Dissecting the microbial food web: structure and function in the absence of autotrophs

Aquatic Microbial Ecology

Antoni Martínez-Taberner¹  Eva Sintes¹  Gabriel Moy๠ Guillem Ramon¹ 

关键词: Microbial food web;    Electron transport system activity;    Structure;    Function;    Cave lagoons;    Heterotrophy;   

DOI  :  10.3354/ame037283

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The balance between organic matter producers and consumers defines the metabolism of aquatic ecosystems. Therefore, we can discriminate between net autotrophic and net heterotrophic ecosystems on the basis of the metabolic predominance of eithergroup. Net heterotrophic systems need allochthonous inputs of organic matter. As a model of a heterotrophic ecosystem, we analyzed the structure and function of the microbial food web in littoral cave lagoons of Mallorca (Spain), where trophic food websin the absence of light are sustained by organic matter, which enters the system through seepage. We compared the microplanktonic food web of these lagoons with that of net heterotrophic ecosystems which receive both autochthonous and allochthonousorganic matter. The upper part of the water column has a similar structure and function to that of the oligotrophic open sea, but with a lower abundance and biomass of organisms, with an average of 4.7 × 10⁵ heterotrophic bacteria (HB)ml^-1 and 162 heterotrophic nanoflagellates (HNF) ml^-1. The deep zones are similar to that of the deep sea, with an average bacterial abundance of 2.9 × 10⁵ HB ml^-1 and 48 HNFml^-1 and bacterial production values as low as 0.03 µg C l^-1 d^-1.

【 授权许可】

Unknown