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氮、磷在植物的生长和代谢过程中具有关键作用,是陆地生态系统生产力的主要限制因素。植物克服氮、磷元素对生长限制的一个重要策略就是从凋落前的凋落叶中进行养分再吸收。选取武夷山国家自然保护区不同海拔黄山松的成熟叶与凋落叶,测定其C、N、P含量,分析N/P及N、P养分再吸收效率随海拔梯度的变化特征。结果显示:(1)黄山松成熟叶全氮、全磷含量变化范围分别是14.94~21.45 mg·g~(-1)与0.86~1.51 mg·g~(-1),凋落叶全氮、全磷含量变化范围分别是4.73~7.17 mg·g~(-1)与0.16~0.30 mg·g~(-1);(2)成熟叶片N/P随海拔升高而显著降低,凋落叶片N/P则随海拔升高呈指数递增趋势;(3)成熟叶N/P与土壤N/P显著正相关,而凋落叶N/P则随土壤N/P的升高指数降低;(4)叶片N、P再吸收效率随海拔升高呈先降低后升高的趋势,且各海拔叶片P再吸收效率显著大于N再吸收效率。表明黄山松具有较高的N、P元素的再吸收效率,而且相对于N、P元素是该区域黄山松养分循环的关键因素。
Nitrogen and phosphorus play key roles in the growth and metabolism of plants and are the major limiting factor in terrestrial ecosystem productivity. Plant to overcome the nitrogen and phosphorus elements of growth constraints is an important strategy from the litter before litter for nutrient reabsorption. The mature leaves and litter leaves of Pinus taiwanensis at different elevations in Wuyishan National Nature Reserve were selected to determine the content of C, N and P, and the change characteristics of N / P and N, P nutrient reabsorption efficiency with altitude gradient were analyzed. The results showed that: (1) The contents of total nitrogen and total phosphorus in mature leaves of Pinus taiwanensis varied from 14.94 to 21.45 mg · g -1 and from 0.86 to 1.51 mg · g -1, respectively, P content ranged from 4.73 to 7.17 mg · g -1 and from 0.16 to 0.30 mg · g -1, respectively. (2) The N / P of mature leaves decreased significantly with the altitude increasing, and the N / (3) Mature leaf N / P was positively correlated with soil N / P, while litter leaf N / P decreased with soil N / P increasing index; (4) Leaf N, P reabsorption efficiency decreased first and then increased with elevation, and the P resorption efficiency at each altitude was significantly higher than N reabsorption efficiency. It showed that P. dahurica had higher N and P reabsorption efficiency, and P and P were the key factors of the nutrient cycle of Pinus taiwanensis in this region.