Since the 1960s he has been a pioneer of “earth art”.

从20世纪60年代开始，他就是“地景艺术”的先驱。

And the sudden appearance of earth art or land art can be seen as a response to the heightened political activism of the time.

大地艺术或大地艺术的突然出现可以被看作是对当时高度政治激进主义的回应。