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用产于加拿大9个种源的扭叶松种子育苗,在湖北恩施的建始县国有高岩子林场的十字坪、姚家坡进行了扭叶松不同种源地、不同种源的植苗造林试验。其幼树期的试验结果表明:扭叶松能适应两地的环境条件,植苗造林成活率及保存率达91.3%~100%;对14年生的试验林进行高、径生长分析,扭叶松的树高生长和胸径生长受种源、造林地点的影响极显著;种源与造林地点对树高生长的交互作用极显著。进一步对树高进行单点分析,参试的9个种源,在十字坪试点,10577、26230、25730、27084、28476、14726、26153七个种源的树高生长极显著高于25801、25803两个种源,且7个种源两两间差异不显著;姚家坡试点10577种源的树高生长极显著高于其他种源,其下依次是28476、26153、26730、27084、14726五个种源。胸径生长在种源间的极显著差异缘于10577种源与25803、25801种源间的差异,其他任意两种源间的胸径生长差异不显著。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):233-242
Scots pine and different provenances of lodgepole pine were compared in regard to root characteristics and the distribution of biomass within individual trees. Tap root formation was more frequent and the root/shoot ratio was higher on Scots pine than on lodgepole pine but significant variation of these traits was found between provenances of planted lodgepole pine. A non‐destructive method for estimation of root biomass was developed. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):113-121
Scots pine (Pinus sylvestris) and lodgepole pine (Pinus contorta) needle litters were compared in terms of nutrient composition and its change during decomposition. Initial nutrient composition differed between the species, with lodgepole pine needle litter having significantly higher concentrations of P, Mg and Mn. However, no difference was found for concentrations of N, Ca or K. Increases in concentrations of N, P and K during decomposition were significant in both litter types. For Ca the pattern of concentration changes followed a quadratic function as decomposition proceeded. Concentrations of Mg and Mn decreased in lodgepole pine needle litter. In Scots pine litter there was also an initial decrease, but it was followed by an increase in most incubations. For both Mg and Mn, changes in concentrations during decomposition differed significantly between species. In the late decomposition stages, concentrations of Mg and Mn became similar in both litter types. Nutrient concentrations generated by the models were compared with those of the humus (F and H) layer in the stands. The model was quite accurate in predicting concentrations of N and P for both species and the concentration of Mg for lodgepole pine. By contrast, it was not accurate in predicting concentrations of Ca and Mn. Nutrient release was estimated for the two species using both measured litterfall data and long‐term estimates, and regression models were used to predict concentration changes. Rates of release of P, Mg and Mn in the lodgepole pine stands were found to be about twice as high compared with those in Scots pine. Calcium was also released to a greater extent although the difference was not significant. 相似文献
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北马兜铃不同部位乙醇浸提液对玉米蚜生物活性研究 总被引：1，自引：0，他引：1
利用均匀设计法研究了北马兜铃根、茎和叶乙醇浸提液对玉米蚜的生物活性。结果表明:北马兜铃根的乙醇浸提液对玉米蚜具有明显的触杀作用,24 h和48 h的致死中浓度(LC50)分别为18.06、16.67 mg/L,48 h的致死率达98.3%。叶的乙醇浸提液对玉米蚜具有明显的拒食作用,24 h和48 h的拒食中浓度(AFC50)分别为18.62、18.22 mg/L,48 h的拒食率达98.2%。茎的乙醇浸提液触杀和拒食作用均不明显。 相似文献
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PENG Limin FU Feng LU Keyang Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(2):20-24
In the article, with the instruments of the Research Institute of Wood Industry, Chinese Academy of Forestry, the experiment method of Forintek Canada Corp. was used to test the laminating of lodgepole pine containing beetle-transmitted bluestain; finally the result was compared with Canada report. The results show that the presence of glue joints of bluestained wood made with either PVA or PRF adhesive makes no difference to the shear strength of the joints, and no difference to durability of the joints using PRF. Also the presence of beetle-transmitted bluestain in wood does not affect the adherence of the interior finishes tested. 相似文献
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Research conducted on shoot dieback of lodgepole pine, Pinus contorta, during the early 1980's in west Scotland is summarised. The dieback symptoms and their stages of development are described. Ramichloridium pini de Hoog and Rahman was regularly isolated from bark and xylem tissue of dieased shoots. Artificial inoculations established that this fungus was the cause of the disease. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):137-146
Seeds of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) collected southwest of Grande Praire, Alberta at three different times and altitudes between August 20, 1984 and August 15, 1985 showed variable responses to stratification. The responses were related to seed ripeness, as judged through evaluations of cone moisture contents, and with the length of time that the cones had remained on the trees. Unripe seeds started to lose germination in the third year after pollination when on the tree. Mature seeds which lost germination by late fall 1984 regained it by the next fall, while most unripe seeds did not. Immature seeds increased their need for stratification over time while mature seeds did not. Seeds should be left on the tree until the end of the third year to insure maximum viability because they do not reach maturity until then. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):201-212
A field experiment was established in two Picea abies (L.) Karst. plantations in southern Sweden to study yield and effects of competition on growth in beeted stands. Beeting was carried out in gaps where originally planted seedlings had been removed. Tree species used for beeting were P. abies, Pinus sylvestris L., Pinus contorta Dougl. and Larix decidua Mill × L. leptolepis Gord. The plantations were beeted when mean heights were 95 cm (Ullasjo) and 40 cm (Knäred). Effects of competition on diameter growth of P. abies were found when originally planted stands were 2.5 and 3.5 m in height. On both sites, diameter growth in stump height was significantly lower for seedlings beeted in small gaps (approx. 20 m2) than for seedlings beeted in the middle of large gaps (approx. 155 m2). This difference was larger at Ullasjo than at Knared. About 50 % of the P. sylvestris 70 % of the P. contorta and 80% of the L. decidua x L. leptolepis were dead or severely damaged six years after beeting. The main causes of damage were fraying and browsing by moose and roe‐deer. 相似文献