Silvicultural Options Research Articles

The role of nitrogen in declining scots pine forests (Pinus sylvestris) in the lowland of East Germany

Over the last decade, N inputs in pine ecosystems on the lowland of the former GDR have clearly increased. Agriculture plays a special role as a NHx emitter, because the whole lowland is covered with a network of large livestock farms. High N inputs cause an overnutrition of the pine stands with N, an accumulation of N in the soils, and as a consequence of the ensuing eutrophication, a drastic modification of the ground vegetation with a luxuriant growth of weeds and shrubs or of the vital herbaceous cover. The fine root quantity is reduced, also the mycorrhiza and the growth of pine. In many cases pine stands show a dramatical decrease of Mg nutrition. Finally, the limited range of silvicultural options is discussed, which are available to limit the progress of damage.

An Economic Evaluation of the Use of Oust for Herbaceous Weed Control in Loblolly Pine Plantations

Abstract Herbaceous weed control using Oust (sulfometuron methyl²) is economically efficient in loblolly pine (Pinus taeda L.) plantations given reasonable expectations about the long-term effect of the treatment on stand growth. Increases in the sizes of the growth increments following treatment that have been reported in the literature, and the economic returns this analysis shows are possible, indicate that investment in herbaceous weed control can be a prudent silvicultural option. South. J. Appl. For. 16(1):40-47.

Silviculture of plantation forest in central Nepal to maximise community benefits

Large-scale plantation establishment in the hill regions of Nepal did not commence until the early 1980s with the advent of community-forestry programmes. Most plantations are being established to supply the subsistence energy needs of the hill farmers, in whom the management of these forests will be vested. This paper describes a series of demonstration trials aimed at exploring a range of silvicultural options which can be adopted by villagers with the technical advice and assistance of the Forest Department. The options chosen are strongly influenced by the need to manipulate the forest to supply products most favoured by the farmers. While Pinus species are commonly used in the establishment of new plantations because of their pioneer survival characteristics, in many areas the stand composition can be altered so that the naturally regenerating broad-leaf species become dominant. The trials also demonstrate harvesting techniques aimed at obtaining regular supplies of usable biomass early in the life of the plantations. Mean annual increment for biomass productivity over the 13-year life of the plantation ranged from 4.52 to 7.23 t ha −1 year −1 across the six treatments tested.

Problems and opportunities for forestry within the European community - implications for research and development

A quasi-quantitative subjective assessment was made of the potential development of forestry within the Member States of the European Community, adopting a long-term perspective with a time horizon of 70 years. In making this assessment it was assumed that (a) the Community wished to lessen its dependence on external supplies of wood and wood-based products and (b) actions taken to lessen this dependence, by increasing its own wood supplies including the conversion of agricultural land, must take due account of monetary and non-monetary benefits of forests; an integrated approach linking production and utilisation with conservation, landscape and socio-economic factors embraced by rural development, would be obligatory. The study was in two parts, the identification of: (a) opportunities; and (b) the research-and-development requirements if the opportunities were to be seized. The opportunities for Member States of the European Community were assessed by developing matrices examining three land-use scenarios and three wood-production objectives. In general, the production of sawnlogs is likely to be ‘significantly’ increased by the use of improved (a) genotypes and (b) silvicultural techniques; it is less likely to be increased significantly by the conversion of agricultural land. Improved genotypes and silvicultural techniques will also increase supplies of industrial wood, the benefits being enhanced by the conversion of agricultural land. If punitive transport costs are to be avoided, yields of industrial wood, in areas of radius 70 km, would mostly be sufficient to warrant industrial installations using 4 × 10 5m 3 year −1 and -only to a lesser extent - installations needing 10 6m 3 year −1. In reality, the opportunities differ in the different regions of the Community. Relatively short-rotation forests/tree-crops, producing industrial wood, are likely to be concentrated in the Offshore (Eire 3 and the United Kingdom 4) and Continental Oceanic Regions, whereas forests in the Mediterranean and Alpine Regions will mainly have protective functions. High-quality, large-dimension sawnlogs will be produced in many parts of the Continental Oceanic Region, particularly the north and centre (Belgium, Denmark, most of the Federal Republic of Germany, western France and The Netherlands). Sixteen research and development requirements were identified. They are concerned with: the better utilisation of existing data and experience; forest decline; fire; stability of forest ecosystems; silvicultural methods, wood quality and end-use; integrated forest management; integrated evaluation of wood and non-wood benefits; marketing, and end-product and process innovation; reactions of the public to changes in land use; reactions of landowners to changes in land use including a consideration of incentives; collaborative forestry ventures; silvicultural options for afforesting agricultural land; responses of trees to stresses; early indications of the performance of mature trees; conservation of trees native to the European Community; and exploitation of genetic resources.

Alternate Strip Clearcutting in Upland Black Spruce: VIII. Shallow-soil Ecosystems and Their Classification

Shallow-soil sites in the Nipigon-Beardmore area of northern Ontario are widespread and pose unique operational problems for forest managers. Several working definitions of shallow soils are used in Ontario. More accurate regional definitions are required in order that silvicultural decisions for these sometimes fragile sites may be refined or new ones developed. Harvesting and silvicultural options for shallow-soil sites are limited in the North Central Region.A program of Forest Ecosystem Classification (FEC) for the North Central Region has been designed to provide better understanding of shallow sites and a framework of standardized definitions. The FEC describes several shallow-soil types that occur over boulder pavement or bedrock, and differentiates mainly on the basis of depth-to-rock contact, surface organic material thickness and texture of the primary mineral soil particles. Operational application of this classification may require identification of complexes of shallow-soil types.

Stand reduction of red pine by Gremmeniellaabietina

Damage to red pine (Pinusresinosa Ait.) by the North American race of Gremmeniellaabietina (Lagerb.) Morelet occurs primarily within the first 10 years after plantation establishment when mortality of 50 to 100% is common. Damage in the residual stands occurs as reduction in bole diameter at 1.3 m, increase in effective plantation edge as a consequence of the infection-pocket mode of disease etiology with consequent decrease in natural pruning and increase in branch diameter, and reduction in stand uniformity in terms of stem distribution and stem size. Not only are quantity and quality of products reduced but disruption of stand uniformity sharply limits the management forester's scope of silvicultural options.

Constraints on the natural regeneration of tropical moist forest

This paper reviews natural regeneration in tropical rain forests in terms of constraints. A potential for regeneration normally exists and silvicultural intervention should ideally take account of natural succession. Success is more likely with forests tending to single dominance or when the desirable crop species grow rapidly in response to light. Natural regeneration systems are currently unfashionable but are suggested as often being still the most appropriate methods of regenerating tropical forests. The forests are vulnerable to fire and as they contract in size animal populations exert increased stress. Providing biological rhythms are accounted for there seem to be few constraints to crop replacement. Exploitation of the forests often damages regeneration when logging is uncontrolled. This suggests more logging control is necessary to increase the availability of silvicultural options. Examples of seedling persistence, felling rules and silvicultural decisions are given for the dipterocarp forests of Sabah.