René G. Fontaine
R.G. Fontaine, former Director of FAO's Forest Resources Division, was a member of the Organization from 1946 until 1973.
This article commences a series in Unasylva on the management of humid tropical forests. Some readers may wonder why Unasylva should concentrate on this subject, which has already been debated on so many occasions without significant progress. And indeed deforestation, degradation and mismanagement of tropical forests continue, while successful models of integrated sustainable development and conservation of humid tropical forests remain desperately scarce.
Needless to say, FAO, which is committed to assisting tropical countries in instituting sound forest management practices, is most concerned about this situation. Hence this series of articles.
Two attitudes must be overcome at the outset. First, some contend that there is no point in striving for the management of tropical forests when so little is known about their functioning and the consequences of their manipulation. Here it is worth remembering that forest management started long ago in temperate countries at a time when very little, if any, scientific evidence existed as to how to use and regenerate forests. Governments and large landholders realized that this was the only way to reverse the declining supply of much-needed forest products (fuelwood for industries, timber for the navy) and services (soil and water conservation). A similar situation now prevails in many tropical areas. Here again, governments and communities concerned cannot simply wait for decades of fundamental and applied research before starting forest management. In no way should lack of scientific knowledge be used as a pretext for not starting forest management now.
Management of humid tropical forests
Second, others claim that tropical forests are not a renewable resource and therefore cannot be managed as such. It is true that it is not possible to utilize a primary forest and keep the same mix of species and age or size classes over time. However, silvicultural and other management practices can be developed in a conservative manner to sustain an approximately equal amount of goods and services, including genetic diversity.
In addition to publishing this series of articles, FAO is pursuing an active programme on tropical forest management. In 1985 it published Intensive multiple-use forest management in the tropics based on four case-studies in Ghana, Honduras, Kerala (India) and Trinidad and Tobago (the Kerala case-study was published in a separate document entitled Intensive multiple-use forest management in Kerala (India)). Three syntheses on the present situation and trends of forest management in the main tropical regions will be published for tropical Asia (end 1986) and for tropical Africa and tropical America (both in 1987). In addition, many tropical countries request FAO's assistance for the formulation and implementation of forest management projects for which the Organization mobilizes the best expertise available.
The first article in this series is by R.G. Fontaine, a former Director of FAO's Forest Resources Division, who reviews the main biological and socio-economic constraints facing the management of humid tropical forests. Unasylva invites its readers to participate in this exchange of information by submitting comments and articles on this important topic.
LOGGING IN SRI LANKAN RAIN FOREST long-term goals must be formulated
· The concept of management rests essentially on the perception of the forest as a renewable resource which, if carefully manipulated in accordance with the limitations imposed by vegetation, soil and climate, can provide the goods and services required by society on a sustained basis.
In this article I propose to put forward some thoughts on the possibilities and limitations of management of the moist tropical forests in accordance with the characteristics of this ecosystem and with the new economic and social conditions emerging in the regions concerned. Recent international meetings, mainly under the aegis of Unesco, UNEP and FAO, have examined the problems of development of the moist tropical forests, placing emphasis upon the institutions to be created and the research to be undertaken. Some authors have questioned the validity of managing moist tropical forests because the effort is so complicated and yields such low returns, and have proposed that these forests be replaced by artificial plantations of fast-growing species, assuming - sometimes too hastily - that such plantations would be feasible and renewable. I consider that the importance of the tropical forests is incontestable given their productivity; the diversity and technological qualities of their timber, and their role in the development of local communities and in the socio-economic development of developing countries, not to mention their potential role as a source of energy and in maintaining the equilibrium of the biosphere.
Moist, tropical evergreen and semi-deciduous tropical forests cover about 900 million ha, and the production of tropical sawlogs and veneer logs, at present about 140 million m³, represents about 60 percent of world production of hardwood logs.
This article will attempt, primarily on the basis of recent scientific work, to delineate the principal ecological and socio-economic constraints with which the management of moist tropical forests is confronted.
When a moist tropical forest ecosystem is manipulated, two types of constraints are encountered, some internal to the system and others external and dependent on the socio-economic framework.
Traditional forest management is based on: the definition of compartments and series that are ecologically as significant as possible; the reference to a "normal" forest (a forest consistent with the goals of management); knowledge of regeneration and succession; the need to maintain soil fertility and genetic diversity; and, knowledge of the productivity of the sites and species. It will be seen that it is not easy to define and implement these elements in the humid tropics.
The spatial heterogeneity of moist tropical forests, in which various stages in the succession coexist side by side, has been underlined by many authors. This heterogeneity is the result, over a long period of time, of physico-chemical conditions (soil and climate) and of evolution, co-evolution and competition among species. The first factors - soil and climate - are not necessarily predominant. In effect, there seems to be a continuum: the structure of the forest does not necessarily change significantly with changes in soil and climate. This simple reminder indicates the difficulty in making a meaningful division into compartments for which silvicultural treatment could be programmed in advance.
It is logical, after logging, to make a diagnostic sampling to determine whether enough seeds and seedlings of valuable species are available and, if necessary, to arrange for replacement and enrichment planting. However, it has often been noted that such sampling is unreliable and that it is difficult to replicate the "normal" forest which, in the traditional management of temperate forests, is that which corresponds to achieving stated management goals (although there are exceptions to this rule, such as the Okoume forests in central Africa and the dipterocarp forests of southeast Asia, which are examples of particularly stable stages in the succession, or of edaphic forest formations). Generally in the moist tropical forests it thus appears difficult to orient activities toward a stand that conforms to the aims of the management proposed.
Soil-vegetation relations are, as is known, very complex by nature. In the moist tropical forest ecosystem a great part of the nutrients available (about four-fifths) are stored in the biomass - mainly the biomass above the soil surface - as regards nitrogen, phosphorus and most of the cations. But it is only recently that the storage mechanisms and the role played by the symbiotic associations between fungi and plant roots have become well-known. These mechanisms are found in the root layer and in the humus on the soil surface, where a rapid development of small roots prevents leaching of nutrients produced by the decomposition of dead organic matter: the action of mycorrhizal fungi facilitates capture by the plants of the nutrients found in the decomposing litter; and algae and other micro-organisms immediately absorb nitrogenous nutrients and retain them until their death and decomposition. All interventions in the plant cover that prevent the roots from immediately capturing nutrients released by the decomposers, will favour leaching and result in impoverishment of the soil and the stands for long periods.
TROPICAL RAIN FOREST NEAR MANÁUS the constraints to managing it are considerable
Species diversity is another critical characteristic of the moist tropical forests, imposing certain constraints on their management if the genetic resources are to be adequately conserved. Conservation strategies are rendered difficult because of lack of knowledge on intraspecific variation in tropical forest species. Some authors have proposed formulas for calculating the area to be protected in order to ensure the conservation of species of which the great majority are represented by only a few specimens per ha or per km², which have led to recommendations for relatively large areas for reserves of moist tropical forest. These reserves can be surrounded by managed forests which would then constitute a buffer zone between the zones where all utilization is prohibited and those that can be freely used, with the utilization of the managed zones being carefully monitored.
Little is known about the reproductive mechanisms of the moist tropical forest species. Seed dispersal processes vary among species, and seed germination and plant establishment will occur only under given conditions. Thus the species of secondary forests, usually light-demanding, have seeds with long dormancy and vitality, while primary forest species produce seeds that are shorter-lived and need considerable cover. Finally, although some authors think that regeneration is not a random process, but is foreseeable, others consider hat, although distribution of the species in the first stage of regeneration may be modified by environmental factors, it is essentially a matter of chance.
Considerable research therefore remains to be done on the mechanisms of secondary succession and formation of the final stands after modification of the original forest, either through natural causes or through human action.
Finally, there are two further constraints, one concerning the relative stability of the moist tropical forest ecosystem and the other the lack of data on their growth and yield. As regards the first, it has often been thought that the stability of an ecosystem depends on its diversity: the moist tropical forest ecosystem should therefore be stable. However, this does not always hold true. In fact, if by stability is meant the ability to return to an initial stage after a disturbance, the moist tropical forest is stable in the event of spot or linear disturbances of short duration or of limited extent, but not when the disturbance affects a larger area and goes beyond a certain threshold. This must be borne in mind in the manipulation and utilization of these forests.
As regards the second constraint, there is a serious shortage of information on primary productivity for the moist tropical zones, and it is limited to a very small number of sites. As for the estimation of forest volumes and their growth, volume tables and measurements exist in great numbers but much remains to be done in this area.
THREE MONTHS AFTER LOGGING this Ugandan forest needs management
FOREST ENRICHMENT, 2½ YEARS LATER the result of positive management
It is obvious that the internal constraints to forest management are compounded by others that are to be found outside the physical and biological system, and that are related to people, that is, to the socioeconomic framework. We shall rapidly present the five most important of these constraints.
First, there are the epidemiological constraints. In this regard the consequences of rapid and uncontrolled destruction of a moist tropical forest must be considered. The living organisms that make up the forest ecosystem have established among themselves certain complex relationships that possess a certain equilibrium. During development operations the possibilities of contact between people and an unfamiliar environment will increase, and disturbances in the balance of the moist forest system may have dramatic consequences on the human community. In moist tropical forests parasites and viruses are present at all levels in the vegetation and in the wildlife, especially among the arthropods. Human beings can therefore be exposed to debilitating or even fatal infections.
The problems posed by ergonomics and equipment in the tropics have also attracted the attention of many research workers, and international institutions such as the International Labour Organisation (ILO) and FAO have devoted in-depth studies to them. It is now known that in the tropics a person's productivity may be up to 50 percent lower than in the temperate countries, and that labourers need special diets, clothes and equipment. As regards equipment, mention must also be made of the damage that can be caused to the environment and soil stability by the careless use of heavy equipment.
Communications and cooperation among various enterprises in the forestry sector also constitute a group of constraints that must be borne in mind. In the temperate zones, particularly in Europe, there is no very close correlation between the resource and the siting of processing industries because of the dense communication network. But in the moist tropics, where roads are lacking, the problem becomes crucial. Every logging enterprise has to build its own transport network. In addition, utilization of the forest can be intensified only if the species harvested are grouped according to prospective uses. This calls in one way or the other for integration of the forest enterprises.
The absence of sufficiently large internal markets has posed and still poses serious obstacles to forest development in the tropics. Most of the production is absorbed by external markets and consists of a fairly limited number of species traditionally in demand in the industrialized countries; and of industrial wood consisting of a mixture of species for particleboard or paper pulp. Thus, it is now important for the tropical countries to develop an internal market - the only guarantee for a self-generated take-off of their economies - while continuing to export forest products to industrialized countries in order to obtain badly needed hard currency. To achieve this, it is necessary not only to use quality species, when there are enough of them, but also to be able to group species according to their potential end-uses so as to put larger quantities on the market and reduce the costs per m³ felled, transported and processed. This grouping of the secondary species by end-use which is now under way poses certain problems but is essential for the development of the forests.
Finally, institutional constraints are without doubt the most important; these derive mainly from questions related to forest ownership and tenure. In the developing countries, as a result of colonization, forests often belong to the state, and serious conflicts arise between the needs of the local populations and the objectives of a national forest policy. In many cases, it is appropriate to "communalize" forests near villages in order to involve local communities in their management and to get the forests to produce the goods and services these communities need. Of course, this does not exclude maintenance of state-owned forest area as part of the national infrastructure to ensure environmental stability and a supply of wood for national industries. Institutional changes that could be contemplated pose many questions: should management tasks be separated from public service tasks and, if so, to whom should they be entrusted? Should certain state forests be communalized on social or even economic grounds, while leaving the state forest administration responsible for their technical management? How can extension work be developed to inform the new owners about the possibilities and limits of forest management? How can research be combined with development within the framework of field operations of certain enterprises?
In some sectors, enterprises can be created, reoriented or even shut down fairly easily. This is not the case in the forestry sector which, because of its nature and its functions, does not lend itself easily to rapid changes. Moreover, some changes are irreversible or it may take the forest a long time to return to its initial stage: what is known about the influences of the forests thus prompts us to be prudent in our interventions. Consequently, a long-term view of the forest is necessary, which includes:
· defining and establishing a permanent forest estate to meet national and local requirements and to protect the environment;· the role of forests for rural communities;
· the relationship between forestry, agriculture and animal husbandry;
· constraints imposed by the city on urban and pert-urban forests; and,
· the relations between the permanent forest estate and parks and reserves.
These considerations can be summarized as the place of forestry in land-use planning.
Forest management may seem to be one activity among many others; it is, however, an example of an undertaking combining many diverse activities, from the forest to the processing of products. If it is limited to the forest and its logging, its coherence with other projects, particularly with forest industry projects, must be carefully checked. In addition - and this is what has often not been done sufficiently in the past - all the different possibilities and the corresponding costs and benefits must be subjected to economic analysis. All these considerations are very close to those that lead to the "combines" in countries with a centrally planned economy, where forests and their managers, the teams that harvest them and the industries that use their products constitute a single enterprise. One should provide, however, for flexibility and for mechanisms to enable such combines to adapt themselves better to a market economy. It is important to underline here that logging should be seen as a tool in the regeneration and enrichment of a stand, and that industries must make an effort to absorb most of the species available, grouped by final uses.
Whatever solutions are adopted, and bearing in mind the ecological, economic and social conditions, forest management should be conceived as the entire complex of management, utilization and processing and its development as the integrated development of these activities. These are in fact subsystems of a single system, even if standard hierarchic models of these subsystems are not yet available. A forest policy must therefore be defined that sets out the objectives of management, utilization and processing and the main lines of the actions to be undertaken to achieve them; this policy should be embodied in five to ten-year plans or programmes within the framework of the national plan; and, finally, each plan should be translated into a set of consistent projects, where the goals to be attained, the time span necessary and the corresponding means are defined for each.
