Pathogenicity of Thekopsora areolata from seed orchards in Finland on Prunus spp. and Picea abies

Pathogenicity of cherry‐spruce rust, Thekopsora areolata, was investigated by inoculations with aeciospores from seven Norway spruce, Picea abies, seed orchards that had suffered from successive severe rust epidemics in the 2000s in Finland. Detached leaves of Prunus spp. were inoculated in the laboratory using aeciospores from cones of various ages. In the greenhouse, live Prunus padus plants were inoculated, and possible autoecism of the rust was tested by inoculations of Picea abies seedlings. Thirty‐five spore sources from the seed orchards formed uredinia on Prunus spp. in the laboratory 2 weeks after incubation, but no telia developed. In the greenhouse, uredinia developed on live P. padus, but no rust symptoms, cankers or sporulation were detected on Picea abies. Thus, no evidence of autoecism was observed among the T. areolata populations and therefore all populations, suggesting all those tested from the Finnish seed orchards were heteroecious.     

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.     

Rhizina undulata on Picea abies transplants

At least three quarters of the sites of brash fires in a mainly coniferous area on peat in Co Tyrone, Northern Ireland were clonised by Rhizina undulata. On each of these sites an average of eight newly planted Picea abies died within five years. No more deaths were recorded during a further three years. Deaths of Picea abies seldom occurred where there had been no fire or on fire sites on hardwood stumps in the same area.     

挪威云杉扦插繁殖技术研究

利用3~5年生挪威云杉半木质化枝条开展了挪威云杉扦插激素种类、激素浓度、浸泡时间、插穗长度、扦插深度、插穗预处理和挪威云杉各家系扦插繁殖对比等方面的研究,结果表明:激素种类、激素浓度、浸泡时间不同水平之间具有显著差异,选用ABT1、50×10-6、浸泡50min试验效果最好;不同扦插深度试验中各扦插深度水平之间差异不显著,但以扦插深度5cm生根率最高,平均达68.89%,最高可达96.67%;各插穗长度水平之间差异不显著,但以插穗长度10cm生根率最高,平均达88.33%,最高可达90%;挪威云杉不同家系扦插的生根率存在显著差异。     

欧洲云杉引种试验研究

为确定鄂西地区欧洲云杉的适生区域,进行欧洲云杉德国种源引种栽培试验,试验结果表现良好,25 a生林分树高13.2 m,平均胸径19.8 cm,材积0.206 2 m3,材积比人工林杉木、巴山松、油松提高38.7%~46.9%。海拔区域试验表明6 a生欧洲云杉林分树高生长量在海拔1 060~1 916 m差异不显著,适宜鄂西山区海拔1 500~1 900 m,年降水量1 000mm以上的区域营造工业原料林或种子园。     

欧洲云杉、黑云杉、白云杉苗期对比试验

选择欧洲云杉3个种源、黑云杉3个种源、白云杉3个种源、青海云杉1个种源进行了不同种、种源的苗期生长性状变异试验。结果表明：云杉不同种、种源间苗期性状差异显著。4个种的1年生苗以苗高进行排序：欧洲云杉〉黑云杉〉白云杉〉青海云杉。欧洲云杉、黑云杉、白云杉各个种的不同种源间有很大的变异及选择潜力。因此在进行云杉引种时,应选择不同的种、种源,才能取得更好的效果。     

Allozyme Variation of Picea abies in Poland

The aim of this study was to determine the levels and patterns of allozyme variation among 29 populations of Norway spruce [ Picea abies (L.) Karst.] from Poland. Thirteen investigated isoenzyme systems were encoded by 27 gene loci and, on average, 71% of the loci per population were polymorphic. The average and effective numbers of alleles per locus were 2.17 and 1.26, respectively, while the expected heterozygosity was 0.156. A relatively low allozyme differentiation among populations from north-eastern and southern Poland was observed ( F ST = 0.028, mean genetic distance D = 0.005). The results suggest that historical events and extensive gene flow played an important role in the distribution of the observed allozyme differentiation of Norway spruce in Poland.     

Environmental influences on juvenile shoot growth in Picea abies

Under certain environmental conditions, juvenile shoot growth characters might give early indications of adaptability and growth potential. Therefore, the reaction patterns of predetermined and free shoot growth were studied on Picea abies (L.) Karst, plants, which at different times during the growth period were treated by (1) application of nutrients, (2) defoliation, and (3) short days. Fertilization caused an increase in both predetermined and free growth, while defoliation and short day treatment caused a decrease in both forms of shoot growth and short days did not allow any free growth to occur. In the growth period following the treatments, fertilization caused more predetermined and less free growth to occur, while defoliation caused less predetermined and more free growth. Predetermined growth is explainable by the finite number of predetermined needle primordia. Free growth is initiated thereafter. It is influenced strongly by the environmental conditions and seems not to be influenced by the amount of preceding predetermined growth. Free growth enables young plants to utilize favourable growth conditions in summer for height growth precociously, which might increase their adaptability and competitive value. However, predetermined growth is the preferable mode of shoot growth because favourable conditions in successive growth periods induce more predetermined than free growth. Predetermined and free growth are well integrated forms of shoot growth giving no supporting evidence to the hypothesis that free and predetermined growth are inherited independently of each other. Rank changes in provenance development are probably not explainable by a loss in height growth when free growth occurs no more due to age, but by other causes.     

Estimated bud development period in Picea abies

The bud development period was estimated using shoot growth data from a Phytotron study in which six full‐sib families of Picea abies L. (Karst.) (Norway spruce) were grown for six growth periods. Simple algebraic relationships based on assumptions of the relationship between shoot growth and bud development were used. The estimated bud development period, defined as the period when the budscale and needle primordia were initiated, decreased as growth periods advanced. Furthermore, the relationship between the period of production of free growth needles and bud scales to that of predetermined needle primordia was surprisingly constant irrespective of the change in free growth. These results indicate that free growth during one year did not encroach on the period of predetermined growth, but instead increased the amount of predetermined growth.     

Growth in supplementarily planted Picea abies regenerations

Abstract

An experiment was established in 1978 in two Norway spruce [Picea abies (L.) Karst.] plantations in southern Sweden to study yield after mortality in patches with and without supplementarily planted (SP) seedlings. Gaps of different sizes were created by removing the originally planted seedlings. The gaps were either left unplanted or a supplementary planting was performed with one of four species [Norway spruce, Scots pine (Pinus sylvestris L.), lodgepole pine (Pinus contorta Dougl.) or hybrid larch (Larix deciduas Mill×L. Leptolepis Gord.)] 2 (at Knäred) or 6 years (at Ullasjö) after the original plantation. In 2002, most of the SP Scots pine, lodgepole pine and hybrid larch seedlings were dead or severely damaged by roe deer and moose. Survival was high among SP Norway spruces, but they had slower growth than the originally planted spruces. Growth was lower at Ullasjö than at Knäred. In Ullasjö, growth was lower in small gaps than in large gaps. Trees in original regeneration in areas surrounding unplanted gaps were larger than trees surrounding gaps with SP seedlings, which in turn were larger than originally planted trees in plots without gaps. In conclusion, because the original plantation surrounding unplanted gaps used a large part of the open space and growth of SP seedlings was slow, supplementary planting resulted in an insignificant growth increase. However, supplementary planting may increase the timber quality of trees surrounding the gaps, although this effect remains to be quantified.     

Microflora of sound-looking wood in Picea abies stems

Ascocoryne spp. (A. cylichnium and A. cf. sarcoides) were found in 48 % of 262 60-year-old Picea abies stems. They were isolated with increasing frequency towards the pith from the lower 2-3 m, more often from thicker than from thinner stems. Neobulgaria premnophila was present in 10 % of the stems, more evenly distributed, and with no difference in occurrence between thicker and thinner stems. Nectria fuckeliana was situated at random in 8 % of the trees.     

Crown development in young Picea abies stands

A dynamic model of branch length and weight growth was developed for two contrasting sites, both with young stands of spruce. At one site sample trees were obtained from both unfertilised plots and from plots with increased growth rate maintained by annual fertilisation. At the second site unfertilised trees and trees subject to single applications of fertiliser were modelled. A model of the same structure was developed for each site and tested by application at the alternate site. In view of the close agreement between sites, model parameters were calculated based on all data combined. The model is driven by height increment and branch age. The sample trees were mostly open grown so that only a tentative estimate of the effects of between tree competition is given. The limitations of the model are stressed.     

Association of the pine-infesting Pissodes species with ophiostomatoid fungi in Poland

Bark weevils are consistently associated with various fungi. They act as effective vectors for root-rot fungi, the rust pathogen and the ophiostomatoid fungi. In comparison with bark beetles, the interaction between ophiostomatoid fungi and bark weevils has been poorly studied in Europe. This study aims to clarify the ties among ophiostomatoid fungi and their weevil vectors in Pinus sylvestris. Samples associated with three bark weevils, including Pissodes castaneus, P. piniphilus and P. pini were collected from seven pine stands in Poland. Fungi were isolated from laboratory-reared and field-collected beetles, larvae and galleries of weevils. Isolates were identified based on morphology, DNA sequence comparison for two gene regions (ITS, ß-tubulin) and phylogenetic analyses. Fourteen morphological and phylogenetic ophiostomatoid species were identified among the 1,219 isolates. These 14 species included 11 novel associations between fungi and bark weevils. The most commonly encountered fungal associates of bark Pissodes species were Leptographium procerum, Ophiostoma quercus and O. minus. The spectrum of fungal associates was similar in three bark weevil species, despite some differences between species. Except for P. castaneus, all species of bark weevil were frequently associated with ophiostomatoid fungi. Pissodes castaneus does appear to be a consistent vector of L. procerum and Sporothrix inflata while O. minus, O. quercus and O. cf. rectangulosporium were often found in association with P. piniphilus and P. pini.     

Rapid yellowing of needles of Picea abies

Severe chlorosis developed in a 45 year old stand of Norway spruce over a period of three weeks in July and August 1986. The chlorosis was followed by needle necrosis and, eventually, shedding. The trees showing the most severe effects had all been damaged during timber extraction operations in 1985. The symptoms superficially resembled those on many trees in central Europe, Where air pollution is generally considered to be involved in chlorosis and defoliation. Air pollution is unlikely to be a primary factor in the chlorosis and defoliation observed in this stand.     

Effects of aluminium and calcium on Picea abies seedlings

Newly‐germinated Norway spruce seedlings were grown for 15 weeks in pots of iron podzol soil that received additions three times a week of nutrient solution containing six levels of Al (0, 0.37, 0.74, 1.5, 3.0 or 6.0 mM) and two levels of Ca (0.09 or 0.46 mM). The Ca concentrations in shoots and roots decreased with increasing Al levels. Growth was suppressed at 0.74 mM Al in the nutrient solution, which gave 0.5 mM Al in saturated soil extracts at the end of the experiment.     

补充光照对欧洲云杉苗木生长的影响

光周期具有抑制苗木早期休眠,延长其生长期的作用,具有促进欧洲云杉苗木生长的作用,其在形态指标和生物量上表现得极显著.欧洲云杉大棚育苗补充光照的完整技术可采用整夜补光,随着光强度的增加,苗木生长形状各指标呈渐增的趋势.光质以白光较好.     

Effects of early cleaning on young Picea abies stands

Young Norway spruce stands (Picea abies [L.] Karst) are typically cleaned of non-crop species on one or several occasions during young stand stage. In order to objectively evaluate the perceived benefits of early cleaning (EC), we studied the effects of EC on three study sites 2–2.5 years after receiving the treatment. Experiments were established as a randomised complete block design with a total of 40 blocks. Although height growth and mortality were not significantly affected, we found that EC substantially reduced canopy competition and, consequently, the mean diameter of released spruce grew 21–32% faster depending on the site. Furthermore, non-crop trees that were cleared during EC had fewer sprouts in two of the three sites and the sprouts were substantially smaller than the corresponding non-crop trees on control in all sites. EC can reduce the cost of pre-commercial thinning because EC reduced the estimated time needed for subsequent management by 18–49%. Thus, EC offers forest owners and managers an economically viable young stand management option.     

Wound occlusion and decay in Picea abies stems

In forest stands, Picea abies is commonly subjected to logging and bark stripping injuries. Most mechanical wounds do not exceed 300 cm², but their pathological consequences are unclear. The aim of the study was to estimate the rate of wound occlusion and the probability of decay in P. abies stems in relation to initial wound size and wounding season. The study included forty-five stems with 1-, 2-, 3-, 4- and 5-cm-wide by 15-cm-long wounds (15–75 cm²), and eighty-three stems with 15-cm-wide by 20-cm-long wounds (300 cm²), made either in January or in August. After 19–21 years, each wound was assessed for occlusion rate and the presence of decay. All 1- to 2-cm-wide wounds were occluded, compared to 58–70% of the 3- to 4-cm-wide wounds, 25% of the 5-cm-wide wounds, and 0% of the 15-cm-wide wounds. On average, it took 3.6, 5.5, 10.4, 12.7 and 14.7 years to occlude wounds ranging in size from 1- to 5-cm-wide, respectively. After 21 years, the observed size of wounds comprising an initial area of 300 cm² ranged between 14 and 481 cm². Wounding season and stem DBH had no impact on wound healing. Wound decay incidence correlated positively with the initial width of injury (r = 0.925; P < 0.05). All 1- to 2-cm-wide wounds lacked any decay, while the proportions of decay among 3-, 4-, 5- and 15-cm-wide wounds were 58.3, 50.0, 83.3 and 100%, respectively. Length of decay comprised 35–225 cm. Consequently, wounds on P. abies stems greater than 5 cm width are unlikely to be occluded and more prone to decay development.     

Effect of sulfur-dioxide on protein-SH in needles of Picea abies1

The effect of SO₂ on the SH-groups of proteins in needles of Picea abies is studied. The content of total protein SH and glutathione is estimated with 5.5′-Dithio-bis-nitrobenzoic-acid (Ellman reagent). In addition structural protein SH is measured microspectrophotometrically in sections stained with the SH reagent, mercurochrome. The results indicate that GSH and also total protein SH and structural protein SH are increased in needles of Picea abies growing in SO₂ polluted areas. Compared to needles of trees in relatively unpolluted areas average increases of 2. 33 (GSH), 1.22 (total protein SH) and 1.55 (structural protein SH) are found.     

欧洲云杉嫩枝扦插育苗试验

通过田间试验的方法研究了欧洲云杉嫩枝扦插育苗技术,结果表明:不同土壤、不同扦插时间、ABT生根粉不同浓度及处理时间扦插成活率存在显著差异。其中扦插基质以底层8 cm厚煤渣,上层10 cm厚沙土。扦插时间以7月15~25日为最佳,ADT生根粉处理以100 mg/L处理22 h效果最好,扦插苗60 d后平均愈伤组织产生率88.3%,生根率达79.1%。