Search

In 2014 Decree 14/018 laying down the rules for granting forest concessions to local communities, followed by Ministerial Order 0/25 on the same issue was published in the DRC. This paper aims to analyse the abovementioned legislation with respect to participatory ma nagement of forests. The explicit recognition of the duality of a customary de facto local community forest and a modern legal entity (concession) is an innovation. However, viewed from the perspective of the long-established habits within the country, the question remains whethe r these legal measures can be sufficient for ensuring the sustainable development of these community-held forested areas. Allowing community concessions up to 50,000 ha demonstrated a shift in the government policy away from the industrial timber cultivation model. However, an ar ea this size is much larger than the communities can monitor, particularly in the case of artisanal charcoal or wood exploitation. (Resume d'auteur)

This viewpoint paper presents a reaction to the article by Brandt et al. (2016). It highlights the complexities inherent to the attribution of deforestation impacts to policy interventions when using remote-sensing data. This critique argues that in the context of the Congo a suite of factors (i.e., population density in particular) other than those considered by Brandt et al. (e.g., type of forest, distance from roads and markets) play essential roles in determining the fates of forests. It also contends that care is needed when making decisions regarding which units will be included in the comparison group so that contextual factors and on-the-ground information are properly considered (e.g., when logging operations are inactive or when a concession is used for 'conservation' purposes). Finally, it proposes that a focus on an analysis of deforestation rates for a given level of timber production might be a metric that more accurately represents one aspect of the consequences of forest management, which should also consider the appraisal of trade-offs associated with a larger set of social, financial and ecological objectives.

Malaysia has been endowed with a beautiful tropical forest which provides various ecosystem services such as carbon dioxide absorption, water supply and soil stabilization to the community. It is also a timber source for wood-based industries generating RM22 billion in 2016. However, there are illegal encroachment activities in the forests causing the forests to be degraded as well as conversion of land use to agriculture. The enforcement activities carried out by the authorities have resulted in the degraded areas being reclaimed and the forest areas are being restored with planting of local species with commercial value. To date many degraded forest areas have been restored using different approaches. This paper aims at presenting Malaysia's experiences and initiatives in forest restoration and rehabilitation of degraded forests. These activities have created opportunities to improve the forest ecosystem. There are also many challenges need to be addressed in order the forest restoration and rehabilitation to be successful. These challenges will also be discussed.

While attention to logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arise from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are covering now a larger area than the so-called primary forests. The Tropical managed Forests Observatory (TmFO), a new network of permanent sample plots in logged forests, aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 536 pem1anent plots and about 1200 ha of forest inventories. In this paper we will present the main results generated by the network on the impact of logging on Carbon and timber recovery, as well as biodiversity changes in the Amazon basin and South East Asia.

Community forest management (CFM) is considered an alternative way to protect forests while providing income for smallholders. Since the mid-1990s, the number of CFM projects has rapidly increased in the Brazilian Amazon, although most of them still face several difficulties. In this paper, we discuss the obstacles to the financial viability of CFM in this region and propose some ways to overcome them. Based on evidence from five case studies, we assess the extent to which sustainable forest management for commercial timber production contributes to smallholder income. We show that harvesting timber only provides a limited cash income to smallholders, even though forest covers 80% of their landholding. Market access to timber is very uncertain and smallholder communities often fail to make a profit from their timber. Minimum remunerative public prices and support for timber marketing are thus needed. Simpler and more flexible procedures are required to reduce the high transaction costs of obtaining a permit and increase smallholder involvement in legal forest management for commercial purposes. Finally, a better assessment of timber potential in smallholder forest reserves through systematic inventories would be useful to avoid arousing false expectations.

The Forest Stewardship Council (FSCJ label is one of t he most robust and widely accepted standards aimed at assessing long-term sustainable forest management worldwide. Through audits, accredited certification bodies assess the level or conformity of a company's performance against the standard to grant or not the certificate on behalf of the FSC. In this paper, we assess the scope auditors have to shape the implementation of the FSC standard in Brazil. Our work is based on the analysis of certification bodies· rules and of 250 full assessment and annual audit reports covering the period 2005-2017. including native and plantations reports. All reports were publicly available on FSC database. The analysis was completed with interviews with key informants. We show that most indicators of the Brazilian FSC standard leave no scope for interpretation. However, companies are certified and re-certified with a significant number of minor non-conformance with social, legal and environmental indicators. We conclude that some indicators are too broad and need to be clarified. Also, conformity with some indicators depends on actions from governments. The development of new national standards is an opportunity to limit the risks of interpretation of indicators. The updating of standards is also an opportunity to clarify the role of public policies in respect of specific indicators. States wishing to promote FSC certification could seize this opportunity to identify what improvements are needed in the functioning of their institutions and public policies.

The greater part of the semi-deciduous moist forests of the Congo basin has been given to logging companies for exploitation. In the next decades, very few of these forests will remain intact. In this paper, we aimed to identify large-scale variations in the structure, composition and functioning of African moist forests that could serve as a baseline for both management and conservation purposes. Commercial forest inventory data were assembled for 49,711 0.5-ha plots, covering an area of more than six million hectares, crossing the borders of Cameroon, Central African Republic and Republic of Congo. Floristic composition was analyzed for a subset of 176 genera reliably identified in the field. Three key functional traits of tropical trees: regeneration guild, leaf phenology, and wood specific gravity, were collected at the species level from various sources, and assigned at the genus level. We first investigated the main variations in forest structure and composition, and identified seven forest types based on these variations. Differences in the percentage of pioneer and deciduous stems, and mean wood specific gravity were tested between forest types. Most of the study area was composed of a mosaic of the structural variations of the forests characterized by the occurrence of Celtis (Ulmaceae) species, which are mostly composed of frequent and abundant genera that formed the common floristic pool of the region. Secondary Musanga (Moraceae) forest is located in repeatedly disturbed areas, along roads and around main cities; mixed Manilkara (Sapotaceae) forest covers a huge area in the southern Central African Republic and in the northern Republic of Congo; and monodominant Gilbertiodendron (Fabaceae) forest is sparsely distributed along rivers. The contrasted structure, composition, and functioning of the forest types imply pronounced differences in population and ecosystem processes, and call for adapted management and conservation strategies.

Industrial forest concessions cover about 45 million hectares in Central Africa. This paper discusses the weaknesses of the current concession model and initiatives for helping it evolve; it then proposes a new type of concession, entitled 'Concessions 2.0', adapted to the future challenges presented by the overlapping among the rights and modes of the harvesting of multiple resources. This proposed model is based on four features: (i) mapping and recognition of the customary territories within and around the industrial concession, (ii) timber revenue sharing indexed on the extension of the customary territories and contractual management agreements within the communities, (iii) allowance of commercial exploitation of non-timber resources by entitled claimers under the supervision and/or in association with the concessionaire, and (iv) inclusive governance for the management of overlapping rights over the concession area. (Resume d'auteur)

Responding to pressure from international markets, environmental NGOs and donors, several logging companies in the Congo Basin have opted for voluntary certification schemes, such as the one proposed by the Forest Stewardship Council (FSC). The FSC scheme promotes forest management that is environmentally appropriate, economically viable and socially beneficial. The latter component, which is the focus of this paper, aims at the optimal integration of the local population in the forest management. We assess local organizations active around six FSC certified concessions in Cameroon and evaluate their legitimacy and effectiveness in building and maintaining a positive relationship between communities and logging companies. Results show that FSC certification plays a key role in the emergence of multi-stakeholder platforms that function as mechanisms of improved 'social exchange'. To some extent, such exchanges also contribute to less conflicting relations between logging companies and local communities, as well as reinforcing the social requirements of the forest law. Some shortcomings, however, remain, and we suggest logging companies should consider improving the balance of power between themselves and the communities, notably by reviewing the current top-down approach in establishing and managing discussion platforms.

Harvesting from common resources has been studied through experimental work in the laboratory and in the field. In this paper we report on a dynamic commons experiment, representing a forest, performed with different types of communities of resource users in Thailand and Colombia, as well as student participants. We find that all groups overharvest the resource in the first part of the experiment and that there is no statistical difference between the various types of groups. In the second part of the experiment, participants appropriate the common resource after one of three possible regulations is elected and implemented. There is less overharvesting after the rules are implemented, but there is a significant amount of rule breaking. The surprising finding is that Colombian villagers break the rules of the games more often than other groups, and even more so when they have more trust in members of the community. This observation can be explained by the distrust in externally proposed regulations due to the institutional and cultural context.

International audience; Government based Payments for Ecosystem Services (PES) have been criticized for not maximizing environmental effectiveness through appropriate targeting, while instead prioritizing social side-objectives. In Mexico, existing literature on how the Payments for Ecosystem Services-Hydrological program (PSA-H) has targeted deforestation and forest degradation shows that both the process of identifying the eligible areas and the choice of the selection criteria for enrolling forest parcels have been under the influence of competing agendas. In the present paper we study the influence of the PSA-H multi-level governance on the environmental effectiveness of the program-the degree to which forest at high risk of deforestation is enrolled-building from a "policyscape" framework. In particular, we combine governance analysis with two distinct applications of the policyscape framework: First, at national level we assess the functional overlap between the PSA-H and other environmental and rural programs with regard to the risk of deforestation. Second, at regional level in the states of Chiapas and Yucatan, we describe the changing policy agenda and the role of technical intermediaries in defining the temporal spatialization of the PSA-H eligible and enrolled areas with regard to key socioeconomic criteria. We find that, although at national level the PSA-H program has been described as coping with both social and environmental indicators thanks to successful adaptive management, our analysis show that PSA-H is mainly found in communities where deforestation risk is low and in combination with other environmental programs (protected areas and forest management programs). Such inertia is reinforced at regional level as a result of the eligible areas' characteristics and the behaviour of technical intermediaries, which seek to minimise transaction costs and sources of uncertainty. Our project-specific analysis shows the importance of integrating the gover-nance of a program in the policyscape framework as a way to better systematize complex interactions at different spatial and institutional scales between policies and landscape characteristics.

In this paper we seek to identify the floristic determination biases contained in large-scale commercial inventories conducted by logging companies and to determine whether this impacts on the observed patterns of alpha and beta diversity. The study focused on floristic data recently collected by industrial timber companies in the tropical forests of the Central African Republic (28,229 0.5-ha plots spread over 14,000 km2). A subset of these plots (n = 1107) was later re-sampled for controlling purposes by experienced botanists. The proportion of agreement between the two samplings was assessed for each species and independently for small and large trees, and at genus and family resolutions. Unsurprisingly, large trees and common species were more accurately identified than small trees and rare species. We found that the quality of the floristic determination increased slightly from species to families. We also detected a significant variation between concessions in the quality of the floristic determination that was more dependent on working conditions during forest inventories than on field workers. Contrary to a widespread belief, we did not find a strong bias toward commercial species, showing that commercial inventory data could also be valid for non-commercial species in ecological studies. Finally, we found that both alpha and beta diversity patterns in commercial inventories were highly consistent with those of the re-sampled inventory. This latter result shows that commercial inventories are well suited to detect large-scale patterns of floristic variation. Large-scale commercial inventories could thus play an important role in the identification of large-scale patterns in tropical tree diversity. This could enhance our ability to manage tropical forests by designing representative reserve networks and developing management plans that integrate diversity patterns at the landscape scale.

Reconciling conservation and livelihoods is a concern wherever forests are important in local people's lives. We plead for engaging these people in survey activities to clarify what is important to them, as a first step in conservation planning. This will help to address their priorities and gain their guidance and support for interventions. This paper presents the results of such a survey with the community of Kwerba in Mamberamo, a remote and little known part of Indonesian Papua. Views and priorities were explored through interviews, scoring exercises, community mapping and a field survey. Whereas small gardens provided most staple food, culture and livelihoods were linked to the forest. People scored primary forest highest for nearly all use categories. Primary forest was particularly highly valued as a source of construction materials, ornaments and rituals, and as a hunting place. We developed a list of the overall most important plants and animals. Many natural resources were used, but few were commercially exploited. The community had rules to control access to certain areas and resources. Taboos to restrict access to sacred places were also maintained. Our evaluation identified opportunities to achieve conservation outcomes jointly with the Kwerba people. In follow-up activities, the community presented local government with a land-use plan for their territory. The government recognized the value of our approach and requested training to implement it more widely in the region.

This paper introduces a simulation model focused on smallholder practices and labour management that is used to assess the long-term impacts of alternative landuses in the Amazon region. Our objective is not to provide a tool for decision-makers but rather to inform the debate on rural practices and their likely consequences on forests resources, income generation, and land-use trajectories. We discuss the advantages and limitations of forest management (FM) for timber and permanent field of annual crops (PFAC), based on conservation agriculture, and the way in which they constitute management options with potential to protect forests while improving smallholders' livelihoods. Our model shows that subcontracted sustainable FM for timber (logging operations outsourced) in legal reserves and PFAC are not miraculous solutions that allow smallholders to prosper while preserving their forests. However, the additional earnings originated from FM facilitate the family's installation phase, which is often a critical period. Since income from FM can help farmers cultivate productive crops and pastures, it improves resilience to hazards (sickness and accident) that are frequent in the Amazon. In addition, since PFAC is an intensification technique, it has positive effects but only when adopted after the installation phase. In that case, it provides some additional profits by recovering degraded pastures. Considering a scenario with hazard probability and where 50% of smallholders' lands have to be dedicated to forest protection, adopting FM and PFAC appears to be a win-win solution for smallholders.

Certification schemes have played an increasing role in global environmental governance. The Forest Stewardship Council (FSC) is emblematic of these new forms of private environmental governance based on market values. Although there have been many studies on the impacts of FSC, this remains a controversial issue. Drawing on a critical review of the methodologies used to date to assess the impacts of forest certification schemes, this paper identifies three challenges that evaluation scholars have to address in order to assess the FSC scheme in terms of environmental effectiveness: developing a point of reference to which certification measures must be compared; extending and contextualising the scope of the evaluation; and analyzing all effective management measures that contribute to obtaining the environmental result observed before examining the specific role of certification.

International audience; The success of long-term sustainable management of natural resources depends on local people’s support. Assessing local people’s attitudes, taking into account their needs, and respecting their opinions should become a management priority. In India, in the last 20 years, community needs and aspirations in forest management were handled through Joint Forest Management with varying degrees of success. Recently, the Forest Rights Act (2006) was passed to recognize and vest forest rights in forest dwelling communities. This major policy development is still in implementation, but little is known about how this devolution process will affect people’s attitudes toward forests. In this paper, we analyze associations between attitudes toward state controlled forests (Reserved Forests) and (i) awareness about the Forest Right Act, (ii) attitudes toward the State Forest Department, and (iii) participation in forest management groups of mostly tribal forest dwellers in the district of Kodagu (Karnataka). We collected information with a structured questionnaire among 247 villagers living under three different land tenure and management regimes: (1) private coffee plantations, (2) Reserved Forest, and (3) National Park. The results of the multivariate analyses show that people are more likely to appreciate Reserved Forests if they have more knowledge about the Forest Rights Act and if they have positive attitudes toward the State Forest Department. A sobering result in our sample is that participation in formal forest management groups is negatively associated to attitudes toward Reserved Forests, suggesting the Joint Forest Management model doesn’t necessarily help the transition from coercion to consent. Increasing local people awareness about their rights and improving their relations with the formal forest stewards remain priorities for sustainable forest management to emerge in India.

Multiple-use forest management (MFM) is widely considered a prime objective within the sustainable forest management paradigm. Multiple-use forest management systems are certainly a promising and potential answer for how to better integrate and accommodate all stakeholders interests in the forestry sector and how to conciliate timber production with other products and services of the producing forests. Although the conceptual and practical underpinnings of MFM in the tropics were laid out more than a decade ago, forest management systems are still dominated by selective logging, while other forest goods and services such as non-timber forest products, hydrological regulation, and carbon sequestration are still poorly considered as potential sources of income in management practices. Based on three regional assessments of practical experiences in MFM in the Amazon basin, Congo basin, and Southeast Asia, this paper presents the main factors limiting or promoting the implementation of such multiple-use forest management systems in the tropics. This assessment allows us to propose and discuss the main research priorities actions to promote multiple-use forest management systems in tropical rainforests. (Texte intégral)

Le changement climatique est un enjeu croissant pour la société. Pour affronter cet enjeu, des instruments innovants en matière de Politique Publique (PP) sont nécessaires mais émergent difficilement dans les sociétés. Le Programme de Paiement pour Service Environnementaux (PPSE), adopté dès 1996 au Costa Rica, constitue une innovation singulière en termes de d'instrument PP pour lutter contre déforestation. Cette communication analyse les conditions qui ont permises l'adoption rapide et de l'évolution de cette politique. Mobilisant un cadre d'analyse cognitif des PP sur la longue durée, nous montrons que 1) le PPSE constitue un changement cognitif de la vision de la foret, 2) son adoption correspond à un changement des coalitions de cause dominantes dans le système politiques de gestion des espaces ruraux forestiers, 3) que ce changement est induit par une redistribution des ressources résultantes de modifications des variables externes et internes au système. Cette analyse permet de discuter les hypothèses de changement des PP énoncés dans le cadre de l'ACF et de mettre en perspective les évolutions récentes du PPSE à l'aune des processus d'apprentissage et d'évolution des coalitions de cause.

The Brazilian Amazon is one of the world’s largest tropical forests. It supplies more than 80 % of Brazil’s timber production and makes this nation the second largest producer of tropical wood. The forestry sector is of major importance in terms of economic production and employment creation. However, the Brazilian Amazon is also known for its high deforestation rate and for its rather unsustainably managed timber resources, a fact which puts in the balance the long-term future of the forestry sector in the region. Since the mid- 1990s, with strong support from World Wildlife Fund (WWF), the number of tropical forests certified by the Forest Stewardship Council (FSC) has significantly increased. This is especially true for projects sponsored by large scale companies. The number of community- based forest management projects has also increased. Certification of community-based forest enterprises (CFEs) was initially a goal for the sponsors and community members. Certification is viewed as a way to reach alternative timber markets. In Brazil, the state of Acre has the highest concentration of CFEs certified by FSC. Most of them have been implemented with the support of environmental NGOs and public funds. Environmental NGOs strongly defend the advantages of certification for communities; however, in reality, this option is not that advantageous. Despite all the efforts, the number of participants in each project remains low. Why is this occurring? In this paper, we analyze the underlying motives of a few individual’s participation in CFEs certification projects. We aim to present and discuss some factors that shape the success of CFEs and their later certification. The results are based on surveys conducted in two certified CFEs in the state of Acre., L’Amazonie Brésilienne, l’un des plus grands massifs forestiers mondiaux, est à l’origine de 80 % de la production de bois du Brésil. Les taux de déforestation élevés (malgré un certain ralentissement ces dernières années) et le rythme d’exploitation peu durable des ressources remettent en cause la pérennité du secteur forestier dans la région. Depuis le début des années 1990, avec le soutien du WWF, le nombre d’entreprises forestières certifiées par le FSC (Forest Stewardship Council) a considérablement augmenté dans le domaine privé. C’est aussi le cas, mais dans une très moindre mesure, de l’exploitation forestière communautaire, en particulier dans l’Etat de l’Acre. Les ONGs défendent de manière générale les multiples avantages de ce type de certification pour les communautés vivant en Amazonie. Pourtant, en dépit des multiples incitations financées à fonds perdus, le taux d’adhésion des communautés locales reste faible. Cet article analyse les facteurs responsables de la faible participation des populations aux projets de certification de l’exploitation communautaire des forêts. L’analyse est basée sur des enquêtes de terrains menées au sein de deux communautés forestières de l’Etat de l’Acre certifiées par le FSC.

International audience; Rural people in developing countries including India continue to access a number of types of 'forests' to meet specific needs such as fuelwood, fodder, food, non-timber forest produce and timber for both subsistence and income generation. While a plethora of terms exist to describe the types of forests that rural people use—such as farm forests, social forests, community forests and small-scale for-ests—the expression domestic forest has recently been proposed. Domestic forest is a term aimed at capturing the diversity of forests transformed and managed by rural communities and a way to introduce a new scientific domain that recognises that production and conservation can be reconciled and that local communities can be effective managers. This paper argues in the context of the central Western Ghats of south India that while the domestic forest concept is a useful umbrella term to capture the diversity of forests used by rural people, these domestic forests are often not autonomous local forests but sites of contestation between local actors and the state forest bureaucracy. Hence, a paradigm shift within the forest bureaucracy will only occur if the scientific forestry community questions its own normative views on forest management and sees forest policy as a means to recognise local claims and support existing practices of forest dependent communities.

International audience; The relationship between tropical forests and global climate change has so far focused on mitigation, while much less emphasis has been placed on how management activities may help forest ecosystems adapt to this change. This paper discusses how tropical forestry practices can contribute to maintaining or enhancing the adaptive capacity of natural and planted forests to global climate change and considers challenges and opportunities for the integration of tropical forest management in broader climate change adaptation. In addition to the use of reduced impact logging to maintain ecosystem integrity, other approaches may be needed, such as fire prevention and management, as well as specific silvicultural options aimed at facilitating genetic adaptation. In the case of planted forests, the normally higher intensity of management (with respect to natural forest) offers additional opportunities for implementing adaptation measures, at both industrial and smallholder levels. Although the integration in forest management of measures aimed at enhancing adaptation to climate change may not involve substantial additional effort with respect to current practice, little action appears to have been taken to date. Tropical foresters and forest-dependent communities appear not to appreciate the risks posed by climate change and, for those who are aware of them, practical guidance on how to respond is largely non-existent. The extent to which forestry research and national policies will promote and adopt management practices in order to assist production forests adapt to climate change is currently uncertain. Mainstreaming adaptation into national development and planning programs may represent an initial step towards the incorporation of climate change considerations into tropical forestry.

Co-management of forest resources is a process of governance that enables all relevant stakeholders to participate in the decision-making processes. Illegal logging and forest degradation are currently increasing, and logging bans are ineffective in reducing forest degradation. At the same time interest in forest plantations and concern about poverty problems of neighboring people whose livelihoods depend on forest services and products continue to increase rapidly. Governments have identified the development of small forest plantations as an opportunity to provide wood supplies to forest industries and to reduce poverty. However, the development of small plantations is very slow due to an imbalance of power and suspicion between communities and large companies. This paper proposes a framework for linking social, economic and biophysical dynamics to create multi-agent simulations and explore scenarios of collaboration for plantations. Multi-agent simulation is a branch of artificial intelligence that offers a promising approach to dealing with multi-stakeholder management systems, such as common pool resources. It provides a framework which allows analysis of stakeholders' (or agents') interactions and decision making. Each stakeholder has explicit communication capacities, behaviors and rationales from which emerge specific actions. The purpose of this modeling is to create a common dynamic representation to facilitate negotiations for growing trees. A system of governance involving multi-stakeholders, especially local communities and wood based industries appearing to offer the most promising pathway to accelerating plantation development, local community poverty alleviation and forest landscape improvement. © 2005 Elsevier Ltd. All rights reserved.

National audience; In order to predict the evolution of forest stands, and thus to facilitate forest management, researchers have developed different types of models of stand dynamics. In this paper, we illustrate the interest of such models as management tools. We consider three applications : (i) in a pure, even-aged oak stand, the use of a model in order to take into account the effect of productivity changes on growth ; (ii) in mixed, uneven-aged stands of spruce and fir, the comparison through simulation of a classical thinning to a thinning with openings ; (iii) in large-scale areas, the modelling of the dynamics of species composition of mixed stands. We finally discuss the limitations of models and future perspectives for research in this field.; Pour prédire l'évolution des peuplements forestiers, et ainsi faciliter l'aménagement, les chercheurs ont mis au point différents types de modèles de dynamique forestière. Dans cet article, nous illustrons l'intérêt de ces modèles comme outils pour la gestion. Nous présentons 3 applications : (i) dans un peuplement régulier de chênes, l'utilisation d'un modèle pour prendre en compte l'effet d'un changement de productivité sur la croissance ; (ii) dans un peuplement mélangé irrégulier épicéas - sapins, la comparaison par simulation d'un scénario sylvicole classique et d'un scénario d'éclaircies par trouées ; (iii) à l'échelle d'un massif forestier, la modélisation de l'évolution de la composition de peuplements mélangés. Nous discutons ensuite des limites des modèles ainsi que des perspectives de recherche.

The recent development of individual based and spatially explicit models raises the question of how to simulate relevant initial states for these models, and more particularly how to simulate realistic spatial structures. This is especially true for forest stand modelling.In this paper, we first review briefly the main simple steps in the simulation of forest stands with realistic spatial structure : (i) spatial structure analysis and ecological interpretation, (ii) expert simulation through classical point processes and ad hoc values of the parameters, and (iii) precise fitting of a spatial structure model using L(r) and L12(r) functions as criterion. We illustrate the advantages and limits of these steps on a real forest stand in mixed Oak - Scots pine forest near Orléans (France).We then propose a specific method - a mimetic point process - in order to simulate spatial structures similar to real patterns. This point process is based on a generalised Gibbs process, whose global cost function directly depends on the difference between the real measured values of L(r) and L12(r) functions, and the corresponding values computed on the simulated pattern at each iteration of the algorithm. We applied this method on a mixed Oak - Scots pine forest stand, and thus obtained an improved simulated pattern, that can be used as initial state for individual based forest growth models.We finally discuss the limits of this method, and its possible, Le développement récent des modèles individus-centrés spatialement explicites pose de nouvelles questions sur les méthodes de simulation des états initiaux de ces modèles, et plus particulièrement : comment simuler des structure spatiales réalistes. C'est tout particulièrement vrai pour les modèles forestiers. Dans cet article, nous proposons tout d'abord une revue bibliographique des principales méthodes de simulation de peuplements forestiers : (i) l'analyse et l'interprétation écologique de la structure spatiale, (ii) la simulation par expertise, et (iii) l'ajustement de modèles de structure spatiale en utilisant les fonctions L(r) et L12(r) comme critère d'ajustement. Nous illustrons les avantages et les limites de ces méthodes sur un dispositif expérimental en forêt mélangée Chêne - Pin sylvestre dans la forêt d'Orléans.Nous proposons ensuite une méthode spécifique - un processus mimétique - pour simuler des structures spatiales similaires à des structures réelles. Ce processus est basé sur un processus de Gibbs généralisé dont la fonction de coût total dépend directement de la distance entre les valeurs réelles des fonctions L(r) et L12(r) et les valeurs simulées à chaque itération de l'algorithme. Nous avons appliqué cette méthode sur un peuplement mélangé Chêne - Pin sylvestre, et avons obtenu un peuplement simulé plus réaliste, qui peut être utilisé comme état initial pour un modèle forestier individus-centré.Nous discutons enfin des limites de cette méthode, et de son intérêt pour faciliter le transfert des modèles vers les gestionnaires forestiers.

The conservation potential of managed production tropical forests has helped spur the development and implementation of timber harvesting practices generally referred to as 'low-impact' or 'reducedimpact' logging (RIL). These techniques are now widely recognised as an essential component of sustainable timber harvesting prescriptions. Numerous studies in the three major tropical forest biomes (Latin America, Central Africa, South East Asia) have demonstrated that, under moderate logging intensity, these techniques can reduce by 50% the damage on residual stand and soil. However, RIL operations are still based, as all other selective logging systems operated in the tropics, on a very simple rule: the minimum diameter limit (MDCL) applied to all commercial species. In very highly stocked forests such as mixed dipterocarp forests of SE Asia, this MDCL rule leads to high felling intensities (10-15 trees/ha). Field experiments carried out by CiradForêt from 1989 to 1996 and by CIFOR since 1997 in East Kalimantan showed that under such high felling intensities, logging damage rate by RIL and unplanned logging are comparable (> 50% of the remaining tree population). The long-term consequence of such high damage rates is an increase of the rotation cycle (> 80 years) for recovery, and important changes in species density, structure and composition. As such, a minimum diameter cutting limit approach only is seldom compatible with sustainable forest management. This paper presents how RIL techniques could be improved by applying simple complementary rules. These are: (1) integration of reduced-impact logging practices into normal management operations; (2) limiting the cut to 8 or less trees/ha (with a felling cycle of 40 to 60 years to be determined according to local conditions); (3) defining minimum diameter cutting limits according to the structure, density and diameter at reproduction of target species; (4) avoiding harvesting species with less than I adult tree/ha (dbh = 50 cm over an area of 50-100 ha); (5) minimizing the size and connectivity of gaps (

The main challenge for forest managers is to define the optimal rotation period able to ensure resource sustainability on a long-term basis. For this purpose, Cirad-Forêt developed three types of forest dynamics models: a density-dependent matrix model, a hybrid model (matrix / single-tree distance-independent) and a single-tree spatial model. These models were built based on records from the experimental site of Paracou in French Guiana, where Cirad-Forêt has monitored the growth, survival and mortality of trees since 1984, None of those models has proved efficient enough to properly assess the requirements of forest managers as far as the future of particular valuable species are concerned. Simple matrix models, as those used in several forest concessions of central Africa, could bring quick answers to the managers. In this paper, we calibrate such models for the three most harvested species in French Guiana; assess the impact of the uncertainty of the input parameters on the predictions and give some advice on the proper use of this method. Finally, we show the relevance of examining separately the fate of different species, as species groups can hide endangered individual situations.

The present paper contains proposals for genetic criteria and indicators which can form part of a more general set of, economic, environmental and social criteria and indicators for the monitoring of forest sustainability at the scale of forest management units. These proposals are intended for use in guiding tropical forest management, but because of the complexity of tropical forests, it is not possible to prescribe a uniform set of indicators for all circumstances. The pattern of genetic diversity that has already evolved is due to a balance of several evolutionary forces that operate at different spatial and temporal scales and forest practices would therefore be expected to affect several genetic factors. To provide guidance on what genetic processes may be affected by forest practices, we therefore first describe the genetic processes, then the forest practices that are expected to affect genetic processes, and we provide a matrix of relationships between types of forest practices and indicators of genetic processes. Since the intention of criteria and indicators is to steer and gradually improve forest management actions, the report identifies two main concerns of sustainability: first, whether a previous or a proposed practice poses substantial risk to genetic adaptability and second, what conservation or enhancement measures can be effective to mitigate any adverse impacts. We propose one criterion for conservation of forest genetic resources and four indicators related to processes that maintain genetic diversity. For each indicator, sets of verifiers are suggested which differ in the biologically relevant features they measure, in their precision, and in technical facilities they require. Finally, the need for rapid assessment and precision under difficult field conditions requires research and development of efficient direct and surrogate measures of the genetic resource. We therefore include recommendations for short- and medium term research that would improve the scientific value, costeffectiveness, ease of use, and further development of genetic criteria and indicators.

In Cameroon, local community involvement in the process of forest management is obligatory. Within the specific context of the Tropenbos Cameroon Programme, an approach has been developed to achieve this. After a varied phase of awareness-raising, the principal users of a 42,500 ha ecosystem were brought together to discuss the uses to which this forest land would be put, and its boundaries. It is this experience, from the initial negotiating conditions to the final result, which is described in this paper. It shows how a strategic group of local stakeholders was able to force players at the macro-level to comply with its point of view concerning the management of the forest. In order to avoid increased competition for both land and resources, an integrated mode of forest management is proposed, which goes beyond the administrative distinction between permanent and non-permanent forest estate.

These proceedings describe the experimental basis and preliminary results of the CIFOR project Site Management and Productivity in Tropical Plantations. The papers they contain were presented at the second workshop of project partners held in Pietermaritzburg, South Africa, in February 1998. This research, which is underway at 17 sites in seven countries and involves scientists from 16 institutions, focuses on inter-rotation management. This phase between tree harvesting and replanting for the next rotation is a window of considerable risks as well as opportunities. It holds the potential for physical and chemical soil degradation, but also offers a chance to remedy past mistakes and introduce sound technology for improved long-term management of plantation soils. Although the species and the soil problems vary according to local conditions, all the experiments have been designed to provide knowledge that will benefit both the specific sites and our understanding of underlying processes of tree productivity.

Building a forest road network is an important task for the forest manager Such a road network must be designed to minimize both the cost of construction and the operational cost. To find optimal locations for the road network, many forest engineers still use traditional methods that are almost entirely manual. Several attempts have been made already on the use of GIS for forest road network optimization in Indonesia and elsewhere. This paper deals with the evaluation and comparison of several methods and the research of the most efficient one for forest management purpose. We consider that a network is optimal if the cost of the construction is minimal. More specifically, the aim of our research conducted for a tropical forest concession in Central Africa (1.500 ha), is to plan an optimal forest road network to access logging areas, taking into account topographical and hydrographical constraints (slopes, swamps, wide rivers). Following Setyabudi (1994) and Dean (1997), an automated method is applied using IDRISI, a raster based Geographical Information System. Three methods are investigated, all of them based on the same principle of calculating a cumulative distance cost (Eastman, 1995) and applying a Pathway Analysis. In the simplest way, logging areas are considered as independent, unlike the second one for which an iterative process is used: the network is then built step by step. The lost method is more sophisticated which takes into account the nodes of the network (number and location). Finally results generated by these three methods are assessed in term of cost and compared to manual delineation.

This paper deals with the problem of road network building to access forest resources. In the literature, this problem is known as the multiple target access problem (MTAP). It can be formalized as follows: given a set of targets (the trees to harvest), a source (an existing forest road) and a cost surface (the road building cost), what is the cheapest network that connects all targets to the source? We propose two heuristic methods to solve big-sized MTAPs and we compare them to existing literature methods. Heuristics are compared on the basis of (i) the cost of the network that connects the targets to the source and (ii) of the computation time required by each heuristic. Results are obtained on a theorical example from the Maunga Whau volcano (Auckland volcanic field, New Zealand) and from a Monte Carlo experimental plan using randomly generated MTAP.