Responsable
Osvaldo Valeria
Collaborateurs
Nicole J. Fenton, Philippe Marchand, Yves Bergeron, David Paré, Alain Leduc, Nelson Thiffault
Étudiants
Nicolas Mansuy, Christine Tatiana Corredor Durango
Problématique
La forêt boréale nordique présente plusieurs particularités qui nous obligent à repenser les stratégies sylvicoles habituellement retenues pour son aménagement. Se développant sous un climat souvent froid et humide, la couche humique des sols nordiques à tendance s’accumuler au fil du temps. Lorsque sévères, les feux de forêts réussissent à consumer cette couche organique et, par le fait, régénèrent la productivité originale. En comparaison, en protégeant les sols, la CPRS favorise l’accumulation de matière organique, diminuant ainsi la productivité des sols.
Objectifs
Développer des outils d’aide à la décision qui permettent de faire des choix éclairés quant aux contraintes et potentiels sylvicoles que présentent les sols de la forêt nordique.
Méthodologie
La production d’une carte de la vulnérabilité à l’entourbement ou à la paludification du sol à une échelle opérationnelle à 25m de résolution sur une superficie d'un peu plus de 20 000 km2 sera réalisée à l’aide des méthodes d’interpolation. Celle-ci sera élaborée à partir d’un jeu d’entraînement des placettes-échantillons temporaires du 3e et 4e inventaire décennal du MFFP, des mosaïques d'images de télédétection optiques (Landsat) et radar. La carte permettra de spatialiser régionalement les attributs de paludification au sein des peuplements forestiers les plus susceptibles à la paludification. En plus, une clé dichotomique basée sur les attributs issus de la cartographie du livrable concernant la paludification et les conditions du site et les attributs des peuplements forestiers sera élaborée. Cette clé permettra d’identifier la stratégie d’aménagement la plus plausible (par exemple, ne rien faire, coupe d’hiver, coupe d’été, CPI et autres). Cette clé mettra en valeur l’ensemble des outils sylvicoles disponibles le plus prometteurs pour contrer les effets de perte de productivité.
Retombées escomptées
Ce projet vise à développer une cartographie régionale du potentiel de paludification qui se veut dynamique dans le temps et à développer une clé décisionnelle des traitements sylvicoles adaptés aux caractéristiques des écosystèmes forestiers.
Applicabilité
Forêt boréale et nord du Québec
Livrables
Abdelghani Chehbouni, Yves Bergeron, Ahmed Laamrani, Osvaldo Valeria. Analysis of the E ect of ClimateWarming
on Paludification Processes: Will Soil Conditions
Limit the Adaptation of Northern Boreal Forests
to Climate Change? A Synthesis. 2020. Forests 11:1176
DOI : 10.3390/f11111176
Northern boreal forests are characterized by accumulation of accumulation of peat (e.g., known as paludification). The functioning of northern boreal forest species and their capacity to adapt to environmental changes appear to depend on soil conditions. Climate warming is expected to have particularly pronounced effects on paludified boreal ecosystems and can alter current forest species composition and adaptation by changing soil conditions such as moisture, temperature regimes, and soil respiration. In this paper, we review and synthesize results from various reported studies (i.e., 88 research articles cited hereafter) to assess the effects of climatic warming on soil conditions of paludified forests in North America. Predictions that global warming may increase the decomposition rate must be considered in combination with its impact on soil moisture, which appears to be a limiting factor. Local adaptation or acclimation to current climatic conditions is occurring in boreal forests, which is likely to be important for continued ecosystem stability in the context of climate change. The most commonly cited response of boreal forest species to global warming is a northward migration that tracks the climate and soil conditions (e.g., temperature and moisture) to which they are adapted. Yet, some constraints may influence this kind of adaptation, such as water availability, changes in fire regimes, decomposer adaptations, and the dynamic of peat accumulation. In this paper, as a study case, we examined an example of potential effects of climatic warming on future paludification changes in the eastern lowland region of Canada through three different combined hypothetical scenarios based on temperature and precipitation (e.g., unchanged, increase, or decrease). An increase scenario in precipitation will likely favor peat accumulation in boreal forest stands prone to paludification and facilitate forested peatland expansion into upland forest, while decreased or unchanged precipitation combined with an increase in temperature will probably favor succession of forested peatlands to upland boreal forests. Each of the three scenarios were discussed in this study, and consequent silvicultural treatment options were suggested for each scenario to cope with anticipated soil and species changes in the boreal forests. We concluded that, despite the fact boreal soils will not constrain adaptation of boreal forests, some consequences of climatic warming may reduce the ability of certain species to respond to natural disturbances such as pest and disease outbreaks, and extreme weather events. View Full-Text
Yves Bergeron, Luc Guindon, Nicolas Mansuy, André Beaudoin, Mohammed Henneb, Nicole J. Fenton, Ahmed Laamrani, Sonia Légaré, Osvaldo Valeria. Soil data for mapping paludification in black spruce forests of eastern Canada. 2018. Data in brief 21:2616-2621
DOI : 10.1016/j.dib.2018.11.131
Soil data and soil mapping are indispensable tools in sustainable forest management. In northern boreal ecosystems, paludification is defined as the accumulation of partially decomposed organic matter over saturated mineral soils, a process that reduces tree regeneration and forest growth. Given this negative effect on forest productivity, spatial prediction of paludification in black spruce stands is important in forest management. This paper provides a description of the soil database to predict organic layer thickness (OLT) as a proxy of paludification in northeastern Canada. The database contains 13,944 OLT measurements (in cm) and their respective GPS coordinates. We collected OLT measurements from georeferenced ground plots and transects from several previous projects. Despite the variety of sources, the sampling design for each dataset was similar, consisting of manual measurements of OLT with a hand probe. OLT measurements were variable across the study area, with a mean ± standard deviation of 21 ± 24?cm (ranging from a minimum of 0?cm to a maximum of 150?cm), and the distribution tended toward positive skewing, with a large number of low OLT values and fewer high OLT values. The dataset has been used to perform OLT mapping at 30-m resolution and predict the risk of paludification in northeastern Canada (Mansuy et al., 2018) [1]. The spatially explicit and continuous database is also available to support national and international efforts in digital soil mapping.
Luc Guindon, Yves Bergeron, Nicolas Mansuy, André Beaudoin, Nicole J. Fenton, Ahmed Laamrani, Sonia Légaré, Osvaldo Valeria. Digital mapping of paludification in soils under black spruce forests of eastern Canada. 2018. Geoderma 15:e00194
DOI : 10.1016/j.geodrs.2018.e00194
In northern boreal ecosystems, paludification is defined as the accumulation of partially decomposed organic matter over saturated mineral soils, a process that reduces tree regeneration and forest growth. Given this negative effect on forest productivity, spatial prediction of paludification in black spruce stands is important in forest management. Here, we used the Random Forest approach to predict organic layer thickness (OLT) as a proxy of paludification in northeastern Canada, where forests tend to paludify naturally. The RF approach involved regression and classification models using a suite of 20 environmental predictors derived from multiple sources. The performance of each model was evaluated using cross-validation and an independent dataset based on conventional ecological survey maps from a provincial forest inventory. Importance measures of the predictors indicated that slope, topographic position index, spectral bands 4 and 5 from Landsat, latitude, and PALSAR_HH were the most important variables explaining the spatial distribution of OLT for both models. Cross-validated relative root mean square error (± standard deviation) for the regression model was estimated at 20.66%?±?0.576, with R2 of 0.41?±?0.020, whereas the average out-of-bag error for the classification model was estimated at 44.75%. However, both models performed better in predicting high risk of paludification (OLT values >40?cm). With predicted OLT values averaging 44.07?±?16.80?cm (range 4.25–104.58?cm), the spatial patterns were in accordance with the results of previous studies at the national and landscape scale. These results highlight that ecological types such as black spruce–sphagnum on thin-to-thick organic deposit, with ombrotrophic drainage, are particularly prone to paludification (OLT depth?>?40?cm) throughout the study area. Limitations of the models and applications for decision-making in forest management are discussed.
Valeria, Osvaldo; Mansuy, Nicolas; Laamrani, Ahmed; Fenton, Nicole; Bergeron, Yves; 2016. Regional predictive mapping of paludification black spruce forests in the north eastern Canada using remote sensing and statistical modeling. Proceedings Book 7th edition of the International Scientific Conference ForestSAT 2016,1, 978-956-7459-49. Valeria, O*., Mansuy, N., Laamrani, A., Jaton, L., Fenton, N., Guindon, L., Bergeron, Y., Beaudoin, A. & S. Légaré. 2019. Cartographie prédictive régionale de la paludification dans les forêts d’épinettes noires de l’est du Canada à l’aide de la télédétection et d’une approche d’apprentissage automatique. 33e Congrès annuel de l’Association québécoise de spécialistes en sciences du sol (AQSSS), 11 au 14 juin, Duhamel-Ouest, Québec. Valeria O*., T. Corredor, P. Marchand, N. Mansuy, A. Laamrani, N. Fenton, A. Beaudoin and L. Guindon. 2018. Comparing predictive mapping of paludification in black spruce forests of eastern Canada. IBFRA 2018 «The International Boreal Forest Research Association » with IIASA, PEEX and IUFRO. "Cool Forests at Risk! The critical role of boreal and mountain ecosystems for people, bioeconomy and climate". La conférence aura lieu en Laxenburg, septembre 2018. Autriche. Winner coolest poster pitch! Valeria Osvaldo*, Nicolas Mansuy, Ahmed Laamrani, Lise Jaton, Luc Guindon et André Beaudoin. 2019. Using digital soil mapping tools to predict soil organic layer thickness in black spruce forests of eastern Canada. GDRI 'Cold Forests' Meeting 2019. Conference: 2019 I R Non Cold Forests Congress Duparquet At: Duparquet lake - FERLD- Canada. Mansuy, N. Valeria, O.* Laamrani, A. Fenton, N. Beaudoin, A. Guindon L. et Y. Bergeron 2016. Regional predictive mapping of paludification black spruce forests in the north eastern Canada using remote sensing and statistical modeling. ForestSAT- Santiago, Chile Nov 14-18, 2016. Mansuy N, Valeria O., Laamrani A. Fenton N. Beaudoin A. et Y. Bergeron 2016. Cartographie régionale de la paludification dans la pessière noire du nord-du-Québec à l’aide des méthodes de classification automatisés. 18e Colloque annuel de la Chaire industrielle CRSNG-UQATUQAM en aménagement forestier durable, Rouyn-Noranda, Québec, 2 décembre 2016.Valeria O., (Présentation orale)
Avancement
En cours
Organismes subventionnaires
MITACS, Programme d’innovation forestière – Centre canadien sur la fibre de bois, Coopérative, Plan Nord
Financement annuel
Financement terminé
Durée
2016-2022
Dernière mise à jour :
2022-04-03 07:35:22
