Antifungal activity of the stem bark of Ailanthus excelsa

The methanol extract of stem barks of Alianthus excelsa was partitioned with chloroform. The chloroform extract showed fungistatic and fungicidal activity against Aspergillus niger, A. fumigatus, Penicillium frequentence, P. notatum and Botrytis cinerea.     

Generalized allometric volume and biomass equations for some tree species in Europe

Since biomass is one of the key variables in ecosystem studies, widespread effort has aimed to facilitating its estimation. Numerous stand-specific volume and biomass equations are available, but these cannot be used for scaling up biomass to the regional level where several age-classes and structural types of stands coexist. Therefore simplified generalized volume and biomass equations are needed. In the present study, generalized biomass and volume regression equations were developed for the main tree species in Europe. These equations were based on data compiled from several published studies and are syntheses of the published equations. The results show that these generalized equations explain 64–99% of the variation in values predicted by the original published equations, with higher values for stem than for crown components.

The effect of bark decortication for hiwada production on xylem and phloem formation in Chamaecyparis obtusa

Of all plant materials used to cover the roofs of traditional Japanese buildings, Japanese cypress (Chamaecyparis obtusa) bark, hiwada, has the longest service life and has been used from ancient times. However, wood and bark properties after hiwada harvest have not been evaluated in detail. We studied whether decortication for hiwada production in winter affected xylem and phloem formation. Decorticated trees still preserved all inner bark and part of the outer bark, and both decorticated and control trees had similar annual ring structures at all stem heights in the xylem and phloem. In both xylem and inner bark, no significant difference in ring width at any stem height was found between annual rings before and after decortication. Thus, this study revealed that the decortication of bark for hiwada production does not affect the formation of xylem and the inner and outer bark if decortication is carried out by highly skilled workers in winter.     

Chemical constituents from Gmelina arborea bark and their antioxidant activity

Gmelina arborea Roxb. is a fast-growing species and is known to have been used in traditional Indian medicine. Chemical constituents from the bark have not been reported, although some chemical constituents from part of this plant (heartwood, leaf, and root) are known. In this study, the bark meal was successively extracted with acetone and methanol. Fractionation of the acetone extract with n-hexane, diethyl ether, and ethyl acetate and subsequent chromatographic separation of the fractions led to the isolation of four compounds. The diethyl ether-soluble fraction yielded tyrosol [2-(4-hydroxyphenyl)ethanol] (1); (+)-balanophonin (2), an 8-5′ neolignan, with opposite optical rotation to known (−)-balanophonin; and gmelinol (3), a known lignan. The ethyl acetate-soluble fraction afforded a new phenylethanoid glycoside to the best of our knowledge, which was identified as (−)-p-hydroxyphenylethyl[5′″-O-(3,4-dimethoxycinnamoyl)-β-d-apiofuranosyl(1′" → 6′)]-β-d-glucopyranoside (4). From the methanol extract, two known compounds, 2,6-dimethoxy-p-benzoquinone (5) and 3,4,5-trimethoxyphenol (6), were isolated and identified. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay of the identifi ed compounds indicated that 3,4,5-trimethoxyphenol (6) exhibited moderate activity. Part of this report was presented at the 57th and 58th Annual Meetings of the Japan Wood Research Society, Hiroshima and Tsukuba, August 2007 and March 2008, respectively     

Cytotoxic resveratrol oligomers from the tree bark of Dipterocarpus hasseltii

A new resveratrol tetramer, named diptoindonesin E, was isolated from the acetone extract of the tree bark of Dipterocarpus hasseltii, together with five known resveratrol oligomers (-)-epsilon-viniferin, laevifonol, (-)-alpha-viniferin, vaticanol B, (-)-hopeaphenol, and a coumarin, scopoletin. The structures of these compounds were determined from spectroscopic evidence. Cytotoxicity test of the isolated compounds showed that hopeaphenol strongly inhibited murine leukemia P-388 cells.     

Effect of four multipurpose tree species on soil amelioration during tree fallow in Central Togo

The effects of Cassia siamea, Albizia lebbek, Acacia auriculiformis, and Azadirachta indica on soil fertility have been studied on five-year-old fallows on Ferric Acrisols in Central Togo. Litter quality and soil fertility under the four species were significantly different. Topsoil pH increases significantly with increasing litter Ca levels. Cassia siamea and Azadirachta indica were superior in enriching the sandy-loamy topsoils with Calcium and in increasing soil pH. Under Acacia, which had the highest biomass production, litter accumulation appeared to be responsible for the low mineral soil Ca and P values. In addition, topsoil pH under Acacia was lower than under grass or bush fallow or the other species. Slow litter mineralization of Acacia auriculiformis was probably caused by the thick, leathery consistence and high tannin content of its litter. Due to its high biomass production supporting soil acidification pure Acacia auriculiformis stands seemed to be less favourable for improving soil fertility on planted fallows but more suited for firewood plantations and topsoil protection. The foliage as well as the litter and topsoil under Albizia showed narrow C/N- and C/P-ratios resulting in easily mineralizable organic matter. All tree species tested were superior to natural grass/herb fallow in building up surface soil fertility. However, differences with natural bush fallow were not significant.

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Résumé Au bout de cinq ans des differences fortement significative ont été trouvées quant aux caractères de la litière et de la fertilité des jachères arborées avec Cassia siamea, Albizia lebbek, Acacia auriculiformis et Azadirachta indica, respectivement. ll y a une corrélation positive entre le pH de l'horizon superficiel et la teneur en Ca dans la litière: l'enrichissement du sol sable-limoneux en Ca et le pH sont plus élevés sous Cassia siamea et Azadirachta indica que sous les autres espèces. Acacia se caractérise par la plus grande production en biomasse, donc une accumulation importante de litière sur le sol, ce qui entraîne les plus faibles teneurs en P et Ca dans l'horizon de surface. En plus, il semble qu'elle fait diminuer le pH parce que les valeurs trouvées sont inférieures à celles des parcelles témoin ou des autres espèces. La mineralisation retardée de la litière de Acacia auriculiformis depend probablement de la consistence des feuilles et du content élevé de tannine. Acacia est par consequent moins favorable à des jachères plantées mais plutôt efficace quant à la production du bois de feu et la protection du sol contre l'érosion. Vu les petits rapport C/N et C/P dans les feuilles, la litière et dans l'horizon superficiel d'Albizia, on peut supposer que sa matière organique soit plus facilement décomposable. Toutes les espèces d'arbre étudiées sont plus capables de lever la fertilité des sols que les herbes des parcelles témoin. La comparaison avec une jachère spontanée d'arbustes ne fait pas apparâitre d'effets significatifs.

     

Long-term re-use of tree roosts by European forest bats

The few studies that have assessed the long-term patterns of re-use of tree cavities by bats all concern North American bats. We studied long-term re-use of tree cavities by two species of European bat, Daubenton's bats (Myotis daubentonii) and noctules (Nyctalus noctula). Cavities were inspected during consecutive years via direct capture of bats (more than 340 positive capture events, ca 2950 captured bats), observations of emerging bats, or by listening for bats during the early evening when bats emit typical vocalization (over 160 positive checks, over 450 observed bats). Between 1968 and 2007, we found 80 tree cavities used by bats (mostly excavated by woodpeckers) in the Czech Republic. Although more than half of the cavities were occupied for ≤4 summers, 28 cavities (35%) were re-used for 5–10 years. The longest period a cavity was used was 11 and 16 years for Daubenton's and noctule bats, respectively. Sixteen tree cavities (20%) were occupied solely by Daubenton's bats and 33 cavities (41%) were occupied only by noctules. The other 31 cavities (39%) were used by both species, either at separate times or simultaneously. Our data suggest that the larger volume of a cavity, the longer duration of re-use and the greater the probability of being occupied by both species. Continuous excavation of cavities by woodpeckers prevented the overgrowth of old cavities by calluses, which keep cavities accessible to bats. We suggest that woodpeckers may be the most important providers of suitable roosts for forest bats in Central Europe. Roosts were found in both economically valuable trees (Quercus robur and Tilia cordata) and less valuable tree species (Salix fragilis and Alnus glutinuosa). Economically valuable trees in our study area were long-lived and likely provide roosting habitat for longer periods but matured at a greater age. However, less economically valuable trees reached maturity and started to decay in a relatively short time, which may provide suitable cavities at a younger age. Maintaining both types of trees within forests may help provide suitable roosting oportunities for tree-dwelling bats in the Czech Republic.     

Resistance of larches to bark stripping by sika deer in Hokkaido,northern Japan

Resistance of the Japanese larch (Larix kaempferi) (Lk), the Kurile larch (L. gmelinii var. japonica) (Lg), and their F₁ hybrid (Lg × Lk) to bark stripping by sika deer (Cervus nippon yesoensis) were studied in a forest in Hokkaido by cafeteria tests. Several sets of logs prepared from Lk, Lg, and Lg × Lk were fed to the deer. The stripped areas of logs significantly differed between the Lk/Lg set and the Lk/Lg × Lk set (P 0.05). The resistances of Lg and Lg × Lk to bark stripping was stronger than Lk. This result was similar to those of previous studies on gray-sided voles and mountain hares in Hokkaido.     

Effects of thinning on growth of six tree species in north-temperate forests of Lithuania

This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.     

Antifungal activities of compounds isolated from the leaves of Taxus cuspidata var. nana against plant pathogenic fungi

Antifungal activities of seven compounds, taxinine (1), paclitaxel (2), phenylisoserine methyl ester (3), sciadopitysin (4), ginkgetin (5), isorhamnetin (6), and quercetin (7), isolated from the leaves of kyaraboku, Taxus cuspidata var. nana, against five plant pathogenic fungi, Gibberella fujikuroi, Cladosporium cucumeninum, Fusarium oxysporum, Colletotrichum fragariae, and Corynespora cassiicola, were investigated for utilization of extractives from trees of the genus Taxus. Also, the amounts of compounds 2 and 3 on the leaf surface was measured in relation to the antifungal activities of compounds. Taxinine (1) showed antifungal activity against G. fujikuroi, C. cucumeninum, F. oxysporum, and C. cassiicola. The minimum inhibitory concentration of taxinine for the four fungi was 0.4mol. In addition, from the results of antifungal tests, it may be concluded that paclitaxel on the leaves and stem of T. cuspidata var. nana does not play an important role as an antifungicide in the resistance of trees to plant pathogenic fungal attack.     

Water and nitrogen dynamics in rotational woodlots of five tree species in western Tanzania

The objective of this study was to compare the effects of woodlots of five tree species, continuous maize (Zea mays L.) and natural fallow on soil water and nitrogen dynamics in western Tanzania. The tree species evaluated were Acacia crassicarpa (A. Cunn. ex Benth.), Acacia julifera (Berth.), Acacia leptocarpa (A. Cunn. ex Benth), Leucaena pallida (Britton and Rose), and Senna siamea (Lamarck) Irwin & Barneby). The field experiment was established in November 1996 in a completely randomized block design replicated three times. Maize was intercropped between the trees during the first three years after planting and thereafter the trees were allowed to grow as pure woodlots for another two years. Transpiration by the trees was monitored when they were 3 years old using sap flow gauges. Soil water content was measured using the neutron probe approach between November 1999 and March 2001. Soil inorganic N profiles were measured when the trees were four years old in all treatments. The results indicated that the trees transpired more water than natural fallow vegetation during the dry season. The difference was apparent at a depth of 35 cm soil, but was more pronounced in deeper horizons. The water content in the entire soil profile under woodlots and natural fallow during the dry period was 0.01 to 0.06 cm³ cm⁻³ lower than in the annual cropped plots. This pattern was reversed after rainfall, when woodlots of A. crassicarpa, A. leptocarpa, A. julifera, S. siamea and L. pallida contained greater quantity of stored water than natural fallow or continuous maize by as much as 0.00 to 0.02, 0.01 to 0.04, 0.01 to 0.04, 0.01 to 0.03 and 0.00 to 0.02 cm³ cm⁻³, respectively. Natural fallow plots contained the lowest quantity of stored water within the entire profile during this period. Transpiration was greatest in A. crassicarpa and lowest in L. pallida. All tree species examined were `scavengers' of N and retrieved inorganic N from soil horizons up to 2-m depth and increased its concentration close to their trunks. This study has provided evidence in semi-arid environments that woodlots can effectively retrieve subsoil N and store more soil water after rains than natural fallow and bare soil. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antimicrobial activity of some medicinal plants from India

The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported.     

Comparison of terpenes in extracts from the resin and the bark of the resinous stem canker of Chamaecyparis obtusa and Thujopsis dolabrata var. hondae

A monoterpene and 15 diterpenes were isolated from the ethyl acetate extracts of the bark-glued resin from the resinous stem canker ofThujopsis dolabrata var.hondae Makino. A monoterpene (nezukone20) and 4 diterpenes (acetyl torulosol5, acetyl isocupressic acid8, acetyl abietinol11, and 7-methoxytotarol18) were characteristic constituents of the ethyl acetate extracts but were absent in then-hexane extracts from the resinous stem canker ofT. dolabrata var.hondae. These terpenes were first isolated fromT. dolabrata var.hondae andT. dolabrata. The available literature suggests that diterpene18 is a new compound. The resinous stem canker ofChamaecyparis obtusa Endlicher contained larger amounts of manool1,trans-communic acid6, and ferruginol12 and smaller amounts of isocupressic acid7 and abietinol10 than the resinous stem canker ofT. dolabrata var.hondae. The concentration of18 was less than 2% in the extracts, and the resinous stem canker ofC. obtusa lacked this compound. The resinous stem cankers ofC. obtusa andT. dolabrata var.hondae provided extracts 15.6 and 4.96 times, respectively, heavier than the healthy ones. Large differences in the ratios and compositions of terpenes were also observed between the resinous stem canker and the healthy trees. Terpenes isolated from the extracts contained many kinds of diterpene, especially the labdane-type diterpenes, in these diseased trees. These results suggest that the presence of labdane-type diterpenes is closely associated with the resinous stem canker or the causal fungi of this disease.Part of this report was presented at the 50th annual meeting of the Japan Wood Research Society, Kyoto, April 2000     

Relationship between resistance to vole browsing and content of ether extract in the bark of larch species and hybrids

We determined the survival rate of tree families produced by the intra- and interspecific crossing of larch species damaged by browsing of vole (Clethrionomys rufocanus bedfordiae Thomas) and the contents of ether extracts (EE) in their bark. The average survival ofLarix gmelini var.japonica Pilg. (L. gmelini)×L. gmelini (G×G) was highest, followed by the hybridL. gmelini×L. leptolepis Gordon (G×L). The families of the hybrid G×L, which is considered suitable for silviculture in Hokkaido, Japan, showed significant differences in survival rates, suggesting that it is possible to produce improved varieties of the hybrid which are more resistant to vole browsing. The EE contents of the bark were under strong hereditary control, and the rank of the EE content among the various families hardly fluctuated between the location of the test fields. The correlation coefficient between the survival rates and the EE contents was highly significant (r=0.89,n=24,p<0.01), indicating that the EE content in the bark may be used as a possible index of resistance or susceptibility to vole browsing in larch plantations. A part of this report was presented at the 106th Annual Meeting of the Japanese Forestry Society, at Sapporo, April, 1995.     

Investigation of change in tangential strain on the inner bark of the stem and root ofBetula platyphylla var.japonica andAcer mono during sap season

Although it is well known that sap exudation during early spring in temperate deciduous trees occurs in response to daytime warming and nighttime cooling, the mechanisms of the process are not yet fully understood. Previous theories suggested that changes in stress in the wood caused by daytime heating and nighttime cooling might be linked with sap flow. Consequently, a study of itaya-kaede maple (Aver mono) and shirakamba birch (Betula platyphylla var.japonica) looked at tangential strains. One-hour intervals for 3 years of the tangential strains on the inner bark of stem and root were measured in itaya-kaede maple and shirakamba birch during the sap exudation season. The measurements indicated different mechanisms of sap exudation in these two trees. During the sap exudation season in late March, when the temperature fluctuated around 0°C, the tangential strain in the root of itaya-kaede maple showed expansion in the daytime and contraction at night. Conversely, in early April the tangential strain in the root of shirakamba birch exhibited contraction in the daytime and expansion at night. The changes in tangential strains in itaya-kaede maple were attributed to conditioning, a known concept used to explain the uptake mechanism of soil water in maple and its exudation during early spring. However, because the change in tangential strain in the roots of shirakamba birch was similar to that found during the rampant season, sap exudation was not attributed to conditioning but to the plentiful supply of water from the roots. The implications of these mechanisms are that different sap harvesting techniques may be appropriate for different tree species.     

Mitogenic effect of Carthamus lanatus extracts, fractions and constituents

Extracts, fractions and constituents of Carthamus lanatus were tested for their mitogenic effect on bone marrow cells in mice. Most of the studied samples inhibited cell proliferation and only the flavonoid glycoside rutin caused increasing of mitotic activity.     

Management of secondary tree species in agroforestry systems to improve production sustainability in Amazonian Ecuador

Three production systems (robusta coffee, cattle pastures and swidden agriculture), all associated with trees, have provided a strategy for regional development in the Ecuadorian Amazon. Feedback from more than 250 on-farm demonstrations, project evaluations and visitors have all contributed to strengthening the ability of the Ecuadorean Ministry of Agriculture's Forestry Directorate to provide colonists and indigenous groups with management guidelines for low-input sustainable agroforestry production. The existing market for 20 fastgrowing native tree species presents an opportunity for the diversification of farm income (currently dependent on robusta coffee) and for the development of a forest industrial base.The collective area of land owned and operated by these small holders constitutes a national resource and a Collective Forest Estate that can be individually managed. Commercial timber production in these extensive secondary forests can help alleviate conversion of primary forest without taking agricultural land out of production.     

The potential of some neotropical Albizia species and close relatives as fodder resources

Six neotropical woody Mimosoid legume species, in the genera Albizia, Hesperalbizia, Pseudosamanea and Samanea, were evaluated for potential as animal fodder, using a combination of analytical techniques, in vitro digestibility, and assessment of relative palatability to sheep in a preference test in Honduras. Leaf chemical composition was evaluated in terms of content of crude protein, acid detergent fibre, neutral detergent fibre, condensed tannins (acid butanol assay) and total tannins (protein precipitation: radial diffusion assay). Crude protein and digestibility data were combined into an ‘index’ by which the species could be ranked; according to this criterion the most promising species were Pseudosamanea guachapele, Albizia adinocephala and Hesperalbizia occidentalis. In the preference test, however, Pseudosamanea guachapele and Albizia niopoides appeared much more palatable to sheep than any of the other species. A small amount of H. occidentalis was also eaten, but the other species were completely refused throughout the 16 day experiment. H. occidentalis was the fastest-growing species on this site. Using a combination of these evaluation criteria, H. occidentalis and P. guachapele appear to be the species with the greatest potential for fodder use. This revised version was published online in June 2006 with corrections to the Cover Date.     

Initial growth of pioneer timber tree species in a Taungya system in the humid lowlands of Costa Rica

The temporary association of annual crops in juvenile tree plantations (Taungya system) can reduce or offset the initial costs of reforestation and hence provide incentives for tree planting on private farms. A replicated systematic spacing design, derived from a Nelder-fan design, was used to study the effects of tree-crop distance on growth and development of the timber species salmwood (Cordia alliodora) or eucalyptus (Eucalyptus deglupta), associated with maize (Zea mays) or cassava (Manihot esculenta), during the first year after transplanting the trees on two sites on alluvial soils in the humid lowlands of Costa Rica. Association with maize did not affect mean tree growth. However, mean eucalyptus and salmwood heights of 7–8 m and 3–4 m, respectively, after one year in pure plantation or associated with maize, were only 4.7 m and 1.4 m, respectively, when associated with cassava. Wider tree – crop spacings were more important for initial salmwood growth than for eucalyptus. It was concluded that the shoot growth characteristics (continuous or episodical growth) of the timber species is a very important consideration when selecting associated agricultural crop species and tree-crop distances.     

Evaluation of native tree species for the rehabilitation of deforested areas in a Mexican cloud forest

Four native tree species (Liquidambar styraciflua, Juglans pyriformis, Podocarpus matudae, and Carpinus caroliniana) were evaluated for their suitability in rehabilitating degraded areas of Mexican cloud forest. Plant survival and growth in height and diameter were determined in three mixed-experimental plantations with different land use histories; their performance was compared with two on-farm plantations started by landowners for forest restoration. Nearby forest fragments were controls for soil compaction. An experimental plantation with remnant trees had the highest plant survival (82%), height, basal diameter and relative growth rate. The plantation with the steepest slope had high plant survival (63%) and growth. The plantation characterized by dominance of grasses and compacted soils had the lowest survival (22%) and growth. On-farm plantations had good establishment of planted trees (5–10 species planted), and facilitated the recruitment of 9–11 woody species. Carpinus and Liquidambar appear to be suitable species for reforestation in all these areas. Podocarpus grew relatively slowly, although it performed well in two experimental sites. Juglans had high survival (76%) under the stressful conditions of the most adverse site, and therefore may be useful for rehabilitation of degraded sites. Differences among species and sites strongly suggest that species success depends on plantation site quality.