Study suggests that longer growing seasons do not imply increased tree growth

According to the research findings, the onset of leaf unfolding occurred earlier in the Aleppo pine (early March) than in the Scots pine (mid-May)

SF
Sara Machado - FCTUC
25 january, 2023≈ 3 min read

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English version: Diana Taborda

A study involving researchers of the Department of Life Sciences (DCV) of the Faculty of Sciences and Technology of the University of Coimbra (FCTUC) suggests that longer growing seasons do not necessarily lead to larger radial growth.

The research, which aimed to test how the length of a growing season affects tree growth, was published in the journal "Agricultural and Forest Meteorology", with the title “Decoupled leaf-wood phenology in two pine species from contrasting climates: Longer growing seasons do not mean more radial growth”.

“Climate warming is expected to lengthen the growing season of tree species. However, a longer growing season may not lead to an increase in wood production. For instance, summer drought could counterbalance the positive effect on forest productivity and tree growth of a longer growing season”, explains Filipe Campelo, researcher at the Centre for Functional Ecology of the UC and co-author of the study, further adding that “on the other hand, it is still unknown how tree phenology - in particular leaf unfolding and fall dates - affects growth, carbon uptake and, consequently, climate change mitigation by forests.”

According to the results of the study, the onset of leaf unfolding occurred earlier in the Aleppo pine (early March) than in the Scots pine (mid-May). “The results have shown that wood growth is decoupled from leaf phenology and a longer growing season does not always lead to increased radial growth or more carbon uptake.”, claims Filipe Campelo.

“The research further suggests that estimating the amount of carbon stored annually by forests should consider both the length of the growing season and the intra-annual variation in wood formation rates. This is crucial for a better understanding of the global carbon cycle and assessment of forests' role in regulating carbon dioxide in the atmosphere”, Campelo highlights.

The scientific article is available at https://www.sciencedirect.com/science/article/pii/S0168192322004105#sec0015