This is the 1403rd most frequent Japanese word.
地上
"Ground" or "surface of the earth."
Here, 地上 refers to the surface of the Earth, emphasizing the location where the bird is searching for food.
鳥は地上を歩いて餌を探している。
The bird is walking on the ground looking for food.
In this sentence, 地上 refers to 'on Earth,' denoting the physical world where humans live and explore.
地上の楽園を探し求める旅人たち。
Travelers searching for the paradise on Earth.
地上 embodies the Earth's surface here, underscoring the idea of a physical space inhabited by organisms.