The sentence in question:
My attempt at a semi-literal translation:
As for the arising of annual observances, changes in the seasons not only directly influence agricultural matters; they also spring up in various observances which appear in peoples' lives.
I made a lot of guesses in that translation, and I'd appreciate it if you could help me turn those guesses into right or wrong answers.
I think that the antecedent of それが in the second half of the sentence is 季節の移りゆき, which means that it's the subject of the entire sentence (with the predicate being である). Is that correct?
The structure of 国民生活の上に現れて種々の行事 really baffles me. My best guess is that the whole thing is a relative clause describing 行事. Or, more accurately, one relative clause 「国民生活の上に現れて」and one simple modifier 「種々」. Is that in the ballpark, or is the answer something else entirely?
I'm confused about the two uses of 上に in the sentence. At first glance I thought they meant "On top of that...." or "Not only..." but that interpretation doesn't seem to work for the second 上に, which I kind of thought of as functioning as "...appearing on top of people's lives." And if the second 上に can be interpreted that way, then I figure, why can't the first? (I.e., "Changes in the seasons directly influence-on-top-of agricultural matters.") But as far as I know I totally invented this interpretation of 上に, cause it didn't really show up in the dictionaries I looked in. Please let me know.
I think I got the gist of the sentence down, but I'm asking for a really detailed breakdown of all the grammatical things happening inside it, to make sure I really understand it (and also so that I don't come away from this with completely wrong assumptions).
I'd really appreciate it if you could break it down entirely and not just give me your own translation!