Responses of microbial decomposers to drought in streams may depend on the environmental context
Responses of microbial decomposers to drought in streams may depend on the environmental context
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DOI：
10.1111/1758-2229.12592
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发表时间：
2017-12-01
影响因子：
3.3
通讯作者：
Pascoal, Claudia
中科院分区：
文献类型：
--
作者：
Duarte, Sofia;Mora-Gomez, Juanita;Pascoal, Claudia
河流干旱的一个后果是分解的落叶重新出现，这可能改变有机物的循环。我们评估了在两种具有不同特征（特别是养分、温度和氧气水平）的河流中，重现对黑杨叶分解和相关微生物（微生物生物量、胞外酶活性和微生物多样性）的影响。受影响最大的水体（高营养、高温度、低氧）叶片分解速率、真菌生物量和胞外酶活性均较低。此外，真菌和细菌群落的结构在河流之间也有所不同。再现强烈影响所有微生物功能测量。叶片分解、真菌生物量和胞外酶活性在最原始的地点更为敏感，而真菌繁殖和细菌生物量生产在最受影响的溪流中更受再现的影响。土壤重现后，微生物群落结构发生了强烈的变化。虽然在两种河流中都发现了对叶片相关微生物的相似影响，但对回归的功能响应可能是由于不同的初始微生物群落对干燥胁迫的敏感性不同。我们的研究强调了了解干旱对遭受不同环境扰动的河流的影响的必要性，因为对重现的反应似乎取决于环境背景。
A consequence of drought in streams is the emersion of decomposing leaf litter, which may alter organic matter recycling. We assessed the effects of emersion on decomposition of black poplar leaves and associated microbes (microbial biomass, extracellular enzyme activities and microbial diversity) in two streams with distinct characteristics, in particular nutrients, temperature and oxygen levels. Leaf decomposition rates, fungal biomass and extracellular enzyme activities were lower in the most impacted stream (high nutrients and temperature, low oxygen). Also, the structure of fungal and bacterial communities differed between streams. Emersion strongly affected all microbial functional measures. Leaf decomposition, fungal biomass and extracellular enzyme activities were more sensitive at the most pristine site, while fungal reproduction and bacterial biomass production were more affected by emersion at the most impacted stream. Microbial community structure was strongly altered after emersion. Although similar effects on leaf-associated microbes were found in both streams, functional responses to emersion differed probably as a consequence of different initial microbial communities with different sensitivity to the drying stress. Our study highlights the need of understanding the effects of drought in streams suffering from different environmental perturbations, since responses to emersion appear to depend on the environmental context.