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Partie III - Mediterranean forest-based solutions. Chapter 12; International audience

In forestry, the variable of interest is not always directly available from forest inventories. Consequently, practitioners have to rely on models to obtain predictions of this variable of interest. This context leads to hybrid inference, which is based on both the probability design and the model. Unfortunately, the current analytical hybrid estimators for the variance of the point estimator are mainly based on linear or nonlinear models and their use is limited when the model reaches a high level of complexity. An alternative consists of using a variance estimator based on resampling methods (Rubin, D. B. (1987). Multiple imputation for nonresponse surveys. John Wiley & Sons, Hoboken, New Jersey, USA). However, it turns out that a parametric bootstrap (BS) estimator of the variance can be biased in contexts of hybrid inference. In this study, we designed and tested a corrected BS estimator for the variance of the point estimator, which can easily be implemented as long as all of the stochastic components of the model can be properly simulated. Like previous estimators, this corrected variance estimator also makes it possible to distinguish the contribution of the sampling and the model to the variance of the point estimator. The results of three simulation studies of increasing complexity showed no evidence of bias for this corrected variance estimator, which clearly outperformed the BS variance estimator used in previous studies. Since the implementation of this corrected variance estimator is not much more complicated, we recommend its use in contexts of hybrid inference based on complex models. -- Keywords : Estimator bias; Variance estimator; Estimate of the total; Horvitz-Thompson estimator; Log grade; Lumber recovery model.

The objective of this thesis is to predict the structural parameters of forests on a large scale using remote sensing images. The approach is to extend the accuracy of LIDAR full waveforms, on a larger area covered by polarimetric and interferometric (PolInSAR) synthetic aperture radar images using machine learning methods. From the analysis of the geometric properties of the PolInSAR coherence shape, we proposed a set of parameters that are likely to have a strong correlation with the LIDAR density profiles on forest lands. These features were used as input data for SVM techniques, neural networks, and random forests, in order to learn a set of forest descriptors deduced from LIDAR: the canopy height, the vertical profile type, and the canopy cover. The application of these techniques to airborne data over boreal forests in Sweden and Canada, and the evaluation of their accuracy, demonstrate the relevance of the method. This approach can be soon be adapted for future satellite missions dedicated to the forest: Biomass, Tandem-L and NiSAR.; Ce travail de thèse a pour objectif la prédiction des paramètres structurels des forêts à grande échelle, grâce aux images de télédétection. La démarche consiste à étendre la précision des données LIDAR spatiales, en les utilisant là où elles sont disponibles, en tant que donnée d'apprentissage pour les images radar à synthèse d'ouverture polarimétriques et interférométrique (PolInSAR). A partir de l'analyse des propriétés géométriques de la forme de cohérence PolInSAR, nous avons proposé un ensemble de paramètres susceptibles d'avoir une corrélation forte avec les profils de densité LIDAR en milieu forestier. Cette description a été utilisée comme données d'entrée de techniques SVM, de réseaux de neurones, et de forêts aléatoires, afin d'apprendre un ensemble de descripteurs de forêts issus du LIDAR : la hauteur totale, le type de profil vertical, et la couverture horizontale. L'application de ces techniques à des données réelles aéroportées de forêts boréales en Suède et au Canada, et l'évaluation de leur précision, démontrent la pertinence de la méthode. Celle-ci préfigure les traitements qui pourront être appliqués à l'échelle planétaires aux futures missions satellites dédiées à la forêt : Biomass, Tandem-L et NiSAR.

Les chercheurs en écologie du paysage essaient de comprendre l’effet de la structure et de la composition des habitats sur les espèces. La technologie LiDAR est encore peu utilisée dans ce domaine mais fournit des données précises sur de grandes zones. Nous cherchons ici à évaluer l’apport des données LiDAR en milieu forestier. La but est de voir si des métriques LiDAR pertinentes peuvent être extraites afin d’expliquer et prédire des indicateurs de biodiversité. Les résultats obtenus à partir de modèles linéaires généralisés (GLM) permettent d’expliquer entre 14 et 63% des variables de biodiversité étudiées (Indice de Biodiversité Potentielle, taux de prédation des défoliateurs, indice de consommation du chevreuil, richesse de la strate herbacée, richesse de différentes catégories d’oiseaux) à partir d’une combinaison d’une quinzaine de variables LiDAR. Dans un second temps, nous explorons l’apport de données LiDAR pour extraire automatiquement les cimes et couronnes des arbres. L’analyse est effectuée par extraction des maximas locaux ou par l’utilisation de la méthode de ligne de partage des eaux, sur le modèle numérique de hauteur issu des données LiDAR. Les algorithmes ont été testés sur une zone d’étude simplifiée présentant des arbres alignés avec un écart assez fixe. Il en ressort que la détection des cimes d’arbres est, dans ce cas d’étude, précise après un filtrage gaussien 3*3 du raster analysé. Les résultats obtenus demandent à être confirmés en raison du faible nombre d’observations. Cette étude ouvre toutefois des perspectives intéressantes sur l’apport du LiDAR en écologie., Landscape ecology researchers are trying to understand the effect of habitat structure and composition on species. LiDAR technology is still not widely used in this domain but provides accurate data over large areas. In this report, we try to assess the contribution of LiDAR data in forest environments. The aim is to see if relevant LiDAR metrics can be extracted to explain and predict biodiversity indicators. The results obtained from generalized linear models (GLM) allow to explain between 14 and 63% of the biodiversity variables studied (Potential Biodiversity Index, defoliator predation rate, deer consumption index, richness of the herbaceous stratum, richness of different categories of birds) from a combination of about fifteen LiDAR variables. In a second step, we explore the contribution of LiDAR data to automatically extract treetops and crowns from trees. The analysis is carried out by extracting local maxima or by using the watershed method on the digital height model derived from LiDAR data. The algorithms were tested on a simplified study area with trees aligned with a rather fixed gap. It appears that the detection of tree tops is, in this case of study, accurate after a 3*3 Gaussian filtering of the raster analyzed. The results obtained need to be confirmed due to the low number of observations. However, this study opens interesting perspectives on LiDAR’s contribution to ecology.

Made available in DSpace on 2015-03-18T15:56:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-01Bitstream added on 2015-03-18T16:28:25Z : No. of bitstreams: 1 WOS000339989900001.pdf: 614110 bytes, checksum: f2c6e46a0e535382a989dfebeb2bd5c0 (MD5) FFEM (Fonds Francais pour l'Environnement Mondial) Small-scale farmers in the Brazilian Amazon collectively hold tenure over more than 12 million ha of permanent forest reserves, as required by the Forest Code. The trade-off between forest conservation and other land uses entails opportunity costs for them and for the country, which have not been sufficiently studied. We assessed the potential income generated by multiple use forest management for farmers and compared it to the income potentially derived from six other agricultural land uses. Income from the forest was from (i) logging, carried out by a logging company in partnership with farmers' associations; and (ii) harvesting the seeds of Carapa guianensis (local name andiroba) for the production of oil. We then compared the income generated by multiple-use forest management with the income from different types of agrarian systems. According to our calculations in this study, the mean annual economic benefits from multiple forest use are the same as the least productive agrarian system, but only 25% of the annual income generated by the most productive system. Although the income generated by logging may be considered low when calculated on an annual basis and compared to incomes generated by agriculture, the one-time payment after logging is significant (US$5,800 to US$33,508) and could be used to implement more intensive and productive cropping systems such as planting black pepper. The income from forest management could also be used to establish permanent fields in deforested areas for highly productive annual crops using conservation agriculture techniques. These techniques are alternatives to the traditional land use based on periodic clearing of the forest. Nevertheless, the shift in current practices towards adoption of more sustainable conservation agriculture techniques will also require the technical and legal support of the State to help small farmers apply these alternatives, which aim to integrate forest management in sustainable agricultural production systems. Cirad Ctr Int Cooperat Rech Agron Dev, UR B&SEF Biens & Serv Ecosyst Forestiers Trop, F-34398 Montpellier 5, France Gret, BR-66055050 Belem, Para, Brazil UNESP, Fac Ciencas Agr, BR-18610307 Botucatu, SP, Brazil EMBRAPA, Amazonia Oriental, BR-66095100 Belem, Para, Brazil Serv Florestal Brasileiro MMA SFB, BR-68010200 Santarem, Para, Brazil UNESP, Fac Ciencas Agr, BR-18610307 Botucatu, SP, Brazil

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.

Public concerns about the environmental credentials of timber products have led to the introduction of procurement policies that add criteria other than price into the decision-making process. This demand-driven initiative alongside the importance of European markets for timber exports have prompted Cameroon to sign a Forest Law Enforcement, Governance and Trade Voluntary Partnership Agreement (FLEGT/VPA) with the European Union. This paper reviews the impacts of this policy. Firstly, the institutional arrangement for timber production is presented with special focus on various legal forms of forest exploitation. Secondly, the estimated costs for the required development and control of various types of forest management are presented. Finally the impacts of the FLEGT/VPA on forest governance, forest management, timber trade and socio-economic and development issues is explored. The positive impact of the agreement will be especially felt by industrial forest concession holders that harvest timber products for exports to international markets, but it will hardly be the case of community forests. However, the implementation of the agreement will engender huge financial costs for forest managers and national governments. Also, the livelihoods of small-scale loggers (who are the main suppliers of national markets) may be adversely affected by the procurement policies.

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.

The objective of this thesis is to predict the structural parameters of forests on a large scale using remote sensing images. The approach is to extend the accuracy of LIDAR full waveforms, on a larger area covered by polarimetric and interferometric (PolInSAR) synthetic aperture radar images using machine learning methods. From the analysis of the geometric properties of the PolInSAR coherence shape, we proposed a set of parameters that are likely to have a strong correlation with the LIDAR density profiles on forest lands. These features were used as input data for SVM techniques, neural networks, and random forests, in order to learn a set of forest descriptors deduced from LIDAR: the canopy height, the vertical profile type, and the canopy cover. The application of these techniques to airborne data over boreal forests in Sweden and Canada, and the evaluation of their accuracy, demonstrate the relevance of the method. This approach can be soon be adapted for future satellite missions dedicated to the forest: Biomass, Tandem-L and NiSAR., Ce travail de thèse a pour objectif la prédiction des paramètres structurels des forêts à grande échelle, grâce aux images de télédétection. La démarche consiste à étendre la précision des données LIDAR spatiales, en les utilisant là où elles sont disponibles, en tant que donnée d'apprentissage pour les images radar à synthèse d'ouverture polarimétriques et interférométrique (PolInSAR). A partir de l'analyse des propriétés géométriques de la forme de cohérence PolInSAR, nous avons proposé un ensemble de paramètres susceptibles d'avoir une corrélation forte avec les profils de densité LIDAR en milieu forestier. Cette description a été utilisée comme données d'entrée de techniques SVM, de réseaux de neurones, et de forêts aléatoires, afin d'apprendre un ensemble de descripteurs de forêts issus du LIDAR : la hauteur totale, le type de profil vertical, et la couverture horizontale. L'application de ces techniques à des données réelles aéroportées de forêts boréales en Suède et au Canada, et l'évaluation de leur précision, démontrent la pertinence de la méthode. Celle-ci préfigure les traitements qui pourront être appliqués à l'échelle planétaires aux futures missions satellites dédiées à la forêt : Biomass, Tandem-L et NiSAR.

Key message Short-rotation forestry using eucalyptus in degraded oak forests in the semi-arid area of NW Morocco can be a useful strategy to avoid further degradation and carbon loss from this ecosystem, but it might be constrained by nutrient and water supply in the long term.[br/] Context Land degradation and deforestation of natural forests are serious issues worldwide, potentially leading to altered land use and carbon storage capacity.[br/] Aims Our objectives were to investigate if short-rotation plantations can restore carbon pools of degraded soils, without altering soil fertility.[br/] Methods Carbon and nutrient pools in above- and below-ground biomass and soils were assessed using stand inventories, harvested biomass values, allometric relationships and selective sampling for chemical analyses.[br/] Results Carbon pools in the total ecosystem were low in the degraded land and in croplands (6–13 Mg ha−1) and high in forests (66–94 in eucalyptus plantations; 86–126 in native forests). The soil nutrient status of eucalyptus stands was intermediate between degraded land and native forests and increased over time after eucalyptus introduction. All harvest scenarios for eucalyptus are likely to impoverish the soil but, for the moment, the soil nutrient status has not been affected.[br/] Conclusion Afforestation of degraded land with eucalyptus can be a useful restoration tool relative to carbon storage and soil fertility, provided that non-intensive forestry is applied.

The recent development of operational small unmanned aerial systems (UASs) opens the door for their extensive use in forest mapping, as both the spatial and temporal resolution of UAS imagery better suit local-scale investigation than traditional remote sensing tools.Along with this rising use of drones, dense three-dimensional reconstruction through the combined use of photogrammetry and textit{Structure from Motion} techniques enables now the fine modelization of the canopy surface relief from a set of overlapping images.Forest management is evolving and has to cope with numerous news demands.A sustainable managemnent practice requires beforehand up-to-date and comprehenvise forest inventory.Traditionnal forest ressources inventories are carried out on the field.They are expensive and focus only on an sample of the forest.Information is delivered at the stand level, and specific measurements for individual tree is missing.The use of mapping drones can potentially changes the story by describing forest ecosystems on a tree-level.This thesis aims at investigating the use of unmanned aerial systems for the characterization of temperate forests (in Wallonia, Belgium).Modelization of the vegetation heigth also is investigated by the combinaison of photogrammetric canopy surface measurements with digital terrain elevation acquired by LiDAR.Eventually, the study of a time series of 20 drone fligths through the growing season enables to determine when is the optimal period for automatic classification of deciduous species.Photogrammetric measurements of individual deciduous tree heigth are always less accurate than high density LiDAR measurements (RMSE of 1.04 m versus 0.83 m for the latter).Nevertheless, the versatility of drones is far higher than LiDAR data, with the possibility of flying at the appropriate time and delivering both spectral and 3D information with a very high resolution.Spetral information is relevant among other for tree species identification.The optimal phenology state for the discrimination of deciduous species was demonstrated to be the end of leaf flush.The intra-species phenology is indeed well synchronized during this time windows ranging from late spring to early summer.A global classification error of 16% is reached by using single date UAS imagery, and multitemporal UAS acquisitions still improve the process of species discrimination.Altough precision forestry can largely benefits from UAS technology, legislation constraints limit the operationnal use of drones.Thus, UAS flights are most of the time restricted under a specific altitude and within a certain distance from the remote pilot.These constraints are sub-optimal for the mapping of forest, which requires beyond line of sigth fligth at relatively high altitude.We thus believe that the drone technology will be more developped for scientific investigations at a local scale (dozens or hundreds of hectares) than for forest inventory of large forest estate (thousands of hectares), Une gestion raisonnée et multifonctionnelle des forêts n'est possible qu'avec une description à jour de l'état de la ressource naturelle.Les inventaires forestiers traditionnels, réalisés sur le terrain, sont couteux et ne couvrent qu'un échantillonnage de la surface boisée.L'essor des drones civils pour la cartographie a initié une révolution dans le domaine de la télédétection environnementale.La polyvalence et la diversité des systèmes drones sont une aubaine pour la foresterie de précision.Ceux-ci sont utilisé pour la réalisation de cartographie très fine des habitats naturels avec une résolution temporelle et spatiale sans précédent.Nous explorons les possibilités d’utilisation de mini-drones pour la caractérisation quantitative et qualitative de la ressource forestière.Nous nous intéressons en particulier à l’estimation de la hauteur des arbres et à la caractérisation de la composition spécifique au sein de peuplements forestiers.La hauteur de la canopée est une variable dendrométrique de première importance : elle est un bon indicateur du stade de développement des peuplements et intervient notamment dans les estimations de biomasse ou de niveau de productivité.La composition spécifique est une information essentielle en regard des principales fonctions que remplit la forêt (conservation, production, récréation, etc).Nous avons comparé l'estimation de la hauteur des peuplements à partir de mesures LiDAR et celles obtenues par photogrammétrie.Bien que permettant une mesure de hauteur individuelle avec une incertitude de l'ordre de 1.04 m (RMSE) en feuillus, la photogrammétrie par drone sur des zones forestières est systématiquement moins précise que les mesures par LiDAR (RMSE de 0.83 m).Néanmoins, la grande flexibilité que confère les petits drones permet d'acquérir, au moment propice du stade de végétation, et l'information de relief de la canopée, et l'information spectrale.La période de fin de feuillaison, au début du mois de juin, s'est avéré le moment le plus propice à une discrimination automatique de cinq groupes d'essences feuillues (le chênes pédonculé, les bouleaux, l'érable sycomore, le frêne commun et les peupliers).Une erreur globale de classification des houppiers de 16% est obtenue avec des acquisitions monotemporelles, alors que l'utilisation d'imageries acquises à différentes dates permet encore d'améliorer cette classification.Les contraintes de la législation régissant l'utilisation des aéronefs sans pilote à bord restreignent le champs d'action des drones civils.Ainsi, les opérations avec un drone sont limitées sous un seuil d'altitude et à une distance maximale du télépilote, ce qui ne permet pas une utilisation optimale de cette technologie pour la couverture de grands domaines forestiers (plusieurs milliers d'hectares).C'est pourquoi nous pensons que les drones resterons un outils d'analyse de petites surfaces (dizaines voire centaines d'hectares), plus utiles à des fins de recherches scientifiques qu'à une utilisation en gestion forestière

La relation internormative entre le droit de l’Union européenne et le droit français en matière de protection de la biodiversité semble plutôt positive. Le droit français, en adéquation avec les dispositions européennes, intègre ses objectifs à l’échelon national. Dans une perspective plus théorique, la France s’intéresse aux notions et concepts émergents peu saisis par le droit mais proposés par l’Union européenne afin de mieux les comprendre et les exploiter par la suite. C’est l’exemple type des « services écosystémiques ». Toutefois, il demeure également la question délicate de l’application du droit. Car si la volonté de transposition textuelle est évidente, les instances de contrôle et les contrôles effectifs d’application du droit sont en revanche plus discrets, ce qui vient atténuer le dynamisme du mécanisme de transposition The internormative relationship between European Law and French Law in the field of biodiversity conservation seems positive. French law is consistent with European measures and integrates its provisions at national level. In a more theoretical perspective, France takes into account new concepts proposed by European Law, in order to use them in the future. This is for instance the concept of “ecosystem services”. However, it remains delicate problem of law implementation. Whether a textual transposition exists between France and European Union, supervisory bodies and controls for the application of Law remains rare. This reduce the dynamism observed for the transposition for the European Law in French Law.

Cette étude s’intéresse à l’industrie de la construction navale pour le milieu du XVIIIe siècle en France dans la région de Bayonne. L’objectif est de documenter la relation qu’entretiennent les pratiques de construction traditionnelles et innovatrices à cette période. L’architecture de la frégate le Machault est au cœur de cette analyse. Construit en 1757 à Bayonne et perdu en 1760, le Machault a été fouillé, documenté et parallèlement récupéré par les archéologues de Parcs Canada entre 1969 et 1972 à Ristigouche dans la baie des Chaleurs, Québec. Cette étude constitue la première analyse architecturale approfondie menée sur ces vestiges. L’analyse est réalisée en trois temps qui correspondent aux trois grandes étapes de la chaine opératoire de la construction du navire. Tout d’abord, il est question d’aborder l’aspect de la foresterie afin de saisir la nature de la ressource forestière mobilisée pour la construction de la frégate. Ensuite, ce mémoire se penche sur la conception architecturale des navires qui renvoie à un aspect plus théorique, car il relève de la façon dont les formes du navire ont été « pensées ». Enfin, la charpenterie est abordée afin de saisir la séquence d’assemblage du navire. Ensemble, ces trois grands aspects dressent un portrait général de la construction navale pour la région de Bayonne au milieu du XVIIIe siècle., This study addresses the shipbuilding industry for the middle of the eighteenth century in France in the region of Bayonne. It aims to document the relation between the regional shipbuilding tradition and a globalisation of naval techniques, as this period has been interpreted as one of abrupt change. The Machault, a French frigate built in Bayonne in 1757 and lost in Chaleur Bay, Québec, in the context of the Seven Years War en 1760 will be the object of this study. The archaeological analysis of the frigate gave us a unique vision of the eighteenth century shipbuilding industry. The analysis is organised in three main parts. First, the aspect of forestry will be addressed in order to understand the nature of the timbers resources that were used to build the frigate. Then, the thesis looks at the architectural design of the ship, based on theoretical considerations that reveal the ways of designing a ship. Finally, the carpentry will be analysed to dissect the assembly sequence of the ship, so as to analyse the construction itself. Together, these three main aspects will draw a portrait of the shipbuilding industry for the region of Bayonne in the mid-eighteenth century.

In this paper we construct a general principal-agent model to discuss voluntary subsidiesto a forest owner to increase the rotation period in a situation with asymmetric information aboutthe owner´s cost type. It is shown that for the forest owner with low cost the voluntary subsidy shallbe based on differences in the objective functions between the principal and the agent. However, foran owner with high costs the subsidy shall also include an incentive cost to secure correct revelationof the owner´s cost type. The general model is used to study various forest owner objectives such asmaximization of the value of timber, maximization of the social welfare and maximization of a mixbetween the timber value and the social welfare. With welfare maximization there is no differencein the objective functions between the regulator and the forest owner so no contract is necessary.We also investigate the implications of regulator uncertainty about the forest owner payoff. Bothwhen the regulator perceives a wrong objective function for the forest owner and when regulator isuncertain about the objective function of the owner, uncertainty may imply a lower welfarecompared to a situation with full certainty about the forest owners goal.

Forest loss has been considered in recent decades not only as an environmental concern to the local communities who depend on natural resources, but also at the national level as a possible loss of future sustainable development potential and as a contributor to national greenhouse gas emissions. Aside from emissions from land use change, deforestation can also cause damage to agriculture and infrastructure and contribute to an increased frequency of flash floods, landslides and consequent d...

The global demand for wood is rising and projected to increase by between 1.3 % and 1.8 % up to 2030. This increased demand can only be satisfied by plantation forests and the challenge is to intensify the productivity of such forests in a sustainable and resilient manner. This means using our best understanding of forest ecosystems to design management systems that ensure the long-term productivity of the forests and their ability to survive shocks caused by damaging events. In this paper we discuss the potential risks to plantation forests from abiotic hazards such as wind, drought, and fire and how these are likely to change with increasing intensification. We then discuss how these risks can be mitigated through choice of species and changes in management. In particular the paper will focus on the impact of using mixed species and mixed structure forests on risk and the potential benefits and disadvantages of such a management approach.

Reforms implemented to improve forest sector governance in Central Africa have yielded mixed results. There cannot be effective market-based sector regulation without the strict enforcement of a regulatory framework and a neutral administration. To improve governance, it would be more clear-sighted to abandon the postulate of a "neutral and benevolent State" and to support the emergence of institutionalized checks-and-balances within and on the side of government institutions.

The main objective of this paper is to investigate the impact of experience on the choice of visits to forests in a stated discrete choice experiment. Recent literature has indicated that experiences with the environmental services valuated may increase the respondents' certainty in their choice of hypothetical alternatives. We apply two indicators of experiences: the number of visits and the number of different forests visited during the last year. Applying the generalized multinomial logit model, we find that an increase in the number of visits to forests makes respondents' choices more predictable. However, the number of different forests visited reduces the predictability of choices. Furthermore, we investigate the relationship between respondents' experience of forest recreation and the self-reported choice certainty, controlling for respondents' social-demographics and other design characteristics. Finally, we show that self-reported choice certainty is positive correlated with the scale factor, as expected.

The transfer of energy and water, as well as gaseous components, in the soil–plant–atmosphere system plays a crucial role in many processes involved in climate change. The surface energy balance drives both evapotranspiration (closely linked to the CO2 flux) and sensible heat flux. By providing direct information on heat dissipation efficiency, surface temperature appears to be a key variable. In particular, a lot of work has been conducted on estimating evapotranspiration from thermal infrared (TIR) remote sensing measurements, in order to derive information relevant to agriculture (monitoring plant growth, detection of water stress, crop yield forecasting, etc.) or hydrology (water cycle monitoring, catchment water budget, etc.). This chapter first very succinctly presents the relationship between surface temperature and the surface energy balance, providing the reader with reference publications for further reading. This is followed by a review of the data available in the thermal infrared (TIR) domain and an analysis of various sources of uncertainty affecting surface temperature measurements and their impact on the final accuracy. The different methods for estimating and spatializing actual evapotranspiration (AET) are then discussed. Finally, practical applications of TIR information other than AET are briefly mentioned.

Given the importance of anthropogenic determinants in forest ecosystems within Europe, the objective of this paper is to link the evidence arising from biological models to socio-economic determinants, where the expected returns of forest investments represent the main driver. A micro-economic area allocation module is therefore coupled with an inventory-based forest dynamics module and a partial-equilibrium market module in a national-level forest sector model for France (FFSM++). Running long-term scenarios (until 2100), we show the implication of an active management policy on forest composition: when the most profitable option drives forest investments, coniferous forests are generally preferred over broadleaved ones. This result is, however, reappraised when the risk aversion of forest owners is explicitly considered in the model, given the higher risk associated with the former. We further show the strong stability of forest ecosystems that, due to the very long cycles, undergoes very small variations in volume stocks, even in scenarios where the initial forest regeneration is strongly influenced.

Objectives (1) To quantify the contribution of the French forest-wood product chain in terms of carbon sequestration and substitution when accounting for both the physical impacts (shifts in tree growth and mortality rates) and the market impacts (increased demand of harvested wood products (HWP)) of climate change (cc) and the subsequent forest managers adaptations; (2) To assess the uncertainty of the impacts on the above carbon balance and on forest allocation; and (3) To assess the role of managers’ expectations toward these future, uncertain but highly anticipated, impacts. Methodology We used a bio-economic model of the French Forest Sector (FFSM++) that is able to consider and integrate: (a) the effects of climate change over forest dynamics; (b) forest investment decisions (among groups of species) according to expected profitability; and (c) market effects in terms of regionalised supply, consumption and trade of HWP, depending on the forest resource stocks and international prices. By including both forest dynamics and forest products, we can evaluate the carbon balance taking the following elements into consideration: (a) carbon sequestered in live and dead biomass in the forest; (b) carbon sequestered in HWP; (c) carbon substituted when wood is used in place of fossil fuels or more energy-intensive materials; and (d) carbon released by forest operations. Results When the model is run at constant conditions for the next century, the average carbon potential of French forests is 66.2–125.3 Mt CO 2 y −1 , depending on whether we consider only inventoried wood resources, HWP pools and direct energy substitution, or if we also account for the carbon stored in tree branches and roots and if we consider the more indirect, but also largely more subjective, material substitution. These values correspond to 18.3% and 34.7%, respectively, of the French 2010 emissions (361 Mt CO 2 ). However, when we consider both the probable increment of coniferous mortality and changes in forest growth, plus the rise in HWP demand worldwide, the average sequestration rate of the French forest decreases by 6.6–5.8% to 61.8–118.0 Mt CO 2 y −1 . Running partial scenarios, we can assess the relative interplay of these two factors, where the price factor increases the HWP stock while decreasing the forest stocks (where the latter effect prevails), while the physical impact of climate change reduces both, but to a lesser extent. Considering short-sighted forest managers, whose behaviour is based uniquely on the observed conditions at the time decisions are made, we obtain a limited effect of the overall carbon balance but a relatively large impact on the area allocation of broadleaved vs. coniferous species.

Document de travail : Cahier du LEF - Hors-série n°5; Le bois est la principale richesse marchande issue de la forêt. Il alimente une filière large et complexe. Il est donc primordial de pouvoir assurer le suivi de cette ressource, notamment en termes de prix. De nombreuses initiatives existent depuis le XIXème siècle. Le Laboratoire d’économie forestière (LEF) se propose de dresser un panorama des principales sources d’information en matière de prix des bois. Cet éclairage devrait permettre au lecteur de mieux cerner les différences entre les indicateurs disponibles pour en améliorer l’utilisation.

Water plays a central role in plant biology and the efficiency of water transport throughout the plant affects both photosynthetic rate and growth, an influence that scales up deterministically to the productivity of terrestrial ecosystems. Moreover, hydraulic traits mediate the ways in which plants interact with their abiotic and biotic environment. At landscape to global scale, plant hydraulic traits are important in describing the function of ecological communities and ecosystems. Plant hydraulics is increasingly recognized as a central hub within a network by which plant biology is connected to palaeobiology, agronomy, climatology, forestry, community and ecosystem ecology and earth-system science. Such grand challenges as anticipating and mitigating the impacts of climate change, and improving the security and sustainability of our food supply rely on our fundamental knowledge of how water behaves in the cells, tissues, organs, bodies and diverse communities of plants. A workshop, 'Emerging Frontiers in Plant Hydraulics' supported by the National Science Foundation, was held in Washington DC, 2015 to promote open discussion of new ideas, controversies regarding measurements and analyses, and especially, the potential for expansion of up-scaled and down-scaled inter-disciplinary research, and the strengthening of connections between plant hydraulic research, allied fields and global modelling efforts.

The diverse uses of forests for mitigation climate change and for production of energy biomass, andtheir potentially conflicting impacts, have been investigated by the forest sector modeling communi-ties for some years (e.g., Delacote and Lecocq, 2011; Delacote et al., 2013). This special issue presentssome new results provided by forest sector modeling in this area.

Focus on ecosystem services and increased availability of spatial dataset describing ecosystems have generated a large interest in ecosystem service mapping. Maps of ecosystem services make the spatial heterogeneity in supply of demand for ecosystem services evident and they may serve as important tools for management and spatially targeted policies. In the present study we develop an approach for mapping forest recreation service based on high-resolution data and explicitly accounting for the visitors’ choice of travel mode. The demand for forest recreation, including the demand for forest attributes is estimated, applying the travel cost method and using data from a web-based survey and from a GIS database describing forests and the access to forests. The approach is applied to data from a recent survey carried out in Lorraine. Compared to previous mappings of the economic value of forest recreation, the present study also accounts for visitors who are not going by car, i.e. we include people walking and biking to the forests. In Lorraine car-borne visitors represent only about half of the forest visitors. The results shows that the choice of travel mode depend on the access to forest, implying that the travel mode should be modelled as an endogenous variable in scenarios where access to forest changes. The proposed model framework allow for this.

La forêt privée, à cause de l’importance indiscutable de l’élément humain inhérent à ce mode de tenure, se trouve au confluent de différents univers conceptuels. Dans ce contexte, les acteurs forestiers, peu importe leur appartenance, se fixent pour objectif de transmettre ce qu’ils jugent être des informations, des opinions ou des connaissances de qualité afin de faciliter la communication des savoirs liés à la foresterie. Parmi les outils de communication utilisés pour rejoindre le propriétaire forestier québécois, le guide pratique semble avoir la cote. Nous avons procédé à une analyse qualitative du Guide terrain – saines pratiques d’aménagement en forêt privée afin de découvrir comment le forestier conçoit la forêt qu’il présente, décrit et explique dans ce guide. L’approche métaphorique proposée par Lakoff et Johnson (1985) a permis de mettre en lumière le contenu latent du discours. L’analyse thématique des métaphores relevées, combinée à l’examen de leur articulation entre elles, a permis de constater que la forêt est conceptualisée de façon à y encourager l’implication humaine. Non industrial private forests (NIPFs), because of the induscutable importance of the inherent human element in this type of forest tenure, stands at the confluence of different conceptual universes. In this context, forest actors, regardless of their affiliation, aim to convey what they consider quality informations, opinions or knowledge in a way that facilitates the communication between forestry stakeholders. Among the communication tools used to reach Quebec’s NIPFs landowners, the field guide seems fairly popular. We conducted a qualitative analysis of Guide terrain – saines pratiques d’aménagement en forêt privée to discover how forestry professionals conceive the forest they present, describe and explain in this guide. Lakoff and Johnson’s metaphorical approach (1985) has shed light on the latent content of the text. A thematic analysis of the metaphors discovered, combined with a review of their mutual articulation, showed that the forest is conceptualized in a way that fosters human involvement.

The current classification methods of land use in remote regions have two serious limitations. The first is the conceptual mixture between land uses and covers, which does not reflect the actual direct use of land. A second limitation is the absence of important uses such as tourism, aquaculture and mining, which impose significant pressures on fragile territories. This paper presents a land use classification method developed specifically for the region of Magellan in the extreme south of Chile. It is a land use classification wide and conceptually clear, which allows an effective determination of the range of land exploitations in Patagonia, determining which areas are used and which remain unused. The method is based entirely on a GIS and is a key input for improving land management. The analysis shows a high percentage of direct use, contrary to the existing pristine perception, which imposes significant challenges for current land management strategies. Los métodos de clasificación de usos del suelo en regiones remotas presentan dos serias limitaciones. La primera es la mixtura conceptual de usos con coberturas que no refleja el uso efectivo del territorio. Una segunda limitación es la ausencia de usos importantes como turismo, acuicultura y minería, que imponen importantes presiones sobre territorios frágiles. Este trabajo presenta un método para determinar los usos territoriales en la región de Magallanes en el extremo austral de Chile. Se trata de una clasificación de usos del suelo elaborada específicamente para este territorio, conceptualmente clara y amplia, que permite establecer el alcance efectivo de las explotaciones territoriales, determinando qué territorios son utilizados y cuales permanecen sin uso. El método está basado íntegramente en un SIG y constituye un insumo clave para mejorar la gestión territorial. El análisis refleja un alto porcentaje de uso directo, contrario a la percepción de pristinidad existente, lo que genera importantes desafíos para las actuales estrategias de gestión territorial. [fr] Les méthodes de classification de l’utilisation du sol dans les régions reculées présentent deux limitations graves. La première est le mélange conceptuel d’utilisations avec une couverture qui ne reflète pas l’utilisation réelle de la terre. Une seconde limite est l’absence d’usages importants tels que le tourisme, l’aquaculture et l’exploitation minière, qui imposent de fortes pressions sur les terres fragiles. Cet article présente une méthode pour déterminer l’utilisation des terres dans la région de Magallanes à l’extrême sud du Chili. Il s’agit d’une classification de l’utilisation des sols développée spécifiquement pour ce territoire, conceptuellement claire et large, qui permet de déterminer la portée effective des exploitations territoriales, identifier les zones utilisées et celles qui restent inutilisées. La méthode est basée entièrement sur un SIG et est un élément clé pour améliorer la gestion des terres. L’analyse montre un pourcentage élevé d’utilisation directe, contrairement à la perception de nature intacte existante, créant des défis importants pour les stratégies actuelles de gestion des terres.

The aim of the present work was to provide a synopsis of the scientific literature concerning the effects of different tree spe- cies on soil and to quantify the effect of common European temperate forest species on soil fertility. The scientific literature dealing with the tree species effect on soil has been reviewed. The composition of forest overstory has an impact on the chemical, physical and biolo- gical characteristics of soil. This impact was highest in the topsoil. Different tree species had significantly different effects on water ba- lance and microclimate. The physical characteristics of soils also were modified depending on the overstory species, probably through modifications of the soil fauna. The rates of organic matter mineralization and nitrification seem to be dependent on tree species. A coni- ferous species, Picea abies, had negative input-output budgets for some nutrients, such as Ca and Mg. This species promoted a higher soil acidification and a decrease in pH. Thus, it should not be planted in very poor soils in areas affected by acidic atmospheric deposi- tions. Nevertheless, the effect of the canopy species on soil fertility was rarely significant enough to promote forest decline. The impact of a tree species on soil fertility varied depending on the type of bedrock, climate and forest management. forest soils / tree species / fertility / sustainability / resiliency

Henry-Louis Duhamel du Monceau figures as an outstanding man of the age of enlightenment. Associate member then pensioner of the Académie Royale des Sciences de Paris, in the class of Botany, a great part of his work was devoted to the study of plants, especially to biology and physiology. He was in relationship with most of the scientists of his time. His books, characterized by a constant concern for pedagogy and a comparative analyse of experiences made by his colleagues, were of great importance and played significant part in disseminating knowledge of plant life., Savant injustement méconnu, Henry-Louis Duhamel du Monceau est l’une des figures scientifiques marquantes du Siècle des Lumières. Associé puis pensionnaire dans la classe de Botanique de l’Académie Royale des Sciences, il consacra une partie très importante de son travail au monde des plantes. Si sa longue vie scientifique est plus marquée par la physiologie végétale "pure" ou appliquée que par la botanique au sens strict du terme, il était très "au fait" des progrès de cette science et il a fréquenté tous les botanistes marquants de son temps. Ses ouvrages, caractérisés par la discussion approfondie des interprétations et par un souci constant de pédagogie, lui ont permis d’exercer un rôle de premier plan dans la diffusion et dans la progression des connaissances de l’époque., Hartmann Claude. Henry-Louis Duhamel du Monceau (1700-1782) et la Botanique. In: Le Journal de botanique, n°20, 2002. pp. 55-63.

- Two approaches of forest management, one in Europa and another in North America, apply to urban and suburban forests. In Europa the patterns which characterize the interaction between forests and towns are complex and are not always the cause of the decline of forest ecosystems (cf. examples of Bruxelles and Berlin). In North America, the contradiction between production and conservation forestry are close to the opposition between completely artificial urban forests (example of Québec) and ancient seminatural woods which exist near the town center (example natural park "Scarpe-Escaut" (North of France), from 1970 to nowadays, emphasized the new functions of suburban forests., Résumé. - En partant de deux conceptions de la forêt, l'une européenne, l'autre nord-américaine, peut-on mettre en évidence des modèles forestiers urbains et périurbains ? Dans les modèles européens, les relations ville-forêt ne sont pas uni- voques et ne vont pas toujours dans le sens d'une dégradation de la forêt (exemples de Bruxelles et de Berlin). Dans les modèles nord-américains, la dualité entre foresterie productiviste et foresterie écologiste se retrouve dans les modes de gestion de la forêt urbaine (exemples de Québec et de Montréal). L'évolution des conceptions et des pratiques de l'aménagement forestier au sein du parc naturel régional Scarpe-Escaut (Nord de la France), de 1970 à nos jours, atteste des «nouvelles fonctions» de la forêt proche de la ville., Dubois Jean-Jacques. Les forêts urbaines et péri-urbaines : des modèles à réinventer ? (Urban and suburban forests : new patterns ?). In: Bulletin de l'Association de géographes français, 77e année, 2000-2 ( juin). La nature en ville. L'eau dans les milieux arides et semi-arides (suite) sous la direction de Isabelle Roussel et Brigitte Coque. pp. 175-188.

Modelling plant structure and growth has undergone major changes in the last decades along two major lines: the integration of ecophysiological knowledge in process-based models which often lack a description of plant topology and geometry, and the generation of 3-D virtual plants using morphogenetic models which simulate the architectural development in a stable and homogeneous environment. There is now a trend to merge these two approaches, that is to link plant architecture and functioning. This trend is based on the recognition that plant structure: (i) is the joint output of the physiological processes (water and carbon balance, etc.) and the morphogenetic programme of the plant, (ii) determines the external environment of the trees which itself regulates their functioning (competition for space, light attenuation, etc.), and (iii) directly conditions the physiological processes within the tree (hydraulic structure, self shading, allocation of photosynthates, etc.). Such models can be used in agronomy and forestry in various ways: to investigate the effects, local and global, immediate and delayed, of the biophysical environment on plant morphogenesis and yield; to study light attenuation through the canopy, to analyse the transport of water and the allocation of photosynthates within the plant; to analyse the competitive interactions among different plants in the same stand; to calibrate remote sensing techniques and to visualize large landscapes. (Resume d'auteur)

Quantification of management measures and ecosystem service provision

The stated preference approach to costs of provision

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.

International audience; The analysis of point patterns often begins with a test of complete spatial randomness using summaries such as the emptyspace function F or the nearest neighbour distance distribution function G. These functions constitute basic summaries upon which many studies are based, depending on their shape. As the map of points is usually considered accurate, Monte Carlo tests are performed on the observed pattern without taking into account position errors. However, position errors usually occur during the mapping process. The aim of this article is to quantify the impact of measurement error on descriptive distance statistics and to integrate these errors in the non-parametric analysis. An application to tropical forest species is presented.

Dans l'État du Pará, 60 % des forêts destinées à l'aménagement sont des forêts paysannes. Les concessions forestières d'entreprise ne pourront fournir au mieux que la moitié de la consommation actuelle. À quelques exceptions près, les communautés traditionnelles et les familles paysannes n'ont ni l'expérience technique ni la capacité économique pour conduire l'exploitation commerciale des bois : l'aménagement est réalisé par le biais d'accords avec une entreprise, selon différentes modalités. Dans ce contexte, les contrats entre communautés et entreprise sont de nature très variée et aboutissent au contrôle total par les entreprises privées de toutes les opérations, du plan d'aménagement à l'exploitation. Les politiques publiques et la législation forestière cherchent aujourd'hui à améliorer les capacités des communautés locales à défendre leurs intérêts dans le cadre de tels partenariats. Cette étude analyse le cadre financier de l'entreprise par rapport à l'organisation paysanne pour son exécution, et les éléments clés qui permettent un meilleur contrôle : les inventaires pré- exploitation, la diversification de la production de bois d'oeuvre et de produits forestiers non ligneux, la commercialisation, le suivi et le contrôle des opérations d'exploitation. Il est proposé des pistes de politiques publiques qui doivent aider à la diffusion de l'aménagement paysan dans différentes contextes fonciers : unités de conservation et forêts de production, périmètres de colonisation agricole. L'article discute des modalités d'action et d'implantation d'un service public d'assistance technique et financière au profit des agriculteurs et des communautés. Le potentiel de l'intégration de la gestion forestière au sein des systèmes de production paysans est discuté dans le cadre du débat actuel de réforme du code forestier. (Résumé d'auteur)