Induction of conifer immune responses by phytopathogenic fungus metabolites

The elicitor activity of compounds extracted from the mycelia of six species of phytopathogenic fungi was assessed from the sizes of necrotic lesions on the external surface of the living trunk phloem of five coniferous species inhabiting Siberia: Siberian larch (Larix sibirica L.), Scotch pine (Pinus sylvestris L.), Siberian spruce (Picea obovata Ledeb.), Siberian fir (Abies sibirica L.), and cedar pine (Pinus sibirica (Rupr.) Mayr.). The compounds for inoculation were extracted from the mycelium of ascomycetes imperfect, and basidium fungi; the living mycelia of these fungi were also used. The fungal extract or mycelium was placed into the hollows 7 mm in diameter in the trunk bark. Infection triggered the formation of hypersensitivity necrotic lesions in the inner bark exceeding in size those appeared after control wounding of four tree species (larch, pine, spruce, and cedar); fir was an exclusion. In experiments with tree trunks and conifer calluses, a dependence of immune response parameters (the sizes of necrotic lesions and the content of lignin and bound proanthocyanidins) on the quantity of the fungal preparation was elucidated. The largest necrotic lesions appeared after injection of 500μg of the fungal preparation into the hollow in the trunk, and its higher quantities did not increase the indices measured. The size of the necrotic lesion on the trunk bark is supposed to be used as a promising index characterizing the level of tree immunity and tolerance under various ecological conditions.     

Withdrawn food rate for larvae of Siberian moth on conifers of Siberia

Experimental evaluation of the mass of food withdrawn by larvae of the Siberian moth during their development on larch, cedar pine, fir, spruce, and common pine was carried out. The obtained dependences between the masses of larvae and food withdrawn by them can be directly used to determine the withdrawn food rate of Siberian moth on each of the Siberian conifer species.     

Linking patterns and processes of species diversification in the cone flies Strobilomyia (Diptera: Anthomyiidae)

Phytophagous insects provide useful models for the study of ecological speciation. Much attention has been paid to host shifts, whereas situations where closely related lineages of insects use the same plant during different time periods have been relatively neglected in previous studies of insect diversification. Flies of the genus Strobilomyia are major pests of conifers in Eurasia and North America. They are specialized feeders in cones and seeds of Abies (fir), Larix (larch) ,and Picea (spruce). This close association is accompanied by a large number of sympatric Strobilomyia species coexisting within each tree genus. We constructed a molecular phylogeny with a 1320 base-pair fragment of mitochondrial DNA that demonstrated contrasting patterns of speciation in larch cone flies, as opposed to spruce and fir cone flies; this despite their comparable geographic distributions and similar resource quality of the host. Species diversity is the highest on larch, and speciation is primarily driven by within-host phenological shifts, followed by allopatric speciation during geographical expansion. By contrast, fewer species exploit spruce and fir, and within-host phenological shifts did not occur. This study illustrates within-host adaptive radiation through phenological shifts, a neglected mode of sympatric speciation.     

Antimicrobial and Antiradical Activities of Individual Fractions of Pinus sibirica Du Tour and Abies sibirica Ledeb. Growing in Siberia

Russian Journal of Bioorganic Chemistry - Essential oil from the spruce branches of Siberian pine (Pinus sibirica Du Tour) and Siberian fir (Abies sibirica Ledeb.) growing on the territory of...     

Host shifting by Operophtera brumata into novel environments leads to population differentiation in life-history traits

Abstract.  1. Operophtera brumata L. (Lepidoptera: Geometridae), a polyphagous herbivore usually associated with deciduous trees such as oak Quercus robur L . , has expanded its host range to include the evergreen species heather Calluna vulgaris (L.) Hull and, most recently, Sitka spruce Picea sitchensis (Bong.) Carrière.
2. Phenology, morphology, and survival of O. brumata were measured at several life-history stages in populations from the three different host plant communities sampled from a range of geographical locations. The data were used to test for population differences, reflecting the marked differences in host-plant secondary chemistry, growth form, and site factors such as climate. The hypothesis that spruce-feeding populations originated from populations feeding on moorland, commonly sites of coniferous afforestation, was also tested.
3. Altitude, not host plant species, was the major influence on the timing of adult emergence. An effect of insect population independent of altitude was found, implying that additional unidentified factors contribute to this phenological variation. Larval survival and adult size varied between populations reared on different host plant species. Survival of larvae was affected negatively when reared on the novel host plant, Sitka spruce, versus the natal plant (oak or heather) but oak and heather-sourced insects did not differ in survivorship on Sitka spruce.
4. Host range extension into novel environments has resulted in population differentiation to the local climate, demonstrating that host shifts pose challenges to the herbivore population greater than those offered by the host plant alone. The hypothesis that Sitka spruce feeding populations have arisen predominantly from moorland feeding populations was not supported.     

远东地区影响针叶树天然更新的球果种实害虫———球果花蝇 (双翅目 :花蝇科)( 英文)

球果花蝇是远东地区的重要球果种实害虫。尤其是在我国东北地区 ,由于球果花蝇的危害已严重影响了落叶松种子产量 ,进而影响到落叶松的造林与更新。本文系统地总结了近些年危害落叶松、云杉、冷杉种实的球果花蝇的研究进展及存在的问题。文中还涵括了作者的一些原始研究数据和尚未发表的新结果。     

Comparative dendroclimatic study of Scots pine, Norway spruce, and silver fir in the Vrancea Range, Eastern Carpathian Mountains

Using dendroclimatical methods, we compared the growth response to climate fluctuations of three of the main Romanian Carpathian Mountains coniferous species, Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.) and silver fir (Abies alba Mill.), growing intermixed in a unique stand. Climate and soil conditions were therefore the same for all the trees studied. The experimental site was chosen to be representative of the south-exposed sites in the Romanian Carpathian Mountains, where pine occurs naturally. In order to investigate the consequences of fluctuations in climate at different temporal scales, we examined both inter-annual and decadal time-steps. An index of soil water deficit was computed to investigate the consequences of drought. Our study reveals that species exhibited different responses to precipitation, temperature or drought. Overall, pine was the most sensitive to precipitation, while spruce showed a higher response to temperature at high frequency for both the current and the previous growing seasons, and to soil water deficit. Fir was the least sensitive species of the comparison. However, for all species, decadal modulations of growth show precipitation as a common and strong driver on the dry south-facing slopes. The results show that Scots pine would be affected more than fir by increased drought frequency and could in the future be replaced on the xeric sites.     

How does synchrony with host plant affect the performance of an outbreaking insect defoliator?

Phenological mismatch has been proposed as a key mechanism by which climate change can increase the severity of insect outbreaks. Spruce budworm (Choristoneura fumiferana) is a serious defoliator of North American conifers that feeds on buds in the early spring. Black spruce (Picea mariana) has traditionally been considered a poor-quality host plant since its buds open later than those of the preferred host, balsam fir (Abies balsamea). We hypothesize that advancing black spruce budbreak phenology under a warmer climate would improve its phenological synchrony with budworm and hence increase both its suitability as a host plant and resulting defoliation damage. We evaluated the relationship between tree phenology and both budworm performance and tree defoliation by placing seven cohorts of budworm larvae on black spruce and balsam fir branches at different lags with tree budburst. Our results show that on both host plants, spruce budworm survival and pupal mass decrease sharply when budbreak occurs prior to larval emergence. By contrast, emergence before budbreak decreases survival, but does not negatively impact growth or reproductive output. We also document phytochemical changes that occur as needles mature and define a window of opportunity for the budworm. Finally, larvae that emerged in synchrony with budbreak had the greatest defoliating effect on black spruce. Our results suggest that in the event of advanced black spruce phenology due to climate warming, this host species will support better budworm survival and suffer increased defoliation.     

Small Spruce Bark Beetle Ips amitinus (Eichhoff, 1872) (Coleoptera,Curculionidae: Scolytinae): a New Alien Species in West Siberia

The small spruce bark beetle Ips amitinus is a widespread species in many European countries that has been actively spreading into Northern Europe in the recent decades. In Russia, I. amitinus is present in the western, northwestern, and northern regions of the European part, with a tendency for range expansion. The species was first recognized in West Siberia in 2019 by characteristic morphological features and molecular genetic analysis. This bark beetle is abundant on Pinus sibirica in Siberian pine forests located near settlements within Tomsk and Kemerovo provinces, and is also sporadically found on the Siberian spruce Picea obovata. It colonizes the upper trunk and branches of standing and windfall trees. In the outbreak foci this bark beetle causes catastrophic drying of Siberian pines, starting from the crown top. This pattern of tree drying was noted for the first time near settlements in Yashkinsky District of Kemerovo Province in 2014, and now outbreak foci of I. amitinus exist in all the Siberian pine forests in this district. The population growth of I. amitinus was probably facilitated by dry and hot summer weather in the southeast of West Siberia during the last decade, in 2011 and 2012, and also by heavy winter snowfalls leaving numerous snapped tree branches which are easily colonized by the pest. In Tomsk Province, the most active outbreak focus of I. amitinus appeared in 2018 in the Siberian pine forest near Luchanovo and Ipatovo, following an outbreak of the Siberian moth Dendrolimus sibiricus. The invasion of I. amitinus in Siberia may increase the degradation rates not only of the gene-reserve Siberian pine forests but also of other dark coniferous stands.

     

Changing dynamics of the pine beauty moth (Panolis flammea) in Britain: the loss of enemy free space?

1 The pine beauty moth Panolis flammea has two main host plants in Britain: Pinus sylvestris (Scots pine), which is the ancestral food plant where the insect is never abundant enough to cause tree mortality, and Pinus contorta (lodgepole pine), an introduced host tree that has experienced periodic widespread tree mortality due to this pest.
2 We review the recent literature, published mostly after the year 2000, regarding the impact of natural enemies on the population dynamics of P. flammea in Britain.
3 The natural enemies of P. flammea are more diverse and abundant in Scots pine habitat than in lodgepole pine habitat and some of them show differential selection for P. flammea larvae in Scots pine habitat over those located in lodgepole pine habitat.
4 It is concluded that the difference in the population dynamics of this insect in the two different habitats was probably the result of the P. flammea finding enemy-free space in lodgepole pine habitat.
5 Recent evidence on the diversity and impact of natural enemies on lodgepole pine has demonstrated that they currently have a much more significant impact on this pest than they did in the 1970s and 1980s, when outbreaks were frequent.     

The impact of host plant species on the larval development of the large pine weevil Hylobius abietis L.

• 1 The developmental performance of the large pine weevil Hylobius abietis was studied in the laboratory on four species of conifer, Corsican pine Pinus nigra var. maritima, Sitka spruce Picea sitchensis, Douglas‐fir Pseudotsuga menziesii and Japanese larch Larix kaempferi.
• 2 All species supported development, but, there was considerable variation in larval mortality, development time and weight of adults on emergence between host species.
• 3 Levels of mortality were highest in Japanese larch (77%) and lowest in Corsican pine (8.2%), and the heaviest adults emerged from Corsican pine (130 mg) and the smallest from Douglas‐fir (74 mg).
• 4 A constitutive plant defence chemical, lignin, found to vary within a northern provenance of Sitka spruce, also strongly affected larval development.
• 5 The significance of these findings is discussed in relation to the management of H. abietis.

     

Drought induces lagged tree mortality in a subalpine forest in the Rocky Mountains

Extreme climatic events are key factors in initiating gradual or sudden changes in forest ecosystems through the promotion of severe, tree-killing disturbances such as fire, blowdown, and widespread insect outbreaks. In contrast to these climatically-incited disturbances, little is known about the more direct effect of drought on tree mortality, especially in high-elevation forests. Therefore projections of drought-induced mortality under future climatic conditions remain uncertain. For a subalpine forest landscape in the Rocky Mountains of northern Colorado (USA), we quantified lag effects of drought on mortality of Engelmann spruce Picea engelmannii , subalpine fir Abies lasiocarpa , and lodgepole pine Pinus contorta . For the period 1910–2004, we related death dates of 164 crossdated dead trees to early-season and late-season droughts. Following early-season droughts, spruce mortality increased over five years and fir mortality increased sharply over 11 years. Following late-season droughts, spruce showed a small increase in mortality within one year, whereas fir showed a consistent period of increased mortality over two years. Pine mortality was not affected by drought. Low pre-drought radial growth rates predisposed spruce and fir to drought-related mortality. Spruce and fir trees that died during a recent drought (2000–2004) had significantly lower pre-drought growth rates than live neighbour trees. Overall, we found large interspecific differences in drought-related mortality with fir showing the strongest effect followed by spruce and pine. This direct influence of climatic variability on differential tree mortality has the potential for driving large-scale changes in subalpine forests of the Rocky Mountains.     

不同施水量对云杉幼苗生长和生理生态特征的影响

在中国科学院成都生物研究所茂县生态站,参照云杉分布区的年降水量,设置4种水分处理梯度(分别模拟年降水量为350mm、700mm、1000mm和1350mm),研究云杉幼苗的生长和生理特征差异。经过4a的研究,结果表明,不同施水量显著影响了云杉幼苗的株高、基径、生物量积累(叶重、茎重和根重)、主根长度、第一级侧根数量、气体交换、叶绿素含量、脯氨酸以及丙二醛含量。700mm施水量的云杉幼苗的以上参数显著高于其他3个施水量(350mm、1000mm和1350mm)的幼苗。干旱胁迫下,云杉幼苗净光合速率和蒸腾速率显著降低,抑制了云杉幼苗生物量积累;过量施水则降低了云杉幼苗的根生长。云杉幼苗通过调节水分利用效率来适应不同的水分条件,当受到干旱胁迫时,通过提高水分利用效率来提供生长所需要的水分;然而当水分充足的时候,水分利用效率又降低。此外,水分不足和过量均导致针叶叶绿素含量降低,同时引起丙二醛含量的增加,表明云杉幼苗不适宜在土壤过于干旱和湿润的条件下生长。     

Carabid beetles (Coleoptera: Carabidae) in coniferous plantations in Hokkaido,Japan: effects of tree species and environmental factors

The distribution, species composition and abundance of carabid beetles in monospecific plantations of three different coniferous tree species (Japanese spruce, Sakhalin fir and larch) were investigated by baited pitfall traps in Hokkaido, Japan. In total, 16 150 carabid beetles consisting of 31 species in 13 genera were collected in 2011 and 2012. The most predominant species was Pterostichus thunbergii Morawitz, followed by Synuchus melantho (Bates) and Carabus opaculus (Putzeys). Average numbers of beetles per trap were significantly reduced in larch. Large‐sized Carabus species (C. arboreus arboreus Lewis and C. opaculus) were collected in large numbers in Japanese spruce. There was no significant difference in diversity and equitability among the three kinds of plantation. The ordination of redundancy analysis showed that medium‐sized forest generalists, Pterosticus subovatus (Motschulsky) and P. thunbergii, were highly associated with Japanese spruce and Sakhalin fir, and the forest specialist Synuchus nitidus (Motschulsky) was with Sakhalin fir. In contrast, in larch there was no such associated forest species, and some species of Carabus, Pterostichus and Synuchus were considerably reduced in number, suggesting that larch has unfavorable effects on some forest species. The most important environmental variables influencing carabid assemblages were soil moisture and foliage layer cover. Practices in forest management to minimize the effects of plantations on carabid assemblages are discussed.     

小兴安岭针叶树种在不同尺度上对环境因子的敏感性分析

 小兴安岭地区是我国重要的林区之一,预测该地区针叶树种的分布,在不同尺度上查找针叶树种分布最敏感的环境因子,是不同层次的林业部 门制定森林恢复和植树造林方针的重要科学依据。该文以坡度、坡向、综合地形指数、海拔、坡位指数、年平均温度和年平均降水量作为环境 因子,利用Logistic回归模型对红松（Pinus koraiensis）、兴安落叶松（Larix gmelinii）、冷杉（Abies nephrolepis）、红皮云杉 （Picea koraiensis)、鱼鳞云杉(P. jezoensis)和樟子松（Pinus sylvestris var. mo ngolica）的分布进行了预测。并且采用相对运行特征 (Relative operating characteristic, ROC）,对模型进行了精度评价。其取值范围为0～1, 如果ROC小于0.7,认为模型具有低精度;如 果大于0.7且小于0.9,则模型具有较好的模拟精度;如果大于0.9,认为模型具有很高的预测精度。对每个树种的模型验证表明只有冷杉的ROC 大于 80%,红松、兴安落叶松和云杉的ROC在70%～80%之间,而樟子松的为67.9%。之后,把预测模型应用到丰林保护区,揭示局域尺度上树种 分布最敏感的环境因子。经过树种分布预测图与环境因子之间的相关分析发现,在区域尺度（整个研究区）上,红松、冷杉、云杉和樟子松对 年降水量最为敏感,而兴安落叶松对坡度最敏感。在局域尺度（丰林保护区）上,红松分布对坡度最敏感,冷杉和云杉对海拔最敏感,兴安落 叶松对坡位最敏感。在不同尺度上,树种最敏感的环境因子的转移,引起了在不同尺度上树种分布类型的变化。红松在区域尺度上聚集分布 （ROC=78.6%）,而在局域尺度上其聚集程度有所减弱（ROC=74.4%）,红松的分布范围增加。在区域尺度上,云杉和冷杉聚集分布,但在局域 尺度上,它们的分布接近随机分布类型（ROC<60%）,它们在丰林保护区内分布面积较大。与以上3个树种相反,兴安落叶松的ROC从71.7%增加 到了82.0%,在区域尺度上聚集分布的兴安落叶松,在局域尺度上更加聚集,其分布范围局限于某个特定环境（谷底）。总的来说,在区域尺度 上,多数树种分布对气候因子最为敏感,在局域尺度上,对地理因子最为敏感。不同树种对不同环境因子的敏感性,揭示了树种空间分布格局 和分异规律。     

Cavitation fatigue in conifers: a study on eight European species

After drought-induced embolism and repair, tree xylem may be weakened against future drought events (cavitation fatigue). As there are few data on cavitation fatigue in conifers available, we quantified vulnerability curves (VCs) after embolism/repair cycles on eight European conifer species. We induced 50% and 100% loss of conductivity (LC) with a cavitron, and analyzed VCs. Embolism repair was obtained by vacuum infiltration. All species demonstrated complete embolism repair and a lack of any cavitation fatigue after 50% LC . After 100% LC, European larch (Larix decidua), stone pine (Pinus cembra), Norway spruce (Picea abies), and silver fir (Abies alba) remained unaffected, while mountain pine (Pinus mugo), yew (Taxus baccata), and common juniper (Juniperus communis) exhibited 0.4–0.9 MPa higher vulnerability to embolism. A small cavitation fatigue observed in Scots pine (Pinus sylvestris) was probably biased by incomplete embolism repair, as indicated by a correlation of vulnerability shifts and conductivity restoration. Our data demonstrate that cavitation fatigue in conifers is species-specific and depends on the intensity of preceding LC. The lack of fatigue effects after moderate LC, and relevant effects in only three species after high LC, indicate that conifers are relatively resistant against cavitation fatigue. This is remarkable considering the complex and delicate conifer pit architecture and may be important considering climate change projections.     

The effects of Laccaria proxima and fibrous pulp waste on the growth of nine container-grown conifer seedling species

 Japanese larch (Larix kaempferi), white spruce (Picea glauca), black spruce (Picea mariana), red spruce (Picea rubens), jack pine (Pinus banksiana), mugo pine (Pinus mugo), red pine (Pinus resinosa), Japanese black pine (Pinus thunbergii) and Douglas-fir (Pseudotsuga menziesii var. menziesii), were inoculated to test the effective host range of the ectomycorrhizal fungus Laccaria proxima and the possibility of utilizing pulp waste as a potting medium for containerized seedling production. Laccaria proxima tended to improve the container growth of Japanese black pine and white spruce, and significantly improved that of jack pine, mugo pine, black spruce, red spruce and Douglasfir. The growth of red pine and Japanese larch were only slightly improved with L. proxima. Pulp waste (33% by volume) had negative effects on tree seedling growth, except for Douglasfir (no significant effect). The interactions of Laccaria proxima and pulp waste varied; the hosts were significantly positive (P<0.01) in the case of jack pine and black spruce, but there was no significant effect for the rest. Negative effects were found with Japanese black pine. Use of pulp waste in seedling production of jack pine, black spruce, mugo pine, red spruce and Douglasfir inoculated with L. proxima and of Japanese black pine both with and without L. proxima is feasible, but further research is necessary to determine the optimal percentage of pulp waste that can be utilized in seedling production of tree species and the field performance of these seedlings. Accepted: 30 August 1995     

秦岭东部羚牛越冬栖息地及其特征

1998 年1～4 月, 对牛背梁自然保护区内秦岭羚牛冬季栖息地做了调查研究。结果表明: 该区内共有5 块羚牛冬季栖息地, 呈斑块状分布, 总面积2 305 hm² , 占保护区总面积的14.04 %。羚牛对冬季栖息地选择的关键因子为地形(向阳、背风、相对比较平坦的亚高山台地) 、食物(大宗食物华桔竹和喜食食物杜鹃、腺柳等) 、水源(充足) 、隐蔽而相对较暖的环境(成熟针叶林和针阔混交林) , 以及便于逃避天敌的生境(密生华桔竹林) 。冷杉、华山松等的芽苞和树皮是羚牛冬季必需的食物。冷杉林是该处羚牛分布高度的标志植物和防御风雪寒冷的栖息场所。人类对原生森林植被的破坏, 限制了羚牛的分布及活动范围, 210 国道是保护区内东西两部分羚牛族群间相互扩散的主要障碍。因此促进森林植被的恢复和建立210 国道便于扩散的走廊, 是实现保护区内(尤其是东部地区) 羚牛能够长期生存繁衍十分重要的管理对策。     

Vegetation history of Abies alba Mill. (silver fir) in Switzerland – pollen analytical and genetic surveys related to aspects of vegetation history of Picea abies (L.) H. Karsten (Norway spruce)

This contribution deals with some new aspects of the relationship between the vegetation history of Abies alba Mill. (silver fir) and genetic studies of this tree species in Switzerland. The results of the present study confirm the pollen analytical hypothesis that A. alba re-immigrated into Switzerland mainly from glacial refugia located in northern and central Italy. In particular, some distinct immigration routes of silver fir into the Ticino Alps, Valais, the Bernese Oberland (northwestern Alps), and Graubünden (eastern Alps) could be confirmed by genetic studies. Furthermore, the occurrence of other area-specific alleles indicates an additional influence from eastern European refugia on the Swiss gene pool. Moreover, genetic studies on Picea abies (L.) H. Karsten (Norway spruce) confirmed the general immigration routes from the eastern to the western Alps and from Savoie to the Jura Mountains. The combination of tree pollen and macrofossil analyses of Quaternary sediments with genetic studies of the same tree species represents a considerable research potential and is a new approach of floristic and genetic research. Received November 17, 2000 / Accepted April 27, 2001