| Daxing’an Mountains Range as Chinese important timber production base, is currently faced with the problem of reduction of the total forest resources, ecological function degradation, while Tending Felling can cultivate forest, and get the wood. Therefore, explore the growth situation of timber and seedling in Daxing’an Mountains for different tending intensity, contribute to sustainable management. In this study,we set up different intensity tending of larch timber forest in Daxing’an Mountains Mountains (cutting intensity: 0.00%～67.3%), and planting mongolica, larch and Korean pine for transformation, and measure timber growth, canopy and photosynthetic by using laser range finder, canopy analyzer and photosynthetic apparatus. The results showed that:Different intensity of tending to the timber in Daxing’an Mountains has different effects on the growth, the high growth of larch timber has no apparent change indifferent intensity tending; With the increase of tending intensity, the DBH growth and individual volume of larch forest rising. Seedling survival rate and ground diameter, high growth rates are higher than to the same (except tending intensity for 67.25% of the Korean pine seedling and tending intensity of 3.42% and 6.23% larch seedlings), three kinds of seedling growth rate overall performance for the longitudinal is greater than the radial; Korean pine and larch seedlings survival rate, diameter growth rate, high growth rate and mongolica seedling ground diameter, high growth rate of the increase of the intensity of tending first increases then decreases.The natural timber forest canopy structure parameters of Larix gmelini are Gap Fraction, Openness, LAI, Total Site Factor, PPFD Total Under Canopy, there have a significant positive correlation (P<0.01) between the any two parameters, and they all have a significant negative correlation with the LAI (P<0.01),but have no apparent correlation with the Mean Leaf Angle; The mean of canopy structural parameters are as follows, Gap Fraction 5.511%,Openness 6.417%,LAI 5.799,Mean Leaf Angle 15.175°,Total Site Factor 0.109, PPFD Total Under canopy 1.38 mol·m-2·d-1,The mean sunlight flux intercepted by canopy 20.73 mol·m-2·d-1.With the cutting intensity increased, the Gap Fraction,Openness, Total Site Factor, PPFD Total Under Per Day decreases and then increases, the LAI increases and then decreases, the cutting intensity had no obvious effect on the Mean Leaf Angle; the light condition of Larix gmelini Seedlings improved obviously in each cutting samples, the photosynthetic index such as net photosynthetic mre(Pn), transpiration rate (E), stomatal conductance(Gs), concentration of environmental CO2 (Cref), concentration of Intercellular CO2(Cz), light intensity of Leaf surface (Qleaf), leaf temperature (Tleaf) also higher than that in the control sample; The diurnal variation of net photosynthesis rate presents a curve with one peak, and the relationship between light intensity and net photosynthetic rate present a equation of one basic repeated, as heat increases, the net photosynthetic rate increases first and then decreases.In the sample with tending intensity between 20.86% and 40.01%, the growth rate of trees, forest stand volume has increased significantly, the seedling survival rate and diameter, high growth rate is highest, timber forest canopy indices and larch seedlings photosynthetic parameters optimal performance, raise the best effect. |
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