Nutrient resorption of two evergreen shrubs in response to longterm fertilization in a bog.
Oecologia
; 174(2): 365-77, 2014 Feb.
Article
em En
| MEDLINE
| ID: mdl-24078082
ABSTRACT
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 calyculata and Rhododendron 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. calyculata resorbed both Ca and Mg while R. groenlandicum resorbed neither. C. calyculata showed a higher resorption than R. groenlandicum, suggesting it is better adapted to nutrient deficiency than R. groenlandicum. Resorption during leaf senescence decreased NP, NK and KP 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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fósforo
/
Potássio
/
Ericaceae
/
Áreas Alagadas
/
Fertilizantes
/
Nitrogênio
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Oecologia
Ano de publicação:
2014
Tipo de documento:
Article