Suchergebnisse

Herbicide use in forestry is analysed from an historical and environmental perspective. First chemical herbicides were developed during the Second World War. Organochloride herbicides were widely used in the past but they are now classified as very harmful for human and the environment. However, recently developed herbicides like glyphosate present the same efficiency and a much lower toxicity. In general, the public opinion about herbicides is strongly negative. In Québec, all herbicides were banned from use in public forest after some environmental assessments. This decision seems to be more politically than scientifically based. In the case of intensive managed forest, mechanical treatments with forest tractors can present similar or even lower environmental impacts than glyphosate, but few studies exist to make an objective comparison. Furthermore, in terms of tree growth, low toxicity herbicides seem to present higher effectiveness than mechanical treatments. This possible growth gain can then be used to reduce pressure on natural forest by increasing protected areas and the use of ecosystem forest management. Nevertheless, the use of herbicides must be strictly monitored to reduce environmental risks. ; La problématique de l'utilisation des herbicides en foresterie est analysée selon une perspective historique et environnementale. Le développement des herbicides chimiques remonte à la fin de la deuxième guerre mondiale. Les premiers herbicides organochlorés étaient très efficaces, mais ils sont aussi très toxiques pour l'humain et l'environnement. Les herbicides développés plus récemment, comme le glyphosate, sont tout aussi efficace et beaucoup moins toxiques, mais ils sont mal perçus par la population. Au Québec, l'utilisation de tous les herbicides en forêt publique fut prohibée suite à une évaluation environnementale rigoureuse. Il semble que la décision d'abolir son utilisation était plus politique que scientifique. En effet, une comparaison sommaire des impacts environnementaux possibles du glyphosate comparativement aux dégagements mécaniques manuels et mécanisés ne permet pas de dégager lequel des traitements est préférable au niveau strictement environnemental. Puisque certains herbicides permettent une meilleure croissance des plantations, il est possible d'imaginer que ce gain de croissance pourrait être utilisé pour augmenter les aires protégées et le niveau d'aménagement écosystémique sur une proportion plus grande du territoire. Néanmoins l'utilisation d'herbicides devrait être largement surveillée tant au niveau de l'application qu'au niveau du suivi environnemental.

It's easy to stand in awe of a city's impressive skyline, marveling at its buildings reaching for the clouds and its vast network of roadways and train lines crisscrossing in every direction. It can often seem like everything in a city is man-made, all concrete, steel, and glass. But even the asphalt jungle is not all asphalt-a sidewalk's cracks are filled with nature, if we know where and how to look. To aid us in this quest is Nature All Around Us, which will help us to recognize (and look after) the natural world we traipse through in our daily lives. Nature All Around Us uses the fam.

Unter dem Begriff der ˈMetaanalyseˈ werden Methoden systematischer und quantitativer Reviews zusammengefasst, welche objektive Aussagen zur Größe und Konsistenz eines untersuchten Effektes über die veröffentlichte Literatur zu ermöglichen. Mit meiner Dissertation trage ich die folgenden Hauptergebnisse zu dem, sich noch entwickelnden, Forschungsfeld der Metaanalyse von Zusammenhängen zwischen Baum-Diversität und Waldfunktionen bei: (i) Effekte der Baumdiversität auf Insektenherbivoren könnten sich entlang eines, bisher nicht berücksichtigten, globalen Gradienten ändern, (ii) artspezifische Mischungseffekte auf das Wachstum verschiedener Baumarten können (noch) nicht zwischen verschiedenen Forschungsansätzen übertragen werden und (iii) unter Berücksichtigung möglicher Korrelationsstrukturen kann die Schätzung fehlender Varianzwerte die Glaubwürdigkeit und Präzision von Metaanalyse-Ergebnissen erhöhen.

Unter dem Begriff der ˈMetaanalyseˈ werden Methoden systematischer und quantitativer Reviews zusammengefasst, welche objektive Aussagen zur Größe und Konsistenz eines untersuchten Effektes über die veröffentlichte Literatur zu ermöglichen. Mit meiner Dissertation trage ich die folgenden Hauptergebnisse zu dem, sich noch entwickelnden, Forschungsfeld der Metaanalyse von Zusammenhängen zwischen Baum-Diversität und Waldfunktionen bei: (i) Effekte der Baumdiversität auf Insektenherbivoren könnten sich entlang eines, bisher nicht berücksichtigten, globalen Gradienten ändern, (ii) artspezifische Mischungseffekte auf das Wachstum verschiedener Baumarten können (noch) nicht zwischen verschiedenen Forschungsansätzen übertragen werden und (iii) unter Berücksichtigung möglicher Korrelationsstrukturen kann die Schätzung fehlender Varianzwerte die Glaubwürdigkeit und Präzision von Metaanalyse-Ergebnissen erhöhen.

AbstractAlong with forest managers, builders are key change agents of forest ecosystems' structure and composition through the specification and use of wood products. New forest management approaches are being advocated to increase the resilience and adaptability of forests to climate change and other natural disturbances. Such approaches call for a diversification of our forests based on species' functional traits that will dramatically change the harvested species composition, volume, and output of our forested landscapes. This calls for the wood-building industry to adapt its ways of operating. Accordingly, we expand the evaluation of the ecological resilience of forest ecosystems based on functional diversification to include a trait-based approach to building with wood. This trait-based plant-building framework can illustrate how forecasted forest changes in the coming decades may impact and guide decisions about wood-building practices, policies, and specifications. We apply this approach using a fragmented rural landscape in temperate southeastern Canada. We link seven functional groups based on the ecological traits of tree species in the region to a similar functional grouping of building traits to characterize the push and pull of managing forests and wood buildings together. We relied on a process-based forest landscape model to simulate long-term forest dynamics and timber harvesting to evaluate how various novel management approaches will interact with the changing global environment to affect the forest-building relationships. Our results suggest that adopting a whole system, plant-building approach to forests and wood buildings, is key to enhancing forest ecological and timber construction industry resilience.

Assessing the perception of key stakeholders within the forest sector is critical to evaluating their readiness to engage in adapting to climate change. Here, we report the results of the most comprehensive survey carried out in the Canadian forestry sector to date regarding perceptions of climate change. A total of 1158 individuals, representing a wide range of stakeholders across the five most important forestry provinces in Canada, were asked about climate change, its impact on forest ecosystems, and the suitability of current forest management for addressing future impacts. Overall, we found that respondents were more concerned about climate change than the general population. More than 90% of respondents agreed with the anthropogenic origins of climate change, and > 50% considered it a direct threat to their welfare. Political view was the main driver of general beliefs about the causes of climate change and its future consequences, while the province of origin proved to be the best predictor of perceived current impacts on forest ecosystems and its associated risks; and type of stakeholder was the main driver of perceived need for adaptation. Industrial stakeholders were the most skeptical about the anthropogenic cause(s) of climate change (18% disagreed with this statement, compared to an average of 8% in the other stakeholders), its impacts on forest ecosystems (28% for industry vs. 10% for other respondents), and the need for new management practices (18% vs. 7%). Although the degree of awareness and the willingness to implement adaptive practices were high even for the most skeptical groups, our study identified priority sectors or areas for action when designing awareness campaigns. We suggest that the design of a strategic framework for implementing climate adaptation within the Canadian forest sector should focus on the relationship between climate change and changes in disturbance regimes, and above all on the economic consequences of these changes, but it should also take into account the positions shown by each of the actors in each province. ; This project was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) through a strategic grant 430393- 12. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

The world's forests and forestry sector are facing unprecedented biological, political, social, and climatic challenges. The development of appropriate, novel forest management and restoration approaches that adequately consider uncertainty and adaptability are hampered by a continuing focus on production of a few goods or objectives, strong control of forest structure and composition, and most importantly the absence of a global scientific framework and long‐term vision. Ecosystem‐based approaches represent a step in the right direction, but are limited in their ability to deal with the rapid pace of social, climatic, and environmental changes. We argue here that viewing forest ecosystems as complex adaptive system provides a better alternative for both production‐ and conservation‐oriented forests and forestry. We propose a set of broad principles and changes to increase the adaptive capacity of forests in the face of future uncertainties. These span from expanding the sustained‐yield, single‐good paradigm to developing policy incentives and interventions that promote self‐organization and integrated social‐ecological adaptation. ; This research was supported by the Marie Curie IRSES Newforests Project (EU‐FP7–612645).