Yeah. That's what makes the concept of abstract landscape so difficult to even imagine. Now abstract macro, I see that all of the time. But going large is a lot tougher to pull off.
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There are various sub-categories in abstract and one of them is abstract impressionism. So, it is possible to express subtle feelings (impressions) in spite of it being non-figurative.
When I paint a single horizontal line on a canvas (or photograph something similar), and when I give it the title "Landscape with blue sky", the observer is changing his mindset and he is indeed perceiving the abstract picture as a landscape and not as a straight line.
My personal opinion, however, is that an abstract painting or photograph is only abstract when it has no figurative aspects at all, not even in the title. It must be presented totally neutral to the observer. By that definition it is not possible to make an abstract landscape. However, the observer is free to interpret the image as he wants, so he could see it as a landscape.
This last part isn't a generally accepted interpretation of abstract though, it is more one possible sub-category as mentioned in the first paragraph.