Could someone give me insight in what is wrong with my aralia roble? I purchased the plant about a year ago and it has been doing very well... But now it is slowly losing all its leaves. I't been getting enough water. With winter in the Netherlands its been getting a little less of the usual light. (Of course the plant is indoors.)

Note worthy is that the part in the light in not effected that badly. But the proces slowly seems te speed up and I worried. Would love your reply!

The plant looks like this: http://www.artiplant.com/planten/planten_groot/hydroplanten/Aralia_polyscias_roble.html