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The oil and gas industry has grown significantly throughout the boreal and arctic ecosystems of North America. A major feature of the ecological footprint of oil and gas exploration is seismic lines-narrow corridors used to transport and deploy geophysical survey equipment. These lines, which traverse forests, tundra, uplands, and peatlands, were historically up to 10 m wide. Over the past decade, seismic lines have decreased in width (in some cases down to 1.75-3 m); however, their density has increased drastically and their construction is expected to continue in regions of Canada and the United States that are rich in oil and gas resources. We examine the literature related to the environmental impacts of, and restoration and reclamation efforts associated with, seismic lines in the boreal and arctic ecosystems of North America. With respect to conventional seismic lines, numerous studies report significant and persistent environmental changes along these lines and slow recovery of vegetation that translates into a lasting fragmentation of the landscape. This fragmentation has many ramifications for biodiversity and ecosystem processes, including significant implications for threatened woodland caribou herds. While modern, low-impact seismic lines have comparatively lower ecological effects at the site-level, their high density and associated potential edge effects suggest that their actual environmental impact may be underestimated. Seismic line restoration is a critical aspect of future integrated landscape management in hydrocarbon-rich regions of the boreal-arctic, and if widely applied, has the potential to benefit a wide range of species and maintain or re-establish key ecosystem services such as carbon sequestration and biodiversity. [ABSTRACT FROM AUTHOR]

Ecosystem responses to current global climate change can be predicted through experimental climate simulations. One such simulation method is the open-top chamber (OTC). The effects of OTCs on environmental factors are potentially complex, and recognizing the numerous interactions among these factors is crucial for the proper use of chambers. We studied the effects of OTCs on microclimatic factors including ambient temperature, relative humidity, soil temperature, and soil moisture. Plant abundance responses were also assessed. Our study involved the construction of 20 OTCs (1 m in diameter and 0.75 m in height; made of clear acrylic plastic) and 20 control plots on substrates with and without Sphagnum moss, at post-fire and logging sites of the transitional mixedwood-boreal forest in the southern part of James Bay region, Quebec. Experimental trials were also conducted to test the effects of OTCs on snowmelt in the Montreal region. Our results suggest that OTC treatment is most evident in terms of increased daytime maximum temperatures (2°C to 3°C), and cooler (up to ∼2.4°C), drier (up to 10% volumetric moisture content) soils. Advanced thawing of the insulating snow cover and exposure of soil in the OTCs to low spring temperatures appeared to prolong soil freeze and result in cooler soils. Earlier snowmelt probably also led to earlier onset and overall increased evaporation of meltwater in the OTCs, leading to drier soils. Plant abundance responses to OTC treatment differed depending on plant species. Overall, open-top chambers provide an effective and simple method of climate change simulation, but it is highly advisable that the complex interactive effects, both desired and undesired, are well understood and appreciated before using OTCs for experimental climate simulation. [ABSTRACT FROM AUTHOR]

Open-top chamber (OTC) climate change simulation was used to predict the potential effects of climate change on biogeochemistry, including: 1) soil decomposition of three litter types (trembling aspen ( Populus tremuloides Michx.), black spruce ( Picea mariana (Miller) BSP), and Sphagnum); 2) soil nutrient supply rates, and; 3) soil acidity. We assessed the effects of OTCs on these biogeochemical factors in the presence or absence of Sphagnum moss substrate at post-fire and logging sites, in the transitional mixedwood-boreal zone of northwestern Quebec. Higher air temperatures and cooler, drier soils created by the OTC treatment resulted in lower decomposition rates and a higher C:N ratio of aspen litter, and lower Ca concentrations of the Sphagnum litter after 14 months of incubation, as well as lower K concentrations of spruce litter after 24 month incubation. There were no effects of the OTC treatment on decomposition rates for Sphagnum and spruce litter. The nutrient supply rates of Ca and Mg were consistently lower in the OTCs. The supply rates of N were significantly higher in the control plots at the logging site than at any other combination of the OTC treatment and disturbance site. Soil pH was lower in the OTCs by the end of the growing seasons in 2006 and 2007. The results suggest that the impact of climatic changes, as simulated by the OTC treatment, on the soil system of mixedwood-boreal post-disturbance sites is likely to affect biogeochemical processes such as nutrient supply rates and the soil pH, but the effects on decomposition may be minimal. [ABSTRACT FROM AUTHOR]

Various effects on plant growth associated with handling or touching plants are well documented from greenhouse and laboratory studies, but are generally unknown or ignored under field conditions. We examined the prevalence of the effects of handling, at levels typical of many ecological experiments, on aboveground biomass and damage by invertebrate herbivores for a total of 16 common species from three plant communities in western Canada. Significant effects of handling were observed in the alpine meadow and grassland, but not in the boreal forest. Handling reduced aboveground biomass and increased the mean intensity of invertebrate leaf damage for most species. A meta-analysis of the relationship between plant traits and response to handling indicated that woody plants and species without strong chemical or conspicuous morphological defenses were most strongly affected. Overall, our results indicate that potentially confounding effects of routinely sampling plants in the field are widespread and merit further investigation. [ABSTRACT FROM AUTHOR]

This paper reviews trends in the academic literature on cumulative effects assessment (CEA) of disturbance on forest ecosystems to advance research in the broader context of impact assessments. Disturbance is any distinct spatiotemporal event that disrupts the structure and composition of an ecosystem affecting resource availability. We developed a Python package to automate search term selection, write search strategies, reduce bias and improve the efficient and effective selection of articles from academic databases and grey literature. We identified 148 peer-reviewed literature published between 1986 and 2022 and conducted an inductive and deductive thematic analysis of the results. Our findings revealed that CEA studies are concentrated in the global north, with most publications from authors affiliated with government agencies in the USA and Canada. Methodological and analytical approaches are less interdisciplinary but mainly quantitative and expert-driven, involving modeling the impacts of disturbances on biophysical valued components. Furthermore, the assessment of socioeconomic valued components, including the effects of disturbance on Indigenous wellbeing connected to forests, has received less attention. Even though there is a high preference for regional assessment, challenges with data access, quality, and analysis, especially baseline data over long periods, are hampering effective CEA. Few articles examined CEA – policy/management nexus. Of the few studies, challenges such as the inadequate implementation of CEA mitigation strategies due to policy drawbacks and resource constraints, the high cost of monitoring multiple indicators, and poor connections between scenarios/modeling and management actions were paramount. Future CEA research is needed to broaden our understanding of how multiple disturbance affects forests in the global south and coupled social and ecological systems and their implications for sustainable forest management. • We review cumulative effect assessments of disturbances in forest ecosystems. • The study developed a Python package to automate the search term selection. • We identified 148 peer review and grey literature across 29 countries. • Most studies are located in the global north, and methodologies are expert-driven. • Study should focus on how disturbance affects coupled social and ecological systems. [ABSTRACT FROM AUTHOR]