Silviculture (8)
I believe the answer is:
forestry
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">silviculture</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for forestry that I've seen before include "expanse of trees" , "Science of trees" , "Growing wood" , "The planting and management of timber" , "(exemplary) elder management?" .)