Picea Abies Seedlings Research Articles

Light quality and intensity of light-emitting diodes during pre-cultivation of Picea abies (L.) Karst. and Pinus sylvestris L. seedlings – impact on growth performance, seedling quality and energy consumption

ABSTRACTThree different LED lamps with continuous spectra were compared against commonly used fluorescent lights. The lamps were characterized by light output, energy consumption and spectral quality for plant growth. The biological effects of light quality were compared by pre-cultivating seedlings of Picea abies (L.) Karst. and Pinus sylvestris L. under each spectrum for 35 days in a growth chamber with controlled temperature, humidity and photoperiod. The seedlings were then transplanted and cultivated for one vegetation period at the nursery, then planted outdoors on a forest field trial and followed for three years. The seedlings showed similar growth performance for all spectra tested. LED lamps have several advantages to fluorescent light such as energy consumption, longer life span and adjustable light intensity. Regarding light intensity the effects on growth performance were studied for both species using the most promising LED spectra. The photosynthetically active radiation (PAR) was maintained at 50, 100, 200 and 400 μmol m−2 s−1. Unlike energy consumption, seedling development did not display a linear relationship to light intensity. Instead, the results show an optimum light level between 100 and 200 μmol m−2 s−1 for the shade tolerant Picea abies seedlings and a level of around 200 μmol m−2 s−1 for the more shade intolerant Pinus sylvestris seedlings.

Survival, Growth and Mycorrhization of Containerised Pinus sylvestris and Picea abies Seedlings of Different Provenances Outplanted in a Forest Clear-Cut

Abstract We studied field performance of containerised Pinus sylvestris and Picea abies seedlings of different provenances. Shoot height, needle chemical composition, root collar diameter, root mycorrhization and mycorrhizal species composition were evaluated after four growing seasons following outplanting. The results showed that in general spruce had better survival than pine. Ectomycorrhizas on spruce were dominated by Wilcoxina, Amphinema and Tylospora, while on pine — by Suillus and Thelephora species. Spruce and pine showing best growth rates were colonised by ectomycorrhizal fungus Amphinema sp. In conclusion, the results demonstrated that forest nursery practices as well as provenance can significantly impact survival, growth and mycorrhization of the containerised pine and spruce seedlings.

Effect of photoperiod and fertilization on shoot and fine root growth in Picea abies seedlings

Effect of photoperiod and fertilization on shoot and fine root growth in Picea abies seedlings

Seedling responses to changes in canopy and soil properties during stand development following clear-cutting

The role of natural regeneration in silvicultural systems is attracting increasing interest, but much is unknown about how stand development after clear-cutting affects seedling regeneration. We looked at the impact of tree canopy and ground layer vegetation (i.e., ‘stand type’) as well as soil properties (i.e., ‘soil origin’ or stand from which soil originated) on survival and growth of Pinus sylvestris and Picea abies seedlings at three forest developmental stages, i.e., 4, 16 and 34years after clear-cutting. To do this we transplanted soil cores between stands of different stages to separate the effects of soil properties versus canopy closure on seedling performance. We found that seedling survival of both species was highest when planted in the oldest stands independent of soil origin. P. sylvestris seedling growth responded to stand type but not soil origin, and biomass was highest at the youngest stand likely because of greater light availability. Meanwhile, although P. abies seedling root biomass responded to stand type, this species was mostly responsive to soil origin, with shoot and total biomass being greatest when seedlings were grown in soil originating from the oldest stands. These findings have implications for our understanding of tree regeneration of species that differ in their responsiveness to light and soil characteristics. The results can further inform forest managers about how to optimize survival and growth of seedlings by means of canopy regulation as well as provide information to assist the regeneration and development of multi-storied forest stands.

The Formation of Steppe and Protective Afforestation Basement: Theoretical and Applied Aspects

Introduction. Fusarim are widely spread in forest nurseries. It is difficult to identify Fusarium species using microbiological methods. The goal of this study was to identify the micromycetes of Fusarium genus isolated from Pinus sylvestris and Picea abies seedlings and to develop a method of species identification for F. oxysporum, F. verticilliodes, and F. graminearum based on the restriction analysis of amplified ribosomal DNA. Objects and research methodology. The universal primers ITS1 and ITS4 were used in the study. A PCR-product of about 550 base pairs for each Fusarium species was generated. Three Fusarium species (F. oxysporum, F. verticilliodes, and F. graminearum) were identified by the molecular genetic analysis based on the sequence of ITS rDNA region. Since these fungi are difficult to distinguish by morphological markers, a simple method based on the digestion by restriction endonucleases of ITS1-5,8S-ITS2-28S region was developed. Five restriction endonucleases (AluI, BstMBI, BstHHI, BsuRI, and HpaII) were used for digestion of the studied DNA. Research results. Only HpaII and BstHHI allowed to get the unique RFLP banding patterns for each Fusarium species. When using the restrictase HpaII, a unique fragment over 440 bp for F. oxysporum and two fragments over 300 bp and 160 bp for F. verticilloides were identificated. The digestion of PCR fragments by using BstHHI enzyme revealed two specific fragments (300 bp and 280 bp) for F. oxysporum and two fragments (300 bp and 190 bp) for F. verticilloides. Conclusion. The PCR-RFLP analysis of the amplified ITS region was proved to be a useful molecular tool for identification of F. oxysporum, F. verticilliodes, and F. graminearum.

ОЦЕНКА ВОЗДЕЙСТВИЯ МОДИФИЦИРОВАННЫХ ЛИГНОСУЛЬФОНАТОВ НА ВЕГЕТАЦИЮ СОРНЯКОВ И СЕЯНЦЕВ ЕЛИ В ЛЕСНЫХ ПИТОМНИКАХ

ОЦЕНКА ВОЗДЕЙСТВИЯ МОДИФИЦИРОВАННЫХ ЛИГНОСУЛЬФОНАТОВ НА ВЕГЕТАЦИЮ СОРНЯКОВ И СЕЯНЦЕВ ЕЛИ В ЛЕСНЫХ ПИТОМНИКАХ

Herbivory on young tree seedlings in old‐growth and managed mountain forests

AbstractHerbivory of invertebrates and rodents on tree seedlings in Northern temperate forests has been largely underestimated in the past and rarely addressed in studies. There is evidence that masting‐cycles of forest trees and subsequent rodents outbreaks become more frequent, leading to enhanced browsing pressure on forest regeneration. Consequently, studies exploring tree seedling mortality caused by different herbivores are required. We conducted a study on tree seedling losses in the Wilderness Area Dürrenstein, Austria on two old‐growth and one managed forest site. We conducted an exclosure experiment in two subsequent study years, using transplanted two‐month‐old tree seedlings of Picea abies, Abies alba, and Fagus sylvatica. Exclosures allowed access for invertebrates, invertebrates/rodents, and all potential herbivores. We also installed total exclosures, recording seedling losses due to climatic factors or pathogens. We calculated ZINB regressions assuming that seedling losses and seedling survival are distinct processes. Our results did not reveal fully consistent trends for both study years. The factor “treatment”, however, was significant in the ZINBs in both study years. Herbivory was a driving factor for tree regeneration in the studied forests depending on specific conditions in different years or tree species. In 2005, losses in the total exclosures and herbivory of rodents and invertebrates in the other treatments reached comparable extent. Loss rates differed not only in terms of forest management, but also between the two old‐growth forests. This, in connection with different herbivory of different tree species (higher losses of A. alba), strongly suggests the necessity of considering different herbivore guilds as drivers of tree species composition in late successional mountain forests.

Root-associated fungi of healthy-looking Pinus sylvestris and Picea abies seedlings in Swedish forest nurseries

The aim of this study was to assess fungal communities in roots of healthy-looking Pinus sylvestris L. and Picea abies (L.) Karst. seedlings in nine forest nurseries in Sweden using a combination of traditional culturing and direct sequencing of internal transcribed spacer of fungal ribosomal RNA (ITS rRNA) from the roots. Culturing from 1800 surface-sterilised root segments resulted in 2387 fungal cultures representing 42 different taxa. Direct sequencing from 180 root segments resulted in 119 ITS rRNA sequences representing 25 different taxa. In total, 55 different fungal taxa were detected using both methods. Although direct sequencing was more efficient than culturing in detecting different fungal taxa, both methods provided complementary information about fungal communities in roots since each detected rather different groups of fungi. The most dominant taxa detected by culturing were Trichoderma viride Pers. (19.5%), Phoma mucivora Davey & Currah (19.1%), Phialocephala fortinii Wang & Wilcox (17.4%) and Meliniomyces variabilis Hambl. & Sigler (10.2%), while Thelephora terrestris Ehrh. (26.1%), Unidentified sp. NS126 (25.2%) and Heliotales sp. C20 (10.1%) were most commonly detected by direct sequencing. In conclusion, results showed that forest nurseries in Sweden harbour diverse communities of fungi associated with the roots of healthy-looking P. sylvestris and P. abies seedlings. Although fungal communities were often dominated by saprotrophs and endophytes, several facultative pathogens were also detected indicating that under suitable conditions they may be a potential threat to the plants.

UV -B Exposure of Indoor-Grown Picea abies Seedlings Causes an Epigenetic Effect and Selective Emission of Terpenes

Terpenoids are involved in various defensive functions in plants, especially conifers. Epigenetic mechanisms, for example DNA methylation, can influence plant defence systems. The purpose of the present study was to investigate the influence of UV-B exposure on the release of terpenoids from spruce seedlings and on needle DNA methylation. Ten-week-old seedlings grown indoors were exposed to UV-B radiation during 4 h, and the volatile compounds emitted from the seedlings were analysed. Analysis of the volatiles 1, 3, and 22 d after this UV-B exposure showed that bornyl acetate, borneol, myrcene, and limonene contents increased during the first 3 days, while at day 22 the level of emission had returned to the control level. UV-B exposure decreased the level of DNA methylation in needles of young seedlings, reflected in methylation changes in CCGG sequences. Exposure of young seedlings to UV-B radiation might be a way to potentiate the general defensive capacity, improving their ability to survive in outdoor conditions. UV-B-induced defence is discussed in the light of epigenetic mechanisms.

Timing and duration of short-day treatment influence morphology and second bud flush in Picea abies seedlings

A slower reaction of diameter growth cessation compared to that of height growth in response to short day (SD) treatment is well documented in Picea abies (L.) Karst. seedlings, suggesting that the height/diameter ratio of seedlings could be controlled through appropriate timing and/ or duration of SD treatment is forest nurseries. Here, we applied specific combinations of timing (starting date 20 and 27 June, 4 or 11 July) and duration (7, 10, 14 or 17 days) of SD treatment to assess the possibility of obtaining more sturdy seedlings. We observed a rapid and uniform height growth cessation following SD treatment compared with the delayed cessation of diameter growth. Height growth responded significantly only to starting date of SD treatment, resulting in taller seedlings for later starting dates. Diameter growth responded to the duration of SD treatment, with significantly less diameter growth in seedlings exposed to 14 or 17 days of SD treatment than in seedlings exposed to 7 or 10 days of SD treatment. Also starting date influenced diameter growth, resulting in significantly more diameter growth with the earliest starting date compared with the two latest starting dates of the SD treatment. A second bud flush occurred only in seedlings exposed to SD treatment starting on 20 or 27 of June and only following 7–14 days of duration. This implies a need of longer duration if the SD treatment starts early. This will be at the expense of sustained diameter growth, thus compromising the objective of obtaining more sturdy seedlings.

Effects of Hydrogels on Tree Seedling Performance in Temperate Soils before and after Water Stress

Super Absorbent Polyacrylate (SAP) hydrogels absorb and store water thereby aiding plant establishment when incurporated in the soil. The effect of cross-linked SAP hydrogel amendment on the performance of tree seedlings of Picea abies, Pinus sylivestris and Fagus sylvatica grown in temperate soils under water stress and non-water stress periods was investigated in a green house. The objective was to compare the root and shoot biomass of seedlings of the three species grown in sand, loam and clay soils amended with 0.4% w/w hydrogel in non water stress conditions as well as survival, root and shoot biomass after subjection to water stress. The seedlings were grown for 16 weeks, harvested and shoot as well as root biomass determined before water stress. The seedlings were also subjected to water stress and their biomass assessed at death following the water stress. The results showed that root and shoot biomass were generally higher in hydrogel amended soils compared to the controls. Root and shoot biomass of Fagus sylvatica was lower compared to Picea abies and Pinus sylivestris before water stress. The 0.4% hydrogel amendment significantly increased species’ survival in the different soils studied. Although root biomass was higher in hydrogel amended sandy soil compared to other soils, P. sylivestris and F. sylvatica shoot biomass were higher in hydrogel amended clay and loam soils compared to the sandy soil after water stress. Biomass was higher in sand compared to loam and clay soils under non-water and water stressed conditions. Since SAP hydrogel amendment improved the survival and biomass production of tree seedlings before and after water stress, use of SAPs could be promoted to enhance seedling production in water stress and non-water stress environments.

UV-B Exposure of Indoor-Grown Picea abies Seedlings Causes an Epigenetic Effect and Selective Emission of Terpenes

Terpenoids are involved in various defensive functions in plants, especially conifers. Epigenetic mechanisms, for example DNA methylation, can influence plant defence systems. The purpose of the present study was to investigate the influence of UV-B exposure on the release of terpenoids from spruce seedlings and on needle DNA methylation. Ten-week-old seedlings grown indoors were exposed to UV-B radiation during 4 h, and the volatile compounds emitted from the seedlings were analysed. Analysis of the volatiles 1, 3, and 22 d after this UV-B exposure showed that bornyl acetate, borneol, myrcene, and limonene contents increased during the first 3 days, while at day 22 the level of emission had returned to the control level. UV-B exposure decreased the level of DNA methylation in needles of young seedlings, reflected in methylation changes in CCGG sequences. Exposure of young seedlings to UV-B radiation might be a way to potentiate the general defensive capacity, improving their ability to survive in outdoor conditions. UV-B-induced defence is discussed in the light of epigenetic mechanisms.

Frost hardiness, carbohydrates and bud morphology of Picea abies seedlings after different lengths of freezer storage

In Nordic conditions, conifer seedlings are frozen stored up to eight months. However, there is only little information on the extended freezer storage (more than six months) on frost hardiness (FH) and carbohydrate concentrations in the shoots of Norway spruce seedlings. FH of two-year-old Norway spruce [Picea abies (L.) Karst.] container seedlings were placed in storage on 23 October and kept in storage for 172, 193, 228 or 256 days. Bud structure and carbohydrate concentrations of the needles were analysed. DT50 (temperature causing 50% increase in proportion of needles, stem and buds after freezing exposure) of the measured parts of the seedlings decreased, and changes in DT50 of buds and stems were small between the 172nd and the 193rd day of freezer storage. The concentration of starch increased and the concentration of soluble sugars decreased during the first 172 days of freezer storage. Longer duration of freezer storage, however, did not cause any further changes. The first phase of bud development (pointed lower needle primordial) was already seen in the autumn. The bud development did not change during freezer storage but both the length of the primordial shoot and that of the whole bud increased from October through mid-July. This study suggests that Norway spruce seedlings can be frozen-stored safely for longer periods (eight to nine months) than they are generally stored for currently (six to seven months).

Development of a molecular test to determine the vitality status of Norway spruce (Picea abies) seedlings during frozen storage

In boreal forest regions, a great portion of forest tree seedlings are stored indoors in late autumn to prevent seedlings from outdoor winter damage. For seedlings to be able to survive in storage it is crucial that they store well and can cope with the dark and cold storage environment. The aim of this study was to search for genes that can determine the vitality status of Norway spruce (Picea abies (L.) Karst.) seedlings during frozen storage. Furthermore, the sensitivity of the ColdNSure™ test, a gene activity test that predicts storability was assessed. The storability of seedlings was tested biweekly by evaluating damage with the gene activity test and the electrolyte leakage test after freezing seedlings to −25 °C (the SELdiff-25 method). In parallel, seedlings were frozen stored at −3 °C. According to both methods, seedlings were considered storable from week 41. This also corresponded to the post storage results determined at the end of the storage period. In order to identify vitality indicators, Next Generation Sequencing (NGS) was performed on bud samples collected during storage. Comparing physiological post storage data to gene analysis data revealed numerous vitality related genes. To validate the results, a second trial was performed. In this trial, gene activity was better in predicting seedling storability than the conventional freezing test; this indicates a high sensitivity level of this molecular assay. For multiple indicators a clear switch between damaged and vital seedlings was observed. A collection of indicators will be used in the future development of a commercial vitality test.

Influence of irradiance on chlorophyll synthesis in Picea abies calli cultures

Dark-grown seedlings of Picea abies (L) Karst. are able to accumulate the highest amounts of chlorophyll (Chl) and its precursor protochlorophyllide (Pchlide) in all Pinaceae, but calli derived from 14-d-old green cotyledons of P. abies are completely white during the cultivation in the dark. Pchlide reduction is catalysed in the dark by light-independent protochlorophyllide oxidoreductase (DPOR). This enzyme complex consists of three protein subunits ChlL, ChlN and ChlB, encoded by three plastid genes chlL, chlN and chlB. Using semiquantitative RT-PCR, we observed very low expression of chlLNB genes in dark-grown calli. It seems, that chlLNB expression and thus Chl accumulation could be modulated by light in P. abies calli cultures. This hypothesis is supported by the fact, that we observed low contents of glutamyl-tRNA reductase and Flu-like protein, which probably affected Chl biosynthetic pathway at the step of 5-aminolevulinic acid formation. ChlB subunit was not detected in dark-grown P. abies calli cultures. Our results indicated limited ability to synthesize Chl in callus during cultivation in the dark.

Effect of mini-plug container depth on root and shoot growth of four forest tree species during early developmental stages

The container type used in nursery culture is among the most important determinants of containerised seedling quality. The objective of the present study was to analyse root and shoot growth, root growth potential, and photochemical efficiency of seedlings of Picea abies, Robinia pseudoacacia, Pinus brutia, and Pinus nigra cultivated for 5 weeks in mini-plugs of 2 different cavity depths (37 and 60 mm). The results showed that precultivation of P. nigra and, to a lesser extent, of R. pseudoacacia in deeper mini-plug containers improved seedling morphological attributes and quality, but shallow containers produced better quality seedlings of P. abies. In P. brutia, the use of shallow containers led to the development of a superior root system, while the use of deeper containers produced seedlings with better above-ground characteristics.

Mycorrhization, establishment and growth of outplanted Picea abies seedlings produced under different cultivation systems

In forest nurseries seedlings are commonly produced using different cultivation systems which may have a profound effect on the extent of root colonisation by ectomycorrhizal (ECM) fungi and, consequently, on subsequent performance of the outplanted seedlings under field conditions. In this study, we compare effects of bare-root and containerised cultivation systems on mycorrhization, establishment and growth of nursery-produced Picea abies. One hectare experimental plantation was established on poor fertility sandy site. In total, 1250 seedlings of each treatment were planted in rows as ten individual replicates. The results of this study showed that production of P. abies seedlings using containerised system can yield abundant ECM colonisation of seedling roots and significantly improve seedling survival in the field. Some reduction in height increment may occur during the first years as a possible cost for support of ECMs. Study demonstrated that selection of proper cultivation system might result in similar or higher mycorrhization and survival rates of outplanted seedlings than achieved by expensive and laborious artificial mycorrhization.

Differential photosynthetic adaptation between size-classes of Spruce and Fir juveniles help to explain the co-existence of the two species.

Abstract Background/Question/Methods _Abies sachalinensis_ (Sakhalin Fir) and Picea glehnii (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change.Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of these species, on different developmental stages.The study is taking place on a sub-boreal forest plot in north Japan (N 44º 19’, E 142º 15’). Twenty shade-growing individuals of both species were divided into two height classes: seedlings, if height < 50cm; and saplings, if height > 100cm. The canopy coverage over each individual was assessed by analyzing hemispherical photography and average light incidence. Leaf pigments are being analyzed by chromatography. Light response curves and chlorophyll fluorescence are being measured seasonally, except in winter. Results are analyzed through General Linear Models. The study period was from spring 2009 to summer 2010. Results/Conclusions Results show an inversion of the photosynthetic adaptation between seedlings and saplings, and also between species. Picea seedlings and Abies saplings have greater total chlorophyll content and higher photosynthetic rates than Picea saplings and Abies seedlings. As a consequence, the superior competitor between similar sized individuals of both species appears to change between size-classes, with Abies presenting higher photosynthetic rates at the sapling class and Picea at the seedling class. Nevertheless, no significant growth has been observed in any of the groups until now. Results also disagree with some of the previously reported photosynthetic characteristics of these species, with Picea seedlings displaying more traits usually associated with shade adaptation than Abies seedlings.

Differences in growth and nutrient uptake from a coarse-soil substrate by ectomycorrhizal- and fungicide-treated Picea abies seedlings

In order to quantify the importance of ectomycorrhizal fungi on nutrient uptake from the coarse-soil fraction of a haplic Cambisol (alumic), a microcosm study that allowed for nutrient budgets was designed. Ectomycorrhizal- and fungicide-treated spruce seedlings were grown on isolated and cleaned gneiss fragments (6.3 mm > O > 2 mm) from 90 cm soil depth. The substrate was the only source of Ca, K and Mg. Ectomycorrhizal seedlings showed no signs of nutrient deficiencies and biomass increased significantly compared to initial seedling biomass. Ectomycorrhizal seedlings seemed well adapted to survive on the coarse-soil substrate and acquired Ca, K and Mg from the coarse-soil substrate. Gneiss fragments of the ectomycorrhizal treatment were covered by fine roots and ectomycorrhizal hyphae, as observed microscopically. Fungicide-treated seedlings’ root development was retarded, and shoot biomass only increased from stored nutrient reserves of the seedlings. The suppression of EcM colonization by the fungicide Topas® apparently caused a root growth inhibiting effect. Furthermore, the extinction of mycorrhiza initiated an increased nitrification and acidification and a consequent nutrient cation release triggered by nitrate in the drainage.

Establishment of planted Norway spruce and Scots pine seedlings: effects of light environment, fertilisation, and orientation and distance with respect to shelter trees

The effects of stand stem density (SSD), orientation and distance with respect to shelter trees, and fertilisation on planted Pinus sylvestris and Picea abies seedlings were examined at two sites, one with a southerly aspect (64°14′N, 19°46′E, 225 m a.s.l.) and one with a northerly aspect (64°09′N, 19°36′E, 274 m a.s.l.) in boreal forests in Sweden. The damage and growth were compared at these sites in stands with three SSD’s and different light regimes: uncut forest (SSD 500, ~500 stems/ha), shelterwood (SSD 150,~150 stems/ha), and clear-cut (SSD, 0 stems). Half of the seedlings were irrigated with fertiliser (10 mM N). Fertilisation and SSD affected the height growth of P. abies, since fertilised seedlings in SSD 0 grew the most (22.2 cm). Fertilised seedlings in SSD 0 also generally had the greatest biomass (twigs, leading shoot and needles), even P. sylvestris seedlings on the North slope, where fertilised and unfertilised pine seedlings in SSD 0 had 62.6 and 39.7 g biomass, respectively. P. sylvestris increased about 150% in dry mass of leading shoot of the increase of P. abies with equal height growth, when comparing SSD 150 and SSD 0. The results indicate that the general conditions of the stand have stronger effects on the growth of planted seedlings than their orientation and distance with respect to the nearest tree and that light requirements cannot be moderated by fertilisation. We postulate that a system in which forest gaps are formed under a shelterwood could provide a way to regenerate forests that exploits the beneficial features of both shelter trees and clear-cuts.