| Title | Diversity and distribution of chironomids (diptera, chironomidae) in pristine alpine and pre-alpine springs (northern Italy) |
| Abstract | The diversity and distribution of chironomids (Diptera, Chironotnidae) were studied in relation to environmental factors in 81 springs under pristine conditions in the Italian Prealps and Alps (Trentino and Veneto, NE-Italy, 46 degrees N, 10-11 degrees E). Each spring was surveyed once, between May and November, in 2005 or in 2007-2008, within 50 m of the spring's source (eucrenal). A total of 173 macroinvertebrate samples were collected, in which 26,871 chironomids (including larvae, pupae, pupal exuviae and adults) were counted. Five subfamilies (Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae), 54 genera and 104 species/groups of species were identified. As expected, Orthocladiinae accounted for a large part of specimens (82%), followed by Diamesinae (10%), Chironominae Tanytarsini (6%) and Tanypodinae (2%). Together the Chironominae Chironomini and Prodiamesinae contributed less than 0.05% of the fauna. Larvae represented 97.5% of specimens, mostly juveniles (62.6%). Maximum richness and diversity occurred at intermediate altitudes (ca 900-2100 m a.s.l.). Most taxa were found in a small proportion of sites, and frequencies declined gradually for more widely distributed species. A high number (67%) of rare (= present in less than 10% of sites) taxa were found. Three to 27 taxa were identified per spring. The rheocrene/rheo-helocrene springs were richest in taxa (generally > 15 taxa), the mineral spring was poorest, with only three taxa. Most taxa were crenophilous, including lentic, rheobiontic and blyophilous taxa. A Principal Component Analysis (PCA) was performed including 98 taxa. Axes were interpreted calculating the correlation coefficients between site scores and 24 environmental factors. The species with the highest scores were Pseudokiefferiella parva, Corynoneura sp. A, Metriocnemus eurynotus gr., Paratrichocladius skirwithensis and Tvetenia calvescens. Five clusters of sites were identified with K-means analysis on the basis of the first and second PCA axes and a Discriminant Analysis was used to detect environmental factors discriminating the clusters: altitude, canopy cover, hydrological regime, pH, and granulometty as percentage of cobbles and stones. The highly individual nature of springs was highlighted; within the same river basin, between springs and within a single spring. These results suggest that prudent and conservative land management should assume that all springs sheltering such unique faunal assemblages need protection. |
| Source | Journal of limnology (Testo stamp.) 70, pp. 106–121 |
| Keywords | Orthocladiinae; biodiversity; eucrenal; spring types; south-eastern Alps |
| Journal | Journal of limnology (Testo stamp.) |
| Editor | Istituto per lo Studio degli Ecosistemi., Verbania Pallanza, Italia |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.3274/JL11-70-S1-08 |
| Authors | Lencioni V., Marziali L., Rossaro B. |
| Text | 42439 2011 10.3274/JL11 70 S1 08 ISI Web of Science WOS 000289588500009 Scopus 2 s2.0 79951587264 Orthocladiinae; biodiversity; eucrenal; spring types; south eastern Alps Diversity and distribution of chironomids diptera, chironomidae in pristine alpine and pre alpine springs northern Italy Lencioni V., Marziali L., Rossaro B. Department of Invertebrate Zoology and Hydrobiology, Museo Tridentino di Scienze Naturali, Via Calepina 14, 38122 Trento, Italy; Water Research Institute CNR IRSA, Via del Mulino 19, 20047 Brugherio MB , Italy; Department of Agri food and Urban Systems Protection, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy The diversity and distribution of chironomids Diptera, Chironotnidae were studied in relation to environmental factors in 81 springs under pristine conditions in the Italian Prealps and Alps Trentino and Veneto, NE Italy, 46 degrees N, 10 11 degrees E . Each spring was surveyed once, between May and November, in 2005 or in 2007 2008, within 50 m of the spring s source eucrenal . A total of 173 macroinvertebrate samples were collected, in which 26,871 chironomids including larvae, pupae, pupal exuviae and adults were counted. Five subfamilies Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae , 54 genera and 104 species/groups of species were identified. As expected, Orthocladiinae accounted for a large part of specimens 82% , followed by Diamesinae 10% , Chironominae Tanytarsini 6% and Tanypodinae 2% . Together the Chironominae Chironomini and Prodiamesinae contributed less than 0.05% of the fauna. Larvae represented 97.5% of specimens, mostly juveniles 62.6% . Maximum richness and diversity occurred at intermediate altitudes ca 900 2100 m a.s.l. . Most taxa were found in a small proportion of sites, and frequencies declined gradually for more widely distributed species. A high number 67% of rare = present in less than 10% of sites taxa were found. Three to 27 taxa were identified per spring. The rheocrene/rheo helocrene springs were richest in taxa generally > 15 taxa , the mineral spring was poorest, with only three taxa. Most taxa were crenophilous, including lentic, rheobiontic and blyophilous taxa. A Principal Component Analysis PCA was performed including 98 taxa. Axes were interpreted calculating the correlation coefficients between site scores and 24 environmental factors. The species with the highest scores were Pseudokiefferiella parva, Corynoneura sp. A, Metriocnemus eurynotus gr., Paratrichocladius skirwithensis and Tvetenia calvescens. Five clusters of sites were identified with K means analysis on the basis of the first and second PCA axes and a Discriminant Analysis was used to detect environmental factors discriminating the clusters altitude, canopy cover, hydrological regime, pH, and granulometty as percentage of cobbles and stones. The highly individual nature of springs was highlighted; within the same river basin, between springs and within a single spring. These results suggest that prudent and conservative land management should assume that all springs sheltering such unique faunal assemblages need protection. 70 Published version http //jlimnol.it/index.php/jlimnol/article/view/jlimnol.2011.s1.106 J. Limnol., 70 Suppl. 1 106 121, 2011 DOI 10.3274/JL11 70 S1 08 01/01/2011 Diversity and distribution of chironomids Diptera, Chironomidae in pristine Alpine and pre Alpine springs Northern Italy Full text Lencioni_etal11_ChironomidaeSprings.pdf Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. laura.marziali MARZIALI LAURA TA.P04.032.003 La risposta delle comunita acquatiche bioindicatori e WFD |
