Greetings Deliverance.
" Shajar" means trees in that verse.Compare it to:
22:18
Do you not realize that to God prostrates everyone in the heavens and the earth, and the sun, and the moon, and the stars, and the mountains, and the trees, and the animals, and many people? Many others among the people are committed to doom. Whomever God shames, none will honor him. Everything is in accordance with God's will.
أَلَم تَرَ أَنَّ اللَّهَ يَسجُدُ لَهُ مَن فِى السَّمٰوٰتِ وَمَن فِى الأَرضِ وَالشَّمسُ وَالقَمَرُ وَالنُّجومُ وَالجِبالُ وَالشَّجَرُ وَالدَّوابُّ وَكَثيرٌ مِنَ النّاسِ وَكَثيرٌ حَقَّ عَلَيهِ العَذابُ وَمَن يُهِنِ اللَّهُ فَما لَهُ مِن مُكرِمٍ إِنَّ اللَّهَ يَفعَلُ ما يَشاءُ
It means they comply to GOD s law. They follow the pattern given by GOD through the DNA instruction .They do their job day in day out ,year in year out without opposition/rebellion to their creator.
GOD bless you.
Peace.