Comparative evaluation of successive extracts of leaf and stem bark of Albizzia lebbeck for mast cell stabilization activity

Successive chloroform, methanol and water extracts of bark and leaves of Albizzia lebbeck were tested for its in vitro mast cell stabilizing effect against compound 48/80. Methanolic extract of leaf and methanolic and water extracts of bark have shown maximum activity comparable to that of disodium chromoglycate.     

Effects of weather conditions on mast year frequency in beech (Fagus sylvatica L.) in Sweden

During the last two decades, an increase of the frequency ofnaturally regenerated beech seedlings has been reported. Thismay be due to an increased masting. In this investigation insouthern Sweden, mast year frequency, mast crop size and therelationships between mast year and climatic variables werestudied. Our analysis shows that while the average mast yearinterval was 4–6 years from the end of the seventeenthcentury up to the 1960s, the mean interval has decreased to2.5 years during the most recent 30 years, and there have beentwo consecutive mast years on two occasions during this laterperiod. Mast years have often followed years in which the temperaturein July and September was higher than the 30-year mean. However,there were significant variations in the amounts of beechnutsproduced between different mast years, and beechnut productionincreased with increasing site index. Climatic changes, especiallyincreases in temperature, may have been responsible for thehigher frequency of mast years, but increased atmospheric nitrogendeposition may also have been a contributory factor.     

A sixteen-year record of regional and temporal variation in the fruiting of beech (Fagus sylvatica L.) in England (1980-;1995)

Annual production of mast by the beech is highly variable, yetthere are few long-term records of the extent of masting whichmight help to explain the masting phenomenon. In this 16-yearstudy, beech mast has been sampled from 100 trees by 7-min samplescollected from the ground and from low-growing branches at sitesranging from the south to the north of England, and varyingfrom closed canopy beechwood to shelter belts, avenues and isolatedtrees in parks. Variation in production of viable seed is much greater fromyear to year than from north to south. Good masting occurredin 1980, 1982, 1984, 1990 and 1995: in these years at leastone year of very bad masting normally followed. Otherwise, predictionof masting is unreliable. No full mast was found in 1981. Overallthere was very little full mast in five other years, but evenin these years, some sites or some trees produced an appreciableamount. All trees produced empty pericarps as well as full mast, especiallyon lower or shaded branches. Isolated trees produced more emptypericarps than trees in groups; this is likely to result froma lack of cross pollination. It is concluded that ground samplingfor a fixed period affords a rapid and effective method of assessingmasting despite the factors intervening between mast sheddingand collection.     

Masting in Fagus crenata and its influence on the nitrogen content and dry mass of winter buds

In Fagus, full-mast seeding years are invariably followed by at least one non-mast year. Both flower and leaf primordia develop during the summer within the same winter buds. Flower bud initiation occurs when the N content of developing seeds is increasing rapidly. We hypothesized that competition for nitrogen (N) between developing seeds and buds limits flower primordium formation in mast years and, hence, limits seed production in years following mast years. We tested this hypothesis in three Fagus crenata Blume forests at elevations of 550, 900 and 1500 m. Bud N concentration (N con), amount of N per bud (N bud) and dry mass per bud (DM) were compared between a mast year (2005) and the following non-mast year (2006), and between winter buds containing both leaf and flower primoridia (BF), which were formed during the non-mast year, and winter buds containing leaf primordia only (BL), which were formed in both mast and non-mast years. In addition, leaf numbers per shoot corresponding to the analyzed buds were counted, and the effect of masting on litter production was analyzed by quantifying the amounts of litter that fell in the years 2004 to 2007. The dry mass and N content of BF formed in 2006 by trees at both 550 and 1500 m were 2.1-3.4-fold higher than the corresponding amounts in BL, although the numbers of leaves per current-year shoot in 2007 that developed from the two bud types in the same individuals did not differ significantly. These results indicate that more N and carbohydrate are expended in producing BF than in producing BL. The amount of litter from reproductive organs produced in the mast year was similar to the amount of leaf litter at 900 and 1500 m, but three times as much at 550 m. Leaf numbers per shoot were significantly lower at all elevations in the mast year than in the non-mast years (and the amount of leaf litter at 550 and 1500 m tended to be lower in the mast year than in the non-mast years. In conclusion, preferential allocation of resources to seeds in the mast year reduced the availability of resources for flower primordium formation, and this may have accounted for the poor seed production in the following non-mast year.     

Masting behaviour and dendrochronology of European beech (Fagus sylvatica L.) in southern Sweden

To identify weather controls of beech diameter growth and masting in southern Sweden, we analyze records of monthly weather, regional masting record, and tree-ring chronologies from five beech-dominated stands. The results indicate a strong weather control of temporal pattern of masting events in southern Sweden over the second half of the 20th century. Negative summer temperature anomaly 2 years prior to a mast year, coupled with positive temperature anomaly in the year immediately preceding the same mast year, is a characteristic weather pattern associated with known mast years. Strong dependence of beech masting behaviour on temperature explains the high degree of regional synchronization of masting events. Growth of beech in southern Sweden is strongly and negatively correlated with previous year's summer temperature and positively – with previous year's October temperature. The present study does not provide a conclusive answer in identifying a full set of direct and indirect effects of climatic variables controlling tree-ring growth, since the negative effect of previous year's summer temperature may be a result of a temperature-controlled increase in the beech nut production in the current year. Consistent and significant negative departures of ring-width index during mast years support the hypothesis about a trade-off between investment of bioassimilates into production of beech nuts and tree-ring growth. Alternative explanation of growth anomalies in mast years, relating such anomaly to a negative impact of previous year's growing season, was not supported by the data. We found a limited effect of masting on diameter growth in the following years, indicating that decline in the overall wood production, associated with heavy masting, is short term and typically occurs in the year of actual masting.     

Sexual reproduction contributes little to regeneration of a clonal species Corylus mandshurica

To date, the evolutionary significance of mast seeding is still poorly understood. It is also not clear whether and how seed production and clonal growth interact and then influence the colonization and recruitment of plant species that seeds are dispersed by animals. We released seeds of Corylus mandshurica in seed-rich and seed-poor years (2008–2012), to test the effects of mast seeding and clonal growth on regeneration of this clonal shrub. Our study showed that seed caching of C. mandshurica was higher in seed-rich years than that in seed-poor years. However, mast seeding failed to result in seedling establishment of C. mandshurica. Despite a negative effect of mast seeding, vegetative reproduction was common in the seven consecutive years (2007–2013), suggesting that clonal reproduction plays an important role in population spreading of C. mandshurica. Seeds are unlikely to produce seedlings in both seed-rich and poor years, suggesting that sexual reproduction contributes little to the regeneration of C. mandshurica but may be responsible for initial establishment via episodic seed dispersal.     

THE INFLUENCE OF WEATHER ON THE FREQUENCY OF BEECH MAST YEARS IN ENGLAND

Records are collected of beech masts (Fagus sylvatica L.) forthe period 1921–50 and these records are compared in atable with the temperature, rainfall, and sunshine figures ofthe 5 months, May to September, of the preceding summer. Itis shown that there are significant correlations between thesize of mast and (i) July air temperature and (ii) July sunshine.Other factors affecting mast are considered and in particularthe damaging effect of spring frosts to the flowers of beech.     

Antipruritic activity of extracts of Humulus scandens, the combinations of bioactive flavonoids

The antipruritic effects of the ethanol fractions of Humulus scandens on the 4-AP (4-aminopyridine)-induced and chloroquine-induced scratching in ICR mice were examined. The 40% ethanol fractions of H. scandens suppressed both the 4-AP- and chloroquine-induced scratching behavior, which significantly inhibited degranulation of rat peritoneal mast cell and antigen-stimulated histamine release. Further studies proved that the 40% ethanol fractions of H. scandens decreased the content of IL4 in serum of chloroquine-induced scratching ICR mice. The results suggest that the 40% ethanol fractions of H. scandens has antipruritic effects on both antihistamine-resistant and -sensitive pruritus.     

La pourriture des faines causfée par Rhizoctonia solani Kühn: Incidence de cette maladie après les fainées de 1974 et 1976. Traitement curatif des faines en vue de la conservation

Rot of beechnuts caused by Rhizoctonia solani Kühn. Disease incidence after the 1974 and 1976 mast years. Curative seed treatment before storage. Rot of beechnuts by Rhizoctonia solani Kühn, occurred throughout French beech forests after the masts of 1974 and 1976. The site conditions and the climatic conditions of November and December determine the incidence of disease which is notably reduced by soil cultivation before the mast. Thermotherapy - 24 hours at 36–38°C at 100 % relative humidity - was shown to be a curative treatment of seeds before storage.     

Climate,tree masting and spatial behaviour in wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis> L.): insight from a long-term study

Key message

Climate factors affect seed biomass production which in turn influences autumn wild boar spatial behaviour. Adaptive management strategies require an understanding of both masting and its influence on the behaviour of pulsed resource consumers like wild boar.

Context

Pulsed resources ecosystem could be strongly affected by climate. Disantangling the role of climate on mast seeding allow to understand a seed consumer spatial behaviour to design proper wildlife and forest management strategies.

Aims

We investigated the relationship between mast seeding and climatic variables and we evaluated the influence of mast seeding on wild boar home range dynamics.

Methods

We analysed mast seeding as seed biomass production of three broadleaf tree species (Fagus sylvatica L., Quercus cerris L., Castanea sativa Mill.) in the northern Apennines. Next, we explored which climatic variables affected tree masting patterns and finally we tested the effect of both climate and seed biomass production on wild boar home range size.

Results

Seed biomass production is partially regulated by climate; high precipitation in spring of the current year positively affects seed biomass production while summer precipitation of previous year has an opposite effect. Wild boar home range size is negatively correlated to seed biomass production, and the climate only partially contributes to determine wild boar spatial behaviour.

Conclusion

Climate factors influence mast seeding, and the negative correlation between wild boar home range and mast seeding should be taken into account for designing integrated, proactive hunting management.

     

Suggestions for 'Automatic Forest Fertilisation' by a Wind-Operated System

A system is suggested whereby a large area may be automaticallyfertilised by regular small applications. There is also thepossibility of distributing insecticides or fungicides at minimalcost. The system consists of a high steel mast, a rotary atomiser,a wind driven generator, storage tanks and various control devices.     

桩基础工程施工质量事故处理探讨

基础工程是建筑物根基,应保证每一环节不能出现偏差。地质勘察要准确;设计必须符合国 家设计规范要求;施工必须按国家施工规范要求施。无论在哪一环节上出现失误,都将会造成重大的质量事 故,后果不勘设想。因此要求每一环节必须严把质量关,才能确保工程质量。     

ERRATUM

THE author has called our attention to a mistake in her paper‘Squirrel Populations and their Control’ publishedin the recent Supplement to Forestry ‘Wildlife in theForest’. The mistake occurs in the second paragraph ofpage 19 where the fall in the estimated population of grey squirrelsfollowing a mast failure should be 468 to 66 and not 468 to466.     

Annual and geographic variation in seed traits of Argentinean populations of southern beech Nothofagus nervosa (Phil.) Dim. et Mil.

Nothofagus nervosa (=N. alpina) is one of the most important native forest tree species of Argentina, with a very small natural distribution area, fast growth and a high wood quality. Its overexploitation in the past seriously affected some populations and made others disappear, making it necessary to implement conservation policies and breeding programs.In order to study the genetic and geographic variation of the species, seeds from a total of 29 populations from the entire natural distribution area in Argentina were harvested, 11 of them during four consecutive years. Annual and geographic covariation of seed production, seed weight and proportion of seeds damaged by insects were analyzed.Significant differences among populations and among years for all studied traits were found. Seed production was highly variable, both among populations and among years. `Partial mast years' seem to occur every two years, whereas the occurrence of `full mast years' has a lower frequency. A significant population × year interaction was found both for the proportion of damaged seeds and for the seed weight. The proportion of seeds damaged by insects was very important, reaching >80% of the total seed produced in some populations. The differences in the quantity of attacked seeds among years are discussed in relation to seed production, insect's life cycle and climatic factors. Seed weight was also variable among populations and years, despite the small natural distribution area of the species in Argentina. Best seed quality, according to lower proportion of damaged seeds and higher seed weight, was observed in the analyzed `full mast year'. This would also imply a better genetic representation of populations with seed samples harvested during these years. A lower proportion of damaged seeds as well as the heaviest seeds were also found among those seeds fallen during the first part of the seed-fall period.The found covariation is discussed in relation to patterns of genetic variation previously found in this species and to the implementation of genetic studies and conservation and breeding programs.     

Anti-anaphylactic effect of Euphorbia hirta

The Euphorbia hirta ethanolic extract (EH A001) was found to possess a prominent anti-anaphylactic activity. A preventive effect of EH-A001 given by oral route at dose from 100 to 1000 mg/kg was observed against compound 48/80-induced systemic anaphylaxis. At the same range of dose, EH-A001 inhibited passive cutaneous anaphylaxis (PCA) in rat and active paw anaphylaxis in mice. A suppressive effect of EH-A001 was observed on the release of TNF-alpha and IL-6 from anti-DNP-HSA activated rat peritoneal mast cells.     

Comparative mast seed production in unmanaged and shelterwood white pine (Pinus strobus L.) stands in central Ontario

The effect of the seed cut of the uniform shelterwood silvicultural system on white pine seed production, seed characteristics, and seed viability during 2 mast seeding events was examined in operationally harvested second growth, white pine-dominated forest stands in central Ontario. Seed traps placed along transects in unmanaged and shelterwood stands in each of 3 blocks were used to monitor seed production in 2000 and 2006 (4 and 10 years after harvesting). During these 2 mast seed years between 386,000 and 2,730,600 seed ha^?1 were produced among study stands. Total seed production expressed on a per hectare and unit pine basal area basis did not differ by harvest treatment or among blocks in either year. Variability in seed production among stands was primarily due to differences in stand structure, with seed production positively related to white pine basal area. Seed characteristics were largely similar between harvested and unmanaged stands and between seed years. Seed viability was relatively high in both years, with seed from shelterwoods germinating slightly slower than those from unmanaged stands. Seed quality, as estimated by laboratory germination performance, was higher in 2006 than 2000, likely due to improved seed development and maturation in the warmer, wetter growing season of 2006. Our results suggest that the seed cut of the uniform shelterwood system applied to second growth white pine stands is unlikely to adversely affect white pine seed production, seed quality, or potential for natural regeneration during mast seeding events.     

Seed rain,soil seed bank,seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0–2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance.     

居住区儿童活动场所景观设计

通过实地调查分析发现一些居住区儿童活动场所设计时出现的问题。通过对儿童身体发育和心理发育特点的分析，给出儿童活动场所的设计原则，提出儿童活动场所景观规划设计方法，解决儿童在户外活动时面临的各种问题，旨在创造一个培养儿童创造力和好奇心、有益于儿童身心健康的居住区儿童活动空间。得出好的环境对儿童的成长起到积极的作用、居住区儿童活动场所是居住区整体环境的重要组成部分之一的结论，应该给予足够的重视。     

Effects of acorn attack by curculio weevils on the germination and early growth of <Emphasis Type="Italic">Pasania edulis</Emphasis> (Makino) seedlings

We conducted field studies to evaluate the impact that curculio weevil attacks on Pasania edulis (Fagacea) acorns have on the regeneration of this tree. The germination ratio of weevil-attacked acorns was significantly lower than that of sound acorns. The number and position of the attacks on acorns affected the germination ratio. The seedlings from weevil-attacked acorns were shorter and had a smaller leaf area than those from sound acorns. The negative effects on seedling height lasted for at least three years after germination. We also studied the handling of the two types of acorns by granivorous Apodemus mice in a broad-leaved forest dominated by P. edulis. The mice picked up, transported, hoarded, and recovered sound and weevil-attacked acorns similarly. In the study site, the seedlings from weevil-attacked acorns were estimated to account for 1.5–20.4 % of the total seedlings for cohorts of mast years and 0–3.7 % for those of poor or medium acorn production. From these results, we conclude that acorns with the lower part of their cotyledons slightly damaged by weevil larvae might still be able to contribute to the regeneration of P. edulis in the field but that their contribution would be negligible or small even in mast years in this study site.     

Gene flow pattern and mating system in a small population of Quercus semiserrata Roxb. (Fagaceae)

Pollen flow from external sources is important for the conservation of tree species in fragmented forests or small populations, because it can be sufficient to prevent differentiation among them, and appears to be able to prevent the loss of their genetic diversity through genetic drift. In this study, we examined the genetic heterogeneity of pollen pools accepted by each Quercus semiserrata seed parent at the Khun Wang Royal Agriculture Research Center, Thailand, both within and among two mast fruiting years (2005 and 2007), using paternity analysis and analysis of molecular variance (AMOVA). The mating systems of the trees were also examined using the multilocus mating system model (MLTR), after determining the genotypes at eight microsatellite loci of 26 seed-trees and 435 seeds from 8 seed-trees in the 2 mast fruiting years. The average distance of effective pollen flow within the plot was estimated to be 52.4 m, and 95% of effective pollen was dispersed within 200 m, indicating that effective pollen flow is highly localized and that most effective pollen is contributed by near-neighbor trees. The proportion of effective pollen that immigrated from external sources was estimated to be 26.2%. The AMOVA analysis based on the pollen haplotypes showed that the pollen pools, both total and for each reproductive year, significantly genetically differed among the seed parents. Using a mixed mating model, the estimate of biparental inbreeding for the total population (t_m − t_s) was 0.013, indicating that a low proportion of mating occurred among close relatives. The effective number of pollen donors (N_ep) was estimated to be 9.987 using the TwoGener model, or 10.989 using the mixed mating model. The effective number of pollen donors of seeds was higher in the mast fruiting year 2005 than in the other examined year, 2007. Consequently the allelic richness and genetic diversity of seeds produced in 2005 were higher than those produced in 2007. Overall, the results show that high outcrossing rates, high levels of gene flow from other populations and heterogeneity in the pollen received by an individual may enhance the ability of populations to maintain effective population sizes. Therefore, these processes may be sufficient to prevent loss of genetic diversity through genetic drift of Q. semiserrata at this study site.