( L* J% f8 ?, w6 K" |$ C9 p6 p
AM真菌在生态系统中的作用 ; p3 C+ s* ?, m) [7 @" z. i 3 D! h$ b) h4 r9 d9 b ! ^ k+ L5 M4 O# L! U; Y, J& g2 O% M/ Y! _% a2 W$ \
1 r' M0 A7 O5 s0 e* b) j
Forests accumulate and store large amounts of carbon (C), and a sub' r: n8 h( }3 E4 N
stantial fraction of this stock is contained in deadwood. This transient pool is subject. J% x% m0 Q- [! m3 | c4 H: w3 N
to decomposition by deadwood-associated organisms, and in this process it contrib 5 O4 l/ a' R# A# c0 S( ]3 Uutes to CO2 ! G% A5 Z8 N. M& o
emissions. Although fungi and bacteria are known to colonize dead 4 U! ]! k( k2 R1 I4 c. Lwood, little is known about the microbial processes that mediate carbon and nitro0 L d% y- s- V. t* l( q/ e/ r
gen (N) cycling in deadwood. In this study, using a combination of metagenomics,% f; T% u+ E1 R3 U1 r) [. }
metatranscriptomics, and nutrient flflux measurements, we demonstrate that the decom$ C& ]$ H0 o( V3 d3 t0 p7 V
position of deadwood reflflects the complementary roles played by fungi and bacteria.2 E! {% U3 v+ |3 C
Fungi were found to dominate the decomposition of deadwood and particularly its re! Z2 [9 ?3 @' v3 L, p e
calcitrant fractions, while several bacterial taxa participate in N accumulation in dead : x% R5 s( H8 zwood through N fifixation, being dependent on fungal activity with respect to deadwood! I8 g+ Q$ M; X! b& |! i
colonization and C supply. Conversely, bacterial N fifixation helps to decrease the con, m& }) j5 K9 C& L* ]" v2 N
straints of deadwood decomposition for fungi. Both the CO2 efflflux and N accumulation " V4 b: w! i3 ^- fthat are a result of a joint action of deadwood bacteria and fungi may be signifificant for- \1 y. [' }* C9 s+ `- N1 B
nutrient cycling at ecosystem levels. Especially in boreal forests with low N stocks, dead( j Z; R3 u; Y7 s2 D
wood retention may help to improve the nutritional status and fertility of soils.% K4 ?2 A) {" Q8 M# F% L- t
. g5 j! C- p! J" c ?- L
IP卡
狗仔卡
发表于 2021-2-5 07:42
转播
淘帖
分享
收藏
支持
反对
微信
提升卡
置顶卡
沉默卡
喧嚣卡
变色卡
抢沙发
显身卡
