[Objective] The aim of this study was to isolate chitinase gene from Trichoderma atroviride strain SS003. [Method] With the aeciospore wall of armandii pine blister rust as inducer, chitinase gene was induced to expre...[Objective] The aim of this study was to isolate chitinase gene from Trichoderma atroviride strain SS003. [Method] With the aeciospore wall of armandii pine blister rust as inducer, chitinase gene was induced to express in Trichoderma atroviride cells. The cDNA fragment of chitinase gene was cloned by RT-PCR approach. [Result] The activity of chitinase induced reached 40.17 μg/10 min; and the specific fragment amplified was 834 bp in length and proved to be the fragment of chitinase gene by sequencing and sequence analysis. [Conclusion] The result showed the feasibility of isolating the full length of chitinase gene and its transformation, and further producing chitinase.展开更多
In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulpe...In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%—90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200—220 ℃ for 60—180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent(RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.展开更多
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 20...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.展开更多
This article summarizes the results of the research papers presented at the International Symposium on pine wilt disease (IUFRO Working Party Meeting 4.04.03) held in July 2009, at Nanjing, China. The general topics...This article summarizes the results of the research papers presented at the International Symposium on pine wilt disease (IUFRO Working Party Meeting 4.04.03) held in July 2009, at Nanjing, China. The general topics covered were on pine wilt disease (PWD), its causal organism, the pinewood nematode (PWN) Bursaphelenchus xylophilus, plus other PWN-associated microorganisms that play a significant role in PWD such as bacteria (e.g. Pseudomonasfluorescens). Most of the papers that are reviewed are based on work on PWD-PWN in East Asia and Russia. Specific topics covered include: 1) the fundamental conceptions of PWD development, 2) pathogenicity, 3) host-parasite relationships including the histopathology of diseased conifers and the role of toxins from bacteria-nematode ecto-symbionts, 4) PWN life cycle and transmission, 5) B. xylophilus dissemination models, 6) associations (with other nematodes), 7) diagnostics, 8) quarantine and control of the PWN and 9) biocontrol of the PWN.展开更多
Korean pine is one of the most important plantation species in northeast China. Besides timber, it produces edible nuts and plantations sequester carbon dioxide from the atmosphere. This study optimized the management...Korean pine is one of the most important plantation species in northeast China. Besides timber, it produces edible nuts and plantations sequester carbon dioxide from the atmosphere. This study optimized the management of Korean pine plantations for timber production, seed production, carbon sequestration and for the joint production of multiple benefits. As the first step, models were developed for stand dynamics and seed production. These models were used in a simulation-optimization system to find optimal timing and type of thinning treatments and optimal rotation lengths. It was found that three thinnings during the rotation period were optimal. When the amount or profitability of timber production is maximized, suitable rotation lengths are 65-70 years and wood production is 5.5-6.0 m(3) ha(-1) a(-1). The optimal thinning regime is thinning from above. In seed production, optimal rotation lengths are over 100 years. When carbon sequestration in living biomass is maximized, stands should not be clear-cut until trees start to die due to senescence. In the joint production of multiple benefits, the optimal rotation length is 86 years if all benefits (wood, economic profits, seed, carbon sequestration) are equally important. In this management schedule, mean annual wood production is 5.5 m(2) ha(-1) and mean annual seed yield 141 kg ha(-1). It was concluded that it is better to produce timber and seeds in the same stands rather than assign stands to either timber production or seed production.展开更多
Previous studies have demonstrated that pine pollen can inhibit cerebral cortical cell apoptosis in mice with arsenic poisoning. The present study sought to detect the influence of pine pollen on apoptosis-related pro...Previous studies have demonstrated that pine pollen can inhibit cerebral cortical cell apoptosis in mice with arsenic poisoning. The present study sought to detect the influence of pine pollen on apoptosis-related proteins. Immunohistochemistry, western blotting and enzyme-linked immunosorbent assays were used to measure the levels of apoptosis-related proteins in the cerebral cortex of mice with arsenic poisoning. Results indicated that pine pollen suppressed cell apoptosis in the cerebral cortex of arsenic-poisoned mice by reducing Bax, Bcl-2 protein expression and increasing p53 protein expression.展开更多
We evaluated seed production in a first-gener- ation orchard of Chinese pine (Pinus tabuliformis) during the crucial transition period from first generation to advanced generations. Clones varied significantly in al...We evaluated seed production in a first-gener- ation orchard of Chinese pine (Pinus tabuliformis) during the crucial transition period from first generation to advanced generations. Clones varied significantly in all traits related to seed production. Repeatability of these traits ranged from 0 to 0.96. Seed production per ramet (SPPR), seed producing index (SPI), the number of relative female strobili (RFS), the number of scales, and the num- ber of ineffective scales had comparatively high repeata- bility at 0.86, 0.87, 0.89, 0.96, and 0.91, respectively. Correlation analysis showed that SPPR was greatly influenced by RFS and by the number of full seeds per cone. Finally, we showed that SPI was the best predictor of the seed-producing ability of clones. Our findings will assist seed orchard managers in effectively predicting and improving seed production of Chinese pine seed orchards.展开更多
Huashan pine (Finus armandii Franch) is a poential species for dendroclimatic study. Ring-width cores were sampled for four stands of two sites from the eastern extreme of the Qinling Mountains. The ring-width chronol...Huashan pine (Finus armandii Franch) is a poential species for dendroclimatic study. Ring-width cores were sampled for four stands of two sites from the eastern extreme of the Qinling Mountains. The ring-width chronologies developed in this study cover a maximum Period from A.D. 1359 t0 1992 and show high common chronology variance over the common period 1911-1960.All the chronologies are significantly correlated with all others, and the degree of correlation appears related to tree age. Response function analyses reveal that from 41 to 75 Percent of chronology variance can be accounted for by monthly mean air temperature and monthly total precipitation. A sufficiently strong correlation of ringwidth index with May and June rainfall and June temperature exists, implying soil moisture to be a limiting factor for Huashan pine growth. The association displayed by response diagrams between narrow rings, low precipitation, and high temperature during spring and early summer indicates a promising potential of ring widths for reconstruction of spring drought for the study area.展开更多
Using the closed chamber technique, the in situ measurements of N2O and CH4 fluxes was conducted in a broad-leaved Korean pine mixed forest ecosystem in Changbai Mountain, China. from June 1994 to october 1995. The re...Using the closed chamber technique, the in situ measurements of N2O and CH4 fluxes was conducted in a broad-leaved Korean pine mixed forest ecosystem in Changbai Mountain, China. from June 1994 to october 1995. The relationships between fluxes (N2O and CH4) and some major environmental factors (temperature, soil water content and soil availabIe nitrogen) were studied. A significant positive correlation between Nzo emission and air/soil temperature was observed, but no significant correIation was found between N2O emission and soil water content (SWC). This result showed that temperature was an important controlling factor of N2O flux. There was a significant correlation between CH4 uptake and SWC, but no significant correlation was found between CH4 uptake and temperature. This suggested SWC was an important factor controlling CH4 uptake. The very significant negative correlation between logarithmic N2O flux and soil nitrate concentration, significant negative correlation between CH4 flux and soil ammonium content were also found.展开更多
This study aimed to demonstrate change in spatial correlation between Korean pine (Pinus koraiensis Sieb. et Zucc.) and three rare species, and change in spatial distribution of four species in response to a range o...This study aimed to demonstrate change in spatial correlation between Korean pine (Pinus koraiensis Sieb. et Zucc.) and three rare species, and change in spatial distribution of four species in response to a range of selective cutting intensities. We sampled three plots of mixed Korean pine and broad-leaf forest in Lushuihe Forestry Bureau of Jilin province, China. Plot 1, a control, was unlogged Korean pine broad-leaf forest. In plots 2 and 3, Korean pine was selectively cut at 15 and 30 % intensity, respectively, in the 1970s. Other species were rarely cut. We used point-pattern analysis to research the spatial distributions of four tree species and quantify spatial correlations between Korean pine and the other three species, Amur linden (Tilia amurensis Rupr.), Manchurian ash (Fraxinus mandshurica Rupr.), and Mongolian oak (Quercus mongolica Fisch.) in all three plots. The results of the study show that selective cutting at 15 % intensity did not significantly change either the species spatial patterns or the spatial correlation between Korean pine and broadleaf species. Selective cutting at 30 % intensity slightly affected the growth of Korean pine and valuable species in forest communities, and the effect was considered nondestructive and recoverable.展开更多
Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Se...Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Seed germination and seedling growth traits at the nursery stage were investigated at the population level. We evaluated relationships between pairs of measured traits as well as the association between measured traits and geo- climatic variables including longitude, latitude, elevation, temperature and precipitation. Seedling growth showed significant differences although a low magnitude of variation was found in the seed germination traits among the populations. Some populations with strong and stable growth (e.g., the Baoshan population) may be selected as superior seed sources for regeneration and reforestation. Germination percentage was negatively correlated with elevation, and positively with precipitation. In addition, germination index, vigor index and seedling height were positively correlated with precipitation. Seed germination index, cotyledon number and length, and seedling diameter were significantly and positively correlated with seed weight. Strong correlations between pairs of traits will be helpful in early evaluations for the selection of certain prominent traits.展开更多
This review summarizes the current state of knowledge on pine and oak forest dynamics in the midmontane central Himalayan forest and the ecosystem services associated with these vegetation types. Forest ecosystems pla...This review summarizes the current state of knowledge on pine and oak forest dynamics in the midmontane central Himalayan forest and the ecosystem services associated with these vegetation types. Forest ecosystems play a crucial role in the livelihood of the central Himalayas as well as the adjacent plains, providing a number of tangible and intangible ecosystem services, at each stage of succession. The successional sequence starts from warm temperate grasslands, followed by early successional pine forests, mid-successional pine-oak mixed forests and eventually culminating in a late successional oak community. This successional sequence is considerably influenced by disturbances like fire, grazing, and lopping, which maintain the vegetation types in their current form and can act as potential drivers of change. Fire and grazing in grasslands and pine forests inhibit the successional process by hindering the establishment of pioneer and late successional species, respectively. Potential land-cover changes with forest succession can lead to changes in ecosystem services supply. We found that the number of ecosystem services associated with these vegetation types increase from early to late successional community. Current management approaches fail to include the dynamic nature of vegetation, which is essential for maintenance of ecosystem service supply. In conclusion, the trade-offs between ES of global (biodiversity and carbon) and local importance (fuel wood and fodder) have to be examined carefully in order to have effective conservation and management plans for the region.展开更多
Large scale harvest of Korean pine (Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endan...Large scale harvest of Korean pine (Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endangered regional ecosystem. Seed collection over past decades greatly reduced the seed bank and subsequent seedling and sapling re- cruitment, and impacting a wide array of granivorous animals that rely on the pine seeds. We surveyed Korean pine seeds, including solid seeds (SS), insect consumed seeds (ICS) and other (animal) consumed (OCS) kernels, of the seed bank (forest floor and the top 10 cm of mineral soil), the seedlings and saplings from 1 m: sample plots in five forest types in Liangshui Nature Reserve (LNR) of the southern Xiao Xing'an Moun- tains in northeastern China to provide accurate information for assessing the Korean pine regeneration potential. The average number of pine seeds in the seed bank were 11.2 seeds/m2, 9.1 seeds/m2, 4.6 seeds/m2, 1.1 seeds/m2, and 0.2 seeds/m2 in Korean pine-basswood forest, mixed Korean pine-hardwood forest, mixed conifer-hardwood forest, white birch forests, and oak forests, respectively. In the first three forest types, percentages of SS (potentially viable seeds) were 11.2%, 3.5% and 27.8%, respectively. The percentages of ICS (not viable seeds) were consistent at around 35%. The higher but variable percentages of OCS (not viable seeds) indicated high seed predation in these forests. Com- pared with other studies, we recorded higher percentages of seed damage, probably due to our survey approach and the increased depth of seed bank sampled in our study. Depletion of pine seeds in the seed bank greatly reduced seedling and sapling recruitment. Densities of pine seed- lings varied from about 180 trees/ha in the mixed Korean pine-hardwood forest to about 5,400 trees/ha in the mixed conifer-hardwood forests and showed a high degree of spatial variation. Saplings were rare in the mixed Korean pine-hardwood forest, but ranged in the thousands in other forests. Large scale pine seed harvest has seriously threatened the sustainability of the mixed Korean pine-hardwood forest ecosystem. Scaling down the seed harvest or supplemental planting of pine saplings are urgently needed to maintain the health of the existing Korean pine forests and to restore this endangered ecosystem.展开更多
Masson pine stands infected by Pine wilt disease(PWD) in the Three Gorges Reservoir Region of central China were surveyed to quantify the immediate responses and subsequent trajectories of biomass,carbon(C),and nitrog...Masson pine stands infected by Pine wilt disease(PWD) in the Three Gorges Reservoir Region of central China were surveyed to quantify the immediate responses and subsequent trajectories of biomass,carbon(C),and nitrogen(N) in stand-level major ecosystem compartments.The biomasses of above-and belowground tree components,as well as of the understory,forest floor,and mineral soil(0–40 cm),were determined within each stand.C and N storage were also estimated for each ecosystem compartment.Overstory biomass decreased steadily with the extent of PWD infection.Understory biomass ranged from1.97 to 4.16 Mg ha,and the observed value for forest floor biomass was 12.89–22.59 Mg ha.The highest mean C and N concentrations were found in the stem bark and needles of Masson pine,respectively,while the lowest were found in the semi-to fully decomposed layer of the forest floor and stem wood of Masson pine,respectively.The C and N storage of aboveground trees,tree roots,and the aboveground ecosystem decreased with the extent ofPWD infection.However,the C and N contents of the understory,forest floor,and total mineral soil initially declined after PWD infection before recovering over the following several years.Those result concluded that the biomass,C,and N storage of different forest ecosystem compartments have experienced certain variations following the PWD epidemic.This is vital to understand the shifts in stand-level C and N allocation in PWD-damaged forest stands,as well as for predicting the responses of regional and global C and N cycling.展开更多
Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtype...Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtypes by numerical cluster analysis. 1) The Pinus sylvestris var. mongolica-Populus davidiana-community was found on relatively dry sites. It was subdivided into a Quercus mongolica-type, consisting of a Adenophora tetraphylla subtype, a Pulsatilla dahurica subtype, and a pure type; 2) The Pinus sylvestris var. mongolica-Rhododendron dauricum-community occurred on medium dry sites. It included a Calamagrostis angustifolia type, consisting of a Cladonia arbuscula subtype, a pure subtype, and a Rubus idaeus-type; 3) The Pinus sylvestris var. mongolica-Ledum palustre-community was found on periodically wet sites. It included a Picea koraiensis type, a Vaccinium uliginosum type, and a pure type.展开更多
Background: Leaf Area Index(LAI) is an important parameter used in monitoring and modeling of forest ecosystems. The aim of this study was to evaluate performance of the artificial neural network(ANN) models to predic...Background: Leaf Area Index(LAI) is an important parameter used in monitoring and modeling of forest ecosystems. The aim of this study was to evaluate performance of the artificial neural network(ANN) models to predict the LAI by comparing the regression analysis models as the classical method in these pure and even-aged Crimean pine forest stands.Methods: One hundred eight temporary sample plots were collected from Crimean pine forest stands to estimate stand parameters. Each sample plot was imaged with hemispherical photographs to detect the LAI. The partial correlation analysis was used to assess the relationships between the stand LAI values and stand parameters, and the multivariate linear regression analysis was used to predict the LAI from stand parameters. Different artificial neural network models comprising different number of neuron and transfer functions were trained and used to predict the LAI of forest stands.Results: The correlation coefficients between LAI and stand parameters(stand number of trees, basal area, the quadratic mean diameter, stand density and stand age) were significant at the level of 0.01. The stand age, number of trees, site index, and basal area were independent parameters in the most successful regression model predicted LAI values using stand parameters(R_(adj)~2=0.5431). As corresponding method to predict the interactions between the stand LAI values and stand parameters, the neural network architecture based on the RBF 4-19-1 with Gaussian activation function in hidden layer and the identity activation function in output layer performed better in predicting LAI(SSE(12.1040), MSE(0.1223), RMSE(0.3497), AIC(0.1040), BIC(-77.7310) and R^2(0.6392)) compared to the other studied techniques.Conclusion: The ANN outperformed the multivariate regression techniques in predicting LAI from stand parameters. The ANN models, developed in this study, may aid in making forest management planning in study forest stands.展开更多
Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m?3 are compared at temperature (T...Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m?3 are compared at temperature (T) ranging from 70°C to 50°C and 5 different relative humidity (RH) conditions. The samples were investigated using the expressate method to follow chromium fixation. Red pine fixes faster than southern pine under all 11 post treatment schedules. The fixation rates for both species are not significantly different while the blocks were fixed under 6 fixation/drying schedules that differed only in the order of T/RH conditions applied. The rate of fixation of all samples in any fixation stage were reduced when the blocks were fixed under lower humidity conditions in spite of no change in chamber temperature. Some of this influence can be attributed to the effect of humidity on heat transfer into the wood and cooling of the wood surface.展开更多
The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turk...The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turks and Caicos Islands(TCI) in just over a decade. Local and international conservation efforts have enabled the necessary multi-disciplinary research, data gathering, and monitoring to develop and implement a restoration strategy for this endemic tree from the Bahaman archipelago. The native plant nursery established on North Caicos and horticultural expertise acquired throughout the years were crucial to the successful rescue of Caicos pine saplings from the wild populations and cultivation of new saplings grown from locally sourced seeds. These saplings have been used to establish six Restoration Trial Plots on Pine Cay and a seed orchard on North Caicos in TCI. Core Conservation Areas(CCAs) for the Caicos pine forests have been identified and mapped. To date, forest within the Pine Cay CCA has been supplemented by planting more than 450 pine trees, which have survived at a high(>80%)rate.展开更多
基金Supported by Science Foundation from Southwest Forestry College(200524M)Natural Science Foundation of Yunan Province(2002C0047M)Key Scientific and Technological Project of Yunan Province(2003NG12)~~
文摘[Objective] The aim of this study was to isolate chitinase gene from Trichoderma atroviride strain SS003. [Method] With the aeciospore wall of armandii pine blister rust as inducer, chitinase gene was induced to express in Trichoderma atroviride cells. The cDNA fragment of chitinase gene was cloned by RT-PCR approach. [Result] The activity of chitinase induced reached 40.17 μg/10 min; and the specific fragment amplified was 834 bp in length and proved to be the fragment of chitinase gene by sequencing and sequence analysis. [Conclusion] The result showed the feasibility of isolating the full length of chitinase gene and its transformation, and further producing chitinase.
基金Supported by the Science and Technology Fund of Fujian Education Departm ent(No.JB 0 2 0 5 8) ,Scientific Develop-ment Fund of Econom y and Trade Comm ission of Fujian Province(No.2 0 0 30 7) ,Science and Technology Department Fund ofFuzhou City(No.
文摘In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%—90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200—220 ℃ for 60—180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent(RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.
文摘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.
基金supportedby a Key Program of the National Natural Science Foundation of China (Grant No. 30430580)the State Forestry Administration of China (Grant No.20070430)a review is done in frames of the project 10-04-01644-a of the Russian Foundation for Basic Research
文摘This article summarizes the results of the research papers presented at the International Symposium on pine wilt disease (IUFRO Working Party Meeting 4.04.03) held in July 2009, at Nanjing, China. The general topics covered were on pine wilt disease (PWD), its causal organism, the pinewood nematode (PWN) Bursaphelenchus xylophilus, plus other PWN-associated microorganisms that play a significant role in PWD such as bacteria (e.g. Pseudomonasfluorescens). Most of the papers that are reviewed are based on work on PWD-PWN in East Asia and Russia. Specific topics covered include: 1) the fundamental conceptions of PWD development, 2) pathogenicity, 3) host-parasite relationships including the histopathology of diseased conifers and the role of toxins from bacteria-nematode ecto-symbionts, 4) PWN life cycle and transmission, 5) B. xylophilus dissemination models, 6) associations (with other nematodes), 7) diagnostics, 8) quarantine and control of the PWN and 9) biocontrol of the PWN.
基金financially supported by the National Natural Science Foundation of China(31600511)the Fundamental Research Funds for the Central Universities of the People’s Republic of China(2572017CA04)
文摘Korean pine is one of the most important plantation species in northeast China. Besides timber, it produces edible nuts and plantations sequester carbon dioxide from the atmosphere. This study optimized the management of Korean pine plantations for timber production, seed production, carbon sequestration and for the joint production of multiple benefits. As the first step, models were developed for stand dynamics and seed production. These models were used in a simulation-optimization system to find optimal timing and type of thinning treatments and optimal rotation lengths. It was found that three thinnings during the rotation period were optimal. When the amount or profitability of timber production is maximized, suitable rotation lengths are 65-70 years and wood production is 5.5-6.0 m(3) ha(-1) a(-1). The optimal thinning regime is thinning from above. In seed production, optimal rotation lengths are over 100 years. When carbon sequestration in living biomass is maximized, stands should not be clear-cut until trees start to die due to senescence. In the joint production of multiple benefits, the optimal rotation length is 86 years if all benefits (wood, economic profits, seed, carbon sequestration) are equally important. In this management schedule, mean annual wood production is 5.5 m(2) ha(-1) and mean annual seed yield 141 kg ha(-1). It was concluded that it is better to produce timber and seeds in the same stands rather than assign stands to either timber production or seed production.
基金supported by the Guangxi Bureau of Traditional Chinese Medicine,No.[2009]73the Department of Science and Technology,Guangxi Zhuang Autonomous Region,No.0640203
文摘Previous studies have demonstrated that pine pollen can inhibit cerebral cortical cell apoptosis in mice with arsenic poisoning. The present study sought to detect the influence of pine pollen on apoptosis-related proteins. Immunohistochemistry, western blotting and enzyme-linked immunosorbent assays were used to measure the levels of apoptosis-related proteins in the cerebral cortex of mice with arsenic poisoning. Results indicated that pine pollen suppressed cell apoptosis in the cerebral cortex of arsenic-poisoned mice by reducing Bax, Bcl-2 protein expression and increasing p53 protein expression.
基金supported by ‘‘the Fundamental Research Funds for the Central Universities(No.2015ZCQ-SW-02)’’ and ‘‘Special Fund for Forestry Scientific Research in the Public Interest(No.201104022)’’
文摘We evaluated seed production in a first-gener- ation orchard of Chinese pine (Pinus tabuliformis) during the crucial transition period from first generation to advanced generations. Clones varied significantly in all traits related to seed production. Repeatability of these traits ranged from 0 to 0.96. Seed production per ramet (SPPR), seed producing index (SPI), the number of relative female strobili (RFS), the number of scales, and the num- ber of ineffective scales had comparatively high repeata- bility at 0.86, 0.87, 0.89, 0.96, and 0.91, respectively. Correlation analysis showed that SPPR was greatly influenced by RFS and by the number of full seeds per cone. Finally, we showed that SPI was the best predictor of the seed-producing ability of clones. Our findings will assist seed orchard managers in effectively predicting and improving seed production of Chinese pine seed orchards.
文摘Huashan pine (Finus armandii Franch) is a poential species for dendroclimatic study. Ring-width cores were sampled for four stands of two sites from the eastern extreme of the Qinling Mountains. The ring-width chronologies developed in this study cover a maximum Period from A.D. 1359 t0 1992 and show high common chronology variance over the common period 1911-1960.All the chronologies are significantly correlated with all others, and the degree of correlation appears related to tree age. Response function analyses reveal that from 41 to 75 Percent of chronology variance can be accounted for by monthly mean air temperature and monthly total precipitation. A sufficiently strong correlation of ringwidth index with May and June rainfall and June temperature exists, implying soil moisture to be a limiting factor for Huashan pine growth. The association displayed by response diagrams between narrow rings, low precipitation, and high temperature during spring and early summer indicates a promising potential of ring widths for reconstruction of spring drought for the study area.
文摘Using the closed chamber technique, the in situ measurements of N2O and CH4 fluxes was conducted in a broad-leaved Korean pine mixed forest ecosystem in Changbai Mountain, China. from June 1994 to october 1995. The relationships between fluxes (N2O and CH4) and some major environmental factors (temperature, soil water content and soil availabIe nitrogen) were studied. A significant positive correlation between Nzo emission and air/soil temperature was observed, but no significant correIation was found between N2O emission and soil water content (SWC). This result showed that temperature was an important controlling factor of N2O flux. There was a significant correlation between CH4 uptake and SWC, but no significant correlation was found between CH4 uptake and temperature. This suggested SWC was an important factor controlling CH4 uptake. The very significant negative correlation between logarithmic N2O flux and soil nitrate concentration, significant negative correlation between CH4 flux and soil ammonium content were also found.
基金funded by China National Science and Technology Support Program(Grant No.2012BAD21B02)
文摘This study aimed to demonstrate change in spatial correlation between Korean pine (Pinus koraiensis Sieb. et Zucc.) and three rare species, and change in spatial distribution of four species in response to a range of selective cutting intensities. We sampled three plots of mixed Korean pine and broad-leaf forest in Lushuihe Forestry Bureau of Jilin province, China. Plot 1, a control, was unlogged Korean pine broad-leaf forest. In plots 2 and 3, Korean pine was selectively cut at 15 and 30 % intensity, respectively, in the 1970s. Other species were rarely cut. We used point-pattern analysis to research the spatial distributions of four tree species and quantify spatial correlations between Korean pine and the other three species, Amur linden (Tilia amurensis Rupr.), Manchurian ash (Fraxinus mandshurica Rupr.), and Mongolian oak (Quercus mongolica Fisch.) in all three plots. The results of the study show that selective cutting at 15 % intensity did not significantly change either the species spatial patterns or the spatial correlation between Korean pine and broadleaf species. Selective cutting at 30 % intensity slightly affected the growth of Korean pine and valuable species in forest communities, and the effect was considered nondestructive and recoverable.
基金supported by the Natural Science Foundation of China(NSFC 31360189 and NSFC 31070591)
文摘Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Seed germination and seedling growth traits at the nursery stage were investigated at the population level. We evaluated relationships between pairs of measured traits as well as the association between measured traits and geo- climatic variables including longitude, latitude, elevation, temperature and precipitation. Seedling growth showed significant differences although a low magnitude of variation was found in the seed germination traits among the populations. Some populations with strong and stable growth (e.g., the Baoshan population) may be selected as superior seed sources for regeneration and reforestation. Germination percentage was negatively correlated with elevation, and positively with precipitation. In addition, germination index, vigor index and seedling height were positively correlated with precipitation. Seed germination index, cotyledon number and length, and seedling diameter were significantly and positively correlated with seed weight. Strong correlations between pairs of traits will be helpful in early evaluations for the selection of certain prominent traits.
文摘This review summarizes the current state of knowledge on pine and oak forest dynamics in the midmontane central Himalayan forest and the ecosystem services associated with these vegetation types. Forest ecosystems play a crucial role in the livelihood of the central Himalayas as well as the adjacent plains, providing a number of tangible and intangible ecosystem services, at each stage of succession. The successional sequence starts from warm temperate grasslands, followed by early successional pine forests, mid-successional pine-oak mixed forests and eventually culminating in a late successional oak community. This successional sequence is considerably influenced by disturbances like fire, grazing, and lopping, which maintain the vegetation types in their current form and can act as potential drivers of change. Fire and grazing in grasslands and pine forests inhibit the successional process by hindering the establishment of pioneer and late successional species, respectively. Potential land-cover changes with forest succession can lead to changes in ecosystem services supply. We found that the number of ecosystem services associated with these vegetation types increase from early to late successional community. Current management approaches fail to include the dynamic nature of vegetation, which is essential for maintenance of ecosystem service supply. In conclusion, the trade-offs between ES of global (biodiversity and carbon) and local importance (fuel wood and fodder) have to be examined carefully in order to have effective conservation and management plans for the region.
基金supported by the National Science Foundation of China (NSFC) grant (grants 30830024,30770330)
文摘Large scale harvest of Korean pine (Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endangered regional ecosystem. Seed collection over past decades greatly reduced the seed bank and subsequent seedling and sapling re- cruitment, and impacting a wide array of granivorous animals that rely on the pine seeds. We surveyed Korean pine seeds, including solid seeds (SS), insect consumed seeds (ICS) and other (animal) consumed (OCS) kernels, of the seed bank (forest floor and the top 10 cm of mineral soil), the seedlings and saplings from 1 m: sample plots in five forest types in Liangshui Nature Reserve (LNR) of the southern Xiao Xing'an Moun- tains in northeastern China to provide accurate information for assessing the Korean pine regeneration potential. The average number of pine seeds in the seed bank were 11.2 seeds/m2, 9.1 seeds/m2, 4.6 seeds/m2, 1.1 seeds/m2, and 0.2 seeds/m2 in Korean pine-basswood forest, mixed Korean pine-hardwood forest, mixed conifer-hardwood forest, white birch forests, and oak forests, respectively. In the first three forest types, percentages of SS (potentially viable seeds) were 11.2%, 3.5% and 27.8%, respectively. The percentages of ICS (not viable seeds) were consistent at around 35%. The higher but variable percentages of OCS (not viable seeds) indicated high seed predation in these forests. Com- pared with other studies, we recorded higher percentages of seed damage, probably due to our survey approach and the increased depth of seed bank sampled in our study. Depletion of pine seeds in the seed bank greatly reduced seedling and sapling recruitment. Densities of pine seed- lings varied from about 180 trees/ha in the mixed Korean pine-hardwood forest to about 5,400 trees/ha in the mixed conifer-hardwood forests and showed a high degree of spatial variation. Saplings were rare in the mixed Korean pine-hardwood forest, but ranged in the thousands in other forests. Large scale pine seed harvest has seriously threatened the sustainability of the mixed Korean pine-hardwood forest ecosystem. Scaling down the seed harvest or supplemental planting of pine saplings are urgently needed to maintain the health of the existing Korean pine forests and to restore this endangered ecosystem.
基金supported by Special Fund for Forest Scientific Research in the Public Welfare(201204501)National Natural Science Foundation of China(31170613)Beijing Higher Education Young Elite Teacher Project(YETP0740)
文摘Masson pine stands infected by Pine wilt disease(PWD) in the Three Gorges Reservoir Region of central China were surveyed to quantify the immediate responses and subsequent trajectories of biomass,carbon(C),and nitrogen(N) in stand-level major ecosystem compartments.The biomasses of above-and belowground tree components,as well as of the understory,forest floor,and mineral soil(0–40 cm),were determined within each stand.C and N storage were also estimated for each ecosystem compartment.Overstory biomass decreased steadily with the extent of PWD infection.Understory biomass ranged from1.97 to 4.16 Mg ha,and the observed value for forest floor biomass was 12.89–22.59 Mg ha.The highest mean C and N concentrations were found in the stem bark and needles of Masson pine,respectively,while the lowest were found in the semi-to fully decomposed layer of the forest floor and stem wood of Masson pine,respectively.The C and N storage of aboveground trees,tree roots,and the aboveground ecosystem decreased with the extent ofPWD infection.However,the C and N contents of the understory,forest floor,and total mineral soil initially declined after PWD infection before recovering over the following several years.Those result concluded that the biomass,C,and N storage of different forest ecosystem compartments have experienced certain variations following the PWD epidemic.This is vital to understand the shifts in stand-level C and N allocation in PWD-damaged forest stands,as well as for predicting the responses of regional and global C and N cycling.
文摘Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtypes by numerical cluster analysis. 1) The Pinus sylvestris var. mongolica-Populus davidiana-community was found on relatively dry sites. It was subdivided into a Quercus mongolica-type, consisting of a Adenophora tetraphylla subtype, a Pulsatilla dahurica subtype, and a pure type; 2) The Pinus sylvestris var. mongolica-Rhododendron dauricum-community occurred on medium dry sites. It included a Calamagrostis angustifolia type, consisting of a Cladonia arbuscula subtype, a pure subtype, and a Rubus idaeus-type; 3) The Pinus sylvestris var. mongolica-Ledum palustre-community was found on periodically wet sites. It included a Picea koraiensis type, a Vaccinium uliginosum type, and a pure type.
基金Funding from The Scientific and Technological Research Council of Turkey(Project No:2130026)is gratefully acknowledged
文摘Background: Leaf Area Index(LAI) is an important parameter used in monitoring and modeling of forest ecosystems. The aim of this study was to evaluate performance of the artificial neural network(ANN) models to predict the LAI by comparing the regression analysis models as the classical method in these pure and even-aged Crimean pine forest stands.Methods: One hundred eight temporary sample plots were collected from Crimean pine forest stands to estimate stand parameters. Each sample plot was imaged with hemispherical photographs to detect the LAI. The partial correlation analysis was used to assess the relationships between the stand LAI values and stand parameters, and the multivariate linear regression analysis was used to predict the LAI from stand parameters. Different artificial neural network models comprising different number of neuron and transfer functions were trained and used to predict the LAI of forest stands.Results: The correlation coefficients between LAI and stand parameters(stand number of trees, basal area, the quadratic mean diameter, stand density and stand age) were significant at the level of 0.01. The stand age, number of trees, site index, and basal area were independent parameters in the most successful regression model predicted LAI values using stand parameters(R_(adj)~2=0.5431). As corresponding method to predict the interactions between the stand LAI values and stand parameters, the neural network architecture based on the RBF 4-19-1 with Gaussian activation function in hidden layer and the identity activation function in output layer performed better in predicting LAI(SSE(12.1040), MSE(0.1223), RMSE(0.3497), AIC(0.1040), BIC(-77.7310) and R^2(0.6392)) compared to the other studied techniques.Conclusion: The ANN outperformed the multivariate regression techniques in predicting LAI from stand parameters. The ANN models, developed in this study, may aid in making forest management planning in study forest stands.
文摘Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m?3 are compared at temperature (T) ranging from 70°C to 50°C and 5 different relative humidity (RH) conditions. The samples were investigated using the expressate method to follow chromium fixation. Red pine fixes faster than southern pine under all 11 post treatment schedules. The fixation rates for both species are not significantly different while the blocks were fixed under 6 fixation/drying schedules that differed only in the order of T/RH conditions applied. The rate of fixation of all samples in any fixation stage were reduced when the blocks were fixed under lower humidity conditions in spite of no change in chamber temperature. Some of this influence can be attributed to the effect of humidity on heat transfer into the wood and cooling of the wood surface.
基金The Meridian ClubPine Cay Homeowners Association for their support to research and restoration efforts on Pine Cay+1 种基金the John Ellerman FoundationDarwin Plus grant (DPLUS016) for financial support for different elements of the overall Caicos Pine Recovery Project between 2014 and 2016
文摘The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turks and Caicos Islands(TCI) in just over a decade. Local and international conservation efforts have enabled the necessary multi-disciplinary research, data gathering, and monitoring to develop and implement a restoration strategy for this endemic tree from the Bahaman archipelago. The native plant nursery established on North Caicos and horticultural expertise acquired throughout the years were crucial to the successful rescue of Caicos pine saplings from the wild populations and cultivation of new saplings grown from locally sourced seeds. These saplings have been used to establish six Restoration Trial Plots on Pine Cay and a seed orchard on North Caicos in TCI. Core Conservation Areas(CCAs) for the Caicos pine forests have been identified and mapped. To date, forest within the Pine Cay CCA has been supplemented by planting more than 450 pine trees, which have survived at a high(>80%)rate.