Climate Change Underneath Forest Canopies

2020. May 29. - 13:58 A researcher from the UD has participated in the work of the international research group that established that the opening of forest canopies exerts an effect of heat stress on the flora in the forest underbrush. The findings of the research project were published by prestigious Science magazine.

As announced in the publication of an international research group, heat stress and shock could be caused in forest organisms by gaps in forest canopy or open canopies. Florian Zellweger, a researcher of Cambridge University and of The Swiss Federal Institute for Forest, Snow and Landscape Research, together with his colleagues, managed to become the first ever to prove the theory of climate change taking place under forest canopies. A participant in the research efforts was a student of UD’s Juhász Nagy Pál Doctoral School Balázs Teleki, a doctoral candidate of MTA-DE Lendület Funkcionális és Restaurációs Ökológiai Kutatócsoport [MTA-DE ‘Lendület’ Functional and Restoration Ecology Research Group], who specializes in the research on processes of forest dynamics and the effect of shrub spreading on the species pool of dry grasslands.

The data providing the basis for the report on the international study published in Science magazine come from a long-term monitoring project focused on observing the forest canopies across the world at almost 3000 individual locations. Balázs Teleki and his co-researchers repeated surveys on forest flora that had been conducted 50 or 60 years ago in several regions of Hungary. From the mountain ranges of Északi-középhegység [North Hungarian Mountains] through Dunántúli-középhegység [Transdanubian Midmountains] to one of the westernmost regions in Hungary called Őrség, they took 200 floral samples altogether to compare the findings of the first survey with those of the repeated survey and the micro-climate measuring data.

“It can be clearly seen in the data that, as a consequence of the opening of the forest canopy, the temperature at the bottom of the forest drastically increases, which exerts a kind of heat shock on the species of the underbrush. It is also apparent even in the samples collected in Hungary that, during the course of the past decades since the first survey, the forest canopy cover has significantly opened up in the areas under scrutiny,” said Balázs Teleki to hirek.unideb.hu.

The global warming of the climate is primarily recorded and examined in open areas. However, the data collected there have only a restricted significance for forest organisms, whereas the majority of land species in the world would live in forests.

Tree canopy cover protects living organisms in forests from extreme temperatures. Increasing tree canopy cover decreases the chance of overheating for organisms living underneath it. Loss of canopy cover, however, leads to increased local heat. Open canopies may allow for such sudden climatic effects that plants simply cannot survive.

For the species in the underbrush, this may be fatal because, for each forest organism, there is an optimal temperature, which they can adjust to the changing conditions only rather slowly. If the temperature is too high, the species preferring cool conditions either die out or become suppressed by species with a preference to heat.

Press Office/MTI