Showing papers by "Forest Research Institute published in 1985"

General flowering in the climax rain forests of South-east Asia

Abstract: The general flowering of lowland dipterocarp forests of South-east Asia is a unique phenomenon that occurs intermittently, sometimes many years apart, and may be widespread throughout the region or sporadic. During a general flowering a very large number of tree families, including the well-known Dipterocarpaceae, flower and fruit exceptionally heavily. The huge pulse of flowering is echoed by an apparent explosion in the number of pollinators, and this is further augmented by migration of pollinators from the forest fringes. The huge demand for pollinators seems to be solved among several dipterocarps through utilization of tiny, fast breeding, floral-feeding insects such as thrips and hoppers. Competition for pollinators is further reduced through development of sequential flowering among several groups of trees that share similar pollinators. The resulting massive general fruiting seems to contribute to a heightened level of faunal activity and numbers. This long-intervalled flowering and fruiting phenology which dominates these lowland dipterocarp forests may have partly contributed to the lowered animal biomass frequently alluded to when these forests are compared with neotropical forests.

Effect of Sulphur Dioxide and Sulphuric Acid on Steam Explosion of Aspenwood

Abstract: The use of steam explosion as a pretreatment for woody biomass prior to enzymatic hydrolysis has been proposed in the past. In this study the effect of SO2 impregnation (1.6% SO2 on dry wood input) and H2SO4 impregnation (0.58% H2SO4 on dry wood input) on the exploded substrates produced are compared with the case where no acid was added. Both acid catalysts substantially improve the survival of pentose sugars when treatments of equal severity are compared. H2SO4 however reduces the extent to which lignin may be extracted from the water washed exploded substrates with caustic. The mode of action of the SO2 has been examined and, at the levels used in this work, approximately 50% of the input sulphur is shown to bind to the substrate forming, most likely, ligno-sulphonates. The enzymic digestibilities of the acid impregnated steam exploded substrates are compared with those of the non-acid impregnated material and are shown to be more easily saccharified.

Ceratocysts polonica inoculated in Norway spruce: Blue‐staining in relation to inoculum density, resinosis and tree growth

Abstract: When Norway spruce trees were inoculated with Ceratocystis polonica, a dose-dependent response was recorded. Local resinosis near the inoculation sites decreased with increasing inoculum density; parallelled by an increasing degree of sapwood staining, and tree mortality. Suppressed trees, and trees showing growth decline appeared more susceptible than trees suffering less competition.

Landsliding during a M 7.7 earthquake: Influence of geology and topography

Abstract: The 1929 M 7.7 Murchison earthquake in northwestern South Island, New Zealand, triggered at least 1850 landslides larger than 0.25 ha within a 1200-km 2 (45 × 25 km) area close to the epicenter. The area surveyed in detail totals 25% of the area in which the earthquake initiated landslides. About 2.5 × 10 8 m 3 of debris was transported by landslides in the area surveyed, equivalent to an average debris yield of 210 000 m 3 /km 2 . Landsliding was most common on well-bedded and jointed, calcareous, Tertiary mudstones and fine sandstones and was particularly concentrated on scarp slopes in areas of both gentle and moderate to steep dip. On moderately to steeply dipping mudstones, scarp slopes facing away from the origin of the seismic waves were particularly prone to landsliding. Large dip-slope landslides were common on thick-bedded Tertiary sandstones. Landslides on granitic rocks were generally smaller, shallower, and composed of finer grained debris than those of sedimentary rocks.

The Starches of Dioscorea ballophylla and Amorphophallus campanulatus. Comparison with Tapioca Starch

Abstract: Starches from the tubers of Dioscorea ballophylla and Amorphophallus campanulatus were isolated and purified. Scanning electron microscopy of these starches exhibits eliptical, spherical or irregular shapes, respectively, while the shape of tapioca is spherical. Water-binding capacity of A. campanulatus starch is very high in comparison to D. ballophylla and tapioca starches but the amylose content is significantly less. Gelatinization temperature of both these starches is the same but it is higher when compared to tapioca starch, swelling power and solubilities are less. Paste viscosity characteristics show high peak viscosity for A. campanulatus in comparison to D. ballophylla and tapioca starch. Die Starken von Dioscorea ballophylla und Amorphophallus campanulatus. Vergleich mit Tapiokastarke. Die Starken der Knollen von Dioscorea ballophylla und Amorphophallus campanulatus wurden isoliert und gereinigt. Die Raster-Elektronenmikroskopie dieser Starken zeigt elliptische, spharische oder unregelmasige Formen, wahrend die Form von Tapiokastarke spharisch ist. Das Wasserbindungsvermogen der Starke von A. campanulatus ist sehr hoch im Vergleich zu den Starken von D. ballophylla und Tapioka, doch ist der Amylosegehalt deutlich geringer. Die Verkleisterungstemperatur der beiden Starken ist gleich, jedoch hoher im Vergleich zu Tapiokastarke; Quellvermogen und Loslichkeiten sind geringer. Der Viskositatsverlauf zeigt hohere Spitzenviskositat bei A. campanulatus im Vergleich zu D. ballophylla und Tapiokastarke.

A distribution map for Seiridium cardinale causing the cypress canker disease in Greece

Abstract: The first distribution map of Seiridium (Coryneum) cardinale (Wag.) Sutton and Gibson which causes the cypress canker in Greece is given. A recent survey all over the country has shown that S. W. Greece and the Ionian islands are already under heavy attack whereas in central and N. Greece and the island of Krete only restricted spots have been found. Strict sanitation measures are imposed to prevent building up and diffusion of the disease.

Weathering of quartz grains in the liquefied horizon of permafrost solonchaks in the arid steppe zone, Central Mongolia

Abstract: Morphoscopic investigations of quartz grains (0,6–0,8 mm) were carried out with the use of scanning electron microscope. The grains originated from the liquefied horizon of the strongly alkaline permafrost solonchaks of the arid steppe zone of Central Mongolia. The grain surface in this horizon is smoothed due to various processes of chemical corrosion and by deposition of silicate crusts of variable thickness. The record of the preceding abrasion resulting from transportation of weathered material to their deposition site was blurred by the above mentioned processes. The permanently hydrated cool environment favoured moreover the cryohydrothermal block- and granular disintegration as well as the cryothermal and cryomechanical fracture and chipping.

Indentation of wood by wedges

Abstract: The deformation processes involved in wedge indentation of wood are described. The behaviour of wood is compared to that of an elastic-plastic solid and that of a cellular body. It approximates towards the former when its density is high and towards the latter when its density is low. The hardness of wood is examined as a function of density and of wedge angle.

Pore width in Heterobasidion annosum (Fries) Brefeld

Abstract: Pores in 45 basidiomata of Heterobasidion annosum from New Zealand (26) and Australia (19) were significantly larger (P < 0.01) than those in 31 fructifications from North America (including 30 from British Co.lumbia) and 49 fructifications from Europe (includmg 44 from Finland). The mean distance along lines of 10 contiguous pores was 4.7 mm (range 3.7–5.8 mm) for New Zealand collections; 4.9 mm (3.8–5.9 mm) for Australian collections; 2.5 mm (1.7–3.3 mm) for collections from North America; and 2.4 mm (2.1–2.8 mm) and 3.1 mm (2.6–3.6 mm) for collections belonging to two intersterility groups (“S” and “P”) from Europe. The fungus in Australasia is therefore taxonomically distinct from forms of H. annosum present in the Northern Hemisphere.

Induced flocculation of Pachysolen tannophilus using the tower fermentor

Abstract: This article reports the induction of flocculation with Pachysolen tannophilus by the use of controlled aeration in a tower fermentor. The observed environmental and physiological conditions for flocculent growth are described. Although most studies with P. tannophilus have used oxylose as substrate, a synthetic glucose medium was chosen for this study as the faster growth rate of the organism on glucose was considered to favor more rapid selection of a flocculent strain. Due to flocculation, the concentration of yeast cells retained in the tower was up to 16 times greater than in the overflow. Ethanol yields approaching theoretical were achieved at low specific oxygen uptake rates, conditions which also favored maximum flocculation. Future work will involve continuous tower fermentation of sugar mixtures representative of the composition of wood hydrolysates.

Ants collected in pine forests infested by the pine needle gall midge in korea (hymenoptera, formicidae)

Abstract: Twenty-two species of ants are collected from red and black pine forests infested by the pine needle gall midge, Thecodiplosis japonensis, in Korea. Some of these ants are expected to be predators of the latter.

Variation in germination characteristics of some seed origins ofPinus wallichiana A B Jacks from the western Himalaya

Abstract: Seeds of kail collected from 10 localities in the western Himalaya were germinated at 4 temperatures viz 20°, 28°, 34° and 40°C after storage in dry cold conditions in freezer. The seed lots representing different localities differed in the capacity and rate of germination. At lower temperature of incubation (20°C) most of the seed lots exhibited varying degree of dormancy. This dormancy could be revoked by chilling imbibed seeds for 2 weeks at 3–5°C. At higher temperatures of incubation the seed lots did not exhibit dormancy, although the optimum conditions for germination were provided by a combination of prechilling and higher temperatures of incubation (28° and 34°C). Treatments such as prolonging the stratification period up to 38 days, soaking in GA 100 mg/litre, with or without prechilling, and in 1% H2O2, did not have any significant effect on germination. The study revealed seed source variation in the degree of dormancy at low temperature of incubation.

Yearly and Seasonal Variations in Extractable Soil Sulphate at Two Locations in Norway

Abstract: The yearly and seasonal variations in water-soluble and phosphate-extractable SO2- 4 in the soil at two locations in Norway were measured during the years 1979–1981. Two small plots at each location were sampled. The variation in the SO2- 4 fractions between the plots was explained by the differences in soil properties. The correlation coefficients between water-soluble SO2- 4 and total S were not high, but significant. Both depletion and accumulation of soluble SO2- 4 during the period of investigation were measured. Amounts of precipitation could only partly explain the observed changes. No differences between the locations could be attributed directly to the higher input of anthropogenic sulphur to one of the locations.

Status of biological control of forest insect pests in china

Abstract: The present paper reviews the recent advances of biological control of forest insect pests in China The main biological agents used for the control of forest insect pests in China are Trichogramma dendrolimi, Scleroderma gua-ni, Polyrhachis dives, Harmonia axyridis, Dendrocopes major, Beauveria bassia-na, Bacillus thuringiensis and the cytoplasmic polyhedrosis virus of Dendroli-mus punctatus, and Apocheima cinerariusTrichogramma dendrolimi has been used on a large scale in controlling forest insect pests The main target insect is the Masson pine caterpillar, Den drolimus punctatus Eggs of Antheraea pernyi, Coreyra cephalonica, and Philos-amia cynthis ricina are used as host eggs for mass production of Tdendrolimi Studies on the production of Trichogramma on artificial eggs have been carried out for several years with promising resultsScleroderma guani is the main larval parasitic of the small poplar borer, Saperda populnea, and the China fir long-horned beetle, Semannotus bifascia-tus sinoauster Field release of the wasps against the long-horned beetle resul -ted in 755% parasitism of the larvae Larvae of S populnea, S bifasiarus sinoauster and Ostrinia furnacalis may be used as hosts to rear this waspBeauveria bassiana is mainly used in controlling overwintering larvae and the first generation larvae of the pine caterpillar It is largely used in Fu-jian, Guangdong, Hunan Provinces as well as in Gangxi Zhuang Autonomous Region both as dust and ULV spray Viruses have been isolated from 61 forest insect species in China In field test, a spray suspension of CPV of Den-drolimus spectabilis was applied at a concentration of 1 × 107 PIB/ml against D punctatus, resulting in a mortality of 75% In one test, aerial spray of this virus suspension against D punctatus, covering an area of 13333ha, reached 51-71% mortality