Risk of tree species decline under aridification
To align with CLIMB-FOREST's ambitious goal of ensuring resilient forests that support both people and nature in the face of climate change, the first essential step is quantifying the risk faced by tree species in this changing environment. In this commentary, the importance, complexities and uncertainties of quantifying the risk of tree species decline due to aridification by the end of this century are highlighted. Specifically, I discussed the valuable contribution of providing a quantitative assessment of species' risk under future climate conditions.
However, I also underscored the importance of continuing research and developing more comprehensive metrics to enhance our understanding of climate change impacts on forests, in line with CLIMB-FOREST's mission of guiding the forestry sector and policymakers in implementing effective mitigation and adaptation strategies.
Greenhouse Gas Fluxes in Forest Ecosystems
Forests are vital for climate change mitigation, absorbing CO2 while also emitting potent greenhouse gases like methane (CH4) and nitrous oxide (N2O) from trees and soil. These emissions, more potent than CO2, require careful scrutiny to understand forests' role.
Yet, our global understanding of forest greenhouse gas fluxes remains incomplete, particularly for CH4 in boreal and tropical regions. Forests' role in CH4 exchange varies from minor sink to major source, underscoring the need for additional observations. Studies on ecosystem-scale N2O fluxes in forests are also scarce.
This Research Topic “Greenhouse Gas Fluxes in Forest Ecosystems” aims to present the current state of research on the processes related to greenhouse gas fluxes in forest ecosystems and their biotic or abiotic drivers. The Topic covers studies that encompass greenhouse gas fluxes at various scales, from the soil and trees to the entire ecosystem, in a wide array of ecosystems globally. They provide new insights into how environmental changes, particularly land management practices, affect forest greenhouse gas potential while also highlighting critical questions for future research.
Secondary forests more sensitive to drought than primary forests
The majority of Swedish forest are secondary forests that are managed commercial forests with little diversity in species and structure. Only a small part is made up of primary forests that have experienced limited direct human impact.
So far, it has not been known how primary forests and managed secondary forests react to drought. In a new study published in the scientific journal Environmental Research Letters, a team of researchers led from Lund, analysed how the drought of 2018 affected the forest types. “The results showed that secondary forests in Sweden were more affected by the drought than primary forests were,” says Anders Ahlström, researcher in physical geography at Lund University.
Primary forests are rare in Sweden and in Europe. They represent the most untouched forests we have left, and they inform us of how nature looks and how it functions without major direct human impact. The forests, therefore, are especially important in understanding how environmental changes and human land use affect ecosystems and their processes.
