Climate costs of boreal forest clear-cutting – a multiscale experiment

Project: ResearchInterdisciplinary research

Research areas and keywords

Keywords

  • Full greenhouse gas budget (CO2, CH4, N2O, H2O) of a boreal forest, Full greenhouse gas budget of a clear-cut, Quantification of the boreal forest as sink of GHGs, Forest management, Calibration of ecosystem model for forestry management

Description

The 2015 Paris Agreement recognizes the importance of sinks and reservoirs of greenhouse gases (GHGs) and the associated role of forests (Art 5). In Sweden, rotation forestry with clear-cutting followed by planting is the predominant management regime. This project aims to assess the biotic and abiotic climate effects (“costs”) of rotation forestry at the boreal research site with Sweden's longest record of GHG exchanges.

Long-term records and understanding of the impact of major clear-cuts on the GHG budget are essential for assessment and policy recommendations for forest management, to improve National Inventory Reporting, and to calibrate and validate ecosystem models, ultimately reducing the inherent uncertainty of global GHG budgets and climate predictions.

We will deliver a rich dataset of below and above ground measures for a full GHG budget from Norunda as forest and as clear-cut. Using this dataset, we will calibrate an ecosystem model and analyse scenarios of alternative reforestation strategies driven by climate model data of the three main RCPs. The model approach combined with remotely sensed data of similar boreal forest transitions will improve quantification and reduce uncertainties of the sink and source terms for areas with intensive forest management at national and regional scale. Our results will allow strategic investment in the forestry sector with regards of fulfilling the Paris Agreement or the even more ambitious Swedish climate mitigation targets.

Layman's description

The 2015 Paris Agreement set an ambitious goal to limit global warming well below 2˚C and suggested to reduce greenhouse gas (GHG) emissions drastically. It also recognised the importance of sinks and reservoirs of GHGs as well as the importance to strengthen these sinks. Article 5 of the agreement specifically emphasises the importance of our forests.

The boreal region forms a nearly continuous circumpolar belt of forest extending between 50˚ and 70˚ N in Europe, Asia, and North America. This forest covers some 12 million square kilometres and constitutes the world‘s second largest forested region after the tropical forest. The boreal forest is a net sink for greenhouse gases (GHGs). It removes and stores on average 500 mio tonnes carbon from the atmosphere every year. This is about 20% of the global terrestrial carbon sink. Forest management regimes have a major impact on this terrestrial carbon sink. For example, at what stand age a forest is clear-cut, and what tree species is selected for regrowth, is a key decision, as the trees planted today may grow for 60-120 years and thereby experience and possibly affect future climate.

In Sweden, boreal forest covers a large area, and rotation forestry with final felling followed by planting is the predominant management regime here. Our study site Norunda is located in central Sweden and is one of few boreal forest research sites globally with records of carbon dioxide (CO2) exchange between land and the atmosphere spanning over more than 20 years. The forest at Norunda will be clear-cut in 2021/22. This project therefore provides the ultimate last opportunity to both apply interdisciplinary technology to collect so far missing belowground and aboveground information of the forest, and to measure the full greenhouse gas balance (including CO2, methane, nitrous oxide, water vapour), such that we can observe the changes introduced with the clear-cut.

Our data will allow calibrating so-called ecosystem models. These models simulate GHG sinks and sources from land and vegetation and provide essential information to run climate models. We will calibrated such an ecosystem model and run it for a range of reforestation strategies (e.g., different tree species) and for three climate change scenarios. We will also use satellite data to detect and model areas of similar boreal forest transitions, with the goal to derive better estimates of the sink and source terms for areas with intensive forest management at national and regional scale. Our results will allow strategic investment in the forestry sector with regards of fulfilling the Paris Agreement or the even more ambitious Swedish climate mitigation targets. It will further provide essential information for the National Inventory Reporting to the UN climate convention.
AcronymCORE
StatusActive
Effective start/end date2018/12/012022/12/01

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Participants