Unlike the modern near-infinite procedural generation, Survival Test worlds were small and finite. The world border was a sheer drop into a void or a glass wall (depending on specific sub-versions). In a "03" environment, the world generation seed would have been dictated by the system time, often resulting in the same "default" spawn areas seen in early YouTube tutorials.
Blocks like logs dropped 3–5 planks, and leaves had a 1/10 chance to drop saplings. Primitive Mobs: minecraft 0.24 survival test 03