落叶松水曲柳、落叶松胡桃楸混交林的调查研究

STUDY ON BOTH LARIX GMELINI X FRAXINUS MANDSHURICA AND LARIX GMELINI X JUGLANS MANDSHURICA MIXED STAND

落叶松(Larix gmelini)—水曲柳(Fraxinus mandshurica)和落叶松—胡桃楸(Juglans mandshurica)混交林的直径、树高、材积(单)生长量和单位面积蓄积量等平均测树指标,都明显高于相应树种的纯林,即:直径高9％—54％,树高10％—30％,材积(单)24％—75％,公顷蓄积量20％—36％,混交林中各树种的树干形质指标,特别是枝下高和形率都比相应树种的纯林高;混交林下的土壤A层有机质,水解氮、速磷含量及A_2层的pH值,分别比各树种纯林高14％—98％,7％—48％,29％—104％及1个单位;同时混交林在防止落叶松早落病和松毛虫以及胡桃楸根腐方面的危害,具有显著的生物防治效果,从而使混交林比纯林更稳定,更能达到速生、丰产、稳产的造林目标,值得林业生产部门重视。

Diameter, height, volume increment, and stand volume on a unit area are obviously higher in both Larix gmelini and Fraxinus mandshurica mixed stand and Larix gmelini and Juglans mandshurica mixed stand than that in pure stands of these tree species as well as under branch height and form quotient, that is, diameter increased by 9％—54％, tree height by 10％—30％, volume by 24％—175％ and stand volume per hectare by 20％—96％. Soil organic matter at A-Layer, available N and P, and pH at soil A_2-Layer are higher 14％—98％, 7％—48％, 29％—104％ and one unit respectively in the two mixed stands than that in the pure stands. Besides above, the mixed stands have obviously biological control effect in preventing mycospahaerella larici-leptolepis, dendrolimus superans butler and root rotting of Juglans mandshurica, therefore, they are more stable than pure stands and can meet for the needs of fast growth, high and stable yield in forest production.