• 樹木じゅもく — trees
• 果樹かじゅ — fruit tree
• 植樹しょくじゅ — tree planting
• 樹立じゅりつ — establishment
• 風樹ふうじゅ — “wind and tree” (filial piety metaphor)

樹 is a semantic–phonetic compound: the radical 木 (tree) plus the phonetic 尌 (ジュ, “to stand/establish”). It evokes planting or setting something upright and firm—like a tree taking root—hence “to establish.”