ISSN:
1573-5117
Keywords:
community structure
;
ecosystem function
;
Vallisneria
;
mesocosms
;
net primary production
;
nutrients
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Submerged aquatic vegetation is known as a key structural component and regulator in ecosystems. In this mesocosm study, we examine community- and system-level responses to the presence of Vallisneria americana (L), a deep-rooted macrophyte. Phytoplankton, bacteria and filamentous algal biomasses were significantly lowered in the presence of V. americana. In addition, mesocosms with macrophytes had significantly reduced porewater phosphate and iron, water column dissolved organic carbon and total suspended solids, but elevated sediment redox. All mesocosms were net autotrophic (gross primary production/respiration 〉1). Compared to the macrophyte treatments, the control mesocosms had lower diel net primary production (NPP) midway through the experiment (d 16), but at the end of the experiment (d 36), the controls had the higher values, presumably due to increased filamentous algae. NPP and NPP/R were constant in the macrophyte treatments, whereas NPP/R increased significantly from middle to end of the experiment in the controls. We show that community and system-level responses to the presence of V. americana have significant consequences on system structure and function.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1003808220424
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