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Context: Forest management practices that conserve biodiversity and maximize carbon sequestration under climate change are needed. Although post-windthrow salvage logging and scarification can reduce carbon dioxide (CO2) emissions within ecosystems by removing downed logs, they can greatly affect species composition. Additionally, salvage logging may increase CO2 emissions based on a cradle-to-grave analysis of salvaged wood. Objectives: We aimed to assess the effects of changes in climate, windthrow regimes and post-windthrow management on aboveground biomass, species composition, and carbon balance in the forest sector by combining forest landscape simulations and life cycle assessment (LCA). Methods: The study landscape is a 12,169 ha hemiboreal forest located in northern Japan. We simulated 115 years (2015–2130) of forest dynamics in 36 scenarios based on features of the climate, windthrow regime, and management using the LANDIS-II forest landscape model. CO2 emissions related to management and salvaged wood were estimated by LCA. Results: Increases in the windthrow area, which was more vulnerable to climate warming, caused a shift to temperate broadleaved forests and a decrease in aboveground biomass. These were accelerated by the removal of advanced seedlings and dead wood, which greatly reduced the recruitment of Picea species. The 115-year cumulative net CO2 absorption of the forest sector, including carbon balance within ecosystems and CO2 emissions estimated by LCA, greatly decreased due to salvage logging (maximum 81%) and scarification (maximum 114%). Conclusions: Leaving downed logs and advanced seedlings is recommended to conserve boreal conifers and carbon sinks and maximize net CO2 absorption under climate change. [ABSTRACT FROM AUTHOR]

Oak-pine forests in the U.S. Central Hardwood Forests are recovering from exploitative harvesting and clearing in the early twentieth century and are undergoing rapid succession changes. Unprecedented red oak borer (ROB, Enaphalodes rufulus) outbreaks in 1999–2003 are associated with the largest oak mortality event reported in the Central Hardwood Region since the arrival of Europeans. Predicting and evaluating the effects of ROB disturbance on forest composition has practical value for forest management plans that aims to minimize ecological and economic loss from ROB disturbances. However, such prediction at a regional scale is rare due to the limited approaches that could explicitly couple insect outbreak mechanisms with forest dynamics under changing climate. We used a newly developed climate-sensitive Biotic Disturbance Agent module in the LANDIS PRO framework to simulate species composition changes due to succession, climate change, and ROB disturbances in 13.5 million ha forests in the U.S. Central Hardwood Region from 2000 to 2300. Our simulation suggested that succession is more important than climate effects and ROB disturbance in predicting regional species composition changes. ROB disturbance interacting with climate change accelerated the decline of primary host species (e.g., Quercus rubra) and then substantially changed forest succession trajectories under warming climates. Our modeling approach improved the simulation realism of ROB disturbance and more realistically projected how tree species will respond to ROB disturbance under changing climate, informing decision-making in silvicultural prescriptions and long-term management plans. [ABSTRACT FROM AUTHOR]

Context: Forests in the northeastern United States are currently in early- and mid-successional stages recovering from historical land use. Climate change will affect forest distribution and structure and have important implications for biodiversity, carbon dynamics, and human well-being. Objective: We addressed how aboveground biomass (AGB) and tree species distribution changed under multiple climate change scenarios (PCM B1, CGCM A2, and GFDL A1FI) in northeastern forests. Methods: We used the LANDIS PRO forest landscape model to simulate forest succession and tree harvest under current climate and three climate change scenarios from 2000 to 2300. We analyzed the effects of climate change on AGB and tree species distribution. Results: AGB increased from 2000 to 2120 irrespective of climate scenario, followed by slight decline, but then increased again to 2300. AGB averaged 10 % greater in the CGCM A2 and GFDL A1FI scenarios than the PCM B1 and current climate scenarios. Climate change effects on tree species distribution were not evident from 2000 to 2100 but by 2300 some northern hardwood and conifer species decreased in occurrence and some central hardwood and southern tree species increased in occurrence. Conclusions: Climate change had positive effects on forest biomass under the two climate scenarios with greatest warming but the patterns in AGB over time were similar among climate scenarios because succession was the primary driver of AGB dynamics. Our approach, which simulated stand dynamics and dispersal, demonstrated that a northward shift in tree species distributions may take 300 or more years. [ABSTRACT FROM AUTHOR]

Spatially explicit dynamic forest landscape models have been important tools to study large-scale forest landscape response under global climatic change. However, the quantification of relative importance of different transition pathways among different forest types to forest landscape dynamics stands as a significant challenge. In this study, we propose a novel approach of elasticity and loop analyses to identify important transition pathways contributing to forest landscape dynamics. The elasticity analysis calculates the elasticity to measure the importance of one-directional transitions (transition from one forest type directly to another forest type); while the loop analysis is employed to measure the importance of different circular transition pathways (transition from one forest type through other forest types back to itself). We apply the proposed approach to a spatially explicit dynamic model, LANDIS-II, in a study of forest landscape response to climatic change in the Boundary Waters Canoe Area (BWCA) incorporating the uncertainties in climatic change predictions. Our results not only corroborate the findings of the previous studies on the most likely future forest compositions under simulated climatic variability, but also, through the novel application of the elasticity and loop analyses concepts, provide a quantitative assessment of the specific mechanisms leading to particular forest compositions, some of which might remain undetected with conventional model evaluation methods. By quantifying the importance of specific processes (transitions among forest types) to forest composition dynamics, the proposed approach can be a valuable tool for a more quantitative understanding of the relationship between processes and landscape composition/patterns. [ABSTRACT FROM AUTHOR]