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... The pitch canker pathogen, Fusarium circinatum , has major impacts on production in pine nurseries and plantations in South Africa. Thus far, efforts to reduce local spread have focused on rouging of infected pines and sanitation to eliminate local sources of inoculum. Although the host range of F. circinatum was thought to be limited to pines and Douglas-fir, recent studies in California indicate ...
... For many years foresters have been using statistical probability density functions to describe and characterise stand structure. Predicting the current and future yields of a stand is essential for successful stand and timber management. Implicit prediction of current yield is accomplished by using diameter distribution methods. All diameter distribution yield systems predict the number of trees p ...
Fusarium circinatum; Pinus patula; clones; foresters; forests; greenhouse experimentation; greenhouses; open pollination; pathogens; screening; seedlings; seeds; trees; South Africa
Abstract:
... Since the first appearance of Fusarium circinatum in South Africa in 1990, foresters have been challenged with poor field survival of Pinus patula seedlings at establishment. One of the best long-term solutions is to improve the genetic tolerance of P. patula to infection by the pathogen. Currently, large numbers of families are routinely screened for their tolerance to F. circinatum by infecting ...
... The primary symptoms associated with Fusarium circinatum infection in pine seedling nurseries are root and collar rot, shoot and tip die-back and seedling mortality. Management of this pathogen in nurseries usually involves the integration of various strategies relating to sanitation, insect control and fungicide treatment. The overall goal of this study was to use quantitative real-time PCR (qPCR ...
... In eucalypt plantations in subtropical Australia, Eucalyptus dunnii exhibits greater diameter increment after thinning than more shade-tolerant Corymbia citriodora . To elucidate the mechanism underlying this difference, we investigated relationships between tree leaf area and sapwood area following thinning in 11-year-old E. dunnii and C. citriodora plantations. There was no significant differenc ...
conservation areas; ecosystems; edaphic factors; forests; national parks; savannas; soil; species diversity; vegetation structure; woodlands; woody plants; Zimbabwe
Abstract:
... Despite the importance of edaphic factors in influencing woody vegetation diversity and structure in savannas, there is still limited research on the topic across most savanna ecosystems. Here we investigate the differences and/or similarities of woody vegetation diversity and structure across areas with different edaphic factors (i.e. soil group) in Gonarezhou National Park, Zimbabwe. We stratifi ...
Tectona grandis; equations; forests; models; prediction; site index; trees; variance; India
Abstract:
... Data from 27 remeasured sample plots were used to evaluate dynamic base-age invariant site index models for teak (Tectona grandis) forests in Karnataka, India. The data were obtained in observational field studies covering a wide range of sites in Karnataka and provided up to three interval measurements per plot. All the functions were fitted simultaneously using iterative seemingly unrelated regr ...
Fusarium circinatum; Pinus patula; forestry; forests; fungi; inoculum; mortality; pathogens; plant establishment; seedlings; water stress; South Africa
Abstract:
... Fusarium circinatum is an important fungal pathogen of Pinus species. In South Africa, it is the most significant pathogen of Pinus patula seedlings in forestry nurseries where it presents a substantial constraint to productivity and can continue to cause mortality in-field for up to two years after establishment. This study describes the results from two trials where P. patula seedlings were inoc ...
... There is a limited availability of land for the expansion of South African black wattle plantations. One way to increase productivity is to ensure the survival of seedlings during regeneration, thereby increasing the stocking of compartments. Soil invertebrate pests constitute one of the important causes of seedling mortality. The effect of different plantation residue management practices on the ...
... In this study we tested the predictive ability of canopy area in estimating wood volume in deciduous woodlands of Zimbabwe. The study was carried out in four sites of different climatic conditions. We used regression analysis to statistically quantify the prediction of wood volume from canopy area at species and stand level using field data. Our results revealed that canopy area significantly (P < ...
Pinus massoniana; aboveground biomass; allometry; forests; models; tree and stand measurements; trees; China
Abstract:
... Quantification of forest biomass is important for practical forestry and for scientific purposes. It is fundamental to develop generic individual-tree biomass models suitable for large-scale forest biomass estimation. However, compatibility of forest biomass estimates at different scales may become a problem. We developed generic individual-tree biomass models using a mixed-effects modeling approa ...
Fusarium circinatum; Pinus patula; breeding; crops; forests; fungi; genetic variation; greenhouses; hygiene; mortality; open pollination; screening; seedlings; trees; South Africa; United States
Abstract:
... The pine pitch canker fungus, Fusarium circinatum , has caused large-scale mortality of Pinus patula Schiede & Deppe ex Schltdl. & Cham. crops in South African nurseries. This disease is now managed with strict hygiene practices and mortality in commercial nurseries has been drastically reduced. During the last 10 years, however, the disease started to manifest in the field, impacting on post-plan ...
conifers; forest inventory; forests; models; trees; United States
Abstract:
... To demonstrate the utility of mixed-effects height–diameter models when conducting forest inventories, mixed-effects height–diameter models are presented for several commercially and ecologically important conifers in the inland Northwest of the USA. After obtaining height–diameter measurements from a plot/stand of interest, these mixed-effects models can be calibrated to produce localised individ ...
Nothofagus dombeyi; forest resources; foresters; growth models; landowners; secondary forests; site index; trees; Andes region; Chile
Abstract:
... Nothofagus dombeyi grows in a wide variety of sites. The information about its productivity is still scarce, which makes it difficult for foresters and landowners to take decisions about the best practices to maintain and/or improve the goods and services derived from the forest. The aim of this study was to construct dominant tree height functions and site index curves for secondary forests of No ...
data collection; forests; harvesting; humans; models; planning; prediction; regression analysis; sawlogs; skidders; softwood; supply chain; trees; South Africa
Abstract:
... The objective of this study was to develop predictive models for cable and grapple skidder wander ratios, travel speeds (loaded and unloaded), and productivity in softwood roundwood sawtimber harvesting operations. For field data collection, the study utilised on-board computing systems supported by manual time study. Four-hundred and twenty-seven extraction cycles over varying terrain and tree si ...
branches; forest management; forests; models; prediction; tree and stand measurements; trees; woodlands; Tanzania
Abstract:
... Volume of trees is an important parameter in forest management, but only volume models with limited geographical and tree size coverage have previously been developed for Tanzanian miombo woodlands. This study developed models for estimating total, merchantable stem and branches volume applicable for the entire miombo woodlands of Tanzania. We used data from 158 destructively sampled trees, includ ...
... This study was conducted to develop a diameter distribution model for Pinus kesiya stands in Benguet province, Philippines, using the percentile-based Weibull model. The performance of the different equations was examined using evaluation statistics such as the fit index (FI) and root mean square error (RMSE). Results showed a FI range from 0.48799 (minimum diameter) to 0.94071 (95th diameter perc ...
Fusarium circinatum; Pinus patula; Pinus tecunumanii; bags; bark; forests; growing media; hybrids; hydroponics; mortality; pathogens; sand; vegetative propagation; South Africa
Abstract:
... In response to the Fusarium circinatum pine pathogen threat in southern Africa, research has been conducted on the development of F. circinatum- tolerant P. patula and P. patula hybrids. The objective of this study was to investigate the propagation potential of these taxa in two vegetative propagation systems, hydroponic sand beds and polythene bags with composted pine bark growing medium. Signif ...
... At least 200 000 m ³ of timber is harvested annually using semi-mechanised harvesting systems on the Viphya forest plantations in Malawi. Although these systems have long been used on the Viphya, no investigation on their productivity has so far been reported. Additionally, the absence of localised productivity analyses in Malawi has created a paucity of information on appropriate timber harvestin ...
Fusarium circinatum; Pinus patula; containers; control methods; crops; discoloration; forests; hygiene; inoculum; mortality; open pollination; pathogens; planting; root systems; sanitation; screening; seedling growth; seedlings; steam; Southern Africa
Abstract:
... Fusarium circinatum is a pathogen causing serious post-planting mortality of Pinus patula seedlings in southern Africa. Containerised planting stock that is asymptomatic but associated with F. circinatum in the nursery is thought to be the cause of this problem. The aim of this study was to determine if re-use of seedling containers could be a source of inoculum resulting in asymptomatic planting ...
harvesting; logging; Araucaria araucana; saplings; juveniles; seedlings; principal component analysis; mature plants; shade; stand density; stand basal area; Nothofagus pumilio; stand structure; forests; Chile
Abstract:
... In this study we examined the current structure and regeneration status of mixed Araucaria araucana–Nothofagus spp. stands that had been logged 20 years ago. We measured stand density of saplings, juvenile and adult trees, as well as stand basal area of A. araucana and Nothofagus spp. in 69 plots distributed in five sites in order to characterise diameter distributions using a Weibull function. Ar ...
... A performance comparison of seven-year-old individuals of 13 Casuarina species/provenances in terms of survival, growth (diameter, height and volume), wood basic density and wood biomass was undertaken at Kongowe, Kibaha, Tanzania. The trial was laid out using a randomised complete block design with four replications. The results showed significant differences (P < 0.0001) in all parameters. Casua ...
application timing; fire break; forests; glyphosate; paraquat; pelargonic acid; risk; screening; spraying; summer; vegetation cover; South Africa
Abstract:
... Over the past 31-year period, about 18 700 ha annum ⁻¹ of planted forests in South Africa have been lost through fire. In forested areas where the risk of fire entering compartments is always high, fire-break tracer lines are prepared by spraying with a suitable herbicide such that the adjacent vegetation is still 'green' when these tracer lines can be burned. Once the vegetation between these tra ...
... Subsequent to 1950, commercially propagated and non-native trees, including Pinus, Eucalyptus and Cupressus species in Colombian plantations, have been damaged by several native defoliating insects, residing mainly in the Lepidoptera (Geometridae), Phasmatodea (Heteronemiidae) and the Hymenoptera (Formicidae). We report on the relatively recent appearance of three important and damaging new insect ...
tree and stand measurements; trees; provenance; Vachellia nilotica; stand basal area; forests; Senegal; Pakistan; Yemen; Niger
Abstract:
... A provenance trial of Vachellia nilotica (Acacia nilotica) was conducted in Niger in order to assess variability in growth among 10 provenances from Africa (subsp. adstringens from Niger, Senegal and Cameroun) and outside the continent (subsp. indica from Pakistan and Yemen). Tree height, diameter at breast height and crown diameter were measured 15 years after trial establishment. Comparison of b ...
Pinus patula; forests; modulus of elasticity; modulus of rupture; pith; prediction; sawlogs; softwood; trees; wood properties; South Africa
Abstract:
... The objective of this study was to examine the variation in and intercorrelation among wood properties determining the suitability of 16- to 20-year-old South African-grown Pinus patula trees for structural timber. A total of 1 112 sawn boards from 340 logs, 170 trees and 17 different compartments were examined. Sawlogs were taken from two height levels from each tree. The mean modulus of elastici ...
Pinus patula; Podocarpus; afforestation; canopy; evaporation; forest plantations; forests; fynbos; grasslands; introduced species; models; planning; planting; soil; transpiration; trees; water management; water use efficiency; South Africa
Abstract:
... A number of studies undertaken in South Africa to quantify the green water-use (total evaporation) of introduced commercial forestry species have shown conclusively that green water-use from commercial forest plantations is substantially higher than from the original grasslands or fynbos that were replaced by afforestation. Green water can be categorised into productive (transpiration) and non-pro ...
community forestry; forest industries; forests; issues and policy; supply chain; timber production; wood; India; Philippines
Abstract:
... This paper uses the 'input–output analysis' technique to investigate why the Joint Forest Management program in India has expanded while the uptake of the Community-based Forest Management program in the Philippines has been relatively slow. The forward linkage of the forestry sector with downstream industries in the Philippines was found to be weak when compared with India. In contrast, the wood ...
business enterprises; community service; employment opportunities; forestry; forests; plantations; stakeholders; supply chain; unemployment; South Africa
Abstract:
... This study investigates the possible socioeconomic impact of the phasing out of nearly 22 500 ha of plantations within the Southern and Western Cape regions of South Africa as a result of a decision made by government in 2000. Data was collected in 2007 from three plantations (one near Grabouw in the Western Cape, and two near George in the Southern Cape) managed by Mountain to Ocean Forestry (Pty ...