关键词: 非结构性碳水化合物, 氮, 磷, 白桦, 白杄?, 植物器官, 半干旱

Abstract: To examine patterns of nutrient concentrations in different organs, stoichiometry of various nutrients, and the relation of nutrient concentrations with species and the environment, the concentrations of total non-structural carbohydrate (TNC), nitrogen (N), and phosphorus (P) among leaves, stems, tap roots, and first order roots in Asian white birch (Betula platyphylla) and Meyer spruce (Picea meyeri) were studied. The two species were located in the southeastern edge of Inner Mongolia. For TNC, leaves had the highest and first order roots had the lowest concentrations ; the largest difference between them was less than 53%. For N and P, however, there were much higher concentrations in leaves and first order roots than that in stems and the tap roots; the largest difference between them was about 98%. These patterns were determined by the physiological roles (carbohydrate production, nutrient uptake and storage, etc.) that different organs play. In addition, both TNC∶ N and TNC∶ P of Meyer spruce were higher than those of Asian whiter birch, reflecting the physiology of different species and variations in soil nutrient conditions.

Key words: non-structural carbohydrate, nitrogen, phosphorus, Betula platyphylla, Picea meyeri, organs, semi-arid