With nature Marx means the discourse at that time, which was based on Ricardo and a specific conception of Nature. In that nature means less gold in the ground, but the world we live in, the materiality of it and with it the ecological interconnectedness of it. "Nature" gives us apple trees and makes apples from them without human labour, but an apple eternally on a tree doesn't feed you, only labour does make it useful. Marx (and Says, Ricardo, Smith, Korpotkin etc.) do agree that there is wealth to be found in nature, that can be exploited alas only with human labour.
Of course there are edge cases like a breathable atmosphere. That however is currently not something with exchange value (only indireclty via tourism)
With nature Marx means the discourse at that time, which was based on Ricardo and a specific conception of Nature. In that nature means less gold in the ground, but the world we live in, the materiality of it and with it the ecological interconnectedness of it. "Nature" gives us apple trees and makes apples from them without human labour, but an apple eternally on a tree doesn't feed you, only labour does make it useful. Marx (and Says, Ricardo, Smith, Korpotkin etc.) do agree that there is wealth to be found in nature, that can be exploited alas only with human labour.
Of course there are edge cases like a breathable atmosphere. That however is currently not something with exchange value (only indireclty via tourism)