滨海沙地主要造林树种的热值和营养元素及其相关性

对滨海沙地3种造林树种的热值、灰分质量分数和营养元素质量分数及三者之间的相关关系进行了研究。结果表明：3种造林树种的平均干质量热值和平均去灰分热值，湿地松Pinuselliottii（20．96kJ·g-1，21．41kJ·g-1）与厚荚相思Acaciacrassicarpa（20．97kJ·g-1，21．35kJ·g-1）接近，但均高于木麻黄Casuarinaequisetifolia（20．18kJ·g-1，20．69kJ·g-1）。具体数值因树种和器官不同而异。植物碳质量分数在器官间分布没有规律性，总体上，湿地松的平均碳质量分数（491．548g·kg-1）高于厚荚相思（471．773g,kg-1）和木麻黄（460．042g·kg-1）。氮、磷、钾、钙和镁等在3树种不同器官中的分布规律为叶最高，枝、皮和根次之，干最低。干质量热值与镁质量分数呈显著正相关关系（P〈O．05），与氮、磷、钾质量分数呈极显著正相关关系（P〈O．01）。灰分质量分数与磷质量分数呈极显著正相关（P〈O．01），与钾、钙、镁等质量分数显著正相关（P〈O．05）。氮、磷、钾、镁等质量分数两两之间均呈极显著正相关关系（P〈O．05）。袁4参】5

Caloric values and correlations of nutrient elements in three forestation species of a coastal sandy land

The objective is to examine and compare the allocation patterns of caloric and elemental contents for three forestation species on coastal sandy land, and to summarize correlations between caloric values and elememtal contents. In July of 2010, three forestation species （Pinus eUiottii, Acacia crassicarpa and Casuar- ina equisetifolia） were sampled from a coastal sandy land in Dongshan County, Fujian Province. All organs of each tree species were harvested. The gross caloric values （GCV） were measured by oxygen bomb calorimeter. Ash, and the contents of C, N, P, K, Ca and Mg were analyzed. The results showed that the mean gross caloric values and the mean ash free caloric values decreased in the following order： P. elliottii （20.96 kJ·g-l, 21.41 kJ·g-1） ≈A. crassicarpa （20.97 kJ·g-1, 21.35 kJ·g-1）〉C, equisetifolia （20.18 kJ·g-1, 20.69 kJ·g-1）. The mean C content in P. elliottii （491.548 g·kg-1） was higher than in A. crassicarpa （471.773 g·kg-1） and C. equisetifolia （460.042 g·kg-1）. The N, P, K, Ca, and Mg content in different organs of these three species were as follows： leaves〉branches〉barks〉roots〉stems. The mean content of N, P, K, Ca, and Mg of A. crassicarpa were the highest, then was C. equisetifolia, P. elliottii was the lowest. Gross caloric value was significantly correlated with Mg content （r =0.600, P 〈 0.05） and with content of N （r = 0.641, P 〈 0.01）, P （r = 0.879, P 〈 0.01）, and K （r = 0.726, P 〈 0.01）. Ash content was significantly correlated with P con- tent （r = 0.673, P 〈 0.01） and was significantly correlated with content of K （r = 01524, P 〈 0.05）, Ca （r =