Distribución espacial de los Adephaga acuáticos (Coleoptera) en la cuenca del rio Segura (SE de la Península Ibérica)
1996; Volume: 12; Issue: 2 Linguagem: Inglês
10.23818/limn.12.09
ISSN2660-8537
Autores Tópico(s)Orthoptera Research and Taxonomy
ResumoThrce ordination techniques.Multiple Correspondeiicc Analysis (MCA), Multiple Caiionical Correspondence Aiialysis (MCCA) aiid Correspondence Analysis (CA), were applied to characterizc the spatial distribution of the 64 species of aquatic Adcphaga (Coleoptei'a) found in the Segura River basin.Al1 threc ordination inethods gave sirnilar i'esults, being altitude, mineralization of the water, and riparian vegetation the rnost important environmental factors determining thc composition of the asscmblages.A clear gradient from the head waters to the river mouth was detccted, dcfined within a very heterogeneous spatial framework.The analysis of a contingencc table with CA, used as a coinplementary aid to the interpretation of the MCCA, allowed a better ~indcrstanding of the relationship betwcen the species and the environrnentnl variables.Four spccics groups were defined according to the results: l .typical head-water species; 2, species in the inedium plane oí'the river basin; 3, less rnineralized water bodies in the low reach of thc river; and 4 highly inineralized water bodics in the low reach of the river.Some pioneer and opportunistic species, showing a highly spatial plasticity, were í'ound among al1 groups, reducing their differences and contributing to the establishment of a contiriuous biological gradicnt closcly rclated with tlic environrnental gradiente. RESULTADOS MCA: Análisis de Correspondencias Múltiple.En la Tabla 2 aparecen los autovalores o valores principales, inercia e inercia acuinulada del anrílisis para los ejes 1 y 11 , así como las contribuciones absolutas para dichos ejes dc las espccics con valores rnayorcs n 3.
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