The hardened mass of liquid stones had much stronger qualities than those which had simply torn. The skin remained a recognisable part of the molten stone.

I knew the tree when it grew, and the tree is now gone. The farmers cut it up, and it's become firewood. And there's this tremendous sense of absence and shock and violence attendant to that collapsing tree.

The relationship between the public and the artist is complex and difficult to explain. There is a fine line between using this critical energy creatively and pandering to it.

I can't edit the materials I work with. My remit is to work with nature as a whole. I find nature as a whole disturbing. Nature can be harsh – difficult and brutal, as well as beautiful. You couldn't walk five minutes from here without coming across something that is dead or decaying.

I take the opportunity each day offers.

When I was at art school, a lot of art education is about art being a means of self-expression, and as an 18-year-old I didn't know if I had a huge amount I wanted to express. It was a big moment when I decided I wanted to shift the emphasis or the intention of my art from something I disgorged myself upon and something that actually fed me or made me see the world or understand the world.

I am not a performer but occasionally I deliberately work in a public context. Some sculptures need the movement of people around them to work.