To make up for the decline, the reaction has been to open up more land by chopping down more forests, creating a vicious cycle.
單位產量降低，只好伐林、墾草原，擴充農耕面積，以求多收穫；然而，森林面積愈減、旱澇愈烈、肥力流失愈劇，產量愈無法提高；於是再伐林……，形成大陸學者余謀昌筆下「愈薄收愈廣種、愈廣種愈薄收」的惡性循環。