Velasco Ayuso S, Guerrero M C, Montes C, López-Archilla A I
Departamento de Ecología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Geobiology. 2009 Jan;7(1):66-81. doi: 10.1111/j.1472-4669.2008.00183.x.
The aquifer system of Doñana (SW Spain) represents the most important freshwater source in the Doñana Natural Area. Its spatiotemporal dynamics favours the hydrological connection between surface and subsurface ecosystems, and promotes matter fluxes among the different terrestrial and aquatic systems present here. This aquifer has been intensively studied from a hydrogeological point of view but little is known from an ecological perspective. In order to understand the ecological roles played by microbial communities in this system, we conducted a long-term seasonal study of bacterial abundance, cell biomass, bacterial biomass and functional activities over a 2-year period. Bacterial abundance ranged between 2.11 +/- 1.79 x 10(5) and 8.58 +/- 6.99 x 10(7) bacteria mL(-1) groundwater, average cell biomass was estimated to be 77.01 +/- 31.56 fgC and bacterial biomass varied between 8.99 +/- 4.10 x 10(-2) and 5.65 +/- 0.70 microgC mL(-1). Iron-related bacteria showed the highest activities among the functional groups studied. Moreover, among the variables that usually control spatial distributions of microbial communities in aquifer systems, depth did not have a relevant effect on this aquifer, at least in the range of depths studied, but grain size, probably due to its direct effects on hydrogeological parameters, such as permeability or porosity, appeared to exert moderate control, principally in terms of bacterial abundance. Finally, significant seasonal differences in the means of these microbiological variables were also observed; temperature seems to be the main factor controlling the temporal distribution of microbial communities in this aquifer system.
多尼亚纳（西班牙西南部）的含水层系统是多尼亚纳自然保护区最重要的淡水源。其时空动态有利于地表和地下生态系统之间的水文联系，并促进了此地不同陆地和水生系统之间的物质流动。从水文地质学角度对该含水层进行了深入研究，但从生态学角度了解甚少。为了了解微生物群落在该系统中所起的生态作用，我们在两年时间内对细菌丰度、细胞生物量、细菌生物量和功能活性进行了长期的季节性研究。地下水中细菌丰度在2.11±1.79×10⁵至8.58±6.99×10⁷个细菌/毫升之间，平均细胞生物量估计为77.01±31.56 fgC，细菌生物量在8.99±4.10×10⁻²至5.65±0.70微克C/毫升之间变化。在所研究的功能组中，与铁相关的细菌活性最高。此外，在通常控制含水层系统中微生物群落空间分布的变量中，深度对该含水层没有显著影响，至少在所研究的深度范围内如此，但粒度可能因其对水文地质参数（如渗透率或孔隙率）的直接影响，似乎发挥了适度的控制作用，主要体现在细菌丰度方面。最后，还观察到这些微生物学变量均值存在显著的季节性差异；温度似乎是控制该含水层系统中微生物群落时间分布的主要因素。
