2 N( P9 D; j3 e+ TAM真菌在生态系统中的作用# c- { E" a" v8 d+ r
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Forests accumulate and store large amounts of carbon (C), and a sub7 k, [/ S% X$ }& \9 \$ e
stantial fraction of this stock is contained in deadwood. This transient pool is subject 2 ^) S1 W X$ F# P6 z9 @to decomposition by deadwood-associated organisms, and in this process it contrib ) z5 {! Z9 |! X7 futes to CO2 9 i9 o, Y; b2 s A r, L# |
emissions. Although fungi and bacteria are known to colonize dead ! Q8 j+ _# [2 ^+ Ewood, little is known about the microbial processes that mediate carbon and nitro' _* G! J% w, H v; d' u. ?
gen (N) cycling in deadwood. In this study, using a combination of metagenomics,' Y6 Q& V5 e3 h A8 F3 ]; _
metatranscriptomics, and nutrient flflux measurements, we demonstrate that the decom+ w. A) B9 h4 e+ K7 `3 \
position of deadwood reflflects the complementary roles played by fungi and bacteria.- |, L7 F% ~( y% ?0 f( X6 {
Fungi were found to dominate the decomposition of deadwood and particularly its re 6 T) D$ r( W4 U8 S o. T3 |8 x y! _( h7 mcalcitrant fractions, while several bacterial taxa participate in N accumulation in dead * G# f( `7 E% o+ v. p- Rwood through N fifixation, being dependent on fungal activity with respect to deadwood 1 Y# x M/ s* Ucolonization and C supply. Conversely, bacterial N fifixation helps to decrease the con 7 H4 F. u `" F Nstraints of deadwood decomposition for fungi. Both the CO2 efflflux and N accumulation 0 N0 Y/ B& u' [# Lthat are a result of a joint action of deadwood bacteria and fungi may be signifificant for! ^1 u- y. p( b+ K' Z
nutrient cycling at ecosystem levels. Especially in boreal forests with low N stocks, dead , l4 t7 P; h ]4 L* Q! [wood retention may help to improve the nutritional status and fertility of soils. % K/ f. O# L1 p( n1 y6 X8 ~7 f" n, F) }' i. p( c
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