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Forest quality: assessing forests at a landscape scale Three main assessment criteria are used: authenticity, Earthscan Forestry Library.
Table of contents
- Forest quality : assessing forests at a landscape scale
- About this book
- Jean-Paul Jeanrenaud
- Forest Quality
Any moves by governments to impose economic disincentives on the use of fossil fuels could make oil palm and many other renewable sources of energy and hydrocarbons much more attractive with consequent increases in demand for land upon which to cultivate them. In the face of such increased competition it would seem prudent to maximise the benefits that we can derive from forests and this must involve maximising the range of products and services, although not necessarily on the same site.
Technologies that were critical to achieving sustainability in the past may become less important under some scenarios for the world's forests in the future. We take a contrary view to that of the World Resources Institute Bryant et al.
Forest quality : assessing forests at a landscape scale
We conclude that the frontier logging of relatively remote areas in the tropics, which has been a prominent feature of the timber industry in the late 20th century, may become less important in the future. We base this assessment on the fact that the technological requirement for large-diameter low-density hardwoods, common in many South-east Asian and African forests, will decline at the same time as the difficulties of exploiting the remaining stands of these forests increase.
The technological problems which made the more highly diverse and higher wood-density timbers of Papua New Guinea and South America less attractive in the past have largely been solved. However, demand for the products of these forests will be limited by the cost of extraction.
Once the forests in more accessible areas close to roads, rivers and ports have been exploited, any cost advantage that these forests might have had will be rapidly eroded. We expect them to become less able to compete with the outputs of the rapidly expanding plantation sector in the tropics and subtropics. In contrast to rising costs and declining quality of logs from natural forests, the volume and quality of plantation material will continue to improve while technological advances in plantation silviculture and wood processing continue to lower unit production costs. Some specialist products e.
Even if plato , scrimber, valwood and other technologies fail commercially, the search continues for technologies to make high-value products out of cheaper and more readily available fibre. At present about 15 per cent of the world's industrial wood production comes from about 25 million hectares of fast growing plantations located in both tropical and warm temperate countries. High-yield forestry is a reality and the biological ability to shift most wood production to plantations exists and can be put into practice if prices of industrial wood rise high enough to justify it.
In this context, the prime motivation for maintaining natural forests may be for amenity and environmental services in richer countries, and for non-timber forest products NTFPs and subsistence goods in poorer countries. However, it seems unlikely that logging of natural forest will disappear completely. Even in the most developed economies, the existence of forest industries, the cost of transporting timber products, and the desire to maintain employment in rural areas leads to continued logging of natural forests even when these are also valued highly for environmental services and amenity values.
There will always be some areas of natural forests where the returns from logging are sufficiently high, and costs low enough, for them to be competitive with the plantation industry Figure 3.
Maintaining the environmental and amenity values of natural forests will not be cheap, as significant investment and operating costs must be paid, either by the users directly, or by the public at large. In some cases, costs may be paid from timber receipts on these or other forested lands, including plantations , but there is no inherent reason why timber revenues should pay for amenity uses.
However, alternative sources of funding are often unavailable, and timber revenues represent the usual way to finance the maintenance of many other forest services. Figure 3. Schematic representation of the inflexion in the forest area curve which occurs when thresholds of economic and social development are exceeded. What will dictate the management of the remaining natural forests in the 21st century?
In the past, forecasts of future timber needs have been an important consideration in determining the extent of national permanent forest estates. If timber is increasingly to come from plantations, one might expect that this would lead to a reappraisal of such policies, and to a reduction in the area of natural forest. However, few countries have responded in this way. Rather, they place renewed emphasis on the values of forest for amenity and environmental services at both the local and global levels. Thus several countries with little need to harvest timber from natural forests e.
A consequence is a situation currently found in much of Europe where the mean annual increment of forests exceeds actual or predicted demand for timber Solberg et al. There, forests are more valuable to society as aesthetic and amenity resources than as sources of industrial cellulose. An interesting question is the extent to which similar trends will eventually emerge in the tropics.
The answer to this question will depend on many factors originating outside the forest sector. Principal amongst these will be the rates of growth of both populations and economies, and the availability of alternative sources of employment for people who now derive their livelihoods from forests and forestry.
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It seems reasonable to assume that forest cover in countries whose economies are rapidly developing will in general follow a U- or reverse-J shaped curve, with forest areas declining until thresholds for industrial employment and the capacity to intensify agriculture and forestry are attained Figure 3 See for example Capistrano The World Bank predicts that four of the most important tropical forest countries Indonesia, Brazil, India and China will join the world's largest economies early in the 21st century.
Past trends suggest that attainment of this level of development may herald the bottom of the curve, and that decline in forest area may cease. However, one difference in these and many other tropical countries is that there may still be a large proportion of the population whose per capita income remains much lower than in those industrialised countries where forest areas are now expanding.
About this book
It is difficult to determine the point at which a reversal of the deforestation trend might occur. Such predictions are complicated by the fact that conditions within countries differ so greatly. However, it seems reasonable to anticipate that the tendency to deforest should cease when countries graduate into the "middle-income category". Important issues relate not only to where the minimum occurs, but also what its value is, what the recovery rate is, what the eventual equilibrium forest area may be, and how these points may be influenced by policy and technology.
One of the critical questions for biodiversity is whether the forest area has to decline almost to zero before the response is triggered.
It seems possible that within a couple of decades, the "tiger economies" of South-east Asia and other countries with rapid economic growth will attach a value to the biodiversity and watershed protection functions of some forests that will be higher than the potential revenues to be derived from these forests for timber production.
This optimistic scenario would result in economics succeeding in achieving the objectives set out in many national forest policies where regulation has manifestly failed to do so.
However, this approach examines only national trends, and it is much more difficult to assess global trends, as the timber trade may export the trend to deforest. It is much more difficult to anticipate deforestation trends in Africa where economic growth is likely to be slower than in Asia and South America, and where most scenarios anticipate the persistence of a large population of poor subsistence farmers well into the 21st century. Throughout history most forest products have been harvested for use locally. Although international trade in forest products is as old as history, it was only during the colonial period that tropical timber began to be traded in large volumes.
The globalisation of trade in the mids resulted in large quantities of forest products entering the international trade from remote, sparsely populated areas in the tropics. As populations in the South increase and economies further develop we may see a reversion to the situation where an increasing proportion of forest products are consumed closer to their point of production. This will almost certainly be reflected in an increase in the proportion of world trade in forest products being South-South as opposed to South-North.
ITTO foresees an acceleration in the next few years of this trend towards increasing domestic log consumption in tropical countries ITTO If this is the case, and if the evolution of civil society in the expanding economies of the tropics parallels that in industrialised countries, we should see a situation where significant amounts of timber for local markets continue to be exploited from near-natural tropical forests.
However, forest plantation productivity has increased spectacularly during the past few decades and continues to do so Cossalter These gains have been realised in part through improved genotypes, but also through better silviculture and management of plantations. The implications for the land area required to service world timber demand are obvious Figure 4. Spectacular though they are, these technological achievements concerned a limited number of species grown on short rotations for the production of pulpwood, chips, industrial charcoal and small-sized wood for other industrial uses.
They represent a minute proportion of the tree species which can be planted in the tropics and subtropics. With few exceptions, timber species grown on medium and long rotations have not benefited from these technological advances.
Long rotations have not appealed to commercial investors and tree breeding and silvicultural research has focused largely on fast-growing species for industrial uses. Some reduction in rotation length can be achieved by intensive selection and breeding for rapid growth, and promising results in this regard have been obtained with species such as Araucaria cunninghamii, Araucaria hunsteinii, Gmelina arborea , several central American pines and Paraserianthes falcataria.
However there are limits to the potential of tree breeding, and it seems unlikely that timber species could exceed 40 cm dbh within 15 years. However, relatively modest increases in productivity will satisfy projected demands in the foreseeable future Figure 5; Brooks et al. Maintaining high yields from successive rotations of tree plantations while ensuring that the quality of the soil resource base and the resistance of the planting stock to pest and diseases is not declining is currently an important area of research for CIFOR.
Figure 4. This low productivity means that most of the world's forest need to be utilised to satisfy current demands for roundwood and fuelwood. A small increase in productivity in the more accessible and productive forests would free much forest from production obligations.
The increase illustrated is equivalent to average Swedish levels 4. Figure 5. Modest but realisable gains in productivity will satisfy projected in global consumption in industrial roundwood Data from Brooks et al. There is a strong case to be made for further refinement of reduced-impact logging RIL technologies for application in the extensive areas of the tropics which we believe will be kept under forest primarily for environmental and amenity reasons but where timber production will continue to be a viable option.
Most of the techniques embodied in RIL are not new, the innovation relates to the economics of using these technologies and to policies and incentives to promote their adoption. Increased use of these techniques should lead to a reduction in environmental impacts and greater productivity during future cycles. Thus, there is scope to promote the gains to be attained by reducing damage to trees and to the soil, by minimising breakage and waste, and by reducing capital and operating costs of machinery. Technologies outside the forest sector may also make a contribution towards sustainable forest management by reducing pressure for conversion of forest lands to other uses, by relieving demand for forest products, and by increasing options available to forest managers.
Developments in the wood-processing industries may contribute to greater efficiency and less waste in both the factory and the forest.
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