Showing papers by "Forest Research Institute published in 1981"
TL;DR: In this article, the Coulomb strength theory was used to estimate the pore pressure in the interstitial fluid of coarse particles suspended in a slurry of coarse sand and clay.
Abstract: Within zones of little or no deformation by internal shearing in debris flows at Mt Thomas, about two-thirds of the weight of large particles is supported by buoyancy and about one-third by static grain to-grain contact. In boundary shear zones of low velocity flows and in high velocity, turbulent debris flow, grain-to grain contact is replaced by turbulence and dispersive pressure. Cohesive strength of the clay + silt + water interstitial fluid provides less than 2 % of the force keeping particles larger than 1 cm gravel in suspension.
Excess pore pressure is generated in the interstitial fluid by the weight of coarse particles suspended in the slurry. According to Coulomb strength theory, pore pressures measured in these debris-flow slurries reduce the shear strength of the material to less than 10 % of what it is in the unsaturated state. The excess pore pressures are slow to dissipate because of the small connections between pore spaces that result from the extremely poor sorting of the debris and the presence of silt and clay in the pore fluid. Maintenance of sufficient pore space to trap fluid and facilitate flow on low-gradient slopes may be accomplished by dilatancy and subsequent partial liquefaction of the debris during shear.
184 citations
TL;DR: Cluster analysis of data describing the flood hydrology of selected New Zealand catchments is used in an attempt to identify regions in which catchments have similar hydrologic regime.
156 citations
TL;DR: The behavior and form of sediment transport through a 3.5 m wide forest stream have been monitored for nearly three years as discussed by the authors, and sediment transport is highly episodic and spatially variable, and is controlled less by water discharge than by sediment availability.
Abstract: The behaviour and form of, and bedload sediment transport through, a 3.5 m wide forest stream have been monitored for nearly three years. Bedload transport is highly episodic and spatially variable, and is controlled less by water discharge than by sediment availability. Organic debris in the channel creates temporary base levels and sites at which coarse sediment may remain stored for long periods; collapse or disruption of log and debris jams makes sediment available for transport in only a small proportion of the runoff events that are actually competent to move the material. Even then, sediment travels only a short distance before being redeposited, frequently behind debris accumulations further downstream. Rates of sediment transport during a given runoff event can vary markedly over short distances along the stream, again depending on whether sediment was made available for transport by log jam collapse upstream. Organic debris is therefore a major constraint on the application of physical laws and theories to explaining sediment movement in, and the morphology of, this stream.
131 citations
TL;DR: In this article, the authors describe the morphologic, hydrologic and sedimentologic characteristics of 72 South Island, New Zealand, rivers were collected and analyzed, and the level of explanation varied for different morphologic variables; nearly 90% of the variability in cross-sectional area could be explained, but aspect ratio (maximum depth divided by hydraulic radius) was completely independent.
Abstract: Data to describe the morphologic, hydrologic and sedimentologic characteristics of 72 South Island, New Zealand, rivers were collected and analysed. Nearly 70 per cent of variation in channel morphology is accounted for by differences in cross-sectional area, slope, and cross-section shape; only 53 per cent of the morphologic variability could be statistically ‘explained’ by the hydrologic and sediment variables used. The level of explanation varied for different morphologic variables; nearly 90 per cent of the variability in cross-sectional area could be explained, but aspect ratio (maximum depth divided by hydraulic radius) was completely independent. Apart from the inadequacy of the measured variables as indices of the true underlying controlling factors, and the imperfect measurement and sampling procedures, the low level of explanation is probably due to the influence of factors such as floodplain vegetation, high quasi-random variability in bark sediment character, boundary effects imposed by bedrock bluffs, and the precise sequence of flood events, none of which are easily quantified. In addition, observations indicate that there is a large random variation in channel form which cannot be related to any factor.
An attempt to relate channel morphology to flow variability, using simple indices of the latter, was unsuccessful.
87 citations
TL;DR: Methylbutenol alone, the specific pheromone component of Ips typographus, elicited no response, but synergestic effects appeared when methyl butenol was combined withcis-verbenol and ipsdienol.
Abstract: Thanasimus formicarius (L.) responds to racemic ipsdienol and ipsenol and less to (S)-cis-verbenol. All three are pheromone components in several bark beetles of the genusIps. Synergistic effects appeared when the components were combined. Methylbutenol alone, the specific pheromone component ofIps typographus, elicited no response, but synergestic effects appeared when methylbutenol was combined withcis-verbenol and ipsdienol. The sympatric speciesThanasimus femoralis (Zett.) responds to (S)-cis-verbenol, while ipsdienol and ipsenol synergize the response.
87 citations
TL;DR: The transfer of shoots from a SH medium to a Gresshoff and Doy medium was found to be an important pretreatment which increased the survival of the shoots when they were placed in a peat and pumice mix for root formation.
Abstract: A method has been devised for the reliable production of plantlets from embryos and seedling shoot tips of Pinus radiata D.Don (radiata pine). Buds were induced on an agar or liquid Schenk and Hildebrandt (SH) medium containing 5.0 mg/l benzylaminopurine (BAP). Except for some abnormal buds, the buds grew into elongated shoots on an agar SH medium without cytokinin. The transfer of shoots from a SH medium to a Gresshoff and Doy (GD) medium was found to be an important pretreatment which increased the survival of the shoots when they were placed in a peat and pumice mix for root formation. Elongated shoots were induced to form roots under non-sterile conditions in a humid environment with occasional misting. An intervening 5-day treatment of shoots in an agar medium containing 2.0 mg/l indolebutyric acid (IBA) and 0.5 mg/l napthaleneacetic acid (NAA) significantly increased the percentage of shoots forming roots and the number of roots formed per shoot over control shoots placed directly in the peat:pumice mix. An enhanced level of CO2 during root formation had no effect on the time of root formation or on the percentage of shoots forming roots. These results concerning the elongation, growth and rooting of adventitious shoots are now being applied to the development of very large numbers of plantlets starting from cotyledons from partially germinated seeds.
78 citations
TL;DR: Length of growing season and time requirement for foliar development appear to be a principle factor in the carbon balance of deciduous species and a higher water use efficiency was found for similar atmospheric conditions in spring than in autumn.
Abstract: CO2-assimilation and leaf conductance of Larix decidua Mill. were measured in the field at high (Patscherkofel, Austria) and low (Bayreuth, Germany) elevation in Europe, and outside its natural range along an altitudinal gradient in New Zealand.
67 citations
TL;DR: Suillus lakei appears to be a common mycorrhizal fungus of Douglas fir in the South Island of New Zealand, whereas this association is rare in the North Island.
Abstract: Attempts were made to isolate mycorrhizal fungi of a timber species, Pseudotsuga menziesii (Mirb.) Franco which is exotic to New ZeaLond. Over 2000 pieces of mycorrhizal roots were plated out on Hagem medium and modified Melin-Norkrans medium; 14% of these yielded Rhizopogon vinicolor A. H. Smith, 6% gave rise to Amanita muscaria (L. ex Fr.) S.F. Gray, and 7% to unidentified basidiomycetes, 21% yielded dark sterile mycelia, 13% were sporing Fungi Imperfecti presumed to be contaminants, and 39% remained free of fungal growth. Eleven basidomycetous fungi were tested for their mycorrhiza-forming ability on P. menziesii seedlings. Under the test conditions R. vinicolor, Hebeloma crustuliniforme (Bull, ex St. Am) Quel., A. muscaria, Scleroderma bovista Fr., Laccaria laccata (Scop, ex Fr.) Berk. & Br., Inocybe corydalina (?), I. jurana (?), and I. maculata (?) formed mycorrhizas.
67 citations
TL;DR: Of the species studied, Lupinus polyphyllus was the only one capable of reasonable growth where no P was added to the soil and its greater seed reserves appeared to contribute substantially to its greater growth and P uptake under conditions of low P input.
Abstract: The phosphate response patterns of tropical and temperate legumes were compared in a glasshouse trial on a high country yellow-brown earth subsoil Differences in growth and P response patterns could be explained by the known differences in tolerance of Al toxicity The temperate legumes Lotus pedunculatus and Lupinus polyphyllus appeared to be able to tolerate Al toxicity as well as the torpicallegume Lotononis bainsu and more so than Trifolium semipilosum However Trifolium repens was less tolerant than T semipilosum Of the species studied, Lupinus polyphyllus was the only one capable of reasonable growth where no P was added to the soil The greater seed reserves of Lupinus appeared to contribute substantially to its greater growth and P uptake under conditions of low P input
40 citations
TL;DR: Ascocoryne spp.
Abstract: Ascocoryne spp. occurred only in heartwood, Neobulgaria premnophila also in sapwood, both with an upward, decreasing frequency in the lower 2–5 m of the stems. Nectria fuckeliana occurred at all heights, most abundantly in the 2–5 m above stump level and only in heartwood. Several other fungi also occurred, but less frequently.
31 citations
TL;DR: By exposing Pinus radiata seedlings to Dothistroma pini infection in the field over a period of 3 years, the main infection period in the central North Island of New Zealand was found to be from November to February (late spring to late summer).
Abstract: By exposing Pinus radiata seedlings to Dothistroma pini infection in the field over a period of 3 years, the main infection period in the central North Island of New Zealand was found to be from November to February (late spring to late summer). No infection was obtained when the air temperature was below 7°C or when the leaf wetness period was less than 10 hours.
TL;DR: The defense secretion of the nasute termiteBulbitermes singaporensis consists of 1 new and 2 known tetracyclic diterpenes that supports the kinship of the oriental ‘constricted-head’ genera withNasutitermes species in the Philippines and in East Africa.
Abstract: The defense secretion of the nasute termiteBulbitermes singaporensis consists of 1 new and 2 known tetracyclic diterpenes, spectrometrically identified as 14α-acetoxy-6,8-kempadien-3-one, 3α, 14α- and 3β, 14α-diacetoxy-6,8-kempadiene. The presence of these compounds supports the kinship of the oriental ‘constricted-head’ genera withNasutitermes species in the Philippines and in East Africa.
TL;DR: Alnus species seem to be poorer hosts for M. betulinum than the Betula species, andMelampsoridium collections on Alnus spp.
Abstract: Melampsoridium betulinum from Betula verrucosa was found able in infection experiments to infect Alnus barbata, A. cordata, A. glutinosa, A. incana, A. orientalis, A. rhombifola, and A. viridis. Melampsoridium collections on Alnus spp. in Norway, Finland, Scotland, and Ireland were identified with M. betulinum. Alnus species seem to be poorer hosts for M. betulinum than the Betula species. M. alni is conspecific with M. betulinum.
TL;DR: It is suggested that competitive mate searching has no effect on the occurrence of protandry in the pine looper Bupalus piniarius and mass trapping of males with pheromone traps does not decrease the percentage of females that mate.
Abstract: A simulation model is presented which explains the occurrence of protandry (i.e. males emerge on average before females) in the pine looper Bupalus piniarius. The model calculates the fitness of the moths in relation to their date of emergence during the period of emergence. It is investigated how this fitness is affected by: a) the difference between the mean time of emergence of males and females, b) the age of the moths at copulation, c) the mortality rate and longevity of the moths, d) the flight activity of the males, and e) the density of the moths. The input of the model is based on field data and experimental results. The model shows that a) the difference and the mean time of emergence between males and females is maintained by selection of males, such that they on average emerge 2 days before the females, b) 95% of the females mate on the day of emergence, c) the flight activity of the males together with moth density has a significant effect on the difference in time of emergence between the sexes, d) age-dependent copulation success, mortality rate and longevity do not affect the difference in time of emergence between the sexes. From the results it is concluded that mass trapping of males with pheromone traps does not decrease the percentage of females that mate. It is suggested that competitive mate searching has no effect on the occurrence of protandry.
01 Jan 1981
TL;DR: The bark beetles have become a real threat to spruce trees in south-east Norway and west-central Sweden and several factors have caused this situation.
Abstract: The spruce bark beetle, Ips typographus (L.), is one of the most serious pests for Eurasain spruce. Norway spruce, Picea abies (L.) Karst, is the usual host tree. Under normal conditions, the beetles breed in the subcortical tissue of very weak trees or trees broken or overthrown by wind. Thus, such breeding accelerates the natural decay of such trees. Healthy trees are killed only when the beetle population is high and many beetles attack simultaneously. During the last 10 years there has been a rapid growth in the population of I. typographus in Scandinavia. The bark beetles have become a real threat to spruce trees in south-east Norway and west-central Sweden. Several factors have caused this situation to occur. Since 1969 rainfall has been lower than average over large areas of Scandinavia.
01 Jan 1981
TL;DR: The Grasslands are a major vegetation type in Greece and their area is estimated to 1.7 million hectares and it represents about 13% of the total land of the country.
Abstract: Grasslands are a major vegetation type in Greece. Their area is estimated to 1.7 million hectares and it represents about 13% of the total land of the country. Almost half of them are found in northern Greece (Macedonia and Thrace)(Ministry of Agriculture, 1961), where they occupy a variety of environments from sea level up to the subalpine and the alpine zones of the high mountains.
TL;DR: Of the species studied, Lupinus polyphyllus was the only one capable of reasonable growth where no P was added to the soil, and its greater seed reserves appeared to contribute substantially to its greater growth and P uptake under conditions of low P input.
Abstract: The phosphate response patterns of tropical and temperate legumes were compared in a glasshouse trial on a high country yellow-brown earth subsoil. Differences in growth and P response patterns could be explained by the known differences in tolerance of Al toxicity. The temperate legumes Lotus pedunculatus and Lupinus polyphyllus appeared to be able to tolerate Al toxicity as well as the torpicallegume Lotononis bainsu and more so than Trifolium semipilosum. However Trifolium repens was less tolerant than T. semipilosum. Of the species studied, Lupinus polyphyllus was the only one capable of reasonable growth where no P was added to the soil. The greater seed reserves of Lupinus appeared to contribute substantially to its greater growth and P uptake under conditions of low P input.
TL;DR: In this paper, Manganese Toxicity in Growing Plants in Bark Compost is discussed, in particular when growing plants in BCHs, and the authors propose a method to mitigate the toxicity.
Abstract: (1981). Manganese Toxicity—In Particular When Growing Plants in Bark Compost. Acta Agriculturae Scandinavica: Vol. 31, No. 1, pp. 29-39.
01 Mar 1981
TL;DR: The detailed structure of the nest is described and data on distribution and swarming behaviour of the species have been incorporated.
Abstract: The paper discusses the taxonomic status ofOdontotermes distans Holmgren et Holmgren. The detailed structure of the nest is described and data on distribution and swarming behaviour of the species have been incorporated.
TL;DR: At the southern end of Rotorua airport, a depth of 45-60 cm of Typha peat overlies the Rotomahana Mud deposited in 1886.
Abstract: At the southern end of Rotorua airport a depth of 45–60 cm of Typha peat overlies the Rotomahana Mud deposited in 1886. The rate of accumulation (0.4–0.6 em per year) is rapid by world standards.
TL;DR: In this article, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis (PCA) based on monthly means of climatic variables during the period 1937-65, and the difference between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out.
Abstract: Based on monthly means of climatic variables during the period 1937–65, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis The new variables were interpreted as pairs of alternating weather types, or airmasses Four airmasses were identified, covering 20–30% of the transported air at each station The significance, properties and amounts of air transported by each airmass was calculated and distributed according to wind direction Differences between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out One of the major differences is the tendency to form high pressure over inland areas in winter vs low pressure in the summer season
01 Dec 1981
TL;DR: The Jubilee A.N.Z.A.S. Conference as mentioned in this paper has brought about an increased awareness among sociologists that we have played only a very minor role in influencing social policy.
Abstract: * This article is based on a Paper presented to the Sociology and Planning Stream, Section 27 of the Jubilee A.N.Z.A.A.S. Conference. University of Adelaide, Australia. 12-16 May 1980. My thanks go to Nick Perry (of Sociology Department. University of Auckland) and Ryde James (Forest Research Institute. Rotorua) for their comments on earlier drafts of this paper. has brought about an increased awareness among sociologists that we have played only a very minor role in influencing social policy (cf. Donnison, 1978). Our activity has been largely restricted to the provision of ’expert’ reaction