Green site organised for nature reserve (9)
I believe the answer is:
serengeti
'nature reserve' is the definition.
'serengeti' can be an answer for 'reserve' (I've seen this before). I am not sure about the 'nature' bit.
'green site organised' is the wordplay.
'organised' indicates anagramming the letters.
'green'+'site'='greensite'
'greensite' with letters rearranged gives 'SERENGETI'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for serengeti that I've seen before include "area of the plain" , "Wildlife-rich region of Africa" , "Huge plain in Tanzania" , "reserve for game" , "area of Tanzania" .)