Foliar nutrients in Eucalyptus species in New Zealand.

Foliar nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) concentrations of 5 Symphyomyrtus ( E. botryoides, E. cladocalyx, E. microcorys, E. nitens, E. saligna) and 7 Monocalyptus ( E. agglomerata, E. baxteri, E. globoidea, E. muelleriana, E. obliqua, E. pilularis, E. regnans) species were determined for each of four hill country microsites; upper shady, lower shady, upper sunny and lower sunny slopes. ANOVA and correlation analysis were used to identify species and microsite effects, and nutrient associations. Significant ( P ≤ 0.0014) species differences were identified for all nutrients, E. botryoides and E. saligna generally had high nutrient concentrations while stringybark species were low, particularly for N and K. Subgeneric contrasts revealed that Symphyomyrtus species had significantly higher concentrations of P ( P = 0.05) N, K and Ca ( P < 0.0001) but lower Mg ( P < 0.0001) than Monocalyptus. Microsite had less influence on nutrient concentrations than species. N was strongly positively correlated with P and K in most Symphyomyrtus species but was not correlated with P in Monocalyptus. Mg was positively correlated with Ca but negatively correlated with K in most species. The results indicate that Monocalyptus and Symphyomyrtus species differ in ability to accumulate key macronutrients. [ABSTRACT FROM AUTHOR]