In the discussion, have a look if a reader gets the feeling that all this is already known. Be aware, that there is a problem when you are listing several references that got the same result as you did. If you have this kind of a long list, why does science need your study?
Of course, there most probably are articles published with a same result that you got. You should refer to some of them. However, if you do not raise any new finding or aspect and show what is different, it’s an easy task for a reviewer to say that ‘there is nothing new’. You can have and present some confirmatory results, but many editors want that there is something new as well.
Top journals do not want local and confirmatory results at all. They often ask reviewers to assess how generalizable the results are. Even lower quality journal editors have asked me (as a reviewer) to assess if the results are local and just confirmatory to the ones commonly observed previously elsewhere. Now, if you yourself write many times in the discussion that ‘this has been observed previously’, how can any reviewer say anything else than ‘there is nothing new’? Therefore, when you write that your ‘result has been observed previously’, stop and think. Maybe this sentence is best to delete throughout and find another formulation.
What should you write instead then? I cannot give any universal advice, but, in many cases, you can find contradictory observations. Try to read more carefully the papers you are referring, and find what kind of contradictory results and interpretations exist. Which interpretation does your result support?
Many times and most often, you cannot find anything new about the great lines in ecological science. Therefore, you must work more and go into details. Maybe you can explain more about what specifically was found in the references you give, and then, explain what new you had. What in detail?