贫瘠丘陵地短轮伐期薪材树种生长过程的研究

尾叶桉、细叶桉、赤桉、粗皮桉、巨桉（简称桉树类，下同）和马占相思、粗果相思及薄果相思（简称相思类，下同）等８个树种，在水土严重流失的贫瘠丘陵地经７年的生长试验，结果表明：除巨桉和细叶桉在该立地生长较缓慢外，其余６个树种生长快，产量较高。尤其是尾叶桉和马占相思，７年生胸径年均生长量在１．０ｃｍ以上，单位面积生物量（地上部分鲜重，下同）为５２．６９ｔ／ｈｍ２和４３．６７ｔ／ｈｍ２。不同树种的生长比较：桉树类树种（除巨桉外）４年生以前胸径、树高和生物量生长均比相思类树种生长快，４年后相思类树种逐渐赶上或超过桉树类树种。性状生长高峰期分别为：胸径桉树类为２年生（细叶桉１年生）、相思类为３～４年生，树高桉树和相思类均为１年生，生物量桉树类为２～３年生、相思类为４～６年生。

RESEARCH ON THE GROWTH PROCESS OF SHORT ROTATION\= FUELWOOD SPECIES IN INFERTILE HILLS

The growth of 5 eucalypt species and 3 acacia species planted in the heavily eroded and infertile hills have been measured for 7 years. The results showed that Eucalyptus grandis and E. tereticonis grew slower than the other species. Acacia mangium and E. urophylla, grew well with annual DBH growth rate 1.0 cm at age of seven. The biomass of the two species reached 52.69 t/hm2 and 43.67 t/hm2 respectively. The growth speed of eucalypt species (except E. grandis) in terms of DBH, height and biomass is faster than acacia species during the previous 4 years after planted. 4 years later, the growth of acacia species surpassed eucalypts. The peak of DBH growth of eucalypts appeared at the first or the second year after planted, but at the third or the forth for acacia. For the two species, the peak of height growth was all at the first year. The biomass peak of eucalypts and acacia is at 23 and 46 years old respectively.