松针叶绿素—胡萝卜素软膏挥发物质化学组成的研究

松针叶绿素－胡萝卜素软膏中挥发物质含量与树种有关。分析鉴定表明：马尾松叶绿素－胡萝卜素软膏中挥发物质含量为２％－４％，从该挥发物质分离出的３０个色谱峰中鉴定出２４个化合物，其中主要成分为α－蒎烯（２１．２４％）、β－蒎烯（９．６３％）和长叶烯（２１．８３％）。鉴定出的组分占总挥发物质的９４．１２％；赤松叶绿素－胡萝卜素软膏中挥发物质的含量为３％－５％，从该挥发物质分离出的３０个色谱峰中鉴定出２４个     

松针叶绿素—胡萝卜素软膏不皂化物质化学组成的研究

松针叶绿素－胡萝卜素软膏中不皂化物质主要由于倍半萜类，二萜类，三萜类，甾族化合物，脂肪族醇和生育酚等化合物组成，分析鉴定表明，马尾松叶绿素－胡萝卜素软膏中含不抑化物质２２．３０％，其中主要成分为β－谷甾醇（１８．６５％），植醇（９．４６％）和香橙烯（７．９８％）等，共鉴定出３７个化合物，鉴定出的组分占不皂化物质总量的９８．３９％，赤松叶绿素－胡萝卜素软膏中含不皂化物质２１．２０％，其中主要成分为香     

松针叶绿素－胡萝卜素软膏中酸性物质化学组成的研究

叶绿素－胡萝卜素中酸性物质主要由脂肪酸和树脂酸组成，其中树脂酸占６０％～７５％，脂肪酸占２０％～３０％。酸性物质中各组成的含量与树种有关。分析鉴定表明，马尾松叶绿素－胡萝卜素软膏中含酸性物质２８．０％（占软膏重），从该酸中分离出３１个色谱峰，鉴定出２５个化合物，其中主要成分为海松酸（１０．９６％）、去氢机酸（１９．０６％）和油酸（８．２９％）等，鉴定出的组分占总酸量的９１．５７％；赤松叶绿素－胡萝卜素软膏中含酸性物质２２．８％（占软膏重），从该酸中分离出３１个色谱峰，鉴定出２５个化合物，其中主要成分为山达海松酸（２９．７５％）和去氢枞酸（２３．５０％）等，鉴定出的组分占总酸量的９８．２０％；樟子松叶绿素－胡萝卜素软膏中含酸性物质２６．４％（占软膏重），从该酸中分离出３１个色谱峰，鉴定出２５个化合物，其中主要成分为松叶酸（３６．０１％）、油酸（１５．６６％）和去氢枞酸（１４．８０％）等，鉴定出的组分占总酸量的９８．３０％。     

雪岭云杉针叶叶绿素—胡萝卜素软膏酸性物质化学组成的研究

雪岭云杉针叶叶绿素－胡萝卜素软膏中含酸性物质约２２％（占软膏重）,其中脂肪酸占４４．８６％,树脂酸占５２．４９％。该酸性物质经气相色谱和质谱定性,定量分析,共分离出３１个峰,鉴定出２６个化合物,被的组分占酸性物质总量的９７．３５％。其中主要成分为检酸（２１．５５％）,异海松酸（１２．８９％）、油酸（１２．０７％）、亚麻酸（７．３１％）、新纵酸（６．１０％）等。研究发现,雪岭云杉针叶叶绿素－胡萝卜素     

松针叶绿素－胡萝卜素软膏稳定性的研究

松针叶绿素－胡萝卜素软膏中含有β－胡萝卜素、维生素Ｅ、叶绿素等生物活性物质，这些物质的不足之处是稳定性较差．试验结果表明，松针叶绿素－胡萝卜素软膏在室、温避光条件下贮藏１年，不同品种产品中生物活性物质降低幅度是不同的．马尾松针叶叶绿素－胡萝卜素软膏产品中生物活性物质降低幅度分别为（％）：β－胡萝卜素１２．４，维生素Ｅ９．９，叶绿素１０．４；赤松针叶叶绿素－胡萝卜素软膏产品中生物活性物质降低幅度分别为（％）：β－胡萝卜素２５，１，维生素Ｅ．１６．４，叶绿素１２．８；樟子松针叶叶绿素－胡萝卜素软膏产品中生物活性物质降低幅度分别为（％）：β－胡萝卜素１４．８，维生素Ｅ１２．３，叶绿素２４．０．马尾松针叶叶绿素－胡萝卜素软膏产品，在室温避光条件下贮藏１５年，β－胡萝卜素损失４８．１％，维生素Ｅ损失１８．９％，叶绿素损失２９．６％．     

雪岭云杉针叶叶绿素-胡萝卜素软膏不皂化物质化学组成的研究

雪岭云杉针叶叶绿素－胡萝卜素软膏中不皂化物质主要由倍半萜类、二萜类、三萜类、甾类化合物、脂肪族醇和生育酚等化合物组成。分析鉴定表明：雪岭云杉针叶叶绿素－胡萝卜素软膏中含不皂化物质约32．0％（占软膏量），其中主要成分为云氢枞醇（10．24％）、绿叶醇（8．64％）、愈创木醇（6．89％）、β-谷甾醇（6．26％）和菜油甾醇（5．98％）等。分离共鉴定出37个化合物，占不皂化物质总量的93．26％。研究发现，雪岭云杉针叶叶绿素－胡萝卜素软膏的不皂化物质中含有较多的β－谷甾醇和菜油甾醇。     

九嶷香杉精油的化学成分

采用气相色谱－质谱－计算机（ＧＣ／ＭＳＤ）联用技术．首次研究了九嶷香杉精油的化学成分，鉴定出３８种化合物．主要成分为柏木脑（ｃｅｄｒｏｌ）２４．８％，α－蒎烯（α－ｐｉｎｅｎｅ）１７．５％，柏木烯（α－ｃｅｄｒｅｎｅ）１３．２５％，γ－荜澄茄烯（γ－ｃｅｄｉｎｅｎｅ）７．５％，柠檬烯（ｌｉｍｏｎｅｎｅ）３．５５％，榄香烯（ｅｌｅｍｅｎｅ）３．２％．其次是α－檀香烯（α－ｓａｎｔａｌｅｎｅ），β－檀香醇（β－ｓａｎｔｎｌｏｌ），月桂烯酸（ｍｙｒｃｅｎｏｌ），１．８－桉叶素（１．８－ｃｉｎｅｏｌｅ）等化合物．此外，本文还报道了在杉木精油中首次发现的２１种化合物．     

偃松针叶精油化学组成的研究

利用色谱－质谱联用分析方法，对偃松精油的化学组成进行了研究，共鉴定出４１个化学成分，主要有α－蒎烯（２４．７％）、β－蒎烯＋桧烯（４．３４％）、β－水芹烯（１２．６２％）、宁烯（６．９９％）、异松油烯（３．８６％）、乙酸松油酯（５．１６％）、γ－依兰油烯（１０．７２％）、大Ｍａｎｇ牛儿烯Ｂ（２．４３％）、杜松烯（９．１４％）等。偃松精油与樟子松、新疆云杉精油相比，β－水芹烯含量高达１２．６２％，而     

雪岭云杉针叶叶绿素—胡萝卜素软膏精油化学组成的研究

雪岭云杉针叶叶绿素－胡萝卜素软膏中含精油１．５６％，其中主要成分为乙酸冰片酯，α－荣烯，和Δ＾３－蒈烯等。分离共鉴定出２５个化合物，占精油总量的９８．１９％。研究发现，雪岭云杉针叶片叶绿素－胡萝卜软膏的精油中含有大量的乙酸冰片酯，其量超过精油总量的一半，乙酸冰片酯是制造樟脑和香精的好原料。     

羽叶栾树花气味分析

该试验应用动态顶空吸附法收集羽叶栾树花气味,结合应用气相色谱-质谱(GC-MS)技术分离鉴定其化学成分,采用离子流峰面积归一化法计算花气味中各挥发物组分的成分。结果共检测出14个组分化合物,主要物质为α-蒎烯(80.69%),β-蒎烯(5.56%),月桂烯(2.81%),对二甲苯(1.74%),(3E)-4,8-二甲基壬-1,3,7-三烯(1.13%)。     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Biogeochemical impacts of clearfelling and reforestation on blanket-peatland streams: II. major ions and dissolved organic carbon

Streams and drains in blanket-peatland forest in western Ireland were sampled weekly over 5 years, 1996–2000, using continuous, depth-proportional passive sampling. Analysis was for pH, alkalinity by Gran titration, anions by IC, metals by ICP, aluminium speciation by loaded-resin exchange, and dissolved organic carbon (DOC) by absorbance at 320 nm.

Effects of felling are identified graphically from two forest drains whose catchments (both about 1 ha) were clearfelled, and partial clearfelling of one larger catchment (somewhat over 1 km²), in summer 1999. Calcium concentrations and alkalinity were increased in the drain- and streamwater from the felled areas. The pH was increased in drains, while in the larger stream, pH range decreased while the mean increased. Phosphorus increased markedly with clearfell, in the absence of recent fertilising, and also increased with fertilising; these results are reported in an accompanying paper. Ammonium-nitrogen concentrations were increased in the two drains with felling, and temporarily decreased in the larger stream. Nitrate increased in some cases. Potassium and manganese concentrations also increased. Concentrations of DOC and organic monomeric aluminium increased gradually, subject to a continuing strong annual cycle. There were no clearfelling effects on concentrations of solphate, suspended solids or inorganic monomeric aluminium. In the two drains (fully clearfelled), concentrations of sodium, chloride and magnesium, and conductivity, were all reduced after felling. Fertilising effects other than for phosphorus were indistinct.

Effects of the combined clearfell–reforestation treatment were testable statistically, using randomised intervention analysis, between two larger streams (1 km²) as a treatment–control comparison. There were statistically significant positive responses in streamwater concentrations of nitrate, potassium, calcium, DOC and aluminium fractions. The implications for management practice depend on whether the loss of nutrients is sustainable for future crop productivity, and whether critical limits and loads of receiving ecosystems are exceeded.     

Effect of Drought on Growth and Mortality of Actively Growing Norway Spruce Container Seedlings Planted in Summer

Survival, root egress and height growth of 13-month-old actively growing Norway spruce ( Picea abies (L.) Karst.) container seedlings exposed to preplanting drying treatments (0, 4, and 8 days) and postplanting drought periods (1, 2, 3, and 4 weeks) were studied in the field between 5 July and 18 August 1999. The mortality of seedlings increased and the height growth and root egress decreased throughout the postplanting drought period. Postplanting performance was also affected by preplanting drying treatments. The results indicate that no risk of excessive mortality and growth restrictions occurs when actively growing seedlings are planted in summer, provided that seedlings are well watered before planting and the drought period does not exceed 3 weeks.     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.     

qPCR quantification of Ophiognomonia clavigignenti‐juglandacearum from infected butternut trees under different release treatments

The use of a molecular assay for quantifying conidia of Ophiognomonia clavigignenti‐juglandacearum, the fungal pathogen responsible of butternut canker, was investigated. Purified DNA from conidia collected on glass fibre filters of a passive rain collectors was quantified using a TaqMan real‐time quantitative polymerase chain reaction (qPCR) assay. The qPCR assay could specifically discriminate the target species from all other North American known species of Ophiognomonia, and it was sensitive enough to repeatedly detect one conidium. A linear relationship between numbers of conidia and qPCR C_t values was determined, and used to assess the sporulation of the pathogen under trees that were released to promote their vigour. In total, 977 samples of field‐captured conidia from 49 trees, at two locations, and from two successive growing seasons were analysed. No significant difference of sporulation was observed under control and release treatments. However, our results demonstrated that qPCR assay was reliable for detecting and quantifying O. clavigignenti‐juglandacearum from environmental samples, which will be useful to assess further control methods for this disease.     

The potential of alley cropping in improvement of cultivation systems in the high rainfall areas of Zambia I. Chitemene and Fundikila

Three trials investigating the potential of alley cropping to improve the traditional systems of cultivation, chitemene and fundikila, in the Northern Province of Zambia are described. Flemingia congesta, Tephrosia vogelii, and Sesbania sesban, were grown in association with finger millet, groundnut, cowpea, and maize in various traditional cropping sequences. The indigenous species Tephrosia vogelii and Sesbania sesban were not able to withstand repeated pruning and the long following dry season, and were replaced with Calliandra calothyrsus, and Cassia spectabilis.Over a four year period, there was no benefit by alley cropping with any of the tree species on crop yields, and yields in alley crop treatments even dropped significantly below the control treatments in the fourth year, casting doubt on the potential of alley cropping for sustainable production. There was also no consistent effect on soil chemical characteristics in any of the trials. It was suggested that this lack of beneficial response to alley cropping was due to low tree biomass production low quality of prunings, and an inappropriate cropping sequence. There was no evidence that alley cropping contributed to enhanced nutrient recycling, despite substantial localised pools of soil nutrients, particularly in the chitemene, with which recycling could potentially occur.     

Toxicity of biocide GCSC-BtA on arthropod pests under different temperature conditions

The present research dealt with the toxicity of GCSC-BtA (Germany–China Scientific Cooperation-Bacillus thuringiensis-Abamectin), a new type biocide developed by conjugating a toxin from Bacillus thuringiensis (B.t.) with Abamectin from Streptomyces avermitilis, on arthropod pests under different temperature conditions. The results showed that GCSC-BtA possessed higher toxicity than B.t. crystal, Abamectin or Cypermethrin, with pest mortalities of 97.9, 93.7, 96.4, 82.3 and 96.7% for Tetranychus cinnabarinus (Boisd.) (Acari, Tetranychidae), Frankliniella occidentalis Pergande (Thys., Thripidae), Aphis fabae Scopoli (Hom., Aphididae), Plutella xylostella (L.) (Lep., Plutellidae) and Cameraria ohridella Deschka et Dimić (Lep., Gracillariidae), respectively. Toxicities of GCSC-BtA to T. cinnabarinus and P. xylostella decreased significantly at the older developmental stage with an exception that egg stage had the highest tolerance, in which LC₅₀s of GCSC-BtA were 0.0001, 0.0019 and 0.0708 mg/ml for nymph, adult and egg of T. cinnabarinus, and that 0.0399, 0.2035 and 0.9033 mg/ml for the 2nd instar larvae, 4th instar larvae and egg of P. xylostella, respectively. Also, the biocide was more effective to the lower stage of A. fabae than the higher one with LC₅₀s of 0.0023, 0.0086 and 0.0171 mg/ml against 1st instar nymph, 3rd instar nymph and adult, respectively. In general, toxicity of the new type of biocide was positively related to temperature against all the tested pests, except against T. cinnabarinus, where it was almost similar at the three temperature conditions. GCSC-BtA displayed significantly lower toxicities at 15/20°C than 20/25°C or 25/30°C against F. occidentalis, A. fabae, P. xylostella and C. ohridella. However, no significant difference was found in the toxicities against F. occidentalis, A. fabae and C. ohridella above 20°C, whereas toxicity against P. xylostella increased as temperature raised. Therefore, to achieve higher efficacy in the field, application rate and time should be devised according to these factors.