Trophic interactions and matter fluxes within the macroinvertebrate communities of a Central European mountain and lowland stream

摘要

A modelling approach to ecosystem component connectivity (e.g., Pahl-Wostl 1995) has been applied in marine shallow-water and pelagic systems (e.g., Gaedke et al. 1996, Carrer Opitz 1999) and recently in stream ecosystems (Poepperl 2003, Meyer Poepperl 2004). We apply this approach to two stream ecosystems, for which a broad data base exists, allowing mass-balanced network analysis (Christensen Pauly 1992, 1993, Mavuti et al. 1996). The food webs of a lowland and mountain stream describe trophic interactions of invertebrate groups with the general objective of gaining a more holistic understanding of the structure and functioning of the communities (Townsend et al. 1998, Power Dietrich 2002) by quantitatively describing how matter and energy propagate along food web pathways (Thompson Townsend 2000). Furthermore, a quantitative characterization and classification of the overall system, system parameters and ratios, along with indicators of system performance and developmental stage, are obtained from model outputs.