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Tree detection and canopy area measurement are important and difficult tasks in forest inventory, which are important for understanding forest stand structure. This study utilized remotely piloted aircraft (RPA) aerial photography technology to collect remote sensing images of forests in Xiong County, China, creating a dataset comprising 1200 images of six tree species. Based on this dataset, the paper proposes an optimized model, Att-Mask R-CNN, for canopy detection and segmentation. Att-Mask R-CNN outperforms the original models (Mask R-CNN and MS R-CNN) by achieving 65.29% mean average precision for detection, 80.44% mean intersection over union for segmentation, and 90.67% overall recognition rate for the six tree species. In addition, a pixel statistics method based on segmentation masks is introduced for estimating the vertical projected area of individual tree crowns, and comparisons between the measured and predicted vertical projected area of the crowns of six tree species (100 trees of each class) show an overall goodness-of-fit R2 of 85% and a relative root-mean-square error rRMSE of 12.81%. By using remote sensing images from RPAs and optimizing existing deep learning models, the detection and segmentation of individual tree canopies can be achieved, resulting in a more accurate understanding of forest structure, which provides scientific support for forest management and resource monitoring. [ABSTRACT FROM AUTHOR]

Although stakeholders' participation in forest management helps overcome problems and conflicts that prevent sustainable solutions, different approaches and nomenclature for similar contents in the literature hinder theoretical progress on the topic. This study organises existing information through a bibliometric analysis of scientific papers from the last 30 years (1991–2021) on sustainable forest management, focusing on the stakeholders' participation. Results demonstrate that stakeholders' participation in sustainable forest management gained relevance from 2017 onwards. Case studies are predominant (66%) and six major trends were identified. The first emphasises a systemic approach to participation. The second updates the community management discussion. The third studies historical problems related to the use of resources, rights, and services. The fourth focuses on regional assessments and studies. The fifth concerns assessment, decision-making, and planning, including issues related to certifications and policies. The sixth discusses innovation related to adaptation, climate change, equity, and resilience. The studies included in this last classification are problem-solving-oriented and seek new forest management. Although important, the role of innovation in stakeholders' participation in sustainable forest management is overlooked, which constitutes an avenue for future research. [ABSTRACT FROM AUTHOR]

Precommercial thinning could be a valuable tool for climate change adaptation, as it can promote stand diversity while increasing productivity. Softwood and hardwood stands are usually thinned following different methods, and we lack recommendations for application in mixedwood stands. We evaluated the effects of precommercial thinning on the growth and composition of balsam fir (Abies balsameaL.)–birch stands dominated by paper and yellow birch (Betula papyrifera Marsh. and Betula alleghaniensis Britt.), comparing methods and production objectives (systematic release-softwood, systematic release-mixedwood, crop-tree release-mixedwood, and crop-tree release-hardwood) in Québec (Canada). Precommercial thinning increased tree-level and stand-level growth, especially for both birches. Compared to the non-thinned control, thinning increased tree diameter at breast height annual increments by 60%–107%, with similar results among modalities. Thinning changed initial stand composition, but mixedwood production plots composition was similar to that of the control 15 years after treatment. Promoting diversity is often perceived to be made at the expense of wood production. Our results suggest that we can obtain both increased growth and maintain diversity. Precommercial thinning is currently suggested as an adaptation tool that can foster drought resistance. Based on our study, we suggest it could serve another purpose in climate-adapted forest management, that is, maintaining diversity and thus increasing resilience to disturbances. [ABSTRACT FROM AUTHOR]

Forest succession is a dynamic process of progressive compositional development of ecological communities of species following natural or anthropogenic disturbance. Despite a rich history of conceptual frameworks, models, and empirical advances, the complex interactions among climatic conditions, disturbances, edaphic factors, and silvicultural treatments still challenge our ability to accurately predict forest succession, hindering application to forest management. Our goal was to improve understanding of forest succession in the managed boreal forests of North America by clarifying advances in knowledge and limitations in our understanding. We reviewed 152 peer-reviewed papers to: (i) document conceptual developments in forest succession; (ii) summarize drivers of North American boreal forest succession, including changes to forest composition and successional trajectories given climate change; and (iii) discuss the implications of the synthesized information for boreal forest management. While the element of stochasticity is expected to increase under climate change, successional dynamics are anticipated to remain predominantly deterministic. Southern boreal forests are at increased risk of mortality due to warming-driven drought and increased fires. Following disturbance, regeneration is likely to favor deciduous hardwoods. In boreal mixedwoods, increased fires would promote jack pine, and also black spruce on hydric and xeric sites. Dynamics of the northern boreal will depend on the balance between precipitation and evapotranspiration. Forest management must carefully select prescriptions to promote forest regeneration and composition that consider the long-term effects of changing climate and disturbance regimes. For instance, combining retention cut with mechanical site preparation would maintain site productivity and reverse open black spruce stand development in northern boreal stands. Our work shows that multiple disturbances have compounding effects on forest development, but further work is needed to better define thresholds for synergistic and buffering interactions. Modeling of boreal forest succession can be improved by incorporating more of the influential factors, but this is often limited by the lack of data. This information will guide the development of forest management strategies by exploring combinations of prescribed fire and variable intensity selection cutting systems to reproduce the effects of multiple interacting natural disturbances under climate change on successional dynamics. [ABSTRACT FROM AUTHOR]

Sustainability is central to forest management. To determine the sustainable annual harvest, practitioners rely on a simulation framework that combines inventory data, growth models, and optimization software. Because this standard simulation framework is based on model predictions aggregated into yield tables, it may not properly capture natural dynamics. In this paper, we designed an alternative simulation framework that does not require aggregated model predictions. However, the growth model must implement a harvest submodel and produce stochastic predictions. To showcase this alternative simulation framework, we used a forest management unit in southwestern Quebec, Canada, and compared our simulation results with those of the standard simulation framework. Our alternative simulation framework showed that the standing volume of most coniferous species would decrease, whereas that of maple species would increase over the 21st century. The annual harvest of one species as determined through the standard simulation framework was found to be unsustainable in the alternative simulation framework. Being much lighter in terms of computation, this alternative simulation framework can be used as a complement to the standard simulation framework, notably for checking if the optimization-based annual harvest is sustainable. [ABSTRACT FROM AUTHOR]

Seeking to generate a deeper methodological and theoretical dialogue between botanical science and anthropology, this paper summarizes interdisciplinary approaches to human–plant interactions we have described as "sensory ecology" and "phytoethnography", applying these concepts to vital questions about human–plant relations in Amazonia. Building on this work, we broaden the scope of our investigations by considering their relevance to the field of historical ecology. In particular, we discuss Eduardo Viveiros de Castro's concept of "multinaturalism" and explore how it can be applied to understanding management and domestication of forest landscapes in Amazonia by Indigenous Peoples. [ABSTRACT FROM AUTHOR]

In this paper, we examine the implications of managing for sustained yield in a world characterized by growing risk and uncertainty. We review the history of sustained yield (SY) forestry in North America, with an emphasis on economic benefits and the persistence of the SY paradigm today, despite a publicized shift towards managing for a wider range of forest values called sustainable forest management (SFM). We show that current forest management goals around sustainability as well as SFM indicators are still predicated on maximizing harvest levels and timber flows. We build a simple model to explore the implications of SY under extreme (fat-tailed) risk assumptions to show that maximizing a level of harvest without adequately accounting for risk leads towards the depletion of the forest stock with a corresponding decline in the forest economy. We discuss these results in relation to real-world events such as the increase in catastrophic fires and pest outbreaks like the mountain pine beetle in Western Canada. We then examine the theoretical and practical implications that flow from this model and analysis. [ABSTRACT FROM AUTHOR]