22 research outputs found
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Geostatistical modeling of riparian forest microclimate and its implications for sampling
Les modÚles de prédiction du microclimat pour différentes conditions de station dans les zones riveraines boisées
des cours dâeau de tĂȘte de bassin sont peu dĂ©veloppĂ©s et les procĂ©dures dâĂ©chantillonnage pour caractĂ©riser les gradients
sous-jacents du microclimat riverain sont rares. Nous avons utilisé des données de microclimat riverain collectées le long de
huit cours dâeau de tĂȘte de bassin dans la chaĂźne cĂŽtiĂšre de lâOregon pour comparer le krigeage ordinaire (KO), le krigeage
universel (KU) et le krigeage avec dérive externe (KDE) pour la prédiction localisée de la température moyenne maximale
de lâair (Tair). Plusieurs caractĂ©ristiques topographiques et de la structure de la forĂȘt ont Ă©tĂ© considĂ©rĂ©es comme paramĂštres
spĂ©cifiques Ă la station. LâĂ©lĂ©vation au-dessus du cours dâeau et la distance du cours dâeau Ă©taient les covariables les plus
importantes dans les modĂšles de KDE qui donnaient de meilleurs rĂ©sultats que le KO et le KU en termes dâĂ©cart-type. La
répartition des échantillons a été optimisée sur la base de la variance de krigeage et des moyennes pondérées du critÚre de
la plus courte distance Ă lâaide dâun algorithme de recuit simulĂ©. La rĂ©partition optimisĂ©e des Ă©chantillons donnait de meilleurs
résultats que la répartition systématique en termes de variance moyenne de krigeage, surtout lorsque le nombre
dâĂ©chantillons Ă©tait faible. Ces rĂ©sultats suggĂšrent des mĂ©thodes pour augmenter lâefficacitĂ© du suivi du microclimat dans les
zones riveraines.Predictive models of microclimate under various site conditions in forested headwater stream â riparian areas are poorly developed, and sampling designs for characterizing underlying riparian microclimate gradients are sparse. We used riparian microclimate data collected at eight headwater streams in the Oregon Coast Range to compare ordinary kriging (OK), universal kriging (UK), and kriging with external drift (KED) for point prediction of mean maximum air temperature (T air). Several topographic and forest structure characteristics were considered as site-specific parameters. Height above stream and distance to stream were the most important covariates in the KED models, which outperformed OK and UK in terms of root mean square error. Sample patterns were optimized based on the kriging variance and the weighted means of shortest distance criterion using the simulated annealing algorithm. The optimized sample patterns outperformed systematic sample patterns in terms of mean kriging variance mainly for small sample sizes. These findings suggest methods for increasing efficiency of microclimate monitoring in riparian areas
The changing culture of silviculture
Changing climates are altering the structural and functional components of forest ecosystems at an unprecedented rate. Simultaneously, we are seeing a diversification of public expectations on the broader sustainable use of forest resources beyond timber production. As a result, the science and art of silviculture needs to adapt to these changing realities. In this piece, we argue that silviculturists are gradually shifting from the application of empirically derived silvicultural scenarios to new sets of approaches, methods and practices, a process that calls for broadening our conception of silviculture as a scientific discipline. We propose a holistic view of silviculture revolving around three key themes: observe, anticipate and adapt. In observe, we present how recent advances in remote sensing now enable silviculturists to observe forest structural, compositional and functional attributes in near-real-time, which in turn facilitates the deployment of efficient, targeted silvicultural measures in practice that are adapted to rapidly changing constraints. In anticipate, we highlight the importance of developing state-of-the-art models designed to take into account the effects of changing environmental conditions on forest growth and dynamics. In adapt, we discuss the need to provide spatially explicit guidance for the implementation of adaptive silvicultural actions that are efficient, cost-effective and socially acceptable. We conclude by presenting key steps towards the development of new tools and practical knowledge that will ensure meeting societal demands in rapidly changing environmental conditions. We classify these actions into three main categories: reexamining existing silvicultural trials to identify key stand attributes associated with the resistance and resilience of forests to multiple stressors, developing technological workflows and infrastructures to allow for continuous forest inventory updating frameworks, and implementing bold, innovative silvicultural trials in consultation with the relevant communities where a range of adaptive silvicultural strategies are tested. In this holistic perspective, silviculture can be defined as the science of observing forest condition and anticipating its development to apply tending and regeneration treatments adapted to a multiplicity of desired outcomes in rapidly changing realities
The changing culture of silviculture
Changing climates are altering the structural and functional components of forest ecosystems at an unprecedented rate. Simultaneously, we are seeing a diversification of public expectations on the broader sustainable use of forest resources beyond timber production. As a result, the science and art of silviculture needs to adapt to these changing realities. In this piece, we argue that silviculturists are gradually shifting from the application of empirically derived silvicultural scenarios to new sets of approaches, methods and practices, a process that calls for broadening our conception of silviculture as a scientific discipline. We propose a holistic view of silviculture revolving around three key themes: observe, anticipate and adapt. In observe, we present how recent advances in remote sensing now enable silviculturists to observe forest structural, compositional and functional attributes in near-real-time, which in turn facilitates the deployment of efficient, targeted silvicultural measures in practice that are adapted to rapidly changing constraints. In anticipate, we highlight the importance of developing state-of-the-art models designed to take into account the effects of changing environmental conditions on forest growth and dynamics. In adapt, we discuss the need to provide spatially explicit guidance for the implementation of adaptive silvicultural actions that are efficient, cost-effective and socially acceptable. We conclude by presenting key steps towards the development of new tools and practical knowledge that will ensure meeting societal demands in rapidly changing environmental conditions. We classify these actions into three main categories: re-examining existing silvicultural trials to identify key stand attributes associated with the resistance and resilience of forests to multiple stressors, developing technological workflows and infrastructures to allow for continuous forest inventory updating frameworks, and implementing bold, innovative silvicultural trials in consultation with the relevant communities where a range of adaptive silvicultural strategies are tested. In this holistic perspective, silviculture can be defined as the science of observing forest condition and anticipating its development to apply tending and regeneration treatments adapted to a multiplicity of desired outcomes in rapidly changing realities