Methane as a carbon source for the food web in raised bog pools
Methane as a carbon source for the food web in raised bog pools
复制标题
甲烷作为高位沼泽池中食物网的碳源
作者：
G. A. V. Duinen;K. Vermonden;P. Bodelier;A. Hendriks;R. Leuven;J. Middelburg;G. V. D. Velde;G. V. D. Velde;W. Verberk
摘要： 养殖的沼泽池营养极其贫乏，腐殖质含量丰富，这些特点限制了初级生产力。为了评估沼泽池塘中无脊椎动物食物网的基础，我们测量了初级生产者、死亡有机物和无脊椎动物的稳定同位素特征，以及它们的磷脂衍生脂肪酸(PLFAs)的组成和稳定碳同位素比率。稳定同位素特征表明，无脊椎动物在物种、个体和大小类别之间和内部存在多个营养水平和对基本食物来源的不同使用。肉食性和杂食性无脊椎动物同化来自藻类的多不饱和脂肪酸(PUFA)，可能还有大型植物的多不饱和脂肪酸，以及甲烷氧化细菌(MOB)特有的脂肪酸。在沼泽池中，部分输送到较高营养水平的细菌生物量来自于暴徒。浮游动物似乎更依赖细菌，而昆虫更依赖藻类。围藻是藻类的主要食物来源，是13C消耗最多的基本食物来源，并被推测为维持无脊椎动物食物网的≥ç。无脊椎动物体内多不饱和脂肪酸的~(13)C值相对枯竭，表明甲烷来源的C可能起作用。我们认为，藻类同化的二氧化碳可能来自MOB。因此，无脊椎动物耗尽的~(13)C值并不一定表明MOB和这些无脊椎动物之间存在直接的途径，因为藻类可能形成中间水平。
Abstract. Raised bog pools are extremely nutrient poor and rich in humic substances, and these features limit primary production. To assess the base of the invertebrate food web in bog pools we measured the stable-isotopic signatures of primary producers, dead organic matter, and invertebrates, and the composition and stable-C-isotope ratio of their phospholipid-derived fatty acids (PLFAs). The stable-isotopic signatures showed the presence of multiple trophic levels and differential use of basal food sources by the invertebrates among and within species, individuals, and size classes. Carnivorous and omnivorous invertebrates assimilated polyunsaturated fatty acids (PUFAs) derived from algae, and possibly macrophytes, and fatty acids that are specific for methane-oxidizing bacteria (MOB). Part of the bacterial biomass conveyed to higher trophic levels in the bog pools originated from MOB. Pelagic zooplankton appeared to rely more on bacteria, whereas insects relied more on algae. Periphyton, a primary algal food source, was the basal food source most depleted in 13C and was inferred to sustain ≥½ the invertebrate food web. The relatively depleted &dgr;13C values of PUFAs in invertebrates suggest a role for methane-derived C. We argue that the CO2 assimilated by the algae could be derived from MOB. Therefore, depleted &dgr;13C values of invertebrates do not necessarily indicate a direct pathway between MOB and these invertebrates because algae may form an intermediate level.
影响因子：
5.1
作者：
Chen, Yin;Dumont, Marc G.;Murrell, J. Colin
通讯作者：
Murrell, J. Colin