Nutrient resorption of two evergreen shrubs in response to long-term fertilization in a bog
Nutrient resorption of two evergreen shrubs in response to long-term fertilization in a bog
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DOI：
10.1007/s00442-013-2784-7
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发表时间：
2014-02
期刊：
影响因子：
2.7
通讯作者：
M. Wang;Meaghan T. Murphy;T. Moore
中科院分区：
文献类型：
--
作者：
M. Wang;Meaghan T. Murphy;T. Moore
植物在叶子衰老过程中对多种养分的吸收已经确定，但对吸收过程中和受精后氮、磷和钾之间的化学计量变化知之甚少。我们预计，氮供应的增加将导致磷的进一步限制或与氮或钾的共同限制[即。 P-（共）限制]，减少N重吸收并增加P和K重吸收，而添加P和K会减少P和K重吸收并增加N重吸收。此外，无论是否施肥，在叶子衰老过程中，Ca 都会积累，而 Mg 会被吸收。我们在加拿大安大略省 Mer Bleue 沼泽进行长期施肥实验，研究了氮、磷和钾的添加对两种常绿灌木（Chamaedaphne calyculata 和 Rhododendron groenlandicum）吸收的影响。一般来说，氮的添加导致进一步的磷（共）限制，增加磷和钾的再吸收效率，但不影响氮的再吸收。 P和K的添加并没有使系统转向N限制并影响K吸收，但降低了P吸收效率。C．花萼吸收Ca和Mg，而R。绿地仙人掌均不被吸收。 Calyculata表现出比R更高的吸收。 groenlandicum，表明它比 R 更好地适应营养缺乏。格伦兰迪库姆。叶片衰老过程中的吸收降低了 N:P、N:K 和 K:P 比率。氮和钾的有限反应以及磷吸收对施肥的反应反映了养分循环的化学计量耦合，这在两种灌木物种之间有所不同；物种组成的变化可能会影响沼泽的养分循环。
Plant resorption of multiple nutrients during leaf senescence has been established but stoichiometric changes among N, P and K during resorption and after fertilization are poorly understood. We anticipated that increased N supply would lead to further P limitation or co-limitation with N or K [i.e. P-(co)limitation], decrease N resorption and increase P and K resorption, while P and K addition would decrease P and K resorption and increase N resorption. Furthermore, Ca would accumulate while Mg would be resorbed during leaf senescence, irrespective of fertilization. We investigated the effect of N, P and K addition on resorption in two evergreen shrubs (Chamaedaphne calyculataandRhododendron groenlandicum) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada. In general, N addition caused further P-(co)limitation, increased P and K resorption efficiency but did not affect N resorption. P and K addition did not shift the system to N limitation and affect K resorption, but reduced P resorption proficiency.C. calyculataresorbed both Ca and Mg whileR. groenlandicumresorbed neither.C. calyculatashowed a higher resorption thanR. groenlandicum, suggesting it is better adapted to nutrient deficiency thanR. groenlandicum. Resorption during leaf senescence decreased N:P, N:K and K:P ratios. The limited response of N and K and the response of P resorption to fertilization reflect the stoichiometric coupling of nutrient cycling, which varies among the two shrub species; changes in species composition may affect nutrient cycling in bogs.