Distribution and variability of n-alkanes in waxes of conifers

Epicuticular waxes have vital roles in the growth and development of plants and in defense. Conifers have a considerable amount of waxes on their cones and leaves.Here we characterized the n-alkane composition of Iranian conifers, including Juniperus oblonga, J. foetidissima, J.sabina, J. communis subsp. hemisphaerica, J. excelsa,Cupressus sempervirens, Platycladus orientalis from Cupressaceae and Taxus baccata from Taxaceae for the first time using GC-FID analyses. In the waxes, 25 n-alkane homologs with chain lengths ranging from C7 to C32 were identified. Short-chain n-alkanes were dominant in almost all samples with some exceptions. Complementary studies to elucidate complete wax constituents of Iranian conifers and n-alkane distribution pattern as a function of geographical and bioclimatic variables are recommended.

In vitro propagation of conifers using mature shoots

Micropropagation mostly leads to the production of innumerable true-to-type plants. However, establishing pathogen-free explants through in vitro culture requires a precise management of time for the exposure of explants to antimicrobial chemicals. The application of antimicrobial chemicals must also be managed to impose the least injury on explants. This review discusses the contributions of micropropagation procedures, explant types, subculture duration, media ingredients and plant growth regulators to the in vitro response of conifer explants. Even though regeneration from mature conifer explants such as mature shoots are laborious, the chances of variation, induced in vitro, are unlikely.

Ectomycorrhizal Fungi of Conifers and Their Economic Value From Xinjiang China

91 noteworthy ectomycorrhizal fungi associated with Larix sibirica Ledeb. etc. from Xing jiang are discussed. Hydnellum caeruleum(Horn. :Pers. )Karst. ,H. peckii Banker apud Peck,Cortinarius azureovelatus Orton,C. pinicola Orton, C. rickenianus Maire are new record to China. Among which 66 species are edible, 14 species are poisonous, 13 species are pharmaceutical, 22 species are probably anticancer.

Warming hiatus-and evergreen conifers in Altay-Sayan Region,Siberia

"Warming hiatus" occurred in the AltaySayan Mountain Region, Siberia in c. 1997–2014. We analyzed evergreen conifer(EGC) stands area(satellite data) and trees(Siberian pine, Pinus sibirica Du Tour, Siberian fir, Abies sibirica Ledeb.) growth increment(dendrochronology data) response to climate variables before and during the hiatus. During the hiatus, EGC area increased in the highlands(>1000 m)(+30%), whereas at low and middle elevations(<1000 m. a.s.l.) the EGC area decreased(-7%). The EGC area increase was observed on the rain-ward northwest slopes mainly. In highlands, EGC area increase mainly correlated with summer air temperature, whereas at low and middle elevations EGC area decrease correlated with drought index SPEI and vapor pressure deficit(VPD). EGC mortality(fir and Siberian pine) in lowland was caused by the synergy of water stress(inciting factor) and barkbeetle attacks(contributing factor). Tree growth increment(GI) dynamics differs with respect to elevation. At high elevation(1700 m) GI permanently increased since warming onset, whereas at the middle(900 m) and low elevations(450 m) GI increased until c. 1983 yr. with followed depression. That GI "breakpoint" occurred about a decade before hiatus onset. In spite of growth depression, during hiatus GI was higher than that in pre-warming period. At high elevation, GI positively responded to elevated June temperatures and negatively to moisture increase(precipitation, root zone moisture content, VPD, and SPEI). At low elevation GI negatively responded to June temperatures and positively to moisture increase. For both, low and high elevation, these patterns persisted throughout the study period(1967–2014). On the contrary, at middle elevations GI dependence on climate variables switch after breakpoint year(1983). Before breakpoint, June air temperature(positive correlation) and moisture(negative correlations) controlled GI. Further temperature increase leads GI depression and switched correlation signs to opposite(from positive to negative with temperature, and from negative to positive with moisture variables).

电镀高饱和磁感应(B_s)CoNiFe软磁薄膜研究

研究了电沉积 CoNiFe 合金薄膜镀液中主盐离子浓度对膜层磁性能的影响。用振动样品磁强计(VSM)和四探针等方法测试分析了膜层的物理性能。结果表明膜层的物理性能与合金镀液中的主盐离子浓度密切相关,镀液中Ni2+、Fe2+、Co2+浓度分别为0.2、0.012和0.063mol/L时,电沉积的 CoNiFe合金膜层的电磁性能较佳。其饱和磁化强度 Bs 达 1.9T,矫顽力Hc 为91.5A/m,电阻率为45μΩ·cm,在 1MHz下磁导率μi 为602。

Intra-and inter-species variations in carbon content of 14 major tree species in Northeast China

Reducing greenhouse gas emissions is one of the major challenges in combating global warming.Carbon,including in the form of carbon dioxide(CO_(2)),is considered an essential greenhouse gas under human control to demonstrate success in emission reductions.However,many carbon stock quantifications in forest ecosystems still rely on the estimated 50%carbon content instead of more precise species-,tissue-and site-specific values.Thus,this study aimed to thoroughly measure and analyze the carbon content and variability using the 14 major tree species in Northeast China.Over 600 trees were destructively sampled from three different major mountainous regions(i.e.,the Changbai,Daxing’an,and Xiaoxing’an mountains),and the carbon contents of each species were precisely measured to the sub-tissue level.Carbon contents varied significantly between species,with foliage carbon mostly found to be the highest,while root carbon contents were the lowest.Average carbon contents can be ranked as:Ulmus laciniata(43.4%)<Phellodendron amurense(43.5%)<Acer mono(43.8%)<Tilia amurensis(44.2%)<Populus davidiana(44.5%)<Fraxinus mandshurica(44.7%)<Juglans mandshurica(44.9%)<Quercus mongolica(45.3%)<Betulla davurica(45.8%)<Betulla platyphylla(46.7%)<Picea koreansis(46.9%)<Larix gmelinii(47.4%)<Pinus koreansis(48.3%)<Abies nephrolepis(48.3%).Carbon contents were higher in conifers(47.7%)compared to broadleaf species(44.9%).In addition,both tree tissues and growing sites also had a significant effect on carbon content.At the sub-tissue level,only stem’s sub-tissues(i.e.,bark,heartwood,and sapwood)carbon contents showed significant variations.The results suggest that bark should be separated from other stem sub-tissues and considered separately when determining carbon stocks.This research contributes to improving estimates of terrestrial carbon quantifications,and in particular,the values obtained can be used in China’s National Forest Inventory.

Ectomycorrhizal diversity at five different tree species in forests of the Taunus Mountains in Central Germany

Ectomycorrhizal fungi were investigated on five different forest tree species growing in pure stands on the south slope of the Taunus Mountains, which are situated at the northern end of the Rhine rift valley in Central Germany. Mycorrhizal fungi accompanying the genus Xerocomus were identified and their frequencies counted. Using ITS markers, 22 different fungal species were identified down to species level and 6 down to genus level. On European beech (Fagus sylvatica) 16 fungal species and 4 genera were identified and on Sessile oak (Quercus petraea) 16 ectomycorrhizal species and 2 genera were determined. On both deciduous trees we observed exclusively: Cortinarius subsertipes, Genea hispidula, Lactarius quietus, Tylopilus felleus and a Melanogaster genus. On Norway spruce (Picea abies) we identified 13 different mycorrhizal species and 3 different genera, on Silver fir (Abies alba) 12 species and 3 genera, and in association with European larch (Larix decidua) 11 species and 3 genera. On these conifers Cortinarius anomalus, Lactarius necator and a Piloderma genus occurred exclusively. Comparisons with published data of ectomycorrhizal diversity on the same five tree species, growing in different areas of Germany and Europe, led to the conclusion that there is relative site specificity for ectomycorrhizal communities. Upper soil compartments of the stands investigated in the Taunus Mountainssuffer from soil acidification (pH-H20 ~3.7 to ~4.8). However, a clear correlation between upper soil pH-values and fungal diversity was not observed. On the other hand, nitrate concentrations in upper soil compartments (~26 to ~91 kgNO3-/ha) were higher in older stands as compared to younger ones. Higher nitrate concentrations in upper soils correlated with lower numbers of mycorrhizal individuals.

Evaluating and quantifying the effect of various spruce budworm intervention strategies on forest carbon dynamics in Atlantic Canada

Spruce budworm (SBW) outbreaks are one of the most devastating natural disturbances in spruce-balsam fir forests of eastern North America. Both early intervention strategy (EIS) and foliage protection strategy (FP) are being tested to limit forest losses, but the quantitative impact on forest carbon (C) dynamics is still unclear. In this study, we designed 19 separate scenarios of no intervention or varying success of EIS, FP, and their combination on SBW caused defoliation and mortality. We then used the TRIPLEX-Insect model to quantify their effects on forest C dynamics in the forests of the four provinces of Atlantic Canada. A scenario applying FP to 10%of the area with the greatest potential C losses of living biomass, protecting foliage in 10%of the forests is more realistic than higher proportion of FP given the high cost and large areas involved, resulted in reducing average cumulative net ecosystem productivity (NEP) from 2020 to 2039 by 56%–127%compared to a no outbreak scenario.Our results showed that FP would have to be applied everywhere to reduce tree mortality and increase NEP more than 8 years of successful EIS applied. However, if EIS can be successfully implemented for 12 years, it will maintain more forest C than FP applied everywhere during a moderate outbreak. We also found that the combination of EIS followed by FP in 10%of the areas disturbed by the SBW could maintain average cumulative NEP at similar levels to no defoliation in every province of Atlantic Canada. Black/red spruce forests younger than 60years old underwent the smallest changes in C dynamics whether using EIS, FP, or both. This highlights the importance of forest species, forest age, and their interactions on the effectiveness of a treatment during SBW outbreak. Overall, 31%–76%of the study area in Atlantic Canada could convert from a C sink to a source by 2039,if no protective measures are used under the worst-case scenarios, thus contributing to future climate warming.

Stand age structural dynamics of conifer, mixedwood, and hardwood stands in the boreal forest of central Canada

To study the effects of stand development and overstory composition on stand age structure, we sampled 32 stands representing conifer, mixedwood, and hardwood stand types, ranging in ages from 72 to 201 years on upland mesic sites in northwestern Ontario. We defined the stages of stand development as: stem exclusion/canopy transition, canopy transition, canopy transition/gap dynamics, and gap dynamics. Stand age structure of conifer stands changed from bimodal, bimodal, reverse-J, and bimodal, respectively, through the stages of stand development. Mixedwood and hardwood stands revealed similar trends, with the exception of missing the canopy transition/gap dynamic stage in mixedwoods. Canopy transition/gap dynamic stage in hardwoods showed a weaker reverse-J distribution than their conifer counterparts. The results suggest that forest management activities such as partial and selection harvesting and seed-tree systems may diversify standard landscape-level age structures and benefit wildlife, hasten the onset of old-growth, and create desired stand age structures. We also recommend that the determination of old-growth using the following criteria in the boreal forest: 1) canopy breakdown of pioneering cohort is complete and stand is dominated by later successional tree species, and 2) stand age structure is bimodal, with dominating canopy trees that fall within a relatively narrow range of age and height classes and a significant amount of understory regeneration.

Late Triassic flora of the northern part of the Fore-Caspian depression(Kazakhstan)as exemplified by data from the S.Nurzhanov-509 borehole

The Late Triassic Nurzhanov flora is characterized on the basis of the material originated from the S.Nurzhanov-509 borehole disposed in the northern part of the Fore-Caspian depression,near the City of Atyrau,Republic of Kazakhstan.Taxonomic composition of the Nurzhanov flora includes equisetophytes Neocalamites sp.,ferns Phlebopteris hazarensis Naugolnykh et Pronin,Todites sp.,Cladophlebis sp.,ginkgophytes Ginkgoites spp.,conifers Podozamites sp.Palaeophytogeographic status of the Nurzhanov flora is discussed.According to the data obtained,this flora belongs to a transitional zone(an ecotonous belt),which existed between the Euro-Sinian and the Siberian-Canadian palaeofloristic realms during most of the Mesozoic time.

Forest Reproductive Material and Conservation of Forest Genetic Resources in Croatia

Conservation of genetic diversity of forest tree species represents the foundation for sustainable forest management and preservation of natural structure of forest stands in Croatia. Diversity of geographical regions in Croatia has generated various ecological conditions and thus diverse forest communities which are directly affected by habitat degradation, various anthropogenic effects like pollution of air and water, excessive use of certain more valuable species of forest trees and by the increasing impact of global climatic changes. The need for conservation of genetic diversity is related to the species pertaining to social broadleaves—the prevailing species in terms of economic utilization as Pedunculate Oak (Quercus robur), Sessile Oak (Quercus petraea) and Common Beech (Fagus sylvatica). Among the conifers Silver Fir (Abies alba) is the most endangered species, with more than 70% of its population being seriously damaged. Other native coniferous species must be preserved from a decrease in genetic diversity as well. Conservation of the noble broadleaves should encompass a larger number of species from various genera (Fraxinus, Alnus, Ulmus, Prunus, Juglans, Castanea, Sorbus, Acer, Malus, Pyrus, Tilia). These are partially endangered because of their exposure to different pests and diseases, as well as by permanent exploitation due to their technical value. Changes in hydrological conditions of rivers have led difficulties in regeneration of the riparian forests and decreased the genetic variability of European Black and White Poplar in their habitats (Populus nigra, P. alba). In Croatia’s Adriatic coastal areas, there is a need for conservation of genetic resources of Dalmatian Black Pine (P. nigra ssp. dalmatica) and Mediterranean Oaks (Quercus ilex, Quercus pubescens). Conservation of genetic diversity of various forest tree species is conducted within the programmes that include in situ and ex situ methods with ensuring quality forest reproductive materials. In Croatia, a total of 125 seed stands have been selected, covering a total area of 3885.53 ha. The ex situ method is implemented by establishment of a total of 50 plots (clonal seed orchards, provenances and progeny trials, clonal archives), covering 114.85 ha.

Siberian silkmoth outbreaks surpassed geoclimatic barrier in Siberian Mountains

Siberian silkmoth(SSM,Dendrolimus sibiricus Tschetv.)is the most important defoliator of Siberian pine(Pinus sibirica Du Tour)and fir(Abies sibirica Ledeb.)stands.Warming-induced SSM outbreaks are one of the major driving factors of successions within the taiga zone.It is suggested that climate change impacted the SSM range and life cycle.We analyzed the migration of alpine and northerly SSM outbreak boundaries in Siberia and the impact of the climate variables and topography on the outbreak dynamics.We used time-series scenes(multispectral data,and vegetation indexes EVI and NDII)in combination with field studies,climate variables,and GIS techniques.We found that SSM outbreaks in the area of alpine boundary shifted about 370 m uphill since the mid of 1950.The outbreak onset was promoted by increased dryness and active temperatures and decreased root zone moisture content in the spring-early summer period.The terrain topography strongly affected SSM outbreak onset and dynamics.Initially,the outbreak was located at the middle elevations on the gentle concave southeastern slopes,which are the favorable insect habitats between outbreaks.Then the outbreak expanded uphill and downhill,to steeper slopes,and both concave and convex terrains.Alongside with elevation range expansion,SSM surpassed its northern historical outbreak boundary:the potential outbreaks’boundary moved about 300 km northward.Climate warming contributes to SSM migration into former outbreak free conifer stands located in highlands and at northern latitudes.

Electrodeposition behavior of nanocrystalline CoNiFe soft magnetic thin film

The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density (Bs>2.1 T) and low coercivity (Hc) was investigated using cyclic voltammetry and chronoamperometry methods in conjunction with the scanning electron microscopy (SEM/EDX). The results show that, under the experimental conditions, the co-deposition of CoNiFe film behaves anomalously due to the atomic radii of iron series elements following the order of rFe>rCo>rNi. In the case of lower electroplating current density, the co-deposition of CoNiFe film follows a 3-D progressive nucleation/growth mechanism, while in the case of higher electroplating current density, which follows a 3-D instantaneous nucleation/growth mechanism. Meanwhile, the change of nucleation mechanism of CoNiFe film with electroplating current density was interpreted theoretically in the light of quantum chemistry.

Local and generalized height-diameter models with random parameters for mixed,uneven-aged forests in Northwestern Durango,Mexico

Background:We used mixed models with random components to develop height-diameter(h-d) functions for mixed,uneven-aged stands in northwestern Durango(Mexico),considering the breast height diameter(d) and stand variables as predictors.Methods:The data were obtained from 44 permanent plots used to monitor stand growth under forest management in the study area.Results:The generalized Bertalanffy-Richards model performed better than the other generalized models in predicting the total height of the species under study.For the genera Pinus and Quercus,the models were successfully calibrated by measuring the height of a subsample of three randomly selected trees close to the mean d,whereas for species of the genera Cupressus,Arbutus and Alnus,three trees were also selected,but they are specifically the maximum,minimum and mean d trees.Conclusions:The presented equations represent a new tool for the evaluation and management of natural forest in the region.

The importance of willow to the Chinese Grouse:evidence from analysis on their breeding territories at Lianhuashan,China

Background: The habitat features of breeding territory have important adaptive significance for the survival and reproduction of territory holders.The Chinese Grouse(Tetrastes sewerzowi) is a rare and endemic species with rela?tively small distribution range and decreasing population trend.It is important to elucidate breeding territory habitat requirements of the Chinese Grouse for habitat management and conservation actions.Methods: Using radio?telemetry and field observations,we determined the core areas of 65 breeding territories of males.Two to three samples were selected in each core breeding territory as used sites and compared with nearby sites with no grouse occurrence using logistic regression.Results: Our model showed a high accuracy in prediction of core breeding territory used by males,which preferred stands with more small deciduous trees(0.5 m ≤ height < 5 m),more small willow trees(Salix spp.,0.5 m infl≤ height < 5 m),greater willow cover,and greater herb cover.The number of small willow trees had the great?estuence on males' core breeding territory selection.Dense shrubs were also chosen compared with unused sites Tall conifer trees was an important determinant in the distribution of Chinese Grouse at the landscape scale,and was relatively important in the univariate model,but not included in our final multivariable model.Conclusions: Male Chinese Grouse established territories at sites with abundant food resources.At the landscape scale,the Chinese Grouse occurred in alpine conifer forest.At the territory scale,small willow trees had the most important effect on males' core breeding territory selection.We suggest that the forest gaps in dense conifer for?est are important for improving the occurrence of willows and facilitating breeding territory establishment for the Chinese Grouse.

Impacts of Coriaria nepalensis colonization on vegetation structure and regeneration dynamics in a mixed conifer forest of Indian Central Himalaya

This study evaluated impacts of Coriaria nepalensis Wall.colonization on soil characteristics,vegetation structure and composition,regeneration status and expected future compositional changes,biomass and carbon stock in tree species of a mixed conifer forest of Central Himalaya.Three sites(1 ha each in an old landslide area)differing in Coriaria density(low:20 individuals ha^(-1);medium:120 indiv.ha^(-1);high:190 indiv.ha^(-1))were used to enumerate the tree species.A total of 9 tree species and 2830 individuals were recorded from the three study sites that represented a gradient of Coriaria density.Number of species varied from 3 to 7 and the individuals from 690 to 1270 per site with lowest numbers at low Coriaria density and highest at medium Coriaria density.The number of seedlings increased with increasing Coriaria density,and the sites were unique in their seedling composition,indicating marked temporal dynamics.Site wise regeneration analysis showed that regeneration was poor at the site with low Coriaria density and good at the high-density site where many species emerged as seedlings.These results indicate that the ameliorative effects of Coriaria in terms of soil buildup,and accumulation of nutrients and organic matter helped more species to colonize the area.This facilitative ability of Coriaria can be used to restore degraded forest ecosystems of Indian Central Himalaya.

A Study of Collecting Robot of Conifer Cone

The collecting robot of conifer cone mainly consists of walking mechanism and manipulator. Manipulator has 5 freedoms. The main technical parameters of this robot are as follows :maximum height of collecting is 14m, maximum radius of collecting is 68m, velocity of collecting is 0.65 m/s, and the maximum force of collecing is 2500N.

Vegetation-environment relationship in conifer dominating forests of the mountainous range of Indus Kohistan in northern Pakistan

Environmental variables play a crucial role in shaping vegetation structure,mainly in mountainous ecosystems.Different studies have attempted to identify the environment-vegetation relationship of Conifer Dominating Forests(CDF)worldwide.However,due to differences in local climate and soil composition,different environmental drivers can be found.By applying multivariate analysis techniques,this study investigated the vegetation-environment relationship of CDF of Indus Kohistan in northern Pakistan.Our results showed that CDF of Indus Kohistan are distributed in five distinct ecological groups,which are dominated by different trees and understory species.A total of 7 trees and 71 understory species were recorded from the sampling sites.Cedrus deodara was the leading species among four groups,having the highest importance value(IV),density and basal area.Group I was dominated by Pinus wallichiana with the second highest importance value,density and basal area.In addition,elevation,slope,maximum water holding capacity(MWHC),soil moisture(SM),total organic matter(TOM),sodium,phosphorus and nickel showed highly significant influence on composition and distribution pattern of Indus Kohistan vegetation.Therefore,this study shows a new evidence of vegetation-environment relationship,pointing out specific drivers of vegetation structure in CDF of Indus Kohistan region in northern Pakistan.

EFFECTIVENESS OF ACEPHATE IMPLANTS IN PROTECTING CONES FROM INSECT DAMAGE IN SOME CONIFERFORESTS OF NORTHEASTERN CHINA

Stem implants of acephate were tentatively used to contfol cone and seed insects in Northeastern China in 1993. Experiments considered in a Siberian larch seed orchard and mother-tree stands of Korean pine and Korean spruce that promising control of major cone pests, including cone tlies, cone-worms and seed-worms, was obtained in all of the conifer species but treatment did not reduce significantly damage due to seed chalcids. Acephate implants did not seem to affect seed germination.

STATISTICAL ANALYSIS OF TEMPERATURES ON BOTH THE UPPER AND LOWER BOUNDARIES OF SUB－ALPINE DARK CONIFER FORESTS IN CHINA

Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these estimated data, the heat factors to influence and control the distribution and growth of subalpine dark conifer forests in China are discussed. It is found that the most important heat index to influence and control the distribution and growth of subalpine dark conifer forests is neither the mean temperature in the warmest month, nor the maximum or minimum temperatures, but monthly accumulated temperature of>0℃ or monthly effective accumulated temperature of>5℃.When monthly accumulated temperature of>0℃ is more than 40℃, or monthly effective accumulated temperature of>5℃ is over 50℃, sub-alpine dark conifer forests cannot grow well. When monthly accumulated temperature of>5℃ is less than 60℃, sub-alpine dark conifer forests can not grow at all. When monthly effective accumulated temperature of>5℃ is in the range 15℃-45℃, subalpine dark conifer forests in China can grow well. The ecological significance of temperature in May and September, and in summer half year are discussed.