Carbon and Oxygen Gas Exchange in Woody Debris: The Process and Climate-Related Drivers

The carbon-to-oxygen relationship and gas exchange balance, organic carbon to CO2 conversion intensity and efficiency, and their relevance to climate parameters and wood decay fungi were investigated for birch woody debris (WD) in the Mid-Urals mixed pine and birch forests. It was shown that, within the range of temperatures from 10 to 40◦ C and relative moisture (RM) of wood of 40% and 70%, aerobic gas exchange was observed in the WD, encompassing the physiologically entwined processes of CO2 emission and O2 uptake. Their volumetric ratio (0.9) confirmed that (1) the WD represents a globally significant CO2 source and appropriate O2 consumer and (2) the oxidative conversion of organic carbon is highly efficient in the WD, with an average ratio of CO2 released to O2 consumed equal to 90%. The balance of carbon-to-oxygen gas exchange and oxidizing conversion efficiency in the WD were not affected by either fungal species tested or by moisture or temperature. However, the intensity of gas exchange was unique for each wood decay fungi, and it could be treated as a climate-reliant parameter driven by temperature (Q10 = 2.0–2.1) and moisture (the latter induced a corresponding trend and value changes in CO2 emission and O2 uptake). Depending on the direction and degree of the change in temperature and moisture, their combined effect on the intensity of gas exchange led to its strengthening or weakening; otherwise, it was stabilized. Aerobic respiration of wood decay Basidiomycetes is an essential prerequisite and the major biotic factor in the WD gas exchange, while moisture and temperature are its climatic controllers only. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The research was funded by RFBR, Government of the Sverdlovsk region, project number 20-44-660012, by State Assignment of Institute of Plant and Animal Ecology UB RAS (№ AAAA-A19-119031890084-6), by Program for Improving the Competitiveness of the Ural Federal University (the decree no. 211 of the Government of the Russian Federation, contract No. 02.A03.21.0006)

Carbon conversation activity and efficiency of xylotrophic basidiomycetes

It was shown that different groups of wood decaying fungi have the same efficiency of oxidative conversion of organic carbon of wood debris to CO2: ratio of CO2/O2 for polyporoid fungi is 0.82, agaricoid − 0.79, corticioid − 0.77 and heterobasidioid − 0.88. Polyporoid and corticioid fungi significantly differ in carbon conversion activity: 3.6 ± 0.25 and 2.0 ± 0.19 mg CO2/dm2 hour-1 respectively. The both groups of fungi have in 1.5–1.9 times lower carbon conversion activity on coniferous wood than on deciduous. White rot fungi have higher (4.1±0.3 mg CO2 / dm2 hour-1) activity than brown rot fungi (3.0±0.32 mg CO2 / dm2 hour-1).Работа выполнена при финансовой поддержке РФФИ (проект 15−04−06881)

SUBSTRATE SPECTRA AND DISTRIBUTION OF SPECIES GENUS DAEDALEOPSIS SCHROET

In Russia, genus Daedaleopsis Schroet. is represented by three morphological species: D. confragosa, D. septentrionalis and D. tricolor . It is shown that the species differ in the distribution and substrate spectra in this part of their areals: D. confragosa predominantly occurs on Salix, D. septentrionalis and D. tricolor on Betula, and apart from D. septentrionalis have the more limited distribution compared with D. confragosa and D. tricolor.Работа выполнена при поддержке Программы 211 Правительства РФ (соглашение № 02.A03.21.0006)