Simulated nitrogen deposition affects wood decomposition by cord-forming fungi
Simulated nitrogen deposition affects wood decomposition by cord-forming fungi
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DOI：
10.1007/s00442-011-2057-2
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发表时间：
2011-12-01
期刊：
影响因子：
2.7
通讯作者：
Darrah, Peter R.
中科院分区：
文献类型：
--
作者：
Bebber, Daniel P.;Watkinson, Sarah C.;Darrah, Peter R.
人为氮沉降影响许多自然过程，包括森林凋落物分解。腐解真菌是温带生态系统中唯一能够完全分解木质纤维素（木质）凋落物的生物，因此真菌对N沉降的响应对于理解全球变化对森林碳循环的影响至关重要。植物凋落物在高氮条件下的分解已被广泛研究，结果各不相同。森林地面生物群的复杂性和凋落物质量的变化掩盖了N海拔对分解者的影响。田间实验通常使用标准化的底物和N水平，但很少有研究控制腐烂生物。分解的山毛榉（山毛榉）块接种两个索形成的担子菌真菌，丝状丝孢菌和绒毛革菌，在英国牛津郡的怀瑟姆伍德模拟N沉降的现实水平下进行了实验比较。绒毛毛孢菌的质量损失大于H.而N处理组则显著高于对照组。分解伴随着真菌菌丝体的生长和剩余木材中N浓度的增加。我们属性的木材腐烂的影响，以响应索形成木材腐烂真菌的N可用性。以前的研究表明，这些真菌的能力，通过一个易位网络的菌丝体腐烂和进口的木材。这项研究表明，氮的可用性的小的增加，可以增加木材分解这些生物体。枯木是重要的碳储存和栖息地。木材分解者对人为氮沉降的响应应被考虑在森林碳动力学模型中。
Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carbon cycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at Wytham Wood, Oxfordshire, UK. Mass loss was greater with P. velutina than with H. fasciculare, and with N treatment than in the control. Decomposition was accompanied by growth of the fungal mycelium and increasing N concentration in the remaining wood. We attribute the N effect on wood decay to the response of cord-forming wood decay fungi to N availability. Previous studies demonstrated the capacity of these fungi to scavenge and import N to decaying wood via a translocating network of mycelium. This study shows that small increases in N availability can increase wood decomposition by these organisms. Dead wood is an important carbon store and habitat. The responses of wood decomposers to anthropogenic N deposition should be considered in models of forest carbon dynamics.