Fig. 3

Triplot of standardized PCA results on the data of key variables of streams and habitat types showing the association between streams, habitat types, and key environmental variables on the community composition (abundance) of Garra in the 12 sites of the two study streams (Gereb Tsedo and Elala) and three additional sites downstream of their junction (for identification of streams and sampling locations see Fig. 1). Data of Gereb Tsedo (GTS) stream are represented by filled circles, Elala (ELA) by filled squares, and Mariam Dahan (MD), the common stream of the two streams below their junction, are indicated by filled diamonds. Filled up triangle centroids represent average data of each stream. Filled down triangle centroids represent average data of each habitat type. Gray arrows indicate the important variables as determined by forward selection in the redundancy analysis (Corixidae, Tabanidae, Lymnaeidae, Damselfly larvae, DO, velocity, transparency, depth). Blue arrows represent fish community abundances