福建柏和杉木人工林营养元素积累与分配

对福建三明33a生福建柏和杉木人工林群落营养元素积累和分配进行了研究,结果表明:福建柏和杉木人工林群落乔木层生物量分别为228.8thm-2和235.1thm-2,N、P、K、Ca和Mg等5种元素总积累量分别为1283kghm-2和1060kghm-2,乔木层和群落5种元素积累量的大小顺序均为:K>N>Ca>Mg>P,5种元素总积累量在乔木层各器官的分配量顺序分别为:干材>枝>根>干皮>叶>枯枝、干材>根>干皮>叶>枝>枯枝。福建柏的营养利用效率低于杉木。虽然两种人工林生态系统94%以上的营养元素储存在土壤中,但是土壤中植物容易利用的有效营养元素储量较低,其中有效P在土壤中的储量低于植物中的储量。福建柏和杉木人工林33 a生时乔木层5种营养元素总和的当年存留量分别为30.75kghm-2和16.53kghm-2。

Nutrient Accumulation and Distribution in Fokienia hodginsii and Cunninghamia lanceolata Plantations

Nutrient accumulation and distribution in 33-year-old Fokienia hodginsii and Cunninghamia lanceolata plantation communities were determined during 1999 to 2000 in Sanming, Fujian, China. The results showed that the biomass in tree layer of F. hodginsii and the C. lanceolata communities were 228.8 t hm-2 and 235.1 t hm-2, respectively, and total accumulation of nutrient elements (N, P, K, Ca, and Mg) being 1 283 kg hm-2 and 1 060 kg hm-2, respectively. The accumulation of nutrient elements in tree layer or in the whole community for both plantations were in the order of K>N>Ca>Mg>P. The total accumulation of the 5 nutrient elements in different parts of trees was in the order of stem wood>branch>root>stem bark>leaf>dead branch for F. hodginsii plantation, and stem wood>root>stem bark>leaf>branch >dead branch for C. lanceolata plantation. The nutrient utilization efficiency of F. hodginsii was lower than that of C. lanceolata. Although over 94% of the nutrient elements in both ecosystems were stored in the soil, available nutrient elements in the soil which could be easily utilized by the plants were rather low, particularly, the reserve of available P in the soil was lower than that in the plants. The amount of annual retention of all the 5 elements in tree layer of the F. hodginsii and the C. lanceolata communities were 30.75 kg hm-2 and 16.53 kg hm-2, respectively.