I am clearing a woodland area so my 10 month old walking son has somewhere to play this summer. It is covered with Dog's Mercury which is poisoness and I am trying to remove it - digging it up seems a hopeless task as its like its all one plant with a huge root system, all intertwined with the tree roots. Does anyone have any hints or tips on how I should go about removing it? Also does anyone know what the symptoms of poisoning from it are? or where I could find out.

Thanks for any help you can give me