Foliar nutrient allocation patterns in Banksia attenuata and Banksia sessilis differing in growth rate and adaptation to low-phosphorus habitats.
Ann Bot
; 128(4): 419-430, 2021 09 03.
Article
em En
| MEDLINE
| ID: mdl-33534909
ABSTRACT
BACKGROUND AND AIMS:
Phosphorus (P) and nitrogen (N) are essential nutrients that frequently limit primary productivity in terrestrial ecosystems. Efficient use of these nutrients is important for plants growing in nutrient-poor environments. Plants generally reduce foliar P concentration in response to low soil P availability. We aimed to assess ecophysiological mechanisms and adaptive strategies for efficient use of P in Banksia attenuata (Proteaceae), naturally occurring on deep sand, and B. sessilis, occurring on shallow sand over laterite or limestone, by comparing the allocation of P among foliar P fractions.METHODS:
We carried out pot experiments with slow-growing B. attenuata, which resprouts after fire, and faster growing opportunistic B. sessilis, which is killed by fire, on substrates with different P availability using a randomized complete block design. We measured leaf P and N concentrations, photosynthesis, leaf mass per area, relative growth rate and P allocated to major biochemical fractions in B. attenuata and B. sessilis. KEYRESULTS:
The two species had similarly low foliar total P concentrations, but distinct patterns of P allocation to P-containing fractions. The foliar total N concentration of B. sessilis was greater than that of B. attenuata on all substrates. The foliar total P and N concentrations in both species decreased with decreasing P availability. The relative growth rate of both species was positively correlated with concentrations of both foliar nucleic acid P and total N, but there was no correlation with other P fractions. Faster growing B. sessilis allocated more P to nucleic acids than B. attenuata did, but other fractions were similar.CONCLUSIONS:
The nutrient allocation patterns in faster growing opportunistic B. sessilis and slower growing B. attenuata revealed different strategies in response to soil P availability which matched their contrasting growth strategy.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Ecossistema
/
Proteaceae
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article