Light intensity affects the growth and flavonol biosynthesis of Ginkgo (Ginkgo biloba L.)

Response of growth and secondary metabolites to light intensity are useful measurements to determine suitable silviculture treatments for the cultivation of medicinal plants. Here, we analyzed the growth, flavonols (total flavonol, quercetin, kaempferol, and isorhamnetin) content, flavonols yield per plant, and expression of flavonoid biosynthesis-related genes in 2-year Ginkgo (Ginkgo biloba L.) seedlings at four different light intensities (100, 76, 40, and 25 % of full sunlight) in a greenhouse setting. Across all light intensities, the 76 % sunlight treatment produced the highest growth of total biomass, root, stem, and leaf, indicating negative effects of either fulllight or heavy shading on Ginkgo seedling development. Both flavonols (total flavonol, quercetin, kaempferol, and isorhamnetin) content and expression of flavonoid biosynthesis-related genes [PAL (Phenylalanine ammonia-lyase), CHS (Chalcone synthase), F3H (Flavanone 3-hydroxylase), and FLS (Flavonol synthase)] in leaves were highest under 100 % sunlight, suggesting that full sunlight promotes the expression of flavonoid biosynthesis-related genes and increases flavonoid biosynthesis. The highest and lowest flavonol contents were found in leaves and stems, respectively. The 76 % sunlight treatment produced the highest flavonols yield while the 100 % sunlight produced the highest flavonoids content in leaves, indicating that flavonol production per unit land area depends not only flavonol content but also biomass. Overall, in order to achieve the highest flavonols yield per area in Ginkgo leaf-harvesting plantations, it is important to manipulate light conditions of field.     

Circumferential variation of heartwood and stem quality in maritime pine stems

Maritime pine (Pinus pinaster Ait.) is an important timber and pulpwood species covering about 4 million ha in Portugal, Spain and France. This work studied the cross-sectional distribution of heartwood and sapwood along the stem using 3D modelling on 20 trees. The target was to assess the potential of this species for the industrial production of heartwood sawn products. The maritime pine stems were characterized by wide sapwood of 10 cm, in average, and the presence of heartwood at all height levels with constant diameter up to 35 % tree height, decreasing afterwards. In the radial section, the heartwood follows a circumferential-like shape which changes along the stem. Pith eccentricity index values were low and homogeneous regarding to stem and higher for heartwood. Heartwood cross-sectional shape was constant up to 45 % of total height of the tree and more elongated upwards. The constant heartwood diameter, low taper and pith eccentricity index, and an approximate circular shape up to 10 m height indicated these species’ potential to produce solid wood products made out of heartwood.     

Evaluation of microbial and chemical insecticides for the control ofSpodoptera exigua (Lep., Noctuidae) on soybean plants

Field experiments have been carried out to evaluate the potency of the biological control agentBacillus thuringiensis (Dipel), the pyrethroid Fenvalerate and their combinations for the control of the lesser cotton leafwormSpodoptera exigua on soybeans in Qualubia governorate. Molasses was combined with all treatments to enhance their effectiveness. One spray application with either Dipel or Fenvalerate showed an obvious reduction in larval counts ofS. exigua, associated with a significant increase in the crop yield but in varying degrees, in correlation with the tested dose. Treatments with combinations of both biological and chemical insecticides at the lowest tested doses (62 g ofB. t. +50 ml of Fenvalerate/feddan) showed to be highly potential, and caused 2.8 fold increase in the crop yield. It may be recommended that a combination of both preparations may be used for the control ofS. exigua.     

Impact of local slope and aspect assessed from LiDAR records on tree diameter in radiata pine (Pinus radiata D. Don) plantations

Context

Reliable information on tree stem diameter variation at local spatial scales and on the factors controlling it could potentially lead to improved biomass estimation over pine plantations.

Aims

This study addressed the relationship between local topography and tree diameter at breast height (DBH) within two even-aged radiata pine plantation sites in New South Wales, Australia.

Methods

A total of 85 plots were established, and 1,302 trees were sampled from the two sites. Airborne light detection and ranging (LiDAR) was used to derive slope and aspect and to link them to each individual tree.

Results

The results showed a significant relationship between DBH and local topography factors. At both sites, trees on slopes below 20° and on southerly aspects displayed significantly larger DBHs than trees on steeper slopes and northerly aspects. Older trees with similar heights also exhibited a significant relationship between DBH and aspect factor, where greater DBHs were found on southerly aspects.

Conclusions

The observed correlation between tree DBH and LiDAR-derived slope and aspect could contribute to the development of improved biomass estimation approaches in pine plantations. These topographical variables are easily attained with airborne LiDAR, and they could potentially improve DBH predictions in resource inventories (e.g. stand volume or biomass) and support field sampling design.     

Severe outbreaks of the ash sawflyTomostethus nigritus F. (Hymenoptera: Tenthredinidae) on ornamental trees in oslo

During spring and summer 1990 observations on the biology of the ash sawfly,Tomostethus nigritus F. were made and control options discussed. The sawfly overwinters as an co- or pronymph in the soil, and pupates in earlys spring. The tlight period lasted for about 3 weeks. The larvae fed on the leaves till June. Injecting the systemic insecticide Carbicron 50 SCW (Dicrotophos) was successful.     

Important properties of bamboo pellets to be used as commercial solid fuel in China

Bamboo is a type of biomass material and has great potential as a bio-energy resource of the future in China. Some properties of bamboo pellets, length, diameter, moisture content (MC), particle density, bulk density, durability, fine content, ash, gross calorific value, combustion rate and heat release rate, were determined and the effects of MC and particle size (PS) on these properties were investigated in this research. The results showed that bamboo pellets will be the proposed new biomass solid fuel and have the potential to be developed as commercial pellets. All properties of bamboo pellets met the requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified Fuel. The gross calorific value of bamboo pellets also met the minimum requirement for making commercial pellets according to DIN 51731 (>17,500 J/g). The effects of MC on length, diameter, MC, particle density and bulk density were significant at p = 0.05. There were no significant differences between PS and all properties of bamboo pellets. Due to higher MC and larger PS, bamboo pellets exhibited higher combustion rates and heat release rates. This research represents an initial stage in the study of bamboo pellets, and its objectives provide guidelines for further research.     

Mechanical properties of kenaf fiber–cement composites containing kenaf gamma-ray grafted with acrylamide

Kenaf fibers have excellent properties and possess the potential to be outstanding reinforcing fillers in cement. The grafting of acrylamide to kenaf fibers is important in improving the compatibility between the fibers and the cement. Acrylamide was grafted onto kenaf fibers using gamma-ray radiation. The radiation dose ranged from 20 to 100 kGy, and the dose rate was 10 kGy/h. The degree of grafting increased with increased radiation doses. FT-IR analysis revealed an increase in amide content after gamma-ray-radiation-induced grafting, further evincing the attachment of acrylamide to the kenaf fibers. SEM images showed evidence of acrylamide grafting to the fiber surface. Contact angle measurements on individual fibers taken before and after grafting demonstrated changes in wettability. The mechanical properties of the gamma-ray-grafted kenaf fiber–cement composites were superior to those of the ungrafted kenaf fiber–cement specimens.     

Forecasting of outbreaks ofSpodoptera exempta Wik. (Lep., Noctuidae) based on sex-pheromone trapping in the republic of Yemen

Spodoptera exempta (Wlk.) is recorded every year in the Republic of Yemen. Based on the use of pheromone traps, a very simple but effectively applicable monitoring and forecasting system was developed. Areas from which infestations have been reported and the frequency of attacks are mapped in detail. The monthly distributions and frequencies of incidence are presented in two tables. The range of recordedS. exempta moths is illustrated and the number of outbreaks for the last 32 years described.     

Near-infrared spectroscopy and wavelength selection for estimating basic density in Mimosa tenuiflora [Willd.] Poiret wood

The aim of the present work was to estimate the basic wood density of Mimosa tenuiflora by using near-infrared spectroscopy (NIRS). Fifty-eight wood samples representing sapwood, heartwood and pith were evaluated by gravimetric method and NIRS together with wavelength selection methods. A comparison was made among several multivariate calibration techniques and algorithms for preprocessing and variable selection of data, including full-spectrum partial least squares (PLS), interval PLS, backward interval PLS, synergy interval PLS, genetic algorithm-PLS and successive projections algorithm for interval partial least squares (iSPA–PLS). Finally, the results obtained using iSPA–PLS model for the root mean square error of calibration and prediction were 0.0383 and 0.0166 g/cm³, respectively. A t-test was performed to compare the results of the models with each other and with a reference method. NIRS and iSPA–PLS can be used to predict basic density of Mimosa tenuiflora [Willd.] Poiret wood samples rapidly. In addition, the basic density could also be predicted with only 17 wavelengths in the range from 2,090 to 2,208 nm that should allow for measurement of this parameter using handheld NIR spectrometer.     

Digital radiography (DR) and imaging analysis for evaluating the penetration and distribution of organic substances used in wood conservation

Consolidation treatments are commonly employed in museum conservation studios for treating biologically deteriorated wooden cultural heritage objects. Impregnation using either a solvent/resin or a polymerizing system is an example of such an intervention, which is often difficult to describe in terms of its behavior within the object’s structure. A new simple method has been devised to evaluate the effectiveness of these impregnation treatments in terms of spatial distribution of consolidant solution. A combination of digital radiography and imaging analysis has permitted to evaluate the degree of penetration of a consolidant and to determine its location within the artifact by studying the X-ray images taken before, during, and after treatment. The adequacy of polymer solutions or their effectiveness as wood consolidants is properties which are often difficult to investigate due to limited visual access to the interior of the object. The proposed method provides an alternative way of studying these parameters through analysis of X-ray attenuation recorded on two images: taken before and after the conservation treatment. The resulting image is then converted into a two-dimensional map of consolidation agent within the object using a straightforward calibration procedure.     

Characterization of black locust (Robinia pseudoacacia L.) heartwood extractives: identification of resveratrol and piceatannol

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less durability against fungi decay, which could be attributed to lower extractive content. In order to elucidate this idea, extractives from mature and juvenile heartwoods of black locust trees were investigated. Results showed that extractive and phenolic contents were higher in mature than in juvenile heartwoods. The identification of phenolic compounds by UPLC–DAD–MS/MS revealed, for the first time, the presence of resveratrol and piceatannol. These two stilbenes as well as the flavonoid dihydrorobinetin were present at the highest level in mature heartwood, and as they are known antifungals, they could account for the great durability of mature heartwood. The stilbenes were detected in significant amounts particularly in mature heartwood where piceatannol reached a level tenfold higher than that reported for Japanese knotweed roots, the primary natural source of these stilbenes, whereas resveratrol level was comparable with reported values. As resveratrol and piceatannol receive increasing demand for nutraceutical, cosmetic and, possibly, pharmaceutical purposes, due to their beneficial health effects, this study underlines the use of R. pseudoacacia as a promising sustainable and economical source of resveratrol and piceatannol.     

Effects of crown length on indole acetic acid (IAA) amounts in cambial region tissues in lower and upper trunks of sugi cultivars (Cryptomeria japonica) in September

Indole acetic acid (IAA) was believed to be an important regulator in xylem formation in conifers. However, few studies have been done on the endogenous amount of IAA in cambial region tissues in sugi (Cryptomeria japonica) trees. In this study, we report the IAA amounts in the lower and upper trunk of mature sugi cultivars (Kumotoshi, Yaichi and Obiaka) in September, and the effects of growth traits on the IAA amounts. The effect of height position (lower or upper trunk) on IAA amounts was found to be larger than that of genetic variation (Kumotoshi, Yaichi or Obiaka) by two-way ANOVA. There was no significant interaction effect (genetic variation × height position). The IAA amounts of all trees varied from 3 to 42 ng/cm² at the lower trunk and 9 to 47 ng/cm² at the upper trunk. Crown length and distance from crown base had significant positive and negative effects on IAA amounts in the trunk of sugi cultivars, respectively. Distance from crown base had a larger effect on IAA amounts than crown length. In Yaichi, taller trees had larger IAA amounts at both the lower and upper trunk.     

Impact of temperature and nutrition on the toxicity of the insecticide λ-cyhalothrin in full-lifecycle tests with the target mosquito species Aedes albopictus and Culex pipiens

The global spread of the Asian tiger mosquito Aedes albopictus, an urban pest as well as a vector for arboviruses, is a threat for public health. As control measures include the use of insecticides such as the pyrethroid λ-cyhalothrin, it is crucial to assess their efficiency and their potential impact on the biodiversity especially under climate change conditions. To evaluate the environmental risk, biotests are well established for non-target organisms but not yet for mosquitoes. We therefore developed a full-lifecycle biotest for mosquitoes kept under quarantine conditions based on the OECD guideline 219. Therewith we tested the effect of temperature and nutrition on the ecotoxicological response to λ-cyhalothrin on the mosquitoes Ae. albopictus and Culex pipiens by assessing sublethal and life history parameters. The efficiency of λ-cyhalothrin decreased in both mosquito species with increasing temperature and changed with feeding protocol. At effective concentrations for potential mosquito control in surface waters, λ-cyhalothrin poses a high risk for indigenous aquatic key role species inhabiting the same microhabitats. Those aspects should to be taken into account in vector control strategies.     

Conservation of a Tropical Wet Semi-evergreen Forest Ecosystem by an Indigenous Community in the Bandarban Hill District of Bangladesh: The Role of Intervention

Indigenous communities in the Chittagong Hill Tracts (CHT) of Bangladesh had been conserving small patch of forests, commonly called village common forests (VCFs), especially for drinking water and non-timber forest produce. The size of VCFs has been decreasing, due to increasing population and conversion of forests for shifting cultivation. To restore the degraded forest resources and conserve the forest ecosystems in the VCF of the CHT, an intervention was undertaken in Bandarban, Bangladesh by Arannayk Foundation, an organization established jointly by the Government of Bangladesh and the United States of America. A training program on leadership, organizational development and alternative income generating activities was implemented to build the capacity of the members of the VCF management committee. The impact of the interventions was measured at the end of third year. Incomes of VCF-dependent communities were found to increase with resultant reduction of their dependence on VCFs. The intervention encouraged women’s participation in forest management and facilitated a written format of the constitution of the VCF management. The study identified that more training and awareness-raising activities are needed to ensure sustainability of the interventions. Mobilizing funds for the communities for sustainable alternative livelihoods was found effective. Appropriate compensation for conservation was found to make the restoration and conservation activities sustainable.     

Distribution and persistence ofSteinernema spp. andHeterorhabditis spp. (Nematodes) under different field conditions

The vertical and horizontal distribution, as well as the persistence ofSteinernema glaseri, S. carpocapsae (1192, I 100 and Mexican strains),Heterorhabditis bacteriophora, H. heliothidis andHeterorhabditis sp. were studied in three different soil types under field conditions. The presence of infective juveniles in soil samples taken at various depths was assessed usingGalleria mellonella larvae as baits for the nematodes. Results show that all tested nematodes had a similar pattern of vertical distribution. On the other hand,Heterorhabditis spp. were significantly more persistent thanSteinernema spp. in all soil types. As for the horizontal dispersal, none of the nematodes were ever found outside the treated plots, indicating that most of the juveniles remained near the point of application.     

Failure of black cohosh (Actaea racemosa L.) rhizome transplants: potential causes and forest farming implications

Black cohosh (Actaea racemosa L.) rhizomes are harvested extensively from eastern North American forests and sold worldwide for treatment of menopausal symptoms. While forest farming is encouraged to reduce wild-harvest impacts, little information is available to aid landowners in successfully cultivating black cohosh. This study examined survival and multi-year growth of 200 black cohosh rhizomes collected from an Appalachian deciduous forest and transplanted to a similar forest type. By the second year after transplant, fewer than 40 % of rhizomes produced above-ground growth and mean rhizome biomass declined by more than 50 %. Shoot biomass was the greatest predictor of below-ground biomass; however, leaf area provided a reasonable, non-destructive means of estimating this commercially-important biomass. Our results suggest that pre-transplant rhizome condition is particularly important to transplant success. Low biomass, lack of roots, and fungal infection all were associated with reduced plant survival. Based on this and associated studies, we recommend careful site selection for propagation, including circumneutral or lime-amended soils and light to moderate shading. Well-drained soil appears particularly important to discourage fungal infection. Understanding conditions for successful transplanting of black cohosh rhizomes can improve forest farming and contribute to sustainable management of this and other non-timber forest products.     

Control of the American dog tick,Dermacentor variabilis Say (Acarina: Ixodidae)

In a 4 ha area, of which 1/3 was meadow vole habitat, the old vole runways were spot treated in early spring with a 1% spray of flowable Sevin^® 4F (42% AI) on ca 4 m centers. New runways, as noted, were treated in June. The application averaged 60 ml of Sevin^® 4F/ha. The spring adult cohort ofDermacentor variabilis was <10% of that usually expected. These adults had been exposed to this treatment the previous year as spring larvae and summer nymphs. The reduction of the adult population occurred in a season of heavy infestation. This treatment is not labor intensive and requires only a minimum of pesticide because it is directed to its target, the attached immatures, by the behavior of the field mice. It should be noted that all the small rodent hosts of the immatures use the vole runways.     

Reaction behavior of wood in an ionic liquid, 1-ethylpyridinium bromide

The reactions of Japanese cedar and Japanese beech in a pyridinium-based ionic liquid, 1-ethylpyridinium bromide ([EtPy][Br]) were studied. Japanese beech was more easily liquefied than Japanese cedar. Hemicellulose is liquefied rapidly, lignin more slowly, while cellulose is partially liquefied. X-ray diffraction analyses on the [EtPy][Br]-insoluble residues revealed that the crystalline structure of cellulose is maintained even after treatment. The difference in liquefaction can be explained by chemical structural differences between softwood and hardwood lignins and hemicelluloses.     

Temperature has more effects than soil moisture on biosynthesis of flavonoids in Ginkgo (Ginkgo biloba L.) leaves

The flavonoids content and its composition in Ginkgo (Ginkgo biloba L.) leaves are affected by environmental factors such as temperature and soil moisture. Here we performed experiments in phytotron using 2-year-old Ginkgo seedlings to explore the effects of temperature and soil moisture on flavonoids content, enzymes related to flavonoids biosynthesis such as phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and p-coumarate CoA ligase (4CL), soluble sugar and protein content. We found that temperature and lower soil moisture had significant effects on these parameters. The effects of temperature on flavonoids content, the activity of C4H and 4CL and soluble sugar content were greater than that of soil moisture. The total flavonoid content, the activity of PAL, C4H and 4CL, soluble sugar content were higher in lower temperature regime 15 °C (daytime)/5 °C (nighttime) and lower soil moisture (30–35 % of field capacity), but higher temperature was beneficial to the accumulation of soluble protein. This indicates that increasing of soluble sugar content and the activity of PAL, C4H and 4CL are beneficial to flavonoids biosynthesis and accumulation in the Ginkgo leaves, while increasing of soluble protein is adverse to flavonoids biosynthesis. Because lower temperature and soil moisture are favorable to flavonoids biosynthesis, we can take some silvicultural steps to increase flavonoids production in Ginkgo plantation, such as establishing leaf-harvest plantation at lower temperature zone, reducing irrigating before harvesting leaves.     

Population fluctuations on parasites ofLepidosaphes beckii Newm. andCeroplastes floridensis Comst.

Lepidosaphes beckii Newm. (Hom., Diaspididae) andCeroplastes floridensis Comst. (Hom., Coccidae), are dominant pests on citrus trees (Citrus sinensis), in Alexandria district. The population fluctuations of the parasites of both insects were studied during a whole year. Six species of hymenopterous primary parasites together with one secondary parasite were found onL. beckii. These species wereAphytis lepidosaphes Compere,A. bispanicus Compere,Encarsia (Prospaltella) spp.,Aspidiotiphagus citrinus Craw,Aphytis lingnanensis Compere, and the secondary parasiteMarietta javensis Howard.A. lepidosaphes was the most common parasite onL. beckii. ConcerningC. floridensis, four species of hymenopterous parasites were found, namelyTetrastichus ceroplastae (Girault),Aspidiotiphagus citrinus Craw,Metophycus flavus (Howard), andMicroterys flavus (Howard).