西南桦的栽培技术

在对西南桦的生物学特性、生长、用途以及分布区较详细论述的基础上,主要对西南桦的栽培技术进行了研究。结果表明,发展西南桦人工林的关键在于选用适生种源,适时采种,正确处理和保存种子,种子必须低温 (10℃以下)保存。造林最好用营养苗,7～8月播种,10月中～11月中将芽苗移入营养袋内继续培育,3～4月出圃造林。育苗基质要疏松,排水性能要好,苗期要加强水肥管理,苗高 2 0～30 cm时出圃造林。在上年的 11～12月整地,采用带状或穴状整地方式,穴要大(5 0 cm× 5 0 cm× 4 0 cm)。造林要适时,一般 3～4月,在干湿季明显的地区,7～8月雨季定植,造林密度 2 m× 3m或 3m× 3m。造林前施基肥,造林后要加强抚育管理和追肥,连续进行 3a。对造林密度为 2 m× 3m的林分,植后 6～8a要进行第 1次间伐。

Cultivation Techniques of Betula alnoides

The paper introduces Betula alnoides Hamilt. in terms of its speciality of growth, utilization, distribution zones, and cultivation technlques. The species is widely distributed in tropical and subtropical area of Vietnam, Laos, Burma, Thailand, India as well as Yunnan, Hainan and southern Guangxi of China with characters of fast growth, enduring infertile soil condition. It is a suitable tree species for restoring degraded lands,reclaiming degraded forests.Specially,the wood of the species with good property is of high market value and usually used to make evneer and furniture. Over logging had led to depletion of natural resources of the species. The urgent thing to do is to develop its plantation for meeting the increasing demand of people and society. The key of developing the plantation lies in duly collection, conservation and,treatment of seeds. The potted seedlings are needed. The schedule is to seminate seeds in July or August, pot in October, and plant in March or April of next year when the seedlings reacn the height of 20～30 cm? In nursery,watering and fertilizer application should be attended. Generally, planting season is from March to April, but it is possible from July to August for districts with clear dry and wet season. There are two manners of site preparation, one is to make strip line, the other is to dig holes (50 cm×50 cm×40 cm). Planting is followed by application of base fertilizer with spacing of 2 m×3 m or 3 m×3 m. Tending is needed in the coming three years after planting, and the first thinning is suggested in 6 to 8 years.