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林业科学 ›› 2003, Vol. 39 ›› Issue (2): 58-63.doi: 10.11707/j.1001-7488.20030210

• 论文及研究报告 • 上一篇    下一篇

火炬松种子园栽植密度的试验研究

钟伟华 陈炳铨 黄少伟 王金榜 黄永权   

  1. 华南农业大学,广州510642;广东省英德市火炬松种子园,英德513055;广东省林业厅种苗站,广州510173
  • 收稿日期:1999-12-29 修回日期:1900-01-01 出版日期:2003-03-25 发布日期:2003-03-25

RESEARCH ON PLANTING DENSITY IN A LOBLOLLY PINE SEED ORCHARD

Zhong Weihua,Chen Bingquan,Huang Shaowei,Wang Jinbang,Huang Yongquan   

  1. South China Agricultural University Guangzhou 510642;Yingde Loblolly Pine Seed Orchard of Guang dong Province Yingde513055;Seed and Seedling Station of the Forestry Department of Guangdong Province Guangzhou510173
  • Received:1999-12-29 Revised:1900-01-01 Online:2003-03-25 Published:2003-03-25

摘要:

在英德火炬松种子园进行了6m×6m、8m×8m和10m×10m等3种栽植密度试验,13a结果表明,不同栽植密度的高、径、冠幅及产果量差异显著,以8m×8m密度能发挥个体与群体作用,产果量最高,6m×6m次之,10m×10m最差;在郁闭度进入0.6以后,便逐渐抑制产果量上升,需及时疏伐;6m×6m密度因单位面积株数多,早期较高产,适于早期丰产栽培,且因树体较小,便于采果。8m×8m密度适于中长期经营(13a以上) ,如需二者兼取,则可采用4m×8m或4.5m×9m密度,中期疏伐1次,这2种栽植形式利于疏伐与机耕

关键词: 火炬松, 种子园, 栽植密度, 郁闭度, 产果量

Abstract:

The study was carried out within Yingde Loblolly Pine Seed Orchard. Trees were planted in 1986, with three classes of planting density, which was 6 m×6 m,8 m×8 m and 10 m×10 m respectively. Randomized Complete Block Design was used with square plot, three replications. Area and tree number of plot was 0.673 hm2 and 187, 0.665 hm2 and 104, 0.769 hm2 and 77 respectively for the three classes of planting density. Clones involved in different classes of planting density were all the same. All there were 20 clones from 9-year-old superior trees in Pengchang Forest Farm, Hubei Province. Because the tree number within plot was different for planting density, the clones were deployed by their remats with equal rate. Measurement was carried out at 7 and 9-year-old and sampling trees at 13-years-old. Studied traits include height, diameter at breast height(DBH) and crown width. From the 7th to 9th year, cones were collected and weighed by plot in autumn each year.;The results of 13 years showed that there were significant differences between classes of planting density, for the growth in height, DBH and crown width. The density of 8 m×8 m brought the functions of both the individuals and the population into full play, gave the highest cone yield per unit area. It was followed by the density of 6 m×6 m. The density of 10 m×10 m gave the lowest yield. Cone yield per hectare for the three classes of density, at the age of 13, were 470.98, 422.4 and 307.1 kg respectively. The responding mean yield of single tree was 3.93, 1.88 and 4.11 kg respectively. For the density of 6 m×6 m, trees had grown well until the 7th year and then came to close gradually(8~10 a) and competition had become violent. On the other hand, for the density of 10 m×10 m, DBH and crown width had the highest growth. At the age of 13, degree of closing was only 0.57, that was most favorable for fruitage. Competition still didn't happen between trees. Our results also revealed that the degree of closing around 0.6 was most favorable for loblolly pine to fruit, with the highest cone yield per unit area. When the degree up to 0.8, it restrain cone yield obviously. For the planting density of 6 m×6 m, roguing should be implemented at the age of 8~9. For the density of 8 m×8 m, time for roguing come to the 10~11th year. It was concluded that the planting density of 6 m×6 m was suitable for high seed yield in early stage. Meanwhile, the density of 8 m×8 m was suitable for middle to long-term management with high yield. To have both their advantages, the density of 4 m×8 m or 4.5 m×9 m can be used. These two classes of density would give the high cone yield in the early stage,and were convenient for mechanical cultivation.

Key words: Loblolly pine, Seed orchard, Planting density, Degree of closing, Cone yield