Interactions between detritivores and microfungi during the leaf detritus decomposition in a volcanic lake (Lake Vico – central Italy)
Interactions between detritivores and microfungi during the leaf detritus decomposition in a volcanic lake (Lake Vico – central Italy)
复制标题
火山湖（维科湖 - 意大利中部）叶碎屑分解过程中食碎屑动物和微真菌之间的相互作用
DOI：
10.1023/a:1004149602839
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发表时间：
2000
期刊：
影响因子：
2.6
通讯作者：
L. Rossi
中科院分区：
文献类型：
--
作者：
L. Sabetta;M. Costantini;O. Maggi;A. Persiani;L. Rossi
生物群在芦苇失重中的作用特林。埃克斯·斯图德是在意大利中部一个火山湖的滨海带进行研究的。研究的重点是有害动物和分解真菌之间的取食相互作用，它们是凋落物分解的驱动因素。采用落叶袋法测定了16个采样点40天的叶片质量损失、定植真菌数量和有害生物在叶片上的定植方式。采集海底沉积物的岩心，以估计有机含量和麦角甾醇浓度作为真菌质量的衡量标准。叶片质量损失率在不同采样点之间表现出显著的变异性，并与湖底有机沉降量呈非线性关系，最大值约占干物质的40%。这一比率还与有害物质相对单位叶质量的密度呈正相关，并随时间的延长而增加。在垃圾袋浸泡的第20天，当初始凋落物的残留率为40%时，两种方法的一致性最好，不同采样点之间的有害物质密度差异最小。在没有动物的情况下，腐烂凋落物上的真菌数量与腐解率呈正相关。食害动物的取食活动改变了凋落物上真菌群落的物种丰富度和群落组成。由于大量动物饲养而导致的底物减少，似乎限制了真菌在放牧后重新生长的能力。结果表明，真菌数量与腐解率呈负相关。
The role of biota in the mass loss of Phragmites australis (Cav.) Trin. ex Steud was studied in the littoral belt of a central Italy volcanic lake. The research focussed on the feeding interactions between detritivores and decomposing fungi as drivers of the leaf litter decomposition. The litterbag technique was used to assess the leaf mass loss, the number of colonizing fungi and the patterns of leaf colonization by detritivores during 40 days of submersion in 16 sampling sites. Cores of bottom sediment were collected to estimate the organic content and ergosterol concentration as measure of fungal mass. The rate of leaf mass loss showed significant variability among the sampling sites and was non-linearly related to the quantity of organic depositions onto the lake bottom, peaking at about 40% of the dry matter. The rate was also positively correlated with the density of detritivore mass relative to the leaf unit mass, which increased with time. On the 20th day of litterbag immersion, when 40% of the initial leaf litter remained, we observed the best accordance between the two measures as well as the lowest difference in the detritivore mass density among sampling sites. In the absence of animals, the decomposition rate was positively related to the number of fungi on the decaying litter. The feeding activity of detritivores changed both the species richness and composition of the fungal community on the litter. The substrate reduction due to intense animal feeding appeared to limit the ability of fungi to regrow after grazing. As a result, an inverse relationship between the number of fungi and the decomposition rate was observed.