INVESTIGADORES
ARCHANGELSKY Miguel
artículos
Título:
Aquatic Coleoptera distribution and environmental relationships in a large Patagonian river.
Autor/es:
MISERENDINO, M. L. & M. ARCHANGELSKY
Revista:
INTERNATIONAL REVIEW OF HYDROBIOLOGY
Editorial:
Wiley
Referencias:
Lugar: Alemania; Año: 2006 vol. 91 p. 423 - 437
ISSN:
1434-2944
Resumen:
The
benthic coleopteran assemblages of the Chubut River basin were studied in order
to assess the main factors affecting species
composition and distribution along the upper, middle and lower catchments. A
total of 13 sampling sites were selected and sampled seasonally. Eight taxa and
1,601 individuals were collected during the study. Richness was higher in the
main channel of Chubut River at the upper basin than at the middle basin.
Beetles were completely absent at the lower basin. Mean monthly density per
sites varied from 0 to 85 ind m2. Stethelmis kaszabi had a more
restricted distribution whereas Hemiosus dejeanii, Austrelmis sp.
and Austrolimnius spp. were more frequent and abundant. Austrelmis sp.
appears as the most tolerant species, especially to higher TSS, ammonia, and
conductivity values. Luchoelmis cekalovici was absent in stations
associated with urban areas. A Canonical Correspondence Analysis shows that
conductivity, total suspended solids, wet width, water temperature and pH were
the most important variables structuring beetle assemblages. Land use related
variables such as NH4, TP, and NO3 were less important but still significant.
An increase in TSS affected negatively the coleopteran community; this could be
related to both hydrogeological characteristics and agricultural activities
(including overgrazing).
This
is the first approach to the knowledge of the ecological range of distribution
of the coleopteran species in Patagonian rivers.