Mongolian pine is an important afforestation species widely used for ecological management in northeast China. The environment in this region is very unstable and the flora are regularly subjected to drought stress.Th...Mongolian pine is an important afforestation species widely used for ecological management in northeast China. The environment in this region is very unstable and the flora are regularly subjected to drought stress.This paper reports on the influence of inoculation with the Suillus luteus on seedlings under different water conditions.Both inoculated and non-inoculated ectomycorrhizal fungi(ECMF)-S. luteus seedlings were maintained under wellwatered or water-stress conditions for 3 months. The S.luteus colonization rate under water stress was higher than that in well-watered conditions. Under water stress, inoculated seedlings had greater growth than non-inoculated seedlings. In addition, under water stress, S. luteus-inoculated seedlings had greater superoxide dismutase and peroxidase activity, higher soluble protein content, lower proline content, and lower malondialdehyde content than non-inoculated seedlings. S. luteus colonization increased the rhizosphere soil-enzyme activity and the rhizosphere soil nutrition content under both well-watered and water-stress conditions. Given the positive impact on seedling growth and physiology, S. luteus shows potential for use in the arid and semi-arid regions of northeast China for afforestation.展开更多
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 fi...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.展开更多
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 growt...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.展开更多
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 wit...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.展开更多
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...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.展开更多
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 v...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.展开更多
This research investigates the mechanism of increased salinity tolerance of ectomycorrhizal fungiinoculated P. sylvestris var. mongolica to provide a theoretical basis for the application of the fungus in saline soils...This research investigates the mechanism of increased salinity tolerance of ectomycorrhizal fungiinoculated P. sylvestris var. mongolica to provide a theoretical basis for the application of the fungus in saline soils.Growth effects due to inoculation of seedlings with Suillus luteus(a symbiotic ectomycorrhizal fungus), were determined in four kinds of saline–alkali soils. Growth and physiological indicators, including photosynthetic characteristics, plant height, biomass, photosynthetic pigments,catalase(CAT) and superoxide dismutase(SOD) enzyme levels, and malondialdehyde(MDA), an organic marker for oxidative stress, and soluble protein levels were determined. Mycorrhizal colonization rate decreased with increasing saline–alkalinity and growth of inoculated seedlings was significantly enhanced. Biomass and chlorophyll contents also increased significantly. SOD and CAT activities were higher than in non-inoculated seedlings. However, MDA content decreased in inoculatedseedlings. Soluble protein content did not increase significantly. Inoculation with a symbiotic ectomycorrhizal fungus could enhance the saline–alkali tolerance of P. sylvestris var. mongolica. Growth and physiological performance of inoculated seedlings were significantly better than that of uninoculated seedlings. The results indicate that inoculated P. sylvestris var. mongolica seedlings may be useful in the improvement of saline–alkali lands.展开更多
This paper summarizes the result from the provenance test of eight years old Pinus sylvestris var. mongolica in Liangshui Natural Rcserve comprehensivcly. The main contents include:(1) the geographic variation of the ...This paper summarizes the result from the provenance test of eight years old Pinus sylvestris var. mongolica in Liangshui Natural Rcserve comprehensivcly. The main contents include:(1) the geographic variation of the growth characters of Pinus sylvestris var.mongolica.tends to negative change gradually at latitude and has obvious climatic nature, (2) no significant difference exists in the morphological adaptability and resistant characteristics and so on; (3)on the basis of the geographic variation study on the growth characteristics, the provcnances of Pinus sylvestris var. mongolica were classificd into two geographic populations and two subpopulations as follows:the northern population of the Daxing'an Mountain (Ⅰ) and the southern population of the Daxing'an Mountain as wcll as the Xiaoxinglan Mountain (Ⅱ),which includcs Honghuarii subpopulation and Kalunshan subpopulation (Ⅱ-2). (4) the height growth rhythm was analyzed according to the divided population and subpopuIation; (5) the best provcnance was selected for the Liangshui Natural Rescrve and its neighborhood accord ing to the results from SSR test of the growth characteristics (the breast height diameter and height of eight year old trces), the possibility of the carly provcnance sclection was also verified by the method of order correlation analysis on the height growth of three. five, scvcn and eight years old provenances.展开更多
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 ...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展开更多
The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary pro...The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed.The regressive equation for the estimation of each organ biomass was established through djmensional analysis.Preferable equation with higher precision was selected. The study results showed that the total biomass of theforest community was 62.023 t/hm2 and net primary production was 5.045 V(hm2. a). which indicates that thecommunity of plantation possesses high bio-productivity.展开更多
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...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)。展开更多
To find out the Xylem anatomical variations we analyzed the cell structure, lumen area early wood, lumen area late wood, ring width growth response relationship to climate factors in boreal forests. We present growth ...To find out the Xylem anatomical variations we analyzed the cell structure, lumen area early wood, lumen area late wood, ring width growth response relationship to climate factors in boreal forests. We present growth response from 3-sites KYH (Kheyihe), MEDG (Moredagha), ALH (Alihe) from central Daxing’an mountains China. Variations observed in Cell size from 2010-2016 years in <em>Pinus sylvestris</em> var. <em>mongolica</em> and<em> Larix gmelinii</em>. We analyzed growth response from 2010-2016. Results interoperates that significant growth of <em>Larixgmelinii</em> was lower at ALH-site than <em>Pinus sylvestris</em> var. <em>mongolica </em>as compared to KYH and MEDG-site. We measure the influence of temperature and precipitation which have been shown by correlations of different growing seasons. The warmest temperature from June to September at ALH-site growth of late wood show significant differences at ALH-site. It is also observed that summer temperature in late wood have a significant role in cell dimensions, while the influence of spring temperature frequently influences on tracheid size in early wood formation providing well-documented sound for anatomy and generally used for determining the relationship between maximum growth of tree ring density and effect of temperature variation.展开更多
基金supported by the National Natural Science Foundation of China(31670649,31200484,31170597)
文摘Mongolian pine is an important afforestation species widely used for ecological management in northeast China. The environment in this region is very unstable and the flora are regularly subjected to drought stress.This paper reports on the influence of inoculation with the Suillus luteus on seedlings under different water conditions.Both inoculated and non-inoculated ectomycorrhizal fungi(ECMF)-S. luteus seedlings were maintained under wellwatered or water-stress conditions for 3 months. The S.luteus colonization rate under water stress was higher than that in well-watered conditions. Under water stress, inoculated seedlings had greater growth than non-inoculated seedlings. In addition, under water stress, S. luteus-inoculated seedlings had greater superoxide dismutase and peroxidase activity, higher soluble protein content, lower proline content, and lower malondialdehyde content than non-inoculated seedlings. S. luteus colonization increased the rhizosphere soil-enzyme activity and the rhizosphere soil nutrition content under both well-watered and water-stress conditions. Given the positive impact on seedling growth and physiology, S. luteus shows potential for use in the arid and semi-arid regions of northeast China for afforestation.
文摘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.
文摘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.
文摘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.
基金supported by the Climate Change Special Project of China Meteorological Administration (CCSF201438)the Meteorology Public Welfare Industry Research Special Project (GYHY201106013-3 and GYHY200806011)the Basic Research Operating Expenses of the Central-level Public Welfare Research Institutes (IDM201204)
文摘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.
基金The research was supported by Innovation Research Project of Chinese Academy of Sciences (KZCX3-SW-418), and the 100 Young Researcher Project of Chinese Academy of Sciences.
文摘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.
基金The research was supported by innovation research project of Chinese Academy of Sciences (KZCX3-SW-418), the 100-Young-Researcher-Project of Chinese Academy of Sciences, and by Nature Science Foundation of Liaoning Province (20021006). Acknowledgements We thank Professor Hexin Wang (Dalian University, China), Dr. Professor Zeng Dehui, and the graduate students in research group of Ecology and Management of Secondary Forest (Institute of Applied Ecology, Chinese Academy of Sciences) for their valuable discussion. We are grateful to Mr. Tao Yang (Institute of Applied Ecology, Chinese Academy of Sciences) for his field work. We also thank Dr. Professor Qingcheng Wang (Northeast Forestry University, China), Mr. Menqi Tu and Mr. Yuxiang Ge (Honghuaerji Forestry Bureau, Inner Mongolia, Hulunbeier, China) for providing the convenience during the field investigation.
基金supported by the National Natural Science Foundation of China(31800542,31670649,31200484,31170597)Natural Science Foundation of Liaoning(20180550893)。
文摘This research investigates the mechanism of increased salinity tolerance of ectomycorrhizal fungiinoculated P. sylvestris var. mongolica to provide a theoretical basis for the application of the fungus in saline soils.Growth effects due to inoculation of seedlings with Suillus luteus(a symbiotic ectomycorrhizal fungus), were determined in four kinds of saline–alkali soils. Growth and physiological indicators, including photosynthetic characteristics, plant height, biomass, photosynthetic pigments,catalase(CAT) and superoxide dismutase(SOD) enzyme levels, and malondialdehyde(MDA), an organic marker for oxidative stress, and soluble protein levels were determined. Mycorrhizal colonization rate decreased with increasing saline–alkalinity and growth of inoculated seedlings was significantly enhanced. Biomass and chlorophyll contents also increased significantly. SOD and CAT activities were higher than in non-inoculated seedlings. However, MDA content decreased in inoculatedseedlings. Soluble protein content did not increase significantly. Inoculation with a symbiotic ectomycorrhizal fungus could enhance the saline–alkali tolerance of P. sylvestris var. mongolica. Growth and physiological performance of inoculated seedlings were significantly better than that of uninoculated seedlings. The results indicate that inoculated P. sylvestris var. mongolica seedlings may be useful in the improvement of saline–alkali lands.
文摘This paper summarizes the result from the provenance test of eight years old Pinus sylvestris var. mongolica in Liangshui Natural Rcserve comprehensivcly. The main contents include:(1) the geographic variation of the growth characters of Pinus sylvestris var.mongolica.tends to negative change gradually at latitude and has obvious climatic nature, (2) no significant difference exists in the morphological adaptability and resistant characteristics and so on; (3)on the basis of the geographic variation study on the growth characteristics, the provcnances of Pinus sylvestris var. mongolica were classificd into two geographic populations and two subpopulations as follows:the northern population of the Daxing'an Mountain (Ⅰ) and the southern population of the Daxing'an Mountain as wcll as the Xiaoxinglan Mountain (Ⅱ),which includcs Honghuarii subpopulation and Kalunshan subpopulation (Ⅱ-2). (4) the height growth rhythm was analyzed according to the divided population and subpopuIation; (5) the best provcnance was selected for the Liangshui Natural Rescrve and its neighborhood accord ing to the results from SSR test of the growth characteristics (the breast height diameter and height of eight year old trces), the possibility of the carly provcnance sclection was also verified by the method of order correlation analysis on the height growth of three. five, scvcn and eight years old provenances.
文摘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
文摘The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed.The regressive equation for the estimation of each organ biomass was established through djmensional analysis.Preferable equation with higher precision was selected. The study results showed that the total biomass of theforest community was 62.023 t/hm2 and net primary production was 5.045 V(hm2. a). which indicates that thecommunity of plantation possesses high bio-productivity.
文摘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)。
文摘To find out the Xylem anatomical variations we analyzed the cell structure, lumen area early wood, lumen area late wood, ring width growth response relationship to climate factors in boreal forests. We present growth response from 3-sites KYH (Kheyihe), MEDG (Moredagha), ALH (Alihe) from central Daxing’an mountains China. Variations observed in Cell size from 2010-2016 years in <em>Pinus sylvestris</em> var. <em>mongolica</em> and<em> Larix gmelinii</em>. We analyzed growth response from 2010-2016. Results interoperates that significant growth of <em>Larixgmelinii</em> was lower at ALH-site than <em>Pinus sylvestris</em> var. <em>mongolica </em>as compared to KYH and MEDG-site. We measure the influence of temperature and precipitation which have been shown by correlations of different growing seasons. The warmest temperature from June to September at ALH-site growth of late wood show significant differences at ALH-site. It is also observed that summer temperature in late wood have a significant role in cell dimensions, while the influence of spring temperature frequently influences on tracheid size in early wood formation providing well-documented sound for anatomy and generally used for determining the relationship between maximum growth of tree ring density and effect of temperature variation.