Does the age of trees influence forest ecosystems?
Forest ecosystems are generally vulnerable to climate change. What factors most influence European forests’ resilience, stability, and productivity?
A research group from the Forest Modelling Laboratory of CNR-Isafom (the Institute for Agricultural and Forestry Systems of the Mediterranean) has specifically analyzed the impact of tree age and forest stands on forest ecosystems.
What factors characterize forest ecosystems?
Forest ecosystems are characterized based on altitude, climatic conditions, substrate, and the anthropogenic interventions that have occurred over time.
According to the research findings, the age of trees and forest stands—shaped by past forest management practices in terms of diversity and structural and physiological characteristics—has a decisive influence on the stability of forest ecosystems.
The influence of these factors is such that it affects their ability to mitigate climate change.
This conclusion was reached by research conducted by the CNR-Isafom in Perugia together with the Forest Geomatics Laboratory of the University of Florence. The results are published in the journal “Journal of Environmental Management and Forests.”
The analysis with advanced evaluation systems
The Forest Geomatics Laboratory specializes in studying forest ecosystems, also through advanced simulation systems.
The Three Dimensional Coupled Model Carbon Cycle (3D-CMCC) has highlighted that the age of populations significantly affects their carbon balance, carbon assimilation, and productivity.
Moreover, trees’ age affects forests’ resilience and stability under current and future climatic conditions.
The researchers examined European sites of Scots pine, Norway spruce, and beech, three of Europe’s most important and common species at various ages. Thanks to the CNR’s biogeochemical model, they analyzed scenarios of natural evolution in a future without human interventions.
The scenarios of change
Elia Vangi, a postdoc in the Forest Modelling Lab of Cnr-Isafom and the lead author of the research, explains, “Analyzing the impact of climate change and age on European forests, using five different scenarios, it emerges that—for all the species studied—the differences between the ages of the forests are more significant than those between climate scenarios.“
Forest productivity peaks in young and middle-aged stands (16-50 years), regardless of climatic conditions.
In particular, beech forests prove to be stable and resilient with the increase of atmospheric CO2 and temperature, showing an increase in aboveground biomass – crowns and trunks – which, on the other hand, decreases in spruce forests, especially in older age classes.
The Scots pine has a more stable CO2 storage capacity than other species, but it is experiencing a decrease in annual volume growth. “Understanding these dynamics is crucial for developing effective management strategies.”
The diversity of species and ages strengthens forests. Therefore, promoting species and age diversity within forests can enhance their resilience and adaptability to future climate changes.
The climate future is uncertain. How can forest ecosystems be protected? According to researchers, young forests may grow faster but have a shorter lifespan. Which mature trees could have more stability and resilience due to the greater amount of carbon accumulated and a better capacity for adaptation?
Therefore, considering trees’ age and responses to climate change will be key to developing the right forest management approaches.