马占相思(Acacia　mangium)的生长、固氮及叶状柄的营养成分

PLANT GROWTH, NODULE NITROGENASE ACTIVITY AND PHYLLODE NUTRIENT CONTENT IN ACACIA MANGIUM

马占相思（Ａｃａｃｉａ ｍａｎｇｉｕｍ）在厦门地区生长良好，生长速度和地上部生物量均大于肯氏相思 （Ａ．ｃｕｎｎｉｎｇｈａｍｉａ）和大叶相思（Ａ．ａｕｒｉｃｕｌａｅｆｏｒｍｉｓ）。４年生的马占相思和大叶相思人工林年凋落物的 干重分别为 １１ ５０ ｇ ｍ~－２和 ６６８ ｇ ｍ~－２。马占相思和肯氏相思根瘤的固氮酶活性均有明显的季节变 化，８月份＞１０月份＞５月份＞２月份。马占相思叶状柄营养丰富，含有较高的蛋白质和氨基酸，特 别是必需氨基酸苏氨酸、缬氨酸、苯丙氨酸、酪氨酸、异亮氨酸等，而且还含有尿囊素。马占相思 不仅可作为纸浆材、胶合板材、建筑和家具用材，以及水土保持林，而且是饲料、食用菌培养基和提 取尿囊素的资源，有广阔的开发利用前景。

Acacia mangium trees planted in 1993 in Xiamen region, Fujian, showed that the growth rate and aboveground biomass were higher than those of A. cunninghamia and A. auriculaeformis. The annual litter-fall of 4-year-old trees of A. mangium and A. auriculaeformis were 1150 g m^-2 and 668 g m^-2, respectively. Seasonal variation of nitrogenase activity in nodules of A. mangium and A. cunninghamia was obvious and was in the order August>October>May>February. The phyllodes of A. mangium were found to contain abundant nutrients, such as protein, amino acids, especially essential amino acid : Thr, Val, Phe, Tyr, Met, Lys, Iie, Leu, and allantoin. The wood of A. mangium is useful materials for building, pulpwood, furniture and plywood, and the phyllodes of which can be used as feed for cattle and as medium for mushroom cultivation. It is also a good species for soil and water conservation.