Foresterie | EPFL Graph Search

La foresterie est la science de gestion, de conservation, d'aménagement, et d'utilisation des forêts. En français québécois, ce terme est préféré à celui de sylviculture. Si les deux termes sont proches, lorsque la distinction est faite entre foresterie et sylviculture, la première discipline a un sens plus large que la seconde. Articles connexes *Foresterie analogue Notes et références Catégorie:Sylviculture

Analyse et exploitation des données de LIDAR aéroportés pour la caractérisation des milieux boisés de la Suisse

Gilles Gachet

Forest ecosystems show diverse and evolving structures. Accurate descriptions and a good knowledge of these environments are therefore a real challenge. Existing forest cover investigation methods are mostly laborious, hard to replicate and usually based on the skills of a small number of experts. Moreover, these methods are bound to standard two-dimensional information originated from aerial images or land surveys. The use of LiDAR elevation models leads to the development of new methodologies likely to propose innovative solutions to improve and ease the description and study of forests. In practice, managers often carry out maintenance forestry tasks as well as experimental ones. These tasks are successfully completed by means of tree observation and census. It is precisely with census that LiDAR technology can provide innovative solutions, allowing collection of accurate and reliable information from objects standing out of ground surface. Spatial analysis tools are then used to establish suitable indicators or cartographic documents to identify and define forest management objectives, to plan measures to achieve these goals, or even to monitor the results. The main objective of this PhD thesis is to propose new methods based on LiDAR technology applied to forestry. At first the study focuses on basic characteristics of a forest cover. Specific investigation of the potential of LiDAR elevation models to estimate the location, the height of individual trees and stands is carried out. In a second stage issues closer to management tasks are addressed, in particular analysis of horizontal and vertical structure of the forest, quantification of stock and identification of significant changes between two successive planting situations on the same site. Concerns of this study are to divert synthetic and normalized indicators in order to facilitate the actions and decision making process of the forester. It wants to extract innovative information in order to improve the knowledge and the description of wooden environments. A more or less significant participation of the skilled practitioner is required to configure the operations and to interpret the indicators, purpose of which is to save time by allowing more targeted and more complete ground investigation, subjective factor being in the benefit of the results. Although discussed issues as well as presented developments are based on common forest problems and of universal nature, they are presented in a context strongly influenced by Swiss forestry. The new contributions as well as the boundaries of the LiDAR technology are central to the reflection.

EPFL2009

Ecological response of tree saplings to simulated climate change along an elevational gradient (CLIMARBRE)

María Paula Sanginés De Cárcer

Switzerland will face higher temperature increases than the global average, which will have strong impacts on the mountain ecosystems. How tree species will respond to future climate change scenarios, and what mechanisms will they adopt, remains as a gap of knowledge in ecological research. Foresters will have to make short-term decisions and plan future managements under the great uncertainty of climate change and they demand answers to know if the current species will cope with the predicted climate change and to what extent the ecological goods and services will be affected (e.g. timber industry). The project CLIMARBRE was developed in order to ease and support their decision making by providing an advanced knowledge about the responses of beech and spruce regeneration to simulated climate change (specifically, warmer and drier conditions) in the wooded pastures of the Swiss Jura mountains. This project, which was built on the interface between fundamental research in forestry ecology and applied sciences, should attract the attention of foresters, managers of natural environments and of the general public. By using transplantation along an elevational gradient, in the Jura mountains, ârealisticâ climate conditions were created to specifically simulated three potential future climatic scenarios from the IPCC (from A1B to A2). This space for time approach enabled the assessment of saplingsâ responses to simulated climate change and their acclimation abilities. Saplings adapted to subalpine conditions at 1350 m were collected and transplanted towards lower altitudes exposing them to an average increase of 6.3áµC and a reduction in 30% of precipitation, at the lowest site throughout the study period. The main findings include i) a longer growing season due to induced-elevation warming (downward shift) could not fully account for the species-specific positive growth responses; (ii) the contrasting species growth responses were linked to different sensitivities to elevated vapor-pressure deficits; (iii) models could better account for the growth response to warming after incorporating extreme climatic events and their effects; iv) beech leaves showed an increase of xeromorphism through the increase of the cuticle thickness, vein network and smaller stomata, associated, to a higher leaf area v) which allowed it to grow in warmer conditions while coping with an increase of evaporative; vi) and finally, the linkage between responses at tree, leaf, tissue and soil level, through a multiple level approach, improved the mechanistic understanding of these species capacities to respond to simulated climate change.

EPFL2017

Flooding tolerance of Central European tree and shrub species

Rodolphe Schlaepfer

Extensive efforts have been made in recent years to restore rivers with a view to increasing the ecological value of riparian areas and the surrounding landscape and to improving the protection provided against extreme flooding events. One of the important factors for the successful establishment and survival of tree and shrub species in enlarged river corridors (particularly in lowlands) - and in retention basins - is their capacity to survive in anoxic conditions, i.e. their flooding tolerance. The importance of improving our understanding of flooding tolerance and the associated factors is underlined by the increasing interest shown in these issues by landscape planners and forestry services throughout Europe. Knowledge about the physiological and metabolic response of most Central European tree and shrub species is still incomplete. From a management perspective, there is a high level of interest in exploiting factors that incorporate these physiological and metabolic processes, but in ways that are easy to implement and to evaluate in the field. This paper presents a synthesis of knowledge available on the response of Central European tree and shrub species to flooding and highlights the main biotic and abiotic factors that influence species response. The modelling of the impact of flooding on plant species, the success of restoration projects, the planning of retention basins and even the estimation of the economic repercussions of flooding events on forestry could be improved through better knowledge of the flooding stress response of individual tree and shrub species arising from more systematic investigation. (c) 2006 Elsevier B.V. All rights reserved.