【摘要】 <正> 东北赤杨(Alnus mandshurica)和毛赤杨(A. sibirica var. hirsuta)广泛分布于我国东北林区,它不仅能适应山地高寒气候和贫瘠土壤条件,而且具有较强的结瘤固氮能力。许多研究表明,赤杨的固氮能力与温度条件关系极大。本研究试图从固氮酶活性与根瘤碳消耗的变化,来探讨两种赤杨在不同温度条件下的固氮效能。更多还原

【Abstract】 Alnus mandshurica and A. sibirica var. hirsuta are tastgrowing species with ability of N₂-fixation widely distpihuted in northeast in China. Assay of N₂-fixing activity and carbon cost by nodule of the two species was conducted in field and laboratory conditions. Techniques of acetylene reduction and infrared gas analyzer were used in the experiments.Results show: 1) Soil temperature was the major environmental factor affecting N₂-fixing activity of alder nodule. 2. The optimum temperature in N₂-fixation was 20℃ for A. mandshurica and 25℃ for A. sibirica var. hirsuta. 3. Ratio of value of N₂ fixed to CO₂ evolved was maximum at 20℃ for A. mandshurica and 25℃ for A. sibirica var. hirsuta. Efficiency of N₂-fixation at temperature bellow 20℃ was higher for A. mandshurica than for A. sibirica var. hirsuta. But it was reverse at the temperature above 25℃.Measures for increasing soil temperature of site are useful in extending the potential ability of N₂-fixation of alder.更多还原