Characteristics of Seven Nutrient Elements in Needles of Pinus massoniana and Cunninghamia lanceolata Forests in Fujian Province

Abstract:

In order to understand the characteristics of nutrient requirement in Pinus massoniana and Cunninghamia lanceolata forests in Fujian, China, the concentrations of seven nutrient elements, including C, N, P, S, K, Ca, and Mg, in needles collected from 25 P. massoniana plots and 31 C. lanceolata plots were determined. The results showed that the concentrations of needle K, Ca and Mg in P. massoniana were only 68%, 14% and 50% of those in C. lanceolata, respectively, indicating the demand for mineral elements, particular Ca, were markedly higher by C. lanceolata than by P. massoniana, with an important implication that P. massoniana has much higher potential adaptability to poor nutrients, particular Ca impoverished sites than C. lanceolata. Both tree species showed similar homeostasis either in concentrations of C, N, P and S or in their stoichiometric ratios. In contrast, large variabilities of Ca, Mg and K concentrations and their stoichiometric ratios were observed in both species, revealing the large influence of site condition on these elements. Both species showed positive synergy relationships for the demands of N, P and K, while negative correlations were observed between N and Ca. This suggests that atmospheric N deposition or long-term application of N fertilizers through forest management may cause the inhibition of Ca uptake.

Key words:Pinus massoniana;Cunninghamia lanceolata;Needle;Nutrient element;Stoichiometric ratio