Linkages between environmental factors and fungal functional gene composition
The increase of winter soil temperature and associated changes of soil hydrologic conditions (including soil moisture and thaw depth) and GPP in the growing season significantly contributed to the differences of functional gene composition (CCA model: F = 1.57, P = 0.01) (Fig. 3a). Those factors explained 47.25% of the differences, among which winter soil temperature explained 10.35%, soil hydrologic conditions explained 20.10%, and GPP explained 12.48% (VPA, Fig. 3b).
Linkages between fungal C degradation genes and R eco
In line with the third hypothesis,R eco had positively linear regressions with the relative abundances of fungal C degradation genes encoding xylose reductase (R 2 = 0.56, P < 0.01), vanillin dehydrogenase (R 2 = 0.44,P = 0.02), glyoxal oxidase (R 2 = 0.32,P = 0.03), and aspartate protease (R 2 = 0.33, P = 0.03) (Fig. 4).