In temperate forest areas in Europe, the Plenterwald system has its supporters in certain regions, but the traditional approach of even age class forestry is still dominant. Experienced foresters and forest owners have practised this system for generations. Forests managed under these types of systems are aesthetically attractive and valuable, but have lost many of their natural characteristics. It is not surprising that foresters and private forest owners feel confused and are reluctant to start transforming their forest estate from easily managed pine or spruce monocultures to a complicated mixture of hardwoods. Criticism of the current systems in place is strong, but the costs of such a transformation would also be very high.
The United States of America lacks much of the European-style legislation governing the management and utilisation of forest resources. Consequently, many non-industrial private forest owners in the United States of America are reported to harvest the forests without any plans for reforestation. They are believed to not want to invest in reforestation because of the long time involved in such an investment. Small woodland owners in Canada have been similarly criticised for not acting sustainably. This is a serious problem in the United States of America, where non-industrial private forest owners own a significant share of the resource.
A further complication in the United States of America is that loggers often buy wood standing from private landowners and pay little attention to the silvicultural consequences of their harvesting activities. Laws, regulations, tax structures and policies in the United States of America have also been cited as compromising the ability of private landowners to implement sustainable forest management, rather than encouraging it.
The Sustainable Forestry Initiative, developed by the AFPA, includes promising measures to promote the training and education of loggers and to inform landowners about appropriate forestry practices. It is an interesting to observe however, that private organisations have taken on this responsibility in the United States of America where it would typically be taken on by state agencies in European countries.
Temperate forestry in countries such as Chile and New Zealand is strongly focused towards large-scale plantation forestry, mostly carried-out by large corporations. The main aim is to cultivate fast growing trees on short rotations to produce high levels of wood raw materials for mills situated nearby. Sustainable yield is an important consideration in these operations, but broader issues, such as environmental impacts, should also be considered. In New Zealand the forest industry is committed to protecting indigenous biodiversity, conserving threatened species and to avoiding replacing natural forests with plantations. But in Chile the latter issue is still under debate.
In terms of their biology, the silvicultural systems currently used in managed boreal forests generally work well if they are properly selected and implemented. However, there are many examples of past unsatisfactory management. This is partly because the tradition of sustainable forest management in boreal forests has not been practised for very long, except in some parts of the Nordic countries.
However, even in some parts of the Nordic countries, intensive forest management, in the modern sense, did not start until some 50-60 years ago. In these areas, forest management was developed gradually, based on research and experience by trial-and-error. Forest companies and the state took a lead in this process; an approach which was also followed later in Canada and the Soviet Union. As a result of all this experience and all these efforts, boreal forest silviculture, aiming at cultivating high yielding forests, is now very successful and can be carried out in most areas. Any failures that arise now will largely be as a result of poor management (e.g. due to a lack of knowledge, experience, interest and/or resources). The economics of forest management may be partly to blame for this.
In general, the broader concept of sustainable forest management now seems to be accepted and accomplished in most boreal forest operations in western countries. Many forest owners and organisations have committed themselves to far-reaching measures for nature conservation and most large forest owners try to conduct their nature conservation efforts at the scale of the forest landscape. Furthermore, work is constantly underway in western countries to develop better standards for forest nature conservation. In the Russian Federation, the current magnitude of problems outside the forestry make it unlikely that this country will be implementing sustainable forest management in its broadest sense in the near future.
The present objectives of forest management have become more complex and the question of what constitutes good silviculture is constantly debated and becoming more vague. There are two fundamentally different views about how forest management systems should be adapted to meet nature conservation objectives. Some believe that improvements in forest management should aim to increase sustainable yields of timber and nature conservation values, i.e. that the two developments should proceed in parallel. An opposite view is that improving nature conservation ultimately involves doing less after harvesting, saving in silvicultural and other costs in the short-term but, ultimately, leading to lower production volumes in the long-term. Currently, the latter approach seems to be gaining ground with both small and large forest owners leaving areas alone after harvesting. This may result in an increase in forest areas that are in an unsatisfactory condition.
Modern, far-reaching nature conservation policies also have their price, which many forest owners currently seem ready to pay. Large forest owning companies in Sweden estimate that adapting to the current requirements for sustainable forest management has lead to a decrease in their annual allowable cuts of some 10% (compared to an intensive forest management option without any restrictions). Large forest owning companies in North America seem to arrive at similar figures. In addition to lost revenues, there are also increases in operational costs associated with the implementation of sustainable forest management.
A question often raised is whether clearfelling large tracts should be avoided because of negative environmental consequences such as the elimination of biodiversity. It is true that the result of poorly planned and carelessly accomplished clearfelling can be criticised from various angles and that there are many examples of bad practices in all countries. However, there are also some good environmental reasons to favour clearfelling in many managed forests, not only because the method is operationally simple and cost effective. Some forest ecosystems are adapted to and even need catastrophic disturbances to retain their natural vitality. Under natural circumstances, the most important rejuvenating factor in nearly all forest ecosystems is the wildfire (often at a large-scale). Conditions favourable for wildfires dominate in many boreal forests, but fire hazards also occur frequently in many temperate zone forests.
Clearfelling imitates, to some degree, the effect of fire with one difference: that the trees are harvested before nature consumes them. However, simply clearfelling a site will not simulate the effect of natural fire. But, studies are showing how this practice can be adapted to meet environmental demands. For example, a naturally burnt area will contain lying or standing dead trees and some surviving trees and tree clumps. Current clearfelling practices should emulate this by similarly leaving live and dead, standing and fallen trees. Shelters along streams, lakes and sometimes roads, should also be left during harvesting operations. Controlled burning of clearfelled areas after harvesting is sometimes carried out as a reforestation measure, but nowadays it is increasingly used to enhance biodiversity by encouraging the survival of organisms that depend on this type of event.
Another reason in favour of the clearfelling practice is that experience has shown (not least in the Nordic countries) that, where selective harvesting systems have been practiced over long periods of time, the result has been detrimental and even catastrophic for the condition of the forest.
Forest managers and policymakers around the world are actively trying to reshape and broaden the management options available. Selection forestry has become a topical issue as it represents the main alternative to clearfelling. There is no doubt that the method is clearly useful in some forest environments and under special conditions. For example, it is successfully used in hardwood or mixed forest stands where the aim is to produce old and very large, valuable trees. It is also a method to use when, for environmental reasons, it is important to maintain a closed forest cover after harvesting. However, selective harvesting has some weaknesses compared to clearfelling. It generally results in lower yields (except possibly in terms of the yield of large sized trees), harvesting is usually more labour intensive (and, consequently, expensive) and the trees that will be cut are spread over larger areas. This increases transportation costs and the requirement for forest roads. Because the work is more difficult, there is also a greater risk of failure.
The most important objection against a more widespread use of selection harvesting though is that this type of forestry is biologically inappropriate on forest sites where the natural ecosystem is fire related and/or where light demanding tree species are being cultivated. This makes it inappropriate for nearly all of the boreal forest and a fair portion of the temperate forest as well.
The general development in western countries is towards the increased use of mechanised and labour saving production techniques. This is as true for the forestry sector as for any other. This trend favours the continued use of clearfelling. Selection forestry has an important role to play, but even age class forest management systems (that will most likely be developed further to meet environmental concerns) are likely to continue to dominate in the future.
Most of the industrial roundwood consumed worldwide is produced in the temperate and boreal forest zones. They will therefore, continue to be utilised for timber production for a long time to come. It would neither be possible or desirable to try to substitute a significant portion of this harvest with wood from other sources. Such an attempt would most likely lead to overharvesting elsewhere and just move environmental problems to the tropical countries.
Where new forests are actively created after harvesting natural forests, this can be considered as a sustainable development as long as this is carried out in a responsible way. This is currently continuously occurring all over the world and a major debate at the moment is to what extent and under what conditions should this continue. Society is still a long way from answering this question, but it should be noted that there is an enormous area of natural boreal forest that is still untouched and is not likely to come under management in the foreseeable future.