Dear Editor,

Forests are making a key contribution to tackling climate change. Yet major knowledge gaps exist on how they can be preserved in the face of the climate crisis. A new research project will address these gaps by modelling the effects of different forest interventions on climate change mitigation, water, and biodiversity.

Forests play a vital role in mitigating the effects of climate change. Therefore, measures such as reforestation as well as the prevention of deforestation and forest degradation are receiving increasing attention from governments and businesses. Despite this, large knowledge gaps exist on how different forest measures affect the resilience of the plants, biodiversity, and hydrology in the context of the climate crisis.

This lack of knowledge has wide-ranging effects: According to Anna Tengberg, senior advisor at Stockholm International Water Institute (SIWI), "There have been cases where forest measures have had unintended consequences, such as lowering of the groundwater table." Currently we lack the quantitative data to really know what combinations of measures are needed to make forests resilient to climate change. What is needed is to develop scenarios of what the impact of different measures would be.

The project 'Understanding and Securing the Resilience of Forest-based Climate Change Mitigation' will address these key knowledge gaps. The project will identify which forest mitigation measures should be implemented in a basin or landscape and will run simulations and search for forest measures that optimise mitigation, biodiversity, and hydrological benefits.

For the ideal combination, a range of factors needs to be considered, such as the location of the forest and the local climate and hydrology. These factors, in turn, impact the selection of plants and their spacing in forest-based mitigation measures. In addition to analysing effects of forest measures on climate mitigation, water, and biodiversity, the project will place strong emphasis on analysing the effects on affected local communities.

The project is a cooperation between SIWI, Stockholm Resilience Centre (SRC), Potsdam Institute for Climate Impact Research (PIK), and the WaterCentre@KTH. It builds on previous collaborations and advocacy for unpacking fresh water's role in climate mitigation with SRC, PIK, United Nations Development Programme, Deutsche Gesellschaft für Internationale Zusammenarbeit, and others.

The first stage of the project will run for four years, with the possibility of a second stage.

Jakob Schabus

Stockholm International Water Institute

jakob.schabus@siwi.org