Impact of forest Management and Climate Change on understory Microclimate – MaCCMic

Forest canopies buffer climate extremes in the understory. This buffering capacity is key to explain understory biodiversity and forest regeneration, and thus forest resilience to climate change. It is also important for recreational activities. Forest management practices impact these ecosystem services by modifying forest structure and composition, and thus understory microclimate. Today, however, forest managers have no tool to quantify the impact of their practices on understory microclimate, notably in terms of climate extremes or under future climate conditions.
The objective of MaCCMic is to develop such tools that will help identify the main factors influencing forest understory microclimate and anticipate the impact of forest management (density, fragmentation, thinning, choice of species, understory removal, etc.) and climate change on forest microclimate and understory vegetation, notably in terms of climate extremes.
Bringing together long-term datasets of understory microclimate, state-of-the-art LiDAR and Sentinel2 products and biophysical forest microclimate modelling, we will quantify how understory microclimate is modified by local factors (canopy closure but also forest structure and functional diversity), landscape features (topography, but also the proximity of a river or the degree of fragmentation of the surroundings) and climate change (notably increasing atmospheric CO2 and its effect on plant physiology and forest regeneration).
To best tease apart the different factors influencing understory microclimate, we will integrate existing and comprehensive datasets of forest microclimate from Europe, North America and the Neotropical region, but will also design specific experiments or use biophysical microclimate models. Results from the project will then be synthetized and translated into clear recommendations and easy-to-use tools to help foresters understand the impact of climate change and their practices on understory microclimate.
For example, our results should help us write an expertise report on the impact of forest management on the understory microclimate in riparian forest corridors. Two web tools dedicated to forest owners and managers, but also the general public, will be also developed: (1) an interactive virtual forest that will show how forest management can influence understory microclimate during specific past and future extreme events and; (2) a web “tracker” that will summarise, based on near real-time data, how understorey microclimate is buffered and decoupled from its macroclimate, for a set of typologies of forests or tree plantations in a given region. Other expected outcomes of the project are: new teaching materials (for forest engineering schools or master programmes, but also middle schools), new microclimate datasets, software updates and technical notes, as well as 8 master reports, 3 PhD theses and several peer-reviewed articles.
The results of MaCCMic will be closely followed by the community of terrestrial ecologists interested in how climate change impacts forest biodiversity. These results should also strongly interest the global carbon cycle and climate change research community, by bringing new understanding of the biophysical and ecological mechanisms of forest regeneration and resilience under rising atmospheric CO2 concentrations. Our results on the impact of understory microclimate and atmospheric CO2 increase on forest regeneration and resilience should also interest strongly the research community working on the global carbon cycle and climate change. Finally, MaCCMic should have a strong impact on the forest sector by providing new tools to help forest managers increase the resilience of forests and foster their ecological, recreational and climate services in a warming world.