Modeling the effect of stand and site characteristics on the probability of mistletoe infestation in Scots pine stands using remote sensing data

Over the past decade,the presence of mistletoe(Viscum album ssp.austriacum)in Scots pine stands has increased in many European countries.Understanding the factors that influence the occurrence of mistletoe in stands is key to making appropriate forest management decisions to limit damage and prevent the spread of mistletoe in the future.Therefore,the main objective of this study was to determine the probability of mistletoe occurrence in Scots pine stands in relation to stand-related endogenous factors such as age,top height,and stand density,as well as topographic and edaphic factors.We used unmanned aerial vehicle(UAV)imagery from 2,247 stands to detect mistletoe in Scots pine stands,while majority stand and site characteristics were calculated from airborne laser scanning(ALS)data.Information on stand age and site type from the State Forest database were also used.We found that mistletoe infestation in Scots pine stands is influenced by stand and site characteristics.We documented that the densest,tallest,and oldest stands were more susceptible to mistletoe infestation.Site type and specific microsite conditions associated with topography were also important factors driving mistletoe occurrence.In addition,climatic water balance was a significant factor in increasing the probability of mistletoe occurrence,which is important in the context of predicted temperature increases associated with climate change.Our results are important for better understanding patterns of mistletoe infestation and ecosystem functioning under climate change.In an era of climate change and technological development,the use of remote sensing methods to determine the risk of mistletoe infestation can be a very useful tool for managing forest ecosystems to maintain forest sustainability and prevent forest disturbance.

Ecoregional height-diameter models for Scots pine in Turkiye

Ecoregion-based height-diameter models were developed in the present study for Scots pine(Pinus sylves-tris L.)stands in Turkiye and included several ecological factors derived from a pre-existing ecoregional classification system.The data were obtained from 2831 sample trees in 292 sample plots.Ten generalized height–diameter models were developed,and the best model(HD10)was selected according to statistical criteria.Then,nonlinear mixed-effects modeling was applied to the best model.The R2 for the generalized height‒diameter model(Richards function)modified by Sharma and Parton is 0.951,and the final model included number of trees,dominant height,and diameter at breast height,with a random parameter associated with each ecoregion attached to the inverse of the mean basal area.The full model predictions using the nonlinear mixed-effects model and the reduced model(HD10)predictions were compared using the nonlinear sum of extra squares test,which revealed significant differences between ecore-gions;ecoregion-based height–diameter models were thus found to be suitable to use.In addition,using these models in appropriate ecoregions was very important for achieving reliable predictions with low prediction errors.

Changes in the growth of Scots pine(Pinus sylvestris L.)stands in an urban environment in European Russia since 1862

A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.

Microwave Drying of Scots Pine Lumber:Structure Changes,Its Effect on Liquid Permeability

Microwave(MW)drying method was adopted to enhance the liquid permeability of Scots pine lumber.Structure changes were characterized by stereoscope microscope,scanned electron microscope(SEM)and transmission electron microscope(TEM)examination.Pore parameters before and after MW treatment were detected by mercury intrusion porosimetry(MIP)method,and the effect of structure changes on liquid permeability were analyzed.As stereoscope microscope,SEM and TEM examination results showed,macro and micro checks mainly developed at intercellcular of tracheids,intercellular of ray parenchyma and tracheid,while these checks extend main along the radial-longitudinal plane.Pit border destruction,aspirated pits’orus translocation and micro-checks in tracheid cell wall were also observed.MIP test shown that pore volume and pore area increased as macro and micro checks generated to form new cavities.Microstructure changes would increase the quantity of pores or enlarge the pore diameter.Liquid flow pathways increased as macro and micro checks generated,aspirated pits reopened to form new pathways;liquid flow efficiency improved as porosity,pore volume and pore diameter increased which facilitated the liquid flow.

Response of colour and hygroscopic properties of Scots pine wood to thermal treatment

The effect of heat treatment on the surface colour and hygro- scopic properties of pine wood were investigated in this study. Boards of Scots pine wood （Pinus sylvestris L.） were subjected to thermal treatment at 200℃, for 4, 6, and 8 h. The change of equilibrium moisture content and density values of the specimens in order to facilitate the understand- ing of the treated material behavior. The colour parameters L＊ a＊ and b＊, used to depict the total colour change （dE） of wood surface, were shown to change proportionally to the treatment intensity. Moreover, swelling in the tangential and radial directions and absorption of the specimens ap- peared to be enhanced in great extent by the thermal treatment process. The mean value of swelling percentage in the tangential direction de- creased 10.26%, 17.22%, and 19.60% for specimens treated for 4, 6, and 8 h, respectively, referring to the final measurement after 72 h of immer- sion. In radial direction, mean value of swelling percentage decreased 19.56%, 32.75%, and 34.65% for treated for 4, 6 and 8 h, respectively, after 72 h immersion, which attests the decrease in swelling and im- provement in the hygroscopic behavior of Scots pine wood.

Development and transferability of two multiplexes nSSR in Scots pine(Pinus sylvestris L.)

Single sequence repeat（SSR） multiplexing is a semi high-throughput PCR methodology for the analysis of multiple SSRs.We developed two SSR multiplexes selected from SSR loci previously reported in the pine literature and tested the transferability of both SSR multiplexes in nine other pine species.We tested 234 nuclear SSR loci（n SSRs） previously described in the pine literature and selected ten n SSRs following the simple criteria of interpretability and reproducibility.Selected nuclear loci were divided into two n SSRs multiplex sets and their amplification was optimized for three different multiplex PCR methods based on：（a） a custom PCR protocol,（b） a custom protocol with hotstart taq polymerase,and（c） a commercially available kit for SSR multiplexing.To validate their performance,the level of genetic diversity was assessed in three Scots pine natural populations（Hungary,northern Sweden and southern Sweden）.In addition,we also tested the transferability of these multiplexes in nine other pine species.We have developed two n SSRs multiplexes of five loci each that will contribute to reduce the costs of n SSR scoring,while increasing the capacity of n SSR loci analysis.Amplification was successful in all three populations（94 % success） and the level of polymorphism（7.1 alleles/marker） was similar to that previously reported for other Scots pine natural populations.Transferability of both multiplexes was successful for those pine species closely related to Scots pine.

Longitudinal height-diameter curves for Norway spruce, Scots pine and silver birch in Norway based on shape constraint additive regression models

Background： Generalized height-diameter curves based on a re-parameterized version of the Korf function for Norway spruce （Piceo abies （L.） Karst.）, Scots pine （Pinus sylvestris L.） and silver birch （Betula pendula Roth） in Norwa are presented. The Norwegian National Forest Inventory （NFI） is used as data base for estimating the model parameters. The derived models are developed to enable spatially explicit and site sensitive tree height imputatio in forest inventories as well as future tree height predictions in growth and yield scenario simulations. Methods： Generalized additive mixed models （gamm） are employed to detect and quantify potentially non-linear effects of predictor variables. In doing so the quadratic mean diameter serves as longitudinal covariate since stand ag as measured in the NFI, shows only a weak correlation with a stands developmental status in Norwegian forests. Additionally the models can be locally calibrated by predicting random effects if measured height-diameter pairs are available. Based on the model selection of non-constraint models, shape constraint additive models （scare） were fit tc incorporate expert knowledge and intrinsic relationships by enforcing certain effect patterns like monotonicity. Results： Model comparisons demonstrate that the shape constraints lead to only marginal differences in statistical characteristics but ensure reasonable model predictions. Under constant constraints the developed models predict increasing tree heights with decreasing altitude, increasing soil depth and increasing competition pressure of a tree. / two-dimensional spatially structured effect of UTM-coordinates accounts for the potential effects of large scale spatial correlated covariates, which were not at our disposal. The main result of modelling the spatially structured effect is lower tree height prediction for coastal sites and with increasing latitude. The quadratic mean diameter affects both the level and the slope of the height-diameter curve and both effects are positive. Conclusions： In this investigation it is assumed that model effects in additive modelling of height-diameter curves which are unfeasible and too wiggly from an expert point of view are a result of quantitatively or qualitatively limited data bases. However, this problem can be regarded not to be specific to our investigation but more general since growth and yield data that are balanced over the whole data range with respect to all combinations of predictor variables are exceptional cases. Hence, scare may provide methodological improvements in several applications by combining the flexibility of additive models with expert knowledge.

Scots pine (Pinus sylvestris L.) ecosystem macronutrients budget on reclaimed mine sites—stand trees supply and stability

The aim of this study was to determine the sources, accumulation rate and relationships between macronutrients in reclaimed mine soils (RMS) and aboveground plant biomass on external slopes of lignite mines in central Poland. The study was conducted on two different types of sites with 10-year-old Scots (Pinus sylvestris L.) pine stands located on Quaternary loamy sands (QLS) and on Tertiary acidic carboniferous sands following neutralisation (TCS). The control plot was located in the same vicinity on an external slope in a natural pine ecosystem on a Haplic Podzol in a young mixed coniferous forest habitat (NPE). The nutrient resources, apart from N, were higher in RMS than in comparable Haplic Podzols, however, N primarily accumulated in the mineral horizons. In forest soils, the main macronutrient resources were accumulated in organic horizons, which in natural soils of coniferous forest habitats constitute the main source of nutrients. The proportion of individual macronutrients accumulated in the biomass vs. pools in soil was much lower on the external slope RMS than in the natural site, which in view of the potential richness of RMS, indicated poorer sorption and utilization of macronutrients in aboveground plant biomass than in natural habitats. Other important linear correlations (p = .05) were found between the sources of nutrients in RMS and elements accumulated in biomass (most clearly in case of K, Ca and Mg), which indicates important relationships between soil and vegetation in the first stages of ecosystem development as stimulated by reclamation.

Assessment of early survival and growth of planted Scots pine(Pinus sylvestris) seedlings under extreme continental climate conditions of northern Mongolia

Environmental factors play vital roles in successful plantation and cultivation of tree seedlings.This study focuses on problems associated with reforestation under extreme continental climatic conditions.The objectives were to assess relative seedling performance(survival and growth)with respect to plantation age,and to analyze the influence of specific climatic factors during the early stages of Scots pine(Pinus sylvestris L.)plantations.The study was carried out in reforested areas of the Tujyin Nars region of northern Mongolia on six Scots pine plantations ranging from 5 to 10 years.In each of the six plantations,five 900 m^2 permanent sample plots were established and survival rates and growth performance measured annually over 7 years.Results show high variation in survival among the plantations(p<0.001,F=29.7).Seedling survival in the first year corresponded directly to the number of dry days in May.However,survival rate appeared to stabilize after the second year.The insignificant variation of height categories throughout the observation period indicated low competition among individuals.Two linear mixed-effect models show that height and radial growth were best explained by relative air humidity,which we consider to be a reliable indicator of site-specific water availability.Insufficient amounts and uneven distribution of rainfall pose a major threat during the first year of plantation establishment.Humidity and water availability are decisive factors for a successful seedling plantation.This highlights the impact of drought on forest plantations in northern Mongolia and the importance of developing climate resilient reforestation strategies.

COMPARATIVE ANALYSES ON THE LITTER IN KOREAN PINE MONGOLIAN SCOTS PINE AND DAHURIAN LARCH PLANTATIONS(Ⅱ)CONTENT AND RETURNING AMOUNT OF NUTRIENT ELEMENTS

Comparative analyses were conducted on the nutrient element content and returning amount of main fractional compositions of litter in Korean pine (KP), Mongolian Scots pine(MSP) and Dahurian larch (DL) plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. The results are as follows: (1) The nutrient element content and returning amount in litter varies among different fractional compositions and tree species, the total returning amount of all nutrient elements and the returning amount of K, Ca, Mg, N and P are DL>MSP>KP, the returning amount of Cu is DL>KP>MSP, the returning amount of Fe and Mn are MSP>DL>KP, (2) To KP and DL plantations, the main nutrient element returned is dead needles; dead branches, bark scales and dead cones account for a little proportion; whereas to MSP plantation, besides dead needles,dead branches and bark scales also play an important role in the return of nutrient elements; (3)A little deal of dead leaves can provided a great deal of returning amount of nutrient elements.

AN OBSERVATION OF FORMICA FUKAII WHEELER PREDATORY BEHAVIOR IN MONGOLIAN SCOTS PINE STANDS

The pine sawfly (Acantholyda posticalis Matsumura) is a serious pest of Pinus sylvestris; P. tabulaeformis and P. koraiensis. Chemical control has been generally applied, but caused a lot of problems. We first found Formica fukaii (new record in China). The ants nesting on Carex sp. preying on pine sawflics is an important predator. When nests are removed on purpose, the ant's behavior is normal and the nest are expanded. It is a dominant species and a natural enemy of pine sawfly in Nehe County.

INFLUENCE OF FIRE ON KOREAN PINE AND SCOTS PINE TREES IN PLANTATION

The plantations of korean pine (Pinus koraensis) and scots pine (Pinus sylvesris var. mongolica) are mainly pure stands. Fires are gradually causing problems in these plantations and being paid much more attention recently. Study on the influence of fire on trees and the adaptation to fire, therefore, is of great important to probe the fire ecological properties and the protection ways of these two species. The results are as follows: Both of the species are easily damaged by fire, but korean pine is more susceptible. In the same fire, korean pine is damaged more seriously than scots pine although they have the same size. Young individuals have low fire resistant capacity and can be damaged seriously, and older ones have strong fire resistance and can be damaged lightly. Up-hill fire makes a serious damage to the trees distributed in up-slopes with the reason of higher fire intensity. Down -hill fire makes a serious damage to the trees distributed in down-slopes with the reason of higher fire severity. The larger deocambium area in the tree bark is, the earlier tree growth after fire is. During the early growth stage, the damaged tree bark will Spill over much resin. The height of running resin is higher than that of dead cambium. Damaged trees sprout and grow more slowly and the length of leaves are shorter than these normal trees. The chiorophyll content of serious damaged trees is much higher than that of normal trees. The chiorophyll content of dying trees is 64. 29% higher than that of the contrast ones. Cell membrance penetrability of damaged trees is also higher than that of normal trees.

STUDY ON THE HALF-SIB FAMILY SELECTION FOR THE SUPERIOR TREE OF SCOTS PINE

Investigation and rescarches are carricd out in MaocrshanForcst Farm attached to Northeast Forcstry University in 1988. Comparedwith the contrast, 29 superior familics and 21 inferior families areselected from 112 families of half sib and open pollination of seven-year old scots pine stands by using multicharacters correlations analysis and variance analysis (ANOVA) as well as principal component index (PCI) selection. This index selection which collects multicharacters information has more advantage than monocharacter selection. It is very important to select fine famiIies for buildingthe first generation seed orchard and changing from trial stand toseeding orchard.

COMPARATIVE ANALYSIS ON THE LITTER IN KOREAN PINE MONGOLIAN SCOTS PINE AND DAHURIAN LARCH PLANTATIONS(Ⅰ) AMOUNT AND FLUCTUATION OF LITTER FALL

Investigations were made in korean pine, mongolian scots pine and dahurian larch plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. Data are tabulated on the amount and seasonal and annual nuctuations of fractional composition of the litter (conifer needles, branches, cones, bark scales, broad leaves) in the three plantations. The accounts of conifer needle branch and bark scale litter are as follows: korean pine: 71- 16%, 6. 23% and 7. 32%; mongolian scots pine: 43. 65%, 18. 52 % and 32. 12%; dahurian larch:90. 30%, 7. 83% and 1. 85%. There are certain broadleaf litter in dahurian larch and mongolian scots pine plantations (account for 7. 61% and 8. 92%respectively). The litter wither and fall concent ratively in autumn in dahurian larch plantation and scattered all year long in korean pine and mongolian scots pine plantations. Along with the increase of stand age, the absolute amount of litter tend to increase, the relative amount of main fractional compositions (conifer needle, branch and bark scale) in korean pine and mongolian Scots pine plantations maintain stead, whereas in dahurian larch plantation, the relative amount of conifer needle is decreased gradually and the relative amount of other fractional compositions are increased gradually.

Climate Factors of Vapour Pressure and Diurnal Temperature Influenced on Radial Growth of Scots Pine in Northeastern Mongolia

To find out the optimum conditions of growth in Scots pine (Pinus sylvestris var. mongolica), we analyzed the radial growth response relationship to climate factors in boreal forests. We present growth response from 3-sites Mg (Mangui), KYH (kheyihe), NM (Nanmu) from central Daxing’an mountains. Drought observed in 1920s-1930s years. We analyzed growth response from 1920-2016. Results specified that growth of scots pine did not vary with variation in sites. We measure the influence of vapour pressure and mean maximum and mean minimum diurnal temperature have been shown by correlations of different growing seasons. Most of warm temperature during June to September and growth of Scots pine show a significantly positive increase during winter season. Overall inconsistency in climate conditions of Daxing’an mountains due to Atlantic and Pacific oceans, affects the Asian moon soon and alternatively changes the local temperature and precipitation and vapour pressure and increases the drought severity.

An integrated assessment approach to optimal forest bioenergy production for young Scots pine stands

Background: Bioenergy is re-shaping opportunities and imperatives of forest management. This study demonstrates,through a case study in Scots pine(Pinus sylvestris L.), how forest bioenergy policies affect stand management strategies.Methods: Optimization studies were examined for 15 Scots pine stands of different initial stand densities, site types, and temperature sum regions in Finland. Stand development was model ed using the Pipe Qual stand simulator coupled with the simulation-optimization tool Opti For Bioenergy to assess three forest bioenergy policies on energy wood harvest from early thinnings.Results: The optimal solutions maximizing bare land value indicate that conventional forest management regimes remain optimal for sparse stands. Energy harvests occurred only when profitable, led to lower financial returns. A forest bioenergy policy which included compulsory energy wood harvesting was optimal for denser stands. At a higher interest rate(4 %), increasing energy wood price postponed energy wood harvesting. In addition, our results show that early thinning somewhat reduced wood quality for stands in fertile sites. For less fertile sites, the changes were insignificant.Conclusions: A constraint of profitable energy wood harvest is not rational. It is optimal to carry out the first thinning with a flexible forest bioenergy policy depending on stand density.

Quality of Scots Pine Pollen Depending on the Aerotechnogenic Pollution Level with Emissions from Reftinskiy GRES Power Plant

The aim of the current study was to investigate the process of microgametogenesis and diagnostic of condition of the Pinus sylvestris male generative system in the tree stands exposed to the influence of Reftinskiy GRES power plant (RGpp) emission during ontogenesis in connection with the level of technogenic pollution. It was detected that in the impact area, smoke emissions from the RGpp in the south-west direction zones of technogenic pollution were formed. Those vary in qualitative composition of the snow pack pollutants and their quantitative characteristics. The content of water insoluble compounds in melt snow water and the compile suspended matter, decreases regularly at the longer distance from the source of air pollutants. The highest content of water soluble compounds in the melt snow water was indicated at the distances of 5, 8 and 14 km from the source of air pollutants, authentically lower in the nearest and farthest sampling points of the snow trials. Scots pine (Pinus sylvestris) pollen significative with high prognostic value in relation to the level of toxic load upon the eco-systems and the condition of male generative system were discovered. It was detected that the significative meanings of pollen with morphological abnormalities decreased, and the meanings of functional significatives increased at the longer distance from the source of air pollutants. Pollen fertility, pollen tube length and reserve substances content significative is negatively related to the presence of micro and macro elements in the snow water;those identify the toxic load level on the ecosystem probably to the highest degree. Pine male gametophyte elimination, while forming in the impact zone of the GRES power plant, takes place at the stage of pollen grain germination as well as pollen tubes’ growth stage.

Checking of Radially Sawn Scots Pine and Norway Spruce Wood

In exterior use, wood is subjected to weathering that causes checking and other deterioration in the appearance and technical properties. We studied quantitatively the surface checking of radially and tangentially sawn specimens of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies Karst.) wood in a cyclic climate chamber test. The results strongly suggested that the sawing direction determines the checking performance of both Scots pine and Norway spruce wood. The radial surface of Scots pine specimens had 62% less checks than the tangential one, and the cumulative area of checks was 74% smaller. For Norway spruce, the respective figures were: 83% less in the check number and 91% less in the check area. Different from pine, in spruce specimens the checks of radial surface were significantly smaller. Thus, spruce timber gained clearly more about radial sawing pattern. The effect of annual ring width was similar for pine and spruce: the reduction in annual growth worsened the checking. The increase in density worsened the checking of spruce but did not change the performance of pine. In pine wood, the increase of heartwood proportion reduced the fluctuation of moisture content and the formation of checks.

氯化锌浸渍处理对樟子松热处理材尺寸稳定性和处理能耗的影响

【目的】本研究旨在探究弱酸性氯化锌溶液浸渍对热处理材的尺寸稳定性以及处理能耗的影响。【方法】采用质量分数5%的氯化锌溶液浸渍樟子松试样,并进行不同温度的热处理,通过试样吸湿后的尺寸和质量变化分析,评价浸渍–热处理樟子松试样的尺寸稳定性和吸湿性,并结合红外光谱分析、X射线衍射分析以及能耗计算,阐明浸渍–热处理对试样尺寸稳定性的影响机制和能量消耗情况。【结果】氯化锌浸渍–热处理组的性能提升效果比热处理组更明显;随着热处理温度的升高,木材的吸湿性降低,尺寸稳定性提高,热处理组和浸渍–热处理组的体积湿胀率分别从3.5%、3.4%下降到2.6%、2.1%;两种处理方式下的处理材红外吸收光谱图中均没有产生新的官能团特征峰,但羟基数量均随着温度升高而明显降低;处理材的相对结晶度呈上升趋势,热处理组和浸渍–热处理组分别由36.05%、38.77%提升到48.51%、53.04%;浸渍–热处理组试材在160℃达到的处理效果比仅进行180℃热处理达到的处理效果更好,同时因为前者的处理温度更低,所以能够减少处理过程中的能耗,在所研究的温度范围内最高可减少10%的能耗。【结论】相比樟子松热处理改性,氯化锌浸渍–热处理联合改性可以通过更低的热处理温度使樟子松达到相同的尺寸稳定性,有助于热处理工序的节能减排,对于力学性能方面的影响则需要进一步深入研究。

Stand biomass of Pinus sylvestris var. mongolica plantations benefits from high density monocultures in the boreal zone

Pinus sylvestris var.mongolica(P.sylvestris)plantations are extensively established in the boreal zone.Increasing stand biomass of these plantations can effectively enhance carbon stock,which is crucial for mitigating climate change.However,the current understanding of optimizing plantation strategies to maximize stand biomass is primarily derived from experiments in tropical and subtropical zones,which is difficult to extend to the boreal due to substantial climatic differences.Based on a comprehensive dataset from 1,076 sample plots of P.sylvestris plantations in the boreal zone of China,we evaluated the effects of tree species richness and stand density on tree height,diameter at breast height(DBH),and stand biomass to investigate the optimal plantation strategy.Furthermore,we examined how these effects changed with stand age and investigated their relative importance.We found that monocultures at a high stand density of 2,000–2,500ha^(−1) were the optimal plantation strategy to maximize stand biomass(107.5Mg·ha^(−1)),and this held true at almost all stand ages.Unfortunately,this strategy resulted in low species richness and small individual trees(10.6m height and 9.8cm DBH),thus presenting a trade-off.In addition,as stand age increased,the effect of tree species richness on stand biomass shifted from positive to negative,but the effect of stand density was always positive.Overall,stand age had the greatest effect on stand biomass,followed by stand density and then tree species richness.Our findings reveal a distinct plantation strategy for optimizing stand biomass of P.sylvestris plantations in the boreal zone.More importantly,this study highlights that(1)maximizing stand biomass in the boreal zone may compromise tree species richness;(2)net effects of tree species richness on stand biomass are not always positive,as negative selection effects offset positive complementary effects.