Mortality and Diameter Growth in Mountain Ash Defoliated by Phasmatids

Mortality of mountain ash defoliated by phasmatids during 1960–61 and again in 1962–63 reached 83 per cent within two years of the second defoliation. For two years after the second defoliation, the surviving trees decreased in diameter; thereafter, positive increment was recorded but only for the least affected trees.     

The Growth of Radiata Pine On Lateritic Soils at Second Valley,South Australia

Factors involved in the growth of P. radiata (D. Don) on soils of a lateritic landscape have been examined by soil and foliar analysis and the measurement of ring width; this has given an appraisal of factors influencing growth in the past and at the present time.

Perched water tables, which often occurred in winter on the plateau where there were lateritic podzolic soils, did not depress growth. The addition of phosphate was essential, with responses lasting for about 8 years with superphosphate. Regression relationships between the annual growth increment (ΔV in cubic feet) and foliar levels of nitrogen (N) and phosphorus (P) were found for three different foliar sampling positions; these relationships had the form:

ΔV = 4.5%P + 0.28%N—0.47.

Considerable variation was found in the foliar levels of nitrogen, phosphorus, copper, zinc, boron, nickel, molybdenum, chromium and ash for different sample positions within the tree. Preliminary responses to nickel, copper and nitrogen were obtained on 15-year-old trees well supplied with phosphorus. Advisory foliar levels for nitrogen and phosphorus are given.     

OBITUARIES

A stand model to generate alternative management strategies for a long range planning model has been constructed for intensively-managed radiata pine plantations in Gippsland, Victoria. The model can be used to evaluate different intensities of silviculture as well as to provide estimates of future production.     

Early Growth of Radiata Pine in Relation to a Land Classification System on Forestier Peninsula in Tasmania

A land classification dividing the forest area of Forestier Peninsula in south eastern Tasmania into two land systems, the Blackman land system and the Murdunna land system, and several land units is described. Results from a trial to evaluate four component units of the land classification for establishment of a radiata pine plantation indicate different growth rates, nutrient deficiencies and responses on different units. On three of the four units there was a growth response to application of phosphorus and an interaction of nitrogen and phosphorus. On the fourth unit there was no growth response to application of phosphorus alone but there was a response to application of nitrogen and phosphorus together. Without treatment, radiata pine trees growing on the Murdunna land system had extremely low foliar concentrations of phosphorus, nitrogen and copper. On only one land unit was growth satisfactory without fertilizer.     

Continuing Education for Forest Managers

Changing community attitudes are leading to a wider acceptance of the need for continuing education. Universities offering professional degree courses have a responsibility for continuing education in the subject-areas covered by their undergraduate curricula, which could be discharged in one or more ways, e.g. short refresher courses to keep practitioners abreast of developing theory and practice, or longer recurrent study programs leading to further formal qualifications. However the responsibility for continuing education must be shared by employing agencies and professional societies. The Institute of Foresters in particular should be concerned with ensuring that adequate opportunities exist for further education of its corporate membership. The needs and likely demands of foresters for continuing education are considered, and suggestions outlined for future developments.     

An Examination of Ashbed Soils Growing Radiata Pine in Gippsland Victoria

Ashbed soils on which pines had been planted after the native eucalypt vegetation had been cleared, heaped and burnt were compared with non-ashbed soils from adjacent areas which had been cleared and planted.

Tree growth, soil chemical properties and foliar nutrient levels were examined at sites of varying age and a pot trial was established to complement the field trials.

Tree measurements at age 12 years revealed that radiata pine (Pinus radiata D.Don) on ashbed soils had produced 50 percent more timber than stands on adjacent non ashbed soils.

Height growth differences favoured the ashbed sites to the greatest extent at age 5 to 6 years, but decreased and were not signficant at age 12 years.

The ashbed soils had significantly higher percentages of total nitrogen, phosphorus, potassium, manganese and soluble salts in the top 10 inches of soil; the pH of the ashbed soil was also higher by one unit.

Trees on ash bed soils had correspondingly higher percentage of phosphorus and potassium in their foliage compared with trees on adjacent non-ashbed soils but these differences declined with age.

Seedlings grown in pots of ashbed soil also had higher percentages of phosphorus and potassium in their foliage than seedlings in pots of non ashbed soil.     

Book Review

The relationship between variation in wood shrinkage and cellulose crystallite width determined by X-ray diffraction was assessed using SilviScan-2 (a system developed at CSIRO for rapid assessment of wood microstructure). Cellulose crystallite width, density and microfibril angle were determined for 600μm wide zones on small wood samples with known tangential shrinkage. The tangential shrinkage measurements included shrinkage to 12% moisture content after reconditioning (MC AR); and a shrinkage differential calculated from tangential shrinkage to 12% MC AR recorded for each zone; and the minimum shrinkage recorded in adjacent wood of similar cambial age. Spearman correlations and forward stepwise regressions showed that the cellulose crystallite width was a good predictor of the shrinkage measures and that density was a minor predictor. Together, cellulose crystallite width and density could explain 75% of the variation in tangential shrinkage for randomly selected locations throughout the tree, and 87% of the variation in tangential shrinkage in samples selected from the lower 5% of tree height. The results suggest that SilviScan-2 can be used to predict tangential shrinkage during drying in increment cores, and may therefore be useful in developing nondestructive sampling strategies in tree improvement programs for E. globulus.     

宫颈癌HeLa细胞特异性结合肽的筛选及鉴定

背景与目的:宫颈癌的分子靶向治疗具有很好的疗效,同时可以显著减少抗癌药物对人体自身的损伤,因此备受关注。本研究利用噬菌体体内展示技术筛选及鉴定宫颈癌特异性结合肽,将有可能成为化疗药物的靶向载体,为宫颈癌靶向药物治疗奠定基础。方法:体外培养宫颈癌HeLa细胞接种裸鼠,建立肿瘤动物模型。将随机肽库尾静脉注入裸鼠体内,循环15 min,心脏灌注后回收肿瘤组织噬菌体扩增、纯化并以此作为起始物进行第2轮的筛选,如此进行3轮体内筛选后挑取噬菌体克隆,进行免疫组化及ELISA实验,初步鉴定噬菌体克隆对宫颈癌细胞的亲和力及特异性,并将具有强亲和力的克隆进行测序。结果:ELISA结果显示,随机挑选10个噬菌体单克隆中8个克隆对HeLa细胞具有很强的亲和力,将这8个克隆进行测序,获得相同短肽序列LLRSTGF。结论:利用噬菌体展示技术筛选出与宫颈癌细胞HeLa特异性结合的短肽,进一步与化疗药物结合,为宫颈癌靶向治疗提供新的方法。