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precedente: S2.7
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livello superiore: S2
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seguente: S2.9
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S2.8 - Structural and functional characteristics in an intermittent
Mediterranean-type river ecosystem in relationship to abiotic
factors
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Sangiorgio Franca (1)*,
Fonnesu Alessio (2),
Basset Alberto (1)
| (1) |
Dipart. di Scienze e Tecnologie Biologiche ed Ambientali,
Università degli Studi di Lecce, Provinciale Monteroni, 73100 Lecce,
Italia |
| (2) |
Dipart. di Biologia Animale ed Ecologia, Università degli
Studi di Cagliari, Viale Poetto 1, 09126 Cagliari, Italia |
| * |
franca.sangiorgio@unile.it |
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The relative influence of water regime and abiotic ecosystem features on both
benthic guild structure and Phragmites australis detritus processing was
investigated in Rio Pula basin (Sardinia).
Rio Pula is an intermittent river strongly affected by summer drought events.
The study was carried out at 23 sites in the river Pula basin. Benthic
macroinvertebrates were sampled utilising Surber net seasonally and detritus
processing was measured with leaf pack technique over one year. In addition,
water regime descriptors, physiographic features and physical-chemical factors
as supporting variables were monitored.
Overall, 94 taxa, most of which Insecta, were identified. Taxonomic richness
and benthic guild structure varied with seasons, being taxonomic richness
higher in spring than in fall. Grouping the supporting variables into five
categories (i.e., droughts, abiotic, sediment, space and time), guild
structure was significantly affected only by the time category (CCA).
Reed decay rates varied seasonally too, being higher in wet season at
intermittent sites, and in dry season at constant water flow sites. However,
they varied among sites also. The droughts category explained 44% of decay
rate variance and the abiotic explained 17% (multivariate stepways analysis).
Results suggested that in the Rio Pula basin, benthic guilds were more
resilient to water regime variation than reed detritus processing, being
ecosystem processes mainly driven by water regime intermittence.
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consulta l' Indice analitico (alfabetico per autore) |
sfoglia l' Indice delle sessioni del Congresso |
a cura di Comoglio, Comino, e Bona
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