「新聞・雑誌などの編集上の一区分。」This sentence came from one of the definitions for the word 「欄（らん）」 in the "Super Daijirin" dictionary. I'm having trouble honing in on what specific meaning and pronunciation 「上」 could have.
～上【じょう】 is a nominal suffix that has many ways of translation, but here it is used in the sense "in the scope/discussion of —". English does not have a word that consistently matches it, but I hope you can get it from my examples.
編集上のミス an editorial (= during the editing work) error
編集的なミス an editorial (= typically editors-like) error
感覚上の反応 a sensory (= of sensory organ) response
感覚的な反応 an intuitive (= driven by sensation) response
歴史上の事件 a historical (= told in the history) event
歴史的な事件 a historic (= important in the history) event