Frédérik Doyon

Contribution of Traditional Knowledge to Ecological Restoration: Practices and Applications

Abstract: Traditional knowledge has become a topic of considerable interest within the research and development environment. The contribution of traditional knowledge to conservation and management is increasingly recognized, and implementation endeavours are underway in several countries. The current scale of ecosystem degradation underscores the need for restoration interventions. It is increasingly recognized that successful ecological restoration depends on effective coordination of science and traditional ecological knowledge. This paper synthesizes the literature to evaluate the present and potential contribution of traditional knowledge to ecological restoration. Despite a growing number of articles published on traditional knowledge, only a few have addressed its contributions to ecological restoration per se. The main contributions of traditional knowledge to ecological restoration are in construction of reference ecosystems, particularly when historical information is not available; species selection for restoration plantations; site selection for restoration; knowledge about historical land management practices; management of invasive species; and post-restoration monitoring. Traditional knowledge and science are complementary and should be used in conjunction in ecological restoration projects. Incorporation of traditional knowledge can contribute to build a strong partnership for the successful implementation of restoration projects and increase their social acceptability, economical feasibility, and ecological viability.

Sustained Yield Forestry in Sweden and Russia: How Does it Correspond to Sustainable Forest Management Policy?

This paper analyzes how sustained yield (SY) forestry is defined and implemented in Sweden and Russia, two countries with different forest-industrial regimes. We first compare definitions of SY forestry in national legislation and policies. Then we study forest management planning in two large forest management units with respect to: delivered forest products and values, how the harvest level of timber is defined, where the harvest takes place, and what treatments are used to sustain desired forest products and values. In Sweden SY forestry is maximum yield based on high-input forest management, and in Russia it is forestry based on natural regeneration with minimum investments in silviculture. We conclude that how SY forestry contributes to SFM depends on the context. Finally, we discuss the consequences of SY forestry as performed in Sweden and Russia related to its ability to support diverse forest functions, as envisioned in sustainable forest management policy.

Tree productivity and successional status in Québec northern hardwoods

AbstractFew studies have sought to understand the growth characteristics of tree species in order to explain the observed patterns of succession. This study seeks to determine the successional stat...

Relationship between canopy disturbance history and current sapling density of Fagus grandifolia and Acer saccharum in a northern hardwood landscape

To shed light on the currently increasing proportion of Fagus grandifolia Ehrh. saplings in the tolerant hardwood forests of Quebec, we studied 48 Acer saccharum Marsh. dominated stands with contrasting histories of canopy disturbance: old commercial clear-cutting (CC), old fire (F), and either one or two partial cuts (1PC and 2PC). Our results indicated that higher densities of both F. grandifolia and A. saccharum saplings were associated with partial cutting histories (1PC and 2PC) than with severe canopy disturbance (CC and F). The density of F. grandifolia saplings was not related to any soil or stand characteristics in stands with a history of severe canopy disturbance. However, in stands with a history of partial canopy disturbances, the relative density of F. grandifolia saplings as compared with A. saccharum was related to soil C/N ratio and the presence of F. grandifolia overstory trees, whereas the absolute density showed a negative relationship with stand basal area. Therefore, it appears that ...

The successional status of sugar maple (Acer saccharum), revisited

Two complementary experimental designs at two contrasting scales (landscape/long term; individual tree/short term) were used for an in-depth evaluation of the successional status of sugar maple (AS: Acer saccharum Marsh.). First, forest disturbances during the 20th century and composition were mapped for two landscapes in the Du Lièvre watershed of southern Quebec. Our results show that, as well as dominating stands in the absence of fire, AS often rapidly developed dominance after fire, especially in the south of our study area. Similarly, a majority of AS-dominated stands clearcut in 1928 continued to be AS-dominated 60 years later. Second, we examined AS seedlings planted under two very contrasting light regimes. AS seedlings showed a combination of traits particularly adapted to tolerate shade under a low light regime. However, owing to a surprisingly high phenotypic plasticity, AS also exhibited efficient development under high light. This suggests the classification of AS as a late-successional species should indeed be revised and that generalist or trans-successional would be a more appropriate designation for this species. We discuss the ramifications of such a status revision, with an emphasis on the implications for its silviculture.RésuméDeux dispositifs expérimentaux complémentaires, établis à deux échelles différentes (paysage/long terme et individu/court terme), ont été utilisés afin de mieux évaluer le statut successionnel de l’érable à sucre (AS : Acer saccharum Marsh.). D’abord, une cartographie des perturbations et de la composition forestière au cours du 20e siècle a été réalisée pour deux paysages du bassin du Lièvre dans le Sud du Québec. Nos résultats ont démontré qu’en plus de dominer les peuplements en absence de perturbation du couvert, AS établissait souvent et rapidement une dominance dans les peuplements ayant brûlé, et cela, particulièrement dans le paysage le plus au sud de l’air d’étude. De la même façon, une majorité de peuplements dominés par AS et coupés à blanc en 1928 s’est révélée encore dominée par AS à peine 60 ans après coupe. Ensuite, en réalisant le suivi de semis plantés sous deux régimes lumineux très différents, AS a montré un ensemble de caractéristiques particulièrement adaptées à une bonne tolérance à l’ombre. Cependant, grâce à une étonnante plasticité phénotypique, AS a aussi démontré un développement compétitif sous des régimes lumineux plus élevés. L’ensemble de ces résultats suggère donc une remise en question du statut de fin de succession de AS, lequel répondrait mieux à une appellation d’espèce généraliste ou trans-successionnelle. Les implications d’une telle révision sur la sylviculture de cette essence sont discutées.

Canopy Gap Detection and Analysis with Airborne Laser Scanning

The opening and closure of “gaps” in forest canopies plays an important role in the structure, turnover, and overall ecological processes of natural forests. Gap characterization was until recently mostly based on field studies and relied on sampling approaches. ALS (Airborne Laser Scanning) has now revolutionized this field of scientific enquiry by giving researchers the capacity to detect and measure gaps rapidly over large areas. We first provide a brief scientific background on gaps and then succinctly review field and other conventional remote sensing methods to characterize them. We then turn our attention to the principles of ALS-based gap detection and review different methods of automated gap delineation and measurement. We explain how gap types can be automatically classified, and how multitemporal ALS can be used to not only monitor gap dynamics, but also to reveal the complex role of gaps in influencing tree growth within and around them.

Multi-Scale Segmentation of Forest Areas and Tree Detection in LiDAR Images by the Attentive Vision Method

A scale-adaptive method for object detection and LiDAR image segmentation in forest areas using the attentive vision approach to remote sensing image analysis is proposed. It provides an effective solution to the general task of object segmentation defined as the subdivision of image plan into multiple objects regions against the background region. This method represents a multi-scale analysis of LiDAR images by an attention operator at different scale ranges and for all pixel locations to detect feature points. Besides the initial height image, the operator also uses primitive feature maps (components) to reliably detect objects of interest such as individual trees or entire forest stands. As a result, feature points representing the optimal seed locations for region-growing segmentation are extracted and scale-adaptive region growing is applied at the seed locations. At the second level, the final segmentation by the scale-adaptive region growing provides delineation of individual tree crowns. The conducted experiments confirmed the reliability of the proposed method and showed its high potential in LiDAR image analysis for object detection and segmentation.

Assessing Knowledge Ambiguity in the Creation of a Model Based on Expert Knowledge and Comparison with the Results of a Landscape Succession Model in Central Labrador

Sustainable forest management (SFM) recognizes that the spatial and temporal patterns generated at different scales by natural landscape and stand dynamics processes should serve as a guide for managing the forest within its range of natural variability (Landres et al. 1999; Gauthier et al. 2008). Landscape simulation modeling is a powerful tool that can help encompass such complexity and support SFM planning (Messier et al. 2003). Forecasting the complex behaviors of a forested landscape involving patterns and processes that interact at multiple temporal and spatial scales poses significant challenges (Gunderson and Holling 2002). Empirical evidence for the functioning of key elements, such as succession and disturbance regimes, is crucial for model parameterization (Mladenoff 2004). However, reliable empirical data about the forest vegetation dynamics that arise in response to forest management and other disturbances may be scarce, particularly in remote areas where harvesting activity has been historically limited.

Perceptions of Small Private Forest Owner’s Vulnerability and Adaptive Capacity to Environmental Disturbances and Climate Change: Views from a Heterogeneous Population in Southern Quebec, Canada

A study on the perception of vulnerability and adaptive capacity to climate change (CC) was realised among 27 small private forest owners (SPFOs) of a region in southern Quebec. In-depth semi-structured interviews were conducted with SPFOs of diverse profiles to better understand their perception of environmental disturbances and their needs to improve forest management in relation to global change and more precisely to CC. The main purpose of the research was to better understand whether perceptions of vulnerability and adaptive capacity to CC can constitute a barrier to proactive actions toward adaptation. Qualitative data shows a spectrum of attitudes and perceptions which highlight how SPFOs identify different potential and actual disturbances and assess the risk they represent for their forest-based activities. It shows how place-based experiences of environmental disturbances shape perceptions of vulnerability and capacity to adapt to disturbances. Factors such as access to financial resources and perceived resilience of forest ecosystem influence perceived adaptive capacity. Most SPFOs who participated in the research do not perceive their forest or forest-based activities to be vulnerable to CC, which may constitute a barrier to proactive adaptation to CC. The awareness of CC as a general phenomenon does necessarily translate into adaptation in forestry practices. Yet, many participants expressed a need for better access to knowledge and financial support to improve adaptive capacities to CC and broader environmental or economic stressors.

Tree Death Not Resulting in Gap Creation: An Investigation of Canopy Dynamics of Northern Temperate Deciduous Forests

Several decades of research have shown that canopy gaps drive tree renewal processes in the temperate deciduous forest biome. In the literature, canopy gaps are usually defined as canopy openings that are created by partial or total tree death of one or more canopy trees. In this study, we investigate linkages between tree damage mechanisms and the formation or not of new canopy gaps in northern temperate deciduous forests. We studied height loss processes in unmanaged and managed forests recovering from partial cutting with multi-temporal airborne Lidar data. The Lidar dataset was used to detect areas where canopy height reduction occurred, which were then field-studied to identify the tree damage mechanisms implicated. We also sampled the density of leaf material along transects to characterize canopy structure. We used the dataset of the canopy height reduction areas in a multi-model inference analysis to determine whether canopy structures or tree damage mechanisms most influenced the creation of new canopy gaps within canopy height reduction areas. According to our model, new canopy gaps are created mainly when canopy damage enlarges existing gaps or when height is reduced over areas without an already established dense sub-canopy tree layer.