During a study on the effect of treated sewage effluents on plant cover and soil, I encountered a difficulty in the precise interpretation of the )CCA) diagram, illustrating the relationship between the abundant species and the vegetation characteristics studied for the six sites examined.
From the attached diagram, it looks that all the species examined possess a negative correlation with Suaeda sp. What can we conclude from this observation.
Thank you
Hi,
I highly suggest the book of Leps and Smilauer; Multivariate Analysis of Ecological Data using CANOCO. There is a free download via eg. researchgate. The book provides also case studies including interpretations. It helped me a lot! All the best Michael
My interpretation from the graph and my field experience: Suaeda sp. occupies the wettest saline sites.
In my oppinion, the CCA results can be evaluated in the following sentences
Atriplex seems to be an indicator species illustated the higher biodiversity sites. On this context, second species is Haloxylo. Haloxylo may be another indicator species for higher biodiversity sites
However those species are indicators for higher sites in the case of using I. if u prefer to use 1-D, then Caynodon and Tamarix seems to be better indicator species for diversity.
S, α and D are located in the immediate site of Pulicari in the ordination diagram. It means that Pulicari refers to the sites where species richness is high but diversity seems to be low. In this case, evenness values should be low in this site of the diagram . With regard to Suadea v, I guess that it is found in the sites where species richness and diversity is low