Relationships between nutrient status, carbon assimilation and water use efficiency in Pinus radiata (D. Don) needles

Abstract

The productivity of Pinus radiata D. Don plantations can be increased on many soils by N and P fertilization. Foliar analyses are usually taken as a guide for nutrient management, but there is little information about the relationship of foliar nutrient status to foliar physiology. This paper provides such information from N and P fertilization experiments. The concentrations and contents of N and P in the needles of P. radiata change because of accumulation during needle growth, retranslocation during shoot growth, and replenishment from current uptake during periods of little shoot growth. Up to 60% P and 50% N may be retranslocated in a single growing season from needles less than one year old. Three years after fertilizer application to a 10-year-old thinned P. radiata stand, net carbon assimilation rate per unit leaf area was in the order NP>P>N. There were positive associations between foliar P and assimilation at full sunlight, diffusive conductance and quantum yield. Foliar N was negatively associated with these variables. Higher concentrations of P and N were both accompanied by higher instantaneous water use efficiency by the foliage. Estimated trends in whole tree assimilation were similar to those in aboveground biomass accumulation. The interplay between the dynamic nature of nutrients in the foliage and their influence on the physiology of needles is discussed.

Effects of phosphate deficiency on photosynthesis and accumulation of starch and soluble sugars in 1-year-old seedlings of maritime pine (Pinus pinaster Ait)

“…However, little is known about the effects of phosphorus deficiency on carbon assimilation in forest tree species (Ericsson and Ingestad, 1988). In Australia, P fertilization of Pinus radiata increased stand biomass and the maximal rate of photosynthesis (Sheriff et al, 1986). The same results were observed in Eucalyptus grandis seedlings (Kirschbaum et al, 1992).…”

Interactive effects of phosphorus and light availability on early growth of maritime pine seedlings

“…Increased growth in response to enhanced P availability was commonly reported for many tree species either in the field or under artificial growth conditions [9,52,55,57]. Chang [9] showed that increasing P supply from 0 to 50 kg P ha -1 increased basal diameter and height increment of two-month-old sweetgum seedlings by 24 and 22%, respectively.…”

“…Studies on interactions between light and phosphorus are still scarce, although phosphorus is a common limiting factor for tree growth in natural environments [52,57]. Increased growth in response to enhanced P availability was commonly reported for many tree species either in the field or under artificial growth conditions [9,52,55,57].…”

Differential response of leaf conductance, carbon isotope discrimination and water‐use efficiency to nitrogen deficiency in maritime pine and pedunculate oak plants

“…However, studies on the effects of nutrient status on water-use efficiency, i.e, the quotient of biomass production to water use, remain scarce in tree species and practically all refer to leaf instantaneous wateruse efficiency (ratio CO^ assimilation rate/ transpiration rate, A/E). In most species, this ratio decreased when P (Sheriff, Nambiar & Fife, 1986;Guehl & Garbaye, 1990) or N (Sheriff et al, 1986;Reich, Walters & Tabone 1992) availability was authors (Stark, 1992 have found that A/E N concentration in Eucalyptus trees. The uniqueness among fo of water-use efficienc…”