改进马尾松育苗方法的试验

对马尾松采用控制苗木密度、芽苗截根移栽和接种菌根菌等技术进行育苗试验，结果表明：苗木密度应控制在１５０株／ｍ２，芽苗截根以保留主根长度１／２为宜；采用厚环乳牛肝菌进行人工接种效果较好。     

Woody and herbaceous competition effects on the growth of naturally regenerated loblolly and shortleaf pines through 11 years

Four levels of vegetative competition were used to quantify the growth of loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) in naturally regenerated, even-aged stands on the Upper Coastal Plain of southeastern Arkansas, USA. Treatments included: (1) no competition control, (2) woody competition control, (3) herbaceous competition control, and (4) total control of nonpine vegetation. After pines became established from natural seeding, herbicides were used to control herbaceous plants for 4 consecutive years and woody plants for 5 consecutive years. Even though 89% of crop pines on untreated check plots were free-to-grow 11 years after establishment, crop pines on vegetation control plots were larger (P<0.001) in mean dbh, total height, and volume per tree. From age 5 through 11 years, crop pine diameter growth increased on woody control plots and decreased on herbaceous control plots because of hardwood competition in the latter treatment. At age 11, crop pine volume production averaged 207 m³/ha on total control plots, 158 m³/ha on herbaceous control plots, 130 m³/ha on woody control plots, and 102 m³/ha on untreated check plots.     

Seasonal changes of understorey herbage yield in relation to light intensity and soil moisture content in a Pinus pinaster plantation

The relationship of understorey herbage yield with light intensity and soil moisture content was investigated in a 20-year-old Pinus pinaster plantation in Kilkis of Macedonia, northern Greece, in three seasons (fall, winter and spring). The plantation was thinned at three density levels, high, medium and low (2500, 1750 and 1000 trees/ha respectively) and it was seeded with Dactylis glomerata. In addition, two fertilization levels (0 and 110 N+150 P₂O₅ kg/ha) and grazing intensity levels (0 and 0.8 sheep/ha/yr) were applied in a split-split plot experimental design. It was found that herbage yield was highest in the ungrazed and fertilized low tree density stands in all seasons. In the medium tree density stand, although light was lacking, fertilized plots produced higher herbage yield as compared to unfertilized low tree density stands while fertilization is of no use in close stands if herbage production is the goal. Animals seemed to prefer fertilized and medium density stands. Third degree polynomial equations were the best to explain herbage variation through the seasons both in fertilized and unfertilized plots.     

Selection, propagation and cultivation of Pinus massoniana clones for pulp use

Based on the growth, wood property of the ortets, and rooting abilities of cuttings, 32 Pinus massoniana clones for pulp use were selected from forests of superior provenance, mixed families, and progeny test of seed orchard by two-step selection. The average height and DBH growth of three-year-old clones were 28.6% and 16.7%, respectively, higher than those from seedlings, and average gain of wood density reached 8.7%. Rooting rate of all these clones was over 80%, 28% higher than the clones selected by a single step. A cutting orchard of 0.33 hm² on the hillside was constructed to intensively produce cuttings according to the tests on construction methods, pruning, and fertilization. A total of 50,000 grade I, 37,500 grade II, and 62,500 grade III cuttings were collected per hectare of this cutting orchard each time, and were cut three times each year. With all the above techniques, 48 hm² of clonal forests for pulp use of those clones had been planted in five places in Fujian Province. Container stecklings are more likely to increase the planting survival rate. __________ Translated from Scientia Silvae Sinicae, 2004, 40(1): 64–69 [译自: 林业科学]     

马尾松林冠下套种阔叶树种林分的生长效应

在30年生马尾松林下进行了不同阔叶树种套种试验.结果表明:在马尾松林冠下套种不同阔叶树种生长存在明显差异,其蓄积大小排序为拉氏栲>格氏栲>青栲>苦槠,其中20年生拉氏栲的年平均蓄积生长量分别是格氏栲、青栲和苦槠的1.06、1.26和1.49倍;拉氏栲和格氏栲是马尾松林冠下套种的首选树种,生长中等的树种有青栲,苦槠生长较差,不适宜作为马尾松林冠下造林树种;利用马尾松林分具有林冠稀疏和透光度大的特点,在马尾松林冠下套种拉氏栲、格氏栲不仅能充分利用林分地上和地下的空间,而且对于减轻马尾松林松毛虫危害具有重要现实意义,是值得南方林区大力推广的林冠下套种模式.     

Growth and nutritional responses of bareroot Jeffrey pine on a Sierra Nevada surface mine to minisite applications of fertilizer and lime

The effects of two controlled release fertilizers, Forestcote 22-4-6 + Minors and Dry Site 21-6-2 + Minors, and also dolomitic lime, on growth and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were investigated. Forestcote, which consists of loose prills, and Dry Site, consisting of prepackaged prills, were administered with two rates, while a single liming rate was used. An acidic Sierra Nevada surface mine provided the study site, and all amendments were applied at outplanting to the backfill of augered planting holes. Without impacting survival, both fertilizer formulations enhanced seedling growth, particularly at a 16 g rather than an 8 g application rate, although Forestcote was marginally more effective in this regard. In contrast, liming at a 27 g rate induced severe mortality and offset much of the growth gains resulting from fertilization. Improvements in N and P nutrition, as revealed by foliar analysis, probably accounted for much of the growth stimulation exhibited by fertilized seedlings, but reductions in the uptake of potentially phytotoxic trace elements such as Mn and Al and increases in base cation/metallic element ratios likely also contributed. The high application rate was generally preeminent in eliciting these nutritional responses. Liming induced little alteration of seedling nutrition. Impaired water relations may have caused the unfavorable responses to this treatment.     

The variation of tree-ring widths of Scots pine (Pinus sylvestris L.) affected by air pollution

Using eight populations of Scots pine growing in foothills of the Sudetes (southern Poland) as an example, the character and causes of annual ring variation in 1900–1999 were studied. The climate had a short-term effect on radial growth during the whole period investigated. A long-term decrease of radial growth occurred after 1960, but only in some localities. It was probably caused by non-climatic factors, most likely by industrial pollution. The decline of trees during that period is mainly evidenced by a high variation of width of annual rings, a small similarity of chronologies of annual ring widths, and a lack of signal years. After 1990, the tree recovery process was evident. It was most intensive in localities where the earlier stress was the most severe. Then, trees started to produce wide annual rings, homogeneity of the growth reaction increased, and the signal years began to occur.     

马尾松与黄山松天然杂种种群特性探讨

江西庐山、九岭山在黄山松垂直分布下界,发现有马尾松和黄山松的自然杂交种,通称“杉松”。其实,其叶内树脂道边生和中生兼有,且性状稳定和黄山松有质的区别。因此,我们把它拟定为新种,命名庐山松(学名待定)     

油松种子园结实技术研究

本文通过对油松球果生命史的调查,掌握了油松球果在其生长发育过程中的损失情况。提出了一整套促进油松种子园种子丰产的综合技术,使良种产量由原来的平均11．5 kg／hm2提高到26．0 kg／hm2。