HR: 14:45h
AN: NB43D-06    [Abstracts]
TI: Determining Reference Conditions in Western Iberia using Macrophytes
AU: * Ferreira, T
EM: terferreira@isa.utl.pt
AF: Departamento de Engenharia Florestal. Instituto Superior de Agronomia, Tapada da Ajuda, LISBOA, 1349-017 Portugal
AU: Aguiar, F
EM: fraguiar@isa.utl.pt
AF: Departamento de Engenharia Florestal. Instituto Superior de Agronomia, Tapada da Ajuda, LISBOA, 1349-017 Portugal
AU: Gonzalez, P R
EM: patri@isa.utl.pt
AF: Departamento de Engenharia Florestal. Instituto Superior de Agronomia, Tapada da Ajuda, LISBOA, 1349-017 Portugal
AU: Albuquerque, A
EM: aalbuquerque@isa.utl.pt
AF: Departamento de Engenharia Florestal. Instituto Superior de Agronomia, Tapada da Ajuda, LISBOA, 1349-017 Portugal
AU: Santos, J
EM: jmsantos@isa.utl.pt
AF: Departamento de Engenharia Florestal. Instituto Superior de Agronomia, Tapada da Ajuda, LISBOA, 1349-017 Portugal
AB: Are river plants linked with the human-disturbances to a point that they can be used to assess biotic integrity? If so, different groups of river plants should be related to river types and their reference conditions, something yet to be demonstrated, particularly in areas subjected to long-lasting human disturbance, such as the Iberian Peninsula (Western Europe). We analysed the floral variability from 197 least impacted sites and a sub-sample of 156 minimally disturbed, at two spatial scales, the river channel and the river corridor. We aimed to identify plant groups having a reliable ecological response to the hydrological and physical-chemical conditions. Correspondence analyses were applied to floristic data using the two reference-site groups and the two habitat type surveys according to diverse levels of life-form groups (e.g. all species, all waterlogged species, solely hydrophytes) and different alternatives of downscaling rare species. We found an overall weak cohesiveness of plant grouping, for all treatments. From the about 900 species recorded in the fluvial corridors, half were terrestrial species occasionally colonizing the riverbanks. Data treatment showed that in these Mediterranean-type streams, the fluvial corridor approach (discarding terrestrial and rare species) is the best option to establish plant groups and their ecological affiliations.
DE: 1803 Anthropogenic effects
DE: 1845 Limnology
DE: 1851 Plant ecology
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly