Effects of peat and weathered coal on the growth of Pinus sylvestrisvar. mongolica seedlings on aeolian sandy soil

The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical prop-erties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. sylvestris var. mongolica seedlings.

Optimum conditions for pure culture of major ectomycorrhizal fungi obtained from Pinus sylvestris var. mongolica plantations in southeastern Keerqin sandy lands, China

The effects of medium, pH, water potential and temperature on the culture for three pure strains （Lactarius deliciosus, Boletus edulis and Lactarius insulsus） of ectomycorrhizal fungi from plantation forests of Mongolian pine （Pinus sylvestris var. mongolica） on sandy lands were observed to obtain the optimum conditions for the growth of ectomycorrhizal fungi. The results indicated that the three ectomycorrhizal fungi could grow well in the mediums containing natural components, such as vitamin, pine juice and yeast powder, pH had a slight effect on the growth of the three ectomycorrhizal fungi, and the optimum pH values were 6.0 for L. deliciosus, 5.0 for B. edulis, respectively. However, L. insulsus had a wide pH range, and it grew better than the other two strains in neutral and light alkalescent mediums. Water potential （produced by Polyethylene Glycol, PEG） had significant effects on the ecological adaptability for the tested three fungi strains. All of the three stains grow better at lower PEG concentration （100 g PEG.kg^-1 H2O）. The best water potential was 10% PEG concentration for all of the three stains. Temperatures, especially high temperatures induced the fungi death. The optimum temperature for the growth of ectomycorrhizal fungi was 25-28℃ for all of the three stains.

Effects of silvicultural treatments on mechanical properties of Pinus sylvestris var.mongolica plantations

A study was conducted to determine the influences of initial planting densities, thinning intensities, exposures and slope sites on physical property （wood density） and mechanical properties such as modulus of elasticity （MOE）, bending strength, impact strength, compression strength along grain and hardness） of Pinus sylvestris var. mongolica plantation in Mao＇ershan Forest Farm, Northeast China. Results show that the different initial planting densities （1.5 m×1.0 m, 1.5 m×2.0 m and 1.5 m×2.5 m） had significant effects on wood density and MOE, and the highest mean wood density and indexes of mechanical properties occurred in the stand with an initial planting density of 1.5 m×1.0 m. The indexes of mechanical properties such as hardness of end, bending strength, MOE and compression strength along grain of wood increased after mild thinning, but decreased after violent thinning. The exposures （sunny slope and shady slope） had a significant effect on MOE, and the highest mean MOE occurred on sunny slope. The slope sites （upper site and lower site） had a significant effect on wood density and main mechanical properties, except hardness. The highest mean wood density and mechanical properties occurred at lower site.

Natural regeneration characteristics of Pinus sylvestris var. mongolica forests on sandy land in Honghuaerji, China

Natural regeneration in Mongolian pine, Pinus sylvesttis var. mongolica, forest at Honghuaerji of China （the original of the natural Mongolian pine, forest on sandy land） was studied in 2004. The total mean values of regeneration indexes were higher in mature stands （more than 80% individual stems were older than 50 years）, the maximum of regeneration index reached 29 seedlings, m^ 2, with lowest values in the younger stand, e.g., in 32-year old and 43-year old stands. The stand age was an important factor determining the natural regeneration, which was the best in the older stands in this investigation （e.g. about 80-year old）. The regeneration index seemed not to be closely in relation to canopy openness although Mongolian pine is a photophilic tree species. In each type of gaps, natural regeneration was very well. Regeneration indexes were satisfactory at the south and east edges in the circle gaps; and at the east edge of the narrow-square gaps. Results indicated that Mongolian pine, seedlings could endure shading understory, but it would not enter the canopy layer without gap or large disturbance, e.g., fire, wind/snow damage or clear cutting etc. These results may provide potentially references to the management and afforestation of Mongolian pine, plantations on sandy land in arid and semi-arid areas. Researches such as the comprehensive comparisons on regeneration, structure and ecological conditions and so on between natural Mongolian pine, forests and plantations should be conducted in the future.

Comparison of foliar nutrient concentrations between natural and artificial forests of Pinus sylvestris var. mongolica on sandy land, China

In order to examine the causes of degradation of Pinus sylvestris var. mongolica plantations on sandy land, the foliar concentrations of N, P, K and C were analyzed and compared between the field grown P. sylvestris var. mongolica trees from two provenances （natural forests and plantations）. The results indicated that natural tree needles had lower N, P and C concentrations, and higher K concentrations than those of plantation tree needles. For plantation tree needles, ratios of N： P, P. K and N： K increased with tree age before 45 years old; but they were not clear for the natural tree needles. Compared with the conclusions reported on Pinus spp., we found that the foliar N and P concentrations were in the optimal range for both natural and plantation tree needles. This result suggested that N or P might not be the absolute limit factors in plant nutrient for P sylvestris var. mongolica on sandy land. However, foliar K concentrations in both natural and plantation tree needles were much lower than those reported on Pinus spp. （〉4.80 g kg-1）.The N： P ratio of natural needles was in the adequate ranges, but N： P ratio of plantation needles was out of the adequate ranges. These results indicated that there was a better balanced nutrition status in the natural forest than in the plantations. If only considering the foliar nutrient concentrations of P sylvestris var. mongolica from different provenances, it might be concluded that the degradation phenomenon of P. sylvestris var. mongolica plantations was not induced by nutrition deficiency of absolute nutrients of N and P, but might be induced by other mineral nutrients or by the effectiveness of N and P nutrients. The unbalanced nutrition status and relatively quick decomposition of needles in the plantations might also contribute to the degradation.

COMPARATIVE STUDY ON DROUGHT RESISTANCE OF LARIX OLGENSIS HENRY AND PINUS SYLVESTRIS VAR.MONGOLICA(Ⅰ)──THE INFLUENCE OF SOIL WATER CONTENT ON SEEDLINGS PLANTING IN FLOWERPOT

Water potential (φ w .) and net photosynthetic rate (Pn) of Larix olgensis and Pinns.sylvestris var. mongolica deercased with the deerease of soil water content φw and Pn of L.olgensis changed hardly during the first 9 davs after stopping watering, then deereased sharply at the 10th dav Pn of P sylvestris var mongolica deereased slightly during the lirst 8 days, then deereased sharply at the 9th day Their respiration rate, chlorophyll content and their a/b ratio changed hardly. The tollowing 3 conclusions were obtained and discussed exhaustively . (Ⅰ) φ w can be used to direct watering as a sensitive index of judging whether L. olgensis and P.sylvestris var. mongolica lacking water (2 )The deereasc of Pn of L. olgensis and P. sylvestris var. mongolica when drought had nothing to do with chlorophyll. (3) P. sylvestris var. mongolica had morphological drought resistance . while L,olgensis had physiological drought resistance, and their drought resistance was discnssed comparatively first time.

Effect of Three Treatment Measures on Harmless Seedling Raising of Pinus sylvestris var.mongolica Litv.

Three treatment measures for raising seedlings by sowing, Le. covering seeds with two layers of forest soil, culturing seedlings under full sunshine and timely sowing in late autumn, were adopted in this study. The results indicated that the three treatments were of good prevention effects on sheath blight or seedling blight, sunscald and rat damage in Pinus sylvestris var. mongolica, could avoid the pollution of agrochemicals to soil and environment as well as decrease cost for raising seedlings, and thus could promote the development of bio-agrochemicals or bio-fungicides with high efficiency and no pollution for resisting the pathogens of sheath blight.

Promoting the Growth of Pinus sylvestris var.mongolica Seedlings and Improving Rhizosphere Fungal Community Structure through Interaction between Trichoderma and Ectomycorrhizal Fungi

In this study,pot experiments were conducted on the seedlings of Pinus sylvestris var.mongolica to study the influence of Trichoderma(Trichoderma harzianum E15)and Ectomycorrhizal fungi(Suillus luteus N94)on the growth of these seedlings.In particular,the effects of these fungi on the fungal community structure in the rhizosphere soil of the seedlings were investigated.Inoculation with Trichoderma harzianum E15 and Suillus luteus N94 significantly(P<0.05)promoted the growth of the Pinus sylvestris seedlings.The non-metric multidimensional scaling(NMDS)results indicated a significant difference(P<0.05)between the fungal community structures in the rhizosphere soil of the annual and biennial seedlings.In the rhizosphere soil of annual seedlings,the main fungi were Ascomycota,Basidiomycota,Zygomycota.Ascomycota,Basidiomycota,Mortierellomycota,and p-unclassified-k-Fungi were the main fungi in the rhizosphere soil of biennial seedlings.The dominant genus in the rhizosphere soil and a key factor promoting the growth of the annual and the biennial seedlings was Trichoderma,Suillus,respectively.Both of them were negatively correlated with the relative abundance of microbial flora in the symbiotic environment.Trichoderma had a significant promoting effect on the conversion of total phosphorus,total nitrogen,ammonium nitrogen,nitrate nitrogen,and the organic matter in the rhizosphere soil of the seedlings,while Suillus significantly promoted the conversion of organic matter and total phosphorus.

Disease Law and Forecasting of the Needle Blight ofPinus sylvestris var. mongolica

Fixed quadrates were established in different stands. In continued six years, the occurring period, occurring amounts and the relation between epidemic disease and environmental factors were investigated according to spraying lawsof spores and accounting measures of disease ranking. The occuring peak period of the disease was from the last ten days ofMay to the second ten days of June. The epidemic period was from the last ten days of June to the second ten days of Julyand the initial decease period was from the last ten days of July to the beginning of September. The change of the diseasedepended on air temperature, relative humidity and precipitation. A multiple linear regression model was established usingcomputer, which can predict the disease index(Y) of 10 days later, with more than 95% reliability

Spatial distribution of needle bright disease of Pinus sylvestris var.mongolica

The spatial distribution pattern of needle bright disease was mathematically studied. The results showed that it is tally with negative binomial distribution. The infected area and damaged amount can be forecasted with this spatial distribution pattern. Through the study on probability distribution of spatial points for single tree, the method and equations for calculation of the disease index of whole forest belt were determined.

Climatic response of Pinus sylvestris var. mongolica tree-ring width and precipitation reconstruction for the northern Greater Higgnan Mountains, China, since 1720

August-June precipitation has been reconstructed back to AD 1720 for the northern Greater Higgnan Mountains, China, by use ofPinus sylvestris var. mongolica tree-ring width. The reconstruction explains the variance of 39% in observed precipitation from 1973 to 2008. Some extremely dry/wet signals in historical documents and other precipitation reconstructions in previous studies are precisely captured in our reconstruction. Wet periods occurred during the periods of 1730 to 1746, 1789 to 1812, 1844 to 1903, 1920 to 1930, 1942 to 1961, and 1985 to 1998; while periods of 1747 to 1788, 1813 to 1843, 1904 to 1919, 1931 to 1941, and 1962 to 1984 were relatively dry. Power spectral and wavelet analyses demon- strated the existence of significant 24-year, 12-year, and 2-year cycles of variability.

Dynamic Simulation of Carbon Sequestration by Pinus sylvestris var. mongolica

Based on the functional process of carbon sequestration of forest, we categorize carbon sequestration in two parts： carbon capture and carbon storage. Here,Pinus sylvestris var.mongolica was used to simulate the dynamic changing process of carbon sequestration of forest in a century using tree growth formula and the cost of carbon capture and sequestration. We found that the total carbon captured and stored by 100-year-old P. sylvestris var.mongolica are both 966 kg C tree^-1. On the assumption that the current year is the planting year, the present total carbon sequestration value （capital value） of 100-year-old P. sylvesrtis var.mongolica is 54.78 USD tree^-1 at the discount rate of 3%, with the present total carbon capture value of 18.92 USD tree^-1 and carbon storage value of 35.86 USD tree^-1. The dynamic process of the annual value of carbon capture is ilustrated by an upside-down U shape curve, while that of carbon storage service folows an S shape curve. The combination of the dynamic processes of carbon capture value and carbon storage value represent the changing process of carbon sequestration value, which appears to be an S shape curve.

沙地樟子松( Pinus sylvestris var. mongolica )物候特征及其对气候的响应

物候反映植被对环境变化的响应。沙地樟子松(Pinus sylvestris var.mongolica)被广泛引种栽植于中国北方风沙区,但引种区气候条件差异对沙地樟子松物候的影响仍然尚不明确。基于2001—2020年MOD13Q1数据和气象数据,分别采用最大斜率法和趋势分析方法提取沙地樟子松植被遥感物候信息并比较物候时空动态特征差异,以偏最小二乘回归方法分析沙地樟子松遥感物候对气象因子变化的响应。结果表明:(1)呼伦贝尔、科尔沁、毛乌素沙地樟子松生长季分别始于第100—150、120—140、100—140天;生长季分别止于第300—340、270—315、260—310天;生长季长度分别为170—220、140—180、150—200 d。(2)呼伦贝尔、科尔沁、毛乌素沙地樟子松生长季始期显著提前(P<0.05),变化率分别为-15.7、-5.7、-13.9 d/10a;科尔沁、毛乌素沙地樟子松生长季末期显著提前(P<0.05),变化率分别为-11.7、-16.8 d/10a;呼伦贝尔沙地樟子松生长季长度显著延长(P<0.05),变化率为9.8 d/10a。(3)呼伦贝尔沙地樟子松生长季始期提前主要受上年8月气温降低和3月降水减少影响,生长季末期提前主要受1月降水减少影响;科尔沁沙地樟子松生长季始期和末期提前分别受上年7月降水减少和5月降水增加影响;毛乌素沙地生长季始期提前主要受3月气温升高和上年12月降水减少影响,生长季末期提前主要受9月气温上升和上年12月降水减少影响。研究结果可为深入理解沙地樟子松物候特征和人工林经营管理提供理论依据。

榆林市樟子松人工林土壤养分特征

为进一步探明陕西省榆林市樟子松人工林的土壤养分变化特征,以5年生樟子松(Pinus sylvestris L. var. mongolica Litv.)纯林和5年生樟子松-胡枝子(Lespedeza bicolor Turcz.)混交林为研究对象,分析土壤有机质、硝态氮、有效磷、速效钾等理化指标以及土壤酶活性的变化特征。结果表明,樟子松纯林和樟子松-胡枝子混交林土壤有机质、有效磷和速效钾含量整体上均随着土层深度的增加呈下降趋势,全磷含量均随着土层深度的增加呈先升高后降低的趋势,硝态氮含量则均随着土壤深度的增加而增加,5个指标均表现为樟子松-胡枝子混交林高于樟子松纯林,且樟子松-胡枝子混交林各层土壤有效磷含量均显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤含水率各土层间差异均不显著,樟子松-胡枝子混交林5~15 cm土层土壤含水率含量显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤碱性磷酸酶活性、过氧化氢酶活性、脲酶活性均随着土层深度的增加而降低,且樟子松-胡枝子混交林过氧化氢酶活性和脲酶活性在各土层均显著高于樟子松纯林(P<0.05)。

Effects of soil moisture and soil depth on nitrogen mineralization process under Mongolian pine plantations in Zhanggutai sandy land, P. R. China

The rates of soil N mineralization at soil depths of 0-15, 15-30, 30-45 and45-60 cm and moisture regimes were measured at three sand-fixation plantations of Pinus sylvestrisvar. mongolica by laboratory aerobic incubation method. The results showed that average rates ofsoil net N-mineralization across soil depth varied from 1.06 to 7.52 mg · kg^(-1)·month^(-1) atsoil depths from 0 to 60 cm. Statistical analyses indicated that the effects of different soildepths, moistures and their interactions on net N-mineralization rates were significant (P < 0.05).The net N-mineralization rates significantly decreased with increasing soil depths and at depth 0-15cm accounted for 60.52% of that at depth of 0-60 cm. There was no difference in soil netN-mineralization rates between half and fully-saturated water treatments, however these rates weresubstantially higher than that without water treatment (P < 0.05). The factors influencing Nmineralization process have to be studied further in these semiarid pine ecosystems.

Soil animals and nitrogen mineralization under sand-fixation plantations in Zhanggutai region,China

The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization.

Natural Mongolian Pine Forests in the Great Xing'an Mountains,Northeast China

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.

Afforestation effects on soil microbial abundance, microbial biomass carbon and enzyme activity in dunes of Horqin Sandy Land, northeastern China

In order to investigate the effects of afforestation on soil microbial abundance, microbial biomass carbon and enzyme activity in sandy dunes, 20-year-old Pinus sylvestris var. mongolica Litv. （PSM） and Populus simonii Carri6re （PSC） mature forests were se- lected in Horqin Sandy Land, and mobile dunes was set as a control （CK）. Results show that PSM and PSC plantations can im- prove soil physicochemical properties and significantly increase microbiological activity in mobile dunes. Soil microbial abun- dance, microbial biomass carbon and enzyme activity show an order of PS〉PSM〉CK. Total soil microbial abundance in PSM and PSC was respectively 50.16 and 72.48 times more than that in CK, and the differences were significant among PSM, PSC and CK Soil microbial biomass carbon in PSM and PSC was respectively 23.67 and 33.34 times more than that in CK, and the difference was insignificant between PSM and PSC. Soil enzyme activity, including dehydrogenase （DEH）, peroxidase （PER）, protease （PRO）, urease （URE） and cellobiohydrolase （CEL） in PSM and PSC were respectively 19.00 and 27.54, 4.78 and 9.89, 4.05 and 8.67, 29.93 and 37.46, and 9.66 and 13.42 times of that in CK. R sylvestris and P. simonii can effectively improve soil physico- chemical and microbiological properties in sandy dunes and fix mobile dunes in Horqin Sandy Land. The Cmic：C ratio is an appli- cable indicator to estimate soil stability and soil water availability, and based on an overall consideration of plantation stability and sustainability, R sylvestris is better than R simonii in fixing mobile dunes in sandy land.

Rhizosphere organic phosphorus fractions of Simon poplar and Mongolian pine plantations in a semiarid sandy land of northeastern China

The aim of this study was to investigate the role of rhizosphere organic phosphorus （P） in soil P supply in semiarid forests and the effects of tree species on rihizosphere organic P. We examined organic P fractions in rhizosphere and bulk soils of mono-specific Simon poplar （Populus simonii） and Mongolian pine （Pinus sylvestris var. mongolica） plantations in a semiarid sandy soil of Horqin Sandy Land in Northeast China. Total organic P （TPo） accounted for 76% of total P across the two stands. The concentration of organic P （Po） fractions decreased in the order of NaOH-Po〉Res-Po〉HCI-Po〉NaHCO3-Po in both plantations. The concentration of NaHCO3-Po was 38% and 43% lower in rhizosphere soil than in bulk soil in Simon poplar and Mongolian pine plantations, respectively. In contrast, total P, TPo and NaOH-Po significantly accumulated in rhizosphere soil in Simon poplar plantations, but no change in Mongolian pine plantations. Soil recalcitrant organic P fractions were positively correlated with soil organic carbon. The results suggest that rhizosphere labile organic P was an important source of plant-available P in this semiarid region, but the dynamic of rhizosphere recalcitrant organic P fractions varied with tree species and was correlated to organic carbon dynamics.

Temperature characteristics of wood during microwave treatments

In order to investigate the temperature characteristics of wood during microwave(MW) treatments,optical fiber sensors were used to measure wood(Pinus sylvestris L. var. mongolica Litv.) temperatures. The results show that the development of internal temperatures in wood basically includes two patterns during the process of MW treatment. The first may be divided into three phases: warming, constant temperature, and a sharply rising phase. The second pattern may be divided into two phases: warming, and constant temperature. The maximum temperature(MT) and rate of temperature increase(RTI)rose as the microwave power increased. The initial wood moisture content decreased while the period of constant temperature fell. Temperatures varied in different positions in the wood. The order of MT and RTI levels were the upper surface, center, bottom surface and the end point.Along the direction of wood thickness, the closer the monitoring point was to the generator, the faster the temperature increased. The MT and RTI of the end point was a minimum value because of the rapid removal of steam.