. To test this hypothesis, we surveyed crown branches at three coastal British Columbia locations, sampling three trees in 2003 and 2004 and three additional trees (nine branches per tree) in 2018–2019. Adult beetles were found overwintering inside sites excavated in the branch and bud nodes throughout the crowns of mature trees. Branch type, defined by growth class, and tree affected the overall distribution and likelihood of overwintering site occupancy among the three trees sampled intensively in 2018–2019, whereas overwintering site age (old versus new (current year)) affected the frequency of site occupancy across all six trees. We suggest that overwintering in tree crowns evolved from late-summer maturation feeding in new shoots and that the majority of beetles abandon terminal shoots as temperatures fall, moving deeper into the crown to overwinter preferentially in older branch tissues that offer greater thermal protection.

Tree Health Assessment of Lauraceae Collections in Bogor Botanic Gardens using Forest Health Monitoring Method

Bogor Botanic Gardens (BBG) is an ex-situ plant conservation area with thousands of plant collections. The trees of the Lauraceae in BBG experienced the highest number of deaths among other families. However most of them were categorized as young planting years (0-15 years). A tree health monitoring in the Lauraceae needs to be conducted to provide an overview, trend, and value of the level of damage. Forest Health Monitoring (FHM) method was carried out on two plots consisting of 149 trees. FHM can identify the types and levels of damage through monitoring and recording a series of tree damage. The results showed that among 149 trees, with 103 healthy, 9 lightly damaged, 10 moderately damaged, 15 heavily damaged, and 12 dead. The damage was primarily found in the stem (63 trees), the crown branch (51 trees), and the roots (13 trees). The severity of the damage was mainly at a mild level (0-19%). The cause of the damage is discussed. Further observations and frequent monitoring of the health of the Lauraceae need to be conducted by management to reduce the number of dead collections of the family. Keywords: botanic gardens, Forest Health Monitoring, lauraceae, tree health

Woodland strawberry axillary bud fate is dictated by a crosstalk of environmental and endogenous factors.

Plant architecture is defined by fates and positions of meristematic tissues and has direct consequences on yield potential and environmental adaptation of the plant. In strawberries (Fragaria vesca L. and F. × ananassa Duch.), shoot apical meristems can remain vegetative or differentiate into a terminal inflorescence meristem. Strawberry axillary buds (AXBs) are located in leaf axils and can either remain dormant or follow one of the two possible developmental fates. AXBs can either develop into stolons needed for clonal reproduction or into branch crowns (BCs) that can bear their own terminal inflorescences under favorable conditions. Although AXB fate has direct consequences on yield potential and vegetative propagation of strawberries, the regulation of AXB fate has so far remained obscure. We subjected a number of woodland strawberry (F. vesca L.) natural accessions and transgenic genotypes to different environmental conditions and growth regulator treatments to demonstrate that strawberry AXB fate is regulated either by environmental or endogenous factors, depending on the AXB position on the plant. We confirm that the F. vesca GIBBERELLIN20-oxidase4 (FvGA20ox4) gene is indispensable for stolon development and under tight environmental regulation. Moreover, our data show that apical dominance inhibits the outgrowth of the youngest AXB as BCs, although the effect of apical dominance can be overrun by the activity of FvGA20ox4. Finally, we demonstrate that the FvGA20ox4 is photoperiodically regulated via FvSOC1 (F. vesca SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1) at 18°C, but at higher temperature of 22°C an unidentified FvSOC1-independent pathway promotes stolon development.

GRAS transcription factor LOSS OF AXILLARY MERISTEMS is essential for stamen and runner formation in wild strawberry.

Axillary bud development is a major factor that impacts plant architecture. A runner is an elongated shoot that develops from axillary bud and is frequently used for clonal propagation of strawberry. However, the genetic control underlying runner production is largely unknown. Here, we identified and characterized loss of axillary meristems (lam), an ethyl methanesulfonate-induced mutant of the diploid woodland strawberry (Fragaria vesca) that lacked stamens in flowers and had reduced numbers of branch crowns and runners. The reduced branch crown and runner phenotypes were caused by a failure of axillary meristem initiation. The causative mutation of lam was located in FvH4_3g41310, which encodes a GRAS transcription factor, and was validated by a complementation test. lamCR mutants generated by CRISPR/Cas9 produced flowers without stamens and had fewer runners than the wild-type. LAM was broadly expressed in meristematic tissues. Gibberellic acid (GA) application induced runner outgrowth from the remaining buds in lam, but failed to do so at the empty axils of lam. In contrast, treatment with the GA biosynthesis inhibitor paclobutrazol converted the runners into branch crowns. Moreover, genetic studies indicated that lam is epistatic to suppressor of runnerless (srl), a mutant of FveRGA1 in the GA pathway, during runner formation. Our results demonstrate that LAM is required for stamen and runner formation and acts sequentially with GA from bud initiation to runner outgrowth, providing insights into the molecular regulation of these economically important organs in strawberry.

Dynamic simulation of the multilayer crown net photosynthetic rate and determination of the functional crown for larch (Larix olgensis) trees

Pruning can encourage the early formation of knot-free wood with high economic value. However, few studies have assessed the costs and benefits of production in order to determine the optimal pruning design. The concept of a functional crown provides reasonable guidance for pruning, but there is no objective method of determining the functional crown. Semimonthly measurements of leaf traits and photosynthetic characteristics and the corresponding environmental conditions were conducted for young Larix olgensis plantations throughout the entire growing season. The dynamic crown net photosynthetic rate (An) was simulated by comprehensively considering the leaf mass per area, photosynthetically active radiation, air temperature (Tair), vapor pressure deficit and leaf position within the crown (relative depth into the crown, RDINC). The precision (P) was estimated to be 95.5%, indicating that our model performed well in predicting the dynamic crown An for young Larix olgensis plantations. The net primary productivity (NPP) of each whorl of the tree crown was calculated by numerically integrating the instantaneous An. The net carbon contribution from branches to the tree was obtained by subtracting the annual carbon increment from the NPP. The results showed that some live branches in the lower crown contributed negatively to the trunk, indicating that pruning should not focus only on dead branches. Thus, the lower boundary of the functional crown (LBFC) provides a valuable guideline for pruning treatments. Considering that the LBFC will shift upward as the tree grows, we suggest that advanced pruning techniques be applied to reduce costs and minimize labor.

ОСОБЕННОСТИ ВНЕШНЕГО ПРОЯВЛЕНИЯ ПАТОЛОГИЙ НА МЯГКОЛИСТВЕННЫХ ПОРОДАХ

This paper analyzes the patterns of weakening of soft-wooded broadleaved species, provides the frequency of occurrence of the most common external signs of pathologies and their relationship with the general condition of trees. It was found that the most common pathological sign in soft-wooded broadleaved species is drying out of branches (58.2% of the surveyed trees), followed by breakage of skeletal branches (14.9%) and the presence of thick skeletal branches in the crown (14.4% ). Further, as the occurrence of signs decreases, we see trunk inclination of varying degrees (13.9%), where inclination of up to 30° prevails, various pathologies of the trunk shape (12.9%), the most frequent among which was the bifurcation of the trunk, bending of the trunk relative to the normal axis of the tree (7%) and fruiting bodies of wood-destroying fungi (4.1%). Small-leaved linden (Tilia cordata Mill.) was the most stable species in the surveyed plantation, on which the least number of pathological signs was recorded. The revealed features of the external manifestation of pathologies will make it possible to determine the category of the tree state more accurately and increase objectivity and reliability of forest pathological examinations

Effect of Intermittent Long-day Treatment on Flowering of Branch Crown and Yield in Everbearing Strawberry Cultivars

Effect of Intermittent Long-day Treatment on Flowering of Branch Crown and Yield in Everbearing Strawberry Cultivars

Improvement of environmental efficiency of plants of green zones by creation of subordinate crops of Siberian stone pine

It is topical to increase the ecological efficiency of plantings of green zones of settlements by creating Siberian stone pine crops. The subordinate crops of this type, which were created in 1966 by quadrennial seedlings of different geographical origin at thick planting, were observed (9 pieces in a site measuring 0.7 x 0.7 m, the distance between the centers of the sites is 4 m). It was found that the canopy closure of the stand, consisting of birch and pine, has a significant effect on the growth rates of subordinate crops of Siberian stone pine. So at canopy closure 0,1-0,1 52 years old crops, despite the different geographical origin, had the highest rate of height, stem diameter, crown, number and diameter of lateral branches on the lower live node in comparison with the closure of 0.6-1.0 Average increment of branchlets at 32 year period was by 49,8% more in trees, growing at a canopy closure of 0,2 against 0,7-0,8. Trees growing on the open area characterized by early seeding, were selected and propagated by engrafting.

Extreme short-day induction requirements for flowering in the late-flowering strawberry cultivar ‘Malwina’

ABSTRACT We studied short-day induction of the strawberry (Fragaria x ananassa Duch.) cultivar ‘Malwina’ under both phytotron and field conditions. Flowering was assessed by crown dissection of treated plants and subsequent flowering performance. Serial dissections revealed no visible changes in crown apices during the first 4 weeks of short day (SD) at 18°C in the phytotron, while after 6 weeks, all plants had formed rudimentary flower primordia with visible sepals. At 9°C, the same stages were reached after 8 and 10 weeks of SD, respectively. When subsequently forced in long day (LD) at 20°C, no substantial flowering took place after less than 6-week SD treatment at 18°C, while full flowering required 10 weeks of SD induction. At 9°C, full flowering was not obtained even after 10 weeks of SD treatment. Under field conditions, the ‘Malwina’ plants did not reach floral development stage 2 before 22 October, approximately a month after ‘Frida’ and ‘Sonata’ which reached this stage on 21 September, and 3 weeks after ‘Florence’. SD exposure resulted in repeated crown branching in ‘Malwina’ and we suggest that early spontaneous abortion of the emerging floral primordium takes place under unsaturated SD induction conditions, thus causing crown branching and hence, delayed floral initiation and development.

Responses to nitrogen conditioning in ‘Albion’ strawberry (Fragaria X ananassa Duch.) for off-season plasticulture production are primarily qualitative rather than quantitative

The nature (qualitative vs. quantitative) of growth responses to nitrogen during photoperiod conditioning of ‘Albion’ strawberry (Fragaria x ananassa Duch.) plants for late summer / early fall off-season field production was evaluated in New Jersey, USA. For two different planting dates (14 June and 6 July), plants were conditioned in the greenhouse under ND (natural daylength), LD (natural daylength supplemented with 24 h incandescent radiation (Phillips Duramax Soft White A19 60 W) or LD7W (natural daylength supplemented with 24 h incandescent radiation (C9, 7 W bulbs) followed by elevated nitrogen (800 ppm) for 0–4 weeks. Plants were then established in field plasticulture. Flowering in July was enhanced by LD conditioning; however, these effects did not persist and have an impact on plant productivity. Qualitative responses to N included crown branching, runner production, fruiting precocity and early season yield. Results confirm the previous observation that conditioning plants prior to off-season plasticulture production in the Northeast US is not necessary if plants are established in the field by early July. The LD7W light treatment was more effective than the LD light treatment in eliciting photoperiod responses especially when nitrogen levels were low. Thus, the lower wattage bulbs may be an effective tool for managing photoperiod responses for off-season production when needed (later planting dates) with this cultivar.

THE INTENSIVE MANAGEMENT OF NORWAY SPRUCE: A COMPROMISE BETWEEN FINANCIAL GAIN AND GENETIC DIVERSITY?

INTRODUCTION
 Norway spruce (Picea abies (L.) Karst.) is a high-yielding commercial tree species grown in the Baltic sea region. It not only ensures timber production, but also provides a notable amount of crown branch biomass and a substantial amount of technically accessible stump biomass for energy. Thus, it has a high potential as a source of renewable materials and energy in the bioeconomy. Recent studies in Latvia have shown no long-term negative consequences to forest ecosystems from whole-tree harvesting. Hence, this management method can be considered sustainable for Norway spruce stands in fertile mineral soils. Not only yield, but also risks need to be considered to ensure financial sustainability, mainly the impact of wind-storms, drought, and pests. A combination of silviculture and genetics (tree breeding) can be used to reduce the probability of damage to Norway spruce stands. The aim of our study was to assess the potential of simultaneously ensuring both genetic gain and diversity in Norway spruce plantations.
 MATERIALS AND METHODS
 Data characterizing/showing tree growth – current height, diameter at breast height, survival, as well as radial increment (increment cores) – were obtained from a 50-year-old Norway spruce plantation. Data characterizing genetic diversity were collected from a gene reserve stand (48 trees), Norway spruce seed orchard progenies consisting of 20 clones, as well as 12 pure Norway spruce stands. DNA was extracted and analysed with 6 to 14 nuclear SSR markers.
 RESULTS
 No significant differences were observed between the seed orchard progenies, the trees from the gene reserve stand and other Norway spruce stands using the assessed parameters – allelic richness, observed heterozygosity, genetic diversity and relatedness. This indicates that the use of a seed orchard containing a relatively low number of clones as a seed source for plant production and forest regeneration would not have a negative impact on genetic diversity. However, notable gains in productivity can be achieved using selected plant material. At the age of 50 years, phenotypically selected clones in the low-density (5×5m) plantation had a mean yield of 327±42 m3ha-1, significantly exceeding the mean yield (277±56 m3ha-1) observed in Norway spruce stands of the same age and the same site conditions (forest type), while no significant differences were observed compared to the average stand yield at the age of 80 years (347±47 m3ha-1). The target diameter of 31 cm was reached at the age of 42±0.9 years on average, but this varied significantly among clones.
 CONCLUSION
 The results demonstrate a notable potential to reduce the rotation period, thereby: a) increasing the availability of raw material for further processing and energy production, and b) reducing financial risks due to lowering the probability that the stand will sustain substantial damage (i.e. wind storm). This gain can be achieved without significantly compromising genetic diversity. Further studies shall address potential changes in genetic diversity at the landscape level over a longer period when using a very limited set of clones. Stands in nature reserves could serve as a basis for comparison in such studies.