摘要:

AbstractEcotones may be viewed as boundaries separating adjacent resource patches. They are dynamic components of the aquatic landscape and in the alluvial floodplain they occur as both diffuse and concentrated zones between surface and groundwater environments. This study is focused on a floodplain spring whose water supplies a backwater of the upper Rh6ne River alluvial floodplain (Iles Nouvelles). This paper analyses the community structure on both sides of the physical boundary separating the two ecosystems in relation to hydrological characteristics. The contact between two different environments (surface water and water‐saturated sediment) creates a physical discontinuity which is of great importance for the distribution of aquatic fauna. Two types of organization are described: (1) within the sediment body there are mixed communities (epigean and hypogean) which can move with hydrological variations (biological ecotone) and (2) within the surface‐water body there is a typical epigean fauna which displays a ‘border effect’. The ecological implications of the various patterns of biological responses are discussed as well as the regulatory aspect of the ecotone which minimizes the washout of hypogean fauna towards the surface ec

ISSN:0886-9375    

DOI:10.1002/rrr.3450070112

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe hyporheic zone of two small tributaries of the upper Rhǒne River where they cross the floodplain (approximately 2 km wide) was studied. The streams originate in karstic areas which directly border the floodplain. The surveys were conducted at 11 sites along the course of the two tributaries at a depth of 50 cm in bed sediments. Ten litre samples were collected six times a year with a Bou‐Rouch sampler. The paper examines the distribution of interstitial communities along two transverse (floodplain) profiles, defines the spring ecotone, analyses the heterogeneity, and underlines the importance of the tributaries in the functioning of the floodplain.A comparison between the spatial distributions of fauna and organic matter content along the two profiles underlines the important relationships between the groundwater and surface environment, and makes it possible to differentiate parts of the floodplain where the exchanges are most intense (interstitial spring, karst/floodplain interface). Along the longitudinal course of these streams, we observe the influence of groundwater circulation on community structure/i.e. the interactions between stream channel, alluvial aquifer and adjacent karstic aquif

ISSN:0886-9375    

DOI:10.1002/rrr.3450070113

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450070101

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY