Effects of stilbenes from bark of <Emphasis Type="Italic">Picea glehnii</Emphasis> (Sieb. et Zucc) and their related compounds against feeding behaviour of <Emphasis Type="Italic">Reticulitermes speratus</Emphasis> (Kolbe)

The effects of stilbene glucosides and related compounds on termite feeding behavior were investigated using paper disc methods against the subterranean termite Reticulitermes speratus. The stilbene-rich fraction and isorhapontin (3-methoxy-3,4, 5-trihydroxystilbene-3--d-glucoside) from bark extracts of Picea glehnii showed avoidance by termites in choice tests. In the no-choice tests using compounds purified from the stilbene-rich fraction, the largest feeding deterrent effect was observed for piceid (3,4,5-trihydroxystilbene-3--d-glucoside), followed by isorhapontin, and astringin (3,3,4,5-tetrahydroxystilbene-3--d-glucoside), at the concentrations from 0.63 to 2.5µmol/disc. No change in activity was observed at retentions of more than 5.0µmol/disc. When the activities of isorhapontin and its aglycone derivative (isorhapontigenin: 3-methoxy-3,4,5-trihydroxystilbene) were compared with that of taxifolin (3,3,4,5,7-pentahydroxyflavanone) in the no-choice test, the stilbenes exhibited a larger antifeedant potential. Methylation of isorhapontigenin increased its termiticidal activity.Part of this study was presented at the 32nd Annual Meeting of the International Research Group on Wood Preservation, 2001     

Light availability and understory vegetation four years after thinning in a <Emphasis Type="Italic">Larix leptolepis</Emphasis> plantation of central Korea

We measured photosynthetically active radiation (PAR) beneath the forest canopy, understory species richness and diversity, and biomass in a Larix leptolepis plantation in central Korea 4 years after thinning. Four different thinning intensities (control, 10%, 20%, and 40% stocking reduction) were applied in 1997. Mean annual intercepted PAR at 30cm and 1m above ground level was significantly different among the thinning intensities and strongly correlated with the number of stems remaining after thinning. Understory species richness and diversity were lowest in the unthinned stands and increased with thinning intensity, and there were significant correlations between the total number of understory species or diversity index (Shannons diversity index, H) and the number of stems per hectare after thinning. Also understory above-ground biomass was significantly increased with thinning intensity in both sampling months (June and August 2001). Thinning increased light inputs to the ground and resulted in higher species richness and diversity and above-ground biomass. These results suggested that light availability and understory responses to thinning at a comparable intensity are likely to last well beyond the 4 years of this study.     

Minimum distance boundary method: maximum size-density lines for unthinned <Emphasis Type="Italic">Acacia mangium</Emphasis> plantations in South Sumatra,Indonesia

A minimum-distance boundary method that will minimize the sum of distances between measured points and a fitted self-thinning lines on log–log coordinates of stand density and quadratic mean diameter was proposed in order to estimate the maximum size density line: an upper boundary of self-thinning line. The lines for A. mangium were inferred with this method using data in two areas of unthinned plantations in South Sumatra, Indonesia. Slopes of the lines were deduced as –1.63 and –1.67 within the range of 10–21cm of quadratic mean dbh. The intensity of self-thinning was examined as a rate of reduction of density in relation to dbh increment. The rates were found to be higher than the slopes in the range close to the maximum line; hence the lines inferred in this study were likely existent. Maximum basal area deduced from the size-density line was 28–30m²/ha at 12cm of dbh and then it increased up to 34–37m²/ha at 20cm of dbh.     

In vitro propagation of <Emphasis Type="Italic">Oroxylum indicum</Emphasis> Vent. a medicinally important forest tree

In vitro propagation of Oroxylum indicum Vent. was carried out using cotyledonary node explants. Among the different types of cytokinins used for culture establishment, 6-benzyladenine exhibited the best response with higher concentrations (8.87µM or above) for inducing multiple shoots. Inclusion of indole-3-acetic acid (2.85µM) into 6-benzyladenine-supplemented medium triggered a high frequency of response as well as a proliferation of shoots. The best medium for proliferation was Murashige-Skoog (MS) medium with 6-benzyladenine (8.87µM) and indole-3-acetic acid (2.85µM). However, incorporation of gibberellic acid (1.44µM) was mandatory to enhance shoot elongation. Repeated subculturing of cotyledonary node and in vitro developed nodal segments in MS medium with 6-benzyladenine (4.44µM) at 4-week intervals resulted in continuous mass multiplication of shoots without any evidence of decline. Root induction was best (91.6%) when MS strength was reduced to one-quarter and combined with -naphthalene acetic acid (2.69µM) and indole-3-acetic acid (5.71µM), with a high survival rate (70–72%) of plantlets hardened in either soil rite or soil:sand:soil rite (1:1:2).     

Constituents from the roots of <Emphasis Type="Italic">Taxus cuspidata</Emphasis>

The known propelargonidin, afzelechin-(48)-afzelechin (1), the known lignans 7-hydroxynortrachelogenin (2), epinortrachelogenin (3), nortrachelogenin (4), hydroxymatairesinol (5), allohydroxymatairesinol (6), matairesinol (7), oxomatairesinol (8), and isotaxiresinol (9), and the known taxoids taxinine M (10), taxayuntin (11), and 10-deacetyltaxol (12), and 10-deacetylbaccatin III (13) were isolated from the roots of Taxus cuspidata (Japanese yew, Taxaceae). The propelargonidin was isolated from Taxus spp. for the first time, and was detected in the roots, bark, and twigs.     

Interactions between<Emphasis Type="Italic"> Orthotomicus erosus</Emphasis> (Woll.) (Col., Scolytidae) and the Argentine ant<Emphasis Type="Italic"> Linepithema humile</Emphasis> (Mayr) (Hym., Formicidae)

Interactions occurring between Orthotomicus erosus, an economically important pine bark beetle in Portugal, and the aggressive Argentine ant Linepithema humile were investigated. Tri-trophic experimental enclosures consisting of Pinus pinaster logs, O. erosus adults and L. humile workers were set up in the field and in the laboratory. Interactions between ants and scolytids were observed and quantified in terms of the bark beetles success in colonizing the logs. The presence of L. humile did not influence the ability of O. erosus to colonize the logs, apparently due to the difficulties met by the ants in handling the bark beetles and to their inability to injure them. Thus, although abundant in many pine stands in Portugal and in spite of its aggressiveness, L. humile does not seem to affect populations of O. erosus.     

A study on some anatomical parameters of the piercing-sucking process in leaves and branches of<Emphasis Type="Italic"> Pittosporum tobira</Emphasis> L. (Pittosporaceae) infested by the cottony cushion scale,<Emphasis Type="Italic"> Icerya purchasi</Emphasis> Maskell (Homoptera: Coccina,Margarodidae)

Pittosporum tobira L. (Family Pittosporaceae) is an important plant species grown in parks and gardens in Turkey. The cottony cushion scale, Icerya purchasi Maskell (Homoptera: Coccina, Margarodidae), is an important pest of P. tobira, and causes damage mainly to the leaves, branches and stems of the host plant. In spite of the great economic importance of I. purchasi to its host plant P. tobira, information has been limited on some basic anatomical parameters of the nature of the damage to leaves and branches. The present study was, therefore, initiated to investigate the insertion and penetration of stylets into the leaves and branches of P. tobira, the length of stylets and depth of penetration in both of these tissues, and penetration of stylets into the cortex, xylem and phloem tissues and into the secretory and non-secretory canals of the leaves and branches. The results showed great variations between the leaves and branches in all the criteria observed in I. purchasi infesting P. tobira. The study found 20 whole and 23 broken mouthparts in the leaves as compared to 3 whole mouthparts and 1 broken in the branches. Length of the stylets inserted into the leaves ranged from 33.83 m to 540.93 m and into the branches from 202.85 m to 340.8 m. The stylets reached greater depths in the leaves, at 540.93 m, as compared to 498.67 m in the branches. The stylets in the leaves were associated with 12 secretory canals, but with none in the branches. It was found that three stylets reached xylem in the leaves as compared to one in the branches. Similarly, 17 stylets in the leaves reached to the phloem, but only 2 in the branches. No stylets were found in the cortex of the leaves, but one was found in the branches. In the leaves, 11 stylets reached and remained in the non-secretory canals, but none in the case of the branches.     

Abundance and distribution of<Emphasis Type="Italic"> Xylosandrus germanus</Emphasis> (Blandford 1894) (Coleoptera,Scolytidae) in Belgium: new observations and an attempt to outline its range

In Belgium, the current distribution and abundance of Xylosandrus germanus (Coleoptera, Scolytidae), a relatively new species to the Belgian fauna, is poorly known. Therefore, data on the range and population levels of this ambrosia beetle, on a regional and local scale respectively, are presented. Based on those results, the beetles range is discussed. Among the analysed biotic and abiotic factors that could influence the species settlement and population levels, climatic ones, and temperature in particular, seem to exert a crucial influence.     

Fogging can control<Emphasis Type="Italic"> Tetranychus urticae</Emphasis> on greenhouse cucumbers

The effect of a fogging system on interactions between Tetranychus urticae and Phytoseiulus persimilis was studied in two cucumber greenhouses in northern Italy. The greenhouses were divided into two compartments, one (referred to as fog area) was humidified using a fogging system and the other was not humidified (no fog area). Four cultivars were investigated: Akito and Frontera during 2000, Dinero and Jazzer during 2001. Tetranychus urticae was released on a number of plants in both compartments. The release of P. persimilis was planned in both compartments at definite T. urticae thresholds. Phytoseiid releases failed, and the colonization by other predators was scarce.Thus, the effect of the fogging system was evaluated only on T. urticae populations. During the first experimental year, spider mite populations reached low densities in the fog area of both cultivars. Higher densities were found in the no fog area, especially in late June and early July. One year later, spider mites were more abundant in the no fog area of the Dinero cultivar. On the Jazzer cultivar, where most plants were infected by powdery mildew, spider mites were less abundant and differences between the two areas were less marked. Since relative humidity values exceeding 90% (considered as effective on T. urticae) were recorded during the night when the fogging system was not active, we suggest that contact with misty water was the main factor responsible for the reduction of T. urticae populations in the fog area.     

Effect of cutting position on rooting and shoot growth of two poplar clones

One-year-old shoots from stooling beds of Populus × deltoides Walker and Populus jackii Northwest were collected in late fall to determine the effect of cutting position on rooting and growth of hardwood poplar cuttings. Cuttings with a minimum diameter of 9.0 mm were obtained from basal, middle and distal locations on the poplar shoot. Rooting and shoot growth were assessed in the greenhouse and under field conditions. Walker poplar cuttings collected from basal portions of the shoot and planted in the field had 87.6% rooting and 103.8 cm growth compared to 78.8% and 103.4 cm and 67.6% and 88.8 cm for middle and distal locations respectively. For Northwest rooting and growth under field conditions was 84.4% and 94.7 cm for basal, 78.4% and 90.5 cm for mid and 64.4% and 84.3 cm for distal locations. Rooting in the greenhouse was superior to the field. Walker cuttings had fewer roots and buds per cutting than Northwest, however, growth of Walker in the field was superior.     

Gas chromatographic and mass spectrometric (GC-MS) analysis of lignin-derived products from <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> treated in supercritical water

Sugi (Cryptomeria japonica D. Don) wood was treated with supercritical water (374°C, 22.1MPa), and fractionated into the water-soluble portion, the methanol-soluble portion, and the methanol-insoluble residue. The methanol-soluble portion mainly consisted of the lignin-derived products. To characterize the compounds in the methanol-soluble portion, gel permeation chromatographic (GPC) and gas chromatographic-mass spectrometric (GC-MS) analyses were performed. The GPC analysis indicated that the methanol-soluble portion contained lignin-derived monomeric and dimeric products. GC-MS analysis detected 31 products which were expected to be monomeric compounds, and 18 of these were identified to be guaiacol, methylguaiacol, ethylguaiacol, vinylguaiacol, eugenol, propylguaiacol, vanillin, cis-isoeugenol, homovanillin, trans-isoeugenol, acetoguaiacone, propioguaiacone, guaiacylacetone, 2-methoxy-4-(1-hydroxypropyl)phenol, homovanillic acid, 2-methoxy-4-(prop-1-en-3-one)phenol, coniferyl aldehyde, and ferulic acid. In addition, 22 dimeric products were detected, and 4 of these were believed to be compounds with biphenyl type (5-5), diphenylethane type (-1), stilbene type (-1), and phenylcoumaran type (-5) structures. These results clearly indicated that the methanol-soluble portion included various monomeric and dimeric compounds produced as a result of the cleavage of ether linkages and propyl chains of lignin.     

Characteristic Raman bands for <Emphasis Type="Italic">Artocarpus heterophyllus</Emphasis> heartwood

The Raman spectrum of Artocarpus heterophyllus heartwood, which proved to be a rich source of flavonoids, exhibited two characteristic bands, at 1247cm^–1 and 745cm^–1. The bands also appeared in the Raman spectrum of the yellow-brown needles extracted from the heartwood with methanol. Based on the Raman measurements of flavones and related compounds, it was predicted that the Raman band at 1247cm^–1 may be attributed to flavonoid-type compounds. No vibrational band corresponding to the characteristic Raman bands was observed by diffuse reflectance infrared spectroscopy. Thus, it was suggested that observation of the characteristic bands is an advantage of Fourier transform-Raman spectroscopy for nondestructive analysis of wood.     

Antioxidant activity of extracts from <Emphasis Type="Italic">Calocedrus formosana</Emphasis> leaf,bark, and heartwood

Calocedrus formosana Florin (Cupressaceae) is an endemic tree to Taiwan. To evaluate the antioxidant activity of the plant extracts from heartwood, bark, and leaf of C. formosana, assays for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide anion scavenging activities, as well as prevention of DNA strand cleavage were performed in this study. Similar IC₅₀ values against the DPPH radical were found for the heartwood and bark extracts at approximately 23µg/ml. Moreover, the heartwood extract exhibited the highest inhibitory activity against superoxide radicals among the test samples; a 2.3-fold lower value of IC₅₀ for superoxide radical inhibition was found in the heartwood extract relative to that of (+)-catechin. Much less effect on inhibition of DPPH and superoxide radicals was found from the leaf extract of C. formosana. More than 70% of superoxide radicals were inhibited in the presence of 10µg/ml heartwood extract, whereas only 15% inhibition was obtained from the leaf extract. The heartwood extract, at a dose of approximately 0.5mg/ml, apparently completely prevented the X174 supercoiled DNA cleavage induced by ultraviolet photolysis of H₂O₂, as judged by agarose gel electrophoresis. This report also suggests that the antioxidant activities of the plant extracts of C. formosana are in good correlation with their phenolic contents.     

Effects of different high constant and alternating temperatures on the development and prey consumption of <Emphasis Type="Italic">Dicyphus tamaninii</Emphasis> Wagner (Heteroptera,Miridae) with <Emphasis Type="Italic">Aphis gossypii</Emphasis> Glover (Homoptera,Aphididae) as prey

The present work aimed to study the effects of high constant and alternating temperatures on the development and prey consumption by Dicyphus tamaninii Wagner (Het., Miridae) with Aphis gossypii Glover (Hom., Aphididae) as prey.Results showed that the predator was able to successfully develop and reach the adult stage, on average, after 20.1 () and 20.6 () days at a temperature of 30 ± 1 °C with A. gossypii as prey. On the other hand, it was not able to develop at 35 ± 1 °C, here all N₁ instars used at the beginning of the experiments had died even before moulting to N₂ instar. At alternating temperatures of 25/15 ± 1 °C, the predator reached the adult stage 23.7 () and 23.5 () days after egg hatching, whereas when the temperatures were increased to 35/22 ± 1 °C, it took a significantly shorter period: 20.6 () and 20.9 () days. In general, the highest mortality occurred during the first two nymphal instars. The total percentage mortality during development from N₁ to adult stage was 30 % and 100 % at the constant temperatures 30 ± 1 °C and 35 ± 1 °C, respectively. At the alternating temperatures of 25/15 ± 1 °C, it was lowest with 16.5 %, while at 35/22 ± 1 °C, it was 20 %.The results of the experiments on prey consumption showed that an individual D. tamaninii consumed during its development to adult stage at 30 ± 1 °C an average of 442.2 (), 433.6 () aphids. At the constant temperature of 35 ± 1 °C, the average daily prey consumption started with 4 aphids and decreased continuously till it approached nil on the 9th day, where all predatory nymphs died. At the alternating temperatures of 25/15 ± 1 °C, the total prey consumption during development was, on average, 359.3 () and 297.0 () aphids, while at 35/22 ± 1 °C it was 348.5 () and 334.0 () aphids. The effect of the four temperatures on the prey consumption by D. tamaninii during the first 10 days after emergence was also studied. At a constant temperature of 30 ± 1 °C, a total of 446.4 () and 372.0 () aphids were consumed, compared to 40.6 () and 39.0 () at 35 ± 1 °C. At alternating temperatures of 25/15 ± 1 °C, the predatory adult consumed, on average, a total of 267.0 () and 207.0 () aphids. Increasing the temperature to 35/22 ± 1 °C resulted in a higher prey consumption by the adult predator, reaching 351.5 () and 267.7 () aphids over the same period.In conclusion, results indicated that D. tamaninii is a promising predator of the melon aphid at a temperature spectrum ranging from 15 ± 1 °C up to 35 ± 1 °C.     

The espinal: agroforestry systems of the mediterranean — type climate region of Chile

The Central Valley of Chile is largely occupied by a pseudo-savanna called espinal consisting of a single dominant tree species, Acacia caven (Mol.) Mol. (Leguminosae), and some 215 annuals, most of which were inadvertently introduced from the Mediterranean Basin. The probable origin and current distribution of the espino (Acacia caven) and the espinales in Chile are described. Predominant production systems of the espinal in both the semiarid and subhumid regions of Chile are outlined, with emphasis on the later region. Causes of the current low levels of productivity are discussed, and various strategies for long-term improvement of the espinal are presented.     

Studies on the population frequency of insects and mites causing galls on the leaves of the sycamore maple<Emphasis Type="Italic"> Acer pseudoplatanus</Emphasis> L. in southern Poland

Species composition of galls on the leaves of Acer pseudoplatanus L. was analysed in 2002 in three localities: the Wolski Forest, near an urban agglomeration of Kraków, the Ojców National Park and the Andrychów Forest District. A total of 12,013 galls were found. The galls were caused by six insect or mite species. The species composition of the galls was identical in the three localities. Artacris cephaloneus (Nalepa) was the most abundant species. The index of occurrence frequency and Agrells index of species co-occurrence were calculated. The index of occurrence frequency (F) value was highest in the case of A. cephaloneus (1.277) and the lowest value, i.e. 0.00005—both from the Wolski Forest. The highest value for Agrells index of species co-occurrence, i.e. 0.900, was found in the case of Eriophyes pseudoplatani Corti and Drisina glutinosa Giard (Ojców National Park), and the lowest,0.050, for D. glutinosa and Coptophylla gymnaspis (Nalepa) (Wolski Forest; Andrychów FD) and for D. glutinosa and Dasineura irregularis (Bremi) (Andrychów FD).     

Paraiso (Melia azedarach var. “Gigante”) woodlots: an agroforestry alternative for the small farmer in Paraguay

This paper describes the salient aspects and analyses the potential of the Paraiso Woodlot System, which is becoming popular as an agroforestry alternative to land use in the degraded acid sandy soils of the humid sub-tropical Guayaybi area of Paraguay. The system consists of a combination of paraiso (Melia azedarach var gigante) with other trees, especially Leucaena leucocephala, and annual crops.The fast growth habit, deep root system, addition of large quantities of organic matter through leaf and litter fall, compatibility with agricultural crops, high value of the sawlogs and production of substantial quantities of poles and firewood make paraiso an excellent species for agroforestry combination. Preliminary results of the trials indicate that the woodlots are successful and with increasing efforts of the extension agencies, they are being accepted as a viable alternative to traditional agricultural systems.Besides discussing the potential of these woodlots based on initial results, the paper identifies the constraints of the system and highlights the priority research areas.     

Nitrogen use by <Emphasis Type="Italic">Pinus densiflora</Emphasis> trees growing on a Mt. Fuji lava flow

To quantify the nitrogen (N) use by Pinus densiflora trees growing on an infertile lava surface, N pools, N requirement and N uptake through fine roots and N deposition from the atmosphere were estimated. The N requirement and the N uptake of fine roots were 55.5kgNha^–1year^–1 and 39.7kgNha^–1, respectively. Thus, the ratio of N uptake to N requirement of the fine roots was 71.5%. Including fine-root contribution, the total N requirement of the P. densiflora trees was 98.6kgNha^–1year^–1, and the total N uptake was 64.2kgNha^–1year^–1. Thus, the N uptake of the P. densiflora trees was 64.1% of the N requirement, indicating that P. densiflora trees growing on an infertile lava surface obtain some of their N from below-ground organic material layers every year and the contribution of N storage in trees for their growth is not any higher than indicated in previous reports that excluded fine-roots contribution. The wet N deposition of our research forest was only 5.8% of the N requirement of the P. densiflora trees and only 8.9% of the N uptake. Movement of the below-ground organic material layer N concentrations in the F- and L-layers coincides with needle development and fine-root growth, suggesting the possibility that P. densiflora trees extract N from the organic N of those layers for growth.     

The role of extension in agroforestry development: evidence from western Kenya

The extension strategy used by the CARE International in Kenya Agroforestry Extension Project (AEP) is described. This strategy is evaluated in terms of documented changes in farmer's agroforestry practices and the importance of AEP relative to other changes in economic incentives, institutional support, and land use and tenure rules for agroforestry. The project served mainly to increase awareness of the multipurpose potential of agroforestry, expand available technical options, and strengthen local institutions. Its community-based extension approach was more suitable for local conditions than commodity-based, training-and-visit, farming systems, or media-based extension. Projects are encouraged to tailor extension design to local circumstances, use community participation to guide extension priorities, and use extensionists as catalysts and information brokers.Research undertaken while the author was a Principal Scientist at the International Council for Research in Agroforestry, Nairobi, Kenya.     

Structure of cellulose microfibrils and the hydration effect in <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>: a small-angle X-ray scattering study

The nanometer scale structure of cell walls in sugi wood (Cryptomeria japonica D. Don) and the hydration dependence were examined by the small angle X-ray scattering technique. Disk-shaped scattering patterns were observed for sugi wood. The radial average of two-dimensional data from the cross section could supply the scattering intensity with statistical accuracy much higher than that obtained from the sector average of the streak-shaped scattering pattern, and both the scattering intensities provided similar structural information. The scattering patterns from the cross section of the wood are characterized by rhombic or cross-shaped isointensity curves for the lower q region and by circularly symmetric isointensity curves for the higher q region. This shows that the disk-shaped scattering has two different kinds of scattering origins. The microfibril radii in the cell wall were determined by fitting the model scattering function of cylindrical fibrils to the scattering data. Values of 12.3 ± 0.3 and 12.2 ± 0.3 were obtained for the fibril radii of the neighboring earlywood and latewood, respectively, in dry specimens. A drastic structural change of the cell walls was detected with increasing water content from 40% to 100%. A low q rise in the scattering intensities below 0.1^–1 became weak and changed into a flat pattern, and the rhombic isointensity curves changed to cross-shaped patterns in the two-dimensional scattering from the cross section. The calculated radii R increased from 12.2 ± 0.3 to 13.3 ± 0.1.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, Japan, April 2002