Tree with the power to stand in the Arctic (6)
I believe the answer is:
poplar
'tree' is the definition.
(poplar tree is a kind of tree)
'power to stand in the arctic' is the wordplay.
'power' becomes 'p' (symbol in physics).
'to stand in' is an insertion indicator.
'the arctic' becomes 'polar' (I've seen this in another clue).
'p' going within 'polar' is 'POPLAR'.
'with the' is the link.
(Other definitions for poplar that I've seen before include "Softwood tree with catkins" , "part of London" , "Tall, slender tree" , "Tall fast-growing tree; East London area" , "Tree of willow family" .)