黄河口滨岸潮滩不同生境下翅碱蓬生物量空间分形特征与磷营养动态

2008年5-11月,对黄河口滨岸潮滩不同生境下翅碱蓬的生物量空间分形特征及磷(P)营养动态进行了研究。结果表明,中潮滩翅碱蓬(JP1)和低潮滩翅碱蓬(JP2)地上生物量与株高的对数值线性相关(P＜0.01),分形维数(D)分别为1.692～3.839 和2.260～3.955,二者地上生物量的动态积累具有自相似性,分别遵从D=2.012和D=2.366幂函数增长的分形生长过程;JP1、JP2根、茎的全磷(TP)含量变化较为一致,整体呈递减趋势,而叶的TP含量波动变化明显且差异较大。二者不同器官的P累积量和累积速率季节变化明显,前者不同器官的P累积量一般明显高于后者;JP1、JP2不同器官的P分配比在各时期差异较大,但整体以叶的分配比占优,茎次之,根最低;JP1、JP2不同器官N/P变化具有明显的时间性,前者为9.87±3.47＜14,其生长受N限制,而后者为15.73±5.00＜16,其生长同时受N、P限制,但更多受P限制。研究发现,JP1、JP2生物量、TP含量、累积量、累积速率、分配比和养分限制状况的差异主要与其生态学特性和所处生境的水盐状况有关。

Biomass spatial fractal characteristics and phosphorus nutrient dynamics of Suaeda salsa under different growth conditions of the intertidal zone in the Yellow River estuary

From May to November 2008, biomass spatial fractal characteristics and phosphorus nutrient dynamics of Suaeda salsa under different growth conditions in the intertidal zone of the Yellow River estuary were studied. The logarithm values of aboveground biomass and plant height of S. salsa in middle (JP1) and low tidal flat (JP2) were linearly correlated, and the ranges of fractal dimensions (D) were 1.692-3.839 and 2.260-3.955, respectively. The dynamic accumulation of aboveground biomass of JP1 and JP2 had self-similarity, being a fractal growth process which fitted the increase rule of power function: D was 2.012 and 2.366, respectively. The changes of total phosphorus (TP) content in roots and stems of JP1 and JP2 were consistent, generally decreasing in the growing season, while TP content in leaves fluctuated greatly. The amount of P accumulation and rate of different organs of JP1 and JP2 showed significant seasonal changes, and the values in aboveground parts were generally higher than those in roots. The P allocation ratios were significantly different among different parts of JP1 and JP2 in different phases and were in the order leaf＞stem＞root, with values of (45.38±20.08)%, (38.88±20.30)%, (15.74±8.94)% for JP1 and (57.08±15.49)%, (35.30±13.12)%, (7.63±5.25)% for JP2 respectively. The N/P of JP1 plants (9.87±3.47) was less than 14, implying that N might be the limiting nutrient. The N/P of JP2 plants (15.73±5.00) was between 14 and 16 indicating that both might be limiting nutrients, but that the effect of P is greater. Further studies indicated that the differences between JP1 and JP2 in biomass, TP content, P accumulation amount and rate, P allocation ratio and nutrient limiting status were correlated to their ecological characteristics and water and salinity conditions of the habitat.