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作 者 ：叶功富,张立华,林益明*,王亨,周海超,曾琦

期 刊 ：生态学报 2009年 29卷 12期 页码：6519~6526

关键词：短枝木麻黄；氮；磷；养分再吸收率；养分再吸收程度；

Keywords:Casuarina equisetifolia, nitrogen, phosphorus, nutrient resorption efficiency, nutrient resorption proficiency,

摘 要 ：对福建东山赤山林场短枝木麻黄纯林小枝中的N和P含量、N∶P比、养分再吸收率的季节动态进行研究。结果表明，随着小枝的成熟和衰老，各季节N和P的含量依次降低，其中衰老小枝中N和P含量分别为(3.97±0.21)～(8.64±0.58) mg·g-1和(0.04±0.03)～(0.10±0.03) mg·g-1，基本上表现为N和P的完全再吸收。成熟小枝N∶P比的季节动态介于(18.67±324)～(37.98±1.32)之间，均高于16，表明木麻黄的生长受到不同程度的P限制。N、P再吸收率的季节变化分别为(51.02±4.66)%～(63.00±8.61)%和(81.24 ±5.08)%～(91.78±5.84)%，P再吸收率显著高于N。N和P的再吸收率之间以及成熟叶中N、P含量与二者再吸收率之间没有显著相关性，但在衰老叶中存在显著负相关，表明养分再吸收程度越高，其再吸收率就越高。因此，木麻黄通过小枝衰老过程中的养分再吸收，减少养分的损失，从而适应贫瘠的立地条件。

Abstract:Seasonal dynamics of nitrogen and phosphorus concentrations, N∶P ratios and nutrient resorption efficiency of Casuarina equisetifolia branchlets was studied at Chishan Forestry Center of Dongshan County, Fujian Province, China. The results showed that N and P concentrations were highest in young branchlets and decreased with maturity and senescence. N and P concentrations of senescent branchlets ranged from (3.97±0.21) to (8.64±0.58) mg g-1 and (0.04±0.03) to (010±0.03) mg g-1, respectively. N∶P ratios of mature branchlets ((18.67±3.24)~(37.98±1.32)) were all above 16 through the year, showing P was more limiting than N. Nitrogen resorption efficiency (REN) and phosphorus resorption efficiency (REP) were from (51.02±4.66)% to (63.00±8.61)% and from (81.24±5.08)% to (91.78±5.84)% through the year, respectively, and REP was significantly higher than REN. There is no significant correlation between REN and REP. REN is not correlated with either N concentration or N:P ratios in mature branchlets, no correlation was also found between REP and either P concentration or N∶P ratios in mature branchlets. While the significant negative correlation was observed in senescent branchlets.

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